xref: /netbsd-src/sys/external/bsd/drm2/dist/drm/amd/amdgpu/amdgpu_gart.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /*	$NetBSD: amdgpu_gart.c,v 1.8 2021/12/24 11:19:55 riastradh Exp $	*/
2 
3 /*
4  * Copyright 2008 Advanced Micro Devices, Inc.
5  * Copyright 2008 Red Hat Inc.
6  * Copyright 2009 Jerome Glisse.
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a
9  * copy of this software and associated documentation files (the "Software"),
10  * to deal in the Software without restriction, including without limitation
11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12  * and/or sell copies of the Software, and to permit persons to whom the
13  * Software is furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
22  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
23  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24  * OTHER DEALINGS IN THE SOFTWARE.
25  *
26  * Authors: Dave Airlie
27  *          Alex Deucher
28  *          Jerome Glisse
29  */
30 
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: amdgpu_gart.c,v 1.8 2021/12/24 11:19:55 riastradh Exp $");
33 
34 #include <linux/pci.h>
35 #include <linux/vmalloc.h>
36 
37 #include <drm/amdgpu_drm.h>
38 #ifdef CONFIG_X86
39 #include <asm/set_memory.h>
40 #endif
41 #include "amdgpu.h"
42 
43 /*
44  * GART
45  * The GART (Graphics Aperture Remapping Table) is an aperture
46  * in the GPU's address space.  System pages can be mapped into
47  * the aperture and look like contiguous pages from the GPU's
48  * perspective.  A page table maps the pages in the aperture
49  * to the actual backing pages in system memory.
50  *
51  * Radeon GPUs support both an internal GART, as described above,
52  * and AGP.  AGP works similarly, but the GART table is configured
53  * and maintained by the northbridge rather than the driver.
54  * Radeon hw has a separate AGP aperture that is programmed to
55  * point to the AGP aperture provided by the northbridge and the
56  * requests are passed through to the northbridge aperture.
57  * Both AGP and internal GART can be used at the same time, however
58  * that is not currently supported by the driver.
59  *
60  * This file handles the common internal GART management.
61  */
62 
63 /*
64  * Common GART table functions.
65  */
66 
67 /**
68  * amdgpu_dummy_page_init - init dummy page used by the driver
69  *
70  * @adev: amdgpu_device pointer
71  *
72  * Allocate the dummy page used by the driver (all asics).
73  * This dummy page is used by the driver as a filler for gart entries
74  * when pages are taken out of the GART
75  * Returns 0 on sucess, -ENOMEM on failure.
76  */
77 static int amdgpu_gart_dummy_page_init(struct amdgpu_device *adev)
78 {
79 #ifdef __NetBSD__
80 	int rsegs;
81 	int error;
82 
83 	/* XXX Can this be called more than once??  */
84 	if (adev->dummy_page_map != NULL)
85 		return 0;
86 
87 	error = bus_dmamem_alloc(adev->ddev->dmat, PAGE_SIZE, PAGE_SIZE, 0,
88 	    &adev->dummy_page_seg, 1, &rsegs, BUS_DMA_WAITOK);
89 	if (error)
90 		goto fail0;
91 	KASSERT(rsegs == 1);
92 	error = bus_dmamap_create(adev->ddev->dmat, PAGE_SIZE, 1, PAGE_SIZE, 0,
93 	    BUS_DMA_WAITOK, &adev->dummy_page_map);
94 	if (error)
95 		goto fail1;
96 	error = bus_dmamap_load_raw(adev->ddev->dmat, adev->dummy_page_map,
97 	    &adev->dummy_page_seg, 1, PAGE_SIZE, BUS_DMA_WAITOK);
98 	if (error)
99 		goto fail2;
100 
101 	/* Success!  */
102 	adev->dummy_page_addr = adev->dummy_page_map->dm_segs[0].ds_addr;
103 	return 0;
104 
105 fail3: __unused
106 	bus_dmamap_unload(adev->ddev->dmat, adev->dummy_page_map);
107 fail2:	bus_dmamap_destroy(adev->ddev->dmat, adev->dummy_page_map);
108 fail1:	bus_dmamem_free(adev->ddev->dmat, &adev->dummy_page_seg, 1);
109 fail0:	KASSERT(error);
110 	adev->dummy_page_map = NULL;
111 	adev->dummy_page_addr = 0; /* paranoia */
112 	/* XXX errno NetBSD->Linux */
113 	return -error;
114 #else  /* __NetBSD__ */
115 	struct page *dummy_page = ttm_bo_glob.dummy_read_page;
116 
117 	if (adev->dummy_page_addr)
118 		return 0;
119 	adev->dummy_page_addr = pci_map_page(adev->pdev, dummy_page, 0,
120 					     PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
121 	if (pci_dma_mapping_error(adev->pdev, adev->dummy_page_addr)) {
122 		dev_err(&adev->pdev->dev, "Failed to DMA MAP the dummy page\n");
123 		adev->dummy_page_addr = 0;
124 		return -ENOMEM;
125 	}
126 	return 0;
127 #endif	/* __NetBSD__ */
128 }
129 
130 /**
131  * amdgpu_dummy_page_fini - free dummy page used by the driver
132  *
133  * @adev: amdgpu_device pointer
134  *
135  * Frees the dummy page used by the driver (all asics).
