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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#include <ttm/ttm_module.h>
32#include <ttm/ttm_bo_driver.h>
33#include <ttm/ttm_placement.h>
34#include <linux/mm.h>
35#include <linux/rbtree.h>
36#include <linux/module.h>
37#include <linux/uaccess.h>
38
39#define TTM_BO_VM_NUM_PREFAULT 16
40
41static struct ttm_buffer_object *ttm_bo_vm_lookup_rb(struct ttm_bo_device *bdev,
42 unsigned long page_start,
43 unsigned long num_pages)
44{
45 struct rb_node *cur = bdev->addr_space_rb.rb_node;
46 unsigned long cur_offset;
47 struct ttm_buffer_object *bo;
48 struct ttm_buffer_object *best_bo = NULL;
49
50 while (likely(cur != NULL)) {
51 bo = rb_entry(cur, struct ttm_buffer_object, vm_rb);
52 cur_offset = bo->vm_node->start;
53 if (page_start >= cur_offset) {
54 cur = cur->rb_right;
55 best_bo = bo;
56 if (page_start == cur_offset)
57 break;
58 } else
59 cur = cur->rb_left;
60 }
61
62 if (unlikely(best_bo == NULL))
63 return NULL;
64
65 if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
66 (page_start + num_pages)))
67 return NULL;
68
69 return best_bo;
70}
71
72static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
73{
74 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
75 vma->vm_private_data;
76 struct ttm_bo_device *bdev = bo->bdev;
77 unsigned long page_offset;
78 unsigned long page_last;
79 unsigned long pfn;
80 struct ttm_tt *ttm = NULL;
81 struct page *page;
82 int ret;
83 int i;
84 unsigned long address = (unsigned long)vmf->virtual_address;
85 int retval = VM_FAULT_NOPAGE;
86 struct ttm_mem_type_manager *man =
87 &bdev->man[bo->mem.mem_type];
88
89 /*
90 * Work around locking order reversal in fault / nopfn
91 * between mmap_sem and bo_reserve: Perform a trylock operation
92 * for reserve, and if it fails, retry the fault after scheduling.
93 */
94
95 ret = ttm_bo_reserve(bo, true, true, false, 0);
96 if (unlikely(ret != 0)) {
97 if (ret == -EBUSY)
98 set_need_resched();
99 return VM_FAULT_NOPAGE;
100 }
101
102 if (bdev->driver->fault_reserve_notify) {
103 ret = bdev->driver->fault_reserve_notify(bo);
104 switch (ret) {
105 case 0:
106 break;
107 case -EBUSY:
108 set_need_resched();
109 case -ERESTARTSYS:
110 retval = VM_FAULT_NOPAGE;
111 goto out_unlock;
112 default:
113 retval = VM_FAULT_SIGBUS;
114 goto out_unlock;
115 }
116 }
117
118 /*
119 * Wait for buffer data in transit, due to a pipelined
120 * move.
121 */
122
123 spin_lock(&bdev->fence_lock);
124 if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
125 ret = ttm_bo_wait(bo, false, true, false);
126 spin_unlock(&bdev->fence_lock);
127 if (unlikely(ret != 0)) {
128 retval = (ret != -ERESTARTSYS) ?
129 VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
130 goto out_unlock;
131 }
132 } else
133 spin_unlock(&bdev->fence_lock);
134
135 ret = ttm_mem_io_lock(man, true);
136 if (unlikely(ret != 0)) {
137 retval = VM_FAULT_NOPAGE;
138 goto out_unlock;
139 }
140 ret = ttm_mem_io_reserve_vm(bo);
141 if (unlikely(ret != 0)) {
142 retval = VM_FAULT_SIGBUS;
143 goto out_io_unlock;
144 }
145
146 page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
147 bo->vm_node->start - vma->vm_pgoff;
148 page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) +
149 bo->vm_node->start - vma->vm_pgoff;
150
151 if (unlikely(page_offset >= bo->num_pages)) {
152 retval = VM_FAULT_SIGBUS;
153 goto out_io_unlock;
154 }
155
156 /*
157 * Strictly, we're not allowed to modify vma->vm_page_prot here,
158 * since the mmap_sem is only held in read mode. However, we
159 * modify only the caching bits of vma->vm_page_prot and
160 * consider those bits protected by
161 * the bo->mutex, as we should be the only writers.
