[PATCH] i915: purify user ptr ioctl through the fire of truth.

j.glisse at gmail.com j.glisse at gmail.com
Mon Jun 30 11:23:32 PDT 2014


From: Jerome Glisse <jglisse at redhat.com>

Heresy should not be tolerated, any ioctl that rely on pure luck
should die. Violating memory pining kernel policy and all the
reasonable expection kernel have about user of mmu_notifier api
is not tolerable.

Because we can neither broke old userspace the ioctl is left but
i will never succeed which is the only reliable option for it.

Signed-off-by: Jérôme Glisse <jglisse at redhat.com>
---
 drivers/gpu/drm/i915/i915_drv.h         |  15 -
 drivers/gpu/drm/i915/i915_gem.c         |   1 -
 drivers/gpu/drm/i915/i915_gem_userptr.c | 687 +-------------------------------
 drivers/gpu/drm/i915/i915_gpu_error.c   |   2 -
 4 files changed, 5 insertions(+), 700 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 8cea596..3970bd0 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -393,7 +393,6 @@ struct drm_i915_error_state {
 		u32 tiling:2;
 		u32 dirty:1;
 		u32 purgeable:1;
-		u32 userptr:1;
 		s32 ring:4;
 		u32 cache_level:3;
 	} **active_bo, **pinned_bo;
@@ -1750,19 +1749,6 @@ struct drm_i915_gem_object {
 
 	/** for phy allocated objects */
 	drm_dma_handle_t *phys_handle;
-
-	union {
-		struct i915_gem_userptr {
-			uintptr_t ptr;
-			unsigned read_only :1;
-			unsigned workers :4;
-#define I915_GEM_USERPTR_MAX_WORKERS 15
-
-			struct mm_struct *mm;
-			struct i915_mmu_object *mn;
-			struct work_struct *work;
-		} userptr;
-	};
 };
 #define to_intel_bo(x) container_of(x, struct drm_i915_gem_object, base)
 
@@ -2195,7 +2181,6 @@ int i915_gem_set_tiling(struct drm_device *dev, void *data,
 			struct drm_file *file_priv);
 int i915_gem_get_tiling(struct drm_device *dev, void *data,
 			struct drm_file *file_priv);
-int i915_gem_init_userptr(struct drm_device *dev);
 int i915_gem_userptr_ioctl(struct drm_device *dev, void *data,
 			   struct drm_file *file);
 int i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f6d1238..30fc784 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4754,7 +4754,6 @@ int i915_gem_init(struct drm_device *dev)
 			DRM_DEBUG_DRIVER("allow wake ack timed out\n");
 	}
 
-	i915_gem_init_userptr(dev);
 	i915_gem_init_global_gtt(dev);
 
 	ret = i915_gem_context_init(dev);
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 191ac71..f261cb9 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -22,692 +22,15 @@
  *
  */
 
-#include "drmP.h"
 #include "i915_drm.h"
 #include "i915_drv.h"
-#include "i915_trace.h"
 #include "intel_drv.h"
-#include <linux/mmu_context.h>
-#include <linux/mmu_notifier.h>
-#include <linux/mempolicy.h>
-#include <linux/swap.h>
 
