2 * SPDX-License-Identifier: MIT
4 * Copyright © 2014-2016 Intel Corporation
7 #include <linux/anon_inodes.h>
8 #include <linux/mman.h>
9 #include <linux/pfn_t.h>
10 #include <linux/sizes.h>
12 #include "gt/intel_gt.h"
13 #include "gt/intel_gt_requests.h"
16 #include "i915_gem_gtt.h"
17 #include "i915_gem_ioctls.h"
18 #include "i915_gem_object.h"
19 #include "i915_gem_mman.h"
20 #include "i915_trace.h"
21 #include "i915_user_extensions.h"
22 #include "i915_gem_ttm.h"
26 __vma_matches(struct vm_area_struct *vma, struct file *filp,
27 unsigned long addr, unsigned long size)
29 if (vma->vm_file != filp)
32 return vma->vm_start == addr &&
33 (vma->vm_end - vma->vm_start) == PAGE_ALIGN(size);
37 * i915_gem_mmap_ioctl - Maps the contents of an object, returning the address
40 * @data: ioctl data blob
43 * While the mapping holds a reference on the contents of the object, it doesn't
44 * imply a ref on the object itself.
48 * DRM driver writers who look a this function as an example for how to do GEM
49 * mmap support, please don't implement mmap support like here. The modern way
50 * to implement DRM mmap support is with an mmap offset ioctl (like
51 * i915_gem_mmap_gtt) and then using the mmap syscall on the DRM fd directly.
52 * That way debug tooling like valgrind will understand what's going on, hiding
53 * the mmap call in a driver private ioctl will break that. The i915 driver only
54 * does cpu mmaps this way because we didn't know better.
57 i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
58 struct drm_file *file)
60 struct drm_i915_private *i915 = to_i915(dev);
61 struct drm_i915_gem_mmap *args = data;
62 struct drm_i915_gem_object *obj;
66 * mmap ioctl is disallowed for all discrete platforms,
67 * and for all platforms with GRAPHICS_VER > 12.
69 if (IS_DGFX(i915) || GRAPHICS_VER(i915) > 12)
72 if (args->flags & ~(I915_MMAP_WC))
75 if (args->flags & I915_MMAP_WC && !boot_cpu_has(X86_FEATURE_PAT))
78 obj = i915_gem_object_lookup(file, args->handle);
82 /* prime objects have no backing filp to GEM mmap
85 if (!obj->base.filp) {
90 if (range_overflows(args->offset, args->size, (u64)obj->base.size)) {
95 addr = vm_mmap(obj->base.filp, 0, args->size,
96 PROT_READ | PROT_WRITE, MAP_SHARED,
98 if (IS_ERR_VALUE(addr))
101 if (args->flags & I915_MMAP_WC) {
102 struct mm_struct *mm = current->mm;
103 struct vm_area_struct *vma;
105 if (mmap_write_lock_killable(mm)) {
109 vma = find_vma(mm, addr);
110 if (vma && __vma_matches(vma, obj->base.filp, addr, args->size))
112 pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
115 mmap_write_unlock(mm);
116 if (IS_ERR_VALUE(addr))
119 i915_gem_object_put(obj);
121 args->addr_ptr = (u64)addr;
125 i915_gem_object_put(obj);
129 static unsigned int tile_row_pages(const struct drm_i915_gem_object *obj)
131 return i915_gem_object_get_tile_row_size(obj) >> PAGE_SHIFT;
135 * i915_gem_mmap_gtt_version - report the current feature set for GTT mmaps
137 * A history of the GTT mmap interface:
139 * 0 - Everything had to fit into the GTT. Both parties of a memcpy had to
140 * aligned and suitable for fencing, and still fit into the available
141 * mappable space left by the pinned display objects. A classic problem
142 * we called the page-fault-of-doom where we would ping-pong between
143 * two objects that could not fit inside the GTT and so the memcpy
144 * would page one object in at the expense of the other between every
147 * 1 - Objects can be any size, and have any compatible fencing (X Y, or none
148 * as set via i915_gem_set_tiling() [DRM_I915_GEM_SET_TILING]). If the
149 * object is too large for the available space (or simply too large
150 * for the mappable aperture!), a view is created instead and faulted
151 * into userspace. (This view is aligned and sized appropriately for
154 * 2 - Recognise WC as a separate cache domain so that we can flush the
155 * delayed writes via GTT before performing direct access via WC.
