1 /**************************************************************************
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
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
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11 * permit persons to whom the Software is furnished to do so, subject to
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14 * The above copyright notice and this permission notice (including the
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18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
31 * Copyright (c) 2013 The FreeBSD Foundation
32 * All rights reserved.
34 * Portions of this software were developed by Konstantin Belousov
35 * <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
37 *$FreeBSD: head/sys/dev/drm2/ttm/ttm_bo_vm.c 253710 2013-07-27 16:44:37Z kib $
42 #define pr_fmt(fmt) "[TTM] " fmt
44 #include <drm/ttm/ttm_module.h>
45 #include <drm/ttm/ttm_bo_driver.h>
46 #include <drm/ttm/ttm_placement.h>
48 #include <vm/vm_page.h>
49 #include <linux/errno.h>
50 #include <linux/export.h>
52 RB_GENERATE(ttm_bo_device_buffer_objects, ttm_buffer_object, vm_rb,
53 ttm_bo_cmp_rb_tree_items);
56 #define TTM_BO_VM_NUM_PREFAULT 16
59 ttm_bo_cmp_rb_tree_items(struct ttm_buffer_object *a,
60 struct ttm_buffer_object *b)
62 if (a->vm_node->start < b->vm_node->start) {
64 } else if (a->vm_node->start > b->vm_node->start) {
72 static struct ttm_buffer_object *ttm_bo_vm_lookup_rb(struct ttm_bo_device *bdev,
73 unsigned long page_start,
74 unsigned long num_pages)
76 unsigned long cur_offset;
77 struct ttm_buffer_object *bo;
78 struct ttm_buffer_object *best_bo = NULL;
80 bo = RB_ROOT(&bdev->addr_space_rb);
82 cur_offset = bo->vm_node->start;
83 if (page_start >= cur_offset) {
85 if (page_start == cur_offset)
87 bo = RB_RIGHT(bo, vm_rb);
89 bo = RB_LEFT(bo, vm_rb);
92 if (unlikely(best_bo == NULL))
95 if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
96 (page_start + num_pages)))
103 ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset,
104 int prot, vm_page_t *mres)
106 struct ttm_buffer_object *bo = vm_obj->handle;
107 struct ttm_bo_device *bdev = bo->bdev;
108 struct ttm_tt *ttm = NULL;
109 vm_page_t m, m1, oldm;
111 int retval = VM_PAGER_OK;
112 struct ttm_mem_type_manager *man =
113 &bdev->man[bo->mem.mem_type];
115 vm_object_pip_add(vm_obj, 1);
118 vm_page_remove(oldm);
123 VM_OBJECT_WUNLOCK(vm_obj);
127 ret = ttm_bo_reserve(bo, false, false, false, 0);
128 if (unlikely(ret != 0)) {
135 if (bdev->driver->fault_reserve_notify) {
136 ret = bdev->driver->fault_reserve_notify(bo);
146 retval = VM_PAGER_ERROR;
152 * Wait for buffer data in transit, due to a pipelined
156 lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
157 if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
159 * Here, the behavior differs between Linux and FreeBSD.
161 * On Linux, the wait is interruptible (3rd argument to
162 * ttm_bo_wait). There must be some mechanism to resume
163 * page fault handling, once the signal is processed.
165 * On FreeBSD, the wait is uninteruptible. This is not a
166 * problem as we can't end up with an unkillable process
167 * here, because the wait will eventually time out.
169 * An example of this situation is the Xorg process
170 * which uses SIGALRM internally. The signal could
171 * interrupt the wait, causing the page fault to fail
172 * and the process to receive SIGSEGV.
