xref: /dflybsd-src/sys/dev/drm/i915/i915_gem.c (revision 5aa42fef418118d7414e8b76fbb5ae50738ffea0)
1 /*
2  * Copyright © 2008 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  * Authors:
24  *    Eric Anholt <eric@anholt.net>
25  *
26  * Copyright (c) 2011 The FreeBSD Foundation
27  * All rights reserved.
28  *
29  * This software was developed by Konstantin Belousov under sponsorship from
30  * the FreeBSD Foundation.
31  *
32  * Redistribution and use in source and binary forms, with or without
33  * modification, are permitted provided that the following conditions
34  * are met:
35  * 1. Redistributions of source code must retain the above copyright
36  *    notice, this list of conditions and the following disclaimer.
37  * 2. Redistributions in binary form must reproduce the above copyright
38  *    notice, this list of conditions and the following disclaimer in the
39  *    documentation and/or other materials provided with the distribution.
40  *
41  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  */
54 
55 #include <sys/resourcevar.h>
56 #include <sys/sfbuf.h>
57 #include <machine/md_var.h>
58 
59 #include <drm/drmP.h>
60 #include <drm/i915_drm.h>
61 #include "i915_drv.h"
62 #include "i915_trace.h"
63 #include "intel_drv.h"
64 #include <linux/shmem_fs.h>
65 #include <linux/slab.h>
66 #include <linux/pci.h>
67 
68 static void i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj);
69 static void i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj);
70 static __must_check int i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
71 						    unsigned alignment,
72 						    bool map_and_fenceable,
73 						    bool nonblocking);
74 static int i915_gem_phys_pwrite(struct drm_device *dev,
75 				struct drm_i915_gem_object *obj,
76 				struct drm_i915_gem_pwrite *args,
77 				struct drm_file *file);
78 
79 static void i915_gem_write_fence(struct drm_device *dev, int reg,
80 				 struct drm_i915_gem_object *obj);
81 static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
82 					 struct drm_i915_fence_reg *fence,
83 					 bool enable);
84 
85 static long i915_gem_purge(struct drm_i915_private *dev_priv, long target);
86 static void i915_gem_object_truncate(struct drm_i915_gem_object *obj);
87 
88 static inline void i915_gem_object_fence_lost(struct drm_i915_gem_object *obj)
89 {
90 	if (obj->tiling_mode)
91 		i915_gem_release_mmap(obj);
92 
93 	/* As we do not have an associated fence register, we will force
94 	 * a tiling change if we ever need to acquire one.
95 	 */
96 	obj->fence_dirty = false;
97 	obj->fence_reg = I915_FENCE_REG_NONE;
98 }
99 
100 static bool i915_gem_object_is_inactive(struct drm_i915_gem_object *obj);
101 static void i915_gem_lowmem(void *arg);
102 
103 /* some bookkeeping */
104 static void i915_gem_info_add_obj(struct drm_i915_private *dev_priv,
105 				  size_t size)
106 {
107 	dev_priv->mm.object_count++;
108 	dev_priv->mm.object_memory += size;
109 }
110 
111 static void i915_gem_info_remove_obj(struct drm_i915_private *dev_priv,
112 				     size_t size)
113 {
114 	dev_priv->mm.object_count--;
115 	dev_priv->mm.object_memory -= size;
116 }
117 
118 static int
119 i915_gem_wait_for_error(struct i915_gpu_error *error)
120 {
121 	int ret;
122 
123 #define EXIT_COND (!i915_reset_in_progress(error) || \
124 		   i915_terminally_wedged(error))
125 	if (EXIT_COND)
126 		return 0;
127 
128 	/*
129 	 * Only wait 10 seconds for the gpu reset to complete to avoid hanging
130 	 * userspace. If it takes that long something really bad is going on and
131 	 * we should simply try to bail out and fail as gracefully as possible.
132 	 */
133 	ret = wait_event_interruptible_timeout(error->reset_queue,
134 					       EXIT_COND,
135 					       10*HZ);
136 	if (ret == 0) {
137 		DRM_ERROR("Timed out waiting for the gpu reset to complete\n");
138 		return -EIO;
139 	} else if (ret < 0) {
140 		return ret;
141 	}
142 #undef EXIT_COND
143 
144 	return 0;
145 }
146 
147 int i915_mutex_lock_interruptible(struct drm_device *dev)
148 {
149 	struct drm_i915_private *dev_priv = dev->dev_private;
150 	int ret;
151 
152 	ret = i915_gem_wait_for_error(&dev_priv->gpu_error);
153 	if (ret)
154 		return ret;
155 
156 	ret = lockmgr(&dev->struct_mutex, LK_EXCLUSIVE|LK_SLEEPFAIL);
157 	if (ret)
158 		return -EINTR;
159 
160 	WARN_ON(i915_verify_lists(dev));
161 	return 0;
162 }
163 
164 static inline bool
165 i915_gem_object_is_inactive(struct drm_i915_gem_object *obj)
166 {
167 	return !obj->active;
168 }
169 
170 int
171 i915_gem_init_ioctl(struct drm_device *dev, void *data,
172 		    struct drm_file *file)
173 {
174 	struct drm_i915_private *dev_priv = dev->dev_private;
175 	struct drm_i915_gem_init *args = data;
176 
177 	if (drm_core_check_feature(dev, DRIVER_MODESET))
178 		return -ENODEV;
179 
180 	if (args->gtt_start >= args->gtt_end ||
181 	    (args->gtt_end | args->gtt_start) & (PAGE_SIZE - 1))
182 		return -EINVAL;
183 
184 	/* GEM with user mode setting was never supported on ilk and later. */
185 	if (INTEL_INFO(dev)->gen >= 5)
186 		return -ENODEV;
187 
188 	mutex_lock(&dev->struct_mutex);
189 	i915_gem_setup_global_gtt(dev, args->gtt_start, args->gtt_end,
190 				  args->gtt_end);
191 	dev_priv->gtt.mappable_end = args->gtt_end;
192 	mutex_unlock(&dev->struct_mutex);
193 
194 	return 0;
195 }
196 
197 int
198 i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
199 			    struct drm_file *file)
200 {
201 	struct drm_i915_private *dev_priv = dev->dev_private;
202 	struct drm_i915_gem_get_aperture *args = data;
203 	struct drm_i915_gem_object *obj;
204 	size_t pinned;
205 
206 	pinned = 0;
207 	mutex_lock(&dev->struct_mutex);
208 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list)
209 		if (obj->pin_count)
210 			pinned += obj->gtt_space->size;
211 	mutex_unlock(&dev->struct_mutex);
212 
213 	args->aper_size = dev_priv->gtt.total;
214 	args->aper_available_size = args->aper_size - pinned;
215 
216 	return 0;
217 }
218 
219 void i915_gem_object_free(struct drm_i915_gem_object *obj)
220 {
221 	kfree(obj);
222 }
223 
224 static int
225 i915_gem_create(struct drm_file *file,
226 		struct drm_device *dev,
227 		uint64_t size,
228 		uint32_t *handle_p)
229 {
230 	struct drm_i915_gem_object *obj;
231 	int ret;
232 	u32 handle;
233 
234 	size = roundup(size, PAGE_SIZE);
235 	if (size == 0)
236 		return -EINVAL;
237 
238 	/* Allocate the new object */
239 	obj = i915_gem_alloc_object(dev, size);
240 	if (obj == NULL)
241 		return -ENOMEM;
242 
243 	ret = drm_gem_handle_create(file, &obj->base, &handle);
244 	if (ret) {
245 		drm_gem_object_release(&obj->base);
246 		i915_gem_info_remove_obj(dev->dev_private, obj->base.size);
247 		i915_gem_object_free(obj);
248 		return ret;
249 	}
250 
251 	/* drop reference from allocate - handle holds it now */
252 	drm_gem_object_unreference(&obj->base);
253 	trace_i915_gem_object_create(obj);
254 
255 	*handle_p = handle;
256 	return 0;
257 }
258 
259 int
260 i915_gem_dumb_create(struct drm_file *file,
261 		     struct drm_device *dev,
262 		     struct drm_mode_create_dumb *args)
263 {
264 
265 	/* have to work out size/pitch and return them */
266 	args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
267 	args->size = args->pitch * args->height;
268 	return i915_gem_create(file, dev,
269 			       args->size, &args->handle);
270 }
271 
272 int i915_gem_dumb_destroy(struct drm_file *file,
273 			  struct drm_device *dev,
274 			  uint32_t handle)
275 {
276 
277 	return drm_gem_handle_delete(file, handle);
278 }
279 
280 /**
281  * Creates a new mm object and returns a handle to it.
282  */
283 int
284 i915_gem_create_ioctl(struct drm_device *dev, void *data,
285 		      struct drm_file *file)
286 {
287 	struct drm_i915_gem_create *args = data;
288 
289 	return i915_gem_create(file, dev,
290 			       args->size, &args->handle);
291 }
292 
293 static inline int
294 __copy_to_user_swizzled(char __user *cpu_vaddr,
295 			const char *gpu_vaddr, int gpu_offset,
296 			int length)
297 {
298 	int ret, cpu_offset = 0;
299 
300 	while (length > 0) {
301 		int cacheline_end = ALIGN(gpu_offset + 1, 64);
302 		int this_length = min(cacheline_end - gpu_offset, length);
303 		int swizzled_gpu_offset = gpu_offset ^ 64;
304 
305 		ret = __copy_to_user(cpu_vaddr + cpu_offset,
306 				     gpu_vaddr + swizzled_gpu_offset,
307 				     this_length);
308 		if (ret)
309 			return ret + length;
310 
311 		cpu_offset += this_length;
312 		gpu_offset += this_length;
313 		length -= this_length;
314 	}
315 
316 	return 0;
317 }
318 
319 static inline int
320 __copy_from_user_swizzled(char *gpu_vaddr, int gpu_offset,
321 			  const char __user *cpu_vaddr,
322 			  int length)
323 {
324 	int ret, cpu_offset = 0;
325 
326 	while (length > 0) {
327 		int cacheline_end = ALIGN(gpu_offset + 1, 64);
328 		int this_length = min(cacheline_end - gpu_offset, length);
329 		int swizzled_gpu_offset = gpu_offset ^ 64;
330 
331 		ret = __copy_from_user(gpu_vaddr + swizzled_gpu_offset,
332 				       cpu_vaddr + cpu_offset,
333 				       this_length);
334 		if (ret)
335 			return ret + length;
336 
337 		cpu_offset += this_length;
338 		gpu_offset += this_length;
339 		length -= this_length;
340 	}
341 
342 	return 0;
343 }
344 
345 /* Per-page copy function for the shmem pread fastpath.
346  * Flushes invalid cachelines before reading the target if
347  * needs_clflush is set. */
348 static int
349 shmem_pread_fast(struct vm_page *page, int shmem_page_offset, int page_length,
350 		 char __user *user_data,
351 		 bool page_do_bit17_swizzling, bool needs_clflush)
352 {
353 	char *vaddr;
354 	int ret;
355 
356 	if (unlikely(page_do_bit17_swizzling))
357 		return -EINVAL;
358 
359 	vaddr = kmap_atomic(page);
360 	if (needs_clflush)
361 		drm_clflush_virt_range(vaddr + shmem_page_offset,
362 				       page_length);
363 	ret = __copy_to_user_inatomic(user_data,
364 				      vaddr + shmem_page_offset,
365 				      page_length);
366 	kunmap_atomic(vaddr);
367 
368 	return ret ? -EFAULT : 0;
369 }
370 
371 static void
372 shmem_clflush_swizzled_range(char *addr, unsigned long length,
373 			     bool swizzled)
374 {
375 	if (unlikely(swizzled)) {
376 		unsigned long start = (unsigned long) addr;
377 		unsigned long end = (unsigned long) addr + length;
378 
379 		/* For swizzling simply ensure that we always flush both
380 		 * channels. Lame, but simple and it works. Swizzled
381 		 * pwrite/pread is far from a hotpath - current userspace
382 		 * doesn't use it at all. */
383 		start = round_down(start, 128);
384 		end = round_up(end, 128);
385 
386 		drm_clflush_virt_range((void *)start, end - start);
387 	} else {
388 		drm_clflush_virt_range(addr, length);
389 	}
390 
391 }
392 
393 /* Only difference to the fast-path function is that this can handle bit17
394  * and uses non-atomic copy and kmap functions. */
395 static int
396 shmem_pread_slow(struct vm_page *page, int shmem_page_offset, int page_length,
397 		 char __user *user_data,
398 		 bool page_do_bit17_swizzling, bool needs_clflush)
399 {
400 	char *vaddr;
401 	int ret;
402 
403 	vaddr = kmap(page);
404 	if (needs_clflush)
405 		shmem_clflush_swizzled_range(vaddr + shmem_page_offset,
406 					     page_length,
407 					     page_do_bit17_swizzling);
408 
409 	if (page_do_bit17_swizzling)
410 		ret = __copy_to_user_swizzled(user_data,
411 					      vaddr, shmem_page_offset,
412 					      page_length);
413 	else
414 		ret = __copy_to_user(user_data,
415 				     vaddr + shmem_page_offset,
416 				     page_length);
417 	kunmap(page);
418 
419 	return ret ? - EFAULT : 0;
420 }
421 
422 static inline void vm_page_reference(vm_page_t m)
423 {
424 	vm_page_flag_set(m, PG_REFERENCED);
425 }
426 
427 static int
428 i915_gem_shmem_pread(struct drm_device *dev,
429 		     struct drm_i915_gem_object *obj,
430 		     struct drm_i915_gem_pread *args,
431 		     struct drm_file *file)
432 {
433 	char __user *user_data;
434 	ssize_t remain;
435 	off_t offset;
436 	int shmem_page_offset, page_length, ret = 0;
437 	int obj_do_bit17_swizzling, page_do_bit17_swizzling;
438 	int hit_slowpath = 0;
439 	int needs_clflush = 0;
440 	int i;
441 
442 	user_data = (char __user *) (uintptr_t) args->data_ptr;
443 	remain = args->size;
444 
445 	obj_do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj);
446 
447 	if (!(obj->base.read_domains & I915_GEM_DOMAIN_CPU)) {
448 		/* If we're not in the cpu read domain, set ourself into the gtt
449 		 * read domain and manually flush cachelines (if required). This
450 		 * optimizes for the case when the gpu will dirty the data
451 		 * anyway again before the next pread happens. */
452 		if (obj->cache_level == I915_CACHE_NONE)
453 			needs_clflush = 1;
454 		if (obj->gtt_space) {
455 			ret = i915_gem_object_set_to_gtt_domain(obj, false);
456 			if (ret)
457 				return ret;
458 		}
459 	}
460 
461 	ret = i915_gem_object_get_pages(obj);
462 	if (ret)
463 		return ret;
464 
465 	i915_gem_object_pin_pages(obj);
466 
467 	offset = args->offset;
468 
469 	for (i = 0; i < (obj->base.size >> PAGE_SHIFT); i++) {
470 		struct vm_page *page;
471 
472 		if (i < offset >> PAGE_SHIFT)
473 			continue;
474 
475 		if (remain <= 0)
476 			break;
477 
478 		/* Operation in this page
479 		 *
480 		 * shmem_page_offset = offset within page in shmem file
481 		 * page_length = bytes to copy for this page
482 		 */
483 		shmem_page_offset = offset_in_page(offset);
484 		page_length = remain;
485 		if ((shmem_page_offset + page_length) > PAGE_SIZE)
486 			page_length = PAGE_SIZE - shmem_page_offset;
487 
488 #ifdef __linux__
489 		page = sg_page(sg);
490 		page_do_bit17_swizzling = obj_do_bit17_swizzling &&
491 			(page_to_phys(page) & (1 << 17)) != 0;
492 #else
493 		page = obj->pages[i];
494 		page_do_bit17_swizzling = obj_do_bit17_swizzling &&
495 			(VM_PAGE_TO_PHYS(page) & (1 << 17)) != 0;
496 #endif
497 
498 		ret = shmem_pread_fast(page, shmem_page_offset, page_length,
499 				       user_data, page_do_bit17_swizzling,
500 				       needs_clflush);
501 		if (ret == 0)
502 			goto next_page;
503 
504 		hit_slowpath = 1;
505 		mutex_unlock(&dev->struct_mutex);
506 
507 #ifdef __linux__
508 		if (!prefaulted) {
509 			ret = fault_in_multipages_writeable(user_data, remain);
510 			/* Userspace is tricking us, but we've already clobbered
511 			 * its pages with the prefault and promised to write the
512 			 * data up to the first fault. Hence ignore any errors
513 			 * and just continue. */
514 			(void)ret;
515 			prefaulted = 1;
516 		}
517 #endif
518 
519 		ret = shmem_pread_slow(page, shmem_page_offset, page_length,
520 				       user_data, page_do_bit17_swizzling,
521 				       needs_clflush);
522 
523 		mutex_lock(&dev->struct_mutex);
524 
525 next_page:
526 #ifdef __linux__
527 		mark_page_accessed(page);
528 #endif
529 
530 		if (ret)
531 			goto out;
532 
533 		remain -= page_length;
534 		user_data += page_length;
535 		offset += page_length;
536 	}
537 
538 out:
539 	i915_gem_object_unpin_pages(obj);
540 
541 	if (hit_slowpath) {
542 		/* Fixup: Kill any reinstated backing storage pages */
543 		if (obj->madv == __I915_MADV_PURGED)
544 			i915_gem_object_truncate(obj);
545 	}
546 
547 	return ret;
548 }
549 
550 /**
551  * Reads data from the object referenced by handle.
552  *
553  * On error, the contents of *data are undefined.
554  */
555 int
556 i915_gem_pread_ioctl(struct drm_device *dev, void *data,
557 		     struct drm_file *file)
558 {
559 	struct drm_i915_gem_pread *args = data;
560 	struct drm_i915_gem_object *obj;
561 	int ret = 0;
562 
563 	if (args->size == 0)
564 		return 0;
565 
566 	ret = i915_mutex_lock_interruptible(dev);
567 	if (ret)
568 		return ret;
569 
570 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
571 	if (&obj->base == NULL) {
572 		ret = -ENOENT;
573 		goto unlock;
574 	}
575 
576 	/* Bounds check source.  */
577 	if (args->offset > obj->base.size ||
578 	    args->size > obj->base.size - args->offset) {
579 		ret = -EINVAL;
580 		goto out;
581 	}
582 
583 	ret = i915_gem_shmem_pread(dev, obj, args, file);
584 out:
585 	drm_gem_object_unreference(&obj->base);
586 unlock:
587 	mutex_unlock(&dev->struct_mutex);
588 	return ret;
589 }
590 
591 #if 0
592 /* This is the fast write path which cannot handle
593  * page faults in the source data
594  */
595 
596 static inline int
597 fast_user_write(struct io_mapping *mapping,
598 		loff_t page_base, int page_offset,
599 		char __user *user_data,
600 		int length)
601 {
602 	void __iomem *vaddr_atomic;
603 	void *vaddr;
604 	unsigned long unwritten;
605 
606 	vaddr_atomic = io_mapping_map_atomic_wc(mapping, page_base);
607 	/* We can use the cpu mem copy function because this is X86. */
608 	vaddr = (void __force*)vaddr_atomic + page_offset;
609 	unwritten = __copy_from_user_inatomic_nocache(vaddr,
610 						      user_data, length);
611 	io_mapping_unmap_atomic(vaddr_atomic);
612 	return unwritten;
613 }
614 
615 /**
616  * This is the fast pwrite path, where we copy the data directly from the
617  * user into the GTT, uncached.
618  */
619 static int
620 i915_gem_gtt_pwrite_fast(struct drm_device *dev,
621 			 struct drm_i915_gem_object *obj,
622 			 struct drm_i915_gem_pwrite *args,
623 			 struct drm_file *file)
624 {
625 	drm_i915_private_t *dev_priv = dev->dev_private;
626 	ssize_t remain;
627 	loff_t offset, page_base;
628 	char __user *user_data;
629 	int page_offset, page_length, ret;
630 
631 	ret = i915_gem_object_pin(obj, 0, true, true);
632 	if (ret)
633 		goto out;
634 
635 	ret = i915_gem_object_set_to_gtt_domain(obj, true);
636 	if (ret)
637 		goto out_unpin;
638 
639 	ret = i915_gem_object_put_fence(obj);
640 	if (ret)
641 		goto out_unpin;
642 
643 	user_data = to_user_ptr(args->data_ptr);
644 	remain = args->size;
645 
646 	offset = obj->gtt_offset + args->offset;
647 
648 	while (remain > 0) {
649 		/* Operation in this page
650 		 *
651 		 * page_base = page offset within aperture
652 		 * page_offset = offset within page
653 		 * page_length = bytes to copy for this page
654 		 */
655 		page_base = offset & PAGE_MASK;
656 		page_offset = offset_in_page(offset);
657 		page_length = remain;
658 		if ((page_offset + remain) > PAGE_SIZE)
659 			page_length = PAGE_SIZE - page_offset;
660 
661 		/* If we get a fault while copying data, then (presumably) our
662 		 * source page isn't available.  Return the error and we'll
663 		 * retry in the slow path.
