drm/i915: clear the gpu reloc batch

The reloc batch is short lived but can exist in the user visible ppGTT,
and since it's backed by an internal object, which lacks page clearing,
we should take care to clear it upfront.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201224151358.401345-2-matthew.auld@intel.com
Cc: stable@vger.kernel.org
(cherry picked from commit 26ebc511e799f621357982ccc37a7987a56a00f4)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index bcc80f4..bd3046e 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -1046,7 +1046,7 @@ static void reloc_gpu_flush(struct i915_execbuffer *eb, struct reloc_cache *cach
        GEM_BUG_ON(cache->rq_size >= obj->base.size / sizeof(u32));
        cache->rq_cmd[cache->rq_size] = MI_BATCH_BUFFER_END;
 
-       __i915_gem_object_flush_map(obj, 0, sizeof(u32) * (cache->rq_size + 1));
+       i915_gem_object_flush_map(obj);
        i915_gem_object_unpin_map(obj);
 
        intel_gt_chipset_flush(cache->rq->engine->gt);
@@ -1296,6 +1296,8 @@ static int __reloc_gpu_alloc(struct i915_execbuffer *eb,
                goto err_pool;
        }
 
+       memset32(cmd, 0, pool->obj->base.size / sizeof(u32));
+
        batch = i915_vma_instance(pool->obj, vma->vm, NULL);
        if (IS_ERR(batch)) {
                err = PTR_ERR(batch);