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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.h>
35#include <drm/ttm/ttm_placement.h>
36#include <drm/ttm/ttm_tt.h>
37
38#include <drm/drm_drv.h>
39#include <drm/drm_managed.h>
40
41static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
42 struct vm_fault *vmf)
43{
44 long err = 0;
45
46 /*
47 * Quick non-stalling check for idle.
48 */
49 if (dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_KERNEL))
50 return 0;
51
52 /*
53 * If possible, avoid waiting for GPU with mmap_lock
54 * held. We only do this if the fault allows retry and this
55 * is the first attempt.
56 */
57 if (fault_flag_allow_retry_first(vmf->flags)) {
58 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
59 return VM_FAULT_RETRY;
60
61 ttm_bo_get(bo);
62 mmap_read_unlock(vmf->vma->vm_mm);
63 (void)dma_resv_wait_timeout(bo->base.resv,
64 DMA_RESV_USAGE_KERNEL, true,
65 MAX_SCHEDULE_TIMEOUT);
66 dma_resv_unlock(bo->base.resv);
67 ttm_bo_put(bo);
68 return VM_FAULT_RETRY;
69 }
70
71 /*
72 * Ordinary wait.
73 */
74 err = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_KERNEL, true,
75 MAX_SCHEDULE_TIMEOUT);
76 if (unlikely(err < 0)) {
77 return (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
78 VM_FAULT_NOPAGE;
79 }
80
81 return 0;
82}
83
84static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
85 unsigned long page_offset)
86{
87 struct ttm_device *bdev = bo->bdev;
88
89 if (bdev->funcs->io_mem_pfn)
90 return bdev->funcs->io_mem_pfn(bo, page_offset);
91
92 return (bo->resource->bus.offset >> PAGE_SHIFT) + page_offset;
93}
94
95/**
96 * ttm_bo_vm_reserve - Reserve a buffer object in a retryable vm callback
97 * @bo: The buffer object
98 * @vmf: The fault structure handed to the callback
99 *
100 * vm callbacks like fault() and *_mkwrite() allow for the mmap_lock to be dropped
101 * during long waits, and after the wait the callback will be restarted. This
102 * is to allow other threads using the same virtual memory space concurrent
103 * access to map(), unmap() completely unrelated buffer objects. TTM buffer
104 * object reservations sometimes wait for GPU and should therefore be
105 * considered long waits. This function reserves the buffer object interruptibly
106 * taking this into account. Starvation is avoided by the vm system not
107 * allowing too many repeated restarts.
108 * This function is intended to be used in customized fault() and _mkwrite()
109 * handlers.
110 *
111 * Return:
112 * 0 on success and the bo was reserved.
113 * VM_FAULT_RETRY if blocking wait.
114 * VM_FAULT_NOPAGE if blocking wait and retrying was not allowed.
115 */
116vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
117 struct vm_fault *vmf)
118{
119 /*
120 * Work around locking order reversal in fault / nopfn
121 * between mmap_lock and bo_reserve: Perform a trylock operation
122 * for reserve, and if it fails, retry the fault after waiting
123 * for the buffer to become unreserved.
124 */
125 if (unlikely(!dma_resv_trylock(bo->base.resv))) {
126 /*
127 * If the fault allows retry and this is the first
128 * fault attempt, we try to release the mmap_lock
129 * before waiting
130 */
131 if (fault_flag_allow_retry_first(vmf->flags)) {
132 if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
133 ttm_bo_get(bo);
134 mmap_read_unlock(vmf->vma->vm_mm);
135 if (!dma_resv_lock_interruptible(bo->base.resv,
136 NULL))
137 dma_resv_unlock(bo->base.resv);
138 ttm_bo_put(bo);
139 }
140
141 return VM_FAULT_RETRY;
142 }
143
144 if (dma_resv_lock_interruptible(bo->base.resv, NULL))
145 return VM_FAULT_NOPAGE;
146 }
147
148 /*
149 * Refuse to fault imported pages. This should be handled
150 * (if at all) by redirecting mmap to the exporter.
