drm/amdgpu: fix issue with overlapping userptrs

Otherwise we could try to evict overlapping userptr BOs in get_user_pages(),
leading to a possible circular locking dependency.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 55cf05e1c81c..6442a06d6fdc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -783,6 +783,25 @@ bool amdgpu_ttm_tt_has_userptr(struct ttm_tt *ttm)
         return !!gtt->userptr;
 }
 
+bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
+                                  unsigned long end)
+{
+        struct amdgpu_ttm_tt *gtt = (void *)ttm;
+        unsigned long size;
+
+        if (gtt == NULL)
+                return false;
+
+        if (gtt->ttm.ttm.state != tt_bound || !gtt->userptr)
+                return false;
+
+        size = (unsigned long)gtt->ttm.ttm.num_pages * PAGE_SIZE;
+        if (gtt->userptr > end || gtt->userptr + size <= start)
+                return false;
+
+        return true;
+}
+
 bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm)
 {
         struct amdgpu_ttm_tt *gtt = (void *)ttm;