136  */
137 static void amdgpu_gart_dummy_page_fini(struct amdgpu_device *adev)
138 {
139 	if (!adev->dummy_page_addr)
140 		return;
141 #ifdef __NetBSD__
142 	bus_dmamap_unload(adev->ddev->dmat, adev->dummy_page_map);
143 	bus_dmamap_destroy(adev->ddev->dmat, adev->dummy_page_map);
144 	bus_dmamem_free(adev->ddev->dmat, &adev->dummy_page_seg, 1);
145 	adev->dummy_page_map = NULL;
146 #else
147 	pci_unmap_page(adev->pdev, adev->dummy_page_addr,
148 		       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
149 #endif
150 	adev->dummy_page_addr = 0;
151 }
152 
153 /**
154  * amdgpu_gart_table_vram_alloc - allocate vram for gart page table
155  *
156  * @adev: amdgpu_device pointer
157  *
158  * Allocate video memory for GART page table
159  * (pcie r4xx, r5xx+).  These asics require the
160  * gart table to be in video memory.
161  * Returns 0 for success, error for failure.
162  */
163 int amdgpu_gart_table_vram_alloc(struct amdgpu_device *adev)
164 {
165 	int r;
166 
167 	if (adev->gart.bo == NULL) {
168 		struct amdgpu_bo_param bp;
169 
170 		memset(&bp, 0, sizeof(bp));
171 		bp.size = adev->gart.table_size;
172 		bp.byte_align = PAGE_SIZE;
173 		bp.domain = AMDGPU_GEM_DOMAIN_VRAM;
174 		bp.flags = AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED |
175 			AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS;
176 		bp.type = ttm_bo_type_kernel;
177 		bp.resv = NULL;
178 		r = amdgpu_bo_create(adev, &bp, &adev->gart.bo);
179 		if (r) {
180 			return r;
181 		}
182 	}
183 	return 0;
184 }
185 
186 /**
187  * amdgpu_gart_table_vram_pin - pin gart page table in vram
188  *
189  * @adev: amdgpu_device pointer
190  *
191  * Pin the GART page table in vram so it will not be moved
192  * by the memory manager (pcie r4xx, r5xx+).  These asics require the
193  * gart table to be in video memory.
194  * Returns 0 for success, error for failure.
195  */
196 int amdgpu_gart_table_vram_pin(struct amdgpu_device *adev)
197 {
198 	int r;
199 
200 	r = amdgpu_bo_reserve(adev->gart.bo, false);
201 	if (unlikely(r != 0))
202 		return r;
203 	r = amdgpu_bo_pin(adev->gart.bo, AMDGPU_GEM_DOMAIN_VRAM);
204 	if (r) {
205 		amdgpu_bo_unreserve(adev->gart.bo);
206 		return r;
207 	}
208 	r = amdgpu_bo_kmap(adev->gart.bo, &adev->gart.ptr);
209 	if (r)
210 		amdgpu_bo_unpin(adev->gart.bo);
211 	amdgpu_bo_unreserve(adev->gart.bo);
212 	return r;
213 }
214 
215 /**
216  * amdgpu_gart_table_vram_unpin - unpin gart page table in vram
217  *
218  * @adev: amdgpu_device pointer
219  *
220  * Unpin the GART page table in vram (pcie r4xx, r5xx+).
