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1/*
2 * Copyright © 2010 Daniel Vetter
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 */
24
25#include "drmP.h"
26#include "drm.h"
27#include "i915_drm.h"
28#include "i915_drv.h"
29#include "i915_trace.h"
30#include "intel_drv.h"
31
32/* PPGTT support for Sandybdrige/Gen6 and later */
33static void i915_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
34 unsigned first_entry,
35 unsigned num_entries)
36{
37 uint32_t *pt_vaddr;
38 uint32_t scratch_pte;
39 unsigned act_pd = first_entry / I915_PPGTT_PT_ENTRIES;
40 unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
41 unsigned last_pte, i;
42
43 scratch_pte = GEN6_PTE_ADDR_ENCODE(ppgtt->scratch_page_dma_addr);
44 scratch_pte |= GEN6_PTE_VALID | GEN6_PTE_CACHE_LLC;
45
46 while (num_entries) {
47 last_pte = first_pte + num_entries;
48 if (last_pte > I915_PPGTT_PT_ENTRIES)
49 last_pte = I915_PPGTT_PT_ENTRIES;
50
51 pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pd]);
52
53 for (i = first_pte; i < last_pte; i++)
54 pt_vaddr[i] = scratch_pte;
55
56 kunmap_atomic(pt_vaddr);
57
58 num_entries -= last_pte - first_pte;
59 first_pte = 0;
60 act_pd++;
61 }
62}
63
64int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
65{
66 struct drm_i915_private *dev_priv = dev->dev_private;
67 struct i915_hw_ppgtt *ppgtt;
68 unsigned first_pd_entry_in_global_pt;
69 int i;
70 int ret = -ENOMEM;
71
72 /* ppgtt PDEs reside in the global gtt pagetable, which has 512*1024
73 * entries. For aliasing ppgtt support we just steal them at the end for
74 * now. */
75 first_pd_entry_in_global_pt = 512*1024 - I915_PPGTT_PD_ENTRIES;
76
77 ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
78 if (!ppgtt)
79 return ret;
80
81 ppgtt->num_pd_entries = I915_PPGTT_PD_ENTRIES;
82 ppgtt->pt_pages = kzalloc(sizeof(struct page *)*ppgtt->num_pd_entries,
83 GFP_KERNEL);
84 if (!ppgtt->pt_pages)
85 goto err_ppgtt;
86
87 for (i = 0; i < ppgtt->num_pd_entries; i++) {
88 ppgtt->pt_pages[i] = alloc_page(GFP_KERNEL);
89 if (!ppgtt->pt_pages[i])
90 goto err_pt_alloc;
91 }
92
93 if (dev_priv->mm.gtt->needs_dmar) {
94 ppgtt->pt_dma_addr = kzalloc(sizeof(dma_addr_t)
95 *ppgtt->num_pd_entries,
96 GFP_KERNEL);
97 if (!ppgtt->pt_dma_addr)
98 goto err_pt_alloc;
99
100 for (i = 0; i < ppgtt->num_pd_entries; i++) {
101 dma_addr_t pt_addr;
102
103 pt_addr = pci_map_page(dev->pdev, ppgtt->pt_pages[i],
104 0, 4096,
105 PCI_DMA_BIDIRECTIONAL);
106
107 if (pci_dma_mapping_error(dev->pdev,
108 pt_addr)) {
109 ret = -EIO;
110 goto err_pd_pin;
111
112 }
113 ppgtt->pt_dma_addr[i] = pt_addr;
114 }
115 }
116
117 ppgtt->scratch_page_dma_addr = dev_priv->mm.gtt->scratch_page_dma;
118
119 i915_ppgtt_clear_range(ppgtt, 0,
120 ppgtt->num_pd_entries*I915_PPGTT_PT_ENTRIES);
121
122 ppgtt->pd_offset = (first_pd_entry_in_global_pt)*sizeof(uint32_t);
123
124 dev_priv->mm.aliasing_ppgtt = ppgtt;
125
126 return 0;
127
128err_pd_pin:
129 if (ppgtt->pt_dma_addr) {
130 for (i--; i >= 0; i--)
131 pci_unmap_page(dev->pdev, ppgtt->pt_dma_addr[i],
132 4096, PCI_DMA_BIDIRECTIONAL);
133 }
134err_pt_alloc:
135 kfree(ppgtt->pt_dma_addr);
136 for (i = 0; i < ppgtt->num_pd_entries; i++) {
