From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
The new API is an exact match for the needs of radeon.
For some reason radeon tries to remove overlapping ranges from the
interval tree, but interval trees (and mmu_interval_notifier_insert())
support overlapping ranges directly. Simply delete all this code.
Since this driver is missing a invalidate_range_end callback, but
still calls get_user_pages(), it cannot be correct against all races.
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
---
drivers/gpu/drm/radeon/radeon.h | 9 +-
drivers/gpu/drm/radeon/radeon_mn.c | 218 ++++++-----------------------
2 files changed, 51 insertions(+), 176 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index d59b004f669583..30e32adc1fc666 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -68,6 +68,10 @@
#include <linux/hashtable.h>
#include <linux/dma-fence.h>
+#ifdef CONFIG_MMU_NOTIFIER
+#include <linux/mmu_notifier.h>
+#endif
+
#include <drm/ttm/ttm_bo_api.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_placement.h>
@@ -509,8 +513,9 @@ struct radeon_bo {
struct ttm_bo_kmap_obj dma_buf_vmap;
pid_t pid;
- struct radeon_mn *mn;
- struct list_head mn_list;
+#ifdef CONFIG_MMU_NOTIFIER
+ struct mmu_interval_notifier notifier;
+#endif
};
#define gem_to_radeon_bo(gobj) container_of((gobj), struct radeon_bo, tbo.base)
diff --git a/drivers/gpu/drm/radeon/radeon_mn.c b/drivers/gpu/drm/radeon/radeon_mn.c
index dbab9a3a969b9e..f93829f08a4dc1 100644
--- a/drivers/gpu/drm/radeon/radeon_mn.c
+++ b/drivers/gpu/drm/radeon/radeon_mn.c
@@ -36,131 +36,51 @@
#include "radeon.h"
-struct radeon_mn {
- struct mmu_notifier mn;
-
- /* objects protected by lock */
- struct mutex lock;
- struct rb_root_cached objects;
-};
-
-struct radeon_mn_node {
- struct interval_tree_node it;
- struct list_head bos;
-};
-
/**
- * radeon_mn_invalidate_range_start - callback to notify about mm change
+ * radeon_mn_invalidate - callback to notify about mm change
*
* @mn: our notifier
- * @mn: the mm this callback is about
- * @start: start of updated range
- * @end: end of updated range
+ * @range: the VMA under invalidation
*
* We block for all BOs between start and end to be idle and
* unmap them by move them into system domain again.
*/
-static int radeon_mn_invalidate_range_start(struct mmu_notifier *mn,
- const struct mmu_notifier_range *range)
+static bool radeon_mn_invalidate(struct mmu_interval_notifier *mn,
+ const struct mmu_notifier_range *range,
+ unsigned long cur_seq)
{
- struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn);
+ struct radeon_bo *bo = container_of(mn, struct radeon_bo, notifier);
struct ttm_operation_ctx ctx = { false, false };
- struct interval_tree_node *it;
- unsigned long end;
- int ret = 0;
-
- /* notification is exclusive, but interval is inclusive */
- end = range->end - 1;
-
- /* TODO we should be able to split locking for interval tree and
- * the tear down.
- */
- if (mmu_notifier_range_blockable(range))
- mutex_lock(&rmn->lock);
- else if (!mutex_trylock(&rmn->lock))
- return -EAGAIN;
-
- it = interval_tree_iter_first(&rmn->objects, range->start, end);
- while (it) {
- struct radeon_mn_node *node;
- struct radeon_bo *bo;
- long r;
-
- if (!mmu_notifier_range_blockable(range)) {
- ret = -EAGAIN;
- goto out_unlock;
- }
-
- node = container_of(it, struct radeon_mn_node, it);
- it = interval_tree_iter_next(it, range->start, end);
+ long r;
- list_for_each_entry(bo, &node->bos, mn_list) {
+ if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
+ return true;
- if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
- continue;
+ if (!mmu_notifier_range_blockable(range))
+ return false;
- r = radeon_bo_reserve(bo, true);
- if (r) {
- DRM_ERROR("(%ld) failed to reserve user bo\n", r);
- continue;
- }
-
- r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv,
- true, false, MAX_SCHEDULE_TIMEOUT);
- if (r <= 0)
- DRM_ERROR("(%ld) failed to wait for user bo\n", r);
-
- radeon_ttm_placement_from_domain(bo, RADEON_GEM_DOMAIN_CPU);
- r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