221  * These asics require the gart table to be in video memory.
222  */
223 void amdgpu_gart_table_vram_unpin(struct amdgpu_device *adev)
224 {
225 	int r;
226 
227 	if (adev->gart.bo == NULL) {
228 		return;
229 	}
230 	r = amdgpu_bo_reserve(adev->gart.bo, true);
231 	if (likely(r == 0)) {
232 		amdgpu_bo_kunmap(adev->gart.bo);
233 		amdgpu_bo_unpin(adev->gart.bo);
234 		amdgpu_bo_unreserve(adev->gart.bo);
235 		adev->gart.ptr = NULL;
236 	}
237 }
238 
239 /**
240  * amdgpu_gart_table_vram_free - free gart page table vram
241  *
242  * @adev: amdgpu_device pointer
243  *
244  * Free the video memory used for the GART page table
245  * (pcie r4xx, r5xx+).  These asics require the gart table to
246  * be in video memory.
247  */
248 void amdgpu_gart_table_vram_free(struct amdgpu_device *adev)
249 {
250 	if (adev->gart.bo == NULL) {
251 		return;
252 	}
253 	amdgpu_bo_unref(&adev->gart.bo);
254 }
255 
256 #ifdef __NetBSD__
257 static void
258 amdgpu_gart_pre_update(struct amdgpu_device *adev, unsigned gpu_pgstart,
259     unsigned gpu_npages)
260 {
261 
262 	if (adev->gart.ag_table_map != NULL) {
263 		const unsigned entsize =
264 		    adev->gart.table_size / adev->gart.num_gpu_pages;
265 
266 		bus_dmamap_sync(adev->ddev->dmat, adev->gart.ag_table_map,
267 		    gpu_pgstart*entsize, gpu_npages*entsize,
268 		    BUS_DMASYNC_POSTWRITE);
269 	}
270 }
271 
272 static void
273 amdgpu_gart_post_update(struct amdgpu_device *adev, unsigned gpu_pgstart,
274     unsigned gpu_npages)
275 {
276 	unsigned i;
277 
278 	if (adev->gart.ag_table_map != NULL) {
279 		const unsigned entsize =
280 		    adev->gart.table_size / adev->gart.num_gpu_pages;
281 
282 		bus_dmamap_sync(adev->ddev->dmat, adev->gart.ag_table_map,
283 		    gpu_pgstart*entsize, gpu_npages*entsize,
284 		    BUS_DMASYNC_PREWRITE);
285 	}
286 	mb();			/* XXX why is bus_dmamap_sync not enough? */
287 	amdgpu_asic_flush_hdp(adev, NULL);
288 	for (i = 0; i < adev->num_vmhubs; i++)
289 		amdgpu_gmc_flush_gpu_tlb(adev, 0, i, 0);
290 }
291 #endif
292 
293 /*
294  * Common gart functions.
295  */
296 #ifdef __NetBSD__
297 int
298 amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t gpu_start,
299     unsigned npages)
300 {
301 	const unsigned gpu_per_cpu = AMDGPU_GPU_PAGES_IN_CPU_PAGE;
302 	const unsigned gpu_npages = (npages * gpu_per_cpu);
303 	const uint64_t gpu_pgstart = (gpu_start / AMDGPU_GPU_PAGE_SIZE);
304 	const uint64_t pgstart __diagused = (gpu_pgstart / gpu_per_cpu);
305 	uint64_t pgno, gpu_pgno;
306 	uint32_t flags = AMDGPU_PTE_SYSTEM;
307 
308 	KASSERT(pgstart == (gpu_start / PAGE_SIZE));
309 	KASSERT(npages <= adev->gart.num_cpu_pages);
310 	KASSERT(gpu_npages <= adev->gart.num_cpu_pages);
311 
312 	if (!adev->gart.ready) {
313 		WARN(1, "trying to bind memory to uninitialized GART !\n");
314 		return -EINVAL;
315 	}
316 
317 	amdgpu_gart_pre_update(adev, gpu_pgstart, gpu_npages);
318 	for (pgno = 0; pgno < npages; pgno++) {
319 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
320 		adev->gart.pages[pgstart + pgno] = NULL;
321 #endif
322 
323 		if (adev->gart.ptr == NULL)
324 			continue;
325 		for (gpu_pgno = 0; gpu_pgno < gpu_per_cpu; gpu_pgno++) {
326 			amdgpu_gmc_set_pte_pde(adev, adev->gart.ptr,
327 			    gpu_pgstart + gpu_per_cpu*pgno + gpu_pgno,
328 			    adev->dummy_page_addr, flags);
329 		}
330 	}
331 	amdgpu_gart_post_update(adev, gpu_pgstart, gpu_npages);
332 
333 	return 0;
334 }
335 #else  /* __NetBSD__ */
336 /**
337  * amdgpu_gart_unbind - unbind pages from the gart page table
338  *
339  * @adev: amdgpu_device pointer
340  * @offset: offset into the GPU's gart aperture
341  * @pages: number of pages to unbind
342  *
343  * Unbinds the requested pages from the gart page table and
344  * replaces them with the dummy page (all asics).