162 * There shouldn't really be any readers of these bits except
163 * within vm_insert_mixed()? fork?
164 *
165 * TODO: Add a list of vmas to the bo, and change the
166 * vma->vm_page_prot when the object changes caching policy, with
167 * the correct locks held.
168 */
169 if (bo->mem.bus.is_iomem) {
170 vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
171 vma->vm_page_prot);
172 } else {
173 ttm = bo->ttm;
174 vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
175 vm_get_page_prot(vma->vm_flags) :
176 ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
177 }
178
179 /*
180 * Speculatively prefault a number of pages. Only error on
181 * first page.
182 */
183
184 for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
185 if (bo->mem.bus.is_iomem)
186 pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
187 else {
188 page = ttm_tt_get_page(ttm, page_offset);
189 if (unlikely(!page && i == 0)) {
190 retval = VM_FAULT_OOM;
191 goto out_io_unlock;
192 } else if (unlikely(!page)) {
193 break;
194 }
195 pfn = page_to_pfn(page);
196 }
197
198 ret = vm_insert_mixed(vma, address, pfn);
199 /*
200 * Somebody beat us to this PTE or prefaulting to
201 * an already populated PTE, or prefaulting error.
202 */
203
204 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
205 break;
206 else if (unlikely(ret != 0)) {
207 retval =
208 (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
209 goto out_io_unlock;
210 }
211
212 address += PAGE_SIZE;
213 if (unlikely(++page_offset >= page_last))
214 break;
215 }
216out_io_unlock:
217 ttm_mem_io_unlock(man);
218out_unlock:
219 ttm_bo_unreserve(bo);
220 return retval;
221}
222
223static void ttm_bo_vm_open(struct vm_area_struct *vma)
224{
225 struct ttm_buffer_object *bo =
226 (struct ttm_buffer_object *)vma->vm_private_data;
227
228 (void)ttm_bo_reference(bo);
229}
230
231static void ttm_bo_vm_close(struct vm_area_struct *vma)
232{
233 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
234
235 ttm_bo_unref(&bo);
236 vma->vm_private_data = NULL;
237}
238
239static const struct vm_operations_struct ttm_bo_vm_ops = {
240 .fault = ttm_bo_vm_fault,
241 .open = ttm_bo_vm_open,
242 .close = ttm_bo_vm_close
243};
244
245int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
246 struct ttm_bo_device *bdev)
247{
248 struct ttm_bo_driver *driver;
249 struct ttm_buffer_object *bo;
250 int ret;
251
252 read_lock(&bdev->vm_lock);
253 bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
254 (vma->vm_end - vma->vm_start) >> PAGE_SHIFT);
255 if (likely(bo != NULL))
256 ttm_bo_reference(bo);
257 read_unlock(&bdev->vm_lock);
258
259 if (unlikely(bo == NULL)) {
260 printk(KERN_ERR TTM_PFX
261 "Could not find buffer object to map.\n");
262 return -EINVAL;
263 }
264
265 driver = bo->bdev->driver;
266 if (unlikely(!driver->verify_access)) {
267 ret = -EPERM;
268 goto out_unref;
269 }
270 ret = driver->verify_access(bo, filp);
271 if (unlikely(ret != 0))
272 goto out_unref;
273
274 vma->vm_ops = &ttm_bo_vm_ops;
275
276 /*
277 * Note: We're transferring the bo reference to
278 * vma->vm_private_data here.