664 		 */
665 		if (fast_user_write(dev_priv->gtt.mappable, page_base,
666 				    page_offset, user_data, page_length)) {
667 			ret = -EFAULT;
668 			goto out_unpin;
669 		}
670 
671 		remain -= page_length;
672 		user_data += page_length;
673 		offset += page_length;
674 	}
675 
676 out_unpin:
677 	i915_gem_object_unpin(obj);
678 out:
679 	return ret;
680 }
681 #endif
682 
683 static int
684 i915_gem_gtt_write(struct drm_device *dev, struct drm_i915_gem_object *obj,
685     uint64_t data_ptr, uint64_t size, uint64_t offset, struct drm_file *file)
686 {
687 	vm_offset_t mkva;
688 	int ret;
689 
690 	/*
691 	 * Pass the unaligned physical address and size to pmap_mapdev_attr()
692 	 * so it can properly calculate whether an extra page needs to be
693 	 * mapped or not to cover the requested range.  The function will
694 	 * add the page offset into the returned mkva for us.
695 	 */
696 	mkva = (vm_offset_t)pmap_mapdev_attr(dev->agp->base + obj->gtt_offset +
697 	    offset, size, PAT_WRITE_COMBINING);
698 	ret = -copyin_nofault((void *)(uintptr_t)data_ptr, (char *)mkva, size);
699 	pmap_unmapdev(mkva, size);
700 	return ret;
701 }
702 
703 #if 0
704 /* Per-page copy function for the shmem pwrite fastpath.
705  * Flushes invalid cachelines before writing to the target if
706  * needs_clflush_before is set and flushes out any written cachelines after
707  * writing if needs_clflush is set. */
708 static int
709 shmem_pwrite_fast(struct vm_page *page, int shmem_page_offset, int page_length,
710 		  char __user *user_data,
711 		  bool page_do_bit17_swizzling,
712 		  bool needs_clflush_before,
713 		  bool needs_clflush_after)
714 {
715 	char *vaddr;
716 	int ret;
717 
718 	if (unlikely(page_do_bit17_swizzling))
719 		return -EINVAL;
720 
721 	vaddr = kmap_atomic(page);
722 	if (needs_clflush_before)
723 		drm_clflush_virt_range(vaddr + shmem_page_offset,
724 				       page_length);
725 	ret = __copy_from_user_inatomic_nocache(vaddr + shmem_page_offset,
726 						user_data,
727 						page_length);
728 	if (needs_clflush_after)
729 		drm_clflush_virt_range(vaddr + shmem_page_offset,
730 				       page_length);
731 	kunmap_atomic(vaddr);
732 
733 	return ret ? -EFAULT : 0;
734 }
735 
736 /* Only difference to the fast-path function is that this can handle bit17
737  * and uses non-atomic copy and kmap functions. */
738 static int
739 shmem_pwrite_slow(struct vm_page *page, int shmem_page_offset, int page_length,
740 		  char __user *user_data,
741 		  bool page_do_bit17_swizzling,
742 		  bool needs_clflush_before,
743 		  bool needs_clflush_after)
744 {
745 	char *vaddr;
746 	int ret;
747 
748 	vaddr = kmap(page);
749 	if (unlikely(needs_clflush_before || page_do_bit17_swizzling))
750 		shmem_clflush_swizzled_range(vaddr + shmem_page_offset,
751 					     page_length,
752 					     page_do_bit17_swizzling);
753 	if (page_do_bit17_swizzling)
754 		ret = __copy_from_user_swizzled(vaddr, shmem_page_offset,
755 						user_data,
756 						page_length);
757 	else
758 		ret = __copy_from_user(vaddr + shmem_page_offset,
759 				       user_data,
760 				       page_length);
761 	if (needs_clflush_after)
762 		shmem_clflush_swizzled_range(vaddr + shmem_page_offset,
763 					     page_length,
764 					     page_do_bit17_swizzling);
765 	kunmap(page);
766 
767 	return ret ? -EFAULT : 0;
768 }
769 #endif
770 
771 static int
772 i915_gem_shmem_pwrite(struct drm_device *dev,
773 		      struct drm_i915_gem_object *obj,
774 		      struct drm_i915_gem_pwrite *args,
775 		      struct drm_file *file)
776 {
777 	vm_object_t vm_obj;
778 	vm_page_t m;
779 	struct sf_buf *sf;
780 	vm_offset_t mkva;
781 	vm_pindex_t obj_pi;
782 	int cnt, do_bit17_swizzling, length, obj_po, ret, swizzled_po;
783 
784 	do_bit17_swizzling = 0;
785 
786 	obj->dirty = 1;
787 	vm_obj = obj->base.vm_obj;
788 	ret = 0;
789 
790 	VM_OBJECT_LOCK(vm_obj);
791 	vm_object_pip_add(vm_obj, 1);
792 	while (args->size > 0) {
793 		obj_pi = OFF_TO_IDX(args->offset);
794 		obj_po = args->offset & PAGE_MASK;
795 
796 		m = shmem_read_mapping_page(vm_obj, obj_pi);
797 		VM_OBJECT_UNLOCK(vm_obj);
798 
799 		sf = sf_buf_alloc(m);
800 		mkva = sf_buf_kva(sf);
801 		length = min(args->size, PAGE_SIZE - obj_po);
802 		while (length > 0) {
803 			if (do_bit17_swizzling &&
804 			    (VM_PAGE_TO_PHYS(m) & (1 << 17)) != 0) {
805 				cnt = roundup2(obj_po + 1, 64);
806 				cnt = min(cnt - obj_po, length);
807 				swizzled_po = obj_po ^ 64;
808 			} else {
809 				cnt = length;
810 				swizzled_po = obj_po;
811 			}
812 			ret = -copyin_nofault(
813 			    (void *)(uintptr_t)args->data_ptr,
814 			    (char *)mkva + swizzled_po, cnt);
815 			if (ret != 0)
816 				break;
817 			args->data_ptr += cnt;
818 			args->size -= cnt;
819 			length -= cnt;
820 			args->offset += cnt;
821 			obj_po += cnt;
822 		}
823 		sf_buf_free(sf);
824 		VM_OBJECT_LOCK(vm_obj);
825 		vm_page_dirty(m);
826 		vm_page_reference(m);
827 		vm_page_busy_wait(m, FALSE, "i915gem");
828 		vm_page_unwire(m, 1);
829 		vm_page_wakeup(m);
830 
831 		if (ret != 0)
832 			break;
833 	}
834 	vm_object_pip_wakeup(vm_obj);
835 	VM_OBJECT_UNLOCK(vm_obj);
836 
837 	return (ret);
838 }
839 
840 /**
841  * Writes data to the object referenced by handle.
842  *
843  * On error, the contents of the buffer that were to be modified are undefined.
844  */
845 int
846 i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
847 		      struct drm_file *file)
848 {
849 	struct drm_i915_gem_pwrite *args = data;
850 	struct drm_i915_gem_object *obj;
851 	vm_page_t *ma;
852 	vm_offset_t start, end;
853 	int npages, ret;
854 
855 	if (args->size == 0)
856 		return 0;
857 
858 	start = trunc_page(args->data_ptr);
859 	end = round_page(args->data_ptr + args->size);
860 	npages = howmany(end - start, PAGE_SIZE);
861 	ma = kmalloc(npages * sizeof(vm_page_t), M_DRM, M_WAITOK |
862 	    M_ZERO);
863 	npages = vm_fault_quick_hold_pages(&curproc->p_vmspace->vm_map,
864 	    (vm_offset_t)args->data_ptr, args->size,
865 	    VM_PROT_READ, ma, npages);
866 	if (npages == -1) {
867 		ret = -EFAULT;
868 		goto free_ma;
869 	}
870 
871 	ret = i915_mutex_lock_interruptible(dev);
872 	if (ret != 0)
873 		goto unlocked;
874 
875 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
876 	if (&obj->base == NULL) {
877 		ret = -ENOENT;
878 		goto unlock;
879 	}
880 
881 	/* Bounds check destination. */
882 	if (args->offset > obj->base.size ||
883 	    args->size > obj->base.size - args->offset) {
884 		ret = -EINVAL;
885 		goto out;
886 	}
887 
888 	if (obj->phys_obj) {
889 		ret = i915_gem_phys_pwrite(dev, obj, args, file);
890 	} else if (obj->gtt_space &&
891 		    obj->base.write_domain != I915_GEM_DOMAIN_CPU) {
892 		ret = i915_gem_object_pin(obj, 0, true, false);
893 		if (ret != 0)
894 			goto out;
895 		ret = i915_gem_object_set_to_gtt_domain(obj, true);
896 		if (ret != 0)
897 			goto out_unpin;
898 		ret = i915_gem_object_put_fence(obj);
899 		if (ret != 0)
900 			goto out_unpin;
901 		ret = i915_gem_gtt_write(dev, obj, args->data_ptr, args->size,
902 		    args->offset, file);
903 out_unpin:
904 		i915_gem_object_unpin(obj);
905 	} else {
906 		ret = i915_gem_object_set_to_cpu_domain(obj, true);
907 		if (ret != 0)
908 			goto out;
909 		ret = i915_gem_shmem_pwrite(dev, obj, args, file);
910 	}
911 out:
912 	drm_gem_object_unreference(&obj->base);
913 unlock:
914 	mutex_unlock(&dev->struct_mutex);
915 unlocked:
916 	vm_page_unhold_pages(ma, npages);
917 free_ma:
918 	drm_free(ma, M_DRM);
919 	return ret;
920 }
921 
922 int
923 i915_gem_check_wedge(struct i915_gpu_error *error,
924 		     bool interruptible)
925 {
926 	if (i915_reset_in_progress(error)) {
927 		/* Non-interruptible callers can't handle -EAGAIN, hence return
928 		 * -EIO unconditionally for these. */
929 		if (!interruptible)
930 			return -EIO;
931 
932 		/* Recovery complete, but the reset failed ... */
933 		if (i915_terminally_wedged(error))
934 			return -EIO;
935 
936 		return -EAGAIN;
937 	}
938 
939 	return 0;
940 }
941 
942 /*
943  * Compare seqno against outstanding lazy request. Emit a request if they are
944  * equal.
945  */
946 static int
947 i915_gem_check_olr(struct intel_ring_buffer *ring, u32 seqno)
948 {
949 	int ret;
950 
951 	DRM_LOCK_ASSERT(ring->dev);
952 
953 	ret = 0;
954 	if (seqno == ring->outstanding_lazy_request)
955 		ret = i915_add_request(ring, NULL);
956 
957 	return ret;
958 }
959 
960 /**
961  * __wait_seqno - wait until execution of seqno has finished
962  * @ring: the ring expected to report seqno
963  * @seqno: duh!
964  * @reset_counter: reset sequence associated with the given seqno
965  * @interruptible: do an interruptible wait (normally yes)
966  * @timeout: in - how long to wait (NULL forever); out - how much time remaining
967  *
968  * Note: It is of utmost importance that the passed in seqno and reset_counter
969  * values have been read by the caller in an smp safe manner. Where read-side
970  * locks are involved, it is sufficient to read the reset_counter before
971  * unlocking the lock that protects the seqno. For lockless tricks, the
972  * reset_counter _must_ be read before, and an appropriate smp_rmb must be
973  * inserted.
974  *
975  * Returns 0 if the seqno was found within the alloted time. Else returns the
976  * errno with remaining time filled in timeout argument.
977  */
978 static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,
979 			unsigned reset_counter,
980 			bool interruptible, struct timespec *timeout)
981 {
982 	drm_i915_private_t *dev_priv = ring->dev->dev_private;
983 	struct timespec before, now, wait_time={1,0};
984 	unsigned long timeout_jiffies;
985 	long end;
986 	bool wait_forever = true;
987 	int ret;
988 
989 	if (i915_seqno_passed(ring->get_seqno(ring, true), seqno))
990 		return 0;
991 
992 	if (timeout != NULL) {
993 		wait_time = *timeout;
994 		wait_forever = false;
995 	}
996 
997 	timeout_jiffies = timespec_to_jiffies_timeout(&wait_time);
998 
999 	if (WARN_ON(!ring->irq_get(ring)))
1000 		return -ENODEV;
1001 
1002 	/* Record current time in case interrupted by signal, or wedged * */
1003 	getrawmonotonic(&before);
1004 
1005 #define EXIT_COND \
1006 	(i915_seqno_passed(ring->get_seqno(ring, false), seqno) || \
1007 	 i915_reset_in_progress(&dev_priv->gpu_error) || \
1008 	 reset_counter != atomic_read(&dev_priv->gpu_error.reset_counter))
1009 	do {
1010 		if (interruptible)
1011 			end = wait_event_interruptible_timeout(ring->irq_queue,
1012 							       EXIT_COND,
1013 							       timeout_jiffies);
1014 		else
1015 			end = wait_event_timeout(ring->irq_queue, EXIT_COND,
1016 						 timeout_jiffies);
1017 
1018 		/* We need to check whether any gpu reset happened in between
1019 		 * the caller grabbing the seqno and now ... */
1020 		if (reset_counter != atomic_read(&dev_priv->gpu_error.reset_counter))
1021 			end = -EAGAIN;
1022 
1023 		/* ... but upgrade the -EGAIN to an -EIO if the gpu is truely
1024 		 * gone. */
1025 		ret = i915_gem_check_wedge(&dev_priv->gpu_error, interruptible);
1026 		if (ret)
1027 			end = ret;
1028 	} while (end == 0 && wait_forever);
1029 
1030 	getrawmonotonic(&now);
1031 
1032 	ring->irq_put(ring);
1033 #undef EXIT_COND
1034 
1035 	if (timeout) {
1036 		struct timespec sleep_time = timespec_sub(now, before);
1037 		*timeout = timespec_sub(*timeout, sleep_time);
1038 		if (!timespec_valid(timeout)) /* i.e. negative time remains */
1039 			set_normalized_timespec(timeout, 0, 0);
1040 	}
1041 
1042 	switch (end) {
1043 	case -EIO:
1044 	case -EAGAIN: /* Wedged */
1045 	case -ERESTARTSYS: /* Signal */
1046 		return (int)end;
1047 	case 0: /* Timeout */
1048 		return -ETIMEDOUT;	/* -ETIME on Linux */
1049 	default: /* Completed */
1050 		WARN_ON(end < 0); /* We're not aware of other errors */
1051 		return 0;
1052 	}
1053 }
1054 
1055 /**
1056  * Waits for a sequence number to be signaled, and cleans up the
1057  * request and object lists appropriately for that event.
1058  */
1059 int
1060 i915_wait_seqno(struct intel_ring_buffer *ring, uint32_t seqno)
1061 {
1062 	struct drm_device *dev = ring->dev;
1063 	struct drm_i915_private *dev_priv = dev->dev_private;
1064 	bool interruptible = dev_priv->mm.interruptible;
1065 	int ret;
1066 
1067 	DRM_LOCK_ASSERT(dev);
1068 	BUG_ON(seqno == 0);
1069 
1070 	ret = i915_gem_check_wedge(&dev_priv->gpu_error, interruptible);
1071 	if (ret)
1072 		return ret;
1073 
1074 	ret = i915_gem_check_olr(ring, seqno);
1075 	if (ret)
1076 		return ret;
1077 
1078 	return __wait_seqno(ring, seqno,
1079 			    atomic_read(&dev_priv->gpu_error.reset_counter),
1080 			    interruptible, NULL);
1081 }
1082 
1083 static int
1084 i915_gem_object_wait_rendering__tail(struct drm_i915_gem_object *obj,
1085 				     struct intel_ring_buffer *ring)
1086 {
1087 	i915_gem_retire_requests_ring(ring);
1088 
1089 	/* Manually manage the write flush as we may have not yet
1090 	 * retired the buffer.
1091 	 *
1092 	 * Note that the last_write_seqno is always the earlier of
1093 	 * the two (read/write) seqno, so if we haved successfully waited,
1094 	 * we know we have passed the last write.
1095 	 */
1096 	obj->last_write_seqno = 0;
1097 	obj->base.write_domain &= ~I915_GEM_GPU_DOMAINS;
1098 
1099 	return 0;
1100 }
1101 
1102 /**
1103  * Ensures that all rendering to the object has completed and the object is
1104  * safe to unbind from the GTT or access from the CPU.
1105  */
1106 static __must_check int
1107 i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,
1108 			       bool readonly)
1109 {
1110 	struct intel_ring_buffer *ring = obj->ring;
1111 	u32 seqno;
1112 	int ret;
1113 
1114 	seqno = readonly ? obj->last_write_seqno : obj->last_read_seqno;
1115 	if (seqno == 0)
1116 		return 0;
1117 
1118 	ret = i915_wait_seqno(ring, seqno);
1119 	if (ret)
1120 		return ret;
1121 
1122 	return i915_gem_object_wait_rendering__tail(obj, ring);
1123 }
1124 
1125 /* A nonblocking variant of the above wait. This is a highly dangerous routine
1126  * as the object state may change during this call.
1127  */
1128 static __must_check int
1129 i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
1130 					    bool readonly)
1131 {
1132 	struct drm_device *dev = obj->base.dev;
1133 	struct drm_i915_private *dev_priv = dev->dev_private;
1134 	struct intel_ring_buffer *ring = obj->ring;
1135 	unsigned reset_counter;
1136 	u32 seqno;
1137 	int ret;
1138 
1139 	DRM_LOCK_ASSERT(dev);
1140 	BUG_ON(!dev_priv->mm.interruptible);
1141 
1142 	seqno = readonly ? obj->last_write_seqno : obj->last_read_seqno;
1143 	if (seqno == 0)
1144 		return 0;
1145 
1146 	ret = i915_gem_check_wedge(&dev_priv->gpu_error, true);
1147 	if (ret)
1148 		return ret;
1149 
1150 	ret = i915_gem_check_olr(ring, seqno);
1151 	if (ret)
1152 		return ret;
1153 
1154 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
1155 	mutex_unlock(&dev->struct_mutex);
1156 	ret = __wait_seqno(ring, seqno, reset_counter, true, NULL);
1157 	mutex_lock(&dev->struct_mutex);
1158 	if (ret)
1159 		return ret;
1160 
1161 	return i915_gem_object_wait_rendering__tail(obj, ring);
1162 }
1163 
1164 /**
1165  * Called when user space prepares to use an object with the CPU, either
1166  * through the mmap ioctl's mapping or a GTT mapping.
1167  */
1168 int
1169 i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
1170 			  struct drm_file *file)
1171 {
1172 	struct drm_i915_gem_set_domain *args = data;
1173 	struct drm_i915_gem_object *obj;
1174 	uint32_t read_domains = args->read_domains;
1175 	uint32_t write_domain = args->write_domain;
1176 	int ret;
1177 
1178 	/* Only handle setting domains to types used by the CPU. */
1179 	if (write_domain & I915_GEM_GPU_DOMAINS)
1180 		return -EINVAL;
1181 
1182 	if (read_domains & I915_GEM_GPU_DOMAINS)
1183 		return -EINVAL;
1184 
1185 	/* Having something in the write domain implies it's in the read
1186 	 * domain, and only that read domain.  Enforce that in the request.
1187 	 */
1188 	if (write_domain != 0 && read_domains != write_domain)
1189 		return -EINVAL;
1190 
1191 	ret = i915_mutex_lock_interruptible(dev);
1192 	if (ret)
1193 		return ret;
1194 
1195 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
1196 	if (&obj->base == NULL) {
1197 		ret = -ENOENT;
1198 		goto unlock;
1199 	}
1200 
1201 	/* Try to flush the object off the GPU without holding the lock.
1202 	 * We will repeat the flush holding the lock in the normal manner
1203 	 * to catch cases where we are gazumped.
1204 	 */
1205 	ret = i915_gem_object_wait_rendering__nonblocking(obj, !write_domain);
1206 	if (ret)
1207 		goto unref;
1208 
1209 	if (read_domains & I915_GEM_DOMAIN_GTT) {
1210 		ret = i915_gem_object_set_to_gtt_domain(obj, write_domain != 0);
1211 
1212 		/* Silently promote "you're not bound, there was nothing to do"
1213 		 * to success, since the client was just asking us to
1214 		 * make sure everything was done.
1215 		 */
1216 		if (ret == -EINVAL)
1217 			ret = 0;
1218 	} else {
1219 		ret = i915_gem_object_set_to_cpu_domain(obj, write_domain != 0);
1220 	}
1221 
1222 unref:
1223 	drm_gem_object_unreference(&obj->base);
1224 unlock:
1225 	mutex_unlock(&dev->struct_mutex);
1226 	return ret;
1227 }
1228 
1229 /**
1230  * Called when user space has done writes to this buffer
1231  */
1232 int
1233 i915_gem_sw_finish_ioctl(struct drm_device *dev, void *data,
1234 			 struct drm_file *file)
1235 {
1236 	struct drm_i915_gem_sw_finish *args = data;
1237 	struct drm_i915_gem_object *obj;
1238 	int ret = 0;
1239 
1240 	ret = i915_mutex_lock_interruptible(dev);
1241 	if (ret)
1242 		return ret;
1243 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
1244 	if (&obj->base == NULL) {
1245 		ret = -ENOENT;
1246 		goto unlock;
1247 	}
1248 
1249 	/* Pinned buffers may be scanout, so flush the cache */
1250 	if (obj->pin_count)
1251 		i915_gem_object_flush_cpu_write_domain(obj);
1252 
1253 	drm_gem_object_unreference(&obj->base);
1254 unlock:
1255 	mutex_unlock(&dev->struct_mutex);
1256 	return ret;
1257 }
1258 
1259 /**
1260  * Maps the contents of an object, returning the address it is mapped
1261  * into.
