1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /**************************************************************************
3  *
4  * Copyright 2012-2015 VMware, Inc., Palo Alto, CA., USA
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sub license, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * 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 NON-INFRINGEMENT. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
26  **************************************************************************/
27 
28 #include <linux/highmem.h>
29 
30 #include "vmwgfx_drv.h"
31 
32 /*
33  * If we set up the screen target otable, screen objects stop working.
34  */
35 
36 #define VMW_OTABLE_SETUP_SUB ((VMWGFX_ENABLE_SCREEN_TARGET_OTABLE ? 0 : 1))
37 
38 #ifdef CONFIG_64BIT
39 #define VMW_PPN_SIZE 8
40 #define VMW_MOBFMT_PTDEPTH_0 SVGA3D_MOBFMT_PTDEPTH64_0
41 #define VMW_MOBFMT_PTDEPTH_1 SVGA3D_MOBFMT_PTDEPTH64_1
42 #define VMW_MOBFMT_PTDEPTH_2 SVGA3D_MOBFMT_PTDEPTH64_2
43 #else
44 #define VMW_PPN_SIZE 4
45 #define VMW_MOBFMT_PTDEPTH_0 SVGA3D_MOBFMT_PTDEPTH_0
46 #define VMW_MOBFMT_PTDEPTH_1 SVGA3D_MOBFMT_PTDEPTH_1
47 #define VMW_MOBFMT_PTDEPTH_2 SVGA3D_MOBFMT_PTDEPTH_2
48 #endif
49 
50 /*
51  * struct vmw_mob - Structure containing page table and metadata for a
52  * Guest Memory OBject.
53  *
54  * @num_pages       Number of pages that make up the page table.
55  * @pt_level        The indirection level of the page table. 0-2.
56  * @pt_root_page    DMA address of the level 0 page of the page table.
57  */
58 struct vmw_mob {
59 	struct ttm_buffer_object *pt_bo;
60 	unsigned long num_pages;
61 	unsigned pt_level;
62 	dma_addr_t pt_root_page;
63 	uint32_t id;
64 };
65 
66 /*
67  * struct vmw_otable - Guest Memory OBject table metadata
68  *
69  * @size:           Size of the table (page-aligned).
70  * @page_table:     Pointer to a struct vmw_mob holding the page table.
71  */
72 static const struct vmw_otable pre_dx_tables[] = {
73 	{VMWGFX_NUM_MOB * SVGA3D_OTABLE_MOB_ENTRY_SIZE, NULL, true},
74 	{VMWGFX_NUM_GB_SURFACE * SVGA3D_OTABLE_SURFACE_ENTRY_SIZE, NULL, true},
75 	{VMWGFX_NUM_GB_CONTEXT * SVGA3D_OTABLE_CONTEXT_ENTRY_SIZE, NULL, true},
76 	{VMWGFX_NUM_GB_SHADER * SVGA3D_OTABLE_SHADER_ENTRY_SIZE, NULL, true},
77 	{VMWGFX_NUM_GB_SCREEN_TARGET * SVGA3D_OTABLE_SCREEN_TARGET_ENTRY_SIZE,
78 	 NULL, VMWGFX_ENABLE_SCREEN_TARGET_OTABLE}
79 };
80 
81 static const struct vmw_otable dx_tables[] = {
82 	{VMWGFX_NUM_MOB * SVGA3D_OTABLE_MOB_ENTRY_SIZE, NULL, true},
83 	{VMWGFX_NUM_GB_SURFACE * SVGA3D_OTABLE_SURFACE_ENTRY_SIZE, NULL, true},
84 	{VMWGFX_NUM_GB_CONTEXT * SVGA3D_OTABLE_CONTEXT_ENTRY_SIZE, NULL, true},
85 	{VMWGFX_NUM_GB_SHADER * SVGA3D_OTABLE_SHADER_ENTRY_SIZE, NULL, true},
86 	{VMWGFX_NUM_GB_SCREEN_TARGET * SVGA3D_OTABLE_SCREEN_TARGET_ENTRY_SIZE,
87 	 NULL, VMWGFX_ENABLE_SCREEN_TARGET_OTABLE},
88 	{VMWGFX_NUM_DXCONTEXT * sizeof(SVGAOTableDXContextEntry), NULL, true},
89 };
90 
91 static int vmw_mob_pt_populate(struct vmw_private *dev_priv,
92 			       struct vmw_mob *mob);
93 static void vmw_mob_pt_setup(struct vmw_mob *mob,
94 			     struct vmw_piter data_iter,
95 			     unsigned long num_data_pages);
96 
97 /*
98  * vmw_setup_otable_base - Issue an object table base setup command to
99  * the device
100  *
101  * @dev_priv:       Pointer to a device private structure
102  * @type:           Type of object table base
103  * @offset          Start of table offset into dev_priv::otable_bo
104  * @otable          Pointer to otable metadata;
105  *
106  * This function returns -ENOMEM if it fails to reserve fifo space,
107  * and may block waiting for fifo space.
