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radeon_gart.c revision 1.5.32.1
      1 /*	$NetBSD: radeon_gart.c,v 1.5.32.1 2019/06/10 22:08:26 christos 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 #include <sys/cdefs.h>
     31 __KERNEL_RCSID(0, "$NetBSD: radeon_gart.c,v 1.5.32.1 2019/06/10 22:08:26 christos Exp $");
     32 
     33 #include <drm/drmP.h>
     34 #include <drm/radeon_drm.h>
     35 #include "radeon.h"
     36 
     37 /*
     38  * GART
     39  * The GART (Graphics Aperture Remapping Table) is an aperture
     40  * in the GPU's address space.  System pages can be mapped into
     41  * the aperture and look like contiguous pages from the GPU's
     42  * perspective.  A page table maps the pages in the aperture
     43  * to the actual backing pages in system memory.
     44  *
     45  * Radeon GPUs support both an internal GART, as described above,
     46  * and AGP.  AGP works similarly, but the GART table is configured
     47  * and maintained by the northbridge rather than the driver.
     48  * Radeon hw has a separate AGP aperture that is programmed to
     49  * point to the AGP aperture provided by the northbridge and the
     50  * requests are passed through to the northbridge aperture.
     51  * Both AGP and internal GART can be used at the same time, however
     52  * that is not currently supported by the driver.
     53  *
     54  * This file handles the common internal GART management.
     55  */
     56 
     57 /*
     58  * Common GART table functions.
     59  */
     60 /**
     61  * radeon_gart_table_ram_alloc - allocate system ram for gart page table
     62  *
     63  * @rdev: radeon_device pointer
     64  *
     65  * Allocate system memory for GART page table
     66  * (r1xx-r3xx, non-pcie r4xx, rs400).  These asics require the
     67  * gart table to be in system memory.
     68  * Returns 0 for success, -ENOMEM for failure.
     69  */
     70 int radeon_gart_table_ram_alloc(struct radeon_device *rdev)
     71 {
     72 #ifdef __NetBSD__
     73 	int rsegs;
     74 	int error;
     75 
     76 	error = bus_dmamem_alloc(rdev->ddev->dmat, rdev->gart.table_size,
     77 	    PAGE_SIZE, 0, &rdev->gart.rg_table_seg, 1, &rsegs, BUS_DMA_WAITOK);
     78 	if (error)
     79 		goto fail0;
     80 	KASSERT(rsegs == 1);
     81 	error = bus_dmamap_create(rdev->ddev->dmat, rdev->gart.table_size, 1,
     82 	    rdev->gart.table_size, 0, BUS_DMA_WAITOK,
     83 	    &rdev->gart.rg_table_map);
     84 	if (error)
     85 		goto fail1;
     86 	error = bus_dmamem_map(rdev->ddev->dmat, &rdev->gart.rg_table_seg, 1,
     87 	    rdev->gart.table_size, &rdev->gart.ptr,
     88 	    BUS_DMA_WAITOK|BUS_DMA_NOCACHE);
     89 	if (error)
     90 		goto fail2;
     91 	error = bus_dmamap_load(rdev->ddev->dmat, rdev->gart.rg_table_map,
     92 	    rdev->gart.ptr, rdev->gart.table_size, NULL, BUS_DMA_WAITOK);
     93 	if (error)
     94 		goto fail3;
     95 
     96 	/* Success!  */
     97 	rdev->gart.table_addr = rdev->gart.rg_table_map->dm_segs[0].ds_addr;
     98 	return 0;
     99 
    100 fail4: __unused
    101 	bus_dmamap_unload(rdev->ddev->dmat, rdev->gart.rg_table_map);
    102 fail3:	bus_dmamem_unmap(rdev->ddev->dmat, rdev->gart.ptr,
    103 	    rdev->gart.table_size);
    104 fail2:	bus_dmamap_destroy(rdev->ddev->dmat, rdev->gart.rg_table_map);
