1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2021 Intel Corporation
4 */
5
6#include <linux/slab.h>
7
8#include <drm/drm_buddy.h>
9#include <drm/drm_print.h>
10#include <drm/ttm/ttm_placement.h>
11#include <drm/ttm/ttm_bo.h>
12
13#include "i915_ttm_buddy_manager.h"
14
15#include "i915_gem.h"
16
17struct i915_ttm_buddy_manager {
18 struct ttm_resource_manager manager;
19 struct drm_buddy mm;
20 struct list_head reserved;
21 struct mutex lock;
22 unsigned long visible_size;
23 unsigned long visible_avail;
24 unsigned long visible_reserved;
25 u64 default_page_size;
26};
27
28static struct i915_ttm_buddy_manager *
29to_buddy_manager(struct ttm_resource_manager *man)
30{
31 return container_of(man, struct i915_ttm_buddy_manager, manager);
32}
33
34static int i915_ttm_buddy_man_alloc(struct ttm_resource_manager *man,
35 struct ttm_buffer_object *bo,
36 const struct ttm_place *place,
37 struct ttm_resource **res)
38{
39 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
40 struct i915_ttm_buddy_resource *bman_res;
41 struct drm_buddy *mm = &bman->mm;
42 unsigned long n_pages, lpfn;
43 u64 min_page_size;
44 u64 size;
45 int err;
46
47 lpfn = place->lpfn;
48 if (!lpfn)
49 lpfn = man->size;
50
51 bman_res = kzalloc(sizeof(*bman_res), GFP_KERNEL);
52 if (!bman_res)
53 return -ENOMEM;
54
55 ttm_resource_init(bo, place, res: &bman_res->base);
56 INIT_LIST_HEAD(list: &bman_res->blocks);
57 bman_res->mm = mm;
58
59 if (place->flags & TTM_PL_FLAG_TOPDOWN)
60 bman_res->flags |= DRM_BUDDY_TOPDOWN_ALLOCATION;
61
62 if (place->flags & TTM_PL_FLAG_CONTIGUOUS)
63 bman_res->flags |= DRM_BUDDY_CONTIGUOUS_ALLOCATION;
64
65 if (place->fpfn || lpfn != man->size)
66 bman_res->flags |= DRM_BUDDY_RANGE_ALLOCATION;
67
68 GEM_BUG_ON(!bman_res->base.size);
69 size = bman_res->base.size;
70
71 min_page_size = bman->default_page_size;
72 if (bo->page_alignment)
73 min_page_size = bo->page_alignment << PAGE_SHIFT;
74
75 GEM_BUG_ON(min_page_size < mm->chunk_size);
76 GEM_BUG_ON(!IS_ALIGNED(size, min_page_size));
77
78 if (size > lpfn << PAGE_SHIFT) {
79 err = -E2BIG;
80 goto err_free_res;
81 }
82
83 n_pages = size >> ilog2(mm->chunk_size);
84
85 mutex_lock(&bman->lock);
86 if (lpfn <= bman->visible_size && n_pages > bman->visible_avail) {
87 mutex_unlock(lock: &bman->lock);
88 err = -ENOSPC;
89 goto err_free_res;
90 }
91
92 err = drm_buddy_alloc_blocks(mm, start: (u64)place->fpfn << PAGE_SHIFT,
93 end: (u64)lpfn << PAGE_SHIFT,
94 size: (u64)n_pages << PAGE_SHIFT,
95 min_page_size,
96 blocks: &bman_res->blocks,
97 flags: bman_res->flags);
98 if (unlikely(err))
99 goto err_free_blocks;
100
101 if (lpfn <= bman->visible_size) {
102 bman_res->used_visible_size = PFN_UP(bman_res->base.size);
103 } else {
104 struct drm_buddy_block *block;
105
106 list_for_each_entry(block, &bman_res->blocks, link) {
107 unsigned long start =
108 drm_buddy_block_offset(block) >> PAGE_SHIFT;
109
110 if (start < bman->visible_size) {
111 unsigned long end = start +
112 (drm_buddy_block_size(mm, block) >> PAGE_SHIFT);
113
114 bman_res->used_visible_size +=
115 min(end, bman->visible_size) - start;
116 }
117 }
118 }
119
120 if (bman_res->used_visible_size)
121 bman->visible_avail -= bman_res->used_visible_size;
122
123 mutex_unlock(lock: &bman->lock);
124
125 *res = &bman_res->base;
126 return 0;
127
128err_free_blocks:
129 drm_buddy_free_list(mm, objects: &bman_res->blocks, flags: 0);
130 mutex_unlock(lock: &bman->lock);