137 if (ppgtt->pt_pages[i])
138 __free_page(ppgtt->pt_pages[i]);
139 }
140 kfree(ppgtt->pt_pages);
141err_ppgtt:
142 kfree(ppgtt);
143
144 return ret;
145}
146
147void i915_gem_cleanup_aliasing_ppgtt(struct drm_device *dev)
148{
149 struct drm_i915_private *dev_priv = dev->dev_private;
150 struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
151 int i;
152
153 if (!ppgtt)
154 return;
155
156 if (ppgtt->pt_dma_addr) {
157 for (i = 0; i < ppgtt->num_pd_entries; i++)
158 pci_unmap_page(dev->pdev, ppgtt->pt_dma_addr[i],
159 4096, PCI_DMA_BIDIRECTIONAL);
160 }
161
162 kfree(ppgtt->pt_dma_addr);
163 for (i = 0; i < ppgtt->num_pd_entries; i++)
164 __free_page(ppgtt->pt_pages[i]);
165 kfree(ppgtt->pt_pages);
166 kfree(ppgtt);
167}
168
169static void i915_ppgtt_insert_sg_entries(struct i915_hw_ppgtt *ppgtt,
170 struct scatterlist *sg_list,
171 unsigned sg_len,
172 unsigned first_entry,
173 uint32_t pte_flags)
174{
175 uint32_t *pt_vaddr, pte;
176 unsigned act_pd = first_entry / I915_PPGTT_PT_ENTRIES;
177 unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
178 unsigned i, j, m, segment_len;
179 dma_addr_t page_addr;
180 struct scatterlist *sg;
181
182 /* init sg walking */
183 sg = sg_list;
184 i = 0;
185 segment_len = sg_dma_len(sg) >> PAGE_SHIFT;
186 m = 0;
187
188 while (i < sg_len) {
189 pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pd]);
190
191 for (j = first_pte; j < I915_PPGTT_PT_ENTRIES; j++) {
192 page_addr = sg_dma_address(sg) + (m << PAGE_SHIFT);
193 pte = GEN6_PTE_ADDR_ENCODE(page_addr);
194 pt_vaddr[j] = pte | pte_flags;
195
196 /* grab the next page */
197 m++;
198 if (m == segment_len) {
199 sg = sg_next(sg);
200 i++;
201 if (i == sg_len)
202 break;
203
204 segment_len = sg_dma_len(sg) >> PAGE_SHIFT;
205 m = 0;
206 }
207 }
208
209 kunmap_atomic(pt_vaddr);
210
211 first_pte = 0;
212 act_pd++;
213 }
214}
215
216static void i915_ppgtt_insert_pages(struct i915_hw_ppgtt *ppgtt,
217 unsigned first_entry, unsigned num_entries,
218 struct page **pages, uint32_t pte_flags)
219{
220 uint32_t *pt_vaddr, pte;
221 unsigned act_pd = first_entry / I915_PPGTT_PT_ENTRIES;
222 unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
223 unsigned last_pte, i;
224 dma_addr_t page_addr;
225
226 while (num_entries) {
227 last_pte = first_pte + num_entries;
228 last_pte = min_t(unsigned, last_pte, I915_PPGTT_PT_ENTRIES);
229
230 pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pd]);
231
232 for (i = first_pte; i < last_pte; i++) {
233 page_addr = page_to_phys(*pages);
234 pte = GEN6_PTE_ADDR_ENCODE(page_addr);
235 pt_vaddr[i] = pte | pte_flags;
236
237 pages++;
238 }
239
240 kunmap_atomic(pt_vaddr);
241
242 num_entries -= last_pte - first_pte;
243 first_pte = 0;
244 act_pd++;
245 }
246}
247
248void i915_ppgtt_bind_object(struct i915_hw_ppgtt *ppgtt,
249 struct drm_i915_gem_object *obj,
250 enum i915_cache_level cache_level)
251{
252 struct drm_device *dev = obj->base.dev;
253 struct drm_i915_private *dev_priv = dev->dev_private;
254 uint32_t pte_flags = GEN6_PTE_VALID;
255
256 switch (cache_level) {
257 case I915_CACHE_LLC_MLC:
258 pte_flags |= GEN6_PTE_CACHE_LLC_MLC;
259 break;
260 case I915_CACHE_LLC:
261 pte_flags |= GEN6_PTE_CACHE_LLC;
262 break;
263 case I915_CACHE_NONE:
264 pte_flags |= GEN6_PTE_UNCACHED;
265 break;
266 default:
267 BUG();
268 }
269
270 if (obj->sg_table) {
271 i915_ppgtt_insert_sg_entries(ppgtt,
272 obj->sg_table->sgl,
273 obj->sg_table->nents,
274 obj->gtt_space->start >> PAGE_SHIFT,
275 pte_flags);
276 } else if (dev_priv->mm.gtt->needs_dmar) {
277 BUG_ON(!obj->sg_list);
278
279 i915_ppgtt_insert_sg_entries(ppgtt,
280 obj->sg_list,
281 obj->num_sg,
282 obj->gtt_space->start >> PAGE_SHIFT,
283 pte_flags);
284 } else
285 i915_ppgtt_insert_pages(ppgtt,
286 obj->gtt_space->start >> PAGE_SHIFT,
287 obj->base.size >> PAGE_SHIFT,
288 obj->pages,
289 pte_flags);
290}
291
292void i915_ppgtt_unbind_object(struct i915_hw_ppgtt *ppgtt,
293 struct drm_i915_gem_object *obj)
294{
295 i915_ppgtt_clear_range(ppgtt,
296 obj->gtt_space->start >> PAGE_SHIFT,
297 obj->base.size >> PAGE_SHIFT);
298}
299
300/* XXX kill agp_type! */
301static unsigned int cache_level_to_agp_type(struct drm_device *dev,
302 enum i915_cache_level cache_level)
303{
304 switch (cache_level) {
305 case I915_CACHE_LLC_MLC:
306 if (INTEL_INFO(dev)->gen >= 6)
307 return AGP_USER_CACHED_MEMORY_LLC_MLC;
308 /* Older chipsets do not have this extra level of CPU
309 * cacheing, so fallthrough and request the PTE simply
310 * as cached.
311 */
312 case I915_CACHE_LLC:
313 return AGP_USER_CACHED_MEMORY;
314 default:
315 case I915_CACHE_NONE:
316 return AGP_USER_MEMORY;
317 }
318}
319
320static bool do_idling(struct drm_i915_private *dev_priv)
321{
322 bool ret = dev_priv->mm.interruptible;
323
324 if (unlikely(dev_priv->mm.gtt->do_idle_maps)) {
325 dev_priv->mm.interruptible = false;
326 if (i915_gpu_idle(dev_priv->dev)) {
327 DRM_ERROR("Couldn't idle GPU\n");
328 /* Wait a bit, in hopes it avoids the hang */
329 udelay(10);
330 }
331 }
332
333 return ret;
334}
335
336static void undo_idling(struct drm_i915_private *dev_priv, bool interruptible)
337{
338 if (unlikely(dev_priv->mm.gtt->do_idle_maps))
339 dev_priv->mm.interruptible = interruptible;
340}
341
342void i915_gem_restore_gtt_mappings(struct drm_device *dev)
343{
344 struct drm_i915_private *dev_priv = dev->dev_private;
345 struct drm_i915_gem_object *obj;
346
347 /* First fill our portion of the GTT with scratch pages */
348 intel_gtt_clear_range(dev_priv->mm.gtt_start / PAGE_SIZE,
349 (dev_priv->mm.gtt_end - dev_priv->mm.gtt_start) / PAGE_SIZE);
350
351 list_for_each_entry(obj, &dev_priv->mm.gtt_list, gtt_list) {
352 i915_gem_clflush_object(obj);
353 i915_gem_gtt_bind_object(obj, obj->cache_level);
354 }
355
356 intel_gtt_chipset_flush();
357}
358
359int i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj)
360{
361 struct drm_device *dev = obj->base.dev;
362 struct drm_i915_private *dev_priv = dev->dev_private;
363
364 if (dev_priv->mm.gtt->needs_dmar)
365 return intel_gtt_map_memory(obj->pages,
366 obj->base.size >> PAGE_SHIFT,
367 &obj->sg_list,
368 &obj->num_sg);
369 else
370 return 0;
371}
372
373void i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj,
374 enum i915_cache_level cache_level)
375{
376 struct drm_device *dev = obj->base.dev;
377 struct drm_i915_private *dev_priv = dev->dev_private;