151 */
152 if (bo->ttm && (bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
153 if (!(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE)) {
154 dma_resv_unlock(bo->base.resv);
155 return VM_FAULT_SIGBUS;
156 }
157 }
158
159 return 0;
160}
161EXPORT_SYMBOL(ttm_bo_vm_reserve);
162
163/**
164 * ttm_bo_vm_fault_reserved - TTM fault helper
165 * @vmf: The struct vm_fault given as argument to the fault callback
166 * @prot: The page protection to be used for this memory area.
167 * @num_prefault: Maximum number of prefault pages. The caller may want to
168 * specify this based on madvice settings and the size of the GPU object
169 * backed by the memory.
170 *
171 * This function inserts one or more page table entries pointing to the
172 * memory backing the buffer object, and then returns a return code
173 * instructing the caller to retry the page access.
174 *
175 * Return:
176 * VM_FAULT_NOPAGE on success or pending signal
177 * VM_FAULT_SIGBUS on unspecified error
178 * VM_FAULT_OOM on out-of-memory
179 * VM_FAULT_RETRY if retryable wait
180 */
181vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
182 pgprot_t prot,
183 pgoff_t num_prefault)
184{
185 struct vm_area_struct *vma = vmf->vma;
186 struct ttm_buffer_object *bo = vma->vm_private_data;
187 struct ttm_device *bdev = bo->bdev;
188 unsigned long page_offset;
189 unsigned long page_last;
190 unsigned long pfn;
191 struct ttm_tt *ttm = NULL;
192 struct page *page;
193 int err;
194 pgoff_t i;
195 vm_fault_t ret = VM_FAULT_NOPAGE;
196 unsigned long address = vmf->address;
197
198 /*
199 * Wait for buffer data in transit, due to a pipelined
200 * move.
201 */
202 ret = ttm_bo_vm_fault_idle(bo, vmf);
203 if (unlikely(ret != 0))
204 return ret;
205
206 err = ttm_mem_io_reserve(bdev, bo->resource);
207 if (unlikely(err != 0))
208 return VM_FAULT_SIGBUS;
209
210 page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
211 vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node);
212 page_last = vma_pages(vma) + vma->vm_pgoff -
213 drm_vma_node_start(&bo->base.vma_node);
214
215 if (unlikely(page_offset >= PFN_UP(bo->base.size)))
216 return VM_FAULT_SIGBUS;
217
218 prot = ttm_io_prot(bo, bo->resource, prot);
219 if (!bo->resource->bus.is_iomem) {
220 struct ttm_operation_ctx ctx = {
221 .interruptible = true,
222 .no_wait_gpu = false,
223 .force_alloc = true
224 };
225
226 ttm = bo->ttm;
227 err = ttm_bo_populate(bo, &ctx);
228 if (err) {
229 if (err == -EINTR || err == -ERESTARTSYS ||
230 err == -EAGAIN)
231 return VM_FAULT_NOPAGE;
232
233 pr_debug("TTM fault hit %pe.\n", ERR_PTR(err));
234 return VM_FAULT_SIGBUS;
235 }
236 } else {
237 /* Iomem should not be marked encrypted */
238 prot = pgprot_decrypted(prot);
239 }
240
241 /*
242 * Speculatively prefault a number of pages. Only error on
243 * first page.
244 */
245 for (i = 0; i < num_prefault; ++i) {
246 if (bo->resource->bus.is_iomem) {
247 pfn = ttm_bo_io_mem_pfn(bo, page_offset);
248 } else {
249 page = ttm->pages[page_offset];
250 if (unlikely(!page && i == 0)) {
251 return VM_FAULT_OOM;
252 } else if (unlikely(!page)) {
253 break;
254 }
255 pfn = page_to_pfn(page);
256 }
257
258 /*
259 * Note that the value of @prot at this point may differ from
260 * the value of @vma->vm_page_prot in the caching- and
261 * encryption bits. This is because the exact location of the
262 * data may not be known at mmap() time and may also change
263 * at arbitrary times while the data is mmap'ed.
