xref: /netbsd-src/sys/external/bsd/drm2/dist/drm/via/via_dma.c (revision 41ec02673d281bbb3d38e6c78504ce6e30c228c1)
1 /*	$NetBSD: via_dma.c,v 1.6 2021/12/18 23:45:44 riastradh Exp $	*/
2 
3 /* via_dma.c -- DMA support for the VIA Unichrome/Pro
4  *
5  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
6  * All Rights Reserved.
7  *
8  * Copyright 2004 Digeo, Inc., Palo Alto, CA, U.S.A.
9  * All Rights Reserved.
10  *
11  * Copyright 2004 The Unichrome project.
12  * All Rights Reserved.
13  *
14  * Permission is hereby granted, free of charge, to any person obtaining a
15  * copy of this software and associated documentation files (the "Software"),
16  * to deal in the Software without restriction, including without limitation
17  * the rights to use, copy, modify, merge, publish, distribute, sub license,
18  * and/or sell copies of the Software, and to permit persons to whom the
19  * Software is furnished to do so, subject to the following conditions:
20  *
21  * The above copyright notice and this permission notice (including the
22  * next paragraph) shall be included in all copies or substantial portions
23  * of the Software.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
28  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
29  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
30  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
31  * USE OR OTHER DEALINGS IN THE SOFTWARE.
32  *
33  * Authors:
34  *    Tungsten Graphics,
35  *    Erdi Chen,
36  *    Thomas Hellstrom.
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: via_dma.c,v 1.6 2021/12/18 23:45:44 riastradh Exp $");
41 
42 #include <linux/delay.h>
43 #include <linux/uaccess.h>
44 
45 #include <drm/drm.h>
46 #include <drm/drm_agpsupport.h>
47 #include <drm/drm_device.h>
48 #include <drm/drm_file.h>
49 #include <drm/via_drm.h>
50 
51 #include "via_drv.h"
52 #include "via_3d_reg.h"
53 
54 #define CMDBUF_ALIGNMENT_SIZE   (0x100)
55 #define CMDBUF_ALIGNMENT_MASK   (0x0ff)
56 
57 /* defines for VIA 3D registers */
58 #define VIA_REG_STATUS          0x400
59 #define VIA_REG_TRANSET         0x43C
60 #define VIA_REG_TRANSPACE       0x440
61 
62 /* VIA_REG_STATUS(0x400): Engine Status */
63 #define VIA_CMD_RGTR_BUSY       0x00000080	/* Command Regulator is busy */
64 #define VIA_2D_ENG_BUSY         0x00000001	/* 2D Engine is busy */
65 #define VIA_3D_ENG_BUSY         0x00000002	/* 3D Engine is busy */
66 #define VIA_VR_QUEUE_BUSY       0x00020000	/* Virtual Queue is busy */
67 
68 #define SetReg2DAGP(nReg, nData) {				\
69 	*((uint32_t *)(vb)) = ((nReg) >> 2) | HALCYON_HEADER1;	\
70 	*((uint32_t *)(vb) + 1) = (nData);			\
71 	vb = ((uint32_t *)vb) + 2;				\
72 	dev_priv->dma_low += 8;					\
73 }
74 
75 #define via_flush_write_combine() mb()
76 
77 #define VIA_OUT_RING_QW(w1, w2)	do {		\
78 	*vb++ = (w1);				\
79 	*vb++ = (w2);				\
80 	dev_priv->dma_low += 8;			\
81 } while (0)
82 
83 static void via_cmdbuf_start(drm_via_private_t *dev_priv);
84 static void via_cmdbuf_pause(drm_via_private_t *dev_priv);
85 static void via_cmdbuf_reset(drm_via_private_t *dev_priv);
86 static void via_cmdbuf_rewind(drm_via_private_t *dev_priv);
87 static int via_wait_idle(drm_via_private_t *dev_priv);
88 static void via_pad_cache(drm_via_private_t *dev_priv, int qwords);
89 
90 /*
91  * Free space in command buffer.
92  */
93 
via_cmdbuf_space(drm_via_private_t * dev_priv)94 static uint32_t via_cmdbuf_space(drm_via_private_t *dev_priv)
95 {
96 	uint32_t agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
97 	uint32_t hw_addr = *(dev_priv->hw_addr_ptr) - agp_base;
98 
99 	return ((hw_addr <= dev_priv->dma_low) ?
