Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 OR MIT */
2 : /**************************************************************************
3 : *
4 : * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
5 : * All Rights Reserved.
6 : *
7 : * Permission is hereby granted, free of charge, to any person obtaining a
8 : * copy of this software and associated documentation files (the
9 : * "Software"), to deal in the Software without restriction, including
10 : * without limitation the rights to use, copy, modify, merge, publish,
11 : * distribute, sub license, and/or sell copies of the Software, and to
12 : * permit persons to whom the Software is furnished to do so, subject to
13 : * the following conditions:
14 : *
15 : * The above copyright notice and this permission notice (including the
16 : * next paragraph) shall be included in all copies or substantial portions
17 : * of the Software.
18 : *
19 : * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 : * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 : * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
22 : * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
23 : * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
24 : * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
25 : * USE OR OTHER DEALINGS IN THE SOFTWARE.
26 : *
27 : **************************************************************************/
28 : /*
29 : * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30 : */
31 :
32 : #define pr_fmt(fmt) "[TTM] " fmt
33 :
34 : #include <drm/ttm/ttm_bo_driver.h>
35 : #include <drm/ttm/ttm_placement.h>
36 : #include <drm/drm_vma_manager.h>
37 : #include <drm/drm_drv.h>
38 : #include <drm/drm_managed.h>
39 : #include <linux/mm.h>
40 : #include <linux/pfn_t.h>
41 : #include <linux/rbtree.h>
42 : #include <linux/module.h>
43 : #include <linux/uaccess.h>
44 : #include <linux/mem_encrypt.h>
45 :
46 0 : static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
47 : struct vm_fault *vmf)
48 : {
49 0 : long err = 0;
50 :
51 : /*
52 : * Quick non-stalling check for idle.
53 : */
54 0 : if (dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_KERNEL))
55 : return 0;
56 :
57 : /*
58 : * If possible, avoid waiting for GPU with mmap_lock
59 : * held. We only do this if the fault allows retry and this
60 : * is the first attempt.
61 : */
62 0 : if (fault_flag_allow_retry_first(vmf->flags)) {
63 0 : if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
64 : return VM_FAULT_RETRY;
65 :
66 0 : ttm_bo_get(bo);
67 0 : mmap_read_unlock(vmf->vma->vm_mm);
68 0 : (void)dma_resv_wait_timeout(bo->base.resv,
69 : DMA_RESV_USAGE_KERNEL, true,
70 : MAX_SCHEDULE_TIMEOUT);
71 0 : dma_resv_unlock(bo->base.resv);
72 0 : ttm_bo_put(bo);
73 : return VM_FAULT_RETRY;
74 : }
75 :
76 : /*
77 : * Ordinary wait.
78 : */
79 0 : err = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_KERNEL, true,
80 : MAX_SCHEDULE_TIMEOUT);
81 0 : if (unlikely(err < 0)) {
82 0 : return (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
83 : VM_FAULT_NOPAGE;
84 : }
85 :
86 : return 0;
87 : }
88 :
89 : static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
90 : unsigned long page_offset)
91 : {
92 0 : struct ttm_device *bdev = bo->bdev;
93 :
94 0 : if (bdev->funcs->io_mem_pfn)
95 0 : return bdev->funcs->io_mem_pfn(bo, page_offset);
96 :
97 0 : return (bo->resource->bus.offset >> PAGE_SHIFT) + page_offset;
98 : }
99 :
100 : /**
101 : * ttm_bo_vm_reserve - Reserve a buffer object in a retryable vm callback
102 : * @bo: The buffer object
103 : * @vmf: The fault structure handed to the callback
104 : *
105 : * vm callbacks like fault() and *_mkwrite() allow for the mm_sem to be dropped
106 : * during long waits, and after the wait the callback will be restarted. This
107 : * is to allow other threads using the same virtual memory space concurrent
108 : * access to map(), unmap() completely unrelated buffer objects. TTM buffer
109 : * object reservations sometimes wait for GPU and should therefore be
110 : * considered long waits. This function reserves the buffer object interruptibly
111 : * taking this into account. Starvation is avoided by the vm system not
112 : * allowing too many repeated restarts.
113 : * This function is intended to be used in customized fault() and _mkwrite()
114 : * handlers.
115 : *
116 : * Return:
117 : * 0 on success and the bo was reserved.
118 : * VM_FAULT_RETRY if blocking wait.