108  */
109 static int vmw_setup_otable_base(struct vmw_private *dev_priv,
110 				 SVGAOTableType type,
111 				 struct ttm_buffer_object *otable_bo,
112 				 unsigned long offset,
113 				 struct vmw_otable *otable)
114 {
115 	struct {
116 		SVGA3dCmdHeader header;
117 		SVGA3dCmdSetOTableBase64 body;
118 	} *cmd;
119 	struct vmw_mob *mob;
120 	const struct vmw_sg_table *vsgt;
121 	struct vmw_piter iter;
122 	int ret;
123 
124 	BUG_ON(otable->page_table != NULL);
125 
126 	vsgt = vmw_bo_sg_table(otable_bo);
127 	vmw_piter_start(&iter, vsgt, offset >> PAGE_SHIFT);
128 	WARN_ON(!vmw_piter_next(&iter));
129 
130 	mob = vmw_mob_create(otable->size >> PAGE_SHIFT);
131 	if (unlikely(mob == NULL)) {
132 		DRM_ERROR("Failed creating OTable page table.\n");
133 		return -ENOMEM;
134 	}
135 
136 	if (otable->size <= PAGE_SIZE) {
137 		mob->pt_level = VMW_MOBFMT_PTDEPTH_0;
138 		mob->pt_root_page = vmw_piter_dma_addr(&iter);
139 	} else if (vsgt->num_regions == 1) {
140 		mob->pt_level = SVGA3D_MOBFMT_RANGE;
141 		mob->pt_root_page = vmw_piter_dma_addr(&iter);
142 	} else {
143 		ret = vmw_mob_pt_populate(dev_priv, mob);
144 		if (unlikely(ret != 0))
145 			goto out_no_populate;
146 
147 		vmw_mob_pt_setup(mob, iter, otable->size >> PAGE_SHIFT);
148 		mob->pt_level += VMW_MOBFMT_PTDEPTH_1 - SVGA3D_MOBFMT_PTDEPTH_1;
149 	}
150 
151 	cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
152 	if (unlikely(cmd == NULL)) {
153 		ret = -ENOMEM;
154 		goto out_no_fifo;
155 	}
156 
157 	memset(cmd, 0, sizeof(*cmd));
158 	cmd->header.id = SVGA_3D_CMD_SET_OTABLE_BASE64;
159 	cmd->header.size = sizeof(cmd->body);
160 	cmd->body.type = type;
161 	cmd->body.baseAddress = mob->pt_root_page >> PAGE_SHIFT;
162 	cmd->body.sizeInBytes = otable->size;
163 	cmd->body.validSizeInBytes = 0;
164 	cmd->body.ptDepth = mob->pt_level;
165 
166 	/*
167 	 * The device doesn't support this, But the otable size is
168 	 * determined at compile-time, so this BUG shouldn't trigger
169 	 * randomly.