    105 fail1:	bus_dmamem_free(rdev->ddev->dmat, &rdev->gart.rg_table_seg, 1);
    106 fail0:	KASSERT(error);
    107 	/* XXX errno NetBSD->Linux */
    108 	return -error;
    109 #else
    110 	void *ptr;
    111 
    112 	ptr = pci_alloc_consistent(rdev->pdev, rdev->gart.table_size,
    113 				   &rdev->gart.table_addr);
    114 	if (ptr == NULL) {
    115 		return -ENOMEM;
    116 	}
    117 #ifdef CONFIG_X86
    118 	if (rdev->family == CHIP_RS400 || rdev->family == CHIP_RS480 ||
    119 	    rdev->family == CHIP_RS690 || rdev->family == CHIP_RS740) {
    120 		set_memory_uc((unsigned long)ptr,
    121 			      rdev->gart.table_size >> PAGE_SHIFT);
    122 	}
    123 #endif
    124 	rdev->gart.ptr = ptr;
    125 	memset((void *)rdev->gart.ptr, 0, rdev->gart.table_size);
    126 	return 0;
    127 #endif
    128 }
    129 
    130 /**
    131  * radeon_gart_table_ram_free - free system ram for gart page table
    132  *
    133  * @rdev: radeon_device pointer
    134  *
    135  * Free system memory for GART page table
    136  * (r1xx-r3xx, non-pcie r4xx, rs400).  These asics require the
    137  * gart table to be in system memory.
    138  */
    139 void radeon_gart_table_ram_free(struct radeon_device *rdev)
    140 {
    141 	if (rdev->gart.ptr == NULL) {
    142 		return;
    143 	}
    144 #ifdef __NetBSD__
    145 	bus_dmamap_unload(rdev->ddev->dmat, rdev->gart.rg_table_map);
    146 	bus_dmamem_unmap(rdev->ddev->dmat, rdev->gart.ptr,
    147 	    rdev->gart.table_size);
    148 	bus_dmamap_destroy(rdev->ddev->dmat, rdev->gart.rg_table_map);
    149 	bus_dmamem_free(rdev->ddev->dmat, &rdev->gart.rg_table_seg, 1);
    150 #else
    151 #ifdef CONFIG_X86
    152 	if (rdev->family == CHIP_RS400 || rdev->family == CHIP_RS480 ||
    153 	    rdev->family == CHIP_RS690 || rdev->family == CHIP_RS740) {
    154 		set_memory_wb((unsigned long)rdev->gart.ptr,
    155 			      rdev->gart.table_size >> PAGE_SHIFT);
    156 	}
    157 #endif
    158 	pci_free_consistent(rdev->pdev, rdev->gart.table_size,
    159 			    (void *)rdev->gart.ptr,
    160 			    rdev->gart.table_addr);
    161 	rdev->gart.ptr = NULL;
    162 	rdev->gart.table_addr = 0;
    163 #endif
    164 }
    165 
    166 /**
    167  * radeon_gart_table_vram_alloc - allocate vram for gart page table
    168  *
    169  * @rdev: radeon_device pointer
    170  *
    171  * Allocate video memory for GART page table
    172  * (pcie r4xx, r5xx+).  These asics require the
    173  * gart table to be in video memory.
    174  * Returns 0 for success, error for failure.
    175  */
    176 int radeon_gart_table_vram_alloc(struct radeon_device *rdev)
    177 {
    178 	int r;
    179 
    180 	if (rdev->gart.robj == NULL) {
    181 		r = radeon_bo_create(rdev, rdev->gart.table_size,
    182 				     PAGE_SIZE, true, RADEON_GEM_DOMAIN_VRAM,
    183 				     0, NULL, NULL, &rdev->gart.robj);
    184 		if (r) {
    185 			return r;
    186 		}
    187 	}
    188 	return 0;
    189 }
    190 
    191 /**
    192  * radeon_gart_table_vram_pin - pin gart page table in vram
    193  *
    194  * @rdev: radeon_device pointer
    195  *
    196  * Pin the GART page table in vram so it will not be moved
    197  * by the memory manager (pcie r4xx, r5xx+).  These asics require the
    198  * gart table to be in video memory.