264 * See vmf_insert_pfn_prot() for a discussion.
265 */
266 ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
267
268 /* Never error on prefaulted PTEs */
269 if (unlikely((ret & VM_FAULT_ERROR))) {
270 if (i == 0)
271 return VM_FAULT_NOPAGE;
272 else
273 break;
274 }
275
276 address += PAGE_SIZE;
277 if (unlikely(++page_offset >= page_last))
278 break;
279 }
280 return ret;
281}
282EXPORT_SYMBOL(ttm_bo_vm_fault_reserved);
283
284static void ttm_bo_release_dummy_page(struct drm_device *dev, void *res)
285{
286 struct page *dummy_page = (struct page *)res;
287
288 __free_page(dummy_page);
289}
290
291vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot)
292{
293 struct vm_area_struct *vma = vmf->vma;
294 struct ttm_buffer_object *bo = vma->vm_private_data;
295 struct drm_device *ddev = bo->base.dev;
296 vm_fault_t ret = VM_FAULT_NOPAGE;
297 unsigned long address;
298 unsigned long pfn;
299 struct page *page;
300
301 /* Allocate new dummy page to map all the VA range in this VMA to it*/
302 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
303 if (!page)
304 return VM_FAULT_OOM;
305
306 /* Set the page to be freed using drmm release action */
307 if (drmm_add_action_or_reset(ddev, ttm_bo_release_dummy_page, page))
308 return VM_FAULT_OOM;
309
310 pfn = page_to_pfn(page);
311
312 /* Prefault the entire VMA range right away to avoid further faults */
313 for (address = vma->vm_start; address < vma->vm_end;
314 address += PAGE_SIZE)
315 ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
316
317 return ret;
318}
319EXPORT_SYMBOL(ttm_bo_vm_dummy_page);
320
321vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
322{
323 struct vm_area_struct *vma = vmf->vma;
324 pgprot_t prot;
325 struct ttm_buffer_object *bo = vma->vm_private_data;
326 struct drm_device *ddev = bo->base.dev;
327 vm_fault_t ret;
328 int idx;
329
330 ret = ttm_bo_vm_reserve(bo, vmf);
331 if (ret)
332 return ret;
333
334 prot = vma->vm_page_prot;
335 if (drm_dev_enter(ddev, &idx)) {
336 ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT);
337 drm_dev_exit(idx);
338 } else {
339 ret = ttm_bo_vm_dummy_page(vmf, prot);
340 }
341 if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
342 return ret;
343
344 dma_resv_unlock(bo->base.resv);
345
346 return ret;
347}
348EXPORT_SYMBOL(ttm_bo_vm_fault);
349
350void ttm_bo_vm_open(struct vm_area_struct *vma)
351{
352 struct ttm_buffer_object *bo = vma->vm_private_data;
353
354 WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
355
356 ttm_bo_get(bo);
357}
358EXPORT_SYMBOL(ttm_bo_vm_open);
359
360void ttm_bo_vm_close(struct vm_area_struct *vma)
361{
362 struct ttm_buffer_object *bo = vma->vm_private_data;
363
364 ttm_bo_put(bo);
365 vma->vm_private_data = NULL;
366}
367EXPORT_SYMBOL(ttm_bo_vm_close);
368
369static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
370 unsigned long offset,
371 uint8_t *buf, int len, int write)
372{
373 unsigned long page = offset >> PAGE_SHIFT;
374 unsigned long bytes_left = len;
375 int ret;
376
377 /* Copy a page at a time, that way no extra virtual address
378 * mapping is needed
379 */
380 offset -= page << PAGE_SHIFT;
381 do {
382 unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
383 struct ttm_bo_kmap_obj map;
384 void *ptr;
385 bool is_iomem;
386
387 ret = ttm_bo_kmap(bo, page, 1, &map);
388 if (ret)
389 return ret;
390
391 ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
392 WARN_ON_ONCE(is_iomem);
393 if (write)
394 memcpy(ptr, buf, bytes);
395 else
