blob: 40b75032ea47459a43b5de71d8801c84e201180b [file] [log] [blame]
Thomas Hellstromba4e7d92009-06-10 15:20:19 +02001/**************************************************************************
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>
Thomas Hellstromba4e7d92009-06-10 15:20:19 +020035#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 bus_base;
78 unsigned long bus_offset;
79 unsigned long bus_size;
80 unsigned long page_offset;
81 unsigned long page_last;
82 unsigned long pfn;
83 struct ttm_tt *ttm = NULL;
84 struct page *page;
85 int ret;
86 int i;
87 bool is_iomem;
88 unsigned long address = (unsigned long)vmf->virtual_address;
89 int retval = VM_FAULT_NOPAGE;
90
91 /*
92 * Work around locking order reversal in fault / nopfn
93 * between mmap_sem and bo_reserve: Perform a trylock operation
94 * for reserve, and if it fails, retry the fault after scheduling.
95 */
96
97 ret = ttm_bo_reserve(bo, true, true, false, 0);
98 if (unlikely(ret != 0)) {
99 if (ret == -EBUSY)
100 set_need_resched();
101 return VM_FAULT_NOPAGE;
102 }
103
104 /*
105 * Wait for buffer data in transit, due to a pipelined
106 * move.
107 */
108
109 spin_lock(&bo->lock);
110 if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
111 ret = ttm_bo_wait(bo, false, true, false);
112 spin_unlock(&bo->lock);
113 if (unlikely(ret != 0)) {
114 retval = (ret != -ERESTART) ?
115 VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;
116 goto out_unlock;
117 }
118 } else
119 spin_unlock(&bo->lock);
120
121
122 ret = ttm_bo_pci_offset(bdev, &bo->mem, &bus_base, &bus_offset,
123 &bus_size);
124 if (unlikely(ret != 0)) {
125 retval = VM_FAULT_SIGBUS;
126 goto out_unlock;
127 }
128
129 is_iomem = (bus_size != 0);
130
131 page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
132 bo->vm_node->start - vma->vm_pgoff;
133 page_last = ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) +
134 bo->vm_node->start - vma->vm_pgoff;
135
136 if (unlikely(page_offset >= bo->num_pages)) {
137 retval = VM_FAULT_SIGBUS;
138 goto out_unlock;
139 }
140
141 /*
142 * Strictly, we're not allowed to modify vma->vm_page_prot here,
143 * since the mmap_sem is only held in read mode. However, we
144 * modify only the caching bits of vma->vm_page_prot and
145 * consider those bits protected by
146 * the bo->mutex, as we should be the only writers.
147 * There shouldn't really be any readers of these bits except
148 * within vm_insert_mixed()? fork?
149 *
150 * TODO: Add a list of vmas to the bo, and change the
151 * vma->vm_page_prot when the object changes caching policy, with
152 * the correct locks held.
153 */
154
155 if (is_iomem) {
156 vma->vm_page_prot = ttm_io_prot(bo->mem.placement,
157 vma->vm_page_prot);
158 } else {
159 ttm = bo->ttm;
160 vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
161 vm_get_page_prot(vma->vm_flags) :
162 ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
163 }
164
165 /*
166 * Speculatively prefault a number of pages. Only error on
167 * first page.
168 */
169
170 for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
171
172 if (is_iomem)
173 pfn = ((bus_base + bus_offset) >> PAGE_SHIFT) +
174 page_offset;
175 else {
176 page = ttm_tt_get_page(ttm, page_offset);
177 if (unlikely(!page && i == 0)) {
178 retval = VM_FAULT_OOM;
179 goto out_unlock;
180 } else if (unlikely(!page)) {
181 break;
182 }
183 pfn = page_to_pfn(page);
184 }
185
186 ret = vm_insert_mixed(vma, address, pfn);
187 /*
188 * Somebody beat us to this PTE or prefaulting to
189 * an already populated PTE, or prefaulting error.
190 */
191
192 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
193 break;
194 else if (unlikely(ret != 0)) {
195 retval =
196 (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
197 goto out_unlock;
198
199 }
200
201 address += PAGE_SIZE;
202 if (unlikely(++page_offset >= page_last))
203 break;
204 }
205
206out_unlock:
207 ttm_bo_unreserve(bo);
208 return retval;
209}
210
211static void ttm_bo_vm_open(struct vm_area_struct *vma)
212{
213 struct ttm_buffer_object *bo =
214 (struct ttm_buffer_object *)vma->vm_private_data;
215
216 (void)ttm_bo_reference(bo);
217}
218
219static void ttm_bo_vm_close(struct vm_area_struct *vma)
220{
221 struct ttm_buffer_object *bo =
222 (struct ttm_buffer_object *)vma->vm_private_data;
223
224 ttm_bo_unref(&bo);
225 vma->vm_private_data = NULL;
226}
227
228static struct vm_operations_struct ttm_bo_vm_ops = {
229 .fault = ttm_bo_vm_fault,
230 .open = ttm_bo_vm_open,
231 .close = ttm_bo_vm_close
232};
233
234int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
235 struct ttm_bo_device *bdev)
236{
237 struct ttm_bo_driver *driver;
238 struct ttm_buffer_object *bo;
239 int ret;
240
241 read_lock(&bdev->vm_lock);
242 bo = ttm_bo_vm_lookup_rb(bdev, vma->vm_pgoff,
243 (vma->vm_end - vma->vm_start) >> PAGE_SHIFT);
244 if (likely(bo != NULL))
245 ttm_bo_reference(bo);
246 read_unlock(&bdev->vm_lock);
247
248 if (unlikely(bo == NULL)) {
249 printk(KERN_ERR TTM_PFX
250 "Could not find buffer object to map.\n");
251 return -EINVAL;
252 }
253
254 driver = bo->bdev->driver;
255 if (unlikely(!driver->verify_access)) {
256 ret = -EPERM;
257 goto out_unref;
258 }
259 ret = driver->verify_access(bo, filp);
260 if (unlikely(ret != 0))
261 goto out_unref;
262
263 vma->vm_ops = &ttm_bo_vm_ops;
264
265 /*
266 * Note: We're transferring the bo reference to
267 * vma->vm_private_data here.
