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