1262  *
1263  * While the mapping holds a reference on the contents of the object, it doesn't
1264  * imply a ref on the object itself.
1265  */
1266 int
1267 i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
1268 		    struct drm_file *file)
1269 {
1270 	struct drm_i915_gem_mmap *args = data;
1271 	struct drm_gem_object *obj;
1272 	struct proc *p = curproc;
1273 	vm_map_t map = &p->p_vmspace->vm_map;
1274 	vm_offset_t addr;
1275 	vm_size_t size;
1276 	int error = 0, rv;
1277 
1278 	obj = drm_gem_object_lookup(dev, file, args->handle);
1279 	if (obj == NULL)
1280 		return -ENOENT;
1281 
1282 	if (args->size == 0)
1283 		goto out;
1284 
1285 	size = round_page(args->size);
1286 	if (map->size + size > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
1287 		error = ENOMEM;
1288 		goto out;
1289 	}
1290 
1291 	addr = 0;
1292 	vm_object_hold(obj->vm_obj);
1293 	vm_object_reference_locked(obj->vm_obj);
1294 	vm_object_drop(obj->vm_obj);
1295 	rv = vm_map_find(map, obj->vm_obj, NULL,
1296 			 args->offset, &addr, args->size,
1297 			 PAGE_SIZE, /* align */
1298 			 TRUE, /* fitit */
1299 			 VM_MAPTYPE_NORMAL, /* maptype */
1300 			 VM_PROT_READ | VM_PROT_WRITE, /* prot */
1301 			 VM_PROT_READ | VM_PROT_WRITE, /* max */
1302 			 MAP_SHARED /* cow */);
1303 	if (rv != KERN_SUCCESS) {
1304 		vm_object_deallocate(obj->vm_obj);
1305 		error = -vm_mmap_to_errno(rv);
1306 	} else {
1307 		args->addr_ptr = (uint64_t)addr;
1308 	}
1309 out:
1310 	drm_gem_object_unreference(obj);
1311 	return (error);
1312 }
1313 
1314 int i915_intr_pf;
1315 
1316 /**
1317  * i915_gem_fault - fault a page into the GTT
1318  * vma: VMA in question
1319  * vmf: fault info
1320  *
1321  * The fault handler is set up by drm_gem_mmap() when a object is GTT mapped
1322  * from userspace.  The fault handler takes care of binding the object to
1323  * the GTT (if needed), allocating and programming a fence register (again,
1324  * only if needed based on whether the old reg is still valid or the object
1325  * is tiled) and inserting a new PTE into the faulting process.
1326  *
1327  * Note that the faulting process may involve evicting existing objects
1328  * from the GTT and/or fence registers to make room.  So performance may
1329  * suffer if the GTT working set is large or there are few fence registers
1330  * left.
1331  */
1332 int
1333 i915_gem_fault(vm_object_t vm_obj, vm_ooffset_t offset, int prot,
1334     vm_page_t *mres)
1335 {
1336 	struct drm_gem_object *gem_obj;
1337 	struct drm_i915_gem_object *obj;
1338 	struct drm_device *dev;
1339 	drm_i915_private_t *dev_priv;
1340 	vm_page_t m, oldm;
1341 	int cause, ret;
1342 	bool write;
1343 
1344 	gem_obj = vm_obj->handle;
1345 	obj = to_intel_bo(gem_obj);
1346 	dev = obj->base.dev;
1347 	dev_priv = dev->dev_private;
1348 #if 0
1349 	write = (prot & VM_PROT_WRITE) != 0;
1350 #else
1351 	write = true;
1352 #endif
1353 	vm_object_pip_add(vm_obj, 1);
1354 
1355 	/*
1356 	 * Remove the placeholder page inserted by vm_fault() from the
1357 	 * object before dropping the object lock. If
1358 	 * i915_gem_release_mmap() is active in parallel on this gem
1359 	 * object, then it owns the drm device sx and might find the
1360 	 * placeholder already. Then, since the page is busy,
1361 	 * i915_gem_release_mmap() sleeps waiting for the busy state
1362 	 * of the page cleared. We will be not able to acquire drm
1363 	 * device lock until i915_gem_release_mmap() is able to make a
1364 	 * progress.
1365 	 */
1366 	if (*mres != NULL) {
1367 		oldm = *mres;
1368 		vm_page_remove(oldm);
1369 		*mres = NULL;
1370 	} else
1371 		oldm = NULL;
1372 retry:
1373 	VM_OBJECT_UNLOCK(vm_obj);
1374 unlocked_vmobj:
1375 	cause = ret = 0;
1376 	m = NULL;
1377 
1378 	if (i915_intr_pf) {
1379 		ret = i915_mutex_lock_interruptible(dev);
1380 		if (ret != 0) {
1381 			cause = 10;
1382 			goto out;
1383 		}
1384 	} else
1385 		mutex_lock(&dev->struct_mutex);
1386 
1387 	/*
1388 	 * Since the object lock was dropped, other thread might have
1389 	 * faulted on the same GTT address and instantiated the
1390 	 * mapping for the page.  Recheck.
1391 	 */
1392 	VM_OBJECT_LOCK(vm_obj);
1393 	m = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
1394 	if (m != NULL) {
1395 		if ((m->flags & PG_BUSY) != 0) {
1396 			mutex_unlock(&dev->struct_mutex);
1397 #if 0 /* XXX */
1398 			vm_page_sleep(m, "915pee");
1399 #endif
1400 			goto retry;
1401 		}
1402 		goto have_page;
1403 	} else
1404 		VM_OBJECT_UNLOCK(vm_obj);
1405 
1406 	/* Access to snoopable pages through the GTT is incoherent. */
1407 	if (obj->cache_level != I915_CACHE_NONE && !HAS_LLC(dev)) {
1408 		ret = -EINVAL;
1409 		goto unlock;
1410 	}
1411 
1412 	/* Now bind it into the GTT if needed */
1413 	if (!obj->map_and_fenceable) {
1414 		ret = i915_gem_object_unbind(obj);
1415 		if (ret != 0) {
1416 			cause = 20;
1417 			goto unlock;
1418 		}
1419 	}
1420 	if (!obj->gtt_space) {
1421 		ret = i915_gem_object_bind_to_gtt(obj, 0, true, false);
1422 		if (ret != 0) {
1423 			cause = 30;
1424 			goto unlock;
1425 		}
1426 
1427 		ret = i915_gem_object_set_to_gtt_domain(obj, write);
1428 		if (ret != 0) {
1429 			cause = 40;
1430 			goto unlock;
1431 		}
1432 	}
1433 
1434 	if (obj->tiling_mode == I915_TILING_NONE)
1435 		ret = i915_gem_object_put_fence(obj);
1436 	else
1437 		ret = i915_gem_object_get_fence(obj);
1438 	if (ret != 0) {
1439 		cause = 50;
1440 		goto unlock;
1441 	}
1442 
1443 	if (i915_gem_object_is_inactive(obj))
1444 		list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
1445 
1446 	obj->fault_mappable = true;
1447 	VM_OBJECT_LOCK(vm_obj);
1448 	m = vm_phys_fictitious_to_vm_page(dev->agp->base + obj->gtt_offset +
1449 	    offset);
1450 	if (m == NULL) {
1451 		cause = 60;
1452 		ret = -EFAULT;
1453 		goto unlock;
1454 	}
1455 	KASSERT((m->flags & PG_FICTITIOUS) != 0,
1456 	    ("not fictitious %p", m));
1457 	KASSERT(m->wire_count == 1, ("wire_count not 1 %p", m));
1458 
1459 	if ((m->flags & PG_BUSY) != 0) {
1460 		mutex_unlock(&dev->struct_mutex);
1461 #if 0 /* XXX */
1462 		vm_page_sleep(m, "915pbs");
1463 #endif
1464 		goto retry;
1465 	}
1466 	m->valid = VM_PAGE_BITS_ALL;
1467 	vm_page_insert(m, vm_obj, OFF_TO_IDX(offset));
1468 have_page:
1469 	*mres = m;
1470 	vm_page_busy_try(m, false);
1471 
1472 	mutex_unlock(&dev->struct_mutex);
1473 	if (oldm != NULL) {
1474 		vm_page_free(oldm);
1475 	}
1476 	vm_object_pip_wakeup(vm_obj);
1477 	return (VM_PAGER_OK);
1478 
1479 unlock:
1480 	mutex_unlock(&dev->struct_mutex);
1481 out:
1482 	KASSERT(ret != 0, ("i915_gem_pager_fault: wrong return"));
1483 	if (ret == -EAGAIN || ret == -EIO || ret == -EINTR) {
1484 		goto unlocked_vmobj;
1485 	}
1486 	VM_OBJECT_LOCK(vm_obj);
1487 	vm_object_pip_wakeup(vm_obj);
1488 	return (VM_PAGER_ERROR);
1489 }
1490 
1491 /**
1492  * i915_gem_release_mmap - remove physical page mappings
1493  * @obj: obj in question
1494  *
1495  * Preserve the reservation of the mmapping with the DRM core code, but
1496  * relinquish ownership of the pages back to the system.
1497  *
1498  * It is vital that we remove the page mapping if we have mapped a tiled
1499  * object through the GTT and then lose the fence register due to
1500  * resource pressure. Similarly if the object has been moved out of the
1501  * aperture, than pages mapped into userspace must be revoked. Removing the
1502  * mapping will then trigger a page fault on the next user access, allowing
1503  * fixup by i915_gem_fault().
1504  */
1505 void
1506 i915_gem_release_mmap(struct drm_i915_gem_object *obj)
1507 {
1508 	vm_object_t devobj;
1509 	vm_page_t m;
1510 	int i, page_count;
1511 
1512 	if (!obj->fault_mappable)
1513 		return;
1514 
1515 	devobj = cdev_pager_lookup(obj);
1516 	if (devobj != NULL) {
1517 		page_count = OFF_TO_IDX(obj->base.size);
1518 
1519 		VM_OBJECT_LOCK(devobj);
1520 		for (i = 0; i < page_count; i++) {
1521 			m = vm_page_lookup_busy_wait(devobj, i, TRUE, "915unm");
1522 			if (m == NULL)
1523 				continue;
1524 			cdev_pager_free_page(devobj, m);
1525 		}
1526 		VM_OBJECT_UNLOCK(devobj);
1527 		vm_object_deallocate(devobj);
1528 	}
1529 
1530 	obj->fault_mappable = false;
1531 }
1532 
1533 uint32_t
1534 i915_gem_get_gtt_size(struct drm_device *dev, uint32_t size, int tiling_mode)
1535 {
1536 	uint32_t gtt_size;
1537 
1538 	if (INTEL_INFO(dev)->gen >= 4 ||
1539 	    tiling_mode == I915_TILING_NONE)
1540 		return size;
1541 
1542 	/* Previous chips need a power-of-two fence region when tiling */
1543 	if (INTEL_INFO(dev)->gen == 3)
1544 		gtt_size = 1024*1024;
1545 	else
1546 		gtt_size = 512*1024;
1547 
1548 	while (gtt_size < size)
1549 		gtt_size <<= 1;
1550 
1551 	return gtt_size;
1552 }
1553 
1554 /**
1555  * i915_gem_get_gtt_alignment - return required GTT alignment for an object
1556  * @obj: object to check
1557  *
1558  * Return the required GTT alignment for an object, taking into account
1559  * potential fence register mapping.
1560  */
1561 uint32_t
1562 i915_gem_get_gtt_alignment(struct drm_device *dev, uint32_t size,
1563 			   int tiling_mode, bool fenced)
1564 {
1565 
1566 	/*
1567 	 * Minimum alignment is 4k (GTT page size), but might be greater
1568 	 * if a fence register is needed for the object.
1569 	 */
1570 	if (INTEL_INFO(dev)->gen >= 4 || (!fenced && IS_G33(dev)) ||
1571 	    tiling_mode == I915_TILING_NONE)
1572 		return 4096;
1573 
1574 	/*
1575 	 * Previous chips need to be aligned to the size of the smallest
1576 	 * fence register that can contain the object.
1577 	 */
1578 	return i915_gem_get_gtt_size(dev, size, tiling_mode);
1579 }
1580 
1581 int
1582 i915_gem_mmap_gtt(struct drm_file *file,
1583 		  struct drm_device *dev,
1584 		  uint32_t handle,
1585 		  uint64_t *offset)
1586 {
1587 	struct drm_i915_private *dev_priv = dev->dev_private;
1588 	struct drm_i915_gem_object *obj;
1589 	int ret;
1590 
1591 	ret = i915_mutex_lock_interruptible(dev);
1592 	if (ret)
1593 		return ret;
1594 
1595 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, handle));
1596 	if (&obj->base == NULL) {
1597 		ret = -ENOENT;
1598 		goto unlock;
1599 	}
1600 
1601 	if (obj->base.size > dev_priv->gtt.mappable_end) {
1602 		ret = -E2BIG;
1603 		goto out;
1604 	}
1605 
1606 	if (obj->madv != I915_MADV_WILLNEED) {
1607 		DRM_ERROR("Attempting to mmap a purgeable buffer\n");
1608 		ret = -EINVAL;
1609 		goto out;
1610 	}
1611 
1612 	ret = drm_gem_create_mmap_offset(&obj->base);
1613 	if (ret)
1614 		goto out;
1615 
1616 	*offset = DRM_GEM_MAPPING_OFF(obj->base.map_list.key) |
1617 	    DRM_GEM_MAPPING_KEY;
1618 out:
1619 	drm_gem_object_unreference(&obj->base);
1620 unlock:
1621 	mutex_unlock(&dev->struct_mutex);
1622 	return ret;
1623 }
1624 
1625 /**
1626  * i915_gem_mmap_gtt_ioctl - prepare an object for GTT mmap'ing
1627  * @dev: DRM device
1628  * @data: GTT mapping ioctl data
1629  * @file: GEM object info
1630  *
1631  * Simply returns the fake offset to userspace so it can mmap it.
1632  * The mmap call will end up in drm_gem_mmap(), which will set things
1633  * up so we can get faults in the handler above.
1634  *
1635  * The fault handler will take care of binding the object into the GTT
1636  * (since it may have been evicted to make room for something), allocating
1637  * a fence register, and mapping the appropriate aperture address into
1638  * userspace.
1639  */
1640 int
1641 i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
1642 			struct drm_file *file)
1643 {
1644 	struct drm_i915_gem_mmap_gtt *args = data;
1645 
1646 	return i915_gem_mmap_gtt(file, dev, args->handle, &args->offset);
1647 }
1648 
1649 /* Immediately discard the backing storage */
1650 static void
1651 i915_gem_object_truncate(struct drm_i915_gem_object *obj)
1652 {
1653 	vm_object_t vm_obj;
1654 
1655 	vm_obj = obj->base.vm_obj;
1656 	VM_OBJECT_LOCK(vm_obj);
1657 	vm_object_page_remove(vm_obj, 0, 0, false);
1658 	VM_OBJECT_UNLOCK(vm_obj);
1659 	obj->madv = __I915_MADV_PURGED;
1660 }
1661 
1662 static inline int
1663 i915_gem_object_is_purgeable(struct drm_i915_gem_object *obj)
1664 {
1665 	return obj->madv == I915_MADV_DONTNEED;
1666 }
1667 
1668 static void
1669 i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
1670 {
1671 	vm_page_t m;
1672 	int page_count, i;
1673 
1674 	BUG_ON(obj->madv == __I915_MADV_PURGED);
1675 
1676 	if (obj->tiling_mode != I915_TILING_NONE)
1677 		i915_gem_object_save_bit_17_swizzle(obj);
1678 	if (obj->madv == I915_MADV_DONTNEED)
1679 		obj->dirty = 0;
1680 	page_count = obj->base.size / PAGE_SIZE;
1681 	VM_OBJECT_LOCK(obj->base.vm_obj);
1682 #if GEM_PARANOID_CHECK_GTT
1683 	i915_gem_assert_pages_not_mapped(obj->base.dev, obj->pages, page_count);
1684 #endif
1685 	for (i = 0; i < page_count; i++) {
1686 		m = obj->pages[i];
1687 		if (obj->dirty)
1688 			vm_page_dirty(m);
1689 		if (obj->madv == I915_MADV_WILLNEED)
1690 			vm_page_reference(m);
1691 		vm_page_busy_wait(obj->pages[i], FALSE, "i915gem");
1692 		vm_page_unwire(obj->pages[i], 1);
1693 		vm_page_wakeup(obj->pages[i]);
1694 	}
1695 	VM_OBJECT_UNLOCK(obj->base.vm_obj);
1696 	obj->dirty = 0;
1697 	drm_free(obj->pages, M_DRM);
1698 	obj->pages = NULL;
1699 }
1700 
1701 int
1702 i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
1703 {
1704 	const struct drm_i915_gem_object_ops *ops = obj->ops;
1705 
1706 	if (obj->pages == NULL)
1707 		return 0;
1708 
1709 	BUG_ON(obj->gtt_space);
1710 
1711 	if (obj->pages_pin_count)
1712 		return -EBUSY;
1713 
1714 	/* ->put_pages might need to allocate memory for the bit17 swizzle
1715 	 * array, hence protect them from being reaped by removing them from gtt
1716 	 * lists early. */
1717 	list_del(&obj->global_list);
1718 
1719 	ops->put_pages(obj);
1720 	obj->pages = NULL;
1721 
1722 	if (i915_gem_object_is_purgeable(obj))
1723 		i915_gem_object_truncate(obj);
1724 
1725 	return 0;
1726 }
1727 
1728 static int
1729 i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
1730 {
1731 	struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
1732 	struct drm_device *dev;
1733 	vm_object_t vm_obj;
1734 	int page_count, i, j;
1735 	struct vm_page *page;
1736 
1737 	dev = obj->base.dev;
1738 	KASSERT(obj->pages == NULL, ("Obj already has pages"));
1739 	page_count = obj->base.size / PAGE_SIZE;
1740 	obj->pages = kmalloc(page_count * sizeof(vm_page_t), M_DRM,
1741 	    M_WAITOK);
1742 
1743 	vm_obj = obj->base.vm_obj;
1744 	VM_OBJECT_LOCK(vm_obj);
1745 
1746 	for (i = 0; i < page_count; i++) {
1747 		page = shmem_read_mapping_page(vm_obj, i);
1748 		if (IS_ERR(page)) {
1749 			i915_gem_purge(dev_priv, page_count);
1750 			goto err_pages;
1751 		}
1752 
1753 		obj->pages[i] = page;
1754 	}
1755 
1756 	VM_OBJECT_UNLOCK(vm_obj);
1757 	if (i915_gem_object_needs_bit17_swizzle(obj))
1758 		i915_gem_object_do_bit_17_swizzle(obj);
1759 
1760 	return 0;
1761 
1762 err_pages:
1763 	for (j = 0; j < i; j++) {
1764 		page = obj->pages[j];
1765 		vm_page_busy_wait(page, FALSE, "i915gem");
1766 		vm_page_unwire(page, 0);
1767 		vm_page_wakeup(page);
1768 	}
1769 	VM_OBJECT_UNLOCK(vm_obj);
1770 	drm_free(obj->pages, M_DRM);
1771 	obj->pages = NULL;
1772 	return (-EIO);
1773 }
1774 
1775 /* Ensure that the associated pages are gathered from the backing storage
1776  * and pinned into our object. i915_gem_object_get_pages() may be called
1777  * multiple times before they are released by a single call to
1778  * i915_gem_object_put_pages() - once the pages are no longer referenced
1779  * either as a result of memory pressure (reaping pages under the shrinker)
1780  * or as the object is itself released.