- if (r)
- DRM_ERROR("(%ld) failed to validate user bo\n", r);
-
- radeon_bo_unreserve(bo);
- }
+ r = radeon_bo_reserve(bo, true);
+ if (r) {
+ DRM_ERROR("(%ld) failed to reserve user bo\n", r);
+ return true;
}
-
-out_unlock:
- mutex_unlock(&rmn->lock);
-
- return ret;
-}
-
-static void radeon_mn_release(struct mmu_notifier *mn, struct mm_struct *mm)
-{
- struct mmu_notifier_range range = {
- .mm = mm,
- .start = 0,
- .end = ULONG_MAX,
- .flags = 0,
- .event = MMU_NOTIFY_UNMAP,
- };
-
- radeon_mn_invalidate_range_start(mn, &range);
-}
-
-static struct mmu_notifier *radeon_mn_alloc_notifier(struct mm_struct *mm)
-{
- struct radeon_mn *rmn;
- rmn = kzalloc(sizeof(*rmn), GFP_KERNEL);
- if (!rmn)
- return ERR_PTR(-ENOMEM);
+ r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
+ MAX_SCHEDULE_TIMEOUT);
+ if (r <= 0)
+ DRM_ERROR("(%ld) failed to wait for user bo\n", r);
- mutex_init(&rmn->lock);
- rmn->objects = RB_ROOT_CACHED;
- return &rmn->mn;
-}
+ radeon_ttm_placement_from_domain(bo, RADEON_GEM_DOMAIN_CPU);
+ r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
+ if (r)
+ DRM_ERROR("(%ld) failed to validate user bo\n", r);
-static void radeon_mn_free_notifier(struct mmu_notifier *mn)
-{
- kfree(container_of(mn, struct radeon_mn, mn));
+ radeon_bo_unreserve(bo);
+ return true;
}
-static const struct mmu_notifier_ops radeon_mn_ops = {
- .release = radeon_mn_release,
- .invalidate_range_start = radeon_mn_invalidate_range_start,
- .alloc_notifier = radeon_mn_alloc_notifier,
- .free_notifier = radeon_mn_free_notifier,
+static const struct mmu_interval_notifier_ops radeon_mn_ops = {
+ .invalidate = radeon_mn_invalidate,
};
/**
@@ -174,51 +94,20 @@ static const struct mmu_notifier_ops radeon_mn_ops = {
*/
int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
{
- unsigned long end = addr + radeon_bo_size(bo) - 1;
- struct mmu_notifier *mn;
- struct radeon_mn *rmn;
- struct radeon_mn_node *node = NULL;
- struct list_head bos;
- struct interval_tree_node *it;
-
- mn = mmu_notifier_get(&radeon_mn_ops, current->mm);
- if (IS_ERR(mn))
- return PTR_ERR(mn);
- rmn = container_of(mn, struct radeon_mn, mn);
-
- INIT_LIST_HEAD(&bos);
-
- mutex_lock(&rmn->lock);
-
- while ((it = interval_tree_iter_first(&rmn->objects, addr, end))) {
- kfree(node);
- node = container_of(it, struct radeon_mn_node, it);
- interval_tree_remove(&node->it, &rmn->objects);
- addr = min(it->start, addr);
- end = max(it->last, end);
- list_splice(&node->bos, &bos);
- }
-
- if (!node) {
- node = kmalloc(sizeof(struct radeon_mn_node), GFP_KERNEL);
- if (!node) {
- mutex_unlock(&rmn->lock);
- return -ENOMEM;
- }
- }
-
- bo->mn = rmn;
-
- node->it.start = addr;
- node->it.last = end;
- INIT_LIST_HEAD(&node->bos);
- list_splice(&bos, &node->bos);
- list_add(&bo->mn_list, &node->bos);
-
- interval_tree_insert(&node->it, &rmn->objects);
-
- mutex_unlock(&rmn->lock);
-
+ int ret;
+
+ ret = mmu_interval_notifier_insert(&bo->notifier, current->mm, addr,
+ radeon_bo_size(bo), &radeon_mn_ops);
+ if (ret)
+ return ret;
+
+ /*
+ * FIXME: radeon appears to allow get_user_pages to run during
+ * invalidate_range_start/end, which is not a safe way to read the
+ * PTEs. It should use the mmu_interval_read_begin() scheme around the
+ * get_user_pages to ensure that the PTEs are read properly
+ */
+ mmu_interval_read_begin(&bo->notifier);
return 0;
}
@@ -231,27 +120,8 @@ int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
*/
void radeon_mn_unregister(struct radeon_bo *bo)
{
- struct radeon_mn *rmn = bo->mn;
- struct list_head *head;
-
- if (!rmn)
+ if (!bo->notifier.mm)
return;
-
- mutex_lock(&rmn->lock);
- /* save the next list entry for later */
- head = bo->mn_list.next;
-
- list_del(&bo->mn_list);
-
- if (list_empty(head)) {
- struct radeon_mn_node *node;
- node = container_of(head, struct radeon_mn_node, bos);
- interval_tree_remove(&node->it, &rmn->objects);
- kfree(node);
- }
-
- mutex_unlock(&rmn->lock);
-
- mmu_notifier_put(&rmn->mn);
- bo->mn = NULL;
+ mmu_interval_notifier_remove(&bo->notifier);
+ bo->notifier.mm = NULL;
}
--
2.24.0