100 		(dev_priv->dma_high + hw_addr - dev_priv->dma_low) :
101 		(hw_addr - dev_priv->dma_low));
102 }
103 
104 /*
105  * How much does the command regulator lag behind?
106  */
107 
via_cmdbuf_lag(drm_via_private_t * dev_priv)108 static uint32_t via_cmdbuf_lag(drm_via_private_t *dev_priv)
109 {
110 	uint32_t agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
111 	uint32_t hw_addr = *(dev_priv->hw_addr_ptr) - agp_base;
112 
113 	return ((hw_addr <= dev_priv->dma_low) ?
114 		(dev_priv->dma_low - hw_addr) :
115 		(dev_priv->dma_wrap + dev_priv->dma_low - hw_addr));
116 }
117 
118 /*
119  * Check that the given size fits in the buffer, otherwise wait.
120  */
121 
122 static inline int
via_cmdbuf_wait(drm_via_private_t * dev_priv,unsigned int size)123 via_cmdbuf_wait(drm_via_private_t *dev_priv, unsigned int size)
124 {
125 	uint32_t agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
126 	uint32_t cur_addr, hw_addr, next_addr;
127 	volatile uint32_t *hw_addr_ptr;
128 	uint32_t count;
129 	hw_addr_ptr = dev_priv->hw_addr_ptr;
130 	cur_addr = dev_priv->dma_low;
131 	next_addr = cur_addr + size + 512 * 1024;
132 	count = 1000000;
133 	do {
134 		hw_addr = *hw_addr_ptr - agp_base;
135 		if (count-- == 0) {
136 			DRM_ERROR
137 			    ("via_cmdbuf_wait timed out hw %x cur_addr %x next_addr %x\n",
138 			     hw_addr, cur_addr, next_addr);
139 			return -1;
140 		}
141 		if  ((cur_addr < hw_addr) && (next_addr >= hw_addr))
142 			msleep(1);
143 	} while ((cur_addr < hw_addr) && (next_addr >= hw_addr));
144 	return 0;
145 }
146 
147 /*
148  * Checks whether buffer head has reach the end. Rewind the ring buffer
149  * when necessary.
150  *
151  * Returns virtual pointer to ring buffer.
152  */
153 
via_check_dma(drm_via_private_t * dev_priv,unsigned int size)154 static inline uint32_t *via_check_dma(drm_via_private_t * dev_priv,
155 				      unsigned int size)
156 {
157 	if ((dev_priv->dma_low + size + 4 * CMDBUF_ALIGNMENT_SIZE) >
158 	    dev_priv->dma_high) {
159 		via_cmdbuf_rewind(dev_priv);
160 	}
161 	if (via_cmdbuf_wait(dev_priv, size) != 0)
162 		return NULL;
163 
164 	return (uint32_t *) (dev_priv->dma_ptr + dev_priv->dma_low);
165 }
166 
via_dma_cleanup(struct drm_device * dev)167 int via_dma_cleanup(struct drm_device *dev)
168 {
169 	if (dev->dev_private) {
170 		drm_via_private_t *dev_priv =
171 		    (drm_via_private_t *) dev->dev_private;
172 
173 		if (dev_priv->ring.virtual_start) {
174 			via_cmdbuf_reset(dev_priv);
175 
176 			drm_legacy_ioremapfree(&dev_priv->ring.map, dev);
177 			dev_priv->ring.virtual_start = NULL;
178 		}
179 
180 	}
181 
182 	return 0;
183 }
184 
via_initialize(struct drm_device * dev,drm_via_private_t * dev_priv,drm_via_dma_init_t * init)185 static int via_initialize(struct drm_device *dev,
186 			  drm_via_private_t *dev_priv,
187 			  drm_via_dma_init_t *init)
188 {
189 	if (!dev_priv || !dev_priv->mmio) {
190 		DRM_ERROR("via_dma_init called before via_map_init\n");
191 		return -EFAULT;
192 	}
193 
194 	if (dev_priv->ring.virtual_start != NULL) {
195 		DRM_ERROR("called again without calling cleanup\n");
196 		return -EFAULT;
197 	}
198 
199 	if (!dev->agp || !dev->agp->base) {
200 		DRM_ERROR("called with no agp memory available\n");