170 	 */
171 	BUG_ON(mob->pt_level == VMW_MOBFMT_PTDEPTH_2);
172 
173 	vmw_cmd_commit(dev_priv, sizeof(*cmd));
174 	otable->page_table = mob;
175 
176 	return 0;
177 
178 out_no_fifo:
179 out_no_populate:
180 	vmw_mob_destroy(mob);
181 	return ret;
182 }
183 
184 /*
185  * vmw_takedown_otable_base - Issue an object table base takedown command
186  * to the device
187  *
188  * @dev_priv:       Pointer to a device private structure
189  * @type:           Type of object table base
190  *
191  */
192 static void vmw_takedown_otable_base(struct vmw_private *dev_priv,
193 				     SVGAOTableType type,
194 				     struct vmw_otable *otable)
195 {
196 	struct {
197 		SVGA3dCmdHeader header;
198 		SVGA3dCmdSetOTableBase body;
199 	} *cmd;
200 	struct ttm_buffer_object *bo;
201 
202 	if (otable->page_table == NULL)
203 		return;
204 
205 	bo = otable->page_table->pt_bo;
206 	cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
207 	if (unlikely(cmd == NULL))
208 		return;
209 
210 	memset(cmd, 0, sizeof(*cmd));
211 	cmd->header.id = SVGA_3D_CMD_SET_OTABLE_BASE;
212 	cmd->header.size = sizeof(cmd->body);
213 	cmd->body.type = type;
214 	cmd->body.baseAddress = 0;
215 	cmd->body.sizeInBytes = 0;
216 	cmd->body.validSizeInBytes = 0;
217 	cmd->body.ptDepth = SVGA3D_MOBFMT_INVALID;
218 	vmw_cmd_commit(dev_priv, sizeof(*cmd));
219 
220 	if (bo) {
221 		int ret;
222 
223 		ret = ttm_bo_reserve(bo, false, true, NULL);
224 		BUG_ON(ret != 0);
225 
226 		vmw_bo_fence_single(bo, NULL);
227 		ttm_bo_unreserve(bo);
228 	}
229 
230 	vmw_mob_destroy(otable->page_table);
231 	otable->page_table = NULL;
232 }
233 
234 
235 static int vmw_otable_batch_setup(struct vmw_private *dev_priv,
236 				  struct vmw_otable_batch *batch)
237 {
238 	unsigned long offset;
239 	unsigned long bo_size;
240 	struct vmw_otable *otables = batch->otables;
241 	SVGAOTableType i;
242 	int ret;
243 
244 	bo_size = 0;
245 	for (i = 0; i < batch->num_otables; ++i) {
246 		if (!otables[i].enabled)
247 			continue;
248 
249 		otables[i].size =
250 			(otables[i].size + PAGE_SIZE - 1) & PAGE_MASK;
251 		bo_size += otables[i].size;
252 	}
253 
254 	ret = vmw_bo_create_and_populate(dev_priv, bo_size, &batch->otable_bo);
255 	if (unlikely(ret != 0))
256 		return ret;
257 
258 	offset = 0;
259 	for (i = 0; i < batch->num_otables; ++i) {
260 		if (!batch->otables[i].enabled)
261 			continue;
262 
263 		ret = vmw_setup_otable_base(dev_priv, i, batch->otable_bo,
264 					    offset,
265 					    &otables[i]);
266 		if (unlikely(ret != 0))
267 			goto out_no_setup;
268 		offset += otables[i].size;
269 	}
270 
271 	return 0;
272 
273 out_no_setup:
274 	for (i = 0; i < batch->num_otables; ++i) {
275 		if (batch->otables[i].enabled)
276 			vmw_takedown_otable_base(dev_priv, i,
277 						 &batch->otables[i]);
278 	}
279 
280 	ttm_bo_unpin(batch->otable_bo);
281 	ttm_bo_put(batch->otable_bo);
282 	batch->otable_bo = NULL;
283 	return ret;
284 }
285 
286 /*
287  * vmw_otables_setup - Set up guest backed memory object tables
288  *
289  * @dev_priv:       Pointer to a device private structure
290  *
291  * Takes care of the device guest backed surface
292  * initialization, by setting up the guest backed memory object tables.
293  * Returns 0 on success and various error codes on failure. A successful return
294  * means the object tables can be taken down using the vmw_otables_takedown
295  * function.