119 : * VM_FAULT_NOPAGE if blocking wait and retrying was not allowed.
120 : */
121 0 : vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
122 : struct vm_fault *vmf)
123 : {
124 : /*
125 : * Work around locking order reversal in fault / nopfn
126 : * between mmap_lock and bo_reserve: Perform a trylock operation
127 : * for reserve, and if it fails, retry the fault after waiting
128 : * for the buffer to become unreserved.
129 : */
130 0 : if (unlikely(!dma_resv_trylock(bo->base.resv))) {
131 : /*
132 : * If the fault allows retry and this is the first
133 : * fault attempt, we try to release the mmap_lock
134 : * before waiting
135 : */
136 0 : if (fault_flag_allow_retry_first(vmf->flags)) {
137 0 : if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
138 0 : ttm_bo_get(bo);
139 0 : mmap_read_unlock(vmf->vma->vm_mm);
140 0 : if (!dma_resv_lock_interruptible(bo->base.resv,
141 : NULL))
142 0 : dma_resv_unlock(bo->base.resv);
143 0 : ttm_bo_put(bo);
144 : }
145 :
146 : return VM_FAULT_RETRY;
147 : }
148 :
149 0 : if (dma_resv_lock_interruptible(bo->base.resv, NULL))
150 : return VM_FAULT_NOPAGE;
151 : }
152 :
153 : /*
154 : * Refuse to fault imported pages. This should be handled
155 : * (if at all) by redirecting mmap to the exporter.
156 : */
157 0 : if (bo->ttm && (bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
158 0 : if (!(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE)) {
159 0 : dma_resv_unlock(bo->base.resv);
160 0 : return VM_FAULT_SIGBUS;
161 : }
162 : }
163 :
164 : return 0;
165 : }
166 : EXPORT_SYMBOL(ttm_bo_vm_reserve);
167 :
168 : /**
169 : * ttm_bo_vm_fault_reserved - TTM fault helper
170 : * @vmf: The struct vm_fault given as argument to the fault callback
171 : * @prot: The page protection to be used for this memory area.
172 : * @num_prefault: Maximum number of prefault pages. The caller may want to
173 : * specify this based on madvice settings and the size of the GPU object
174 : * backed by the memory.
175 : *
176 : * This function inserts one or more page table entries pointing to the
177 : * memory backing the buffer object, and then returns a return code
178 : * instructing the caller to retry the page access.
179 : *
180 : * Return:
181 : * VM_FAULT_NOPAGE on success or pending signal
182 : * VM_FAULT_SIGBUS on unspecified error
183 : * VM_FAULT_OOM on out-of-memory
184 : * VM_FAULT_RETRY if retryable wait
185 : */
186 0 : vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
187 : pgprot_t prot,
188 : pgoff_t num_prefault)
189 : {
190 0 : struct vm_area_struct *vma = vmf->vma;
191 0 : struct ttm_buffer_object *bo = vma->vm_private_data;
192 0 : struct ttm_device *bdev = bo->bdev;
193 : unsigned long page_offset;
194 : unsigned long page_last;
195 : unsigned long pfn;
196 0 : struct ttm_tt *ttm = NULL;
197 : struct page *page;
198 : int err;
199 : pgoff_t i;
200 0 : vm_fault_t ret = VM_FAULT_NOPAGE;
201 0 : unsigned long address = vmf->address;
202 :
203 : /*
204 : * Wait for buffer data in transit, due to a pipelined
205 : * move.
206 : */
207 0 : ret = ttm_bo_vm_fault_idle(bo, vmf);
208 0 : if (unlikely(ret != 0))
209 : return ret;
210 :
211 0 : err = ttm_mem_io_reserve(bdev, bo->resource);
212 0 : if (unlikely(err != 0))
213 : return VM_FAULT_SIGBUS;
214 :
215 0 : page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
216 0 : vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node);
217 0 : page_last = vma_pages(vma) + vma->vm_pgoff -
218 0 : drm_vma_node_start(&bo->base.vma_node);
219 :
220 0 : if (unlikely(page_offset >= bo->resource->num_pages))
221 : return VM_FAULT_SIGBUS;
222 :
223 0 : prot = ttm_io_prot(bo, bo->resource, prot);
224 0 : if (!bo->resource->bus.is_iomem) {
225 0 : struct ttm_operation_ctx ctx = {
226 : .interruptible = false,
227 : .no_wait_gpu = false,
228 : .force_alloc = true
229 : };
230 :
231 0 : ttm = bo->ttm;
232 0 : if (ttm_tt_populate(bdev, bo->ttm, &ctx))
233 0 : return VM_FAULT_OOM;
234 : } else {
235 : /* Iomem should not be marked encrypted */
236 : prot = pgprot_decrypted(prot);
237 : }
238 :
239 : /*
240 : * Speculatively prefault a number of pages. Only error on
241 : * first page.