201 		return -EFAULT;
202 	}
203 
204 	if (dev_priv->chipset == VIA_DX9_0) {
205 		DRM_ERROR("AGP DMA is not supported on this chip\n");
206 		return -EINVAL;
207 	}
208 
209 	dev_priv->ring.map.offset = dev->agp->base + init->offset;
210 	dev_priv->ring.map.size = init->size;
211 	dev_priv->ring.map.type = 0;
212 	dev_priv->ring.map.flags = 0;
213 	dev_priv->ring.map.mtrr = 0;
214 
215 	drm_legacy_ioremap(&dev_priv->ring.map, dev);
216 
217 	if (dev_priv->ring.map.handle == NULL) {
218 		via_dma_cleanup(dev);
219 		DRM_ERROR("can not ioremap virtual address for"
220 			  " ring buffer\n");
221 		return -ENOMEM;
222 	}
223 
224 	dev_priv->ring.virtual_start = dev_priv->ring.map.handle;
225 
226 	dev_priv->dma_ptr = dev_priv->ring.virtual_start;
227 	dev_priv->dma_low = 0;
228 	dev_priv->dma_high = init->size;
229 	dev_priv->dma_wrap = init->size;
230 	dev_priv->dma_offset = init->offset;
231 	dev_priv->last_pause_ptr = NULL;
232 	dev_priv->hw_addr_ptr =
233 		(volatile uint32_t *)((char *)dev_priv->mmio->handle +
234 		init->reg_pause_addr);
235 
236 	via_cmdbuf_start(dev_priv);
237 
238 	return 0;
239 }
240 
via_dma_init(struct drm_device * dev,void * data,struct drm_file * file_priv)241 static int via_dma_init(struct drm_device *dev, void *data, struct drm_file *file_priv)
242 {
243 	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
244 	drm_via_dma_init_t *init = data;
245 	int retcode = 0;
246 
247 	switch (init->func) {
248 	case VIA_INIT_DMA:
249 		if (!capable(CAP_SYS_ADMIN))
250 			retcode = -EPERM;
251 		else
252 			retcode = via_initialize(dev, dev_priv, init);
253 		break;
254 	case VIA_CLEANUP_DMA:
255 		if (!capable(CAP_SYS_ADMIN))
256 			retcode = -EPERM;
257 		else
258 			retcode = via_dma_cleanup(dev);
259 		break;
260 	case VIA_DMA_INITIALIZED:
261 		retcode = (dev_priv->ring.virtual_start != NULL) ?
262 			0 : -EFAULT;
263 		break;
264 	default:
265 		retcode = -EINVAL;
266 		break;
267 	}
268 
269 	return retcode;
270 }
271 
via_dispatch_cmdbuffer(struct drm_device * dev,drm_via_cmdbuffer_t * cmd)272 static int via_dispatch_cmdbuffer(struct drm_device *dev, drm_via_cmdbuffer_t *cmd)
273 {
274 	drm_via_private_t *dev_priv;
275 	uint32_t *vb;
276 	int ret;
277 
278 	dev_priv = (drm_via_private_t *) dev->dev_private;
279 
280 	if (dev_priv->ring.virtual_start == NULL) {
281 		DRM_ERROR("called without initializing AGP ring buffer.\n");
282 		return -EFAULT;
283 	}
284 
285 	if (cmd->size > VIA_PCI_BUF_SIZE)
286 		return -ENOMEM;
287 
288 	if (copy_from_user(dev_priv->pci_buf, cmd->buf, cmd->size))
289 		return -EFAULT;
290 
291 	/*
292 	 * Running this function on AGP memory is dead slow. Therefore
293 	 * we run it on a temporary cacheable system memory buffer and
294 	 * copy it to AGP memory when ready.
295 	 */
296 
297 	if ((ret =
298 	     via_verify_command_stream((uint32_t *) dev_priv->pci_buf,
299 				       cmd->size, dev, 1))) {
300 		return ret;
301 	}
302 
303 	vb = via_check_dma(dev_priv, (cmd->size < 0x100) ? 0x102 : cmd->size);
304 	if (vb == NULL)
305 		return -EAGAIN;
306 
307 	memcpy(vb, dev_priv->pci_buf, cmd->size);
308 
309 	dev_priv->dma_low += cmd->size;
310 
311 	/*
312 	 * Small submissions somehow stalls the CPU. (AGP cache effects?)