1781  */
1782 int
1783 i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
1784 {
1785 	struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
1786 	const struct drm_i915_gem_object_ops *ops = obj->ops;
1787 	int ret;
1788 
1789 	if (obj->pages)
1790 		return 0;
1791 
1792 	if (obj->madv != I915_MADV_WILLNEED) {
1793 		DRM_ERROR("Attempting to obtain a purgeable object\n");
1794 		return -EINVAL;
1795 	}
1796 
1797 	BUG_ON(obj->pages_pin_count);
1798 
1799 	ret = ops->get_pages(obj);
1800 	if (ret)
1801 		return ret;
1802 
1803 	list_add_tail(&obj->global_list, &dev_priv->mm.unbound_list);
1804 	return 0;
1805 }
1806 
1807 void
1808 i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
1809 			       struct intel_ring_buffer *ring)
1810 {
1811 	struct drm_device *dev = obj->base.dev;
1812 	struct drm_i915_private *dev_priv = dev->dev_private;
1813 	u32 seqno = intel_ring_get_seqno(ring);
1814 
1815 	BUG_ON(ring == NULL);
1816 	if (obj->ring != ring && obj->last_write_seqno) {
1817 		/* Keep the seqno relative to the current ring */
1818 		obj->last_write_seqno = seqno;
1819 	}
1820 	obj->ring = ring;
1821 
1822 	/* Add a reference if we're newly entering the active list. */
1823 	if (!obj->active) {
1824 		drm_gem_object_reference(&obj->base);
1825 		obj->active = 1;
1826 	}
1827 
1828 	/* Move from whatever list we were on to the tail of execution. */
1829 	list_move_tail(&obj->mm_list, &dev_priv->mm.active_list);
1830 	list_move_tail(&obj->ring_list, &ring->active_list);
1831 
1832 	obj->last_read_seqno = seqno;
1833 
1834 	if (obj->fenced_gpu_access) {
1835 		obj->last_fenced_seqno = seqno;
1836 
1837 		/* Bump MRU to take account of the delayed flush */
1838 		if (obj->fence_reg != I915_FENCE_REG_NONE) {
1839 			struct drm_i915_fence_reg *reg;
1840 
1841 			reg = &dev_priv->fence_regs[obj->fence_reg];
1842 			list_move_tail(&reg->lru_list,
1843 				       &dev_priv->mm.fence_list);
1844 		}
1845 	}
1846 }
1847 
1848 static void
1849 i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
1850 {
1851 	struct drm_device *dev = obj->base.dev;
1852 	struct drm_i915_private *dev_priv = dev->dev_private;
1853 
1854 	BUG_ON(obj->base.write_domain & ~I915_GEM_GPU_DOMAINS);
1855 	BUG_ON(!obj->active);
1856 
1857 	list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
1858 
1859 	list_del_init(&obj->ring_list);
1860 	obj->ring = NULL;
1861 
1862 	obj->last_read_seqno = 0;
1863 	obj->last_write_seqno = 0;
1864 	obj->base.write_domain = 0;
1865 
1866 	obj->last_fenced_seqno = 0;
1867 	obj->fenced_gpu_access = false;
1868 
1869 	obj->active = 0;
1870 	drm_gem_object_unreference(&obj->base);
1871 
1872 	WARN_ON(i915_verify_lists(dev));
1873 }
1874 
1875 static int
1876 i915_gem_init_seqno(struct drm_device *dev, u32 seqno)
1877 {
1878 	struct drm_i915_private *dev_priv = dev->dev_private;
1879 	struct intel_ring_buffer *ring;
1880 	int ret, i, j;
1881 
1882 	/* Carefully retire all requests without writing to the rings */
1883 	for_each_ring(ring, dev_priv, i) {
1884 		ret = intel_ring_idle(ring);
1885 		if (ret)
1886 			return ret;
1887 	}
1888 	i915_gem_retire_requests(dev);
1889 
1890 	/* Finally reset hw state */
1891 	for_each_ring(ring, dev_priv, i) {
1892 		intel_ring_init_seqno(ring, seqno);
1893 
1894 		for (j = 0; j < ARRAY_SIZE(ring->sync_seqno); j++)
1895 			ring->sync_seqno[j] = 0;
1896 	}
1897 
1898 	return 0;
1899 }
1900 
1901 int i915_gem_set_seqno(struct drm_device *dev, u32 seqno)
1902 {
1903 	struct drm_i915_private *dev_priv = dev->dev_private;
1904 	int ret;
1905 
1906 	if (seqno == 0)
1907 		return -EINVAL;
1908 
1909 	/* HWS page needs to be set less than what we
1910 	 * will inject to ring
1911 	 */
1912 	ret = i915_gem_init_seqno(dev, seqno - 1);
1913 	if (ret)
1914 		return ret;
1915 
1916 	/* Carefully set the last_seqno value so that wrap
1917 	 * detection still works
1918 	 */
1919 	dev_priv->next_seqno = seqno;
1920 	dev_priv->last_seqno = seqno - 1;
1921 	if (dev_priv->last_seqno == 0)
1922 		dev_priv->last_seqno--;
1923 
1924 	return 0;
1925 }
1926 
1927 int
1928 i915_gem_get_seqno(struct drm_device *dev, u32 *seqno)
1929 {
1930 	struct drm_i915_private *dev_priv = dev->dev_private;
1931 
1932 	/* reserve 0 for non-seqno */
1933 	if (dev_priv->next_seqno == 0) {
1934 		int ret = i915_gem_init_seqno(dev, 0);
1935 		if (ret)
1936 			return ret;
1937 
1938 		dev_priv->next_seqno = 1;
1939 	}
1940 
1941 	*seqno = dev_priv->last_seqno = dev_priv->next_seqno++;
1942 	return 0;
1943 }
1944 
1945 int __i915_add_request(struct intel_ring_buffer *ring,
1946 		       struct drm_file *file,
1947 		       struct drm_i915_gem_object *obj,
1948 		       u32 *out_seqno)
1949 {
1950 	drm_i915_private_t *dev_priv = ring->dev->dev_private;
1951 	struct drm_i915_gem_request *request;
1952 	u32 request_ring_position, request_start;
1953 	int was_empty;
1954 	int ret;
1955 
1956 	request_start = intel_ring_get_tail(ring);
1957 	/*
1958 	 * Emit any outstanding flushes - execbuf can fail to emit the flush
1959 	 * after having emitted the batchbuffer command. Hence we need to fix
1960 	 * things up similar to emitting the lazy request. The difference here
1961 	 * is that the flush _must_ happen before the next request, no matter
1962 	 * what.
1963 	 */
1964 	ret = intel_ring_flush_all_caches(ring);
1965 	if (ret)
1966 		return ret;
1967 
1968 	request = kmalloc(sizeof(*request), M_DRM, M_WAITOK);
1969 	if (request == NULL)
1970 		return -ENOMEM;
1971 
1972 
1973 	/* Record the position of the start of the request so that
1974 	 * should we detect the updated seqno part-way through the
1975 	 * GPU processing the request, we never over-estimate the
1976 	 * position of the head.
1977 	 */
1978 	request_ring_position = intel_ring_get_tail(ring);
1979 
1980 	ret = ring->add_request(ring);
1981 	if (ret) {
1982 		kfree(request);
1983 		return ret;
1984 	}
1985 
1986 	request->seqno = intel_ring_get_seqno(ring);
1987 	request->ring = ring;
1988 	request->head = request_start;
1989 	request->tail = request_ring_position;
1990 	request->ctx = ring->last_context;
1991 	request->batch_obj = obj;
1992 
1993 	/* Whilst this request exists, batch_obj will be on the
1994 	 * active_list, and so will hold the active reference. Only when this
1995 	 * request is retired will the the batch_obj be moved onto the
1996 	 * inactive_list and lose its active reference. Hence we do not need
1997 	 * to explicitly hold another reference here.
1998 	 */
1999 
2000 	if (request->ctx)
2001 		i915_gem_context_reference(request->ctx);
2002 
2003 	request->emitted_jiffies = jiffies;
2004 	was_empty = list_empty(&ring->request_list);
2005 	list_add_tail(&request->list, &ring->request_list);
2006 	request->file_priv = NULL;
2007 
2008 	if (file) {
2009 		struct drm_i915_file_private *file_priv = file->driver_priv;
2010 
2011 		spin_lock(&file_priv->mm.lock);
2012 		request->file_priv = file_priv;
2013 		list_add_tail(&request->client_list,
2014 			      &file_priv->mm.request_list);
2015 		spin_unlock(&file_priv->mm.lock);
2016 	}
2017 
2018 	ring->outstanding_lazy_request = 0;
2019 
2020 	if (!dev_priv->mm.suspended) {
2021 		if (i915_enable_hangcheck) {
2022 			mod_timer(&dev_priv->gpu_error.hangcheck_timer,
2023 				  round_jiffies_up(jiffies + DRM_I915_HANGCHECK_JIFFIES));
2024 		}
2025 		if (was_empty) {
2026 			queue_delayed_work(dev_priv->wq,
2027 					   &dev_priv->mm.retire_work,
2028 					   round_jiffies_up_relative(hz));
2029 			intel_mark_busy(dev_priv->dev);
2030 		}
2031 	}
2032 
2033 	if (out_seqno)
2034 		*out_seqno = request->seqno;
2035 	return 0;
2036 }
2037 
2038 static inline void
2039 i915_gem_request_remove_from_client(struct drm_i915_gem_request *request)
2040 {
2041 	struct drm_i915_file_private *file_priv = request->file_priv;
2042 
2043 	if (!file_priv)
2044 		return;
2045 
2046 	spin_lock(&file_priv->mm.lock);
2047 	if (request->file_priv) {
2048 		list_del(&request->client_list);
2049 		request->file_priv = NULL;
2050 	}
2051 	spin_unlock(&file_priv->mm.lock);
2052 }
2053 
2054 static bool i915_head_inside_object(u32 acthd, struct drm_i915_gem_object *obj)
2055 {
2056 	if (acthd >= obj->gtt_offset &&
2057 	    acthd < obj->gtt_offset + obj->base.size)
2058 		return true;
2059 
2060 	return false;
2061 }
2062 
2063 static bool i915_head_inside_request(const u32 acthd_unmasked,
2064 				     const u32 request_start,
2065 				     const u32 request_end)
2066 {
2067 	const u32 acthd = acthd_unmasked & HEAD_ADDR;
2068 
2069 	if (request_start < request_end) {
2070 		if (acthd >= request_start && acthd < request_end)
2071 			return true;
2072 	} else if (request_start > request_end) {
2073 		if (acthd >= request_start || acthd < request_end)
2074 			return true;
2075 	}
2076 
2077 	return false;
2078 }
2079 
2080 static bool i915_request_guilty(struct drm_i915_gem_request *request,
2081 				const u32 acthd, bool *inside)
2082 {
2083 	/* There is a possibility that unmasked head address
2084 	 * pointing inside the ring, matches the batch_obj address range.
2085 	 * However this is extremely unlikely.
2086 	 */
2087 
2088 	if (request->batch_obj) {
2089 		if (i915_head_inside_object(acthd, request->batch_obj)) {
2090 			*inside = true;
2091 			return true;
2092 		}
2093 	}
2094 
2095 	if (i915_head_inside_request(acthd, request->head, request->tail)) {
2096 		*inside = false;
2097 		return true;
2098 	}
2099 
2100 	return false;
2101 }
2102 
2103 static void i915_set_reset_status(struct intel_ring_buffer *ring,
2104 				  struct drm_i915_gem_request *request,
2105 				  u32 acthd)
2106 {
2107 	struct i915_ctx_hang_stats *hs = NULL;
2108 	bool inside, guilty;
2109 
2110 	/* Innocent until proven guilty */
2111 	guilty = false;
2112 
2113 	if (ring->hangcheck.action != wait &&
2114 	    i915_request_guilty(request, acthd, &inside)) {
2115 		DRM_ERROR("%s hung %s bo (0x%x ctx %d) at 0x%x\n",
2116 			  ring->name,
2117 			  inside ? "inside" : "flushing",
2118 			  request->batch_obj ?
2119 			  request->batch_obj->gtt_offset : 0,
2120 			  request->ctx ? request->ctx->id : 0,
2121 			  acthd);
2122 
2123 		guilty = true;
2124 	}
2125 
2126 	/* If contexts are disabled or this is the default context, use
2127 	 * file_priv->reset_state
2128 	 */
2129 	if (request->ctx && request->ctx->id != DEFAULT_CONTEXT_ID)
2130 		hs = &request->ctx->hang_stats;
2131 	else if (request->file_priv)
2132 		hs = &request->file_priv->hang_stats;
2133 
2134 	if (hs) {
2135 		if (guilty)
2136 			hs->batch_active++;
2137 		else
2138 			hs->batch_pending++;
2139 	}
2140 }
2141 
2142 static void i915_gem_free_request(struct drm_i915_gem_request *request)
2143 {
2144 	list_del(&request->list);
2145 	i915_gem_request_remove_from_client(request);
2146 
2147 	if (request->ctx)
2148 		i915_gem_context_unreference(request->ctx);
2149 
2150 	kfree(request);
2151 }
2152 
2153 static void i915_gem_reset_ring_lists(struct drm_i915_private *dev_priv,
2154 				      struct intel_ring_buffer *ring)
2155 {
2156 	u32 completed_seqno;
2157 	u32 acthd;
2158 
2159 	acthd = intel_ring_get_active_head(ring);
2160 	completed_seqno = ring->get_seqno(ring, false);
2161 
2162 	while (!list_empty(&ring->request_list)) {
2163 		struct drm_i915_gem_request *request;
2164 
2165 		request = list_first_entry(&ring->request_list,
2166 					   struct drm_i915_gem_request,
2167 					   list);
2168 
2169 		if (request->seqno > completed_seqno)
2170 			i915_set_reset_status(ring, request, acthd);
2171 
2172 		i915_gem_free_request(request);
2173 	}
2174 
2175 	while (!list_empty(&ring->active_list)) {
2176 		struct drm_i915_gem_object *obj;
2177 
2178 		obj = list_first_entry(&ring->active_list,
2179 				       struct drm_i915_gem_object,
2180 				       ring_list);
2181 
2182 		i915_gem_object_move_to_inactive(obj);
2183 	}
2184 }
2185 
2186 void i915_gem_restore_fences(struct drm_device *dev)
2187 {
2188 	struct drm_i915_private *dev_priv = dev->dev_private;
2189 	int i;
2190 
2191 	for (i = 0; i < dev_priv->num_fence_regs; i++) {
2192 		struct drm_i915_fence_reg *reg = &dev_priv->fence_regs[i];
2193 
2194 		/*
2195 		 * Commit delayed tiling changes if we have an object still
2196 		 * attached to the fence, otherwise just clear the fence.
2197 		 */
2198 		if (reg->obj) {
2199 			i915_gem_object_update_fence(reg->obj, reg,
2200 						     reg->obj->tiling_mode);
2201 		} else {
2202 			i915_gem_write_fence(dev, i, NULL);
2203 		}
2204 	}
2205 }
2206 
2207 void i915_gem_reset(struct drm_device *dev)
2208 {
2209 	struct drm_i915_private *dev_priv = dev->dev_private;
2210 	struct drm_i915_gem_object *obj;
2211 	struct intel_ring_buffer *ring;
2212 	int i;
2213 
2214 	for_each_ring(ring, dev_priv, i)
2215 		i915_gem_reset_ring_lists(dev_priv, ring);
2216 
2217 	/* Move everything out of the GPU domains to ensure we do any
2218 	 * necessary invalidation upon reuse.
2219 	 */
2220 	list_for_each_entry(obj,
2221 			    &dev_priv->mm.inactive_list,
2222 			    mm_list)
2223 	{
2224 		obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
2225 	}
2226 
2227 	i915_gem_restore_fences(dev);
2228 }
2229 
2230 /**
2231  * This function clears the request list as sequence numbers are passed.
2232  */
2233 void
2234 i915_gem_retire_requests_ring(struct intel_ring_buffer *ring)
2235 {
2236 	uint32_t seqno;
2237 
2238 	if (list_empty(&ring->request_list))
2239 		return;
2240 
2241 	WARN_ON(i915_verify_lists(ring->dev));
2242 
2243 	seqno = ring->get_seqno(ring, true);
2244 
2245 	while (!list_empty(&ring->request_list)) {
2246 		struct drm_i915_gem_request *request;
2247 
2248 		request = list_first_entry(&ring->request_list,
2249 					   struct drm_i915_gem_request,
2250 					   list);
2251 
2252 		if (!i915_seqno_passed(seqno, request->seqno))
2253 			break;
2254 
2255 		/* We know the GPU must have read the request to have
2256 		 * sent us the seqno + interrupt, so use the position
2257 		 * of tail of the request to update the last known position
2258 		 * of the GPU head.
2259 		 */
2260 		ring->last_retired_head = request->tail;
2261 
2262 		i915_gem_free_request(request);
2263 	}
2264 
2265 	/* Move any buffers on the active list that are no longer referenced
2266 	 * by the ringbuffer to the flushing/inactive lists as appropriate.
2267 	 */
2268 	while (!list_empty(&ring->active_list)) {
2269 		struct drm_i915_gem_object *obj;
2270 
2271 		obj = list_first_entry(&ring->active_list,
2272 				      struct drm_i915_gem_object,
2273 				      ring_list);
2274 
2275 		if (!i915_seqno_passed(seqno, obj->last_read_seqno))
2276 			break;
2277 
2278 		i915_gem_object_move_to_inactive(obj);
2279 	}
2280 
2281 	if (unlikely(ring->trace_irq_seqno &&
2282 		     i915_seqno_passed(seqno, ring->trace_irq_seqno))) {
2283 		ring->irq_put(ring);
2284 		ring->trace_irq_seqno = 0;
2285 	}
2286 
2287 }
2288 
2289 void
2290 i915_gem_retire_requests(struct drm_device *dev)
2291 {
2292 	drm_i915_private_t *dev_priv = dev->dev_private;
2293 	struct intel_ring_buffer *ring;
2294 	int i;
2295 
2296 	for_each_ring(ring, dev_priv, i)
2297 		i915_gem_retire_requests_ring(ring);
2298 }
2299 
2300 static long
2301 __i915_gem_shrink(struct drm_i915_private *dev_priv, long target,
2302 		  bool purgeable_only)
2303 {
2304 	struct drm_i915_gem_object *obj, *next;
2305 	long count = 0;
2306 
2307 	list_for_each_entry_safe(obj, next,
2308 				 &dev_priv->mm.unbound_list,
2309 				 global_list) {
2310 #if 0
2311 		if ((i915_gem_object_is_purgeable(obj) || !purgeable_only) &&
2312 		    i915_gem_object_put_pages(obj) == 0) {
2313 			count += obj->base.size >> PAGE_SHIFT;
2314 			if (count >= target)
2315 				return count;
2316 		}
2317 #endif
2318 	}
2319 
2320 	list_for_each_entry_safe(obj, next,
2321 				 &dev_priv->mm.inactive_list,
2322 				 mm_list) {
2323 #if 0
2324 		if ((i915_gem_object_is_purgeable(obj) || !purgeable_only) &&
2325 		    i915_gem_object_unbind(obj) == 0 &&
2326 		    i915_gem_object_put_pages(obj) == 0) {
2327 			count += obj->base.size >> PAGE_SHIFT;
2328 			if (count >= target)
2329 				return count;
2330 		}
2331 #endif
2332 	}
2333 
2334 	return count;
2335 }
2336 
2337 static long
2338 i915_gem_purge(struct drm_i915_private *dev_priv, long target)
2339 {
2340 	return __i915_gem_shrink(dev_priv, target, true);
2341 }
2342 
2343 static void
2344 i915_gem_retire_work_handler(struct work_struct *work)
2345 {
2346 	drm_i915_private_t *dev_priv;
2347 	struct drm_device *dev;
2348 	struct intel_ring_buffer *ring;
2349 	bool idle;
2350 	int i;
2351 
2352 	dev_priv = container_of(work, drm_i915_private_t,
2353 				mm.retire_work.work);
2354 	dev = dev_priv->dev;
2355 
2356 	/* Come back later if the device is busy... */
2357 	if (lockmgr(&dev->struct_mutex, LK_EXCLUSIVE|LK_NOWAIT)) {
2358 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work,
2359 				   round_jiffies_up_relative(hz));
2360 		return;
2361 	}
2362 
2363 	i915_gem_retire_requests(dev);
2364 
2365 	/* Send a periodic flush down the ring so we don't hold onto GEM
2366 	 * objects indefinitely.
2367 	 */
2368 	idle = true;
2369 	for_each_ring(ring, dev_priv, i) {
2370 		if (ring->gpu_caches_dirty)
2371 			i915_add_request(ring, NULL);
2372 
2373 		idle &= list_empty(&ring->request_list);
2374 	}
2375 
2376 	if (!dev_priv->mm.suspended && !idle)
2377 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work,
2378 				   round_jiffies_up_relative(hz));
2379 	if (idle)
2380 		intel_mark_idle(dev);
2381 
2382 	mutex_unlock(&dev->struct_mutex);
2383 }
2384 /**
2385  * Ensures that an object will eventually get non-busy by flushing any required
2386  * write domains, emitting any outstanding lazy request and retiring and
2387  * completed requests.
2388  */
2389 static int
2390 i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
2391 {
2392 	int ret;
2393 
2394 	if (obj->active) {
2395 		ret = i915_gem_check_olr(obj->ring, obj->last_read_seqno);
2396 		if (ret)
2397 			return ret;
2398 
2399 		i915_gem_retire_requests_ring(obj->ring);
2400 	}
2401 
2402 	return 0;
2403 }
2404 
2405 /**
2406  * i915_gem_wait_ioctl - implements DRM_IOCTL_I915_GEM_WAIT
2407  * @DRM_IOCTL_ARGS: standard ioctl arguments
2408  *
2409  * Returns 0 if successful, else an error is returned with the remaining time in
2410  * the timeout parameter.