396 memcpy(buf, ptr, bytes);
397 ttm_bo_kunmap(&map);
398
399 page++;
400 buf += bytes;
401 bytes_left -= bytes;
402 offset = 0;
403 } while (bytes_left);
404
405 return len;
406}
407
408int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
409 void *buf, int len, int write)
410{
411 struct ttm_buffer_object *bo = vma->vm_private_data;
412 unsigned long offset = (addr) - vma->vm_start +
413 ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))
414 << PAGE_SHIFT);
415 int ret;
416
417 if (len < 1 || (offset + len) > bo->base.size)
418 return -EIO;
419
420 ret = ttm_bo_reserve(bo, true, false, NULL);
421 if (ret)
422 return ret;
423
424 switch (bo->resource->mem_type) {
425 case TTM_PL_SYSTEM:
426 fallthrough;
427 case TTM_PL_TT:
428 ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
429 break;
430 default:
431 if (bo->bdev->funcs->access_memory)
432 ret = bo->bdev->funcs->access_memory(
433 bo, offset, buf, len, write);
434 else
435 ret = -EIO;
436 }
437
438 ttm_bo_unreserve(bo);
439
440 return ret;
441}
442EXPORT_SYMBOL(ttm_bo_vm_access);
443
444static const struct vm_operations_struct ttm_bo_vm_ops = {
445 .fault = ttm_bo_vm_fault,
446 .open = ttm_bo_vm_open,
447 .close = ttm_bo_vm_close,
448 .access = ttm_bo_vm_access,
449};
450
451/**
452 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
453 *
454 * @vma: vma as input from the fbdev mmap method.
455 * @bo: The bo backing the address space.
456 *
457 * Maps a buffer object.
458 */
459int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
460{
461 /* Enforce no COW since would have really strange behavior with it. */
462 if (is_cow_mapping(vma->vm_flags))
463 return -EINVAL;
464
465 ttm_bo_get(bo);
466
467 /*
468 * Drivers may want to override the vm_ops field. Otherwise we
469 * use TTM's default callbacks.
470 */
471 if (!vma->vm_ops)
472 vma->vm_ops = &ttm_bo_vm_ops;
473
474 /*
475 * Note: We're transferring the bo reference to
476 * vma->vm_private_data here.
477 */
478
479 vma->vm_private_data = bo;
480
481 vm_flags_set(vma, VM_PFNMAP | VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
482 return 0;
483}
484EXPORT_SYMBOL(ttm_bo_mmap_obj);
1/**************************************************************************
2 *
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
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 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29 */
30
31#define pr_fmt(fmt) "[TTM] " fmt
32
33#include <drm/ttm/ttm_module.h>
34#include <drm/ttm/ttm_bo_driver.h>
35#include <drm/ttm/ttm_placement.h>
36#include <drm/drm_vma_manager.h>
37#include <linux/mm.h>
38#include <linux/pfn_t.h>
39#include <linux/rbtree.h>
40#include <linux/module.h>
41#include <linux/uaccess.h>
42#include <linux/mem_encrypt.h>
43
44#define TTM_BO_VM_NUM_PREFAULT 16
45
46static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
47 struct vm_fault *vmf)
48{
49 int ret = 0;
50
51 if (likely(!bo->moving))
52 goto out_unlock;
53
54 /*
55 * Quick non-stalling check for idle.
56 */
57 if (dma_fence_is_signaled(bo->moving))
58 goto out_clear;
59
60 /*
61 * If possible, avoid waiting for GPU with mmap_sem
62 * held.
63 */
64 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
65 ret = VM_FAULT_RETRY;
66 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
67 goto out_unlock;
68
69 ttm_bo_reference(bo);
70 up_read(&vmf->vma->vm_mm->mmap_sem);
71 (void) dma_fence_wait(bo->moving, true);
72 ttm_bo_unreserve(bo);
73 ttm_bo_unref(&bo);
74 goto out_unlock;
75 }
76
77 /*
78 * Ordinary wait.