131err_free_res:
132 ttm_resource_fini(man, res: &bman_res->base);
133 kfree(objp: bman_res);
134 return err;
135}
136
137static void i915_ttm_buddy_man_free(struct ttm_resource_manager *man,
138 struct ttm_resource *res)
139{
140 struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
141 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
142
143 mutex_lock(&bman->lock);
144 drm_buddy_free_list(mm: &bman->mm, objects: &bman_res->blocks, flags: 0);
145 bman->visible_avail += bman_res->used_visible_size;
146 mutex_unlock(lock: &bman->lock);
147
148 ttm_resource_fini(man, res);
149 kfree(objp: bman_res);
150}
151
152static bool i915_ttm_buddy_man_intersects(struct ttm_resource_manager *man,
153 struct ttm_resource *res,
154 const struct ttm_place *place,
155 size_t size)
156{
157 struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
158 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
159 struct drm_buddy *mm = &bman->mm;
160 struct drm_buddy_block *block;
161
162 if (!place->fpfn && !place->lpfn)
163 return true;
164
165 GEM_BUG_ON(!place->lpfn);
166
167 /*
168 * If we just want something mappable then we can quickly check
169 * if the current victim resource is using any of the CPU
170 * visible portion.
171 */
172 if (!place->fpfn &&
173 place->lpfn == i915_ttm_buddy_man_visible_size(man))
174 return bman_res->used_visible_size > 0;
175
176 /* Check each drm buddy block individually */
177 list_for_each_entry(block, &bman_res->blocks, link) {
178 unsigned long fpfn =
179 drm_buddy_block_offset(block) >> PAGE_SHIFT;
180 unsigned long lpfn = fpfn +
181 (drm_buddy_block_size(mm, block) >> PAGE_SHIFT);
182
183 if (place->fpfn < lpfn && place->lpfn > fpfn)
184 return true;
185 }
186
187 return false;
188}
189
190static bool i915_ttm_buddy_man_compatible(struct ttm_resource_manager *man,
191 struct ttm_resource *res,
192 const struct ttm_place *place,
193 size_t size)
194{
195 struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
196 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
197 struct drm_buddy *mm = &bman->mm;
198 struct drm_buddy_block *block;
199
200 if (!place->fpfn && !place->lpfn)
201 return true;
202
203 GEM_BUG_ON(!place->lpfn);
204
205 if (!place->fpfn &&
206 place->lpfn == i915_ttm_buddy_man_visible_size(man))
207 return bman_res->used_visible_size == PFN_UP(res->size);
208
209 /* Check each drm buddy block individually */
210 list_for_each_entry(block, &bman_res->blocks, link) {
211 unsigned long fpfn =
212 drm_buddy_block_offset(block) >> PAGE_SHIFT;
213 unsigned long lpfn = fpfn +
214 (drm_buddy_block_size(mm, block) >> PAGE_SHIFT);
215
216 if (fpfn < place->fpfn || lpfn > place->lpfn)
217 return false;
218 }
219
220 return true;
221}
222
223static void i915_ttm_buddy_man_debug(struct ttm_resource_manager *man,
224 struct drm_printer *printer)
225{
226 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
227 struct drm_buddy_block *block;
228
229 mutex_lock(&bman->lock);
230 drm_printf(p: printer, f: "default_page_size: %lluKiB\n",
231 bman->default_page_size >> 10);
232 drm_printf(p: printer, f: "visible_avail: %lluMiB\n",
233 (u64)bman->visible_avail << PAGE_SHIFT >> 20);
234 drm_printf(p: printer, f: "visible_size: %lluMiB\n",
235 (u64)bman->visible_size << PAGE_SHIFT >> 20);
236 drm_printf(p: printer, f: "visible_reserved: %lluMiB\n",
237 (u64)bman->visible_reserved << PAGE_SHIFT >> 20);
238