2411  *  -ETIME: object is still busy after timeout
2412  *  -ERESTARTSYS: signal interrupted the wait
2413  *  -ENONENT: object doesn't exist
2414  * Also possible, but rare:
2415  *  -EAGAIN: GPU wedged
2416  *  -ENOMEM: damn
2417  *  -ENODEV: Internal IRQ fail
2418  *  -E?: The add request failed
2419  *
2420  * The wait ioctl with a timeout of 0 reimplements the busy ioctl. With any
2421  * non-zero timeout parameter the wait ioctl will wait for the given number of
2422  * nanoseconds on an object becoming unbusy. Since the wait itself does so
2423  * without holding struct_mutex the object may become re-busied before this
2424  * function completes. A similar but shorter * race condition exists in the busy
2425  * ioctl
2426  */
2427 int
2428 i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
2429 {
2430 	drm_i915_private_t *dev_priv = dev->dev_private;
2431 	struct drm_i915_gem_wait *args = data;
2432 	struct drm_i915_gem_object *obj;
2433 	struct intel_ring_buffer *ring = NULL;
2434 	struct timespec timeout_stack, *timeout = NULL;
2435 	unsigned reset_counter;
2436 	u32 seqno = 0;
2437 	int ret = 0;
2438 
2439 	if (args->timeout_ns >= 0) {
2440 		timeout_stack = ns_to_timespec(args->timeout_ns);
2441 		timeout = &timeout_stack;
2442 	}
2443 
2444 	ret = i915_mutex_lock_interruptible(dev);
2445 	if (ret)
2446 		return ret;
2447 
2448 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->bo_handle));
2449 	if (&obj->base == NULL) {
2450 		mutex_unlock(&dev->struct_mutex);
2451 		return -ENOENT;
2452 	}
2453 
2454 	/* Need to make sure the object gets inactive eventually. */
2455 	ret = i915_gem_object_flush_active(obj);
2456 	if (ret)
2457 		goto out;
2458 
2459 	if (obj->active) {
2460 		seqno = obj->last_read_seqno;
2461 		ring = obj->ring;
2462 	}
2463 
2464 	if (seqno == 0)
2465 		 goto out;
2466 
2467 	/* Do this after OLR check to make sure we make forward progress polling
2468 	 * on this IOCTL with a 0 timeout (like busy ioctl)
2469 	 */
2470 	if (!args->timeout_ns) {
2471 		ret = -ETIMEDOUT;
2472 		goto out;
2473 	}
2474 
2475 	drm_gem_object_unreference(&obj->base);
2476 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
2477 	mutex_unlock(&dev->struct_mutex);
2478 
2479 	ret = __wait_seqno(ring, seqno, reset_counter, true, timeout);
2480 	if (timeout)
2481 		args->timeout_ns = timespec_to_ns(timeout);
2482 	return ret;
2483 
2484 out:
2485 	drm_gem_object_unreference(&obj->base);
2486 	mutex_unlock(&dev->struct_mutex);
2487 	return ret;
2488 }
2489 
2490 /**
2491  * i915_gem_object_sync - sync an object to a ring.
2492  *
2493  * @obj: object which may be in use on another ring.
2494  * @to: ring we wish to use the object on. May be NULL.
2495  *
2496  * This code is meant to abstract object synchronization with the GPU.
2497  * Calling with NULL implies synchronizing the object with the CPU
2498  * rather than a particular GPU ring.
2499  *
2500  * Returns 0 if successful, else propagates up the lower layer error.
2501  */
2502 int
2503 i915_gem_object_sync(struct drm_i915_gem_object *obj,
2504 		     struct intel_ring_buffer *to)
2505 {
2506 	struct intel_ring_buffer *from = obj->ring;
2507 	u32 seqno;
2508 	int ret, idx;
2509 
2510 	if (from == NULL || to == from)
2511 		return 0;
2512 
2513 	if (to == NULL || !i915_semaphore_is_enabled(obj->base.dev))
2514 		return i915_gem_object_wait_rendering(obj, false);
2515 
2516 	idx = intel_ring_sync_index(from, to);
2517 
2518 	seqno = obj->last_read_seqno;
2519 	if (seqno <= from->sync_seqno[idx])
2520 		return 0;
2521 
2522 	ret = i915_gem_check_olr(obj->ring, seqno);
2523 	if (ret)
2524 		return ret;
2525 
2526 	ret = to->sync_to(to, from, seqno);
2527 	if (!ret)
2528 		/* We use last_read_seqno because sync_to()
2529 		 * might have just caused seqno wrap under
2530 		 * the radar.
2531 		 */
2532 		from->sync_seqno[idx] = obj->last_read_seqno;
2533 
2534 	return ret;
2535 }
2536 
2537 static void i915_gem_object_finish_gtt(struct drm_i915_gem_object *obj)
2538 {
2539 	u32 old_write_domain, old_read_domains;
2540 
2541 	/* Force a pagefault for domain tracking on next user access */
2542 	i915_gem_release_mmap(obj);
2543 
2544 	if ((obj->base.read_domains & I915_GEM_DOMAIN_GTT) == 0)
2545 		return;
2546 
2547 	/* Wait for any direct GTT access to complete */
2548 	cpu_mfence();
2549 
2550 	old_read_domains = obj->base.read_domains;
2551 	old_write_domain = obj->base.write_domain;
2552 
2553 	obj->base.read_domains &= ~I915_GEM_DOMAIN_GTT;
2554 	obj->base.write_domain &= ~I915_GEM_DOMAIN_GTT;
2555 
2556 }
2557 
2558 /**
2559  * Unbinds an object from the GTT aperture.
2560  */
2561 int
2562 i915_gem_object_unbind(struct drm_i915_gem_object *obj)
2563 {
2564 	drm_i915_private_t *dev_priv = obj->base.dev->dev_private;
2565 	int ret;
2566 
2567 	if (obj->gtt_space == NULL)
2568 		return 0;
2569 
2570 	if (obj->pin_count)
2571 		return -EBUSY;
2572 
2573 	BUG_ON(obj->pages == NULL);
2574 
2575 	ret = i915_gem_object_finish_gpu(obj);
2576 	if (ret)
2577 		return ret;
2578 	/* Continue on if we fail due to EIO, the GPU is hung so we
2579 	 * should be safe and we need to cleanup or else we might
2580 	 * cause memory corruption through use-after-free.
2581 	 */
2582 
2583 	i915_gem_object_finish_gtt(obj);
2584 
2585 	/* Move the object to the CPU domain to ensure that
2586 	 * any possible CPU writes while it's not in the GTT
2587 	 * are flushed when we go to remap it.
2588 	 */
2589 	if (ret == 0)
2590 		ret = i915_gem_object_set_to_cpu_domain(obj, 1);
2591 	if (ret == -ERESTARTSYS)
2592 		return ret;
2593 	if (ret) {
2594 		/* In the event of a disaster, abandon all caches and
2595 		 * hope for the best.
2596 		 */
2597 		i915_gem_clflush_object(obj);
2598 		obj->base.read_domains = obj->base.write_domain = I915_GEM_DOMAIN_CPU;
2599 	}
2600 
2601 	/* release the fence reg _after_ flushing */
2602 	ret = i915_gem_object_put_fence(obj);
2603 	if (ret)
2604 		return ret;
2605 
2606 	if (obj->has_global_gtt_mapping)
2607 		i915_gem_gtt_unbind_object(obj);
2608 	if (obj->has_aliasing_ppgtt_mapping) {
2609 		i915_ppgtt_unbind_object(dev_priv->mm.aliasing_ppgtt, obj);
2610 		obj->has_aliasing_ppgtt_mapping = 0;
2611 	}
2612 	i915_gem_gtt_finish_object(obj);
2613 
2614 	i915_gem_object_put_pages_gtt(obj);
2615 
2616 	list_del_init(&obj->global_list);
2617 	list_del_init(&obj->mm_list);
2618 	/* Avoid an unnecessary call to unbind on rebind. */
2619 	obj->map_and_fenceable = true;
2620 
2621 	drm_mm_put_block(obj->gtt_space);
2622 	obj->gtt_space = NULL;
2623 	obj->gtt_offset = 0;
2624 
2625 	if (i915_gem_object_is_purgeable(obj))
2626 		i915_gem_object_truncate(obj);
2627 
2628 	return ret;
2629 }
2630 
2631 int i915_gpu_idle(struct drm_device *dev)
2632 {
2633 	drm_i915_private_t *dev_priv = dev->dev_private;
2634 	struct intel_ring_buffer *ring;
2635 	int ret, i;
2636 
2637 	/* Flush everything onto the inactive list. */
2638 	for_each_ring(ring, dev_priv, i) {
2639 		ret = i915_switch_context(ring, NULL, DEFAULT_CONTEXT_ID);
2640 		if (ret)
2641 			return ret;
2642 
2643 		ret = intel_ring_idle(ring);
2644 		if (ret)
2645 			return ret;
2646 	}
2647 
2648 	return 0;
2649 }
2650 
2651 static void i965_write_fence_reg(struct drm_device *dev, int reg,
2652 				 struct drm_i915_gem_object *obj)
2653 {
2654 	drm_i915_private_t *dev_priv = dev->dev_private;
2655 	int fence_reg;
2656 	int fence_pitch_shift;
2657 
2658 	if (INTEL_INFO(dev)->gen >= 6) {
2659 		fence_reg = FENCE_REG_SANDYBRIDGE_0;
2660 		fence_pitch_shift = SANDYBRIDGE_FENCE_PITCH_SHIFT;
2661 	} else {
2662 		fence_reg = FENCE_REG_965_0;
2663 		fence_pitch_shift = I965_FENCE_PITCH_SHIFT;
2664 	}
2665 
2666 	fence_reg += reg * 8;
2667 
2668 	/* To w/a incoherency with non-atomic 64-bit register updates,
2669 	 * we split the 64-bit update into two 32-bit writes. In order
2670 	 * for a partial fence not to be evaluated between writes, we
2671 	 * precede the update with write to turn off the fence register,
2672 	 * and only enable the fence as the last step.
2673 	 *
2674 	 * For extra levels of paranoia, we make sure each step lands
2675 	 * before applying the next step.
2676 	 */
2677 	I915_WRITE(fence_reg, 0);
2678 	POSTING_READ(fence_reg);
2679 
2680 	if (obj) {
2681 		u32 size = obj->gtt_space->size;
2682 		uint64_t val;
2683 
2684 		val = (uint64_t)((obj->gtt_offset + size - 4096) &
2685 				 0xfffff000) << 32;
2686 		val |= obj->gtt_offset & 0xfffff000;
2687 		val |= (uint64_t)((obj->stride / 128) - 1) << fence_pitch_shift;
2688 		if (obj->tiling_mode == I915_TILING_Y)
2689 			val |= 1 << I965_FENCE_TILING_Y_SHIFT;
2690 		val |= I965_FENCE_REG_VALID;
2691 
2692 		I915_WRITE(fence_reg + 4, val >> 32);
2693 		POSTING_READ(fence_reg + 4);
2694 
2695 		I915_WRITE(fence_reg + 0, val);
2696 		POSTING_READ(fence_reg);
2697 	} else {
2698 		I915_WRITE(fence_reg + 4, 0);
2699 		POSTING_READ(fence_reg + 4);
2700 	}
2701 }
2702 
2703 static void i915_write_fence_reg(struct drm_device *dev, int reg,
2704 				 struct drm_i915_gem_object *obj)
2705 {
2706 	drm_i915_private_t *dev_priv = dev->dev_private;
2707 	u32 val;
2708 
2709 	if (obj) {
2710 		u32 size = obj->gtt_space->size;
2711 		int pitch_val;
2712 		int tile_width;
2713 
2714 		WARN((obj->gtt_offset & ~I915_FENCE_START_MASK) ||
2715 		     (size & -size) != size ||
2716 		     (obj->gtt_offset & (size - 1)),
2717 		     "object 0x%08x [fenceable? %d] not 1M or pot-size (0x%08x) aligned\n",
2718 		     obj->gtt_offset, obj->map_and_fenceable, size);
2719 
2720 		if (obj->tiling_mode == I915_TILING_Y && HAS_128_BYTE_Y_TILING(dev))
2721 			tile_width = 128;
2722 		else
2723 			tile_width = 512;
2724 
2725 		/* Note: pitch better be a power of two tile widths */
2726 		pitch_val = obj->stride / tile_width;
2727 		pitch_val = ffs(pitch_val) - 1;
2728 
2729 		val = obj->gtt_offset;
2730 		if (obj->tiling_mode == I915_TILING_Y)
2731 			val |= 1 << I830_FENCE_TILING_Y_SHIFT;
2732 		val |= I915_FENCE_SIZE_BITS(size);
2733 		val |= pitch_val << I830_FENCE_PITCH_SHIFT;
2734 		val |= I830_FENCE_REG_VALID;
2735 	} else
2736 		val = 0;
2737 
2738 	if (reg < 8)
2739 		reg = FENCE_REG_830_0 + reg * 4;
2740 	else
2741 		reg = FENCE_REG_945_8 + (reg - 8) * 4;
2742 
2743 	I915_WRITE(reg, val);
2744 	POSTING_READ(reg);
2745 }
2746 
2747 static void i830_write_fence_reg(struct drm_device *dev, int reg,
2748 				struct drm_i915_gem_object *obj)
2749 {
2750 	drm_i915_private_t *dev_priv = dev->dev_private;
2751 	uint32_t val;
2752 
2753 	if (obj) {
2754 		u32 size = obj->gtt_space->size;
2755 		uint32_t pitch_val;
2756 
2757 		WARN((obj->gtt_offset & ~I830_FENCE_START_MASK) ||
2758 		     (size & -size) != size ||
2759 		     (obj->gtt_offset & (size - 1)),
2760 		     "object 0x%08x not 512K or pot-size 0x%08x aligned\n",
2761 		     obj->gtt_offset, size);
2762 
2763 		pitch_val = obj->stride / 128;
2764 		pitch_val = ffs(pitch_val) - 1;
2765 
2766 		val = obj->gtt_offset;
2767 		if (obj->tiling_mode == I915_TILING_Y)
2768 			val |= 1 << I830_FENCE_TILING_Y_SHIFT;
2769 		val |= I830_FENCE_SIZE_BITS(size);
2770 		val |= pitch_val << I830_FENCE_PITCH_SHIFT;
2771 		val |= I830_FENCE_REG_VALID;
2772 	} else
2773 		val = 0;
2774 
2775 	I915_WRITE(FENCE_REG_830_0 + reg * 4, val);
2776 	POSTING_READ(FENCE_REG_830_0 + reg * 4);
2777 }
2778 
2779 inline static bool i915_gem_object_needs_mb(struct drm_i915_gem_object *obj)
2780 {
2781 	return obj && obj->base.read_domains & I915_GEM_DOMAIN_GTT;
2782 }
2783 
2784 static void i915_gem_write_fence(struct drm_device *dev, int reg,
2785 				 struct drm_i915_gem_object *obj)
2786 {
2787 	struct drm_i915_private *dev_priv = dev->dev_private;
2788 
2789 	/* Ensure that all CPU reads are completed before installing a fence
2790 	 * and all writes before removing the fence.
2791 	 */
2792 	if (i915_gem_object_needs_mb(dev_priv->fence_regs[reg].obj))
2793 		cpu_mfence();
2794 
2795 	WARN(obj && (!obj->stride || !obj->tiling_mode),
2796 	     "bogus fence setup with stride: 0x%x, tiling mode: %i\n",
2797 	     obj->stride, obj->tiling_mode);
2798 
2799 	switch (INTEL_INFO(dev)->gen) {
2800 	case 7:
2801 	case 6:
2802 	case 5:
2803 	case 4: i965_write_fence_reg(dev, reg, obj); break;
2804 	case 3: i915_write_fence_reg(dev, reg, obj); break;
2805 	case 2: i830_write_fence_reg(dev, reg, obj); break;
2806 	default: BUG();
2807 	}
2808 
2809 	/* And similarly be paranoid that no direct access to this region
2810 	 * is reordered to before the fence is installed.
2811 	 */
2812 	if (i915_gem_object_needs_mb(obj))
2813 		cpu_mfence();
2814 }
2815 
2816 static inline int fence_number(struct drm_i915_private *dev_priv,
2817 			       struct drm_i915_fence_reg *fence)
2818 {
2819 	return fence - dev_priv->fence_regs;
2820 }
2821 
2822 static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
2823 					 struct drm_i915_fence_reg *fence,
2824 					 bool enable)
2825 {
2826 	struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
2827 	int reg = fence_number(dev_priv, fence);
2828 
2829 	i915_gem_write_fence(obj->base.dev, reg, enable ? obj : NULL);
2830 
2831 	if (enable) {
2832 		obj->fence_reg = reg;
2833 		fence->obj = obj;
2834 		list_move_tail(&fence->lru_list, &dev_priv->mm.fence_list);
2835 	} else {
2836 		obj->fence_reg = I915_FENCE_REG_NONE;
2837 		fence->obj = NULL;
2838 		list_del_init(&fence->lru_list);
2839 	}
2840 	obj->fence_dirty = false;
2841 }
2842 
2843 static int
2844 i915_gem_object_wait_fence(struct drm_i915_gem_object *obj)
2845 {
2846 	if (obj->last_fenced_seqno) {
2847 		int ret = i915_wait_seqno(obj->ring, obj->last_fenced_seqno);
2848 		if (ret)
2849 			return ret;
2850 
2851 		obj->last_fenced_seqno = 0;
2852 	}
2853 
2854 	obj->fenced_gpu_access = false;
2855 	return 0;
2856 }
2857 
2858 int
2859 i915_gem_object_put_fence(struct drm_i915_gem_object *obj)
2860 {
2861 	struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
2862 	struct drm_i915_fence_reg *fence;
2863 	int ret;
2864 
2865 	ret = i915_gem_object_wait_fence(obj);
2866 	if (ret)
2867 		return ret;
2868 
2869 	if (obj->fence_reg == I915_FENCE_REG_NONE)
2870 		return 0;
2871 
2872 	fence = &dev_priv->fence_regs[obj->fence_reg];
2873 
2874 	i915_gem_object_fence_lost(obj);
2875 	i915_gem_object_update_fence(obj, fence, false);
2876 
2877 	return 0;
2878 }
2879 
2880 static struct drm_i915_fence_reg *
2881 i915_find_fence_reg(struct drm_device *dev)
2882 {
2883 	struct drm_i915_private *dev_priv = dev->dev_private;
2884 	struct drm_i915_fence_reg *reg, *avail;
2885 	int i;
2886 
2887 	/* First try to find a free reg */
2888 	avail = NULL;
2889 	for (i = dev_priv->fence_reg_start; i < dev_priv->num_fence_regs; i++) {
2890 		reg = &dev_priv->fence_regs[i];
2891 		if (!reg->obj)
2892 			return reg;
2893 
2894 		if (!reg->pin_count)
2895 			avail = reg;
2896 	}
2897 
2898 	if (avail == NULL)
2899 		return NULL;
2900 
2901 	/* None available, try to steal one or wait for a user to finish */
2902 	list_for_each_entry(reg, &dev_priv->mm.fence_list, lru_list) {
2903 		if (reg->pin_count)
2904 			continue;
2905 
2906 		return reg;
2907 	}
2908 
2909 	return NULL;
2910 }
2911 
2912 /**
2913  * i915_gem_object_get_fence - set up fencing for an object
2914  * @obj: object to map through a fence reg
2915  *
2916  * When mapping objects through the GTT, userspace wants to be able to write
2917  * to them without having to worry about swizzling if the object is tiled.
2918  * This function walks the fence regs looking for a free one for @obj,
2919  * stealing one if it can't find any.
2920  *
2921  * It then sets up the reg based on the object's properties: address, pitch
2922  * and tiling format.
2923  *
2924  * For an untiled surface, this removes any existing fence.
2925  */
2926 int
2927 i915_gem_object_get_fence(struct drm_i915_gem_object *obj)
2928 {
2929 	struct drm_device *dev = obj->base.dev;
2930 	struct drm_i915_private *dev_priv = dev->dev_private;
2931 	bool enable = obj->tiling_mode != I915_TILING_NONE;
2932 	struct drm_i915_fence_reg *reg;
2933 	int ret;
2934 
2935 	/* Have we updated the tiling parameters upon the object and so
2936 	 * will need to serialise the write to the associated fence register?
2937 	 */
2938 	if (obj->fence_dirty) {
2939 		ret = i915_gem_object_wait_fence(obj);
2940 		if (ret)
2941 			return ret;
2942 	}
2943 
2944 	/* Just update our place in the LRU if our fence is getting reused. */
2945 	if (obj->fence_reg != I915_FENCE_REG_NONE) {
2946 		reg = &dev_priv->fence_regs[obj->fence_reg];
2947 		if (!obj->fence_dirty) {
2948 			list_move_tail(&reg->lru_list,
2949 				       &dev_priv->mm.fence_list);
2950 			return 0;
2951 		}
2952 	} else if (enable) {
2953 		reg = i915_find_fence_reg(dev);
2954 		if (reg == NULL)
2955 			return -EDEADLK;
2956 
2957 		if (reg->obj) {
2958 			struct drm_i915_gem_object *old = reg->obj;
2959 
2960 			ret = i915_gem_object_wait_fence(old);
2961 			if (ret)
2962 				return ret;
2963 
2964 			i915_gem_object_fence_lost(old);
2965 		}
2966 	} else
2967 		return 0;
2968 
2969 	i915_gem_object_update_fence(obj, reg, enable);
2970 
2971 	return 0;
2972 }
2973 
2974 static bool i915_gem_valid_gtt_space(struct drm_device *dev,
2975 				     struct drm_mm_node *gtt_space,
2976 				     unsigned long cache_level)
2977 {
2978 	struct drm_mm_node *other;
2979 
2980 	/* On non-LLC machines we have to be careful when putting differing
2981 	 * types of snoopable memory together to avoid the prefetcher
2982 	 * crossing memory domains and dying.