378 unsigned int agp_type = cache_level_to_agp_type(dev, cache_level);
379
380 if (obj->sg_table) {
381 intel_gtt_insert_sg_entries(obj->sg_table->sgl,
382 obj->sg_table->nents,
383 obj->gtt_space->start >> PAGE_SHIFT,
384 agp_type);
385 } else if (dev_priv->mm.gtt->needs_dmar) {
386 BUG_ON(!obj->sg_list);
387
388 intel_gtt_insert_sg_entries(obj->sg_list,
389 obj->num_sg,
390 obj->gtt_space->start >> PAGE_SHIFT,
391 agp_type);
392 } else
393 intel_gtt_insert_pages(obj->gtt_space->start >> PAGE_SHIFT,
394 obj->base.size >> PAGE_SHIFT,
395 obj->pages,
396 agp_type);
397
398 obj->has_global_gtt_mapping = 1;
399}
400
401void i915_gem_gtt_unbind_object(struct drm_i915_gem_object *obj)
402{
403 intel_gtt_clear_range(obj->gtt_space->start >> PAGE_SHIFT,
404 obj->base.size >> PAGE_SHIFT);
405
406 obj->has_global_gtt_mapping = 0;
407}
408
409void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj)
410{
411 struct drm_device *dev = obj->base.dev;
412 struct drm_i915_private *dev_priv = dev->dev_private;
413 bool interruptible;
414
415 interruptible = do_idling(dev_priv);
416
417 if (obj->sg_list) {
418 intel_gtt_unmap_memory(obj->sg_list, obj->num_sg);
419 obj->sg_list = NULL;
420 }
421
422 undo_idling(dev_priv, interruptible);
423}
424
425void i915_gem_init_global_gtt(struct drm_device *dev,
426 unsigned long start,
427 unsigned long mappable_end,
428 unsigned long end)
429{
430 drm_i915_private_t *dev_priv = dev->dev_private;
431
432 /* Substract the guard page ... */
433 drm_mm_init(&dev_priv->mm.gtt_space, start, end - start - PAGE_SIZE);
434
435 dev_priv->mm.gtt_start = start;
436 dev_priv->mm.gtt_mappable_end = mappable_end;
437 dev_priv->mm.gtt_end = end;
438 dev_priv->mm.gtt_total = end - start;
439 dev_priv->mm.mappable_gtt_total = min(end, mappable_end) - start;
440
441 /* ... but ensure that we clear the entire range. */
442 intel_gtt_clear_range(start / PAGE_SIZE, (end-start) / PAGE_SIZE);
443}
1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2010 Daniel Vetter
4 * Copyright © 2020 Intel Corporation
5 */
6
7#include <linux/slab.h> /* fault-inject.h is not standalone! */
8
9#include <linux/fault-inject.h>
10#include <linux/log2.h>
11#include <linux/random.h>
12#include <linux/seq_file.h>
13#include <linux/stop_machine.h>
14
15#include <asm/set_memory.h>
16#include <asm/smp.h>
17
18#include "display/intel_frontbuffer.h"
19#include "gt/intel_gt.h"
20#include "gt/intel_gt_requests.h"
21
22#include "i915_drv.h"
23#include "i915_gem_evict.h"
24#include "i915_scatterlist.h"
25#include "i915_trace.h"
26#include "i915_vgpu.h"
27
28int i915_gem_gtt_prepare_pages(struct drm_i915_gem_object *obj,
29 struct sg_table *pages)
30{
31 do {
32 if (dma_map_sg_attrs(obj->base.dev->dev,
33 pages->sgl, pages->nents,
34 DMA_BIDIRECTIONAL,
35 DMA_ATTR_SKIP_CPU_SYNC |
36 DMA_ATTR_NO_KERNEL_MAPPING |
37 DMA_ATTR_NO_WARN))
38 return 0;
39
40 /*
41 * If the DMA remap fails, one cause can be that we have
42 * too many objects pinned in a small remapping table,
43 * such as swiotlb. Incrementally purge all other objects and
44 * try again - if there are no more pages to remove from
45 * the DMA remapper, i915_gem_shrink will return 0.