79 */
80 ret = dma_fence_wait(bo->moving, true);
81 if (unlikely(ret != 0)) {
82 ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
83 VM_FAULT_NOPAGE;
84 goto out_unlock;
85 }
86
87out_clear:
88 dma_fence_put(bo->moving);
89 bo->moving = NULL;
90
91out_unlock:
92 return ret;
93}
94
95static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
96 unsigned long page_offset)
97{
98 struct ttm_bo_device *bdev = bo->bdev;
99
100 if (bdev->driver->io_mem_pfn)
101 return bdev->driver->io_mem_pfn(bo, page_offset);
102
103 return ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT)
104 + page_offset;
105}
106
107static int ttm_bo_vm_fault(struct vm_fault *vmf)
108{
109 struct vm_area_struct *vma = vmf->vma;
110 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
111 vma->vm_private_data;
112 struct ttm_bo_device *bdev = bo->bdev;
113 unsigned long page_offset;
114 unsigned long page_last;
115 unsigned long pfn;
116 struct ttm_tt *ttm = NULL;
117 struct page *page;
118 int ret;
119 int i;
120 unsigned long address = vmf->address;
121 struct ttm_mem_type_manager *man =
122 &bdev->man[bo->mem.mem_type];
123 struct vm_area_struct cvma;
124
125 /*
126 * Work around locking order reversal in fault / nopfn
127 * between mmap_sem and bo_reserve: Perform a trylock operation
128 * for reserve, and if it fails, retry the fault after waiting
129 * for the buffer to become unreserved.
130 */
131 ret = ttm_bo_reserve(bo, true, true, NULL);
132 if (unlikely(ret != 0)) {
133 if (ret != -EBUSY)
134 return VM_FAULT_NOPAGE;
135
136 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
137 if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
138 ttm_bo_reference(bo);
139 up_read(&vmf->vma->vm_mm->mmap_sem);
140 (void) ttm_bo_wait_unreserved(bo);
141 ttm_bo_unref(&bo);
142 }
143
144 return VM_FAULT_RETRY;
145 }
146
147 /*
148 * If we'd want to change locking order to
149 * mmap_sem -> bo::reserve, we'd use a blocking reserve here
150 * instead of retrying the fault...
151 */
152 return VM_FAULT_NOPAGE;
153 }
154
155 /*
156 * Refuse to fault imported pages. This should be handled
157 * (if at all) by redirecting mmap to the exporter.
158 */
159 if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
160 ret = VM_FAULT_SIGBUS;
161 goto out_unlock;
162 }
163
164 if (bdev->driver->fault_reserve_notify) {
165 ret = bdev->driver->fault_reserve_notify(bo);
166 switch (ret) {
167 case 0:
168 break;
169 case -EBUSY:
170 case -ERESTARTSYS:
171 ret = VM_FAULT_NOPAGE;
172 goto out_unlock;
173 default:
174 ret = VM_FAULT_SIGBUS;
175 goto out_unlock;
176 }
177 }
178
179 /*
180 * Wait for buffer data in transit, due to a pipelined
181 * move.
182 */
183 ret = ttm_bo_vm_fault_idle(bo, vmf);
184 if (unlikely(ret != 0)) {
185 if (ret == VM_FAULT_RETRY &&
186 !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
187 /* The BO has already been unreserved. */
188 return ret;
189 }
190
191 goto out_unlock;
192 }
193
194 ret = ttm_mem_io_lock(man, true);
195 if (unlikely(ret != 0)) {
196 ret = VM_FAULT_NOPAGE;
197 goto out_unlock;
198 }
199 ret = ttm_mem_io_reserve_vm(bo);
200 if (unlikely(ret != 0)) {
201 ret = VM_FAULT_SIGBUS;
202 goto out_io_unlock;
203 }
204
205 page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
206 vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
207 page_last = vma_pages(vma) + vma->vm_pgoff -
208 drm_vma_node_start(&bo->vma_node);
209
210 if (unlikely(page_offset >= bo->num_pages)) {
211 ret = VM_FAULT_SIGBUS;
212 goto out_io_unlock;
213 }
214
215 /*
216 * Make a local vma copy to modify the page_prot member
217 * and vm_flags if necessary. The vma parameter is protected
218 * by mmap_sem in write mode.