2983 	 */
2984 	if (HAS_LLC(dev))
2985 		return true;
2986 
2987 	if (gtt_space == NULL)
2988 		return true;
2989 
2990 	if (list_empty(&gtt_space->node_list))
2991 		return true;
2992 
2993 	other = list_entry(gtt_space->node_list.prev, struct drm_mm_node, node_list);
2994 	if (other->allocated && !other->hole_follows && other->color != cache_level)
2995 		return false;
2996 
2997 	other = list_entry(gtt_space->node_list.next, struct drm_mm_node, node_list);
2998 	if (other->allocated && !gtt_space->hole_follows && other->color != cache_level)
2999 		return false;
3000 
3001 	return true;
3002 }
3003 
3004 static void i915_gem_verify_gtt(struct drm_device *dev)
3005 {
3006 #if WATCH_GTT
3007 	struct drm_i915_private *dev_priv = dev->dev_private;
3008 	struct drm_i915_gem_object *obj;
3009 	int err = 0;
3010 
3011 	list_for_each_entry(obj, &dev_priv->mm.global_list, global_list) {
3012 		if (obj->gtt_space == NULL) {
3013 			printk(KERN_ERR "object found on GTT list with no space reserved\n");
3014 			err++;
3015 			continue;
3016 		}
3017 
3018 		if (obj->cache_level != obj->gtt_space->color) {
3019 			printk(KERN_ERR "object reserved space [%08lx, %08lx] with wrong color, cache_level=%x, color=%lx\n",
3020 			       obj->gtt_space->start,
3021 			       obj->gtt_space->start + obj->gtt_space->size,
3022 			       obj->cache_level,
3023 			       obj->gtt_space->color);
3024 			err++;
3025 			continue;
3026 		}
3027 
3028 		if (!i915_gem_valid_gtt_space(dev,
3029 					      obj->gtt_space,
3030 					      obj->cache_level)) {
3031 			printk(KERN_ERR "invalid GTT space found at [%08lx, %08lx] - color=%x\n",
3032 			       obj->gtt_space->start,
3033 			       obj->gtt_space->start + obj->gtt_space->size,
3034 			       obj->cache_level);
3035 			err++;
3036 			continue;
3037 		}
3038 	}
3039 
3040 	WARN_ON(err);
3041 #endif
3042 }
3043 
3044 /**
3045  * Finds free space in the GTT aperture and binds the object there.
3046  */
3047 static int
3048 i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
3049 			    unsigned alignment,
3050 			    bool map_and_fenceable,
3051 			    bool nonblocking)
3052 {
3053 	struct drm_device *dev = obj->base.dev;
3054 	drm_i915_private_t *dev_priv = dev->dev_private;
3055 	struct drm_mm_node *node;
3056 	u32 size, fence_size, fence_alignment, unfenced_alignment;
3057 	bool mappable, fenceable;
3058 	size_t gtt_max = map_and_fenceable ?
3059 		dev_priv->gtt.mappable_end : dev_priv->gtt.total;
3060 	int ret;
3061 
3062 	fence_size = i915_gem_get_gtt_size(dev,
3063 					   obj->base.size,
3064 					   obj->tiling_mode);
3065 	fence_alignment = i915_gem_get_gtt_alignment(dev,
3066 						     obj->base.size,
3067 						     obj->tiling_mode, true);
3068 	unfenced_alignment =
3069 		i915_gem_get_gtt_alignment(dev,
3070 						    obj->base.size,
3071 						    obj->tiling_mode, false);
3072 
3073 	if (alignment == 0)
3074 		alignment = map_and_fenceable ? fence_alignment :
3075 						unfenced_alignment;
3076 	if (map_and_fenceable && alignment & (fence_alignment - 1)) {
3077 		DRM_ERROR("Invalid object alignment requested %u\n", alignment);
3078 		return -EINVAL;
3079 	}
3080 
3081 	size = map_and_fenceable ? fence_size : obj->base.size;
3082 
3083 	/* If the object is bigger than the entire aperture, reject it early
3084 	 * before evicting everything in a vain attempt to find space.
3085 	 */
3086 	if (obj->base.size > gtt_max) {
3087 		DRM_ERROR("Attempting to bind an object larger than the aperture: object=%zd > %s aperture=%zu\n",
3088 			  obj->base.size,
3089 			  map_and_fenceable ? "mappable" : "total",
3090 			  gtt_max);
3091 		return -E2BIG;
3092 	}
3093 
3094  search_free:
3095 	if (map_and_fenceable)
3096 		node = drm_mm_search_free_in_range_color(&dev_priv->mm.gtt_space,
3097 							  size, alignment, obj->cache_level,
3098 							  0, dev_priv->gtt.mappable_end,
3099 							  false);
3100 	else
3101 		node = drm_mm_search_free_color(&dev_priv->mm.gtt_space,
3102 						      size, alignment, obj->cache_level,
3103 						      false);
3104 	if (node != NULL) {
3105 		if (map_and_fenceable)
3106 			obj->gtt_space =
3107 				drm_mm_get_block_range_generic(node,
3108 							       size, alignment, obj->cache_level,
3109 							       0, dev_priv->gtt.mappable_end,
3110 							       false);
3111 		else
3112 			obj->gtt_space =
3113 				drm_mm_get_block_generic(node,
3114 							 size, alignment, obj->cache_level,
3115 							 false);
3116 	}
3117 	if (obj->gtt_space == NULL) {
3118 		ret = i915_gem_evict_something(dev, size, alignment,
3119 					       obj->cache_level,
3120 					       map_and_fenceable,
3121 					       nonblocking);
3122 		if (ret)
3123 			return ret;
3124 
3125 		goto search_free;
3126 	}
3127 
3128 	/*
3129 	 * NOTE: i915_gem_object_get_pages_gtt() cannot
3130 	 *	 return ENOMEM, since we used VM_ALLOC_RETRY.
3131 	 */
3132 	ret = i915_gem_object_get_pages_gtt(obj);
3133 	if (ret != 0) {
3134 		drm_mm_put_block(obj->gtt_space);
3135 		obj->gtt_space = NULL;
3136 		return ret;
3137 	}
3138 
3139 	i915_gem_gtt_bind_object(obj, obj->cache_level);
3140 	if (ret != 0) {
3141 		i915_gem_object_put_pages_gtt(obj);
3142 		drm_mm_put_block(obj->gtt_space);
3143 		obj->gtt_space = NULL;
3144 		if (i915_gem_evict_everything(dev))
3145 			return (ret);
3146 		goto search_free;
3147 	}
3148 
3149 	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
3150 	list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
3151 
3152 	obj->gtt_offset = obj->gtt_space->start;
3153 
3154 	fenceable =
3155 		obj->gtt_space->size == fence_size &&
3156 		(obj->gtt_space->start & (fence_alignment - 1)) == 0;
3157 
3158 	mappable =
3159 		obj->gtt_offset + obj->base.size <= dev_priv->gtt.mappable_end;
3160 
3161 	obj->map_and_fenceable = mappable && fenceable;
3162 
3163 	trace_i915_gem_object_bind(obj, map_and_fenceable);
3164 	i915_gem_verify_gtt(dev);
3165 	return 0;
3166 }
3167 
3168 void
3169 i915_gem_clflush_object(struct drm_i915_gem_object *obj)
3170 {
3171 
3172 	/* If we don't have a page list set up, then we're not pinned
3173 	 * to GPU, and we can ignore the cache flush because it'll happen
3174 	 * again at bind time.
3175 	 */
3176 	if (obj->pages == NULL)
3177 		return;
3178 
3179 	/*
3180 	 * Stolen memory is always coherent with the GPU as it is explicitly
3181 	 * marked as wc by the system, or the system is cache-coherent.
3182 	 */
3183 	if (obj->stolen)
3184 		return;
3185 
3186 	/* If the GPU is snooping the contents of the CPU cache,
3187 	 * we do not need to manually clear the CPU cache lines.  However,
3188 	 * the caches are only snooped when the render cache is
3189 	 * flushed/invalidated.  As we always have to emit invalidations
3190 	 * and flushes when moving into and out of the RENDER domain, correct
3191 	 * snooping behaviour occurs naturally as the result of our domain
3192 	 * tracking.
3193 	 */
3194 	if (obj->cache_level != I915_CACHE_NONE)
3195 		return;
3196 
3197 	drm_clflush_pages(obj->pages, obj->base.size / PAGE_SIZE);
3198 }
3199 
3200 /** Flushes the GTT write domain for the object if it's dirty. */
3201 static void
3202 i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj)
3203 {
3204 	uint32_t old_write_domain;
3205 
3206 	if (obj->base.write_domain != I915_GEM_DOMAIN_GTT)
3207 		return;
3208 
3209 	/* No actual flushing is required for the GTT write domain.  Writes
3210 	 * to it immediately go to main memory as far as we know, so there's
3211 	 * no chipset flush.  It also doesn't land in render cache.
3212 	 *
3213 	 * However, we do have to enforce the order so that all writes through
3214 	 * the GTT land before any writes to the device, such as updates to
3215 	 * the GATT itself.
3216 	 */
3217 	cpu_sfence();
3218 
3219 	old_write_domain = obj->base.write_domain;
3220 	obj->base.write_domain = 0;
3221 }
3222 
3223 /** Flushes the CPU write domain for the object if it's dirty. */
3224 static void
3225 i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj)
3226 {
3227 	uint32_t old_write_domain;
3228 
3229 	if (obj->base.write_domain != I915_GEM_DOMAIN_CPU)
3230 		return;
3231 
3232 	i915_gem_clflush_object(obj);
3233 	i915_gem_chipset_flush(obj->base.dev);
3234 	old_write_domain = obj->base.write_domain;
3235 	obj->base.write_domain = 0;
3236 }
3237 
3238 /**
3239  * Moves a single object to the GTT read, and possibly write domain.
3240  *
3241  * This function returns when the move is complete, including waiting on
3242  * flushes to occur.
3243  */
3244 int
3245 i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
3246 {
3247 	drm_i915_private_t *dev_priv = obj->base.dev->dev_private;
3248 	uint32_t old_write_domain, old_read_domains;
3249 	int ret;
3250 
3251 	/* Not valid to be called on unbound objects. */
3252 	if (obj->gtt_space == NULL)
3253 		return -EINVAL;
3254 
3255 	if (obj->base.write_domain == I915_GEM_DOMAIN_GTT)
3256 		return 0;
3257 
3258 	ret = i915_gem_object_wait_rendering(obj, !write);
3259 	if (ret)
3260 		return ret;
3261 
3262 	i915_gem_object_flush_cpu_write_domain(obj);
3263 
3264 	/* Serialise direct access to this object with the barriers for
3265 	 * coherent writes from the GPU, by effectively invalidating the
3266 	 * GTT domain upon first access.
3267 	 */
3268 	if ((obj->base.read_domains & I915_GEM_DOMAIN_GTT) == 0)
3269 		cpu_mfence();
3270 
3271 	old_write_domain = obj->base.write_domain;
3272 	old_read_domains = obj->base.read_domains;
3273 
3274 	/* It should now be out of any other write domains, and we can update
3275 	 * the domain values for our changes.
3276 	 */
3277 	BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_GTT) != 0);
3278 	obj->base.read_domains |= I915_GEM_DOMAIN_GTT;
3279 	if (write) {
3280 		obj->base.read_domains = I915_GEM_DOMAIN_GTT;
3281 		obj->base.write_domain = I915_GEM_DOMAIN_GTT;
3282 		obj->dirty = 1;
3283 	}
3284 
3285 	/* And bump the LRU for this access */
3286 	if (i915_gem_object_is_inactive(obj))
3287 		list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
3288 
3289 	return 0;
3290 }
3291 
3292 int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
3293 				    enum i915_cache_level cache_level)
3294 {
3295 	struct drm_device *dev = obj->base.dev;
3296 	drm_i915_private_t *dev_priv = dev->dev_private;
3297 	int ret;
3298 
3299 	if (obj->cache_level == cache_level)
3300 		return 0;
3301 
3302 	if (obj->pin_count) {
3303 		DRM_DEBUG("can not change the cache level of pinned objects\n");
3304 		return -EBUSY;
3305 	}
3306 
3307 	if (!i915_gem_valid_gtt_space(dev, obj->gtt_space, cache_level)) {
3308 		ret = i915_gem_object_unbind(obj);
3309 		if (ret)
3310 			return ret;
3311 	}
3312 
3313 	if (obj->gtt_space) {
3314 		ret = i915_gem_object_finish_gpu(obj);
3315 		if (ret)
3316 			return ret;
3317 
3318 		i915_gem_object_finish_gtt(obj);
3319 
3320 		/* Before SandyBridge, you could not use tiling or fence
3321 		 * registers with snooped memory, so relinquish any fences
3322 		 * currently pointing to our region in the aperture.
3323 		 */
3324 		if (INTEL_INFO(dev)->gen < 6) {
3325 			ret = i915_gem_object_put_fence(obj);
3326 			if (ret)
3327 				return ret;
3328 		}
3329 
3330 		if (obj->has_global_gtt_mapping)
3331 			i915_gem_gtt_bind_object(obj, cache_level);
3332 		if (obj->has_aliasing_ppgtt_mapping)
3333 			i915_ppgtt_bind_object(dev_priv->mm.aliasing_ppgtt,
3334 					       obj, cache_level);
3335 
3336 		obj->gtt_space->color = cache_level;
3337 	}
3338 
3339 	if (cache_level == I915_CACHE_NONE) {
3340 		u32 old_read_domains, old_write_domain;
3341 
3342 		/* If we're coming from LLC cached, then we haven't
3343 		 * actually been tracking whether the data is in the
3344 		 * CPU cache or not, since we only allow one bit set
3345 		 * in obj->write_domain and have been skipping the clflushes.
3346 		 * Just set it to the CPU cache for now.
3347 		 */
3348 		WARN_ON(obj->base.write_domain & ~I915_GEM_DOMAIN_CPU);
3349 		WARN_ON(obj->base.read_domains & ~I915_GEM_DOMAIN_CPU);
3350 
3351 		old_read_domains = obj->base.read_domains;
3352 		old_write_domain = obj->base.write_domain;
3353 
3354 		obj->base.read_domains = I915_GEM_DOMAIN_CPU;
3355 		obj->base.write_domain = I915_GEM_DOMAIN_CPU;
3356 
3357 	}
3358 
3359 	obj->cache_level = cache_level;
3360 	i915_gem_verify_gtt(dev);
3361 	return 0;
3362 }
3363 
3364 int i915_gem_get_caching_ioctl(struct drm_device *dev, void *data,
3365 			       struct drm_file *file)
3366 {
3367 	struct drm_i915_gem_caching *args = data;
3368 	struct drm_i915_gem_object *obj;
3369 	int ret;
3370 
3371 	ret = i915_mutex_lock_interruptible(dev);
3372 	if (ret)
3373 		return ret;
3374 
3375 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
3376 	if (&obj->base == NULL) {
3377 		ret = -ENOENT;
3378 		goto unlock;
3379 	}
3380 
3381 	args->caching = obj->cache_level != I915_CACHE_NONE;
3382 
3383 	drm_gem_object_unreference(&obj->base);
3384 unlock:
3385 	mutex_unlock(&dev->struct_mutex);
3386 	return ret;
3387 }
3388 
3389 int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data,
3390 			       struct drm_file *file)
3391 {
3392 	struct drm_i915_gem_caching *args = data;
3393 	struct drm_i915_gem_object *obj;
3394 	enum i915_cache_level level;
3395 	int ret;
3396 
3397 	switch (args->caching) {
3398 	case I915_CACHING_NONE:
3399 		level = I915_CACHE_NONE;
3400 		break;
3401 	case I915_CACHING_CACHED:
3402 		level = I915_CACHE_LLC;
3403 		break;
3404 	default:
3405 		return -EINVAL;
3406 	}
3407 
3408 	ret = i915_mutex_lock_interruptible(dev);
3409 	if (ret)
3410 		return ret;
3411 
3412 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
3413 	if (&obj->base == NULL) {
3414 		ret = -ENOENT;
3415 		goto unlock;
3416 	}
3417 
3418 	ret = i915_gem_object_set_cache_level(obj, level);
3419 
3420 	drm_gem_object_unreference(&obj->base);
3421 unlock:
3422 	mutex_unlock(&dev->struct_mutex);
3423 	return ret;
3424 }
3425 
3426 /*
3427  * Prepare buffer for display plane (scanout, cursors, etc).
3428  * Can be called from an uninterruptible phase (modesetting) and allows
3429  * any flushes to be pipelined (for pageflips).
3430  */
3431 int
3432 i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
3433 				     u32 alignment,
3434 				     struct intel_ring_buffer *pipelined)
3435 {
3436 	u32 old_read_domains, old_write_domain;
3437 	int ret;
3438 
3439 	if (pipelined != obj->ring) {
3440 		ret = i915_gem_object_sync(obj, pipelined);
3441 		if (ret)
3442 			return ret;
3443 	}
3444 
3445 	/* The display engine is not coherent with the LLC cache on gen6.  As
3446 	 * a result, we make sure that the pinning that is about to occur is
3447 	 * done with uncached PTEs. This is lowest common denominator for all
3448 	 * chipsets.
3449 	 *
3450 	 * However for gen6+, we could do better by using the GFDT bit instead
3451 	 * of uncaching, which would allow us to flush all the LLC-cached data
3452 	 * with that bit in the PTE to main memory with just one PIPE_CONTROL.
3453 	 */
3454 	ret = i915_gem_object_set_cache_level(obj, I915_CACHE_NONE);
3455 	if (ret)
3456 		return ret;
3457 
3458 	/* As the user may map the buffer once pinned in the display plane
3459 	 * (e.g. libkms for the bootup splash), we have to ensure that we
3460 	 * always use map_and_fenceable for all scanout buffers.
3461 	 */
3462 	ret = i915_gem_object_pin(obj, alignment, true, false);
3463 	if (ret)
3464 		return ret;
3465 
3466 	i915_gem_object_flush_cpu_write_domain(obj);
3467 
3468 	old_write_domain = obj->base.write_domain;
3469 	old_read_domains = obj->base.read_domains;
3470 
3471 	/* It should now be out of any other write domains, and we can update
3472 	 * the domain values for our changes.
3473 	 */
3474 	obj->base.write_domain = 0;
3475 	obj->base.read_domains |= I915_GEM_DOMAIN_GTT;
3476 
3477 	return 0;
3478 }
3479 
3480 int
3481 i915_gem_object_finish_gpu(struct drm_i915_gem_object *obj)
3482 {
3483 	int ret;
3484 
3485 	if ((obj->base.read_domains & I915_GEM_GPU_DOMAINS) == 0)
3486 		return 0;
3487 
3488 	ret = i915_gem_object_wait_rendering(obj, false);
3489 	if (ret)
3490 		return ret;
3491 
3492 	/* Ensure that we invalidate the GPU's caches and TLBs. */
3493 	obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
3494 	return 0;
3495 }
3496 
3497 /**
3498  * Moves a single object to the CPU read, and possibly write domain.
3499  *
3500  * This function returns when the move is complete, including waiting on
3501  * flushes to occur.
3502  */
3503 int
3504 i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write)
3505 {
3506 	uint32_t old_write_domain, old_read_domains;
3507 	int ret;
3508 
3509 	if (obj->base.write_domain == I915_GEM_DOMAIN_CPU)
3510 		return 0;
3511 
3512 	ret = i915_gem_object_wait_rendering(obj, !write);
3513 	if (ret)
3514 		return ret;
3515 
3516 	i915_gem_object_flush_gtt_write_domain(obj);
3517 
3518 	old_write_domain = obj->base.write_domain;
3519 	old_read_domains = obj->base.read_domains;
3520 
3521 	/* Flush the CPU cache if it's still invalid. */
3522 	if ((obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0) {
3523 		i915_gem_clflush_object(obj);
3524 
3525 		obj->base.read_domains |= I915_GEM_DOMAIN_CPU;
3526 	}
3527 
3528 	/* It should now be out of any other write domains, and we can update
3529 	 * the domain values for our changes.
3530 	 */
3531 	BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_CPU) != 0);
3532 
3533 	/* If we're writing through the CPU, then the GPU read domains will
3534 	 * need to be invalidated at next use.
3535 	 */
3536 	if (write) {
3537 		obj->base.read_domains = I915_GEM_DOMAIN_CPU;
3538 		obj->base.write_domain = I915_GEM_DOMAIN_CPU;
3539 	}
3540 
3541 	return 0;
3542 }
3543 
3544 /* Throttle our rendering by waiting until the ring has completed our requests
3545  * emitted over 20 msec ago.
3546  *
3547  * Note that if we were to use the current jiffies each time around the loop,
3548  * we wouldn't escape the function with any frames outstanding if the time to
3549  * render a frame was over 20ms.
3550  *
3551  * This should get us reasonable parallelism between CPU and GPU but also
3552  * relatively low latency when blocking on a particular request to finish.