313 	 * pad to greater size.
314 	 */
315 
316 	if (cmd->size < 0x100)
317 		via_pad_cache(dev_priv, (0x100 - cmd->size) >> 3);
318 	via_cmdbuf_pause(dev_priv);
319 
320 	return 0;
321 }
322 
via_driver_dma_quiescent(struct drm_device * dev)323 int via_driver_dma_quiescent(struct drm_device *dev)
324 {
325 	drm_via_private_t *dev_priv = dev->dev_private;
326 
327 	if (!via_wait_idle(dev_priv))
328 		return -EBUSY;
329 	return 0;
330 }
331 
via_flush_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)332 static int via_flush_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
333 {
334 
335 	LOCK_TEST_WITH_RETURN(dev, file_priv);
336 
337 	return via_driver_dma_quiescent(dev);
338 }
339 
via_cmdbuffer(struct drm_device * dev,void * data,struct drm_file * file_priv)340 static int via_cmdbuffer(struct drm_device *dev, void *data, struct drm_file *file_priv)
341 {
342 	drm_via_cmdbuffer_t *cmdbuf = data;
343 	int ret;
344 
345 	LOCK_TEST_WITH_RETURN(dev, file_priv);
346 
347 	DRM_DEBUG("buf %p size %lu\n", cmdbuf->buf, cmdbuf->size);
348 
349 	ret = via_dispatch_cmdbuffer(dev, cmdbuf);
350 	return ret;
351 }
352 
via_dispatch_pci_cmdbuffer(struct drm_device * dev,drm_via_cmdbuffer_t * cmd)353 static int via_dispatch_pci_cmdbuffer(struct drm_device *dev,
354 				      drm_via_cmdbuffer_t *cmd)
355 {
356 	drm_via_private_t *dev_priv = dev->dev_private;
357 	int ret;
358 
359 	if (cmd->size > VIA_PCI_BUF_SIZE)
360 		return -ENOMEM;
361 	if (copy_from_user(dev_priv->pci_buf, cmd->buf, cmd->size))
362 		return -EFAULT;
363 
364 	if ((ret =
365 	     via_verify_command_stream((uint32_t *) dev_priv->pci_buf,
366 				       cmd->size, dev, 0))) {
367 		return ret;
368 	}
369 
370 	ret =
371 	    via_parse_command_stream(dev, (const uint32_t *)dev_priv->pci_buf,
372 				     cmd->size);
373 	return ret;
374 }
375 
via_pci_cmdbuffer(struct drm_device * dev,void * data,struct drm_file * file_priv)376 static int via_pci_cmdbuffer(struct drm_device *dev, void *data, struct drm_file *file_priv)
377 {
378 	drm_via_cmdbuffer_t *cmdbuf = data;
379 	int ret;
380 
381 	LOCK_TEST_WITH_RETURN(dev, file_priv);
382 
383 	DRM_DEBUG("buf %p size %lu\n", cmdbuf->buf, cmdbuf->size);
384 
385 	ret = via_dispatch_pci_cmdbuffer(dev, cmdbuf);
386 	return ret;
387 }
388 
via_align_buffer(drm_via_private_t * dev_priv,uint32_t * vb,int qw_count)389 static inline uint32_t *via_align_buffer(drm_via_private_t *dev_priv,
390 					 uint32_t * vb, int qw_count)
391 {
392 	for (; qw_count > 0; --qw_count)
393 		VIA_OUT_RING_QW(HC_DUMMY, HC_DUMMY);
394 	return vb;
395 }
396 
397 /*
398  * This function is used internally by ring buffer management code.
399  *
400  * Returns virtual pointer to ring buffer.
401  */
via_get_dma(drm_via_private_t * dev_priv)402 static inline uint32_t *via_get_dma(drm_via_private_t *dev_priv)
403 {
404 	return (uint32_t *) (dev_priv->dma_ptr + dev_priv->dma_low);
405 }
406 
407 /*
408  * Hooks a segment of data into the tail of the ring-buffer by
409  * modifying the pause address stored in the buffer itself. If
410  * the regulator has already paused, restart it.
