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vmwgfx_mob.c revision 1.1.1.2
      1 /*	$NetBSD: vmwgfx_mob.c,v 1.1.1.2 2018/08/27 01:35:00 riastradh Exp $	*/
      2 
      3 /**************************************************************************
      4  *
      5  * Copyright  2012-2015 VMware, Inc., Palo Alto, CA., USA
      6  * All Rights Reserved.
      7  *
      8  * Permission is hereby granted, free of charge, to any person obtaining a
      9  * copy of this software and associated documentation files (the
     10  * "Software"), to deal in the Software without restriction, including
     11  * without limitation the rights to use, copy, modify, merge, publish,
     12  * distribute, sub license, and/or sell copies of the Software, and to
     13  * permit persons to whom the Software is furnished to do so, subject to
     14  * the following conditions:
     15  *
     16  * The above copyright notice and this permission notice (including the
     17  * next paragraph) shall be included in all copies or substantial portions
     18  * of the Software.
     19  *
     20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     22  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
     23  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
     24  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
     25  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
     26  * USE OR OTHER DEALINGS IN THE SOFTWARE.
     27  *
     28  **************************************************************************/
     29 
     30 #include <sys/cdefs.h>
     31 __KERNEL_RCSID(0, "$NetBSD: vmwgfx_mob.c,v 1.1.1.2 2018/08/27 01:35:00 riastradh Exp $");
     32 
     33 #include "vmwgfx_drv.h"
     34 
     35 /*
     36  * If we set up the screen target otable, screen objects stop working.
     37  */
     38 
     39 #define VMW_OTABLE_SETUP_SUB ((VMWGFX_ENABLE_SCREEN_TARGET_OTABLE ? 0 : 1))
     40 
     41 #ifdef CONFIG_64BIT
     42 #define VMW_PPN_SIZE 8
     43 #define VMW_MOBFMT_PTDEPTH_0 SVGA3D_MOBFMT_PTDEPTH64_0
     44 #define VMW_MOBFMT_PTDEPTH_1 SVGA3D_MOBFMT_PTDEPTH64_1
     45 #define VMW_MOBFMT_PTDEPTH_2 SVGA3D_MOBFMT_PTDEPTH64_2
     46 #else
     47 #define VMW_PPN_SIZE 4
     48 #define VMW_MOBFMT_PTDEPTH_0 SVGA3D_MOBFMT_PTDEPTH_0
     49 #define VMW_MOBFMT_PTDEPTH_1 SVGA3D_MOBFMT_PTDEPTH_1
     50 #define VMW_MOBFMT_PTDEPTH_2 SVGA3D_MOBFMT_PTDEPTH_2
     51 #endif
     52 
     53 /*
     54  * struct vmw_mob - Structure containing page table and metadata for a
     55  * Guest Memory OBject.
     56  *
     57  * @num_pages       Number of pages that make up the page table.
     58  * @pt_level        The indirection level of the page table. 0-2.
     59  * @pt_root_page    DMA address of the level 0 page of the page table.
     60  */
     61 struct vmw_mob {
     62 	struct ttm_buffer_object *pt_bo;
     63 	unsigned long num_pages;
     64 	unsigned pt_level;
     65 	dma_addr_t pt_root_page;
     66 	uint32_t id;
     67 };
     68 
     69 /*
     70  * struct vmw_otable - Guest Memory OBject table metadata
     71  *
     72  * @size:           Size of the table (page-aligned).
     73  * @page_table:     Pointer to a struct vmw_mob holding the page table.