242 : */
243 0 : for (i = 0; i < num_prefault; ++i) {
244 0 : if (bo->resource->bus.is_iomem) {
245 : pfn = ttm_bo_io_mem_pfn(bo, page_offset);
246 : } else {
247 0 : page = ttm->pages[page_offset];
248 0 : if (unlikely(!page && i == 0)) {
249 : return VM_FAULT_OOM;
250 0 : } else if (unlikely(!page)) {
251 : break;
252 : }
253 0 : pfn = page_to_pfn(page);
254 : }
255 :
256 : /*
257 : * Note that the value of @prot at this point may differ from
258 : * the value of @vma->vm_page_prot in the caching- and
259 : * encryption bits. This is because the exact location of the
260 : * data may not be known at mmap() time and may also change
261 : * at arbitrary times while the data is mmap'ed.
262 : * See vmf_insert_mixed_prot() for a discussion.
263 : */
264 0 : ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
265 :
266 : /* Never error on prefaulted PTEs */
267 0 : if (unlikely((ret & VM_FAULT_ERROR))) {
268 0 : if (i == 0)
269 : return VM_FAULT_NOPAGE;
270 : else
271 : break;
272 : }
273 :
274 0 : address += PAGE_SIZE;
275 0 : if (unlikely(++page_offset >= page_last))
276 : break;
277 : }
278 : return ret;
279 : }
280 : EXPORT_SYMBOL(ttm_bo_vm_fault_reserved);
281 :
282 0 : static void ttm_bo_release_dummy_page(struct drm_device *dev, void *res)
283 : {
284 0 : struct page *dummy_page = (struct page *)res;
285 :
286 0 : __free_page(dummy_page);
287 0 : }
288 :
289 0 : vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot)
290 : {
291 0 : struct vm_area_struct *vma = vmf->vma;
292 0 : struct ttm_buffer_object *bo = vma->vm_private_data;
293 0 : struct drm_device *ddev = bo->base.dev;
294 0 : vm_fault_t ret = VM_FAULT_NOPAGE;
295 : unsigned long address;
296 : unsigned long pfn;
297 : struct page *page;
298 :
299 : /* Allocate new dummy page to map all the VA range in this VMA to it*/
300 0 : page = alloc_page(GFP_KERNEL | __GFP_ZERO);
301 0 : if (!page)
302 : return VM_FAULT_OOM;
303 :
304 : /* Set the page to be freed using drmm release action */
305 0 : if (drmm_add_action_or_reset(ddev, ttm_bo_release_dummy_page, page))
306 : return VM_FAULT_OOM;
307 :
308 0 : pfn = page_to_pfn(page);
309 :
310 : /* Prefault the entire VMA range right away to avoid further faults */
311 0 : for (address = vma->vm_start; address < vma->vm_end;
312 0 : address += PAGE_SIZE)
313 0 : ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
314 :
315 : return ret;
316 : }
317 : EXPORT_SYMBOL(ttm_bo_vm_dummy_page);
318 :
319 0 : vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
320 : {
321 0 : struct vm_area_struct *vma = vmf->vma;
322 : pgprot_t prot;
323 0 : struct ttm_buffer_object *bo = vma->vm_private_data;
324 0 : struct drm_device *ddev = bo->base.dev;
325 : vm_fault_t ret;
326 : int idx;
327 :
328 0 : ret = ttm_bo_vm_reserve(bo, vmf);
329 0 : if (ret)
330 : return ret;
331 :
332 0 : prot = vma->vm_page_prot;
333 0 : if (drm_dev_enter(ddev, &idx)) {
334 0 : ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT);
335 0 : drm_dev_exit(idx);
336 : } else {
337 0 : ret = ttm_bo_vm_dummy_page(vmf, prot);
338 : }
339 0 : if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
340 : return ret;
341 :
342 0 : dma_resv_unlock(bo->base.resv);
343 :
344 0 : return ret;
345 : }
346 : EXPORT_SYMBOL(ttm_bo_vm_fault);
347 :
348 0 : void ttm_bo_vm_open(struct vm_area_struct *vma)
349 : {
350 0 : struct ttm_buffer_object *bo = vma->vm_private_data;
351 :