-#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 objects;
-	struct drm_device *dev;
-	struct mm_struct *mm;
-	struct work_struct work;
-	unsigned long count;
-	unsigned long serial;
-};
-
-struct i915_mmu_object {
-	struct i915_mmu_notifier *mmu;
-	struct interval_tree_node it;
-	struct drm_i915_gem_object *obj;
-};
-
-static void i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn,
-						       struct mm_struct *mm,
-						       struct vm_area_struct *vma,
-						       unsigned long start,
-						       unsigned long end,
-						       enum mmu_event event)
-{
-	struct i915_mmu_notifier *mn = container_of(_mn, struct i915_mmu_notifier, mn);
-	struct interval_tree_node *it = NULL;
-	unsigned long serial = 0;
-
-	end--; /* interval ranges are inclusive, but invalidate range is exclusive */
-	while (start < end) {
-		struct drm_i915_gem_object *obj;
-
-		obj = NULL;
-		spin_lock(&mn->lock);
-		if (serial == mn->serial)
-			it = interval_tree_iter_next(it, start, end);
-		else
-			it = interval_tree_iter_first(&mn->objects, start, end);
-		if (it != NULL) {
-			obj = container_of(it, struct i915_mmu_object, it)->obj;
-			drm_gem_object_reference(&obj->base);
-			serial = mn->serial;
-		}
-		spin_unlock(&mn->lock);
-		if (obj == NULL)
-			return;
-
-		mutex_lock(&mn->dev->struct_mutex);
-		/* Cancel any active worker and force us to re-evaluate gup */
-		obj->userptr.work = NULL;
-
-		if (obj->pages != NULL) {
-			struct drm_i915_private *dev_priv = to_i915(mn->dev);
-			struct i915_vma *vma, *tmp;
-			bool was_interruptible;
-
-			was_interruptible = dev_priv->mm.interruptible;
-			dev_priv->mm.interruptible = false;
-
-			list_for_each_entry_safe(vma, tmp, &obj->vma_list, vma_link) {
-				int ret = i915_vma_unbind(vma);
-				WARN_ON(ret && ret != -EIO);
-			}
-			WARN_ON(i915_gem_object_put_pages(obj));
-
-			dev_priv->mm.interruptible = was_interruptible;
-		}
-
-		start = obj->userptr.ptr + obj->base.size;
-
-		drm_gem_object_unreference(&obj->base);
-		mutex_unlock(&mn->dev->struct_mutex);
-	}
-}
-
-static const struct mmu_notifier_ops i915_gem_userptr_notifier = {
-	.invalidate_range_start = i915_gem_userptr_mn_invalidate_range_start,
-};
-
-static struct i915_mmu_notifier *
-__i915_mmu_notifier_lookup(struct drm_device *dev, struct mm_struct *mm)
-{
-	struct drm_i915_private *dev_priv = to_i915(dev);
-	struct i915_mmu_notifier *mmu;
-
-	/* Protected by dev->struct_mutex */
-	hash_for_each_possible(dev_priv->mmu_notifiers, mmu, node, (unsigned long)mm)
-		if (mmu->mm == mm)
-			return mmu;
-
-	return NULL;
-}
-
-static struct i915_mmu_notifier *
-i915_mmu_notifier_get(struct drm_device *dev, struct mm_struct *mm)
-{
-	struct drm_i915_private *dev_priv = to_i915(dev);
-	struct i915_mmu_notifier *mmu;
-	int ret;
-
-	lockdep_assert_held(&dev->struct_mutex);
-
-	mmu = __i915_mmu_notifier_lookup(dev, mm);
-	if (mmu)
-		return mmu;
-
-	mmu = kmalloc(sizeof(*mmu), GFP_KERNEL);
-	if (mmu == NULL)
-		return ERR_PTR(-ENOMEM);
-
-	spin_lock_init(&mmu->lock);
-	mmu->dev = dev;
-	mmu->mn.ops = &i915_gem_userptr_notifier;
-	mmu->mm = mm;
-	mmu->objects = RB_ROOT;
-	mmu->count = 0;
-	mmu->serial = 0;
-
-	/* Protected by mmap_sem (write-lock) */
