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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_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
46static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
47 struct vm_fault *vmf)
48{
49 long err = 0;
50
51 /*
52 * Quick non-stalling check for idle.
53 */
54 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 if (fault_flag_allow_retry_first(vmf->flags)) {
63 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
64 return VM_FAULT_RETRY;
65
66 ttm_bo_get(bo);
67 mmap_read_unlock(vmf->vma->vm_mm);
68 (void)dma_resv_wait_timeout(bo->base.resv,
69 DMA_RESV_USAGE_KERNEL, true,
70 MAX_SCHEDULE_TIMEOUT);
71 dma_resv_unlock(bo->base.resv);
72 ttm_bo_put(bo);
73 return VM_FAULT_RETRY;
74 }
75
76 /*
77 * Ordinary wait.
78 */
79 err = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_KERNEL, true,
80 MAX_SCHEDULE_TIMEOUT);
81 if (unlikely(err < 0)) {
82 return (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
83 VM_FAULT_NOPAGE;
84 }
85
86 return 0;
87}
88
89static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
90 unsigned long page_offset)
91{
92 struct ttm_device *bdev = bo->bdev;
93
94 if (bdev->funcs->io_mem_pfn)
95 return bdev->funcs->io_mem_pfn(bo, page_offset);
96
97 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 mmap_lock 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 */
121vm_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 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 if (fault_flag_allow_retry_first(vmf->flags)) {
137 if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
138 ttm_bo_get(bo);
139 mmap_read_unlock(vmf->vma->vm_mm);
140 if (!dma_resv_lock_interruptible(bo->base.resv,
141 NULL))
142 dma_resv_unlock(bo->base.resv);
143 ttm_bo_put(bo);
144 }
145
146 return VM_FAULT_RETRY;
147 }
148
149 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 if (bo->ttm && (bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
158 if (!(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE)) {
159 dma_resv_unlock(bo->base.resv);
160 return VM_FAULT_SIGBUS;
161 }
162 }
163
164 return 0;
165}
166EXPORT_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 */
186vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
187 pgprot_t prot,
188 pgoff_t num_prefault)
189{
190 struct vm_area_struct *vma = vmf->vma;
191 struct ttm_buffer_object *bo = vma->vm_private_data;
192 struct ttm_device *bdev = bo->bdev;
193 unsigned long page_offset;
194 unsigned long page_last;
195 unsigned long pfn;
196 struct ttm_tt *ttm = NULL;
197 struct page *page;
198 int err;
199 pgoff_t i;
200 vm_fault_t ret = VM_FAULT_NOPAGE;
201 unsigned long address = vmf->address;
202
203 /*
204 * Wait for buffer data in transit, due to a pipelined
205 * move.
206 */
207 ret = ttm_bo_vm_fault_idle(bo, vmf);
208 if (unlikely(ret != 0))
209 return ret;
210
211 err = ttm_mem_io_reserve(bdev, bo->resource);
212 if (unlikely(err != 0))
213 return VM_FAULT_SIGBUS;
214
215 page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
216 vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node);
217 page_last = vma_pages(vma) + vma->vm_pgoff -
218 drm_vma_node_start(&bo->base.vma_node);
219
220 if (unlikely(page_offset >= PFN_UP(bo->base.size)))
221 return VM_FAULT_SIGBUS;
222
223 prot = ttm_io_prot(bo, bo->resource, prot);
224 if (!bo->resource->bus.is_iomem) {
225 struct ttm_operation_ctx ctx = {
226 .interruptible = false,
227 .no_wait_gpu = false,
228 .force_alloc = true
229 };
230
231 ttm = bo->ttm;
232 if (ttm_tt_populate(bdev, bo->ttm, &ctx))
233 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 for (i = 0; i < num_prefault; ++i) {
244 if (bo->resource->bus.is_iomem) {
245 pfn = ttm_bo_io_mem_pfn(bo, page_offset);
246 } else {
247 page = ttm->pages[page_offset];
248 if (unlikely(!page && i == 0)) {
249 return VM_FAULT_OOM;
250 } else if (unlikely(!page)) {
251 break;
252 }
253 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 ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
265
266 /* Never error on prefaulted PTEs */
267 if (unlikely((ret & VM_FAULT_ERROR))) {
268 if (i == 0)
269 return VM_FAULT_NOPAGE;
270 else
271 break;
272 }
273
274 address += PAGE_SIZE;
275 if (unlikely(++page_offset >= page_last))
276 break;
277 }
278 return ret;