411  */
via_hook_segment(drm_via_private_t * dev_priv,uint32_t pause_addr_hi,uint32_t pause_addr_lo,int no_pci_fire)412 static int via_hook_segment(drm_via_private_t *dev_priv,
413 			    uint32_t pause_addr_hi, uint32_t pause_addr_lo,
414 			    int no_pci_fire)
415 {
416 	int paused, count;
417 	volatile uint32_t *paused_at = dev_priv->last_pause_ptr;
418 	uint32_t reader, ptr;
419 	uint32_t diff;
420 
421 	paused = 0;
422 	via_flush_write_combine();
423 	(void) *(volatile uint32_t *)(via_get_dma(dev_priv) - 1);
424 
425 	*paused_at = pause_addr_lo;
426 	via_flush_write_combine();
427 	(void) *paused_at;
428 
429 	reader = *(dev_priv->hw_addr_ptr);
430 	ptr = ((volatile char *)paused_at - dev_priv->dma_ptr) +
431 		dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr + 4;
432 
433 	dev_priv->last_pause_ptr = via_get_dma(dev_priv) - 1;
434 
435 	/*
436 	 * If there is a possibility that the command reader will
437 	 * miss the new pause address and pause on the old one,
438 	 * In that case we need to program the new start address
439 	 * using PCI.
440 	 */
441 
442 	diff = (uint32_t) (ptr - reader) - dev_priv->dma_diff;
443 	count = 10000000;
444 	while (diff == 0 && count--) {
445 		paused = (via_read(dev_priv, 0x41c) & 0x80000000);
446 		if (paused)
447 			break;
448 		reader = *(dev_priv->hw_addr_ptr);
449 		diff = (uint32_t) (ptr - reader) - dev_priv->dma_diff;
450 	}
451 
452 	paused = via_read(dev_priv, 0x41c) & 0x80000000;
453 
454 	if (paused && !no_pci_fire) {
455 		reader = *(dev_priv->hw_addr_ptr);
456 		diff = (uint32_t) (ptr - reader) - dev_priv->dma_diff;
457 		diff &= (dev_priv->dma_high - 1);
458 		if (diff != 0 && diff < (dev_priv->dma_high >> 1)) {
459 			DRM_ERROR("Paused at incorrect address. "
460 				  "0x%08x, 0x%08x 0x%08x\n",
461 				  ptr, reader, dev_priv->dma_diff);
462 		} else if (diff == 0) {
463 			/*
464 			 * There is a concern that these writes may stall the PCI bus
465 			 * if the GPU is not idle. However, idling the GPU first
466 			 * doesn't make a difference.
467 			 */
468 
469 			via_write(dev_priv, VIA_REG_TRANSET, (HC_ParaType_PreCR << 16));
470 			via_write(dev_priv, VIA_REG_TRANSPACE, pause_addr_hi);
471 			via_write(dev_priv, VIA_REG_TRANSPACE, pause_addr_lo);
472 			via_read(dev_priv, VIA_REG_TRANSPACE);
473 		}
474 	}
475 	return paused;
476 }
477 
via_wait_idle(drm_via_private_t * dev_priv)478 static int via_wait_idle(drm_via_private_t *dev_priv)
479 {
480 	int count = 10000000;
481 
482 	while (!(via_read(dev_priv, VIA_REG_STATUS) & VIA_VR_QUEUE_BUSY) && --count)
483 		;
484 
485 	while (count && (via_read(dev_priv, VIA_REG_STATUS) &
486 			   (VIA_CMD_RGTR_BUSY | VIA_2D_ENG_BUSY |
487 			    VIA_3D_ENG_BUSY)))
488 		--count;
489 	return count;
490 }
491 
via_align_cmd(drm_via_private_t * dev_priv,uint32_t cmd_type,uint32_t addr,uint32_t * cmd_addr_hi,uint32_t * cmd_addr_lo,int skip_wait)492 static uint32_t *via_align_cmd(drm_via_private_t *dev_priv, uint32_t cmd_type,
493 			       uint32_t addr, uint32_t *cmd_addr_hi,
494 			       uint32_t *cmd_addr_lo, int skip_wait)