-	ret = __mmu_notifier_register(&mmu->mn, mm);
-	if (ret) {
-		kfree(mmu);
-		return ERR_PTR(ret);
-	}
-
-	/* Protected by dev->struct_mutex */
-	hash_add(dev_priv->mmu_notifiers, &mmu->node, (unsigned long)mm);
-	return mmu;
-}
-
-static void
-__i915_mmu_notifier_destroy_worker(struct work_struct *work)
-{
-	struct i915_mmu_notifier *mmu = container_of(work, typeof(*mmu), work);
-	mmu_notifier_unregister(&mmu->mn, mmu->mm);
-	kfree(mmu);
-}
-
-static void
-__i915_mmu_notifier_destroy(struct i915_mmu_notifier *mmu)
-{
-	lockdep_assert_held(&mmu->dev->struct_mutex);
-
-	/* Protected by dev->struct_mutex */
-	hash_del(&mmu->node);
-
-	/* Our lock ordering is: mmap_sem, mmu_notifier_scru, struct_mutex.
-	 * We enter the function holding struct_mutex, therefore we need
-	 * to drop our mutex prior to calling mmu_notifier_unregister in
-	 * order to prevent lock inversion (and system-wide deadlock)
-	 * between the mmap_sem and struct-mutex. Hence we defer the
-	 * unregistration to a workqueue where we hold no locks.
-	 */
-	INIT_WORK(&mmu->work, __i915_mmu_notifier_destroy_worker);
-	schedule_work(&mmu->work);
-}
-
-static void __i915_mmu_notifier_update_serial(struct i915_mmu_notifier *mmu)
-{
-	if (++mmu->serial == 0)
-		mmu->serial = 1;
-}
-
-static void
-i915_mmu_notifier_del(struct i915_mmu_notifier *mmu,
-		      struct i915_mmu_object *mn)
-{
-	lockdep_assert_held(&mmu->dev->struct_mutex);
-
-	spin_lock(&mmu->lock);
-	interval_tree_remove(&mn->it, &mmu->objects);
-	__i915_mmu_notifier_update_serial(mmu);
-	spin_unlock(&mmu->lock);
-
-	/* Protected against _add() by dev->struct_mutex */
-	if (--mmu->count == 0)
-		__i915_mmu_notifier_destroy(mmu);
-}
-
-static int
-i915_mmu_notifier_add(struct i915_mmu_notifier *mmu,
-		      struct i915_mmu_object *mn)
-{
-	struct interval_tree_node *it;
-	int ret;
-
-	ret = i915_mutex_lock_interruptible(mmu->dev);
-	if (ret)
-		return ret;
-
-	/* Make sure we drop the final active reference (and thereby
-	 * remove the objects from the interval tree) before we do
-	 * the check for overlapping objects.
-	 */
-	i915_gem_retire_requests(mmu->dev);
-
-	/* Disallow overlapping userptr objects */
-	spin_lock(&mmu->lock);
-	it = interval_tree_iter_first(&mmu->objects,
-				      mn->it.start, mn->it.last);
-	if (it) {
-		struct drm_i915_gem_object *obj;
-
-		/* We only need to check the first object in the range as it
-		 * either has cancelled gup work queued and we need to
-		 * return back to the user to give time for the gup-workers
-		 * to flush their object references upon which the object will
-		 * be removed from the interval-tree, or the the range is
-		 * still in use by another client and the overlap is invalid.
-		 */
-
-		obj = container_of(it, struct i915_mmu_object, it)->obj;
-		ret = obj->userptr.workers ? -EAGAIN : -EINVAL;
-	} else {
-		interval_tree_insert(&mn->it, &mmu->objects);
-		__i915_mmu_notifier_update_serial(mmu);
-		ret = 0;
-	}
-	spin_unlock(&mmu->lock);
-	mutex_unlock(&mmu->dev->struct_mutex);
-
-	return ret;
-}
-
-static void
-i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj)
-{
-	struct i915_mmu_object *mn;
-
-	mn = obj->userptr.mn;
-	if (mn == NULL)
-		return;
-