268 */
269
270 vma->vm_private_data = bo;
271 vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
272 return 0;
273out_unref:
274 ttm_bo_unref(&bo);
275 return ret;
276}
277EXPORT_SYMBOL(ttm_bo_mmap);
278
279int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
280{
281 if (vma->vm_pgoff != 0)
282 return -EACCES;
283
284 vma->vm_ops = &ttm_bo_vm_ops;
285 vma->vm_private_data = ttm_bo_reference(bo);
286 vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
287 return 0;
288}
289EXPORT_SYMBOL(ttm_fbdev_mmap);
290
291
292ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
293 const char __user *wbuf, char __user *rbuf, size_t count,
294 loff_t *f_pos, bool write)
295{
296 struct ttm_buffer_object *bo;
297 struct ttm_bo_driver *driver;
298 struct ttm_bo_kmap_obj map;
299 unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
300 unsigned long kmap_offset;
301 unsigned long kmap_end;
302 unsigned long kmap_num;
303 size_t io_size;
304 unsigned int page_offset;
305 char *virtual;
306 int ret;
307 bool no_wait = false;
308 bool dummy;
309
310 read_lock(&bdev->vm_lock);
311 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
312 if (likely(bo != NULL))
313 ttm_bo_reference(bo);
314 read_unlock(&bdev->vm_lock);
315
316 if (unlikely(bo == NULL))
317 return -EFAULT;
318
319 driver = bo->bdev->driver;
320 if (unlikely(driver->verify_access)) {
321 ret = -EPERM;
322 goto out_unref;
323 }
324
325 ret = driver->verify_access(bo, filp);
326 if (unlikely(ret != 0))
327 goto out_unref;
328
329 kmap_offset = dev_offset - bo->vm_node->start;
330 if (unlikely(kmap_offset) >= bo->num_pages) {
331 ret = -EFBIG;
332 goto out_unref;
333 }
334
335 page_offset = *f_pos & ~PAGE_MASK;
336 io_size = bo->num_pages - kmap_offset;
337 io_size = (io_size << PAGE_SHIFT) - page_offset;
338 if (count < io_size)
339 io_size = count;
340
341 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
342 kmap_num = kmap_end - kmap_offset + 1;
343
344 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
345
346 switch (ret) {
347 case 0:
348 break;
349 case -ERESTART:
350 ret = -EINTR;
351 goto out_unref;
352 case -EBUSY:
353 ret = -EAGAIN;
354 goto out_unref;
355 default:
356 goto out_unref;
357 }
358
359 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
360 if (unlikely(ret != 0)) {
361 ttm_bo_unreserve(bo);
362 goto out_unref;
363 }
364
365 virtual = ttm_kmap_obj_virtual(&map, &dummy);
366 virtual += page_offset;
367
368 if (write)
369 ret = copy_from_user(virtual, wbuf, io_size);
370 else
371 ret = copy_to_user(rbuf, virtual, io_size);
372
373 ttm_bo_kunmap(&map);
374 ttm_bo_unreserve(bo);
375 ttm_bo_unref(&bo);
376
377 if (unlikely(ret != 0))
378 return -EFBIG;
379
380 *f_pos += io_size;
381
382 return io_size;
383out_unref:
384 ttm_bo_unref(&bo);
385 return ret;
386}
387
388ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
389 char __user *rbuf, size_t count, loff_t *f_pos,
390 bool write)
391{
392 struct ttm_bo_kmap_obj map;
393 unsigned long kmap_offset;
394 unsigned long kmap_end;
395 unsigned long kmap_num;
396 size_t io_size;
397 unsigned int page_offset;
398 char *virtual;
399 int ret;
400 bool no_wait = false;
401 bool dummy;
402
403 kmap_offset = (*f_pos >> PAGE_SHIFT);
404 if (unlikely(kmap_offset) >= bo->num_pages)
405 return -EFBIG;
406
407 page_offset = *f_pos & ~PAGE_MASK;
408 io_size = bo->num_pages - kmap_offset;
409 io_size = (io_size << PAGE_SHIFT) - page_offset;
410 if (count < io_size)
411 io_size = count;
412
413 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
414 kmap_num = kmap_end - kmap_offset + 1;
415
416 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
417
418 switch (ret) {
419 case 0:
420 break;
421 case -ERESTART:
422 return -EINTR;
423 case -EBUSY:
424 return -EAGAIN;
425 default:
426 return ret;
427 }
428
429 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
430 if (unlikely(ret != 0)) {
431 ttm_bo_unreserve(bo);
432 return ret;
433 }
434
435 virtual = ttm_kmap_obj_virtual(&map, &dummy);
436 virtual += page_offset;
437
438 if (write)
439 ret = copy_from_user(virtual, wbuf, io_size);
440 else
441 ret = copy_to_user(rbuf, virtual, io_size);
442
443 ttm_bo_kunmap(&map);
444 ttm_bo_unreserve(bo);
445 ttm_bo_unref(&bo);
446
447 if (unlikely(ret != 0))
448 return ret;
449
450 *f_pos += io_size;
451
452 return io_size;
453}