157 * 3 - Remove implicit set-domain(GTT) and synchronisation on initial
158 * pagefault; swapin remains transparent.
160 * 4 - Support multiple fault handlers per object depending on object's
161 * backing storage (a.k.a. MMAP_OFFSET).
165 * * snoopable objects cannot be accessed via the GTT. It can cause machine
166 * hangs on some architectures, corruption on others. An attempt to service
167 * a GTT page fault from a snoopable object will generate a SIGBUS.
169 * * the object must be able to fit into RAM (physical memory, though no
170 * limited to the mappable aperture).
175 * * a new GTT page fault will synchronize rendering from the GPU and flush
176 * all data to system memory. Subsequent access will not be synchronized.
178 * * all mappings are revoked on runtime device suspend.
180 * * there are only 8, 16 or 32 fence registers to share between all users
181 * (older machines require fence register for display and blitter access
182 * as well). Contention of the fence registers will cause the previous users
183 * to be unmapped and any new access will generate new page faults.
185 * * running out of memory while servicing a fault may generate a SIGBUS,
186 * rather than the expected SIGSEGV.
188 int i915_gem_mmap_gtt_version(void)
193 static inline struct i915_ggtt_view
194 compute_partial_view(const struct drm_i915_gem_object *obj,
198 struct i915_ggtt_view view;
200 if (i915_gem_object_is_tiled(obj))
201 chunk = roundup(chunk, tile_row_pages(obj) ?: 1);
203 view.type = I915_GGTT_VIEW_PARTIAL;
204 view.partial.offset = rounddown(page_offset, chunk);
206 min_t(unsigned int, chunk,
207 (obj->base.size >> PAGE_SHIFT) - view.partial.offset);
209 /* If the partial covers the entire object, just create a normal VMA. */
210 if (chunk >= obj->base.size >> PAGE_SHIFT)
211 view.type = I915_GGTT_VIEW_NORMAL;
216 static vm_fault_t i915_error_to_vmf_fault(int err)
220 WARN_ONCE(err, "unhandled error in %s: %i\n", __func__, err);
222 case -EIO: /* shmemfs failure from swap device */
223 case -EFAULT: /* purged object */
224 case -ENODEV: /* bad object, how did you get here! */
225 case -ENXIO: /* unable to access backing store (on device) */
226 return VM_FAULT_SIGBUS;
228 case -ENOMEM: /* our allocation failure */
233 case -ENOSPC: /* transient failure to evict? */
238 * EBUSY is ok: this just means that another thread
239 * already did the job.