3553  */
3554 static int
3555 i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
3556 {
3557 	struct drm_i915_private *dev_priv = dev->dev_private;
3558 	struct drm_i915_file_private *file_priv = file->driver_priv;
3559 	unsigned long recent_enough = jiffies - msecs_to_jiffies(20);
3560 	struct drm_i915_gem_request *request;
3561 	struct intel_ring_buffer *ring = NULL;
3562 	unsigned reset_counter;
3563 	u32 seqno = 0;
3564 	int ret;
3565 
3566 	ret = i915_gem_wait_for_error(&dev_priv->gpu_error);
3567 	if (ret)
3568 		return ret;
3569 
3570 	ret = i915_gem_check_wedge(&dev_priv->gpu_error, false);
3571 	if (ret)
3572 		return ret;
3573 
3574 	spin_lock(&file_priv->mm.lock);
3575 	list_for_each_entry(request, &file_priv->mm.request_list, client_list) {
3576 		if (time_after_eq(request->emitted_jiffies, recent_enough))
3577 			break;
3578 
3579 		ring = request->ring;
3580 		seqno = request->seqno;
3581 	}
3582 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
3583 	spin_unlock(&file_priv->mm.lock);
3584 
3585 	if (seqno == 0)
3586 		return 0;
3587 
3588 	ret = __wait_seqno(ring, seqno, reset_counter, true, NULL);
3589 	if (ret == 0)
3590 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, 0);
3591 
3592 	return ret;
3593 }
3594 
3595 int
3596 i915_gem_object_pin(struct drm_i915_gem_object *obj,
3597 		    uint32_t alignment,
3598 		    bool map_and_fenceable,
3599 		    bool nonblocking)
3600 {
3601 	int ret;
3602 
3603 	if (WARN_ON(obj->pin_count == DRM_I915_GEM_OBJECT_MAX_PIN_COUNT))
3604 		return -EBUSY;
3605 
3606 	if (obj->gtt_space != NULL) {
3607 		if ((alignment && obj->gtt_offset & (alignment - 1)) ||
3608 		    (map_and_fenceable && !obj->map_and_fenceable)) {
3609 			WARN(obj->pin_count,
3610 			     "bo is already pinned with incorrect alignment:"
3611 			     " offset=%x, req.alignment=%x, req.map_and_fenceable=%d,"
3612 			     " obj->map_and_fenceable=%d\n",
3613 			     obj->gtt_offset, alignment,
3614 			     map_and_fenceable,
3615 			     obj->map_and_fenceable);
3616 			ret = i915_gem_object_unbind(obj);
3617 			if (ret)
3618 				return ret;
3619 		}
3620 	}
3621 
3622 	if (obj->gtt_space == NULL) {
3623 		struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
3624 
3625 		ret = i915_gem_object_bind_to_gtt(obj, alignment,
3626 						  map_and_fenceable,
3627 						  nonblocking);
3628 		if (ret)
3629 			return ret;
3630 
3631 		if (!dev_priv->mm.aliasing_ppgtt)
3632 			i915_gem_gtt_bind_object(obj, obj->cache_level);
3633 	}
3634 
3635 	if (!obj->has_global_gtt_mapping && map_and_fenceable)
3636 		i915_gem_gtt_bind_object(obj, obj->cache_level);
3637 
3638 	obj->pin_count++;
3639 	obj->pin_mappable |= map_and_fenceable;
3640 
3641 	return 0;
3642 }
3643 
3644 void
3645 i915_gem_object_unpin(struct drm_i915_gem_object *obj)
3646 {
3647 	BUG_ON(obj->pin_count == 0);
3648 	BUG_ON(obj->gtt_space == NULL);
3649 
3650 	if (--obj->pin_count == 0)
3651 		obj->pin_mappable = false;
3652 }
3653 
3654 int
3655 i915_gem_pin_ioctl(struct drm_device *dev, void *data,
3656 		   struct drm_file *file)
3657 {
3658 	struct drm_i915_gem_pin *args = data;
3659 	struct drm_i915_gem_object *obj;
3660 	int ret;
3661 
3662 	ret = i915_mutex_lock_interruptible(dev);
3663 	if (ret)
3664 		return ret;
3665 
3666 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
3667 	if (&obj->base == NULL) {
3668 		ret = -ENOENT;
3669 		goto unlock;
3670 	}
3671 
3672 	if (obj->madv != I915_MADV_WILLNEED) {
3673 		DRM_ERROR("Attempting to pin a purgeable buffer\n");
3674 		ret = -EINVAL;
3675 		goto out;
3676 	}
3677 
3678 	if (obj->pin_filp != NULL && obj->pin_filp != file) {
3679 		DRM_ERROR("Already pinned in i915_gem_pin_ioctl(): %d\n",
3680 			  args->handle);
3681 		ret = -EINVAL;
3682 		goto out;
3683 	}
3684 
3685 	if (obj->user_pin_count == 0) {
3686 		ret = i915_gem_object_pin(obj, args->alignment, true, false);
3687 		if (ret)
3688 			goto out;
3689 	}
3690 
3691 	obj->user_pin_count++;
3692 	obj->pin_filp = file;
3693 
3694 	/* XXX - flush the CPU caches for pinned objects
3695 	 * as the X server doesn't manage domains yet
3696 	 */
3697 	i915_gem_object_flush_cpu_write_domain(obj);
3698 	args->offset = obj->gtt_offset;
3699 out:
3700 	drm_gem_object_unreference(&obj->base);
3701 unlock:
3702 	mutex_unlock(&dev->struct_mutex);
3703 	return ret;
3704 }
3705 
3706 int
3707 i915_gem_unpin_ioctl(struct drm_device *dev, void *data,
3708 		     struct drm_file *file)
3709 {
3710 	struct drm_i915_gem_pin *args = data;
3711 	struct drm_i915_gem_object *obj;
3712 	int ret;
3713 
3714 	ret = i915_mutex_lock_interruptible(dev);
3715 	if (ret)
3716 		return ret;
3717 
3718 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
3719 	if (&obj->base == NULL) {
3720 		ret = -ENOENT;
3721 		goto unlock;
3722 	}
3723 
3724 	if (obj->pin_filp != file) {
3725 		DRM_ERROR("Not pinned by caller in i915_gem_pin_ioctl(): %d\n",
3726 			  args->handle);
3727 		ret = -EINVAL;
3728 		goto out;
3729 	}
3730 	obj->user_pin_count--;
3731 	if (obj->user_pin_count == 0) {
3732 		obj->pin_filp = NULL;
3733 		i915_gem_object_unpin(obj);
3734 	}
3735 
3736 out:
3737 	drm_gem_object_unreference(&obj->base);
3738 unlock:
3739 	mutex_unlock(&dev->struct_mutex);
3740 	return ret;
3741 }
3742 
3743 int
3744 i915_gem_busy_ioctl(struct drm_device *dev, void *data,
3745 		    struct drm_file *file)
3746 {
3747 	struct drm_i915_gem_busy *args = data;
3748 	struct drm_i915_gem_object *obj;
3749 	int ret;
3750 
3751 	ret = i915_mutex_lock_interruptible(dev);
3752 	if (ret)
3753 		return ret;
3754 
3755 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
3756 	if (&obj->base == NULL) {
3757 		ret = -ENOENT;
3758 		goto unlock;
3759 	}
3760 
3761 	/* Count all active objects as busy, even if they are currently not used
3762 	 * by the gpu. Users of this interface expect objects to eventually
3763 	 * become non-busy without any further actions, therefore emit any
3764 	 * necessary flushes here.
3765 	 */
3766 	ret = i915_gem_object_flush_active(obj);
3767 
3768 	args->busy = obj->active;
3769 	if (obj->ring) {
3770 		args->busy |= intel_ring_flag(obj->ring) << 16;
3771 	}
3772 
3773 	drm_gem_object_unreference(&obj->base);
3774 unlock:
3775 	mutex_unlock(&dev->struct_mutex);
3776 	return ret;
3777 }
3778 
3779 int
3780 i915_gem_throttle_ioctl(struct drm_device *dev, void *data,
3781 			struct drm_file *file_priv)
3782 {
3783 	return i915_gem_ring_throttle(dev, file_priv);
3784 }
3785 
3786 int
3787 i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
3788 		       struct drm_file *file_priv)
3789 {
3790 	struct drm_i915_gem_madvise *args = data;
3791 	struct drm_i915_gem_object *obj;
3792 	int ret;
3793 
3794 	switch (args->madv) {
3795 	case I915_MADV_DONTNEED:
3796 	case I915_MADV_WILLNEED:
3797 	    break;
3798 	default:
3799 	    return -EINVAL;
3800 	}
3801 
3802 	ret = i915_mutex_lock_interruptible(dev);
3803 	if (ret)
3804 		return ret;
3805 
3806 	obj = to_intel_bo(drm_gem_object_lookup(dev, file_priv, args->handle));
3807 	if (&obj->base == NULL) {
3808 		ret = -ENOENT;
3809 		goto unlock;
3810 	}
3811 
3812 	if (obj->pin_count) {
3813 		ret = -EINVAL;
3814 		goto out;
3815 	}
3816 
3817 	if (obj->madv != __I915_MADV_PURGED)
3818 		obj->madv = args->madv;
3819 
3820 	/* if the object is no longer attached, discard its backing storage */
3821 	if (i915_gem_object_is_purgeable(obj) && obj->pages == NULL)
3822 		i915_gem_object_truncate(obj);
3823 
3824 	args->retained = obj->madv != __I915_MADV_PURGED;
3825 
3826 out:
3827 	drm_gem_object_unreference(&obj->base);
3828 unlock:
3829 	mutex_unlock(&dev->struct_mutex);
3830 	return ret;
3831 }
3832 
3833 void i915_gem_object_init(struct drm_i915_gem_object *obj,
3834 			  const struct drm_i915_gem_object_ops *ops)
3835 {
3836 	INIT_LIST_HEAD(&obj->mm_list);
3837 	INIT_LIST_HEAD(&obj->global_list);
3838 	INIT_LIST_HEAD(&obj->ring_list);
3839 	INIT_LIST_HEAD(&obj->exec_list);
3840 
3841 	obj->ops = ops;
3842 
3843 	obj->fence_reg = I915_FENCE_REG_NONE;
3844 	obj->madv = I915_MADV_WILLNEED;
3845 	/* Avoid an unnecessary call to unbind on the first bind. */
3846 	obj->map_and_fenceable = true;
3847 
3848 	i915_gem_info_add_obj(obj->base.dev->dev_private, obj->base.size);
3849 }
3850 
3851 static const struct drm_i915_gem_object_ops i915_gem_object_ops = {
3852 	.get_pages = i915_gem_object_get_pages_gtt,
3853 	.put_pages = i915_gem_object_put_pages_gtt,
3854 };
3855 
3856 struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
3857 						  size_t size)
3858 {
3859 	struct drm_i915_gem_object *obj;
3860 #if 0
3861 	struct address_space *mapping;
3862 	u32 mask;
3863 #endif
3864 
3865 	obj = kmalloc(sizeof(*obj), M_DRM, M_WAITOK | M_ZERO);
3866 	if (obj == NULL)
3867 		return NULL;
3868 
3869 	if (drm_gem_object_init(dev, &obj->base, size) != 0) {
3870 		kfree(obj);
3871 		return NULL;
3872 	}
3873 
3874 #if 0
3875 	mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
3876 	if (IS_CRESTLINE(dev) || IS_BROADWATER(dev)) {
3877 		/* 965gm cannot relocate objects above 4GiB. */
3878 		mask &= ~__GFP_HIGHMEM;
3879 		mask |= __GFP_DMA32;
3880 	}
3881 
3882 	mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
3883 	mapping_set_gfp_mask(mapping, mask);
3884 #endif
3885 
3886 	i915_gem_object_init(obj, &i915_gem_object_ops);
3887 
3888 	obj->base.write_domain = I915_GEM_DOMAIN_CPU;
3889 	obj->base.read_domains = I915_GEM_DOMAIN_CPU;
3890 
3891 	if (HAS_LLC(dev)) {
3892 		/* On some devices, we can have the GPU use the LLC (the CPU
3893 		 * cache) for about a 10% performance improvement
3894 		 * compared to uncached.  Graphics requests other than
3895 		 * display scanout are coherent with the CPU in
3896 		 * accessing this cache.  This means in this mode we
3897 		 * don't need to clflush on the CPU side, and on the
3898 		 * GPU side we only need to flush internal caches to
3899 		 * get data visible to the CPU.
3900 		 *
3901 		 * However, we maintain the display planes as UC, and so
3902 		 * need to rebind when first used as such.
3903 		 */
3904 		obj->cache_level = I915_CACHE_LLC;
3905 	} else
3906 		obj->cache_level = I915_CACHE_NONE;
3907 
3908 	return obj;
3909 }
3910 
3911 int i915_gem_init_object(struct drm_gem_object *obj)
3912 {
3913 	BUG();
3914 
3915 	return 0;
3916 }
3917 
3918 void i915_gem_free_object(struct drm_gem_object *gem_obj)
3919 {
3920 	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
3921 	struct drm_device *dev = obj->base.dev;
3922 	drm_i915_private_t *dev_priv = dev->dev_private;
3923 
3924 	if (obj->phys_obj)
3925 		i915_gem_detach_phys_object(dev, obj);
3926 
3927 	obj->pin_count = 0;
3928 	if (WARN_ON(i915_gem_object_unbind(obj) == -ERESTARTSYS)) {
3929 		bool was_interruptible;
3930 
3931 		was_interruptible = dev_priv->mm.interruptible;
3932 		dev_priv->mm.interruptible = false;
3933 
3934 		WARN_ON(i915_gem_object_unbind(obj));
3935 
3936 		dev_priv->mm.interruptible = was_interruptible;
3937 	}
3938 
3939 	/* Stolen objects don't hold a ref, but do hold pin count. Fix that up
3940 	 * before progressing. */
3941 	if (obj->stolen)
3942 		i915_gem_object_unpin_pages(obj);
3943 
3944 	if (WARN_ON(obj->pages_pin_count))
3945 		obj->pages_pin_count = 0;
3946 	i915_gem_object_put_pages(obj);
3947 	drm_gem_free_mmap_offset(&obj->base);
3948 
3949 	BUG_ON(obj->pages);
3950 
3951 	drm_gem_object_release(&obj->base);
3952 	i915_gem_info_remove_obj(dev_priv, obj->base.size);
3953 
3954 	kfree(obj->bit_17);
3955 	i915_gem_object_free(obj);
3956 }
3957 
3958 int
3959 i915_gem_idle(struct drm_device *dev)
3960 {
3961 	drm_i915_private_t *dev_priv = dev->dev_private;
3962 	int ret;
3963 
3964 	mutex_lock(&dev->struct_mutex);
3965 
3966 	if (dev_priv->mm.suspended) {
3967 		mutex_unlock(&dev->struct_mutex);
3968 		return 0;
3969 	}
3970 
3971 	ret = i915_gpu_idle(dev);
3972 	if (ret) {
3973 		mutex_unlock(&dev->struct_mutex);
3974 		return ret;
3975 	}
3976 	i915_gem_retire_requests(dev);
3977 
3978 	/* Under UMS, be paranoid and evict. */
3979 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
3980 		i915_gem_evict_everything(dev);
3981 
3982 	/* Hack!  Don't let anybody do execbuf while we don't control the chip.
3983 	 * We need to replace this with a semaphore, or something.
3984 	 * And not confound mm.suspended!
3985 	 */
3986 	dev_priv->mm.suspended = 1;
3987 	del_timer_sync(&dev_priv->gpu_error.hangcheck_timer);
3988 
3989 	i915_kernel_lost_context(dev);
3990 	i915_gem_cleanup_ringbuffer(dev);
3991 
3992 	mutex_unlock(&dev->struct_mutex);
3993 
3994 	/* Cancel the retire work handler, which should be idle now. */
3995 	cancel_delayed_work_sync(&dev_priv->mm.retire_work);
3996 
3997 	return 0;
3998 }
3999 
4000 void i915_gem_l3_remap(struct drm_device *dev)
4001 {
4002 	drm_i915_private_t *dev_priv = dev->dev_private;
4003 	u32 misccpctl;
4004 	int i;
4005 
4006 	if (!HAS_L3_GPU_CACHE(dev))
4007 		return;
4008 
4009 	if (!dev_priv->l3_parity.remap_info)
4010 		return;
4011 
4012 	misccpctl = I915_READ(GEN7_MISCCPCTL);
4013 	I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
4014 	POSTING_READ(GEN7_MISCCPCTL);
4015 
4016 	for (i = 0; i < GEN7_L3LOG_SIZE; i += 4) {
4017 		u32 remap = I915_READ(GEN7_L3LOG_BASE + i);
4018 		if (remap && remap != dev_priv->l3_parity.remap_info[i/4])
4019 			DRM_DEBUG("0x%x was already programmed to %x\n",
4020 				  GEN7_L3LOG_BASE + i, remap);
4021 		if (remap && !dev_priv->l3_parity.remap_info[i/4])
4022 			DRM_DEBUG_DRIVER("Clearing remapped register\n");
4023 		I915_WRITE(GEN7_L3LOG_BASE + i, dev_priv->l3_parity.remap_info[i/4]);
4024 	}
4025 
4026 	/* Make sure all the writes land before disabling dop clock gating */
4027 	POSTING_READ(GEN7_L3LOG_BASE);
4028 
4029 	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
4030 }
4031 
4032 void i915_gem_init_swizzling(struct drm_device *dev)
4033 {
4034 	drm_i915_private_t *dev_priv = dev->dev_private;
4035 
4036 	if (INTEL_INFO(dev)->gen < 5 ||
4037 	    dev_priv->mm.bit_6_swizzle_x == I915_BIT_6_SWIZZLE_NONE)
4038 		return;
4039 
4040 	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
4041 				 DISP_TILE_SURFACE_SWIZZLING);
4042 
4043 	if (IS_GEN5(dev))
4044 		return;
4045 
4046 	I915_WRITE(TILECTL, I915_READ(TILECTL) | TILECTL_SWZCTL);
4047 	if (IS_GEN6(dev))
4048 		I915_WRITE(ARB_MODE, _MASKED_BIT_ENABLE(ARB_MODE_SWIZZLE_SNB));
4049 	else if (IS_GEN7(dev))
4050 		I915_WRITE(ARB_MODE, _MASKED_BIT_ENABLE(ARB_MODE_SWIZZLE_IVB));
4051 	else
4052 		BUG();
4053 }
4054 
4055 static bool
4056 intel_enable_blt(struct drm_device *dev)
4057 {
4058 	int revision;
4059 
4060 	if (!HAS_BLT(dev))
4061 		return false;
4062 
4063 	/* The blitter was dysfunctional on early prototypes */
4064 	revision = pci_read_config(dev->dev, PCIR_REVID, 1);
4065 	if (IS_GEN6(dev) && revision < 8) {
4066 		DRM_INFO("BLT not supported on this pre-production hardware;"
4067 			 " graphics performance will be degraded.\n");
4068 		return false;
4069 	}
4070 
4071 	return true;
4072 }
4073 
4074 static int i915_gem_init_rings(struct drm_device *dev)
4075 {
4076 	struct drm_i915_private *dev_priv = dev->dev_private;
4077 	int ret;
4078 
4079 	ret = intel_init_render_ring_buffer(dev);
4080 	if (ret)
4081 		return ret;
4082 
4083 	if (HAS_BSD(dev)) {
4084 		ret = intel_init_bsd_ring_buffer(dev);
4085 		if (ret)
4086 			goto cleanup_render_ring;
4087 	}
4088 
4089 	if (intel_enable_blt(dev)) {
4090 		ret = intel_init_blt_ring_buffer(dev);
4091 		if (ret)
4092 			goto cleanup_bsd_ring;
4093 	}
4094 
4095 	if (HAS_VEBOX(dev)) {
4096 		ret = intel_init_vebox_ring_buffer(dev);
4097 		if (ret)
4098 			goto cleanup_blt_ring;
4099 	}
4100 
4101 
4102 	ret = i915_gem_set_seqno(dev, ((u32)~0 - 0x1000));
4103 	if (ret)
4104 		goto cleanup_vebox_ring;
4105 
4106 	return 0;
4107 
4108 cleanup_vebox_ring:
4109 	intel_cleanup_ring_buffer(&dev_priv->ring[VECS]);
4110 cleanup_blt_ring:
4111 	intel_cleanup_ring_buffer(&dev_priv->ring[BCS]);
4112 cleanup_bsd_ring:
4113 	intel_cleanup_ring_buffer(&dev_priv->ring[VCS]);
4114 cleanup_render_ring:
4115 	intel_cleanup_ring_buffer(&dev_priv->ring[RCS]);
4116 
4117 	return ret;
4118 }
4119 
4120 int
4121 i915_gem_init_hw(struct drm_device *dev)
4122 {
4123 	drm_i915_private_t *dev_priv = dev->dev_private;
4124 	int ret;
4125 
4126 #if 0
4127 	if (INTEL_INFO(dev)->gen < 6 && !intel_enable_gtt())
4128 		return -EIO;
4129 #endif
4130 
4131 	if (IS_HASWELL(dev) && (I915_READ(0x120010) == 1))
4132 		I915_WRITE(0x9008, I915_READ(0x9008) | 0xf0000);
4133 
4134 	if (HAS_PCH_NOP(dev)) {
4135 		u32 temp = I915_READ(GEN7_MSG_CTL);
4136 		temp &= ~(WAIT_FOR_PCH_FLR_ACK | WAIT_FOR_PCH_RESET_ACK);
4137 		I915_WRITE(GEN7_MSG_CTL, temp);
4138 	}
4139 
4140 	i915_gem_l3_remap(dev);
4141 
4142 	i915_gem_init_swizzling(dev);
4143 
4144 	ret = i915_gem_init_rings(dev);
4145 	if (ret)
4146 		return ret;
4147 
4148 	/*
4149 	 * XXX: There was some w/a described somewhere suggesting loading
4150 	 * contexts before PPGTT.