296  */
297 int vmw_otables_setup(struct vmw_private *dev_priv)
298 {
299 	struct vmw_otable **otables = &dev_priv->otable_batch.otables;
300 	int ret;
301 
302 	if (has_sm4_context(dev_priv)) {
303 		*otables = kmemdup(dx_tables, sizeof(dx_tables), GFP_KERNEL);
304 		if (!(*otables))
305 			return -ENOMEM;
306 
307 		dev_priv->otable_batch.num_otables = ARRAY_SIZE(dx_tables);
308 	} else {
309 		*otables = kmemdup(pre_dx_tables, sizeof(pre_dx_tables),
310 				   GFP_KERNEL);
311 		if (!(*otables))
312 			return -ENOMEM;
313 
314 		dev_priv->otable_batch.num_otables = ARRAY_SIZE(pre_dx_tables);
315 	}
316 
317 	ret = vmw_otable_batch_setup(dev_priv, &dev_priv->otable_batch);
318 	if (unlikely(ret != 0))
319 		goto out_setup;
320 
321 	return 0;
322 
323 out_setup:
324 	kfree(*otables);
325 	return ret;
326 }
327 
328 static void vmw_otable_batch_takedown(struct vmw_private *dev_priv,
329 			       struct vmw_otable_batch *batch)
330 {
331 	SVGAOTableType i;
332 	struct ttm_buffer_object *bo = batch->otable_bo;
333 	int ret;
334 
335 	for (i = 0; i < batch->num_otables; ++i)
336 		if (batch->otables[i].enabled)
337 			vmw_takedown_otable_base(dev_priv, i,
338 						 &batch->otables[i]);
339 
340 	ret = ttm_bo_reserve(bo, false, true, NULL);
341 	BUG_ON(ret != 0);
342 
343 	vmw_bo_fence_single(bo, NULL);
344 	ttm_bo_unreserve(bo);
345 
346 	ttm_bo_unpin(batch->otable_bo);
347 	ttm_bo_put(batch->otable_bo);
348 	batch->otable_bo = NULL;
349 }
350 
351 /*
352  * vmw_otables_takedown - Take down guest backed memory object tables
353  *
354  * @dev_priv:       Pointer to a device private structure
355  *
356  * Take down the Guest Memory Object tables.
357  */
358 void vmw_otables_takedown(struct vmw_private *dev_priv)
359 {
360 	vmw_otable_batch_takedown(dev_priv, &dev_priv->otable_batch);
361 	kfree(dev_priv->otable_batch.otables);
362 }
363 
364 /*
365  * vmw_mob_calculate_pt_pages - Calculate the number of page table pages
366  * needed for a guest backed memory object.
367  *
368  * @data_pages:  Number of data pages in the memory object buffer.
369  */
370 static unsigned long vmw_mob_calculate_pt_pages(unsigned long data_pages)
371 {
372 	unsigned long data_size = data_pages * PAGE_SIZE;
373 	unsigned long tot_size = 0;
374 
375 	while (likely(data_size > PAGE_SIZE)) {
376 		data_size = DIV_ROUND_UP(data_size, PAGE_SIZE);
377 		data_size *= VMW_PPN_SIZE;
378 		tot_size += (data_size + PAGE_SIZE - 1) & PAGE_MASK;
379 	}
380 
381 	return tot_size >> PAGE_SHIFT;
382 }
383 
384 /*
385  * vmw_mob_create - Create a mob, but don't populate it.
386  *
387  * @data_pages:  Number of data pages of the underlying buffer object.
388  */
389 struct vmw_mob *vmw_mob_create(unsigned long data_pages)
390 {
391 	struct vmw_mob *mob = kzalloc(sizeof(*mob), GFP_KERNEL);
392 
393 	if (unlikely(!mob))
394 		return NULL;
395 
396 	mob->num_pages = vmw_mob_calculate_pt_pages(data_pages);
397 
398 	return mob;
399 }
400 
401 /*
402  * vmw_mob_pt_populate - Populate the mob pagetable
403  *
404  * @mob:         Pointer to the mob the pagetable of which we want to
405  *               populate.
406  *
407  * This function allocates memory to be used for the pagetable, and
408  * adjusts TTM memory accounting accordingly. Returns ENOMEM if
409  * memory resources aren't sufficient and may cause TTM buffer objects
410  * to be swapped out by using the TTM memory accounting function.
411  */
412 static int vmw_mob_pt_populate(struct vmw_private *dev_priv,
413 			       struct vmw_mob *mob)
414 {
415 	BUG_ON(mob->pt_bo != NULL);
416 
417 	return vmw_bo_create_and_populate(dev_priv, mob->num_pages * PAGE_SIZE, &mob->pt_bo);
418 }
419 
420 /**
421  * vmw_mob_assign_ppn - Assign a value to a page table entry
422  *
423  * @addr: Pointer to pointer to page table entry.
424  * @val: The page table entry
425  *
426  * Assigns a value to a page table entry pointed to by *@addr and increments
427  * *@addr according to the page table entry size.
428  */
429 #if (VMW_PPN_SIZE == 8)
430 static void vmw_mob_assign_ppn(u32 **addr, dma_addr_t val)
431 {
432 	*((u64 *) *addr) = val >> PAGE_SHIFT;
433 	*addr += 2;
434 }
435 #else
436 static void vmw_mob_assign_ppn(u32 **addr, dma_addr_t val)
437 {
438 	*(*addr)++ = val >> PAGE_SHIFT;
439 }
440 #endif
441 
442 /*
443  * vmw_mob_build_pt - Build a pagetable
444  *
445  * @data_addr:      Array of DMA addresses to the underlying buffer
446  *                  object's data pages.