174 ret = ttm_bo_wait(bo, false, false, false);
175 lockmgr(&bdev->fence_lock, LK_RELEASE);
176 if (unlikely(ret != 0)) {
177 retval = VM_PAGER_ERROR;
181 lockmgr(&bdev->fence_lock, LK_RELEASE);
183 ret = ttm_mem_io_lock(man, true);
184 if (unlikely(ret != 0)) {
185 retval = VM_PAGER_ERROR;
188 ret = ttm_mem_io_reserve_vm(bo);
189 if (unlikely(ret != 0)) {
190 retval = VM_PAGER_ERROR;
195 * Strictly, we're not allowed to modify vma->vm_page_prot here,
196 * since the mmap_sem is only held in read mode. However, we
197 * modify only the caching bits of vma->vm_page_prot and
198 * consider those bits protected by
199 * the bo->mutex, as we should be the only writers.
200 * There shouldn't really be any readers of these bits except
201 * within vm_insert_mixed()? fork?
203 * TODO: Add a list of vmas to the bo, and change the
204 * vma->vm_page_prot when the object changes caching policy, with
205 * the correct locks held.
207 if (!bo->mem.bus.is_iomem) {
208 /* Allocate all page at once, most common usage */
210 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
211 retval = VM_PAGER_ERROR;
216 if (bo->mem.bus.is_iomem) {
217 m = vm_phys_fictitious_to_vm_page(bo->mem.bus.base +
218 bo->mem.bus.offset + offset);
219 pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement));
222 m = ttm->pages[OFF_TO_IDX(offset)];
224 retval = VM_PAGER_ERROR;
227 pmap_page_set_memattr(m,
228 (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
229 VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement));
232 VM_OBJECT_WLOCK(vm_obj);
233 if ((m->flags & PG_BUSY) != 0) {
235 vm_page_sleep(m, "ttmpbs");
237 ttm_mem_io_unlock(man);
238 ttm_bo_unreserve(bo);
241 m->valid = VM_PAGE_BITS_ALL;
243 m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
245 vm_page_insert(m, vm_obj, OFF_TO_IDX(offset));
248 ("inconsistent insert bo %p m %p m1 %p offset %jx",
249 bo, m, m1, (uintmax_t)offset));
251 vm_page_busy_try(m, FALSE);
258 ttm_mem_io_unlock(man);
260 ttm_bo_unreserve(bo);
261 vm_object_pip_wakeup(vm_obj);
265 VM_OBJECT_WLOCK(vm_obj);
269 VM_OBJECT_WLOCK(vm_obj);
274 ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
275 vm_ooffset_t foff, struct ucred *cred, u_short *color)
279 * On Linux, a reference to the buffer object is acquired here.
280 * The reason is that this function is not called when the
281 * mmap() is initialized, but only when a process forks for
282 * instance. Therefore on Linux, the reference on the bo is
283 * acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's
284 * then released in ttm_bo_vm_close().
286 * Here, this function is called during mmap() intialization.
287 * Thus, the reference acquired in ttm_bo_mmap_single() is
295 ttm_bo_vm_dtor(void *handle)
297 struct ttm_buffer_object *bo = handle;
302 static struct cdev_pager_ops ttm_pager_ops = {
303 .cdev_pg_fault = ttm_bo_vm_fault,
304 .cdev_pg_ctor = ttm_bo_vm_ctor,
305 .cdev_pg_dtor = ttm_bo_vm_dtor
309 ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size,
310 struct vm_object **obj_res, int nprot)
312 struct ttm_bo_driver *driver;
313 struct ttm_buffer_object *bo;
314 struct vm_object *vm_obj;
319 lockmgr(&bdev->vm_lock, LK_EXCLUSIVE);
320 bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size));
321 if (likely(bo != NULL))
323 lockmgr(&bdev->vm_lock, LK_RELEASE);
325 if (unlikely(bo == NULL)) {
326 kprintf("[TTM] Could not find buffer object to map\n");
330 driver = bo->bdev->driver;
331 if (unlikely(!driver->verify_access)) {
335 ret = -driver->verify_access(bo);
336 if (unlikely(ret != 0))
339 vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops,
340 size, nprot, 0, curthread->td_ucred);
342 if (vm_obj == NULL) {
347 * Note: We're transferring the bo reference to vm_obj->handle here.