219 */
220 cvma = *vma;
221 cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);
222
223 if (bo->mem.bus.is_iomem) {
224 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
225 cvma.vm_page_prot);
226 } else {
227 struct ttm_operation_ctx ctx = {
228 .interruptible = false,
229 .no_wait_gpu = false,
230 .flags = TTM_OPT_FLAG_FORCE_ALLOC
231
232 };
233
234 ttm = bo->ttm;
235 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
236 cvma.vm_page_prot);
237
238 /* Allocate all page at once, most common usage */
239 if (ttm_tt_populate(ttm, &ctx)) {
240 ret = VM_FAULT_OOM;
241 goto out_io_unlock;
242 }
243 }
244
245 /*
246 * Speculatively prefault a number of pages. Only error on
247 * first page.
248 */
249 for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
250 if (bo->mem.bus.is_iomem) {
251 /* Iomem should not be marked encrypted */
252 cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot);
253 pfn = ttm_bo_io_mem_pfn(bo, page_offset);
254 } else {
255 page = ttm->pages[page_offset];
256 if (unlikely(!page && i == 0)) {
257 ret = VM_FAULT_OOM;
258 goto out_io_unlock;
259 } else if (unlikely(!page)) {
260 break;
261 }
262 page->index = drm_vma_node_start(&bo->vma_node) +
263 page_offset;
264 pfn = page_to_pfn(page);
265 }
266
267 if (vma->vm_flags & VM_MIXEDMAP)
268 ret = vm_insert_mixed(&cvma, address,
269 __pfn_to_pfn_t(pfn, PFN_DEV));
270 else
271 ret = vm_insert_pfn(&cvma, address, pfn);
272
273 /*
274 * Somebody beat us to this PTE or prefaulting to
275 * an already populated PTE, or prefaulting error.
276 */
277
278 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
279 break;
280 else if (unlikely(ret != 0)) {
281 ret =
282 (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
283 goto out_io_unlock;
284 }
285
286 address += PAGE_SIZE;
287 if (unlikely(++page_offset >= page_last))
288 break;
289 }
290 ret = VM_FAULT_NOPAGE;
291out_io_unlock:
292 ttm_mem_io_unlock(man);
293out_unlock:
294 ttm_bo_unreserve(bo);
295 return ret;
296}
297
298static void ttm_bo_vm_open(struct vm_area_struct *vma)
299{
300 struct ttm_buffer_object *bo =
301 (struct ttm_buffer_object *)vma->vm_private_data;
302
303 WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
304
305 (void)ttm_bo_reference(bo);
306}
307
308static void ttm_bo_vm_close(struct vm_area_struct *vma)
309{
310 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
311
312 ttm_bo_unref(&bo);
313 vma->vm_private_data = NULL;
314}
315
316static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
317 unsigned long offset,
318 uint8_t *buf, int len, int write)
319{
320 unsigned long page = offset >> PAGE_SHIFT;
321 unsigned long bytes_left = len;
322 int ret;
323
324 /* Copy a page at a time, that way no extra virtual address
325 * mapping is needed
326 */
327 offset -= page << PAGE_SHIFT;
328 do {
329 unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
330 struct ttm_bo_kmap_obj map;
331 void *ptr;
332 bool is_iomem;
333
334 ret = ttm_bo_kmap(bo, page, 1, &map);
335 if (ret)
336 return ret;
337
338 ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
339 WARN_ON_ONCE(is_iomem);
340 if (write)
341 memcpy(ptr, buf, bytes);
342 else
343 memcpy(buf, ptr, bytes);
344 ttm_bo_kunmap(&map);
345
346 page++;
347 buf += bytes;
348 bytes_left -= bytes;
349 offset = 0;
350 } while (bytes_left);
351