345  * Returns 0 for success, -EINVAL for failure.
346  */
347 int amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
348 			int pages)
349 {
350 	unsigned t;
351 	unsigned p;
352 	int i, j;
353 	u64 page_base;
354 	/* Starting from VEGA10, system bit must be 0 to mean invalid. */
355 	uint64_t flags = 0;
356 
357 	if (!adev->gart.ready) {
358 		WARN(1, "trying to unbind memory from uninitialized GART !\n");
359 		return -EINVAL;
360 	}
361 
362 	t = offset / AMDGPU_GPU_PAGE_SIZE;
363 	p = t / AMDGPU_GPU_PAGES_IN_CPU_PAGE;
364 	for (i = 0; i < pages; i++, p++) {
365 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
366 		adev->gart.pages[p] = NULL;
367 #endif
368 		page_base = adev->dummy_page_addr;
369 		if (!adev->gart.ptr)
370 			continue;
371 
372 		for (j = 0; j < AMDGPU_GPU_PAGES_IN_CPU_PAGE; j++, t++) {
373 			amdgpu_gmc_set_pte_pde(adev, adev->gart.ptr,
374 					       t, page_base, flags);
375 			page_base += AMDGPU_GPU_PAGE_SIZE;
376 		}
377 	}
378 	mb();
379 	amdgpu_asic_flush_hdp(adev, NULL);
380 	for (i = 0; i < adev->num_vmhubs; i++)
381 		amdgpu_gmc_flush_gpu_tlb(adev, 0, i, 0);
382 
383 	return 0;
384 }
385 #endif	/* __NetBSD__ */
386 
387 /**
388  * amdgpu_gart_map - map dma_addresses into GART entries
389  *
390  * @adev: amdgpu_device pointer
391  * @offset: offset into the GPU's gart aperture
392  * @pages: number of pages to bind
393  * @dma_addr: DMA addresses of pages
394  * @flags: page table entry flags
395  * @dst: CPU address of the gart table
396  *
397  * Map the dma_addresses into GART entries (all asics).
398  * Returns 0 for success, -EINVAL for failure.