241 return VM_FAULT_NOPAGE;
245 static vm_fault_t vm_fault_cpu(struct vm_fault *vmf)
247 struct vm_area_struct *area = vmf->vma;
248 struct i915_mmap_offset *mmo = area->vm_private_data;
249 struct drm_i915_gem_object *obj = mmo->obj;
250 resource_size_t iomap;
253 /* Sanity check that we allow writing into this object */
254 if (unlikely(i915_gem_object_is_readonly(obj) &&
255 area->vm_flags & VM_WRITE))
256 return VM_FAULT_SIGBUS;
258 if (i915_gem_object_lock_interruptible(obj, NULL))
259 return VM_FAULT_NOPAGE;
261 err = i915_gem_object_pin_pages(obj);
266 if (!i915_gem_object_has_struct_page(obj)) {
267 iomap = obj->mm.region->iomap.base;
268 iomap -= obj->mm.region->region.start;
271 /* PTEs are revoked in obj->ops->put_pages() */
272 err = remap_io_sg(area,
273 area->vm_start, area->vm_end - area->vm_start,
274 obj->mm.pages->sgl, iomap);
276 if (area->vm_flags & VM_WRITE) {
277 GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
278 obj->mm.dirty = true;
281 i915_gem_object_unpin_pages(obj);
284 i915_gem_object_unlock(obj);
285 return i915_error_to_vmf_fault(err);
288 static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
290 #define MIN_CHUNK_PAGES (SZ_1M >> PAGE_SHIFT)
291 struct vm_area_struct *area = vmf->vma;
292 struct i915_mmap_offset *mmo = area->vm_private_data;
293 struct drm_i915_gem_object *obj = mmo->obj;
294 struct drm_device *dev = obj->base.dev;
295 struct drm_i915_private *i915 = to_i915(dev);
296 struct intel_runtime_pm *rpm = &i915->runtime_pm;
297 struct i915_ggtt *ggtt = &i915->ggtt;
298 bool write = area->vm_flags & VM_WRITE;
299 struct i915_gem_ww_ctx ww;
300 intel_wakeref_t wakeref;
301 struct i915_vma *vma;
306 /* We don't use vmf->pgoff since that has the fake offset */
307 page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT;
309 trace_i915_gem_object_fault(obj, page_offset, true, write);
311 wakeref = intel_runtime_pm_get(rpm);
313 i915_gem_ww_ctx_init(&ww, true);
315 ret = i915_gem_object_lock(obj, &ww);
319 /* Sanity check that we allow writing into this object */
320 if (i915_gem_object_is_readonly(obj) && write) {
325 ret = i915_gem_object_pin_pages(obj);
329 ret = intel_gt_reset_trylock(ggtt->vm.gt, &srcu);
333 /* Now pin it into the GTT as needed */
334 vma = i915_gem_object_ggtt_pin_ww(obj, &ww, NULL, 0, 0,
336 PIN_NONBLOCK /* NOWARN */ |
338 if (IS_ERR(vma) && vma != ERR_PTR(-EDEADLK)) {
339 /* Use a partial view if it is bigger than available space */
340 struct i915_ggtt_view view =
341 compute_partial_view(obj, page_offset, MIN_CHUNK_PAGES);
344 flags = PIN_MAPPABLE | PIN_NOSEARCH;
345 if (view.type == I915_GGTT_VIEW_NORMAL)
346 flags |= PIN_NONBLOCK; /* avoid warnings for pinned */
349 * Userspace is now writing through an untracked VMA, abandon
350 * all hope that the hardware is able to track future writes.
353 vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags);
354 if (IS_ERR(vma) && vma != ERR_PTR(-EDEADLK)) {
355 flags = PIN_MAPPABLE;
356 view.type = I915_GGTT_VIEW_PARTIAL;
357 vma = i915_gem_object_ggtt_pin_ww(obj, &ww, &view, 0, 0, flags);
360 /* The entire mappable GGTT is pinned? Unexpected! */
361 GEM_BUG_ON(vma == ERR_PTR(-ENOSPC));
368 /* Access to snoopable pages through the GTT is incoherent. */
369 if (obj->cache_level != I915_CACHE_NONE && !HAS_LLC(i915)) {
374 ret = i915_vma_pin_fence(vma);
378 /* Finally, remap it using the new GTT offset */
379 ret = remap_io_mapping(area,
380 area->vm_start + (vma->ggtt_view.partial.offset << PAGE_SHIFT),
381 (ggtt->gmadr.start + vma->node.start) >> PAGE_SHIFT,
382 min_t(u64, vma->size, area->vm_end - area->vm_start),
