drm/ttm: Fix memory type compatibility check

Also check the busy placements before deciding to move a buffer object.
Failing to do this may result in a completely unneccessary move within a
single memory type.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
Cc: stable@vger.kernel.org

1 files changed, 20 insertions, 12 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 6c1a38f53066..8d5a646ebe6a 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -998,24 +998,32 @@ out_unlock:
         return ret;
 }
 
-static int ttm_bo_mem_compat(struct ttm_placement *placement,
-                             struct ttm_mem_reg *mem)
+static bool ttm_bo_mem_compat(struct ttm_placement *placement,
+                              struct ttm_mem_reg *mem,
+                              uint32_t *new_flags)
 {
         int i;
 
         if (mem->mm_node && placement->lpfn != 0 &&
             (mem->start < placement->fpfn ||
              mem->start + mem->num_pages > placement->lpfn))
-                return -1;
+                return false;
 
         for (i = 0; i < placement->num_placement; i++) {
-                if ((placement->placement[i] & mem->placement &
-                        TTM_PL_MASK_CACHING) &&
-                        (placement->placement[i] & mem->placement &
-                        TTM_PL_MASK_MEM))
-                        return i;
+                *new_flags = placement->placement[i];
+                if ((*new_flags & mem->placement & TTM_PL_MASK_CACHING) &&
+                    (*new_flags & mem->placement & TTM_PL_MASK_MEM))
+                        return true;
+        }
+
+        for (i = 0; i < placement->num_busy_placement; i++) {
+                *new_flags = placement->busy_placement[i];
+                if ((*new_flags & mem->placement & TTM_PL_MASK_CACHING) &&
+                    (*new_flags & mem->placement & TTM_PL_MASK_MEM))
+                        return true;
         }
-        return -1;
+
+        return false;
 }
 
 int ttm_bo_validate(struct ttm_buffer_object *bo,
@@ -1024,6 +1032,7 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
                         bool no_wait_gpu)
 {
         int ret;
+        uint32_t new_flags;
 
         lockdep_assert_held(&bo->resv->lock.base);
         /* Check that range is valid */
@@ -1034,8 +1043,7 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
         /*
          * Check whether we need to move buffer.
          */
-        ret = ttm_bo_mem_compat(placement, &bo->mem);
-        if (ret < 0) {
+        if (!ttm_bo_mem_compat(placement, &bo->mem, &new_flags)) {
                 ret = ttm_bo_move_buffer(bo, placement, interruptible,
                                          no_wait_gpu);
                 if (ret)
@@ -1045,7 +1053,7 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
                  * Use the access and other non-mapping-related flag bits from
                  * the compatible memory placement flags to the active flags
                  */
-                ttm_flag_masked(&bo->mem.placement, placement->placement[ret],
+                ttm_flag_masked(&bo->mem.placement, new_flags,
                                 ~TTM_PL_MASK_MEMTYPE);
         }
         /*