     74  */
     75 static const struct vmw_otable pre_dx_tables[] = {
     76 	{VMWGFX_NUM_MOB * SVGA3D_OTABLE_MOB_ENTRY_SIZE, NULL, true},
     77 	{VMWGFX_NUM_GB_SURFACE * SVGA3D_OTABLE_SURFACE_ENTRY_SIZE, NULL, true},
     78 	{VMWGFX_NUM_GB_CONTEXT * SVGA3D_OTABLE_CONTEXT_ENTRY_SIZE, NULL, true},
     79 	{VMWGFX_NUM_GB_SHADER * SVGA3D_OTABLE_SHADER_ENTRY_SIZE, NULL, true},
     80 	{VMWGFX_NUM_GB_SCREEN_TARGET * SVGA3D_OTABLE_SCREEN_TARGET_ENTRY_SIZE,
     81 	 NULL, VMWGFX_ENABLE_SCREEN_TARGET_OTABLE}
     82 };
     83 
     84 static const struct vmw_otable dx_tables[] = {
     85 	{VMWGFX_NUM_MOB * SVGA3D_OTABLE_MOB_ENTRY_SIZE, NULL, true},
     86 	{VMWGFX_NUM_GB_SURFACE * SVGA3D_OTABLE_SURFACE_ENTRY_SIZE, NULL, true},
     87 	{VMWGFX_NUM_GB_CONTEXT * SVGA3D_OTABLE_CONTEXT_ENTRY_SIZE, NULL, true},
     88 	{VMWGFX_NUM_GB_SHADER * SVGA3D_OTABLE_SHADER_ENTRY_SIZE, NULL, true},
     89 	{VMWGFX_NUM_GB_SCREEN_TARGET * SVGA3D_OTABLE_SCREEN_TARGET_ENTRY_SIZE,
     90 	 NULL, VMWGFX_ENABLE_SCREEN_TARGET_OTABLE},
     91 	{VMWGFX_NUM_DXCONTEXT * sizeof(SVGAOTableDXContextEntry), NULL, true},
     92 };
     93 
     94 static int vmw_mob_pt_populate(struct vmw_private *dev_priv,
     95 			       struct vmw_mob *mob);
     96 static void vmw_mob_pt_setup(struct vmw_mob *mob,
     97 			     struct vmw_piter data_iter,
     98 			     unsigned long num_data_pages);
     99 
    100 /*
    101  * vmw_setup_otable_base - Issue an object table base setup command to
    102  * the device
    103  *
    104  * @dev_priv:       Pointer to a device private structure
    105  * @type:           Type of object table base
    106  * @offset          Start of table offset into dev_priv::otable_bo
    107  * @otable          Pointer to otable metadata;
    108  *
    109  * This function returns -ENOMEM if it fails to reserve fifo space,
    110  * and may block waiting for fifo space.
    111  */
    112 static int vmw_setup_otable_base(struct vmw_private *dev_priv,
    113 				 SVGAOTableType type,
    114 				 struct ttm_buffer_object *otable_bo,
    115 				 unsigned long offset,
    116 				 struct vmw_otable *otable)
    117 {
    118 	struct {
    119 		SVGA3dCmdHeader header;
    120 		SVGA3dCmdSetOTableBase64 body;
    121 	} *cmd;
    122 	struct vmw_mob *mob;
    123 	const struct vmw_sg_table *vsgt;
    124 	struct vmw_piter iter;
    125 	int ret;
    126 
    127 	BUG_ON(otable->page_table != NULL);
    128 
    129 	vsgt = vmw_bo_sg_table(otable_bo);
    130 	vmw_piter_start(&iter, vsgt, offset >> PAGE_SHIFT);
    131 	WARN_ON(!vmw_piter_next(&iter));
    132 
    133 	mob = vmw_mob_create(otable->size >> PAGE_SHIFT);
    134 	if (unlikely(mob == NULL)) {
    135 		DRM_ERROR("Failed creating OTable page table.\n");
    136 		return -ENOMEM;
    137 	}
    138 
    139 	if (otable->size <= PAGE_SIZE) {
    140 		mob->pt_level = VMW_MOBFMT_PTDEPTH_0;