-	i915_mmu_notifier_del(mn->mmu, mn);
-	obj->userptr.mn = NULL;
-}
-
-static int
-i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj,
-				    unsigned flags)
-{
-	struct i915_mmu_notifier *mmu;
-	struct i915_mmu_object *mn;
-	int ret;
-
-	if (flags & I915_USERPTR_UNSYNCHRONIZED)
-		return capable(CAP_SYS_ADMIN) ? 0 : -EPERM;
-
-	down_write(&obj->userptr.mm->mmap_sem);
-	ret = i915_mutex_lock_interruptible(obj->base.dev);
-	if (ret == 0) {
-		mmu = i915_mmu_notifier_get(obj->base.dev, obj->userptr.mm);
-		if (!IS_ERR(mmu))
-			mmu->count++; /* preemptive add to act as a refcount */
-		else
-			ret = PTR_ERR(mmu);
-		mutex_unlock(&obj->base.dev->struct_mutex);
-	}
-	up_write(&obj->userptr.mm->mmap_sem);
-	if (ret)
-		return ret;
-
-	mn = kzalloc(sizeof(*mn), GFP_KERNEL);
-	if (mn == NULL) {
-		ret = -ENOMEM;
-		goto destroy_mmu;
-	}
-
-	mn->mmu = mmu;
-	mn->it.start = obj->userptr.ptr;
-	mn->it.last = mn->it.start + obj->base.size - 1;
-	mn->obj = obj;
-
-	ret = i915_mmu_notifier_add(mmu, mn);
-	if (ret)
-		goto free_mn;
-
-	obj->userptr.mn = mn;
-	return 0;
-
-free_mn:
-	kfree(mn);
-destroy_mmu:
-	mutex_lock(&obj->base.dev->struct_mutex);
-	if (--mmu->count == 0)
-		__i915_mmu_notifier_destroy(mmu);
-	mutex_unlock(&obj->base.dev->struct_mutex);
-	return ret;
-}
-
-#else
-
-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;
-}
-#endif
-
-struct get_pages_work {
-	struct work_struct work;
-	struct drm_i915_gem_object *obj;
-	struct task_struct *task;
-};
-
-
-#if IS_ENABLED(CONFIG_SWIOTLB)
-#define swiotlb_active() swiotlb_nr_tbl()
-#else
-#define swiotlb_active() 0
-#endif
-
-static int
-st_set_pages(struct sg_table **st, struct page **pvec, int num_pages)
-{
-	struct scatterlist *sg;
-	int ret, n;
-
-	*st = kmalloc(sizeof(**st), GFP_KERNEL);
-	if (*st == NULL)
-		return -ENOMEM;
-
-	if (swiotlb_active()) {
-		ret = sg_alloc_table(*st, num_pages, GFP_KERNEL);
-		if (ret)
-			goto err;
-
-		for_each_sg((*st)->sgl, sg, num_pages, n)
-			sg_set_page(sg, pvec[n], PAGE_SIZE, 0);
-	} else {
-		ret = sg_alloc_table_from_pages(*st, pvec, num_pages,
-						0, num_pages << PAGE_SHIFT,
-						GFP_KERNEL);
-		if (ret)
-			goto err;
-	}
-
-	return 0;
-
-err:
-	kfree(*st);
-	*st = NULL;
-	return ret;
-}
-
-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;
-	struct drm_device *dev = obj->base.dev;
-	const int num_pages = obj->base.size >> PAGE_SHIFT;
-	struct page **pvec;
-	int pinned, ret;
-
-	ret = -ENOMEM;
-	pinned = 0;
-
-	pvec = kmalloc(num_pages*sizeof(struct page *),
-		       GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
-	if (pvec == NULL)
-		pvec = drm_malloc_ab(num_pages, sizeof(struct page *));
-	if (pvec != NULL) {
-		struct mm_struct *mm = obj->userptr.mm;
-
-		down_read(&mm->mmap_sem);
-		while (pinned < num_pages) {
-			ret = get_user_pages(work->task, mm,
-					     obj->userptr.ptr + pinned * PAGE_SIZE,
-					     num_pages - pinned,
-					     !obj->userptr.read_only, 0,
-					     pvec + pinned, NULL);
-			if (ret < 0)
-				break;
-
-			pinned += ret;
-		}
-		up_read(&mm->mmap_sem);
-	}
-
-	mutex_lock(&dev->struct_mutex);
-	if (obj->userptr.work != &work->work) {
-		ret = 0;
-	} else if (pinned == num_pages) {
-		ret = st_set_pages(&obj->pages, pvec, num_pages);