239 drm_buddy_print(mm: &bman->mm, p: printer);
240
241 drm_printf(p: printer, f: "reserved:\n");
242 list_for_each_entry(block, &bman->reserved, link)
243 drm_buddy_block_print(mm: &bman->mm, block, p: printer);
244 mutex_unlock(lock: &bman->lock);
245}
246
247static const struct ttm_resource_manager_func i915_ttm_buddy_manager_func = {
248 .alloc = i915_ttm_buddy_man_alloc,
249 .free = i915_ttm_buddy_man_free,
250 .intersects = i915_ttm_buddy_man_intersects,
251 .compatible = i915_ttm_buddy_man_compatible,
252 .debug = i915_ttm_buddy_man_debug,
253};
254
255/**
256 * i915_ttm_buddy_man_init - Setup buddy allocator based ttm manager
257 * @bdev: The ttm device
258 * @type: Memory type we want to manage
259 * @use_tt: Set use_tt for the manager
260 * @size: The size in bytes to manage
261 * @visible_size: The CPU visible size in bytes to manage
262 * @default_page_size: The default minimum page size in bytes for allocations,
263 * this must be at least as large as @chunk_size, and can be overridden by
264 * setting the BO page_alignment, to be larger or smaller as needed.
265 * @chunk_size: The minimum page size in bytes for our allocations i.e
266 * order-zero
267 *
268 * Note that the starting address is assumed to be zero here, since this
269 * simplifies keeping the property where allocated blocks having natural
270 * power-of-two alignment. So long as the real starting address is some large
271 * power-of-two, or naturally start from zero, then this should be fine. Also
272 * the &i915_ttm_buddy_man_reserve interface can be used to preserve alignment
273 * if say there is some unusable range from the start of the region. We can
274 * revisit this in the future and make the interface accept an actual starting
275 * offset and let it take care of the rest.
276 *
277 * Note that if the @size is not aligned to the @chunk_size then we perform the
278 * required rounding to get the usable size. The final size in pages can be
279 * taken from &ttm_resource_manager.size.
280 *
281 * Return: 0 on success, negative error code on failure.
282 */
283int i915_ttm_buddy_man_init(struct ttm_device *bdev,
284 unsigned int type, bool use_tt,
285 u64 size, u64 visible_size, u64 default_page_size,
286 u64 chunk_size)
287{
288 struct ttm_resource_manager *man;
289 struct i915_ttm_buddy_manager *bman;
290 int err;
291
292 bman = kzalloc(sizeof(*bman), GFP_KERNEL);
293 if (!bman)
294 return -ENOMEM;
295
296 err = drm_buddy_init(mm: &bman->mm, size, chunk_size);
297 if (err)
298 goto err_free_bman;
299
300 mutex_init(&bman->lock);
301 INIT_LIST_HEAD(list: &bman->reserved);
302 GEM_BUG_ON(default_page_size < chunk_size);
303 bman->default_page_size = default_page_size;
304 bman->visible_size = visible_size >> PAGE_SHIFT;
305 bman->visible_avail = bman->visible_size;
306
307 man = &bman->manager;
308 man->use_tt = use_tt;
309 man->func = &i915_ttm_buddy_manager_func;
310 ttm_resource_manager_init(man, bdev, size: bman->mm.size >> PAGE_SHIFT);
311
312 ttm_resource_manager_set_used(man, used: true);
313 ttm_set_driver_manager(bdev, type, manager: man);
314
315 return 0;
316
317err_free_bman:
318 kfree(objp: bman);
319 return err;
320}
321
322/**
323 * i915_ttm_buddy_man_fini - Destroy the buddy allocator ttm manager
324 * @bdev: The ttm device
325 * @type: Memory type we want to manage
326 *
327 * Note that if we reserved anything with &i915_ttm_buddy_man_reserve, this will
328 * also be freed for us here.
