diff options
Diffstat (limited to 'drivers/gpu/drm/i915/gem/i915_gem_userptr.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 833 |
1 files changed, 833 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c new file mode 100644 index 000000000000..528b61678334 --- /dev/null +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -0,0 +1,833 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2012-2014 Intel Corporation + */ + +#include <linux/mmu_context.h> +#include <linux/mmu_notifier.h> +#include <linux/mempolicy.h> +#include <linux/swap.h> +#include <linux/sched/mm.h> + +#include <drm/i915_drm.h> + +#include "i915_gem_ioctls.h" +#include "i915_gem_object.h" +#include "i915_scatterlist.h" +#include "i915_trace.h" +#include "intel_drv.h" + +struct i915_mm_struct { + struct mm_struct *mm; + struct drm_i915_private *i915; + struct i915_mmu_notifier *mn; + struct hlist_node node; + struct kref kref; + struct work_struct work; +}; + +#if defined(CONFIG_MMU_NOTIFIER) +#include <linux/interval_tree.h> + +struct i915_mmu_notifier { + spinlock_t lock; + struct hlist_node node; + struct mmu_notifier mn; + struct rb_root_cached objects; + struct i915_mm_struct *mm; +}; + +struct i915_mmu_object { + struct i915_mmu_notifier *mn; + struct drm_i915_gem_object *obj; + struct interval_tree_node it; +}; + +static void add_object(struct i915_mmu_object *mo) +{ + GEM_BUG_ON(!RB_EMPTY_NODE(&mo->it.rb)); + interval_tree_insert(&mo->it, &mo->mn->objects); +} + +static void del_object(struct i915_mmu_object *mo) +{ + if (RB_EMPTY_NODE(&mo->it.rb)) + return; + + interval_tree_remove(&mo->it, &mo->mn->objects); + RB_CLEAR_NODE(&mo->it.rb); +} + +static void +__i915_gem_userptr_set_active(struct drm_i915_gem_object *obj, bool value) +{ + struct i915_mmu_object *mo = obj->userptr.mmu_object; + + /* + * During mm_invalidate_range we need to cancel any userptr that + * overlaps the range being invalidated. Doing so requires the + * struct_mutex, and that risks recursion. In order to cause + * recursion, the user must alias the userptr address space with + * a GTT mmapping (possible with a MAP_FIXED) - then when we have + * to invalidate that mmaping, mm_invalidate_range is called with + * the userptr address *and* the struct_mutex held. To prevent that + * we set a flag under the i915_mmu_notifier spinlock to indicate + * whether this object is valid. + */ + if (!mo) + return; + + spin_lock(&mo->mn->lock); + if (value) + add_object(mo); + else + del_object(mo); + spin_unlock(&mo->mn->lock); +} + +static int +userptr_mn_invalidate_range_start(struct mmu_notifier *_mn, + const struct mmu_notifier_range *range) +{ + struct i915_mmu_notifier *mn = + container_of(_mn, struct i915_mmu_notifier, mn); + struct interval_tree_node *it; + struct mutex *unlock = NULL; + unsigned long end; + int ret = 0; + + if (RB_EMPTY_ROOT(&mn->objects.rb_root)) + return 0; + + /* interval ranges are inclusive, but invalidate range is exclusive */ + end = range->end - 1; + + spin_lock(&mn->lock); + it = interval_tree_iter_first(&mn->objects, range->start, end); + while (it) { + struct drm_i915_gem_object *obj; + + if (!mmu_notifier_range_blockable(range)) { + ret = -EAGAIN; + break; + } + + /* + * The mmu_object is released late when destroying the + * GEM object so it is entirely possible to gain a + * reference on an object in the process of being freed + * since our serialisation is via the spinlock and not + * the struct_mutex - and consequently use it after it + * is freed and then double free it. To prevent that + * use-after-free we only acquire a reference on the + * object if it is not in the