drm/exec: Pass in initial # of objects

In cases where the # is known ahead of time, it is silly to do the table
resize dance.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Patchwork: https://patchwork.freedesktop.org/patch/568338/

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_exec.c b/drivers/gpu/drm/drm_exec.c
index 5d2809de4517..48ee851b61d9 100644
--- a/drivers/gpu/drm/drm_exec.c
+++ b/drivers/gpu/drm/drm_exec.c
@@ -69,16 +69,23 @@ static void drm_exec_unlock_all(struct drm_exec *exec)
  * drm_exec_init - initialize a drm_exec object
  * @exec: the drm_exec object to initialize
  * @flags: controls locking behavior, see DRM_EXEC_* defines
+ * @nr: the initial # of objects
  *
  * Initialize the object and make sure that we can track locked objects.
+ *
+ * If nr is non-zero then it is used as the initial objects table size.
+ * In either case, the table will grow (be re-allocated) on demand.
  */
-void drm_exec_init(struct drm_exec *exec, uint32_t flags)
+void drm_exec_init(struct drm_exec *exec, uint32_t flags, unsigned nr)
 {
+	if (!nr)
+		nr = PAGE_SIZE / sizeof(void *);
+
 	exec->flags = flags;
-	exec->objects = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	exec->objects = kvmalloc_array(nr, sizeof(void *), GFP_KERNEL);
 
 	/* If allocation here fails, just delay that till the first use */
-	exec->max_objects = exec->objects ? PAGE_SIZE / sizeof(void *) : 0;
+	exec->max_objects = exec->objects ? nr : 0;
 	exec->num_objects = 0;
 	exec->contended = DRM_EXEC_DUMMY;
 	exec->prelocked = NULL;