    141 		mob->pt_root_page = vmw_piter_dma_addr(&iter);
    142 	} else if (vsgt->num_regions == 1) {
    143 		mob->pt_level = SVGA3D_MOBFMT_RANGE;
    144 		mob->pt_root_page = vmw_piter_dma_addr(&iter);
    145 	} else {
    146 		ret = vmw_mob_pt_populate(dev_priv, mob);
    147 		if (unlikely(ret != 0))
    148 			goto out_no_populate;
    149 
    150 		vmw_mob_pt_setup(mob, iter, otable->size >> PAGE_SHIFT);
    151 		mob->pt_level += VMW_MOBFMT_PTDEPTH_1 - SVGA3D_MOBFMT_PTDEPTH_1;
    152 	}
    153 
    154 	cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));
    155 	if (unlikely(cmd == NULL)) {
    156 		DRM_ERROR("Failed reserving FIFO space for OTable setup.\n");
    157 		ret = -ENOMEM;
    158 		goto out_no_fifo;
    159 	}
    160 
    161 	memset(cmd, 0, sizeof(*cmd));
    162 	cmd->header.id = SVGA_3D_CMD_SET_OTABLE_BASE64;
    163 	cmd->header.size = sizeof(cmd->body);
    164 	cmd->body.type = type;
    165 	cmd->body.baseAddress = mob->pt_root_page >> PAGE_SHIFT;
    166 	cmd->body.sizeInBytes = otable->size;
    167 	cmd->body.validSizeInBytes = 0;
    168 	cmd->body.ptDepth = mob->pt_level;
    169 
    170 	/*
    171 	 * The device doesn't support this, But the otable size is
    172 	 * determined at compile-time, so this BUG shouldn't trigger
    173 	 * randomly.
    174 	 */
    175 	BUG_ON(mob->pt_level == VMW_MOBFMT_PTDEPTH_2);
    176 
    177 	vmw_fifo_commit(dev_priv, sizeof(*cmd));
    178 	otable->page_table = mob;
    179 
    180 	return 0;
    181 
    182 out_no_fifo:
    183 out_no_populate:
    184 	vmw_mob_destroy(mob);
    185 	return ret;
    186 }
    187 
    188 /*
    189  * vmw_takedown_otable_base - Issue an object table base takedown command
    190  * to the device
    191  *
    192  * @dev_priv:       Pointer to a device private structure
    193  * @type:           Type of object table base
    194  *
    195  */
    196 static void vmw_takedown_otable_base(struct vmw_private *dev_priv,
    197 				     SVGAOTableType type,
    198 				     struct vmw_otable *otable)
    199 {
    200 	struct {
    201 		SVGA3dCmdHeader header;
    202 		SVGA3dCmdSetOTableBase body;
    203 	} *cmd;
    204 	struct ttm_buffer_object *bo;
    205 
    206 	if (otable->page_table == NULL)
    207 		return;
    208 
    209 	bo = otable->page_table->pt_bo;
    210 	cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));
    211 	if (unlikely(cmd == NULL)) {
    212 		DRM_ERROR("Failed reserving FIFO space for OTable "
    213 			  "takedown.\n");
    214 		return;
    215 	}
    216 
    217 	memset(cmd, 0, sizeof(*cmd));
    218 	cmd->header.id = SVGA_3D_CMD_SET_OTABLE_BASE;
    219 	cmd->header.size = sizeof(cmd->body);
    220 	cmd->body.type = type;
    221 	cmd->body.baseAddress = 0;
    222 	cmd->body.sizeInBytes = 0;
    223 	cmd->body.validSizeInBytes = 0;
    224 	cmd->body.ptDepth = SVGA3D_MOBFMT_INVALID;
    225 	vmw_fifo_commit(dev_priv, sizeof(*cmd));
