[Intel-gfx] [PATCH 7/7] drm/i915: Trim unused workaround list entries

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

The new workaround list allocator grows the list in chunks so will end up
with some unused space. Trim it when the initialization phase is done to
free up a tiny bit of slab.

v2:
 * Simplify with kmemdup. (Chris Wilson)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/intel_workarounds.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_workarounds.c b/drivers/gpu/drm/i915/intel_workarounds.c
index 3e6b388ea022..9d876d554e57 100644
--- a/drivers/gpu/drm/i915/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/intel_workarounds.c
@@ -55,6 +55,19 @@ static void wa_init_start(struct i915_wa_list *wal, const char *name)
 
 static void wa_init_finish(struct i915_wa_list *wal)
 {
+	/* Trim unused entries. */
+	if (wal->count < wal->__size) {
+		struct i915_wa *list = kmemdup(wal->list,
+					       wal->count * sizeof(*list),
+					       GFP_KERNEL);
+
+		if (list) {
+			kfree(wal->list);
+			wal->list = list;
+			wal->__size = wal->count;
+		}
+	}
+
 	if (wal->count)
 		DRM_DEBUG_DRIVER("Initialized %u %s workarounds\n",
 				 wal->wa_count, wal->name);
-- 
2.19.1