4151 	 */
4152 	i915_gem_context_init(dev);
4153 	if (dev_priv->mm.aliasing_ppgtt) {
4154 		ret = dev_priv->mm.aliasing_ppgtt->enable(dev);
4155 		if (ret) {
4156 			i915_gem_cleanup_aliasing_ppgtt(dev);
4157 			DRM_INFO("PPGTT enable failed. This is not fatal, but unexpected\n");
4158 		}
4159 	}
4160 
4161 	return 0;
4162 }
4163 
4164 int i915_gem_init(struct drm_device *dev)
4165 {
4166 	struct drm_i915_private *dev_priv = dev->dev_private;
4167 	int ret;
4168 
4169 	mutex_lock(&dev->struct_mutex);
4170 
4171 	if (IS_VALLEYVIEW(dev)) {
4172 		/* VLVA0 (potential hack), BIOS isn't actually waking us */
4173 		I915_WRITE(VLV_GTLC_WAKE_CTRL, 1);
4174 		if (wait_for((I915_READ(VLV_GTLC_PW_STATUS) & 1) == 1, 10))
4175 			DRM_DEBUG_DRIVER("allow wake ack timed out\n");
4176 	}
4177 
4178 	i915_gem_init_global_gtt(dev);
4179 
4180 	ret = i915_gem_init_hw(dev);
4181 	mutex_unlock(&dev->struct_mutex);
4182 	if (ret) {
4183 		i915_gem_cleanup_aliasing_ppgtt(dev);
4184 		return ret;
4185 	}
4186 
4187 	/* Allow hardware batchbuffers unless told otherwise, but not for KMS. */
4188 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
4189 		dev_priv->dri1.allow_batchbuffer = 1;
4190 	return 0;
4191 }
4192 
4193 void
4194 i915_gem_cleanup_ringbuffer(struct drm_device *dev)
4195 {
4196 	drm_i915_private_t *dev_priv = dev->dev_private;
4197 	struct intel_ring_buffer *ring;
4198 	int i;
4199 
4200 	for_each_ring(ring, dev_priv, i)
4201 		intel_cleanup_ring_buffer(ring);
4202 }
4203 
4204 int
4205 i915_gem_entervt_ioctl(struct drm_device *dev, void *data,
4206 		       struct drm_file *file_priv)
4207 {
4208 	drm_i915_private_t *dev_priv = dev->dev_private;
4209 	int ret;
4210 
4211 	if (drm_core_check_feature(dev, DRIVER_MODESET))
4212 		return 0;
4213 
4214 	if (i915_reset_in_progress(&dev_priv->gpu_error)) {
4215 		DRM_ERROR("Reenabling wedged hardware, good luck\n");
4216 		atomic_set(&dev_priv->gpu_error.reset_counter, 0);
4217 	}
4218 
4219 	mutex_lock(&dev->struct_mutex);
4220 	dev_priv->mm.suspended = 0;
4221 
4222 	ret = i915_gem_init_hw(dev);
4223 	if (ret != 0) {
4224 		mutex_unlock(&dev->struct_mutex);
4225 		return ret;
4226 	}
4227 
4228 	KASSERT(list_empty(&dev_priv->mm.active_list), ("active list"));
4229 	mutex_unlock(&dev->struct_mutex);
4230 
4231 	ret = drm_irq_install(dev);
4232 	if (ret)
4233 		goto cleanup_ringbuffer;
4234 
4235 	return 0;
4236 
4237 cleanup_ringbuffer:
4238 	mutex_lock(&dev->struct_mutex);
4239 	i915_gem_cleanup_ringbuffer(dev);
4240 	dev_priv->mm.suspended = 1;
4241 	mutex_unlock(&dev->struct_mutex);
4242 
4243 	return ret;
4244 }
4245 
4246 int
4247 i915_gem_leavevt_ioctl(struct drm_device *dev, void *data,
4248 		       struct drm_file *file_priv)
4249 {
4250 	if (drm_core_check_feature(dev, DRIVER_MODESET))
4251 		return 0;
4252 
4253 	drm_irq_uninstall(dev);
4254 	return i915_gem_idle(dev);
4255 }
4256 
4257 void
4258 i915_gem_lastclose(struct drm_device *dev)
4259 {
4260 	int ret;
4261 
4262 	if (drm_core_check_feature(dev, DRIVER_MODESET))
4263 		return;
4264 
4265 	ret = i915_gem_idle(dev);
4266 	if (ret)
4267 		DRM_ERROR("failed to idle hardware: %d\n", ret);
4268 }
4269 
4270 static void
4271 init_ring_lists(struct intel_ring_buffer *ring)
4272 {
4273 	INIT_LIST_HEAD(&ring->active_list);
4274 	INIT_LIST_HEAD(&ring->request_list);
4275 }
4276 
4277 void
4278 i915_gem_load(struct drm_device *dev)
4279 {
4280 	int i;
4281 	drm_i915_private_t *dev_priv = dev->dev_private;
4282 
4283 	INIT_LIST_HEAD(&dev_priv->mm.active_list);
4284 	INIT_LIST_HEAD(&dev_priv->mm.inactive_list);
4285 	INIT_LIST_HEAD(&dev_priv->mm.unbound_list);
4286 	INIT_LIST_HEAD(&dev_priv->mm.bound_list);
4287 	INIT_LIST_HEAD(&dev_priv->mm.fence_list);
4288 	for (i = 0; i < I915_NUM_RINGS; i++)
4289 		init_ring_lists(&dev_priv->ring[i]);
4290 	for (i = 0; i < I915_MAX_NUM_FENCES; i++)
4291 		INIT_LIST_HEAD(&dev_priv->fence_regs[i].lru_list);
4292 	INIT_DELAYED_WORK(&dev_priv->mm.retire_work,
4293 			  i915_gem_retire_work_handler);
4294 	init_waitqueue_head(&dev_priv->gpu_error.reset_queue);
4295 
4296 	/* On GEN3 we really need to make sure the ARB C3 LP bit is set */
4297 	if (IS_GEN3(dev)) {
4298 		I915_WRITE(MI_ARB_STATE,
4299 			   _MASKED_BIT_ENABLE(MI_ARB_C3_LP_WRITE_ENABLE));
4300 	}
4301 
4302 	dev_priv->relative_constants_mode = I915_EXEC_CONSTANTS_REL_GENERAL;
4303 
4304 	/* Old X drivers will take 0-2 for front, back, depth buffers */
4305 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
4306 		dev_priv->fence_reg_start = 3;
4307 
4308 	if (INTEL_INFO(dev)->gen >= 7 && !IS_VALLEYVIEW(dev))
4309 		dev_priv->num_fence_regs = 32;
4310 	else if (INTEL_INFO(dev)->gen >= 4 || IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
4311 		dev_priv->num_fence_regs = 16;
4312 	else
4313 		dev_priv->num_fence_regs = 8;
4314 
4315 	/* Initialize fence registers to zero */
4316 	INIT_LIST_HEAD(&dev_priv->mm.fence_list);
4317 	i915_gem_restore_fences(dev);
4318 
4319 	i915_gem_detect_bit_6_swizzle(dev);
4320 	init_waitqueue_head(&dev_priv->pending_flip_queue);
4321 
4322 	dev_priv->mm.interruptible = true;
4323 
4324 #if 0
4325 	dev_priv->mm.inactive_shrinker.shrink = i915_gem_inactive_shrink;
4326 	dev_priv->mm.inactive_shrinker.seeks = DEFAULT_SEEKS;
4327 	register_shrinker(&dev_priv->mm.inactive_shrinker);
4328 #else
4329 	dev_priv->mm.inactive_shrinker = EVENTHANDLER_REGISTER(vm_lowmem,
4330 	    i915_gem_lowmem, dev, EVENTHANDLER_PRI_ANY);
4331 #endif
4332 }
4333 
4334 /*
4335  * Create a physically contiguous memory object for this object
4336  * e.g. for cursor + overlay regs
4337  */
4338 static int i915_gem_init_phys_object(struct drm_device *dev,
4339 				     int id, int size, int align)
4340 {
4341 	drm_i915_private_t *dev_priv = dev->dev_private;
4342 	struct drm_i915_gem_phys_object *phys_obj;
4343 	int ret;
4344 
4345 	if (dev_priv->mm.phys_objs[id - 1] || !size)
4346 		return 0;
4347 
4348 	phys_obj = kzalloc(sizeof(struct drm_i915_gem_phys_object), GFP_KERNEL);
4349 	if (!phys_obj)
4350 		return -ENOMEM;
4351 
4352 	phys_obj->id = id;
4353 
4354 	phys_obj->handle = drm_pci_alloc(dev, size, align);
4355 	if (!phys_obj->handle) {
4356 		ret = -ENOMEM;
4357 		goto kfree_obj;
4358 	}
4359 	pmap_change_attr((vm_offset_t)phys_obj->handle->vaddr,
4360 	    size / PAGE_SIZE, PAT_WRITE_COMBINING);
4361 
4362 	dev_priv->mm.phys_objs[id - 1] = phys_obj;
4363 
4364 	return 0;
4365 
4366 kfree_obj:
4367 	kfree(phys_obj);
4368 	return ret;
4369 }
4370 
4371 static void i915_gem_free_phys_object(struct drm_device *dev, int id)
4372 {
4373 	drm_i915_private_t *dev_priv = dev->dev_private;
4374 	struct drm_i915_gem_phys_object *phys_obj;
4375 
4376 	if (!dev_priv->mm.phys_objs[id - 1])
4377 		return;
4378 
4379 	phys_obj = dev_priv->mm.phys_objs[id - 1];
4380 	if (phys_obj->cur_obj) {
4381 		i915_gem_detach_phys_object(dev, phys_obj->cur_obj);
4382 	}
4383 
4384 	drm_pci_free(dev, phys_obj->handle);
4385 	kfree(phys_obj);
4386 	dev_priv->mm.phys_objs[id - 1] = NULL;
4387 }
4388 
4389 void i915_gem_free_all_phys_object(struct drm_device *dev)
4390 {
4391 	int i;
4392 
4393 	for (i = I915_GEM_PHYS_CURSOR_0; i <= I915_MAX_PHYS_OBJECT; i++)
4394 		i915_gem_free_phys_object(dev, i);
4395 }
4396 
4397 void i915_gem_detach_phys_object(struct drm_device *dev,
4398 				 struct drm_i915_gem_object *obj)
4399 {
4400 	struct vm_object *mapping = obj->base.vm_obj;
4401 	char *vaddr;
4402 	int i;
4403 	int page_count;
4404 
4405 	if (!obj->phys_obj)
4406 		return;
4407 	vaddr = obj->phys_obj->handle->vaddr;
4408 
4409 	page_count = obj->base.size / PAGE_SIZE;
4410 	VM_OBJECT_LOCK(obj->base.vm_obj);
4411 	for (i = 0; i < page_count; i++) {
4412 		struct vm_page *page = shmem_read_mapping_page(mapping, i);
4413 		if (!IS_ERR(page)) {
4414 			VM_OBJECT_UNLOCK(obj->base.vm_obj);
4415 			char *dst = kmap_atomic(page);
4416 			memcpy(dst, vaddr + i*PAGE_SIZE, PAGE_SIZE);
4417 			kunmap_atomic(dst);
4418 
4419 			drm_clflush_pages(&page, 1);
4420 
4421 #if 0
4422 			set_page_dirty(page);
4423 			mark_page_accessed(page);
4424 			page_cache_release(page);
4425 #endif
4426 			VM_OBJECT_LOCK(obj->base.vm_obj);
4427 			vm_page_reference(page);
4428 			vm_page_dirty(page);
4429 			vm_page_busy_wait(page, FALSE, "i915gem");
4430 			vm_page_unwire(page, 0);
4431 			vm_page_wakeup(page);
4432 		}
4433 	}
4434 	VM_OBJECT_UNLOCK(obj->base.vm_obj);
4435 	intel_gtt_chipset_flush();
4436 
4437 	obj->phys_obj->cur_obj = NULL;
4438 	obj->phys_obj = NULL;
4439 }
4440 
4441 int
4442 i915_gem_attach_phys_object(struct drm_device *dev,
4443 			    struct drm_i915_gem_object *obj,
4444 			    int id,
4445 			    int align)
4446 {
4447 	struct vm_object *mapping = obj->base.vm_obj;
4448 	drm_i915_private_t *dev_priv = dev->dev_private;
4449 	int ret = 0;
4450 	int page_count;
4451 	int i;
4452 
4453 	if (id > I915_MAX_PHYS_OBJECT)
4454 		return -EINVAL;
4455 
4456 	if (obj->phys_obj) {
4457 		if (obj->phys_obj->id == id)
4458 			return 0;
4459 		i915_gem_detach_phys_object(dev, obj);
4460 	}
4461 
4462 	/* create a new object */
4463 	if (!dev_priv->mm.phys_objs[id - 1]) {
4464 		ret = i915_gem_init_phys_object(dev, id,
4465 						obj->base.size, align);
4466 		if (ret) {
4467 			DRM_ERROR("failed to init phys object %d size: %zu\n",
4468 				  id, obj->base.size);
4469 			return ret;
4470 		}
4471 	}
4472 
4473 	/* bind to the object */
4474 	obj->phys_obj = dev_priv->mm.phys_objs[id - 1];
4475 	obj->phys_obj->cur_obj = obj;
4476 
4477 	page_count = obj->base.size / PAGE_SIZE;
4478 
4479 	VM_OBJECT_LOCK(obj->base.vm_obj);
4480 	for (i = 0; i < page_count; i++) {
4481 		struct vm_page *page;
4482 		char *dst, *src;
4483 
4484 		page = shmem_read_mapping_page(mapping, i);
4485 		VM_OBJECT_UNLOCK(obj->base.vm_obj);
4486 		if (IS_ERR(page))
4487 			return PTR_ERR(page);
4488 
4489 		src = kmap_atomic(page);
4490 		dst = (char*)obj->phys_obj->handle->vaddr + (i * PAGE_SIZE);
4491 		memcpy(dst, src, PAGE_SIZE);
4492 		kunmap_atomic(src);
4493 
4494 #if 0
4495 		mark_page_accessed(page);
4496 		page_cache_release(page);
4497 #endif
4498 		VM_OBJECT_LOCK(obj->base.vm_obj);
4499 		vm_page_reference(page);
4500 		vm_page_busy_wait(page, FALSE, "i915gem");
4501 		vm_page_unwire(page, 0);
4502 		vm_page_wakeup(page);
4503 	}
4504 	VM_OBJECT_UNLOCK(obj->base.vm_obj);
4505 
4506 	return 0;
4507 }
4508 
4509 static int
4510 i915_gem_phys_pwrite(struct drm_device *dev,
4511 		     struct drm_i915_gem_object *obj,
4512 		     struct drm_i915_gem_pwrite *args,
4513 		     struct drm_file *file_priv)
4514 {
4515 	void *vaddr = (char *)obj->phys_obj->handle->vaddr + args->offset;
4516 	char __user *user_data = (char __user *) (uintptr_t) args->data_ptr;
4517 
4518 	if (copyin_nofault(user_data, vaddr, args->size) != 0) {
4519 		unsigned long unwritten;
4520 
4521 		/* The physical object once assigned is fixed for the lifetime
4522 		 * of the obj, so we can safely drop the lock and continue
4523 		 * to access vaddr.
4524 		 */
4525 		mutex_unlock(&dev->struct_mutex);
4526 		unwritten = copy_from_user(vaddr, user_data, args->size);
4527 		mutex_lock(&dev->struct_mutex);
4528 		if (unwritten)
4529 			return -EFAULT;
4530 	}
4531 
4532 	i915_gem_chipset_flush(dev);
4533 	return 0;
4534 }
4535 
4536 void i915_gem_release(struct drm_device *dev, struct drm_file *file)
4537 {
4538 	struct drm_i915_file_private *file_priv = file->driver_priv;
4539 
4540 	/* Clean up our request list when the client is going away, so that
4541 	 * later retire_requests won't dereference our soon-to-be-gone
4542 	 * file_priv.
4543 	 */
4544 	spin_lock(&file_priv->mm.lock);
4545 	while (!list_empty(&file_priv->mm.request_list)) {
4546 		struct drm_i915_gem_request *request;
4547 
4548 		request = list_first_entry(&file_priv->mm.request_list,
4549 					   struct drm_i915_gem_request,
4550 					   client_list);
4551 		list_del(&request->client_list);
4552 		request->file_priv = NULL;
4553 	}
4554 	spin_unlock(&file_priv->mm.lock);
4555 }
4556 
4557 int
4558 i915_gem_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
4559     vm_ooffset_t foff, struct ucred *cred, u_short *color)
4560 {
4561 
4562 	*color = 0; /* XXXKIB */
4563 	return (0);
4564 }
4565 
4566 void
4567 i915_gem_pager_dtor(void *handle)
4568 {
4569 	struct drm_gem_object *obj;
4570 	struct drm_device *dev;
4571 
4572 	obj = handle;
4573 	dev = obj->dev;
4574 
4575 	mutex_lock(&dev->struct_mutex);
4576 	drm_gem_free_mmap_offset(obj);
4577 	i915_gem_release_mmap(to_intel_bo(obj));
4578 	drm_gem_object_unreference(obj);
4579 	mutex_unlock(&dev->struct_mutex);
4580 }
4581 
4582 #define	GEM_PARANOID_CHECK_GTT 0
4583 #if GEM_PARANOID_CHECK_GTT
4584 static void
4585 i915_gem_assert_pages_not_mapped(struct drm_device *dev, vm_page_t *ma,
4586     int page_count)
4587 {
4588 	struct drm_i915_private *dev_priv;
4589 	vm_paddr_t pa;
4590 	unsigned long start, end;
4591 	u_int i;
4592 	int j;
4593 
4594 	dev_priv = dev->dev_private;
4595 	start = OFF_TO_IDX(dev_priv->mm.gtt_start);
4596 	end = OFF_TO_IDX(dev_priv->mm.gtt_end);
4597 	for (i = start; i < end; i++) {
4598 		pa = intel_gtt_read_pte_paddr(i);
4599 		for (j = 0; j < page_count; j++) {
4600 			if (pa == VM_PAGE_TO_PHYS(ma[j])) {
4601 				panic("Page %p in GTT pte index %d pte %x",
4602 				    ma[i], i, intel_gtt_read_pte(i));
4603 			}
4604 		}
4605 	}
4606 	obj->fence_dirty = false;
4607 }
4608 #endif
4609 
4610 static int
4611 i915_gpu_is_active(struct drm_device *dev)
4612 {
4613 	drm_i915_private_t *dev_priv = dev->dev_private;
4614 
4615 	return !list_empty(&dev_priv->mm.active_list);
4616 }
4617 
4618 static void
4619 i915_gem_lowmem(void *arg)
4620 {
4621 	struct drm_device *dev;
4622 	struct drm_i915_private *dev_priv;
4623 	struct drm_i915_gem_object *obj, *next;
4624 	int cnt, cnt_fail, cnt_total;
4625 
4626 	dev = arg;
4627 	dev_priv = dev->dev_private;
4628 
4629 	if (lockmgr(&dev->struct_mutex, LK_EXCLUSIVE|LK_NOWAIT))
4630 		return;
4631 
4632 rescan:
4633 	/* first scan for clean buffers */
4634 	i915_gem_retire_requests(dev);
4635 
4636 	cnt_total = cnt_fail = cnt = 0;
4637 
4638 	list_for_each_entry_safe(obj, next, &dev_priv->mm.inactive_list,
4639 	    mm_list) {
4640 		if (i915_gem_object_is_purgeable(obj)) {
4641 			if (i915_gem_object_unbind(obj) != 0)
4642 				cnt_total++;
4643 		} else
4644 			cnt_total++;
4645 	}
4646 
4647 	/* second pass, evict/count anything still on the inactive list */
4648 	list_for_each_entry_safe(obj, next, &dev_priv->mm.inactive_list,
4649 	    mm_list) {
4650 		if (i915_gem_object_unbind(obj) == 0)
4651 			cnt++;
4652 		else
4653 			cnt_fail++;
4654 	}
4655 
4656 	if (cnt_fail > cnt_total / 100 && i915_gpu_is_active(dev)) {
4657 		/*
4658 		 * We are desperate for pages, so as a last resort, wait
4659 		 * for the GPU to finish and discard whatever we can.
4660 		 * This has a dramatic impact to reduce the number of
4661 		 * OOM-killer events whilst running the GPU aggressively.
4662 		 */
4663 		if (i915_gpu_idle(dev) == 0)
4664 			goto rescan;
4665 	}
4666 	mutex_unlock(&dev->struct_mutex);
4667 }
4668