    199  * Returns 0 for success, error for failure.
    200  */
    201 int radeon_gart_table_vram_pin(struct radeon_device *rdev)
    202 {
    203 	uint64_t gpu_addr;
    204 	int r;
    205 
    206 	r = radeon_bo_reserve(rdev->gart.robj, false);
    207 	if (unlikely(r != 0))
    208 		return r;
    209 	r = radeon_bo_pin(rdev->gart.robj,
    210 				RADEON_GEM_DOMAIN_VRAM, &gpu_addr);
    211 	if (r) {
    212 		radeon_bo_unreserve(rdev->gart.robj);
    213 		return r;
    214 	}
    215 	r = radeon_bo_kmap(rdev->gart.robj, &rdev->gart.ptr);
    216 	if (r)
    217 		radeon_bo_unpin(rdev->gart.robj);
    218 	radeon_bo_unreserve(rdev->gart.robj);
    219 	rdev->gart.table_addr = gpu_addr;
    220 
    221 	if (!r) {
    222 		int i;
    223 
    224 		/* We might have dropped some GART table updates while it wasn't
    225 		 * mapped, restore all entries
    226 		 */
    227 		for (i = 0; i < rdev->gart.num_gpu_pages; i++)
    228 			radeon_gart_set_page(rdev, i, rdev->gart.pages_entry[i]);
    229 		mb();
    230 		radeon_gart_tlb_flush(rdev);
    231 	}
    232 
    233 	return r;
    234 }
    235 
    236 /**
    237  * radeon_gart_table_vram_unpin - unpin gart page table in vram
    238  *
    239  * @rdev: radeon_device pointer
    240  *
    241  * Unpin the GART page table in vram (pcie r4xx, r5xx+).
    242  * These asics require the gart table to be in video memory.
    243  */
    244 void radeon_gart_table_vram_unpin(struct radeon_device *rdev)
    245 {
    246 	int r;
    247 
    248 	if (rdev->gart.robj == NULL) {
    249 		return;
    250 	}
    251 	r = radeon_bo_reserve(rdev->gart.robj, false);
    252 	if (likely(r == 0)) {
    253 		radeon_bo_kunmap(rdev->gart.robj);
    254 		radeon_bo_unpin(rdev->gart.robj);
    255 		radeon_bo_unreserve(rdev->gart.robj);
    256 		rdev->gart.ptr = NULL;
    257 	}
    258 }
    259 
    260 /**
    261  * radeon_gart_table_vram_free - free gart page table vram
    262  *
    263  * @rdev: radeon_device pointer
    264  *
    265  * Free the video memory used for the GART page table
    266  * (pcie r4xx, r5xx+).  These asics require the gart table to
    267  * be in video memory.
    268  */
    269 void radeon_gart_table_vram_free(struct radeon_device *rdev)
    270 {
    271 	if (rdev->gart.robj == NULL) {
    272 		return;
    273 	}
    274 	radeon_bo_unref(&rdev->gart.robj);
    275 }
    276 
    277 #ifdef __NetBSD__
    278 static void
    279 radeon_gart_pre_update(struct radeon_device *rdev, unsigned gpu_pgstart,
    280     unsigned gpu_npages)
    281 {
    282 
    283 	if (rdev->gart.rg_table_map != NULL) {
    284 		const unsigned entsize =
    285 		    rdev->gart.table_size / rdev->gart.num_gpu_pages;
    286 
    287 		bus_dmamap_sync(rdev->ddev->dmat, rdev->gart.rg_table_map,
    288 		    gpu_pgstart*entsize, gpu_npages*entsize,
    289 		    BUS_DMASYNC_POSTWRITE);
    290 	}
    291 }
    292 
    293 static void
    294 radeon_gart_post_update(struct radeon_device *rdev, unsigned gpu_pgstart,
    295     unsigned gpu_npages)
    296 {
    297 
    298 	if (rdev->gart.rg_table_map != NULL) {
    299 		const unsigned entsize =
    300 		    rdev->gart.table_size / rdev->gart.num_gpu_pages;
    301 
    302 		bus_dmamap_sync(rdev->ddev->dmat, rdev->gart.rg_table_map,
    303 		    gpu_pgstart*entsize, gpu_npages*entsize,
    304 		    BUS_DMASYNC_PREWRITE);
    305 	}
    306 	if (rdev->gart.ptr != NULL) {
    307 		membar_sync();		/* XXX overkill */
    308 		radeon_gart_tlb_flush(rdev);
    309 	}
    310 }
    311 #endif
    312 
    313 /*
    314  * Common gart functions.