495 {
496 	uint32_t agp_base;
497 	uint32_t cmd_addr, addr_lo, addr_hi;
498 	uint32_t *vb;
499 	uint32_t qw_pad_count;
500 
501 	if (!skip_wait)
502 		via_cmdbuf_wait(dev_priv, 2 * CMDBUF_ALIGNMENT_SIZE);
503 
504 	vb = via_get_dma(dev_priv);
505 	VIA_OUT_RING_QW(HC_HEADER2 | ((VIA_REG_TRANSET >> 2) << 12) |
506 			(VIA_REG_TRANSPACE >> 2), HC_ParaType_PreCR << 16);
507 	agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
508 	qw_pad_count = (CMDBUF_ALIGNMENT_SIZE >> 3) -
509 	    ((dev_priv->dma_low & CMDBUF_ALIGNMENT_MASK) >> 3);
510 
511 	cmd_addr = (addr) ? addr :
512 	    agp_base + dev_priv->dma_low - 8 + (qw_pad_count << 3);
513 	addr_lo = ((HC_SubA_HAGPBpL << 24) | (cmd_type & HC_HAGPBpID_MASK) |
514 		   (cmd_addr & HC_HAGPBpL_MASK));
515 	addr_hi = ((HC_SubA_HAGPBpH << 24) | (cmd_addr >> 24));
516 
517 	vb = via_align_buffer(dev_priv, vb, qw_pad_count - 1);
518 	VIA_OUT_RING_QW(*cmd_addr_hi = addr_hi, *cmd_addr_lo = addr_lo);
519 	return vb;
520 }
521 
via_cmdbuf_start(drm_via_private_t * dev_priv)522 static void via_cmdbuf_start(drm_via_private_t *dev_priv)
523 {
524 	uint32_t pause_addr_lo, pause_addr_hi;
525 	uint32_t start_addr, start_addr_lo;
526 	uint32_t end_addr, end_addr_lo;
527 	uint32_t command;
528 	uint32_t agp_base;
529 	uint32_t ptr;
530 	uint32_t reader;
531 	int count;
532 
533 	dev_priv->dma_low = 0;
534 
535 	agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
536 	start_addr = agp_base;
537 	end_addr = agp_base + dev_priv->dma_high;
538 
539 	start_addr_lo = ((HC_SubA_HAGPBstL << 24) | (start_addr & 0xFFFFFF));
540 	end_addr_lo = ((HC_SubA_HAGPBendL << 24) | (end_addr & 0xFFFFFF));
541 	command = ((HC_SubA_HAGPCMNT << 24) | (start_addr >> 24) |
542 		   ((end_addr & 0xff000000) >> 16));
543 
544 	dev_priv->last_pause_ptr =
545 	    via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0,
546 			  &pause_addr_hi, &pause_addr_lo, 1) - 1;
547 
548 	via_flush_write_combine();
549 	(void) *(volatile uint32_t *)dev_priv->last_pause_ptr;
550 
551 	via_write(dev_priv, VIA_REG_TRANSET, (HC_ParaType_PreCR << 16));
552 	via_write(dev_priv, VIA_REG_TRANSPACE, command);
553 	via_write(dev_priv, VIA_REG_TRANSPACE, start_addr_lo);
554 	via_write(dev_priv, VIA_REG_TRANSPACE, end_addr_lo);
555 
556 	via_write(dev_priv, VIA_REG_TRANSPACE, pause_addr_hi);
557 	via_write(dev_priv, VIA_REG_TRANSPACE, pause_addr_lo);
558 	wmb();
559 	via_write(dev_priv, VIA_REG_TRANSPACE, command | HC_HAGPCMNT_MASK);
560 	via_read(dev_priv, VIA_REG_TRANSPACE);
561 
562 	dev_priv->dma_diff = 0;
563 
564 	count = 10000000;
565 	while (!(via_read(dev_priv, 0x41c) & 0x80000000) && count--);
566 
567 	reader = *(dev_priv->hw_addr_ptr);
568 	ptr = ((volatile char *)dev_priv->last_pause_ptr - dev_priv->dma_ptr) +
569 	    dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr + 4;
570 
571 	/*
572 	 * This is the difference between where we tell the
573 	 * command reader to pause and where it actually pauses.
574 	 * This differs between hw implementation so we need to
575 	 * detect it.