    226 
    227 	if (bo) {
    228 		int ret;
    229 
    230 		ret = ttm_bo_reserve(bo, false, true, false, NULL);
    231 		BUG_ON(ret != 0);
    232 
    233 		vmw_fence_single_bo(bo, NULL);
    234 		ttm_bo_unreserve(bo);
    235 	}
    236 
    237 	vmw_mob_destroy(otable->page_table);
    238 	otable->page_table = NULL;
    239 }
    240 
    241 
    242 static int vmw_otable_batch_setup(struct vmw_private *dev_priv,
    243 				  struct vmw_otable_batch *batch)
    244 {
    245 	unsigned long offset;
    246 	unsigned long bo_size;
    247 	struct vmw_otable *otables = batch->otables;
    248 	SVGAOTableType i;
    249 	int ret;
    250 
    251 	bo_size = 0;
    252 	for (i = 0; i < batch->num_otables; ++i) {
    253 		if (!otables[i].enabled)
    254 			continue;
    255 
    256 		otables[i].size =
    257 			(otables[i].size + PAGE_SIZE - 1) & PAGE_MASK;
    258 		bo_size += otables[i].size;
    259 	}
    260 
    261 	ret = ttm_bo_create(&dev_priv->bdev, bo_size,
    262 			    ttm_bo_type_device,
    263 			    &vmw_sys_ne_placement,
    264 			    0, false, NULL,
    265 			    &batch->otable_bo);
    266 
    267 	if (unlikely(ret != 0))
    268 		goto out_no_bo;
    269 
    270 	ret = ttm_bo_reserve(batch->otable_bo, false, true, false, NULL);
    271 	BUG_ON(ret != 0);
    272 	ret = vmw_bo_driver.ttm_tt_populate(batch->otable_bo->ttm);
    273 	if (unlikely(ret != 0))
    274 		goto out_unreserve;
    275 	ret = vmw_bo_map_dma(batch->otable_bo);
    276 	if (unlikely(ret != 0))
    277 		goto out_unreserve;
    278 
    279 	ttm_bo_unreserve(batch->otable_bo);
    280 
    281 	offset = 0;
    282 	for (i = 0; i < batch->num_otables; ++i) {
    283 		if (!batch->otables[i].enabled)
    284 			continue;
    285 
    286 		ret = vmw_setup_otable_base(dev_priv, i, batch->otable_bo,
    287 					    offset,
    288 					    &otables[i]);
    289 		if (unlikely(ret != 0))
    290 			goto out_no_setup;
    291 		offset += otables[i].size;
    292 	}
    293 
    294 	return 0;
    295 
    296 out_unreserve:
    297 	ttm_bo_unreserve(batch->otable_bo);
    298 out_no_setup:
    299 	for (i = 0; i < batch->num_otables; ++i) {
    300 		if (batch->otables[i].enabled)
    301 			vmw_takedown_otable_base(dev_priv, i,
    302 						 &batch->otables[i]);
    303 	}
    304 
    305 	ttm_bo_unref(&batch->otable_bo);
    306 out_no_bo:
    307 	return ret;
    308 }
    309 
    310 /*
    311  * vmw_otables_setup - Set up guest backed memory object tables
    312  *
    313  * @dev_priv:       Pointer to a device private structure
    314  *
    315  * Takes care of the device guest backed surface
    316  * initialization, by setting up the guest backed memory object tables.
    317  * Returns 0 on success and various error codes on failure. A successful return
    318  * means the object tables can be taken down using the vmw_otables_takedown
    319  * function.