    315  */
    316 #ifdef __NetBSD__
    317 void
    318 radeon_gart_unbind(struct radeon_device *rdev, unsigned gpu_start,
    319     unsigned npages)
    320 {
    321 	const unsigned gpu_per_cpu = (PAGE_SIZE / RADEON_GPU_PAGE_SIZE);
    322 	const unsigned gpu_npages = (npages * gpu_per_cpu);
    323 	const unsigned gpu_pgstart = (gpu_start / RADEON_GPU_PAGE_SIZE);
    324 	const unsigned pgstart = (gpu_pgstart / gpu_per_cpu);
    325 	unsigned pgno, gpu_pgno;
    326 
    327 	KASSERT(pgstart == (gpu_start / PAGE_SIZE));
    328 	KASSERT(npages <= rdev->gart.num_cpu_pages);
    329 	KASSERT(gpu_npages <= rdev->gart.num_cpu_pages);
    330 
    331 	if (!rdev->gart.ready) {
    332 		WARN(1, "trying to bind memory to uninitialized GART !\n");
    333 		return;
    334 	}
    335 
    336 	radeon_gart_pre_update(rdev, gpu_pgstart, gpu_npages);
    337 	for (pgno = 0; pgno < npages; pgno++) {
    338 		if (rdev->gart.pages[pgstart + pgno] == NULL)
    339 			continue;
    340 		rdev->gart.pages[pgstart + pgno] = NULL;
    341 		for (gpu_pgno = 0; gpu_pgno < gpu_per_cpu; gpu_pgno++) {
    342 			const unsigned t = gpu_pgstart + gpu_per_cpu*pgno +
    343 			    gpu_pgno;
    344 			rdev->gart.pages_entry[t] = rdev->dummy_page.entry;
    345 			if (rdev->gart.ptr == NULL)
    346 				continue;
    347 			radeon_gart_set_page(rdev, t, rdev->dummy_page.entry);
    348 		}
    349 	}
    350 	radeon_gart_post_update(rdev, gpu_pgstart, gpu_npages);
    351 }
    352 #else
    353 /**
    354  * radeon_gart_unbind - unbind pages from the gart page table
    355  *
    356  * @rdev: radeon_device pointer
    357  * @offset: offset into the GPU's gart aperture
    358  * @pages: number of pages to unbind
    359  *
    360  * Unbinds the requested pages from the gart page table and
    361  * replaces them with the dummy page (all asics).