process of being destroyed. + */ + obj = container_of(it, struct i915_mmu_object, it)->obj; + if (!kref_get_unless_zero(&obj->base.refcount)) { + it = interval_tree_iter_next(it, range->start, end); + continue; + } + spin_unlock(&mn->lock); + + if (!unlock) { + unlock = &mn->mm->i915->drm.struct_mutex; + + switch (mutex_trylock_recursive(unlock)) { + default: + case MUTEX_TRYLOCK_FAILED: + if (mutex_lock_killable_nested(unlock, I915_MM_SHRINKER)) { + i915_gem_object_put(obj); + return -EINTR; + } + /* fall through */ + case MUTEX_TRYLOCK_SUCCESS: + break; + + case MUTEX_TRYLOCK_RECURSIVE: + unlock = ERR_PTR(-EEXIST); + break; + } + } + + ret = i915_gem_object_unbind(obj); + if (ret == 0) + ret = __i915_gem_object_put_pages(obj, I915_MM_SHRINKER); + i915_gem_object_put(obj); + if (ret) + goto unlock; + + spin_lock(&mn->lock); + + /* + * As we do not (yet) protect the mmu from concurrent insertion + * over this range, there is no guarantee that this search will + * terminate given a pathologic workload. + */ + it = interval_tree_iter_first(&mn->objects, range->start, end); + } + spin_unlock(&mn->lock); + +unlock: + if (!IS_ERR_OR_NULL(unlock)) + mutex_unlock(unlock); + + return ret; + +} + +static const struct mmu_notifier_ops i915_gem_userptr_notifier = { + .invalidate_range_start = userptr_mn_invalidate_range_start, +}; + +static struct i915_mmu_notifier * +i915_mmu_notifier_create(struct i915_mm_struct *mm) +{ + struct i915_mmu_notifier *mn; + + mn = kmalloc(sizeof(*mn), GFP_KERNEL); + if (mn == NULL) + return ERR_PTR(-ENOMEM); + + spin_lock_init(&mn->lock); + mn->mn.ops = &i915_gem_userptr_notifier; + mn->objects = RB_ROOT_CACHED; + mn->mm = mm; + + return mn; +} + +static void +i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj) +{ + struct i915_mmu_object *mo; + + mo = fetch_and_zero(&obj->userptr.mmu_object); + if (!mo) + return; + + spin_lock(&mo->mn->lock); + del_object(mo); + spin_unlock(&mo->mn->lock); + kfree(mo); +} + +static struct i915_mmu_notifier * +i915_mmu_notifier_find(struct i915_mm_struct *mm) +{ + struct i915_mmu_notifier *mn; + int err = 0; + + mn = mm->mn; + if (mn) + return mn; + + mn = i915_mmu_notifier_create(mm); + if (IS_ERR(mn)) + err = PTR_ERR(mn); + + down_write(&mm->mm->mmap_sem); + mutex_lock(&mm->i915->mm_lock); + if (mm->mn == NULL && !err) { + /* Protected by mmap_sem (write-lock) */ + err = __mmu_notifier_register(&mn->mn, mm->mm); + if (!err) { + /* Protected by mm_lock */ + mm->mn = fetch_and_zero(&mn); + } + } else if (mm->mn) { + /* + * Someone else raced and successfully installed the mmu + * notifier, we can cancel our own errors. + */ + err = 0; + } + mutex_unlock(&mm->i915->mm_lock); + up_write(&mm->mm->mmap_sem); + + if (mn && !IS_ERR(mn)) + kfree(mn); + + return err ? ERR_PTR(err) : mm->mn; +} + +static int +i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj, + unsigned flags) +{ + struct i915_mmu_notifier *mn; + struct i915_mmu_object *mo; + + if (flags & I915_USERPTR_UNSYNCHRONIZED) + return capable(CAP_SYS_ADMIN) ? 0 : -EPERM; + + if (WARN_ON(obj->userptr.mm == NULL)) + return -EINVAL; + + mn = i915_mmu_notifier_find(obj->userptr.mm); + if (IS_ERR(mn)) + return PTR_ERR(mn); + + mo = kzalloc(sizeof(*mo), GFP_KERNEL); + if (!mo) + return -ENOMEM; + + mo->mn = mn; + mo->obj = obj; + mo->it.start = obj->userptr.ptr; + mo->it.last = obj->userptr.ptr + obj->base.size - 1; + RB_CLEAR_NODE(&mo->it.rb); + + obj->userptr.mmu_object = mo; + return 0; +} + +static void +i915_mmu_notifier_free(struct i915_mmu_notifier *mn, + struct mm_struct *mm) +{ + if (mn == NULL) + return; + + mmu_notifier_unregister(&mn->mn, mm); + kfree(mn); +} + +#else + +static void +__i915_gem_userptr_set_active(struct drm_i915_gem_object *obj, bool value) +{ +} + +static void +i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj) +{ +} + +static int +i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj, + unsigned flags) +{ + if ((flags & I915_USERPTR_UNSYNCHRONIZED) == 0) + return -ENODEV; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + return 0; +} + +static void +i915_mmu_notifier_free(struct i915_mmu_notifier *mn, + struct mm_struct *mm) +{ +} + +#endif + +static struct i915_mm_struct * +__i915_mm_struct_find(struct drm_i915_private *dev_priv, struct mm_struct *real) +{ + struct i915_mm_struct *mm; + + /* Protected by dev_priv->mm_lock */ + hash_for_each_possible(dev_priv->mm_structs, mm, node, (unsigned long)real) + if (mm->mm == real) + return mm; + + return NULL; +} + +static int +i915_gem_userptr_init__mm_struct(struct drm_i915_gem_object *obj) +{ + struct drm_i915_private *dev_priv = to_i915(obj->base.dev); + struct i915_mm_struct *mm; + int ret = 0; + + /* During release of the GEM object we hold the struct_mutex. This + * precludes us from calling mmput() at that time as that may be + * the last reference and so call exit_mmap(). exit_mmap() will + * attempt to reap the vma, and if we were holding a GTT mmap + * would then call drm_gem_vm_close() and attempt to reacquire + * the struct mutex. So in order to avoid that recursion, we have + * to defer releasing the mm reference until after we drop the + * struct_mutex, i.e. we need to schedule a worker to do the clean + * up. + */ + mutex_lock(&dev_priv->mm_lock); + mm = __i915_mm_struct_find(dev_priv, current->mm); + if (mm == NULL) { + mm = kmalloc(sizeof(*mm), GFP_KERNEL); + if (mm == NULL) { + ret = -ENOMEM; + goto out; + } + + kref_init(&mm->kref); + mm->i915 = to_i915(obj->base.dev); + + mm->mm = current->mm; + mmgrab(current->mm); + + mm->mn = NULL; + + /* Protected by dev_priv->mm_lock */ + hash_add(dev_priv->mm_structs, + &mm->node, (unsigned long)mm->mm); + } else + kref_get(&mm->kref); + + obj->userptr.mm = mm; +out: + mutex_unlock(&dev_priv->mm_lock); + return ret; +} + +static void +__i915_mm_struct_free__worker(struct work_struct *work) +{ + struct i915_mm_struct *mm = container_of(work, typeof(*mm), work); + i915_mmu_notifier_free(mm->mn, mm->mm); + mmdrop(mm->mm); + kfree(mm); +} + +static void +__i915_mm_struct_free(struct kref *kref) +{ + struct i915_mm_struct *mm = container_of(kref, typeof(*mm), kref); + + /* Protected by dev_priv->mm_lock */ + hash_del(&mm->node); + mutex_unlock(&mm->i915->mm_lock); + + INIT_WORK(&mm->work, __i915_mm_struct_free__worker); + queue_work(mm->i915->mm.userptr_wq, &mm->work); +} + +static void +i915_gem_userptr_release__mm_struct(struct drm_i915_gem_object *obj) +{ + if (obj->userptr.mm == NULL) + return; + + kref_put_mutex(&obj->userptr.mm->kref, + __i915_mm_struct_free, + &to_i915(obj->base.dev)->mm_lock); + obj->userptr.mm = NULL; +} + +struct get_pages_work { + struct work_struct work; + struct drm_i915_gem_object *obj; + struct task_struct *task; +}; + +static struct sg_table * +__i915_gem_userptr_alloc_pages(struct drm_i915_gem_object *obj, + struct page **pvec, int num_pages) +{ + unsigned int max_segment = i915_sg_segment_size(); + struct sg_table *st; + unsigned int sg_page_sizes; + int ret; + + st = kmalloc(sizeof(*st), GFP_KERNEL); + if (!st) + return ERR_PTR(-ENOMEM); + +alloc_table: + ret = __sg_alloc_table_from_pages(st, pvec, num_pages, + 0, num_pages << PAGE_SHIFT, + max_segment, + GFP_KERNEL); + if (ret) { + kfree(st); + return ERR_PTR(ret); + } + + ret = i915_gem_gtt_prepare_pages(obj, st); + if (ret) { + sg_free_table(st); + + if (max_segment > PAGE_SIZE) { + max_segment = PAGE_SIZE; + goto alloc_table; + } + + kfree(st); + return ERR_PTR(ret); + } + + sg_page_sizes = i915_sg_page_sizes(st->sgl); + + __i915_gem_object_set_pages(obj, st, sg_page_sizes); + + return st; +} + +static void +__i915_gem_userptr_get_pages_worker(struct work_struct *_work) +{ + struct get_pages_work *work = container_of(_work, typeof(*work), work); + struct drm_i915_gem_object *obj = work->obj; + const int npages = obj->base.size >> PAGE_SHIFT; + struct page **pvec; + int pinned, ret; + + ret = -ENOMEM; + pinned = 0; + + pvec = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); + if (pvec != NULL) { + struct mm_struct *mm = obj->userptr.mm->mm; + unsigned int flags = 0; + + if (!i915_gem_object_is_readonly(obj)) + flags |= FOLL_WRITE; + + ret = -EFAULT; + if (mmget_not_zero(mm)) { + down_read(&mm->mmap_sem); + while (pinned < npages) { + ret = get_user_pages_remote + (work->task, mm, + obj->userptr.ptr + pinned * PAGE_SIZE, + npages - pinned, + flags, + pvec + pinned, NULL, NULL); + if (ret < 0) + break; + + pinned += ret; + } + up_read(&mm->mmap_sem); + mmput(mm); + } + } + + mutex_lock(&obj->mm.lock); + if (obj->userptr.work == &work->work) { + struct sg_table *pages = ERR_PTR(ret); + + if (pinned == npages) { + pages = __i915_gem_userptr_alloc_pages(obj, pvec, + npages); + if (!IS_ERR(pages)) { + pinned = 0; + pages = NULL; + } + } + + obj->userptr.work = ERR_CAST(pages); + if (IS_ERR(pages)) + __i915_gem_userptr_set_active(obj, false); + } + mutex_unlock(&obj->mm.lock); + + release_pages(pvec, pinned); + kvfree(pvec); + + i915_gem_object_put(obj); + put_task_struct(work->task); + kfree(work); +} + +static struct sg_table * +__i915_gem_userptr_get_pages_schedule(struct drm_i915_gem_object *obj) +{ + struct get_pages_work *work; + + /* Spawn a worker so that we can acquire the + * user pages without holding our mutex. Access + * to the user pages requires mmap_sem, and we have + * a strict lock ordering of mmap_sem, struct_mutex - + * we already hold struct_mutex here and so cannot + * call gup without encountering a lock inversion. + * + * Userspace will keep on repeating the operation + * (thanks to EAGAIN) until either we hit the fast + * path or the worker completes. If the worker is + * cancelled or superseded, the task is still run + * but the results ignored. (This leads to + * complications that we may have a stray object + * refcount that we need to be wary of when + * checking for existing objects during creation.) + * If the worker encounters an error, it reports + * that error back to this function through + * obj->userptr.work = ERR_PTR. + */ + work = kmalloc(sizeof(*work), GFP_KERNEL); + if (work == NULL) + return ERR_PTR(-ENOMEM); + + obj->userptr.work = &work->work; + + work->obj = i915_gem_object_get(obj); + + work->task = current; + get_task_struct(work->task); + + INIT_WORK(&work->work, __i915_gem_userptr_get_pages_worker); + queue_work(to_i915(obj->base.dev)->mm.userptr_wq, &work->work); + + return ERR_PTR(-EAGAIN); +} + +static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj) +{ + const int num_pages = obj->base.size >> PAGE_SHIFT; + struct mm_struct *mm = obj->userptr.mm->mm; + struct page **pvec; + struct sg_table *pages; + bool active; + int pinned; + + /* If userspace should engineer that these pages are replaced in + * the vma between us binding this page into the GTT and completion + * of rendering... Their loss. If they change the mapping of their + * pages they need to create a new bo to point