[RFC 1/2] drm/xe: Introduce PM guard classes

[Michal Wajdeczko]

There is support for 'classes' with constructor and destructor
semantics that can be used for scope-based resource management,
like our device power management.

Use provided macros from linux/cleanup.h to generate required
code definitions.

This should allow us to use:

	scoped_guard(xe_pm, xe)
		foo();
or
	CLASS(xe_pm, var)(xe);

without any concern of leaking the pm reference.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/xe/xe_pm.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_pm.h b/drivers/gpu/drm/xe/xe_pm.h
index 104a21ae6dfd..26293a3b18af 100644
--- a/drivers/gpu/drm/xe/xe_pm.h
+++ b/drivers/gpu/drm/xe/xe_pm.h
@@ -6,6 +6,7 @@
 #ifndef _XE_PM_H_
 #define _XE_PM_H_
 
+#include <linux/cleanup.h>
 #include <linux/pm_runtime.h>
 
 #define DEFAULT_VRAM_THRESHOLD 300 /* in MB */
@@ -33,4 +34,8 @@ int xe_pm_set_vram_threshold(struct xe_device *xe, u32 threshold);
 void xe_pm_d3cold_allowed_toggle(struct xe_device *xe);
 struct task_struct *xe_pm_read_callback_task(struct xe_device *xe);
 
+DEFINE_GUARD(xe_pm, struct xe_device *, xe_pm_runtime_get(_T), xe_pm_runtime_put(_T))
+DEFINE_GUARD_COND(xe_pm, _if_active, xe_pm_runtime_get_if_active(_T))
+DEFINE_GUARD_COND(xe_pm, _if_in_use, xe_pm_runtime_get_if_in_use(_T))
+
 #endif
-- 
2.43.0