399  */
400 #ifdef __NetBSD__
401 int amdgpu_gart_map(struct amdgpu_device *adev, uint64_t gpu_start,
402     unsigned npages, bus_size_t map_start, bus_dmamap_t dmamap, uint32_t flags,
403     void *dst)
404 {
405 	bus_size_t seg_off = 0;
406 	unsigned i, j, t;
407 
408 	CTASSERT(AMDGPU_GPU_PAGE_SIZE <= PAGE_SIZE);
409 	CTASSERT((PAGE_SIZE % AMDGPU_GPU_PAGE_SIZE) == 0);
410 
411 	KASSERT((gpu_start & (PAGE_SIZE - 1)) == 0);
412 
413 	if (!adev->gart.ready) {
414 		WARN(1, "trying to bind memory to uninitialized GART !\n");
415 		return -EINVAL;
416 	}
417 
418 	for (i = 0; i < dmamap->dm_nsegs; i++) {
419 		KASSERT((dmamap->dm_segs[i].ds_len & (PAGE_SIZE - 1)) == 0);
420 		if (map_start == 0)
421 			break;
422 		if (map_start < dmamap->dm_segs[i].ds_len) {
423 			seg_off = map_start;
424 			break;
425 		}
426 		map_start -= dmamap->dm_segs[i].ds_len;
427 	}
428 	KASSERT(i < dmamap->dm_nsegs);
429 
430 	t = gpu_start / AMDGPU_GPU_PAGE_SIZE;
431 
432 	for (i = 0; npages --> 0;) {
433 		KASSERT(i < dmamap->dm_nsegs);
434 		for (j = 0; j < AMDGPU_GPU_PAGES_IN_CPU_PAGE; j++) {
435 			amdgpu_gmc_set_pte_pde(adev, dst, t,
436 			    dmamap->dm_segs[i].ds_addr + seg_off, flags);
437 			seg_off += AMDGPU_GPU_PAGE_SIZE;
438 			if (seg_off == dmamap->dm_segs[i].ds_len) {
439 				i++;
440 				seg_off = 0;
441 			}
442 			KASSERT(seg_off < dmamap->dm_segs[i].ds_len);
443 		}
444 	}
445 
446 	return 0;
447 }
448 #else
449 int amdgpu_gart_map(struct amdgpu_device *adev, uint64_t offset,
450 		    int pages, dma_addr_t *dma_addr, uint64_t flags,
451 		    void *dst)
452 {
453 	uint64_t page_base;
454 	unsigned i, j, t;
455 
456 	if (!adev->gart.ready) {
457 		WARN(1, "trying to bind memory to uninitialized GART !\n");
458 		return -EINVAL;
459 	}
460 
461 	t = offset / AMDGPU_GPU_PAGE_SIZE;
462 
463 	for (i = 0; i < pages; i++) {
464 		page_base = dma_addr[i];
465 		for (j = 0; j < AMDGPU_GPU_PAGES_IN_CPU_PAGE; j++, t++) {
466 			amdgpu_gmc_set_pte_pde(adev, dst, t, page_base, flags);
467 			page_base += AMDGPU_GPU_PAGE_SIZE;
468 		}
469 	}
470 	return 0;
471 }
472 #endif	/* __NetBSD__ */
473 
474 #ifdef __NetBSD__
475 int
476 amdgpu_gart_bind(struct amdgpu_device *adev, uint64_t gpu_start,
477     unsigned npages, struct page **pages, bus_dmamap_t dmamap, uint32_t flags)
478 {
479 	const unsigned gpu_per_cpu = AMDGPU_GPU_PAGES_IN_CPU_PAGE;
480 	const unsigned gpu_npages = (npages * gpu_per_cpu);
481 	const uint64_t gpu_pgstart = (gpu_start / AMDGPU_GPU_PAGE_SIZE);
482 	const uint64_t pgstart __diagused = (gpu_pgstart / gpu_per_cpu);
483 	uint64_t pgno, gpu_pgno;
484 
485 	KASSERT(pgstart == (gpu_start / PAGE_SIZE));
486 	KASSERT(npages == dmamap->dm_nsegs);
487 	KASSERT(npages <= adev->gart.num_cpu_pages);
488 	KASSERT(gpu_npages <= adev->gart.num_cpu_pages);
489 
490 	if (!adev->gart.ready) {
491 		WARN(1, "trying to bind memory to uninitialized GART !\n");
492 		return -EINVAL;
493 	}
494 
495 	amdgpu_gart_pre_update(adev, gpu_pgstart, gpu_npages);
496 	for (pgno = 0; pgno < npages; pgno++) {
497 		const bus_addr_t addr = dmamap->dm_segs[pgno].ds_addr;
498 
499 		KASSERT(dmamap->dm_segs[pgno].ds_len == PAGE_SIZE);
500 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
501 		adev->gart.pages[pgstart + pgno] = NULL;
502 #endif
503 
504 		if (adev->gart.ptr == NULL)
505 			continue;
506 
507 		for (gpu_pgno = 0; gpu_pgno < gpu_per_cpu; gpu_pgno++) {
508 			amdgpu_gmc_set_pte_pde(adev, adev->gart.ptr,
509 			    gpu_pgstart + gpu_per_cpu*pgno + gpu_pgno,
510 			    addr + gpu_pgno*AMDGPU_GPU_PAGE_SIZE, flags);
511 		}
512 	}
513 	amdgpu_gart_post_update(adev, gpu_pgstart, gpu_npages);
514 
515 	return 0;
516 }
517 #else  /* __NetBSD__ */
518 /**
519  * amdgpu_gart_bind - bind pages into the gart page table
520  *
521  * @adev: amdgpu_device pointer
522  * @offset: offset into the GPU's gart aperture
523  * @pages: number of pages to bind
524  * @pagelist: pages to bind
525  * @dma_addr: DMA addresses of pages
526  * @flags: page table entry flags
527  *
528  * Binds the requested pages to the gart page table
529  * (all asics).