-		if (ret == 0) {
-			list_add_tail(&obj->global_list, &to_i915(dev)->mm.unbound_list);
-			pinned = 0;
-		}
-	}
-
-	obj->userptr.work = ERR_PTR(ret);
-	obj->userptr.workers--;
-	drm_gem_object_unreference(&obj->base);
-	mutex_unlock(&dev->struct_mutex);
-
-	release_pages(pvec, pinned, 0);
-	drm_free_large(pvec);
-
-	put_task_struct(work->task);
-	kfree(work);
-}
-
-static int
-i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
-{
-	const int num_pages = obj->base.size >> PAGE_SHIFT;
-	struct page **pvec;
-	int pinned, ret;
-
-	/* 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.
-	 */
-
-	pvec = NULL;
-	pinned = 0;
-	if (obj->userptr.mm == current->mm) {
-		pvec = kmalloc(num_pages*sizeof(struct page *),
-			       GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
-		if (pvec == NULL) {
-			pvec = drm_malloc_ab(num_pages, sizeof(struct page *));
-			if (pvec == NULL)
-				return -ENOMEM;
-		}
-
-		pinned = __get_user_pages_fast(obj->userptr.ptr, num_pages,
-					       !obj->userptr.read_only, pvec);
-	}
-	if (pinned < num_pages) {
-		if (pinned < 0) {
-			ret = pinned;
-			pinned = 0;
-		} else {
-			/* 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.
-			 */
-			ret = -EAGAIN;
-			if (obj->userptr.work == NULL &&
-			    obj->userptr.workers < I915_GEM_USERPTR_MAX_WORKERS) {
-				struct get_pages_work *work;
-
-				work = kmalloc(sizeof(*work), GFP_KERNEL);
-				if (work != NULL) {
-					obj->userptr.work = &work->work;
-					obj->userptr.workers++;
-
-					work->obj = obj;
-					drm_gem_object_reference(&obj->base);
-
-					work->task = current;
-					get_task_struct(work->task);
-
-					INIT_WORK(&work->work, __i915_gem_userptr_get_pages_worker);
-					schedule_work(&work->work);
-				} else
-					ret = -ENOMEM;
-			} else {
-				if (IS_ERR(obj->userptr.work)) {
-					ret = PTR_ERR(obj->userptr.work);
-					obj->userptr.work = NULL;
-				}
-			}
-		}
-	} else {
-		ret = st_set_pages(&obj->pages, pvec, num_pages);
-		if (ret == 0) {
-			obj->userptr.work = NULL;
-			pinned = 0;
-		}
-	}
-
-	release_pages(pvec, pinned, 0);
-	drm_free_large(pvec);
-	return ret;
-}
-
-static void
-i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj)
-{
-	struct scatterlist *sg;
-	int i;
-
-	BUG_ON(obj->userptr.work != NULL);
-
-	if (obj->madv != I915_MADV_WILLNEED)
-		obj->dirty = 0;
-
-	for_each_sg(obj->pages->sgl, sg, obj->pages->nents, i) {
-		struct page *page = sg_page(sg);
-
-		if (obj->dirty)
-			set_page_dirty(page);
-
-		mark_page_accessed(page);
-		page_cache_release(page);
-	}
-	obj->dirty = 0;
-
-	sg_free_table(obj->pages);
-	kfree(obj->pages);
-}
-
-static void
-i915_gem_userptr_release(struct drm_i915_gem_object *obj)
-{
-	i915_gem_userptr_release__mmu_notifier(obj);
-
-	if (obj->userptr.mm) {
-		mmput(obj->userptr.mm);
-		obj->userptr.mm = NULL;
-	}
-}
-
-static int
-i915_gem_userptr_dmabuf_export(struct drm_i915_gem_object *obj)
-{
-	if (obj->userptr.mn)
-		return 0;
-
-	return i915_gem_userptr_init__mmu_notifier(obj, 0);
-}
-
-static const struct drm_i915_gem_object_ops i915_gem_userptr_ops = {
-	.dmabuf_export = i915_gem_userptr_dmabuf_export,
-	.get_pages = i915_gem_userptr_get_pages,