387 assert_rpm_wakelock_held(rpm);
389 /* Mark as being mmapped into userspace for later revocation */
390 mutex_lock(&i915->ggtt.vm.mutex);
391 if (!i915_vma_set_userfault(vma) && !obj->userfault_count++)
392 list_add(&obj->userfault_link, &i915->ggtt.userfault_list);
393 mutex_unlock(&i915->ggtt.vm.mutex);
395 /* Track the mmo associated with the fenced vma */
398 if (IS_ACTIVE(CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND))
399 intel_wakeref_auto(&i915->ggtt.userfault_wakeref,
400 msecs_to_jiffies_timeout(CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND));
403 GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
404 i915_vma_set_ggtt_write(vma);
405 obj->mm.dirty = true;
409 i915_vma_unpin_fence(vma);
411 __i915_vma_unpin(vma);
413 intel_gt_reset_unlock(ggtt->vm.gt, srcu);
415 i915_gem_object_unpin_pages(obj);
417 if (ret == -EDEADLK) {
418 ret = i915_gem_ww_ctx_backoff(&ww);
422 i915_gem_ww_ctx_fini(&ww);
423 intel_runtime_pm_put(rpm, wakeref);
424 return i915_error_to_vmf_fault(ret);
428 vm_access(struct vm_area_struct *area, unsigned long addr,
429 void *buf, int len, int write)
431 struct i915_mmap_offset *mmo = area->vm_private_data;
432 struct drm_i915_gem_object *obj = mmo->obj;
433 struct i915_gem_ww_ctx ww;
437 if (i915_gem_object_is_readonly(obj) && write)
440 addr -= area->vm_start;
441 if (addr >= obj->base.size)
444 i915_gem_ww_ctx_init(&ww, true);
446 err = i915_gem_object_lock(obj, &ww);
450 /* As this is primarily for debugging, let's focus on simplicity */
451 vaddr = i915_gem_object_pin_map(obj, I915_MAP_FORCE_WC);
453 err = PTR_ERR(vaddr);
458 memcpy(vaddr + addr, buf, len);
459 __i915_gem_object_flush_map(obj, addr, len);
461 memcpy(buf, vaddr + addr, len);
464 i915_gem_object_unpin_map(obj);
466 if (err == -EDEADLK) {
467 err = i915_gem_ww_ctx_backoff(&ww);
471 i915_gem_ww_ctx_fini(&ww);
479 void __i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj)
481 struct i915_vma *vma;
483 GEM_BUG_ON(!obj->userfault_count);
485 for_each_ggtt_vma(vma, obj)
486 i915_vma_revoke_mmap(vma);
488 GEM_BUG_ON(obj->userfault_count);
492 * It is vital that we remove the page mapping if we have mapped a tiled
493 * object through the GTT and then lose the fence register due to
494 * resource pressure. Similarly if the object has been moved out of the
495 * aperture, than pages mapped into userspace must be revoked. Removing the
496 * mapping will then trigger a page fault on the next user access, allowing
497 * fixup by vm_fault_gtt().
499 void i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj)
501 struct drm_i915_private *i915 = to_i915(obj->base.dev);
502 intel_wakeref_t wakeref;
505 * Serialisation between user GTT access and our code depends upon
506 * revoking the CPU's PTE whilst the mutex is held. The next user
507 * pagefault then has to wait until we release the mutex.
509 * Note that RPM complicates somewhat by adding an additional
510 * requirement that operations to the GGTT be made holding the RPM
513 wakeref = intel_runtime_pm_get(&i915->runtime_pm);
514 mutex_lock(&i915->ggtt.vm.mutex);
516 if (!obj->userfault_count)
519 __i915_gem_object_release_mmap_gtt(obj);
522 * Ensure that the CPU's PTE are revoked and there are not outstanding
523 * memory transactions from userspace before we return. The TLB
524 * flushing implied above by changing the PTE above *should* be
525 * sufficient, an extra barrier here just provides us with a bit
526 * of paranoid documentation about our requirement to serialise
527 * memory writes before touching registers / GSM.