576 	 */
577 
578 	dev_priv->dma_diff = ptr - reader;
579 }
580 
via_pad_cache(drm_via_private_t * dev_priv,int qwords)581 static void via_pad_cache(drm_via_private_t *dev_priv, int qwords)
582 {
583 	uint32_t *vb;
584 
585 	via_cmdbuf_wait(dev_priv, qwords + 2);
586 	vb = via_get_dma(dev_priv);
587 	VIA_OUT_RING_QW(HC_HEADER2, HC_ParaType_NotTex << 16);
588 	via_align_buffer(dev_priv, vb, qwords);
589 }
590 
via_dummy_bitblt(drm_via_private_t * dev_priv)591 static inline void via_dummy_bitblt(drm_via_private_t *dev_priv)
592 {
593 	uint32_t *vb = via_get_dma(dev_priv);
594 	SetReg2DAGP(0x0C, (0 | (0 << 16)));
595 	SetReg2DAGP(0x10, 0 | (0 << 16));
596 	SetReg2DAGP(0x0, 0x1 | 0x2000 | 0xAA000000);
597 }
598 
via_cmdbuf_jump(drm_via_private_t * dev_priv)599 static void via_cmdbuf_jump(drm_via_private_t *dev_priv)
600 {
601 	uint32_t pause_addr_lo, pause_addr_hi;
602 	uint32_t jump_addr_lo, jump_addr_hi;
603 	volatile uint32_t *last_pause_ptr;
604 	uint32_t dma_low_save1, dma_low_save2;
605 
606 	via_align_cmd(dev_priv, HC_HAGPBpID_JUMP, 0, &jump_addr_hi,
607 		      &jump_addr_lo, 0);
608 
609 	dev_priv->dma_wrap = dev_priv->dma_low;
610 
611 	/*
612 	 * Wrap command buffer to the beginning.
613 	 */
614 
615 	dev_priv->dma_low = 0;
616 	if (via_cmdbuf_wait(dev_priv, CMDBUF_ALIGNMENT_SIZE) != 0)
617 		DRM_ERROR("via_cmdbuf_jump failed\n");
618 
619 	via_dummy_bitblt(dev_priv);
620 	via_dummy_bitblt(dev_priv);
621 
622 	last_pause_ptr =
623 	    via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0, &pause_addr_hi,
624 			  &pause_addr_lo, 0) - 1;
625 	via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0, &pause_addr_hi,
626 		      &pause_addr_lo, 0);
627 
628 	*last_pause_ptr = pause_addr_lo;
629 	dma_low_save1 = dev_priv->dma_low;
630 
631 	/*
632 	 * Now, set a trap that will pause the regulator if it tries to rerun the old
633 	 * command buffer. (Which may happen if via_hook_segment detecs a command regulator pause
634 	 * and reissues the jump command over PCI, while the regulator has already taken the jump
635 	 * and actually paused at the current buffer end).
636 	 * There appears to be no other way to detect this condition, since the hw_addr_pointer
637 	 * does not seem to get updated immediately when a jump occurs.
638 	 */
639 
640 	last_pause_ptr =
641 		via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0, &pause_addr_hi,
642 			      &pause_addr_lo, 0) - 1;
643 	via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0, &pause_addr_hi,
644 		      &pause_addr_lo, 0);
645 	*last_pause_ptr = pause_addr_lo;
646 
647 	dma_low_save2 = dev_priv->dma_low;
648 	dev_priv->dma_low = dma_low_save1;
649 	via_hook_segment(dev_priv, jump_addr_hi, jump_addr_lo, 0);
650 	dev_priv->dma_low = dma_low_save2;
651 	via_hook_segment(dev_priv, pause_addr_hi, pause_addr_lo, 0);
652 }
653 
654 
via_cmdbuf_rewind(drm_via_private_t * dev_priv)655 static void via_cmdbuf_rewind(drm_via_private_t *dev_priv)
656 {
657 	via_cmdbuf_jump(dev_priv);
658 }
659 
via_cmdbuf_flush(drm_via_private_t * dev_priv,uint32_t cmd_type)660 static void via_cmdbuf_flush(drm_via_private_t *dev_priv, uint32_t cmd_type)
661 {
662 	uint32_t pause_addr_lo, pause_addr_hi;
663 
664 	via_align_cmd(dev_priv, cmd_type, 0, &pause_addr_hi, &pause_addr_lo, 0);
665 	via_hook_segment(dev_priv, pause_addr_hi, pause_addr_lo, 0);
666 }
667 
via_cmdbuf_pause(drm_via_private_t * dev_priv)668 static void via_cmdbuf_pause(drm_via_private_t *dev_priv)
669 {
670 	via_cmdbuf_flush(dev_priv, HC_HAGPBpID_PAUSE);
671 }
672 
via_cmdbuf_reset(drm_via_private_t * dev_priv)673 static void via_cmdbuf_reset(drm_via_private_t *dev_priv)
674 {
675 	via_cmdbuf_flush(dev_priv, HC_HAGPBpID_STOP);
676 	via_wait_idle(dev_priv);
677 }
678 
679 /*
680  * User interface to the space and lag functions.