356 EXPORT_SYMBOL(ttm_bo_mmap);
359 ttm_bo_release_mmap(struct ttm_buffer_object *bo)
365 vm_obj = cdev_pager_lookup(bo);
369 VM_OBJECT_WLOCK(vm_obj);
370 for (i = 0; i < bo->num_pages; i++) {
371 m = vm_page_lookup_busy_wait(vm_obj, i, TRUE, "ttm_unm");
374 cdev_pager_free_page(vm_obj, m);
376 VM_OBJECT_WUNLOCK(vm_obj);
378 vm_object_deallocate(vm_obj);
382 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
384 if (vma->vm_pgoff != 0)
387 vma->vm_ops = &ttm_bo_vm_ops;
388 vma->vm_private_data = ttm_bo_reference(bo);
389 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
392 EXPORT_SYMBOL(ttm_fbdev_mmap);
395 ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
396 const char __user *wbuf, char __user *rbuf, size_t count,
397 loff_t *f_pos, bool write)
399 struct ttm_buffer_object *bo;
400 struct ttm_bo_driver *driver;
401 struct ttm_bo_kmap_obj map;
402 unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
403 unsigned long kmap_offset;
404 unsigned long kmap_end;
405 unsigned long kmap_num;
407 unsigned int page_offset;
410 bool no_wait = false;
413 lockmgr(&bdev->vm_lock, LK_EXCLUSIVE);
414 bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
415 if (likely(bo != NULL))
416 ttm_bo_reference(bo);
417 lockmgr(&bdev->vm_lock, LK_RELEASE);
419 if (unlikely(bo == NULL))
422 driver = bo->bdev->driver;
423 if (unlikely(!driver->verify_access)) {
428 ret = driver->verify_access(bo, filp);
429 if (unlikely(ret != 0))
432 kmap_offset = dev_offset - bo->vm_node->start;
433 if (unlikely(kmap_offset >= bo->num_pages)) {
438 page_offset = *f_pos & ~PAGE_MASK;
439 io_size = bo->num_pages - kmap_offset;
440 io_size = (io_size << PAGE_SHIFT) - page_offset;
444 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
445 kmap_num = kmap_end - kmap_offset + 1;
447 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
459 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
460 if (unlikely(ret != 0)) {
461 ttm_bo_unreserve(bo);
465 virtual = ttm_kmap_obj_virtual(&map, &dummy);
466 virtual += page_offset;
469 ret = copy_from_user(virtual, wbuf, io_size);
471 ret = copy_to_user(rbuf, virtual, io_size);
474 ttm_bo_unreserve(bo);
477 if (unlikely(ret != 0))
488 ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
489 char __user *rbuf, size_t count, loff_t *f_pos,
492 struct ttm_bo_kmap_obj map;
493 unsigned long kmap_offset;
494 unsigned long kmap_end;
495 unsigned long kmap_num;
497 unsigned int page_offset;
500 bool no_wait = false;
503 kmap_offset = (*f_pos >> PAGE_SHIFT);
504 if (unlikely(kmap_offset >= bo->num_pages))
507 page_offset = *f_pos & ~PAGE_MASK;
508 io_size = bo->num_pages - kmap_offset;
509 io_size = (io_size << PAGE_SHIFT) - page_offset;
513 kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
514 kmap_num = kmap_end - kmap_offset + 1;
516 ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
527 ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
528 if (unlikely(ret != 0)) {
529 ttm_bo_unreserve(bo);
533 virtual = ttm_kmap_obj_virtual(&map, &dummy);
534 virtual += page_offset;
537 ret = copy_from_user(virtual, wbuf, io_size);
539 ret = copy_to_user(rbuf, virtual, io_size);
542 ttm_bo_unreserve(bo);
545 if (unlikely(ret != 0))