532 mutex_unlock(&i915->ggtt.vm.mutex);
533 intel_runtime_pm_put(&i915->runtime_pm, wakeref);
536 void i915_gem_object_release_mmap_offset(struct drm_i915_gem_object *obj)
538 struct i915_mmap_offset *mmo, *mn;
540 spin_lock(&obj->mmo.lock);
541 rbtree_postorder_for_each_entry_safe(mmo, mn,
542 &obj->mmo.offsets, offset) {
544 * vma_node_unmap for GTT mmaps handled already in
545 * __i915_gem_object_release_mmap_gtt
547 if (mmo->mmap_type == I915_MMAP_TYPE_GTT)
550 spin_unlock(&obj->mmo.lock);
551 drm_vma_node_unmap(&mmo->vma_node,
552 obj->base.dev->anon_inode->i_mapping);
553 spin_lock(&obj->mmo.lock);
555 spin_unlock(&obj->mmo.lock);
558 static struct i915_mmap_offset *
559 lookup_mmo(struct drm_i915_gem_object *obj,
560 enum i915_mmap_type mmap_type)
564 spin_lock(&obj->mmo.lock);
565 rb = obj->mmo.offsets.rb_node;
567 struct i915_mmap_offset *mmo =
568 rb_entry(rb, typeof(*mmo), offset);
570 if (mmo->mmap_type == mmap_type) {
571 spin_unlock(&obj->mmo.lock);
575 if (mmo->mmap_type < mmap_type)
580 spin_unlock(&obj->mmo.lock);
585 static struct i915_mmap_offset *
586 insert_mmo(struct drm_i915_gem_object *obj, struct i915_mmap_offset *mmo)
588 struct rb_node *rb, **p;
590 spin_lock(&obj->mmo.lock);
592 p = &obj->mmo.offsets.rb_node;
594 struct i915_mmap_offset *pos;
597 pos = rb_entry(rb, typeof(*pos), offset);
599 if (pos->mmap_type == mmo->mmap_type) {
600 spin_unlock(&obj->mmo.lock);
601 drm_vma_offset_remove(obj->base.dev->vma_offset_manager,
607 if (pos->mmap_type < mmo->mmap_type)
612 rb_link_node(&mmo->offset, rb, p);
613 rb_insert_color(&mmo->offset, &obj->mmo.offsets);
614 spin_unlock(&obj->mmo.lock);
619 static struct i915_mmap_offset *
620 mmap_offset_attach(struct drm_i915_gem_object *obj,
621 enum i915_mmap_type mmap_type,
622 struct drm_file *file)
624 struct drm_i915_private *i915 = to_i915(obj->base.dev);
625 struct i915_mmap_offset *mmo;
628 GEM_BUG_ON(obj->ops->mmap_offset || obj->ops->mmap_ops);
630 mmo = lookup_mmo(obj, mmap_type);
634 mmo = kmalloc(sizeof(*mmo), GFP_KERNEL);
636 return ERR_PTR(-ENOMEM);
639 mmo->mmap_type = mmap_type;
640 drm_vma_node_reset(&mmo->vma_node);
642 err = drm_vma_offset_add(obj->base.dev->vma_offset_manager,
643 &mmo->vma_node, obj->base.size / PAGE_SIZE);
647 /* Attempt to reap some mmap space from dead objects */
648 err = intel_gt_retire_requests_timeout(&i915->gt, MAX_SCHEDULE_TIMEOUT);
652 i915_gem_drain_freed_objects(i915);
653 err = drm_vma_offset_add(obj->base.dev->vma_offset_manager,
654 &mmo->vma_node, obj->base.size / PAGE_SIZE);
659 mmo = insert_mmo(obj, mmo);
660 GEM_BUG_ON(lookup_mmo(obj, mmap_type) != mmo);
663 drm_vma_node_allow(&mmo->vma_node, file);
672 __assign_mmap_offset(struct drm_i915_gem_object *obj,
673 enum i915_mmap_type mmap_type,
674 u64 *offset, struct drm_file *file)
676 struct i915_mmap_offset *mmo;
678 if (i915_gem_object_never_mmap(obj))
681 if (obj->ops->mmap_offset) {
682 if (mmap_type != I915_MMAP_TYPE_FIXED)
685 *offset = obj->ops->mmap_offset(obj);
689 if (mmap_type == I915_MMAP_TYPE_FIXED)
692 if (mmap_type != I915_MMAP_TYPE_GTT &&
693 !i915_gem_object_has_struct_page(obj) &&
694 !i915_gem_object_has_iomem(obj))
697 mmo = mmap_offset_attach(obj, mmap_type, file);
701 *offset = drm_vma_node_offset_addr(&mmo->vma_node);
706 __assign_mmap_offset_handle(struct drm_file *file,
708 enum i915_mmap_type mmap_type,
711 struct drm_i915_gem_object *obj;
714 obj = i915_gem_object_lookup(file, handle);
718 err = i915_gem_object_lock_interruptible(obj, NULL);
721 err = __assign_mmap_offset(obj, mmap_type, offset, file);
722 i915_gem_object_unlock(obj);
724 i915_gem_object_put(obj);