681  */
682 
via_cmdbuf_size(struct drm_device * dev,void * data,struct drm_file * file_priv)683 static int via_cmdbuf_size(struct drm_device *dev, void *data, struct drm_file *file_priv)
684 {
685 	drm_via_cmdbuf_size_t *d_siz = data;
686 	int ret = 0;
687 	uint32_t tmp_size, count;
688 	drm_via_private_t *dev_priv;
689 
690 	DRM_DEBUG("\n");
691 	LOCK_TEST_WITH_RETURN(dev, file_priv);
692 
693 	dev_priv = (drm_via_private_t *) dev->dev_private;
694 
695 	if (dev_priv->ring.virtual_start == NULL) {
696 		DRM_ERROR("called without initializing AGP ring buffer.\n");
697 		return -EFAULT;
698 	}
699 
700 	count = 1000000;
701 	tmp_size = d_siz->size;
702 	switch (d_siz->func) {
703 	case VIA_CMDBUF_SPACE:
704 		while (((tmp_size = via_cmdbuf_space(dev_priv)) < d_siz->size)
705 		       && --count) {
706 			if (!d_siz->wait)
707 				break;
708 		}
709 		if (!count) {
710 			DRM_ERROR("VIA_CMDBUF_SPACE timed out.\n");
711 			ret = -EAGAIN;
712 		}
713 		break;
714 	case VIA_CMDBUF_LAG:
715 		while (((tmp_size = via_cmdbuf_lag(dev_priv)) > d_siz->size)
716 		       && --count) {
717 			if (!d_siz->wait)
718 				break;
719 		}
720 		if (!count) {
721 			DRM_ERROR("VIA_CMDBUF_LAG timed out.\n");
722 			ret = -EAGAIN;
723 		}
724 		break;
725 	default:
726 		ret = -EFAULT;
727 	}
728 	d_siz->size = tmp_size;
729 
730 	return ret;
731 }
732 
733 const struct drm_ioctl_desc via_ioctls[] = {
734 	DRM_IOCTL_DEF_DRV(VIA_ALLOCMEM, via_mem_alloc, DRM_AUTH),
735 	DRM_IOCTL_DEF_DRV(VIA_FREEMEM, via_mem_free, DRM_AUTH),
736 	DRM_IOCTL_DEF_DRV(VIA_AGP_INIT, via_agp_init, DRM_AUTH|DRM_MASTER),
737 	DRM_IOCTL_DEF_DRV(VIA_FB_INIT, via_fb_init, DRM_AUTH|DRM_MASTER),
738 	DRM_IOCTL_DEF_DRV(VIA_MAP_INIT, via_map_init, DRM_AUTH|DRM_MASTER),
739 	DRM_IOCTL_DEF_DRV(VIA_DEC_FUTEX, via_decoder_futex, DRM_AUTH),
740 	DRM_IOCTL_DEF_DRV(VIA_DMA_INIT, via_dma_init, DRM_AUTH),
741 	DRM_IOCTL_DEF_DRV(VIA_CMDBUFFER, via_cmdbuffer, DRM_AUTH),
742 	DRM_IOCTL_DEF_DRV(VIA_FLUSH, via_flush_ioctl, DRM_AUTH),
743 	DRM_IOCTL_DEF_DRV(VIA_PCICMD, via_pci_cmdbuffer, DRM_AUTH),
744 	DRM_IOCTL_DEF_DRV(VIA_CMDBUF_SIZE, via_cmdbuf_size, DRM_AUTH),
745 	DRM_IOCTL_DEF_DRV(VIA_WAIT_IRQ, via_wait_irq, DRM_AUTH),
746 	DRM_IOCTL_DEF_DRV(VIA_DMA_BLIT, via_dma_blit, DRM_AUTH),
747 	DRM_IOCTL_DEF_DRV(VIA_BLIT_SYNC, via_dma_blit_sync, DRM_AUTH)
748 };
749 
750 int via_max_ioctl = ARRAY_SIZE(via_ioctls);
751