to the new vma. + * + * However, that still leaves open the possibility of the vma + * being copied upon fork. Which falls under the same userspace + * synchronisation issue as a regular bo, except that this time + * the process may not be expecting that a particular piece of + * memory is tied to the GPU. + * + * Fortunately, we can hook into the mmu_notifier in order to + * discard the page references prior to anything nasty happening + * to the vma (discard or cloning) which should prevent the more + * egregious cases from causing harm. + */ + + if (obj->userptr.work) { + /* active flag should still be held for the pending work */ + if (IS_ERR(obj->userptr.work)) + return PTR_ERR(obj->userptr.work); + else + return -EAGAIN; + } + + pvec = NULL; + pinned = 0; + + if (mm == current->mm) { + pvec = kvmalloc_array(num_pages, sizeof(struct page *), + GFP_KERNEL | + __GFP_NORETRY | + __GFP_NOWARN); + if (pvec) /* defer to worker if malloc fails */ + pinned = __get_user_pages_fast(obj->userptr.ptr, + num_pages, + !i915_gem_object_is_readonly(obj), + pvec); + } + + active = false; + if (pinned < 0) { + pages = ERR_PTR(pinned); + pinned = 0; + } else if (pinned < num_pages) { + pages = __i915_gem_userptr_get_pages_schedule(obj); + active = pages == ERR_PTR(-EAGAIN); + } else { + pages = __i915_gem_userptr_alloc_pages(obj, pvec, num_pages); + active = !IS_ERR(pages); + } + if (active) + __i915_gem_userptr_set_active(obj, true); + + if (IS_ERR(pages)) + release_pages(pvec, pinned); + kvfree(pvec); + + return PTR_ERR_OR_ZERO(pages); +} + +static void +i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj, + struct sg_table *pages) +{ + struct sgt_iter sgt_iter; + struct page *page; + + /* Cancel any inflight work and force them to restart their gup */ + obj->userptr.work = NULL; + __i915_gem_userptr_set_active(obj, false); + if (!pages) + return; + + __i915_gem_object_release_shmem(obj, pages, true); + i915_gem_gtt_finish_pages(obj, pages); + + for_each_sgt_page(page, sgt_iter, pages) { + if (obj->mm.dirty) + set_page_dirty(page); + + mark_page_accessed(page); + put_page(page); + } + obj->mm.dirty = false; + + sg_free_table(pages); + kfree(pages); +} + +static void +i915_gem_userptr_release(struct drm_i915_gem_object *obj) +{ + i915_gem_userptr_release__mmu_notifier(obj); + i915_gem_userptr_release__mm_struct(obj); +} + +static int +i915_gem_userptr_dmabuf_export(struct drm_i915_gem_object *obj) +{ + if (obj->userptr.mmu_object) + return 0; + + return i915_gem_userptr_init__mmu_notifier(obj, 0); +} + +static const struct drm_i915_gem_object_ops i915_gem_userptr_ops = { + .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE | + I915_GEM_OBJECT_IS_SHRINKABLE | + I915_GEM_OBJECT_ASYNC_CANCEL, + .get_pages = i915_gem_userptr_get_pages, + .put_pages = i915_gem_userptr_put_pages, + .dmabuf_export = i915_gem_userptr_dmabuf_export, + .release = i915_gem_userptr_release, +}; + +/* + * Creates a new mm object that wraps some normal memory from the process + * context - user memory. + * + * We impose several restrictions upon the memory being mapped + * into the GPU. + * 1. It must be page aligned (both start/end addresses, i.e ptr and size). + * 2. It must be normal system memory, not a pointer into another map of IO + * space (e.g. it must not be a GTT mmapping of another object). + * 3. We only allow a bo as large as we could in theory map into the GTT, + * that is we limit the size to the total size of the GTT. + * 4. The bo is marked as being snoopable. The backing pages are left + * accessible directly by the CPU, but reads and writes by the GPU may + * incur the cost