352 return len;
353}
354
355static int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
356 void *buf, int len, int write)
357{
358 unsigned long offset = (addr) - vma->vm_start;
359 struct ttm_buffer_object *bo = vma->vm_private_data;
360 int ret;
361
362 if (len < 1 || (offset + len) >> PAGE_SHIFT > bo->num_pages)
363 return -EIO;
364
365 ret = ttm_bo_reserve(bo, true, false, NULL);
366 if (ret)
367 return ret;
368
369 switch (bo->mem.mem_type) {
370 case TTM_PL_SYSTEM:
371 if (unlikely(bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
372 ret = ttm_tt_swapin(bo->ttm);
373 if (unlikely(ret != 0))
374 return ret;
375 }
376 /* fall through */
377 case TTM_PL_TT:
378 ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
379 break;
380 default:
381 if (bo->bdev->driver->access_memory)
382 ret = bo->bdev->driver->access_memory(
383 bo, offset, buf, len, write);
384 else
385 ret = -EIO;
386 }
387
388 ttm_bo_unreserve(bo);
389
390 return ret;
391}
392
393static const struct vm_operations_struct ttm_bo_vm_ops = {
394 .fault = ttm_bo_vm_fault,
395 .open = ttm_bo_vm_open,
396 .close = ttm_bo_vm_close,
397 .access = ttm_bo_vm_access
398};
399
400static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
401 unsigned long offset,
402 unsigned long pages)
403{
404 struct drm_vma_offset_node *node;
405 struct ttm_buffer_object *bo = NULL;
406
407 drm_vma_offset_lock_lookup(&bdev->vma_manager);
408
409 node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
410 if (likely(node)) {
411 bo = container_of(node, struct ttm_buffer_object, vma_node);
412 if (!kref_get_unless_zero(&bo->kref))
413 bo = NULL;
414 }
415
416 drm_vma_offset_unlock_lookup(&bdev->vma_manager);
417
418 if (!bo)
419 pr_err("Could not find buffer object to map\n");
420
421 return bo;
422}
423
424int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
425 struct ttm_bo_device *bdev)
426{
427 struct ttm_bo_driver *driver;
428 struct ttm_buffer_object *bo;
429 int ret;
430
431 bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
432 if (unlikely(!bo))
433 return -EINVAL;
434
435 driver = bo->bdev->driver;
436 if (unlikely(!driver->verify_access)) {
437 ret = -EPERM;
438 goto out_unref;
439 }
440 ret = driver->verify_access(bo, filp);
441 if (unlikely(ret != 0))
442 goto out_unref;
443
444 vma->vm_ops = &ttm_bo_vm_ops;
445
446 /*
447 * Note: We're transferring the bo reference to
448 * vma->vm_private_data here.
449 */
450
451 vma->vm_private_data = bo;
452
453 /*
454 * We'd like to use VM_PFNMAP on shared mappings, where
455 * (vma->vm_flags & VM_SHARED) != 0, for performance reasons,
456 * but for some reason VM_PFNMAP + x86 PAT + write-combine is very
457 * bad for performance. Until that has been sorted out, use
458 * VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
459 */
460 vma->vm_flags |= VM_MIXEDMAP;
461 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
462 return 0;
463out_unref:
464 ttm_bo_unref(&bo);
465 return ret;
466}
467EXPORT_SYMBOL(ttm_bo_mmap);
468
469int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
470{
471 if (vma->vm_pgoff != 0)
472 return -EACCES;
473
474 vma->vm_ops = &ttm_bo_vm_ops;
475 vma->vm_private_data = ttm_bo_reference(bo);
476 vma->vm_flags |= VM_MIXEDMAP;
477 vma->vm_flags |= VM_IO | VM_DONTEXPAND;
478 return 0;
479}
480EXPORT_SYMBOL(ttm_fbdev_mmap);