    320  */
    321 int vmw_otables_setup(struct vmw_private *dev_priv)
    322 {
    323 	struct vmw_otable **otables = &dev_priv->otable_batch.otables;
    324 	int ret;
    325 
    326 	if (dev_priv->has_dx) {
    327 		*otables = kmalloc(sizeof(dx_tables), GFP_KERNEL);
    328 		if (*otables == NULL)
    329 			return -ENOMEM;
    330 
    331 		memcpy(*otables, dx_tables, sizeof(dx_tables));
    332 		dev_priv->otable_batch.num_otables = ARRAY_SIZE(dx_tables);
    333 	} else {
    334 		*otables = kmalloc(sizeof(pre_dx_tables), GFP_KERNEL);
    335 		if (*otables == NULL)
    336 			return -ENOMEM;
    337 
    338 		memcpy(*otables, pre_dx_tables, sizeof(pre_dx_tables));
    339 		dev_priv->otable_batch.num_otables = ARRAY_SIZE(pre_dx_tables);
    340 	}
    341 
    342 	ret = vmw_otable_batch_setup(dev_priv, &dev_priv->otable_batch);
    343 	if (unlikely(ret != 0))
    344 		goto out_setup;
    345 
    346 	return 0;
    347 
    348 out_setup:
    349 	kfree(*otables);
    350 	return ret;
    351 }
    352 
    353 static void vmw_otable_batch_takedown(struct vmw_private *dev_priv,
    354 			       struct vmw_otable_batch *batch)
    355 {
    356 	SVGAOTableType i;
    357 	struct ttm_buffer_object *bo = batch->otable_bo;
    358 	int ret;
    359 
    360 	for (i = 0; i < batch->num_otables; ++i)
    361 		if (batch->otables[i].enabled)
    362 			vmw_takedown_otable_base(dev_priv, i,
    363 						 &batch->otables[i]);
    364 
    365 	ret = ttm_bo_reserve(bo, false, true, false, NULL);
    366 	BUG_ON(ret != 0);
    367 
    368 	vmw_fence_single_bo(bo, NULL);
    369 	ttm_bo_unreserve(bo);
    370 
    371 	ttm_bo_unref(&batch->otable_bo);
    372 }
    373 
    374 /*
    375  * vmw_otables_takedown - Take down guest backed memory object tables
    376  *
    377  * @dev_priv:       Pointer to a device private structure
    378  *
    379  * Take down the Guest Memory Object tables.
    380  */
    381 void vmw_otables_takedown(struct vmw_private *dev_priv)
    382 {
    383 	vmw_otable_batch_takedown(dev_priv, &dev_priv->otable_batch);
    384 	kfree(dev_priv->otable_batch.otables);
    385 }
    386 
    387 /*
    388  * vmw_mob_calculate_pt_pages - Calculate the number of page table pages
    389  * needed for a guest backed memory object.
    390  *
    391  * @data_pages:  Number of data pages in the memory object buffer.
    392  */
    393 static unsigned long vmw_mob_calculate_pt_pages(unsigned long data_pages)
    394 {
    395 	unsigned long data_size = data_pages * PAGE_SIZE;
    396 	unsigned long tot_size = 0;
    397 
    398 	while (likely(data_size > PAGE_SIZE)) {
    399 		data_size = DIV_ROUND_UP(data_size, PAGE_SIZE);
    400 		data_size *= VMW_PPN_SIZE;
    401 		tot_size += (data_size + PAGE_SIZE - 1) & PAGE_MASK;
    402 	}
    403 
    404 	return tot_size >> PAGE_SHIFT;
    405 }
    406 
    407 /*
    408  * vmw_mob_create - Create a mob, but don't populate it.
    409  *
    410  * @data_pages:  Number of data pages of the underlying buffer object.
    411  */
    412 struct vmw_mob *vmw_mob_create(unsigned long data_pages)
    413 {
    414 	struct vmw_mob *mob = kzalloc(sizeof(*mob), GFP_KERNEL);
    415 
    416 	if (unlikely(mob == NULL))
    417 		return NULL;
    418 
    419 	mob->num_pages = vmw_mob_calculate_pt_pages(data_pages);
    420 
    421 	return mob;
    422 }
    423 
    424 /*
    425  * vmw_mob_pt_populate - Populate the mob pagetable
    426  *
    427  * @mob:         Pointer to the mob the pagetable of which we want to
    428  *               populate.