447  * @num_data_pages: Number of buffer object data pages.
448  * @pt_pages:       Array of page pointers to the page table pages.
449  *
450  * Returns the number of page table pages actually used.
451  * Uses atomic kmaps of highmem pages to avoid TLB thrashing.
452  */
453 static unsigned long vmw_mob_build_pt(struct vmw_piter *data_iter,
454 				      unsigned long num_data_pages,
455 				      struct vmw_piter *pt_iter)
456 {
457 	unsigned long pt_size = num_data_pages * VMW_PPN_SIZE;
458 	unsigned long num_pt_pages = DIV_ROUND_UP(pt_size, PAGE_SIZE);
459 	unsigned long pt_page;
460 	u32 *addr, *save_addr;
461 	unsigned long i;
462 	struct page *page;
463 
464 	for (pt_page = 0; pt_page < num_pt_pages; ++pt_page) {
465 		page = vmw_piter_page(pt_iter);
466 
467 		save_addr = addr = kmap_atomic(page);
468 
469 		for (i = 0; i < PAGE_SIZE / VMW_PPN_SIZE; ++i) {
470 			vmw_mob_assign_ppn(&addr,
471 					   vmw_piter_dma_addr(data_iter));
472 			if (unlikely(--num_data_pages == 0))
473 				break;
474 			WARN_ON(!vmw_piter_next(data_iter));
475 		}
476 		kunmap_atomic(save_addr);
477 		vmw_piter_next(pt_iter);
478 	}
479 
480 	return num_pt_pages;
481 }
482 
483 /*
484  * vmw_mob_build_pt - Set up a multilevel mob pagetable
485  *
486  * @mob:            Pointer to a mob whose page table needs setting up.
487  * @data_addr       Array of DMA addresses to the buffer object's data
488  *                  pages.
489  * @num_data_pages: Number of buffer object data pages.
490  *
491  * Uses tail recursion to set up a multilevel mob page table.
492  */
493 static void vmw_mob_pt_setup(struct vmw_mob *mob,
494 			     struct vmw_piter data_iter,
495 			     unsigned long num_data_pages)
496 {
497 	unsigned long num_pt_pages = 0;
498 	struct ttm_buffer_object *bo = mob->pt_bo;
499 	struct vmw_piter save_pt_iter;
500 	struct vmw_piter pt_iter;
501 	const struct vmw_sg_table *vsgt;
502 	int ret;
503 
504 	ret = ttm_bo_reserve(bo, false, true, NULL);
505 	BUG_ON(ret != 0);
506 
507 	vsgt = vmw_bo_sg_table(bo);
508 	vmw_piter_start(&pt_iter, vsgt, 0);
509 	BUG_ON(!vmw_piter_next(&pt_iter));
510 	mob->pt_level = 0;
511 	while (likely(num_data_pages > 1)) {
512 		++mob->pt_level;
513 		BUG_ON(mob->pt_level > 2);
514 		save_pt_iter = pt_iter;
515 		num_pt_pages = vmw_mob_build_pt(&data_iter, num_data_pages,
516 						&pt_iter);
517 		data_iter = save_pt_iter;
518 		num_data_pages = num_pt_pages;
519 	}
520 
521 	mob->pt_root_page = vmw_piter_dma_addr(&save_pt_iter);
522 	ttm_bo_unreserve(bo);
523 }
524 
525 /*
526  * vmw_mob_destroy - Destroy a mob, unpopulating first if necessary.
527  *
528  * @mob:            Pointer to a mob to destroy.
529  */
530 void vmw_mob_destroy(struct vmw_mob *mob)
531 {
532 	if (mob->pt_bo) {
533 		ttm_bo_unpin(mob->pt_bo);
534 		ttm_bo_put(mob->pt_bo);
535 		mob->pt_bo = NULL;
536 	}
537 	kfree(mob);
538 }
539 
540 /*
541  * vmw_mob_unbind - Hide a mob from the device.
542  *
543  * @dev_priv:       Pointer to a device private.
544  * @mob_id:         Device id of the mob to unbind.
