[PATCH 3.4 185/214] drm/ttm: Fix memory type compatibility check

Greg Kroah-Hartman
2014-06-05T04:31:47Z

From: Thomas Hellstrom <thellstrom@vmware.com>

commit 59c8e66378fb78adbcd05f0d09783dde6fef282b upstream.

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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/ttm/ttm_bo.c | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)

--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1091,24 +1091,32 @@ 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;
}
- return -1;
+
+ 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 false;
}

int ttm_bo_validate(struct ttm_buffer_object *bo,
@@ -1117,6 +1125,7 @@ int ttm_bo_validate(struct ttm_buffer_ob
bool no_wait_gpu)
{
int ret;
+ uint32_t new_flags;

BUG_ON(!atomic_read(&bo->reserved));
/* Check that range is valid */
@@ -1127,8 +1136,7 @@ int ttm_bo_validate(struct ttm_buffer_ob
/*
* 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_reserve, no_wait_gpu);
if (ret)
return ret;
@@ -1137,7 +1145,7 @@ int ttm_bo_validate(struct ttm_buffer_ob
* 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);
}
/*