729 i915_gem_dumb_mmap_offset(struct drm_file *file,
730 struct drm_device *dev,
734 enum i915_mmap_type mmap_type;
736 if (HAS_LMEM(to_i915(dev)))
737 mmap_type = I915_MMAP_TYPE_FIXED;
738 else if (boot_cpu_has(X86_FEATURE_PAT))
739 mmap_type = I915_MMAP_TYPE_WC;
740 else if (!i915_ggtt_has_aperture(&to_i915(dev)->ggtt))
743 mmap_type = I915_MMAP_TYPE_GTT;
745 return __assign_mmap_offset_handle(file, handle, mmap_type, offset);
749 * i915_gem_mmap_offset_ioctl - prepare an object for GTT mmap'ing
751 * @data: GTT mapping ioctl data
752 * @file: GEM object info
754 * Simply returns the fake offset to userspace so it can mmap it.
755 * The mmap call will end up in drm_gem_mmap(), which will set things
756 * up so we can get faults in the handler above.
758 * The fault handler will take care of binding the object into the GTT
759 * (since it may have been evicted to make room for something), allocating
760 * a fence register, and mapping the appropriate aperture address into
764 i915_gem_mmap_offset_ioctl(struct drm_device *dev, void *data,
765 struct drm_file *file)
767 struct drm_i915_private *i915 = to_i915(dev);
768 struct drm_i915_gem_mmap_offset *args = data;
769 enum i915_mmap_type type;
773 * Historically we failed to check args.pad and args.offset
774 * and so we cannot use those fields for user input and we cannot
775 * add -EINVAL for them as the ABI is fixed, i.e. old userspace
776 * may be feeding in garbage in those fields.
778 * if (args->pad) return -EINVAL; is verbotten!
781 err = i915_user_extensions(u64_to_user_ptr(args->extensions),
786 switch (args->flags) {
787 case I915_MMAP_OFFSET_GTT:
788 if (!i915_ggtt_has_aperture(&i915->ggtt))
790 type = I915_MMAP_TYPE_GTT;
793 case I915_MMAP_OFFSET_WC:
794 if (!boot_cpu_has(X86_FEATURE_PAT))
796 type = I915_MMAP_TYPE_WC;
799 case I915_MMAP_OFFSET_WB:
800 type = I915_MMAP_TYPE_WB;
803 case I915_MMAP_OFFSET_UC:
804 if (!boot_cpu_has(X86_FEATURE_PAT))
806 type = I915_MMAP_TYPE_UC;
809 case I915_MMAP_OFFSET_FIXED:
810 type = I915_MMAP_TYPE_FIXED;
817 return __assign_mmap_offset_handle(file, args->handle, type, &args->offset);
820 static void vm_open(struct vm_area_struct *vma)
822 struct i915_mmap_offset *mmo = vma->vm_private_data;
823 struct drm_i915_gem_object *obj = mmo->obj;
826 i915_gem_object_get(obj);
829 static void vm_close(struct vm_area_struct *vma)
831 struct i915_mmap_offset *mmo = vma->vm_private_data;
832 struct drm_i915_gem_object *obj = mmo->obj;
835 i915_gem_object_put(obj);
838 static const struct vm_operations_struct vm_ops_gtt = {
839 .fault = vm_fault_gtt,
845 static const struct vm_operations_struct vm_ops_cpu = {
846 .fault = vm_fault_cpu,
852 static int singleton_release(struct inode *inode, struct file *file)
854 struct drm_i915_private *i915 = file->private_data;
856 cmpxchg(&i915->gem.mmap_singleton, file, NULL);
857 drm_dev_put(&i915->drm);
862 static const struct file_operations singleton_fops = {
863 .owner = THIS_MODULE,
864 .release = singleton_release,
867 static struct file *mmap_singleton(struct drm_i915_private *i915)
872 file = READ_ONCE(i915->gem.mmap_singleton);
873 if (file && !get_file_rcu(file))
879 file = anon_inode_getfile("i915.gem", &singleton_fops, i915, O_RDWR);
883 /* Everyone shares a single global address space */
884 file->f_mapping = i915->drm.anon_inode->i_mapping;
886 smp_store_mb(i915->gem.mmap_singleton, file);
887 drm_dev_get(&i915->drm);
893 * This overcomes the limitation in drm_gem_mmap's assignment of a
894 * drm_gem_object as the vma->vm_private_data. Since we need to
895 * be able to resolve multiple mmap offsets which could be tied
896 * to a single gem object.