    362  */
    363 void radeon_gart_unbind(struct radeon_device *rdev, unsigned offset,
    364 			int pages)
    365 {
    366 	unsigned t;
    367 	unsigned p;
    368 	int i, j;
    369 
    370 	if (!rdev->gart.ready) {
    371 		WARN(1, "trying to unbind memory from uninitialized GART !\n");
    372 		return;
    373 	}
    374 	t = offset / RADEON_GPU_PAGE_SIZE;
    375 	p = t / (PAGE_SIZE / RADEON_GPU_PAGE_SIZE);
    376 	for (i = 0; i < pages; i++, p++) {
    377 		if (rdev->gart.pages[p]) {
    378 			rdev->gart.pages[p] = NULL;
    379 			for (j = 0; j < (PAGE_SIZE / RADEON_GPU_PAGE_SIZE); j++, t++) {
    380 				rdev->gart.pages_entry[t] = rdev->dummy_page.entry;
    381 				if (rdev->gart.ptr) {
    382 					radeon_gart_set_page(rdev, t,
    383 							     rdev->dummy_page.entry);
    384 				}
    385 			}
    386 		}
    387 	}
    388 	if (rdev->gart.ptr) {
    389 		mb();
    390 		radeon_gart_tlb_flush(rdev);
    391 	}
    392 }
    393 #endif
    394 
    395 #ifdef __NetBSD__
    396 int
    397 radeon_gart_bind(struct radeon_device *rdev, unsigned gpu_start,
    398     unsigned npages, struct page **pages, bus_dmamap_t dmamap, uint32_t flags)
    399 {
    400 	const unsigned gpu_per_cpu = (PAGE_SIZE / RADEON_GPU_PAGE_SIZE);
    401 	const unsigned gpu_npages = (npages * gpu_per_cpu);
    402 	const unsigned gpu_pgstart = (gpu_start / RADEON_GPU_PAGE_SIZE);
    403 	const unsigned pgstart = (gpu_pgstart / gpu_per_cpu);
    404 	unsigned pgno, gpu_pgno;
    405 	uint64_t page_entry;
    406 
    407 	KASSERT(pgstart == (gpu_start / PAGE_SIZE));
    408 	KASSERT(npages == dmamap->dm_nsegs);
    409 	KASSERT(npages <= rdev->gart.num_cpu_pages);
    410 	KASSERT(gpu_npages <= rdev->gart.num_cpu_pages);
    411 
    412 	if (!rdev->gart.ready) {
    413 		WARN(1, "trying to bind memory to uninitialized GART !\n");
    414 		return -EINVAL;
    415 	}
    416 
    417 	radeon_gart_pre_update(rdev, gpu_pgstart, gpu_npages);
    418 	for (pgno = 0; pgno < npages; pgno++) {
    419 		const bus_addr_t addr = dmamap->dm_segs[pgno].ds_addr;
    420 
    421 		KASSERT(dmamap->dm_segs[pgno].ds_len == PAGE_SIZE);
    422 		rdev->gart.pages[pgstart + pgno] = pages[pgno];
    423 		for (gpu_pgno = 0; gpu_pgno < gpu_per_cpu; gpu_pgno++) {
    424 			const unsigned i = gpu_pgstart + gpu_per_cpu*pgno +
    425 			    gpu_pgno;
    426 			page_entry = radeon_gart_get_page_entry(
    427 				addr + gpu_pgno*RADEON_GPU_PAGE_SIZE, flags);
    428 			rdev->gart.pages_entry[i] = page_entry;
    429 			if (rdev->gart.ptr == NULL)
    430 				continue;
    431 			radeon_gart_set_page(rdev, i, page_entry);
    432 		}
    433 	}
    434 	radeon_gart_post_update(rdev, gpu_pgstart, gpu_npages);
    435 
    436 	return 0;
    437 }
    438 #else
    439 /**
    440  * radeon_gart_bind - bind pages into the gart page table
    441  *
    442  * @rdev: radeon_device pointer
    443  * @offset: offset into the GPU's gart aperture
    444  * @pages: number of pages to bind
    445  * @pagelist: pages to bind
    446  * @dma_addr: DMA addresses of pages
    447  * @flags: RADEON_GART_PAGE_* flags
    448  *
    449  * Binds the requested pages to the gart page table
    450  * (all asics).
    451  * Returns 0 for success, -EINVAL for failure.