545  */
546 void vmw_mob_unbind(struct vmw_private *dev_priv,
547 		    struct vmw_mob *mob)
548 {
549 	struct {
550 		SVGA3dCmdHeader header;
551 		SVGA3dCmdDestroyGBMob body;
552 	} *cmd;
553 	int ret;
554 	struct ttm_buffer_object *bo = mob->pt_bo;
555 
556 	if (bo) {
557 		ret = ttm_bo_reserve(bo, false, true, NULL);
558 		/*
559 		 * Noone else should be using this buffer.
560 		 */
561 		BUG_ON(ret != 0);
562 	}
563 
564 	cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
565 	if (cmd) {
566 		cmd->header.id = SVGA_3D_CMD_DESTROY_GB_MOB;
567 		cmd->header.size = sizeof(cmd->body);
568 		cmd->body.mobid = mob->id;
569 		vmw_cmd_commit(dev_priv, sizeof(*cmd));
570 	}
571 
572 	if (bo) {
573 		vmw_bo_fence_single(bo, NULL);
574 		ttm_bo_unreserve(bo);
575 	}
576 	vmw_fifo_resource_dec(dev_priv);
577 }
578 
579 /*
580  * vmw_mob_bind - Make a mob visible to the device after first
581  *                populating it if necessary.
582  *
583  * @dev_priv:       Pointer to a device private.
584  * @mob:            Pointer to the mob we're making visible.
585  * @data_addr:      Array of DMA addresses to the data pages of the underlying
586  *                  buffer object.
587  * @num_data_pages: Number of data pages of the underlying buffer
588  *                  object.
589  * @mob_id:         Device id of the mob to bind
590  *
591  * This function is intended to be interfaced with the ttm_tt backend
592  * code.
593  */
594 int vmw_mob_bind(struct vmw_private *dev_priv,
595 		 struct vmw_mob *mob,
596 		 const struct vmw_sg_table *vsgt,
597 		 unsigned long num_data_pages,
598 		 int32_t mob_id)
599 {
600 	int ret;
601 	bool pt_set_up = false;
602 	struct vmw_piter data_iter;
603 	struct {
604 		SVGA3dCmdHeader header;
605 		SVGA3dCmdDefineGBMob64 body;
606 	} *cmd;
607 
608 	mob->id = mob_id;
609 	vmw_piter_start(&data_iter, vsgt, 0);
610 	if (unlikely(!vmw_piter_next(&data_iter)))
611 		return 0;
612 
613 	if (likely(num_data_pages == 1)) {
614 		mob->pt_level = VMW_MOBFMT_PTDEPTH_0;
615 		mob->pt_root_page = vmw_piter_dma_addr(&data_iter);
616 	} else if (vsgt->num_regions == 1) {
617 		mob->pt_level = SVGA3D_MOBFMT_RANGE;
618 		mob->pt_root_page = vmw_piter_dma_addr(&data_iter);
619 	} else if (unlikely(mob->pt_bo == NULL)) {
620 		ret = vmw_mob_pt_populate(dev_priv, mob);
621 		if (unlikely(ret != 0))
622 			return ret;
623 
624 		vmw_mob_pt_setup(mob, data_iter, num_data_pages);
625 		pt_set_up = true;
626 		mob->pt_level += VMW_MOBFMT_PTDEPTH_1 - SVGA3D_MOBFMT_PTDEPTH_1;
627 	}
628 
629 	vmw_fifo_resource_inc(dev_priv);
630 
631 	cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
632 	if (unlikely(cmd == NULL))
633 		goto out_no_cmd_space;
634 
635 	cmd->header.id = SVGA_3D_CMD_DEFINE_GB_MOB64;
636 	cmd->header.size = sizeof(cmd->body);
637 	cmd->body.mobid = mob_id;
638 	cmd->body.ptDepth = mob->pt_level;
639 	cmd->body.base = mob->pt_root_page >> PAGE_SHIFT;
640 	cmd->body.sizeInBytes = num_data_pages * PAGE_SIZE;
641 
642 	vmw_cmd_commit(dev_priv, sizeof(*cmd));
643 
644 	return 0;
645 
646 out_no_cmd_space:
647 	vmw_fifo_resource_dec(dev_priv);
648 	if (pt_set_up) {
649 		ttm_bo_unpin(mob->pt_bo);
650 		ttm_bo_put(mob->pt_bo);
651 		mob->pt_bo = NULL;
652 	}
653 
654 	return -ENOMEM;
655 }
656