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>

3 files changed, 23 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 82edf95b7740..d0fee29ebeba 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -2360,6 +2360,8 @@ bool amdgpu_ttm_bo_is_amdgpu_bo(struct ttm_buffer_object *bo);
 int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
                                      uint32_t flags);
 bool amdgpu_ttm_tt_has_userptr(struct ttm_tt *ttm);
+bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
+                                  unsigned long end);
 bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm);
 uint32_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
                                  struct ttm_mem_reg *mem);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index b1969f2b2038..d4e2780c0796 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -142,7 +142,8 @@ static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
 
                 list_for_each_entry(bo, &node->bos, mn_list) {
 
-                        if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
+                        if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start,
+                                                          end))
                                 continue;
 
                         r = amdgpu_bo_reserve(bo, true);
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;