352 0 : WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
353 :
354 0 : ttm_bo_get(bo);
355 0 : }
356 : EXPORT_SYMBOL(ttm_bo_vm_open);
357 :
358 0 : void ttm_bo_vm_close(struct vm_area_struct *vma)
359 : {
360 0 : struct ttm_buffer_object *bo = vma->vm_private_data;
361 :
362 0 : ttm_bo_put(bo);
363 0 : vma->vm_private_data = NULL;
364 0 : }
365 : EXPORT_SYMBOL(ttm_bo_vm_close);
366 :
367 0 : static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
368 : unsigned long offset,
369 : uint8_t *buf, int len, int write)
370 : {
371 0 : unsigned long page = offset >> PAGE_SHIFT;
372 0 : unsigned long bytes_left = len;
373 : int ret;
374 :
375 : /* Copy a page at a time, that way no extra virtual address
376 : * mapping is needed
377 : */
378 0 : offset -= page << PAGE_SHIFT;
379 : do {
380 0 : unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
381 : struct ttm_bo_kmap_obj map;
382 : void *ptr;
383 : bool is_iomem;
384 :
385 0 : ret = ttm_bo_kmap(bo, page, 1, &map);
386 0 : if (ret)
387 0 : return ret;
388 :
389 0 : ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
390 0 : WARN_ON_ONCE(is_iomem);
391 0 : if (write)
392 0 : memcpy(ptr, buf, bytes);
393 : else
394 0 : memcpy(buf, ptr, bytes);
395 0 : ttm_bo_kunmap(&map);
396 :
397 0 : page++;
398 0 : buf += bytes;
399 0 : bytes_left -= bytes;
400 0 : offset = 0;
401 0 : } while (bytes_left);
402 :
403 : return len;
404 : }
405 :
406 0 : int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
407 : void *buf, int len, int write)
408 : {
409 0 : struct ttm_buffer_object *bo = vma->vm_private_data;
410 0 : unsigned long offset = (addr) - vma->vm_start +
411 0 : ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))
412 0 : << PAGE_SHIFT);
413 : int ret;
414 :
415 0 : if (len < 1 || (offset + len) >> PAGE_SHIFT > bo->resource->num_pages)
416 : return -EIO;
417 :
418 0 : ret = ttm_bo_reserve(bo, true, false, NULL);
419 0 : if (ret)
420 : return ret;
421 :
422 0 : switch (bo->resource->mem_type) {
423 : case TTM_PL_SYSTEM:
424 : fallthrough;
425 : case TTM_PL_TT:
426 0 : ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
427 0 : break;
428 : default:
429 0 : if (bo->bdev->funcs->access_memory)
430 0 : ret = bo->bdev->funcs->access_memory(
431 : bo, offset, buf, len, write);
432 : else
433 : ret = -EIO;
434 : }
435 :
436 0 : ttm_bo_unreserve(bo);
437 :
438 0 : return ret;
439 : }
440 : EXPORT_SYMBOL(ttm_bo_vm_access);
441 :
442 : static const struct vm_operations_struct ttm_bo_vm_ops = {
443 : .fault = ttm_bo_vm_fault,
444 : .open = ttm_bo_vm_open,
445 : .close = ttm_bo_vm_close,
446 : .access = ttm_bo_vm_access,
447 : };
448 :
449 0 : int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
450 : {
451 : /* Enforce no COW since would have really strange behavior with it. */
452 0 : if (is_cow_mapping(vma->vm_flags))
453 : return -EINVAL;
454 :
455 0 : ttm_bo_get(bo);
456 :
457 : /*
458 : * Drivers may want to override the vm_ops field. Otherwise we
459 : * use TTM's default callbacks.
460 : */
461 0 : if (!vma->vm_ops)
462 0 : vma->vm_ops = &ttm_bo_vm_ops;
463 :
464 : /*
465 : * Note: We're transferring the bo reference to
466 : * vma->vm_private_data here.
467 : */
468 :
469 0 : vma->vm_private_data = bo;
470 :
471 0 : vma->vm_flags |= VM_PFNMAP;
472 0 : vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
473 0 : return 0;
474 : }
475 : EXPORT_SYMBOL(ttm_bo_mmap_obj);
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