of a snoop (unless you have an LLC architecture). + * + * Synchronisation between multiple users and the GPU is left to userspace + * through the normal set-domain-ioctl. The kernel will enforce that the + * GPU relinquishes the VMA before it is returned back to the system + * i.e. upon free(), munmap() or process termination. However, the userspace + * malloc() library may not immediately relinquish the VMA after free() and + * instead reuse it whilst the GPU is still reading and writing to the VMA. + * Caveat emptor. + * + * Also note, that the object created here is not currently a "first class" + * object, in that several ioctls are banned. These are the CPU access + * ioctls: mmap(), pwrite and pread. In practice, you are expected to use + * direct access via your pointer rather than use those ioctls. Another + * restriction is that we do not allow userptr surfaces to be pinned to the + * hardware and so we reject any attempt to create a framebuffer out of a + * userptr. + * + * If you think this is a good interface to use to pass GPU memory between + * drivers, please use dma-buf instead. In fact, wherever possible use + * dma-buf instead. + */ +int +i915_gem_userptr_ioctl(struct drm_device *dev, + void *data, + struct drm_file *file) +{ + struct drm_i915_private *dev_priv = to_i915(dev); + struct drm_i915_gem_userptr *args = data; + struct drm_i915_gem_object *obj; + int ret; + u32 handle; + + if (!HAS_LLC(dev_priv) && !HAS_SNOOP(dev_priv)) { + /* We cannot support coherent userptr objects on hw without + * LLC and broken snooping. + */ + return -ENODEV; + } + + if (args->flags & ~(I915_USERPTR_READ_ONLY | + I915_USERPTR_UNSYNCHRONIZED)) + return -EINVAL; + + if (!args->user_size) + return -EINVAL; + + if (offset_in_page(args->user_ptr | args->user_size)) + return -EINVAL; + + if (!access_ok((char __user *)(unsigned long)args->user_ptr, args->user_size)) + return -EFAULT; + + if (args->flags & I915_USERPTR_READ_ONLY) { + struct i915_address_space *vm; + + /* + * On almost all of the older hw, we cannot tell the GPU that + * a page is readonly. + */ + vm = dev_priv->kernel_context->vm; + if (!vm || !vm->has_read_only) + return -ENODEV; + } + + obj = i915_gem_object_alloc(); + if (obj == NULL) + return -ENOMEM; + + drm_gem_private_object_init(dev, &obj->base, args->user_size); + i915_gem_object_init(obj, &i915_gem_userptr_ops); + obj->read_domains = I915_GEM_DOMAIN_CPU; + obj->write_domain = I915_GEM_DOMAIN_CPU; + i915_gem_object_set_cache_coherency(obj, I915_CACHE_LLC); + + obj->userptr.ptr = args->user_ptr; + if (args->flags & I915_USERPTR_READ_ONLY) + i915_gem_object_set_readonly(obj); + + /* And keep a pointer to the current->mm for resolving the user pages + * at binding. This means that we need to hook into the mmu_notifier + * in order to detect if the mmu is destroyed. + */ + ret = i915_gem_userptr_init__mm_struct(obj); + if (ret == 0) + ret = i915_gem_userptr_init__mmu_notifier(obj, args->flags); + if (ret == 0) + ret = drm_gem_handle_create(file, &obj->base, &handle); + + /* drop reference from allocate - handle holds it now */ + i915_gem_object_put(obj); + if (ret) + return ret; + + args->handle = handle; + return 0; +} + +int i915_gem_init_userptr(struct drm_i915_private *dev_priv) +{ + mutex_init(&dev_priv->mm_lock); + hash_init(dev_priv->mm_structs); + + dev_priv->mm.userptr_wq = + alloc_workqueue("i915-userptr-acquire", + WQ_HIGHPRI | WQ_UNBOUND, + 0); + if (!dev_priv->mm.userptr_wq) + return -ENOMEM; + + return 0; +} + +void i915_gem_cleanup_userptr(struct drm_i915_private *dev_priv) +{ + destroy_workqueue(dev_priv->mm.userptr_wq); +} |