898 int i915_gem_mmap(struct file *filp, struct vm_area_struct *vma)
900 struct drm_vma_offset_node *node;
901 struct drm_file *priv = filp->private_data;
902 struct drm_device *dev = priv->minor->dev;
903 struct drm_i915_gem_object *obj = NULL;
904 struct i915_mmap_offset *mmo = NULL;
907 if (drm_dev_is_unplugged(dev))
911 drm_vma_offset_lock_lookup(dev->vma_offset_manager);
912 node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
915 if (node && drm_vma_node_is_allowed(node, priv)) {
917 * Skip 0-refcnted objects as it is in the process of being
918 * destroyed and will be invalid when the vma manager lock
921 if (!node->driver_private) {
922 mmo = container_of(node, struct i915_mmap_offset, vma_node);
923 obj = i915_gem_object_get_rcu(mmo->obj);
925 GEM_BUG_ON(obj && obj->ops->mmap_ops);
927 obj = i915_gem_object_get_rcu
928 (container_of(node, struct drm_i915_gem_object,
931 GEM_BUG_ON(obj && !obj->ops->mmap_ops);
934 drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
937 return node ? -EACCES : -EINVAL;
939 if (i915_gem_object_is_readonly(obj)) {
940 if (vma->vm_flags & VM_WRITE) {
941 i915_gem_object_put(obj);
944 vma->vm_flags &= ~VM_MAYWRITE;
947 anon = mmap_singleton(to_i915(dev));
949 i915_gem_object_put(obj);
950 return PTR_ERR(anon);
953 vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP | VM_IO;
956 * We keep the ref on mmo->obj, not vm_file, but we require
957 * vma->vm_file->f_mapping, see vma_link(), for later revocation.
958 * Our userspace is accustomed to having per-file resource cleanup
959 * (i.e. contexts, objects and requests) on their close(fd), which
960 * requires avoiding extraneous references to their filp, hence why
961 * we prefer to use an anonymous file for their mmaps.
963 vma_set_file(vma, anon);
964 /* Drop the initial creation reference, the vma is now holding one. */
967 if (obj->ops->mmap_ops) {
968 vma->vm_page_prot = pgprot_decrypted(vm_get_page_prot(vma->vm_flags));
969 vma->vm_ops = obj->ops->mmap_ops;
970 vma->vm_private_data = node->driver_private;
974 vma->vm_private_data = mmo;
976 switch (mmo->mmap_type) {
977 case I915_MMAP_TYPE_WC:
979 pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
980 vma->vm_ops = &vm_ops_cpu;
983 case I915_MMAP_TYPE_FIXED:
986 case I915_MMAP_TYPE_WB:
987 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
988 vma->vm_ops = &vm_ops_cpu;
991 case I915_MMAP_TYPE_UC:
993 pgprot_noncached(vm_get_page_prot(vma->vm_flags));
994 vma->vm_ops = &vm_ops_cpu;
997 case I915_MMAP_TYPE_GTT:
999 pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
1000 vma->vm_ops = &vm_ops_gtt;
1003 vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
1008 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
1009 #include "selftests/i915_gem_mman.c"