46 */
47 GEM_BUG_ON(obj->mm.pages == pages);
48 } while (i915_gem_shrink(NULL, to_i915(obj->base.dev),
49 obj->base.size >> PAGE_SHIFT, NULL,
50 I915_SHRINK_BOUND |
51 I915_SHRINK_UNBOUND));
52
53 return -ENOSPC;
54}
55
56void i915_gem_gtt_finish_pages(struct drm_i915_gem_object *obj,
57 struct sg_table *pages)
58{
59 struct drm_i915_private *i915 = to_i915(obj->base.dev);
60 struct i915_ggtt *ggtt = to_gt(i915)->ggtt;
61
62 /* XXX This does not prevent more requests being submitted! */
63 if (unlikely(ggtt->do_idle_maps))
64 /* Wait a bit, in the hope it avoids the hang */
65 usleep_range(100, 250);
66
67 dma_unmap_sg(i915->drm.dev, pages->sgl, pages->nents,
68 DMA_BIDIRECTIONAL);
69}
70
71/**
72 * i915_gem_gtt_reserve - reserve a node in an address_space (GTT)
73 * @vm: the &struct i915_address_space
74 * @ww: An optional struct i915_gem_ww_ctx.
75 * @node: the &struct drm_mm_node (typically i915_vma.mode)
76 * @size: how much space to allocate inside the GTT,
77 * must be #I915_GTT_PAGE_SIZE aligned
78 * @offset: where to insert inside the GTT,
79 * must be #I915_GTT_MIN_ALIGNMENT aligned, and the node
80 * (@offset + @size) must fit within the address space
81 * @color: color to apply to node, if this node is not from a VMA,
82 * color must be #I915_COLOR_UNEVICTABLE
83 * @flags: control search and eviction behaviour
84 *
85 * i915_gem_gtt_reserve() tries to insert the @node at the exact @offset inside
86 * the address space (using @size and @color). If the @node does not fit, it
87 * tries to evict any overlapping nodes from the GTT, including any
88 * neighbouring nodes if the colors do not match (to ensure guard pages between
89 * differing domains). See i915_gem_evict_for_node() for the gory details
90 * on the eviction algorithm. #PIN_NONBLOCK may used to prevent waiting on
91 * evicting active overlapping objects, and any overlapping node that is pinned
92 * or marked as unevictable will also result in failure.
93 *
94 * Returns: 0 on success, -ENOSPC if no suitable hole is found, -EINTR if
95 * asked to wait for eviction and interrupted.