279}
280EXPORT_SYMBOL(ttm_bo_vm_fault_reserved);
281
282static void ttm_bo_release_dummy_page(struct drm_device *dev, void *res)
283{
284 struct page *dummy_page = (struct page *)res;
285
286 __free_page(dummy_page);
287}
288
289vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot)
290{
291 struct vm_area_struct *vma = vmf->vma;
292 struct ttm_buffer_object *bo = vma->vm_private_data;
293 struct drm_device *ddev = bo->base.dev;
294 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 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
301 if (!page)
302 return VM_FAULT_OOM;
303
304 /* Set the page to be freed using drmm release action */
305 if (drmm_add_action_or_reset(ddev, ttm_bo_release_dummy_page, page))
306 return VM_FAULT_OOM;
307
308 pfn = page_to_pfn(page);
309
310 /* Prefault the entire VMA range right away to avoid further faults */
311 for (address = vma->vm_start; address < vma->vm_end;
312 address += PAGE_SIZE)
313 ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
314
315 return ret;
316}
317EXPORT_SYMBOL(ttm_bo_vm_dummy_page);
318
319vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
320{
321 struct vm_area_struct *vma = vmf->vma;
322 pgprot_t prot;
323 struct ttm_buffer_object *bo = vma->vm_private_data;
324 struct drm_device *ddev = bo->base.dev;
325 vm_fault_t ret;
326 int idx;
327
328 ret = ttm_bo_vm_reserve(bo, vmf);
329 if (ret)
330 return ret;
331
332 prot = vma->vm_page_prot;
333 if (drm_dev_enter(ddev, &idx)) {
334 ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT);
335 drm_dev_exit(idx);
336 } else {
337 ret = ttm_bo_vm_dummy_page(vmf, prot);
338 }
339 if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
340 return ret;
341
342 dma_resv_unlock(bo->base.resv);
343
344 return ret;
345}
346EXPORT_SYMBOL(ttm_bo_vm_fault);
347
348void ttm_bo_vm_open(struct vm_area_struct *vma)
349{
350 struct ttm_buffer_object *bo = vma->vm_private_data;
351
352 WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
353
354 ttm_bo_get(bo);
355}
356EXPORT_SYMBOL(ttm_bo_vm_open);
357
358void ttm_bo_vm_close(struct vm_area_struct *vma)
359{
360 struct ttm_buffer_object *bo = vma->vm_private_data;
361
362 ttm_bo_put(bo);
363 vma->vm_private_data = NULL;
364}
365EXPORT_SYMBOL(ttm_bo_vm_close);
366
367static 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 unsigned long page = offset >> PAGE_SHIFT;
372 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 offset -= page << PAGE_SHIFT;
379 do {
380 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 ret = ttm_bo_kmap(bo, page, 1, &map);
386 if (ret)
387 return ret;
388
389 ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
390 WARN_ON_ONCE(is_iomem);
391 if (write)
392 memcpy(ptr, buf, bytes);
393 else
394 memcpy(buf, ptr, bytes);
395 ttm_bo_kunmap(&map);
396
397 page++;
398 buf += bytes;
399 bytes_left -= bytes;
400 offset = 0;
401 } while (bytes_left);
402
403 return len;
404}
405
406int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
407 void *buf, int len, int write)
408{
409 struct ttm_buffer_object *bo = vma->vm_private_data;
410 unsigned long offset = (addr) - vma->vm_start +
411 ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))
412 << PAGE_SHIFT);
413 int ret;
414
415 if (len < 1 || (offset + len) > bo->base.size)
416 return -EIO;
417
418 ret = ttm_bo_reserve(bo, true, false, NULL);
419 if (ret)
420 return ret;
421
422 switch (bo->resource->mem_type) {
423 case TTM_PL_SYSTEM:
424 fallthrough;
425 case TTM_PL_TT:
426 ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
427 break;
428 default:
429 if (bo->bdev->funcs->access_memory)
430 ret = bo->bdev->funcs->access_memory(
431 bo, offset, buf, len, write);
432 else
433 ret = -EIO;
434 }
435
436 ttm_bo_unreserve(bo);
437
438 return ret;
439}
440EXPORT_SYMBOL(ttm_bo_vm_access);
441
442static 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
449int 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 if (is_cow_mapping(vma->vm_flags))
453 return -EINVAL;
454
455 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 if (!vma->vm_ops)
462 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 vma->vm_private_data = bo;
470
471 vma->vm_flags |= VM_PFNMAP;
472 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
473 return 0;
474}
475EXPORT_SYMBOL(ttm_bo_mmap_obj);