-	.put_pages = i915_gem_userptr_put_pages,
-	.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 cannot overlap any other userptr object in the same address space.
- * 3. 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).
- * 4. 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.
- * 5. 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.
- *
- * 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.
+/* This ioctl was deemed as an heresy and was purified in its only acceptable
+ * form.
  */
-int
-i915_gem_userptr_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct drm_i915_gem_userptr *args = data;
-	struct drm_i915_gem_object *obj;
-	int ret;
-	u32 handle;
-
-	if (args->flags & ~(I915_USERPTR_READ_ONLY |
-			    I915_USERPTR_UNSYNCHRONIZED))
-		return -EINVAL;
-
-	if (offset_in_page(args->user_ptr | args->user_size))
-		return -EINVAL;
-
-	if (args->user_size > dev_priv->gtt.base.total)
-		return -E2BIG;
-
-	if (!access_ok(args->flags & I915_USERPTR_READ_ONLY ? VERIFY_READ : VERIFY_WRITE,
-		       (char __user *)(unsigned long)args->user_ptr, args->user_size))
-		return -EFAULT;
-
-	if (args->flags & I915_USERPTR_READ_ONLY) {
-		/* On almost all of the current hw, we cannot tell the GPU that a
-		 * page is readonly, so this is just a placeholder in the uAPI.
-		 */
-		return -ENODEV;
-	}
-
-	/* Allocate the new object */
-	obj = i915_gem_object_alloc(dev);
-	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->cache_level = I915_CACHE_LLC;
-	obj->base.write_domain = I915_GEM_DOMAIN_CPU;
-	obj->base.read_domains = I915_GEM_DOMAIN_CPU;
-
-	obj->userptr.ptr = args->user_ptr;
-	obj->userptr.read_only = !!(args->flags & I915_USERPTR_READ_ONLY);
-
-	/* 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 = -ENOMEM;
-	if ((obj->userptr.mm = get_task_mm(current)))
-		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 */
-	drm_gem_object_unreference_unlocked(&obj->base);
-	if (ret)
-		return ret;
-
-	args->handle = handle;
-	return 0;
-}
-
-int
-i915_gem_init_userptr(struct drm_device *dev)
+int i915_gem_userptr_ioctl(struct drm_device *dev,
+			   void *data, struct drm_file *file)
 {
-#if defined(CONFIG_MMU_NOTIFIER)
-	struct drm_i915_private *dev_priv = to_i915(dev);
-	hash_init(dev_priv->mmu_notifiers);
-#endif
-	return 0;
+	return -EINVAL;
 }
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 66cf417..b94aab7 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -205,7 +205,6 @@ static void print_error_buffers(struct drm_i915_error_state_buf *m,
 		err_puts(m, tiling_flag(err->tiling));
 		err_puts(m, dirty_flag(err->dirty));
 		err_puts(m, purgeable_flag(err->purgeable));
-		err_puts(m, err->userptr ? " userptr" : "");
 		err_puts(m, err->ring != -1 ? " " : "");
 		err_puts(m, ring_str(err->ring));
 		err_puts(m, i915_cache_level_str(err->cache_level));
@@ -642,7 +641,6 @@ static void capture_bo(struct drm_i915_error_buffer *err,
 	err->tiling = obj->tiling_mode;
 	err->dirty = obj->dirty;
 	err->purgeable = obj->madv != I915_MADV_WILLNEED;
-	err->userptr = obj->userptr.mm != NULL;
 	err->ring = obj->ring ? obj->ring->id : -1;
 	err->cache_level = obj->cache_level;
 }
-- 
1.8.3.1



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