96 */
97int i915_gem_gtt_reserve(struct i915_address_space *vm,
98 struct i915_gem_ww_ctx *ww,
99 struct drm_mm_node *node,
100 u64 size, u64 offset, unsigned long color,
101 unsigned int flags)
102{
103 int err;
104
105 GEM_BUG_ON(!size);
106 GEM_BUG_ON(!IS_ALIGNED(size, I915_GTT_PAGE_SIZE));
107 GEM_BUG_ON(!IS_ALIGNED(offset, I915_GTT_MIN_ALIGNMENT));
108 GEM_BUG_ON(range_overflows(offset, size, vm->total));
109 GEM_BUG_ON(vm == &to_gt(vm->i915)->ggtt->alias->vm);
110 GEM_BUG_ON(drm_mm_node_allocated(node));
111
112 node->size = size;
113 node->start = offset;
114 node->color = color;
115
116 err = drm_mm_reserve_node(&vm->mm, node);
117 if (err != -ENOSPC)
118 return err;
119
120 if (flags & PIN_NOEVICT)
121 return -ENOSPC;
122
123 err = i915_gem_evict_for_node(vm, ww, node, flags);
124 if (err == 0)
125 err = drm_mm_reserve_node(&vm->mm, node);
126
127 return err;
128}
129
130static u64 random_offset(u64 start, u64 end, u64 len, u64 align)
131{
132 u64 range, addr;
133
134 GEM_BUG_ON(range_overflows(start, len, end));
135 GEM_BUG_ON(round_up(start, align) > round_down(end - len, align));
136
137 range = round_down(end - len, align) - round_up(start, align);
138 if (range) {
139 if (sizeof(unsigned long) == sizeof(u64)) {
140 addr = get_random_u64();
141 } else {
142 addr = get_random_u32();
143 if (range > U32_MAX) {
144 addr <<= 32;
145 addr |= get_random_u32();
146 }
147 }
148 div64_u64_rem(addr, range, &addr);
149 start += addr;
150 }
151
152 return round_up(start, align);
153}
154
155/**
156 * i915_gem_gtt_insert - insert a node into an address_space (GTT)
157 * @vm: the &struct i915_address_space
158 * @ww: An optional struct i915_gem_ww_ctx.
159 * @node: the &struct drm_mm_node (typically i915_vma.node)
160 * @size: how much space to allocate inside the GTT,
161 * must be #I915_GTT_PAGE_SIZE aligned
162 * @alignment: required alignment of starting offset, may be 0 but
163 * if specified, this must be a power-of-two and at least
164 * #I915_GTT_MIN_ALIGNMENT
165 * @color: color to apply to node
166 * @start: start of any range restriction inside GTT (0 for all),
167 * must be #I915_GTT_PAGE_SIZE aligned
168 * @end: end of any range restriction inside GTT (U64_MAX for all),
169 * must be #I915_GTT_PAGE_SIZE aligned if not U64_MAX
170 * @flags: control search and eviction behaviour
171 *
172 * i915_gem_gtt_insert() first searches for an available hole into which
173 * is can insert the node. The hole address is aligned to @alignment and
174 * its @size must then fit entirely within the [@start, @end] bounds. The
175 * nodes on either side of the hole must match @color, or else a guard page
176 * will be inserted between the two nodes (or the node evicted). If no
177 * suitable hole is found, first a victim is randomly selected and tested
178 * for eviction, otherwise then the LRU list of objects within the GTT
179 * is scanned to find the first set of replacement nodes to create the hole.
180 * Those old overlapping nodes are evicted from the GTT (and so must be
181 * rebound before any future use). Any node that is currently pinned cannot
182 * be evicted (see i915_vma_pin()). Similar if the node's VMA is currently
183 * active and #PIN_NONBLOCK is specified, that node is also skipped when
184 * searching for an eviction candidate. See i915_gem_evict_something() for
185 * the gory details on the eviction algorithm.
186 *
187 * Returns: 0 on success, -ENOSPC if no suitable hole is found, -EINTR if
188 * asked to wait for eviction and interrupted.