    429  *
    430  * This function allocates memory to be used for the pagetable, and
    431  * adjusts TTM memory accounting accordingly. Returns ENOMEM if
    432  * memory resources aren't sufficient and may cause TTM buffer objects
    433  * to be swapped out by using the TTM memory accounting function.
    434  */
    435 static int vmw_mob_pt_populate(struct vmw_private *dev_priv,
    436 			       struct vmw_mob *mob)
    437 {
    438 	int ret;
    439 	BUG_ON(mob->pt_bo != NULL);
    440 
    441 	ret = ttm_bo_create(&dev_priv->bdev, mob->num_pages * PAGE_SIZE,
    442 			    ttm_bo_type_device,
    443 			    &vmw_sys_ne_placement,
    444 			    0, false, NULL, &mob->pt_bo);
    445 	if (unlikely(ret != 0))
    446 		return ret;
    447 
    448 	ret = ttm_bo_reserve(mob->pt_bo, false, true, false, NULL);
    449 
    450 	BUG_ON(ret != 0);
    451 	ret = vmw_bo_driver.ttm_tt_populate(mob->pt_bo->ttm);
    452 	if (unlikely(ret != 0))
    453 		goto out_unreserve;
    454 	ret = vmw_bo_map_dma(mob->pt_bo);
    455 	if (unlikely(ret != 0))
    456 		goto out_unreserve;
    457 
    458 	ttm_bo_unreserve(mob->pt_bo);
    459 
    460 	return 0;
    461 
    462 out_unreserve:
    463 	ttm_bo_unreserve(mob->pt_bo);
    464 	ttm_bo_unref(&mob->pt_bo);
    465 
    466 	return ret;
    467 }
    468 
    469 /**
    470  * vmw_mob_assign_ppn - Assign a value to a page table entry
    471  *
    472  * @addr: Pointer to pointer to page table entry.
    473  * @val: The page table entry
    474  *
    475  * Assigns a value to a page table entry pointed to by *@addr and increments
    476  * *@addr according to the page table entry size.
    477  */
    478 #if (VMW_PPN_SIZE == 8)
    479 static void vmw_mob_assign_ppn(u32 **addr, dma_addr_t val)
    480 {
    481 	*((u64 *) *addr) = val >> PAGE_SHIFT;
    482 	*addr += 2;
    483 }
    484 #else
    485 static void vmw_mob_assign_ppn(u32 **addr, dma_addr_t val)
    486 {
    487 	*(*addr)++ = val >> PAGE_SHIFT;
    488 }
    489 #endif
    490 
    491 /*
    492  * vmw_mob_build_pt - Build a pagetable
    493  *
    494  * @data_addr:      Array of DMA addresses to the underlying buffer
    495  *                  object's data pages.
    496  * @num_data_pages: Number of buffer object data pages.
    497  * @pt_pages:       Array of page pointers to the page table pages.
    498  *
    499  * Returns the number of page table pages actually used.
    500  * Uses atomic kmaps of highmem pages to avoid TLB thrashing.
    501  */
    502 static unsigned long vmw_mob_build_pt(struct vmw_piter *data_iter,
    503 				      unsigned long num_data_pages,
    504 				      struct vmw_piter *pt_iter)
    505 {
    506 	unsigned long pt_size = num_data_pages * VMW_PPN_SIZE;
    507 	unsigned long num_pt_pages = DIV_ROUND_UP(pt_size, PAGE_SIZE);
    508 	unsigned long pt_page;
    509 	u32 *addr, *save_addr;
    510 	unsigned long i;
    511 	struct page *page;
    512 
    513 	for (pt_page = 0; pt_page < num_pt_pages; ++pt_page) {
    514 		page = vmw_piter_page(pt_iter);
    515 
    516 		save_addr = addr = kmap_atomic(page);
    517 
    518 		for (i = 0; i < PAGE_SIZE / VMW_PPN_SIZE; ++i) {
    519 			vmw_mob_assign_ppn(&addr,
    520 					   vmw_piter_dma_addr(data_iter));
    521 			if (unlikely(--num_data_pages == 0))
    522 				break;
    523 			WARN_ON(!vmw_piter_next(data_iter));
    524 		}
    525 		kunmap_atomic(save_addr);
    526 		vmw_piter_next(pt_iter);
    527 	}
    528 
    529 	return num_pt_pages;
    530 }
    531 
    532 /*
    533  * vmw_mob_build_pt - Set up a multilevel mob pagetable
    534  *
    535  * @mob:            Pointer to a mob whose page table needs setting up.
