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
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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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.
26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
31 #define pr_fmt(fmt) "[TTM] " fmt
33 #include <ttm/ttm_module.h>
34 #include <ttm/ttm_bo_driver.h>
35 #include <ttm/ttm_placement.h>
36 #include <drm/drm_vma_manager.h>
38 #include <linux/rbtree.h>
39 #include <linux/module.h>
40 #include <linux/uaccess.h>
42 #define TTM_BO_VM_NUM_PREFAULT 16
44 static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
45 struct vm_area_struct *vma,
48 struct ttm_bo_device *bdev = bo->bdev;
51 spin_lock(&bdev->fence_lock);
52 if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
56 * Quick non-stalling check for idle.
58 ret = ttm_bo_wait(bo, false, false, true);
63 * If possible, avoid waiting for GPU with mmap_sem
66 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
68 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
71 up_read(&vma->vm_mm->mmap_sem);
72 (void) ttm_bo_wait(bo, false, true, false);
79 ret = ttm_bo_wait(bo, false, true, false);
80 if (unlikely(ret != 0))
81 ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
85 spin_unlock(&bdev->fence_lock);
89 static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
91 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
93 struct ttm_bo_device *bdev = bo->bdev;
94 unsigned long page_offset;
95 unsigned long page_last;
97 struct ttm_tt *ttm = NULL;
101 unsigned long address = (unsigned long)vmf->virtual_address;
102 int retval = VM_FAULT_NOPAGE;
103 struct ttm_mem_type_manager *man =
104 &bdev->man[bo->mem.mem_type];
105 struct vm_area_struct cvma;
108 * Work around locking order reversal in fault / nopfn
109 * between mmap_sem and bo_reserve: Perform a trylock operation
110 * for reserve, and if it fails, retry the fault after waiting
111 * for the buffer to become unreserved.
113 ret = ttm_bo_reserve(bo, true, true, false, NULL);
114 if (unlikely(ret != 0)) {
116 return VM_FAULT_NOPAGE;
118 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
119 if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
120 up_read(&vma->vm_mm->mmap_sem);
121 (void) ttm_bo_wait_unreserved(bo);
124 return VM_FAULT_RETRY;
128 * If we'd want to change locking order to
129 * mmap_sem -> bo::reserve, we'd use a blocking reserve here
130 * instead of retrying the fault...
132 return VM_FAULT_NOPAGE;
135 if (bdev->driver->fault_reserve_notify) {
136 ret = bdev->driver->fault_reserve_notify(bo);
142 retval = VM_FAULT_NOPAGE;
145 retval = VM_FAULT_SIGBUS;
151 * Wait for buffer data in transit, due to a pipelined
154 ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
155 if (unlikely(ret != 0)) {
160 ret = ttm_mem_io_lock(man, true);
161 if (unlikely(ret != 0)) {
162 retval = VM_FAULT_NOPAGE;
165 ret = ttm_mem_io_reserve_vm(bo);
166 if (unlikely(ret != 0)) {
167 retval = VM_FAULT_SIGBUS;
171 page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
172 drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;
173 page_last = vma_pages(vma) +
174 drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;
176 if (unlikely(page_offset >= bo->num_pages)) {
177 retval = VM_FAULT_SIGBUS;
182 * Make a local vma copy to modify the page_prot member
183 * and vm_flags if necessary. The vma parameter is protected
184 * by mmap_sem in write mode.
187 cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);
189 if (bo->mem.bus.is_iomem) {
190 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
194 if (!(bo->mem.placement & TTM_PL_FLAG_CACHED))
195 cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
198 /* Allocate all page at once, most common usage */
199 if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
200 retval = VM_FAULT_OOM;
206 * Speculatively prefault a number of pages. Only error on
209 for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
210 if (bo->mem.bus.is_iomem)
211 pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
213 page = ttm->pages[page_offset];
214 if (unlikely(!page && i == 0)) {
215 retval = VM_FAULT_OOM;
217 } else if (unlikely(!page)) {
220 pfn = page_to_pfn(page);
223 ret = vm_insert_mixed(&cvma, address, pfn);
225 * Somebody beat us to this PTE or prefaulting to
226 * an already populated PTE, or prefaulting error.
229 if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
231 else if (unlikely(ret != 0)) {
233 (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
237 address += PAGE_SIZE;
238 if (unlikely(++page_offset >= page_last))
242 ttm_mem_io_unlock(man);
244 ttm_bo_unreserve(bo);
248 static void ttm_bo_vm_open(struct vm_area_struct *vma)
250 struct ttm_buffer_object *bo =
251 (struct ttm_buffer_object *)vma->vm_private_data;
253 (void)ttm_bo_reference(bo);
256 static void ttm_bo_vm_close(struct vm_area_struct *vma)
258 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;
261 vma->vm_private_data = NULL;
264 static const struct vm_operations_struct ttm_bo_vm_ops = {
265 .fault = ttm_bo_vm_fault,
266 .open = ttm_bo_vm_open,
267 .close = ttm_bo_vm_close
270 static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
271 unsigned long offset,
274 struct drm_vma_offset_node *node;
275 struct ttm_buffer_object *bo = NULL;
277 drm_vma_offset_lock_lookup(&bdev->vma_manager);
279 node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
281 bo = container_of(node, struct ttm_buffer_object, vma_node);
282 if (!kref_get_unless_zero(&bo->kref))
286 drm_vma_offset_unlock_lookup(&bdev->vma_manager);
289 pr_err("Could not find buffer object to map\n");
294 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
295 struct ttm_bo_device *bdev)
297 struct ttm_bo_driver *driver;
298 struct ttm_buffer_object *bo;
301 bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
305 driver = bo->bdev->driver;
306 if (unlikely(!driver->verify_access)) {
310 ret = driver->verify_access(bo, filp);
311 if (unlikely(ret != 0))
314 vma->vm_ops = &ttm_bo_vm_ops;
317 * Note: We're transferring the bo reference to
318 * vma->vm_private_data here.
321 vma->vm_private_data = bo;
322 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP;
328 EXPORT_SYMBOL(ttm_bo_mmap);
330 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
332 if (vma->vm_pgoff != 0)
335 vma->vm_ops = &ttm_bo_vm_ops;
336 vma->vm_private_data = ttm_bo_reference(bo);
337 vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
340 EXPORT_SYMBOL(ttm_fbdev_mmap);