530  * Returns 0 for success, -EINVAL for failure.
531  */
532 int amdgpu_gart_bind(struct amdgpu_device *adev, uint64_t offset,
533 		     int pages, struct page **pagelist, dma_addr_t *dma_addr,
534 		     uint64_t flags)
535 {
536 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
537 	unsigned t,p;
538 #endif
539 	int r, i;
540 
541 	if (!adev->gart.ready) {
542 		WARN(1, "trying to bind memory to uninitialized GART !\n");
543 		return -EINVAL;
544 	}
545 
546 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
547 	t = offset / AMDGPU_GPU_PAGE_SIZE;
548 	p = t / AMDGPU_GPU_PAGES_IN_CPU_PAGE;
549 	for (i = 0; i < pages; i++, p++)
550 		adev->gart.pages[p] = pagelist ? pagelist[i] : NULL;
551 #endif
552 
553 	if (!adev->gart.ptr)
554 		return 0;
555 
556 	r = amdgpu_gart_map(adev, offset, pages, dma_addr, flags,
557 		    adev->gart.ptr);
558 	if (r)
559 		return r;
560 
561 	mb();
562 	amdgpu_asic_flush_hdp(adev, NULL);
563 	for (i = 0; i < adev->num_vmhubs; i++)
564 		amdgpu_gmc_flush_gpu_tlb(adev, 0, i, 0);
565 	return 0;
566 }
567 #endif
568 
569 /**
570  * amdgpu_gart_init - init the driver info for managing the gart
571  *
572  * @adev: amdgpu_device pointer
573  *
574  * Allocate the dummy page and init the gart driver info (all asics).
575  * Returns 0 for success, error for failure.
576  */
577 int amdgpu_gart_init(struct amdgpu_device *adev)
578 {
579 	int r;
580 
581 	if (adev->dummy_page_addr)
582 		return 0;
583 
584 	/* We need PAGE_SIZE >= AMDGPU_GPU_PAGE_SIZE */
585 	if (PAGE_SIZE < AMDGPU_GPU_PAGE_SIZE) {
586 		DRM_ERROR("Page size is smaller than GPU page size!\n");
587 		return -EINVAL;
588 	}
589 	r = amdgpu_gart_dummy_page_init(adev);
590 	if (r)
591 		return r;
592 	/* Compute table size */
593 	adev->gart.num_cpu_pages = adev->gmc.gart_size / PAGE_SIZE;
594 	adev->gart.num_gpu_pages = adev->gmc.gart_size / AMDGPU_GPU_PAGE_SIZE;
595 	DRM_INFO("GART: num cpu pages %u, num gpu pages %u\n",
596 		 adev->gart.num_cpu_pages, adev->gart.num_gpu_pages);
597 
598 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
599 	/* Allocate pages table */
600 	adev->gart.pages = vzalloc(array_size(sizeof(void *),
601 					      adev->gart.num_cpu_pages));
602 	if (adev->gart.pages == NULL)
603 		return -ENOMEM;
604 #endif
605 
606 	return 0;
607 }
608 
609 /**
610  * amdgpu_gart_fini - tear down the driver info for managing the gart
611  *
612  * @adev: amdgpu_device pointer
613  *
614  * Tear down the gart driver info and free the dummy page (all asics).
615  */
616 void amdgpu_gart_fini(struct amdgpu_device *adev)
617 {
618 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
619 	vfree(adev->gart.pages);
620 	adev->gart.pages = NULL;
621 #endif
622 	amdgpu_gart_dummy_page_fini(adev);
623 }
624