    536  * @data_addr       Array of DMA addresses to the buffer object's data
    537  *                  pages.
    538  * @num_data_pages: Number of buffer object data pages.
    539  *
    540  * Uses tail recursion to set up a multilevel mob page table.
    541  */
    542 static void vmw_mob_pt_setup(struct vmw_mob *mob,
    543 			     struct vmw_piter data_iter,
    544 			     unsigned long num_data_pages)
    545 {
    546 	unsigned long num_pt_pages = 0;
    547 	struct ttm_buffer_object *bo = mob->pt_bo;
    548 	struct vmw_piter save_pt_iter;
    549 	struct vmw_piter pt_iter;
    550 	const struct vmw_sg_table *vsgt;
    551 	int ret;
    552 
    553 	ret = ttm_bo_reserve(bo, false, true, false, NULL);
    554 	BUG_ON(ret != 0);
    555 
    556 	vsgt = vmw_bo_sg_table(bo);
    557 	vmw_piter_start(&pt_iter, vsgt, 0);
    558 	BUG_ON(!vmw_piter_next(&pt_iter));
    559 	mob->pt_level = 0;
    560 	while (likely(num_data_pages > 1)) {
    561 		++mob->pt_level;
    562 		BUG_ON(mob->pt_level > 2);
    563 		save_pt_iter = pt_iter;
    564 		num_pt_pages = vmw_mob_build_pt(&data_iter, num_data_pages,
    565 						&pt_iter);
    566 		data_iter = save_pt_iter;
    567 		num_data_pages = num_pt_pages;
    568 	}
    569 
    570 	mob->pt_root_page = vmw_piter_dma_addr(&save_pt_iter);
    571 	ttm_bo_unreserve(bo);
    572 }
    573 
    574 /*
    575  * vmw_mob_destroy - Destroy a mob, unpopulating first if necessary.
    576  *
    577  * @mob:            Pointer to a mob to destroy.
    578  */
    579 void vmw_mob_destroy(struct vmw_mob *mob)
    580 {
    581 	if (mob->pt_bo)
    582 		ttm_bo_unref(&mob->pt_bo);
    583 	kfree(mob);
    584 }
    585 
    586 /*
    587  * vmw_mob_unbind - Hide a mob from the device.
    588  *
    589  * @dev_priv:       Pointer to a device private.
    590  * @mob_id:         Device id of the mob to unbind.
    591  */
    592 void vmw_mob_unbind(struct vmw_private *dev_priv,
    593 		    struct vmw_mob *mob)
    594 {
    595 	struct {
    596 		SVGA3dCmdHeader header;
    597 		SVGA3dCmdDestroyGBMob body;
    598 	} *cmd;
    599 	int ret;
    600 	struct ttm_buffer_object *bo = mob->pt_bo;
    601 
    602 	if (bo) {
    603 		ret = ttm_bo_reserve(bo, false, true, false, NULL);
    604 		/*
    605 		 * Noone else should be using this buffer.