    452  */
    453 int radeon_gart_bind(struct radeon_device *rdev, unsigned offset,
    454 		     int pages, struct page **pagelist, dma_addr_t *dma_addr,
    455 		     uint32_t flags)
    456 {
    457 	unsigned t;
    458 	unsigned p;
    459 	uint64_t page_base, page_entry;
    460 	int i, j;
    461 
    462 	if (!rdev->gart.ready) {
    463 		WARN(1, "trying to bind memory to uninitialized GART !\n");
    464 		return -EINVAL;
    465 	}
    466 	t = offset / RADEON_GPU_PAGE_SIZE;
    467 	p = t / (PAGE_SIZE / RADEON_GPU_PAGE_SIZE);
    468 
    469 	for (i = 0; i < pages; i++, p++) {
    470 		rdev->gart.pages[p] = pagelist[i];
    471 		page_base = dma_addr[i];
    472 		for (j = 0; j < (PAGE_SIZE / RADEON_GPU_PAGE_SIZE); j++, t++) {
    473 			page_entry = radeon_gart_get_page_entry(page_base, flags);
    474 			rdev->gart.pages_entry[t] = page_entry;
    475 			if (rdev->gart.ptr) {
    476 				radeon_gart_set_page(rdev, t, page_entry);
    477 			}
    478 			page_base += RADEON_GPU_PAGE_SIZE;
    479 		}
    480 	}
    481 	if (rdev->gart.ptr) {
    482 		mb();
    483 		radeon_gart_tlb_flush(rdev);
    484 	}
    485 	return 0;
    486 }
    487 #endif
    488 
    489 /**
    490  * radeon_gart_init - init the driver info for managing the gart
    491  *
    492  * @rdev: radeon_device pointer
    493  *
    494  * Allocate the dummy page and init the gart driver info (all asics).
    495  * Returns 0 for success, error for failure.
    496  */
    497 int radeon_gart_init(struct radeon_device *rdev)
    498 {
    499 	int r, i;
    500 
    501 	if (rdev->gart.pages) {
    502 		return 0;
    503 	}
    504 	/* We need PAGE_SIZE >= RADEON_GPU_PAGE_SIZE */
    505 	if (PAGE_SIZE < RADEON_GPU_PAGE_SIZE) {
    506 		DRM_ERROR("Page size is smaller than GPU page size!\n");
    507 		return -EINVAL;
    508 	}
    509 	r = radeon_dummy_page_init(rdev);
    510 	if (r)
    511 		return r;
    512 	/* Compute table size */
    513 	rdev->gart.num_cpu_pages = rdev->mc.gtt_size / PAGE_SIZE;
    514 	rdev->gart.num_gpu_pages = rdev->mc.gtt_size / RADEON_GPU_PAGE_SIZE;
    515 	DRM_INFO("GART: num cpu pages %u, num gpu pages %u\n",
    516 		 rdev->gart.num_cpu_pages, rdev->gart.num_gpu_pages);
    517 	/* Allocate pages table */
    518 	rdev->gart.pages = vzalloc(sizeof(void *) * rdev->gart.num_cpu_pages);
    519 	if (rdev->gart.pages == NULL) {
    520 		radeon_gart_fini(rdev);
    521 		return -ENOMEM;
    522 	}
    523 	rdev->gart.pages_entry = vmalloc(sizeof(uint64_t) *
    524 					 rdev->gart.num_gpu_pages);
    525 	if (rdev->gart.pages_entry == NULL) {
    526 		radeon_gart_fini(rdev);
    527 		return -ENOMEM;
    528 	}
    529 	/* set GART entry to point to the dummy page by default */
    530 	for (i = 0; i < rdev->gart.num_gpu_pages; i++)
    531 		rdev->gart.pages_entry[i] = rdev->dummy_page.entry;
    532 	return 0;
    533 }
    534 
    535 /**
    536  * radeon_gart_fini - tear down the driver info for managing the gart
    537  *
    538  * @rdev: radeon_device pointer
    539  *
    540  * Tear down the gart driver info and free the dummy page (all asics).
    541  */
    542 void radeon_gart_fini(struct radeon_device *rdev)
    543 {
    544 	if (rdev->gart.ready) {
    545 		/* unbind pages */
    546 		radeon_gart_unbind(rdev, 0, rdev->gart.num_cpu_pages);
    547 	}
    548 	rdev->gart.ready = false;
    549 	vfree(rdev->gart.pages);
    550 	vfree(rdev->gart.pages_entry);
    551 	rdev->gart.pages = NULL;
    552 	rdev->gart.pages_entry = NULL;
    553 
    554 	radeon_dummy_page_fini(rdev);
    555 }
    556