[PATCH 2/8] drm/i915/pmu: Let resource survive unbind

[Lucas De Marchi]

There's no need to free the resources during unbind. Since perf events
may still access them due to open events, it's safer to free them when
dropping the last i915 reference. It will also allow to ask perf to
release its own resources when dropping the last reference in a follow
up change.

Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/i915/i915_pmu.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index 67b6cbdeff1da..4d05d98f51b8e 100644
--- a/drivers/gpu/drm/i915/i915_pmu.c
+++ b/drivers/gpu/drm/i915/i915_pmu.c
@@ -5,6 +5,7 @@
  */
 
 #include <linux/pm_runtime.h>
+#include <drm/drm_managed.h>
 
 #include "gt/intel_engine.h"
 #include "gt/intel_engine_pm.h"
@@ -1148,6 +1149,17 @@ static void free_event_attributes(struct i915_pmu *pmu)
 	pmu->pmu_attr = NULL;
 }
 
+static void free_pmu(struct drm_device *dev, void *res)
+{
+	struct i915_pmu *pmu = res;
+	struct drm_i915_private *i915 = pmu_to_i915(pmu);
+
+	free_event_attributes(pmu);
+	kfree(pmu->base.attr_groups);
+	if (IS_DGFX(i915))
+		kfree(pmu->name);
+}
+
 static int i915_pmu_cpu_online(unsigned int cpu, struct hlist_node *node)
 {
 	struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), cpuhp.node);
@@ -1296,6 +1308,9 @@ void i915_pmu_register(struct drm_i915_private *i915)
 	if (ret)
 		goto err_unreg;
 
+	if (drmm_add_action(&i915->drm, free_pmu, pmu))
+		goto err_unreg;
+
 	return;
 
 err_unreg:
@@ -1330,11 +1345,7 @@ void i915_pmu_unregister(struct drm_i915_private *i915)
 	hrtimer_cancel(&pmu->timer);
 
 	i915_pmu_unregister_cpuhp_state(pmu);
-
 	perf_pmu_unregister(&pmu->base);
+
 	pmu->base.event_init = NULL;
-	kfree(pmu->base.attr_groups);
-	if (IS_DGFX(i915))
-		kfree(pmu->name);
-	free_event_attributes(pmu);
 }
-- 
2.47.0