    606 		 */
    607 		BUG_ON(ret != 0);
    608 	}
    609 
    610 	cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));
    611 	if (unlikely(cmd == NULL)) {
    612 		DRM_ERROR("Failed reserving FIFO space for Memory "
    613 			  "Object unbinding.\n");
    614 	} else {
    615 		cmd->header.id = SVGA_3D_CMD_DESTROY_GB_MOB;
    616 		cmd->header.size = sizeof(cmd->body);
    617 		cmd->body.mobid = mob->id;
    618 		vmw_fifo_commit(dev_priv, sizeof(*cmd));
    619 	}
    620 	if (bo) {
    621 		vmw_fence_single_bo(bo, NULL);
    622 		ttm_bo_unreserve(bo);
    623 	}
    624 	vmw_fifo_resource_dec(dev_priv);
    625 }
    626 
    627 /*
    628  * vmw_mob_bind - Make a mob visible to the device after first
    629  *                populating it if necessary.
    630  *
    631  * @dev_priv:       Pointer to a device private.
    632  * @mob:            Pointer to the mob we're making visible.
    633  * @data_addr:      Array of DMA addresses to the data pages of the underlying
    634  *                  buffer object.
    635  * @num_data_pages: Number of data pages of the underlying buffer
    636  *                  object.
    637  * @mob_id:         Device id of the mob to bind
    638  *
    639  * This function is intended to be interfaced with the ttm_tt backend
    640  * code.
    641  */
    642 int vmw_mob_bind(struct vmw_private *dev_priv,
    643 		 struct vmw_mob *mob,
    644 		 const struct vmw_sg_table *vsgt,
    645 		 unsigned long num_data_pages,
    646 		 int32_t mob_id)
    647 {
    648 	int ret;
    649 	bool pt_set_up = false;
    650 	struct vmw_piter data_iter;
    651 	struct {
    652 		SVGA3dCmdHeader header;
    653 		SVGA3dCmdDefineGBMob64 body;
    654 	} *cmd;
    655 
    656 	mob->id = mob_id;
    657 	vmw_piter_start(&data_iter, vsgt, 0);
    658 	if (unlikely(!vmw_piter_next(&data_iter)))
    659 		return 0;
    660 
    661 	if (likely(num_data_pages == 1)) {
    662 		mob->pt_level = VMW_MOBFMT_PTDEPTH_0;
    663 		mob->pt_root_page = vmw_piter_dma_addr(&data_iter);
    664 	} else if (vsgt->num_regions == 1) {
    665 		mob->pt_level = SVGA3D_MOBFMT_RANGE;
    666 		mob->pt_root_page = vmw_piter_dma_addr(&data_iter);
    667 	} else if (unlikely(mob->pt_bo == NULL)) {
    668 		ret = vmw_mob_pt_populate(dev_priv, mob);
    669 		if (unlikely(ret != 0))
    670 			return ret;
    671 
    672 		vmw_mob_pt_setup(mob, data_iter, num_data_pages);
    673 		pt_set_up = true;
    674 		mob->pt_level += VMW_MOBFMT_PTDEPTH_1 - SVGA3D_MOBFMT_PTDEPTH_1;
    675 	}
    676 
    677 	vmw_fifo_resource_inc(dev_priv);
    678 
    679 	cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));
    680 	if (unlikely(cmd == NULL)) {
    681 		DRM_ERROR("Failed reserving FIFO space for Memory "
    682 			  "Object binding.\n");
    683 		goto out_no_cmd_space;
    684 	}
    685 
    686 	cmd->header.id = SVGA_3D_CMD_DEFINE_GB_MOB64;
    687 	cmd->header.size = sizeof(cmd->body);
    688 	cmd->body.mobid = mob_id;
    689 	cmd->body.ptDepth = mob->pt_level;
    690 	cmd->body.base = mob->pt_root_page >> PAGE_SHIFT;
    691 	cmd->body.sizeInBytes = num_data_pages * PAGE_SIZE;
    692 
    693 	vmw_fifo_commit(dev_priv, sizeof(*cmd));
    694 
    695 	return 0;
    696 
    697 out_no_cmd_space:
    698 	vmw_fifo_resource_dec(dev_priv);
    699 	if (pt_set_up)
    700 		ttm_bo_unref(&mob->pt_bo);
    701 
    702 	return -ENOMEM;
    703 }
    704