189 */
190int i915_gem_gtt_insert(struct i915_address_space *vm,
191 struct i915_gem_ww_ctx *ww,
192 struct drm_mm_node *node,
193 u64 size, u64 alignment, unsigned long color,
194 u64 start, u64 end, unsigned int flags)
195{
196 enum drm_mm_insert_mode mode;
197 u64 offset;
198 int err;
199
200 lockdep_assert_held(&vm->mutex);
201
202 GEM_BUG_ON(!size);
203 GEM_BUG_ON(!IS_ALIGNED(size, I915_GTT_PAGE_SIZE));
204 GEM_BUG_ON(alignment && !is_power_of_2(alignment));
205 GEM_BUG_ON(alignment && !IS_ALIGNED(alignment, I915_GTT_MIN_ALIGNMENT));
206 GEM_BUG_ON(start >= end);
207 GEM_BUG_ON(start > 0 && !IS_ALIGNED(start, I915_GTT_PAGE_SIZE));
208 GEM_BUG_ON(end < U64_MAX && !IS_ALIGNED(end, I915_GTT_PAGE_SIZE));
209 GEM_BUG_ON(vm == &to_gt(vm->i915)->ggtt->alias->vm);
210 GEM_BUG_ON(drm_mm_node_allocated(node));
211
212 if (unlikely(range_overflows(start, size, end)))
213 return -ENOSPC;
214
215 if (unlikely(round_up(start, alignment) > round_down(end - size, alignment)))
216 return -ENOSPC;
217
218 mode = DRM_MM_INSERT_BEST;
219 if (flags & PIN_HIGH)
220 mode = DRM_MM_INSERT_HIGHEST;
221 if (flags & PIN_MAPPABLE)
222 mode = DRM_MM_INSERT_LOW;
223
224 /* We only allocate in PAGE_SIZE/GTT_PAGE_SIZE (4096) chunks,
225 * so we know that we always have a minimum alignment of 4096.
226 * The drm_mm range manager is optimised to return results
227 * with zero alignment, so where possible use the optimal
228 * path.
229 */
230 BUILD_BUG_ON(I915_GTT_MIN_ALIGNMENT > I915_GTT_PAGE_SIZE);
231 if (alignment <= I915_GTT_MIN_ALIGNMENT)
232 alignment = 0;
233
234 err = drm_mm_insert_node_in_range(&vm->mm, node,
235 size, alignment, color,
236 start, end, mode);
237 if (err != -ENOSPC)
238 return err;
239
240 if (mode & DRM_MM_INSERT_ONCE) {
241 err = drm_mm_insert_node_in_range(&vm->mm, node,
242 size, alignment, color,
243 start, end,
244 DRM_MM_INSERT_BEST);
245 if (err != -ENOSPC)
246 return err;
247 }
248
249 if (flags & PIN_NOEVICT)
250 return -ENOSPC;
251
252 /*
253 * No free space, pick a slot at random.
254 *
255 * There is a pathological case here using a GTT shared between
256 * mmap and GPU (i.e. ggtt/aliasing_ppgtt but not full-ppgtt):
257 *
258 * |<-- 256 MiB aperture -->||<-- 1792 MiB unmappable -->|
259 * (64k objects) (448k objects)
260 *
261 * Now imagine that the eviction LRU is ordered top-down (just because
262 * pathology meets real life), and that we need to evict an object to
263 * make room inside the aperture. The eviction scan then has to walk
264 * the 448k list before it finds one within range. And now imagine that
265 * it has to search for a new hole between every byte inside the memcpy,
266 * for several simultaneous clients.
267 *
268 * On a full-ppgtt system, if we have run out of available space, there
269 * will be lots and lots of objects in the eviction list! Again,
270 * searching that LRU list may be slow if we are also applying any
271 * range restrictions (e.g. restriction to low 4GiB) and so, for
272 * simplicity and similarilty between different GTT, try the single
273 * random replacement first.
274 */
275 offset = random_offset(start, end,
276 size, alignment ?: I915_GTT_MIN_ALIGNMENT);
277 err = i915_gem_gtt_reserve(vm, ww, node, size, offset, color, flags);
278 if (err != -ENOSPC)
279 return err;
280
281 if (flags & PIN_NOSEARCH)
282 return -ENOSPC;
283
284 /* Randomly selected placement is pinned, do a search */
285 err = i915_gem_evict_something(vm, ww, size, alignment, color,
286 start, end, flags);
287 if (err)
288 return err;
289
290 return drm_mm_insert_node_in_range(&vm->mm, node,
291 size, alignment, color,
292 start, end, DRM_MM_INSERT_EVICT);
293}
294
295#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
296#include "selftests/i915_gem_gtt.c"
297#endif