279 */
280
281 vma->vm_private_data = bo;
282 vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
283 return 0;
284out_unref:
285 ttm_bo_unref(&bo);
286 return ret;
287}
288EXPORT_SYMBOL(ttm_bo_mmap);
289
290int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
291{
292 if (vma->vm_pgoff != 0)
293 return -EACCES;
294
295 vma->vm_ops = &ttm_bo_vm_ops;
296 vma->vm_private_data = ttm_bo_reference(bo);
297 vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
298 return 0;
299}
300EXPORT_SYMBOL(ttm_fbdev_mmap);
301
302
303ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
304 const char __user *wbuf, char __user *rbuf, size_t count,
305 loff_t *f_pos, bool write)
306{
307 struct ttm_buffer_object *bo;
308 struct ttm_bo_driver *driver;
309 struct ttm_bo_kmap_obj map;
310 unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
311 unsigned long kmap_offset;
312 unsigned long kmap_end;
313 unsigned long kmap_num;
314 size_t io_size;
315 unsigned int page_offset;
316 char *virtual;
317 int ret;
318 bool no_wait = false;
319 bool dummy;
320
321 read_lock(&bdev->vm_lock);
322 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
323 if (likely(bo != NULL))
324 ttm_bo_reference(bo);
325 read_unlock(&bdev->vm_lock);
326
327 if (unlikely(bo == NULL))
328 return -EFAULT;
329
330 driver = bo->bdev->driver;
331 if (unlikely(!driver->verify_access)) {
332 ret = -EPERM;
333 goto out_unref;
334 }
335
336 ret = driver->verify_access(bo, filp);
337 if (unlikely(ret != 0))
338 goto out_unref;
339
340 kmap_offset = dev_offset - bo->vm_node->start;
341 if (unlikely(kmap_offset >= bo->num_pages)) {
342 ret = -EFBIG;
343 goto out_unref;
344 }
345
346 page_offset = *f_pos & ~PAGE_MASK;
347 io_size = bo->num_pages - kmap_offset;
348 io_size = (io_size << PAGE_SHIFT) - page_offset;
349 if (count < io_size)
350 io_size = count;
351
352 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
353 kmap_num = kmap_end - kmap_offset + 1;
354
355 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
356
357 switch (ret) {
358 case 0:
359 break;
360 case -EBUSY:
361 ret = -EAGAIN;
362 goto out_unref;
363 default:
364 goto out_unref;
365 }
366
367 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
368 if (unlikely(ret != 0)) {
369 ttm_bo_unreserve(bo);
370 goto out_unref;
371 }
372
373 virtual = ttm_kmap_obj_virtual(&map, &dummy);
374 virtual += page_offset;
375
376 if (write)
377 ret = copy_from_user(virtual, wbuf, io_size);
378 else
379 ret = copy_to_user(rbuf, virtual, io_size);
380
381 ttm_bo_kunmap(&map);
382 ttm_bo_unreserve(bo);
383 ttm_bo_unref(&bo);
384
385 if (unlikely(ret != 0))
386 return -EFBIG;
387
388 *f_pos += io_size;
389
390 return io_size;
391out_unref:
392 ttm_bo_unref(&bo);
393 return ret;
394}
395
396ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
397 char __user *rbuf, size_t count, loff_t *f_pos,
398 bool write)
399{
400 struct ttm_bo_kmap_obj map;
401 unsigned long kmap_offset;
402 unsigned long kmap_end;
403 unsigned long kmap_num;
404 size_t io_size;
405 unsigned int page_offset;
406 char *virtual;
407 int ret;
408 bool no_wait = false;
409 bool dummy;
410
411 kmap_offset = (*f_pos >> PAGE_SHIFT);
412 if (unlikely(kmap_offset >= bo->num_pages))
413 return -EFBIG;
414
415 page_offset = *f_pos & ~PAGE_MASK;
416 io_size = bo->num_pages - kmap_offset;
417 io_size = (io_size << PAGE_SHIFT) - page_offset;
418 if (count < io_size)
419 io_size = count;
420
421 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
422 kmap_num = kmap_end - kmap_offset + 1;
423
424 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
425
426 switch (ret) {
427 case 0:
428 break;
429 case -EBUSY:
430 return -EAGAIN;
431 default:
432 return ret;
433 }
434
435 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
436 if (unlikely(ret != 0)) {
437 ttm_bo_unreserve(bo);
438 return ret;
439 }
440
441 virtual = ttm_kmap_obj_virtual(&map, &dummy);
442 virtual += page_offset;
443
444 if (write)
445 ret = copy_from_user(virtual, wbuf, io_size);
446 else
447 ret = copy_to_user(rbuf, virtual, io_size);
448
449 ttm_bo_kunmap(&map);
450 ttm_bo_unreserve(bo);
451 ttm_bo_unref(&bo);
452
453 if (unlikely(ret != 0))
454 return ret;
455
456 *f_pos += io_size;
457
458 return io_size;
459}
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_tt_populate(bdev, bo->ttm, &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);