329 *
330 * Return: 0 on success, negative error code on failure.
331 */
332int i915_ttm_buddy_man_fini(struct ttm_device *bdev, unsigned int type)
333{
334 struct ttm_resource_manager *man = ttm_manager_type(bdev, mem_type: type);
335 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
336 struct drm_buddy *mm = &bman->mm;
337 int ret;
338
339 ttm_resource_manager_set_used(man, used: false);
340
341 ret = ttm_resource_manager_evict_all(bdev, man);
342 if (ret)
343 return ret;
344
345 ttm_set_driver_manager(bdev, type, NULL);
346
347 mutex_lock(&bman->lock);
348 drm_buddy_free_list(mm, objects: &bman->reserved, flags: 0);
349 drm_buddy_fini(mm);
350 bman->visible_avail += bman->visible_reserved;
351 WARN_ON_ONCE(bman->visible_avail != bman->visible_size);
352 mutex_unlock(lock: &bman->lock);
353
354 ttm_resource_manager_cleanup(man);
355 kfree(objp: bman);
356
357 return 0;
358}
359
360/**
361 * i915_ttm_buddy_man_reserve - Reserve address range
362 * @man: The buddy allocator ttm manager
363 * @start: The offset in bytes, where the region start is assumed to be zero
364 * @size: The size in bytes
365 *
366 * Note that the starting address for the region is always assumed to be zero.
367 *
368 * Return: 0 on success, negative error code on failure.
369 */
370int i915_ttm_buddy_man_reserve(struct ttm_resource_manager *man,
371 u64 start, u64 size)
372{
373 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
374 struct drm_buddy *mm = &bman->mm;
375 unsigned long fpfn = start >> PAGE_SHIFT;
376 unsigned long flags = 0;
377 int ret;
378
379 flags |= DRM_BUDDY_RANGE_ALLOCATION;
380
381 mutex_lock(&bman->lock);
382 ret = drm_buddy_alloc_blocks(mm, start,
383 end: start + size,
384 size, min_page_size: mm->chunk_size,
385 blocks: &bman->reserved,
386 flags);
387
388 if (fpfn < bman->visible_size) {
389 unsigned long lpfn = fpfn + (size >> PAGE_SHIFT);
390 unsigned long visible = min(lpfn, bman->visible_size) - fpfn;
391
392 bman->visible_reserved += visible;
393 bman->visible_avail -= visible;
394 }
395 mutex_unlock(lock: &bman->lock);
396
397 return ret;
398}
399
400/**
401 * i915_ttm_buddy_man_visible_size - Return the size of the CPU visible portion
402 * in pages.
403 * @man: The buddy allocator ttm manager
404 */
405u64 i915_ttm_buddy_man_visible_size(struct ttm_resource_manager *man)
406{
407 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
408
409 return bman->visible_size;
410}
411
412/**
413 * i915_ttm_buddy_man_avail - Query the avail tracking for the manager.
414 *
415 * @man: The buddy allocator ttm manager
416 * @avail: The total available memory in pages for the entire manager.
417 * @visible_avail: The total available memory in pages for the CPU visible
418 * portion. Note that this will always give the same value as @avail on
419 * configurations that don't have a small BAR.
420 */
421void i915_ttm_buddy_man_avail(struct ttm_resource_manager *man,
422 u64 *avail, u64 *visible_avail)
423{
424 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
425
426 mutex_lock(&bman->lock);
427 *avail = bman->mm.avail >> PAGE_SHIFT;
428 *visible_avail = bman->visible_avail;
429 mutex_unlock(lock: &bman->lock);
430}
431
432#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
433void i915_ttm_buddy_man_force_visible_size(struct ttm_resource_manager *man,
434 u64 size)
435{
436 struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
437
438 bman->visible_size = size;
439}
440#endif
441

source code of linux/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c