Commit 2edc6a75 authored by Jani Nikula's avatar Jani Nikula
Browse files

drm/i915: switch intel_wakeref_t underlying type to struct ref_tracker * 



For intel_wakeref_t, opaque is reasonable, but disguising the underlying
struct ref_tracker * as an unsigned long is not so great. Update the
typedef to remove one level of disguise.

Although the kernel coding style strongly discourages pointer typedefs,
it's a better alternative, and an incremental improvement on the status
quo. It provides much better type safety than an unsigned long could,
and prevents passing magic -1 instead of INTEL_WAKEREF_DEF. Moreover, it
provides a gradual path for replacing intel_wakeref_t with struct
ref_tracker * if desired.

As an extra safety measure, check for error pointers in
intel_ref_tracker_free() before passing them on to ref_tracker_free(),
to catch any mistakes with mock gt special wakeref value.

Reviewed-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/cca2b0631f816ad90461aa1bf4fe3f80c0e13464.1726680898.git.jani.nikula@intel.com


Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
parent bc549f8f

drivers/gpu/drm/i915/gt/intel_gt_pm.h

+1 −1
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ int intel_gt_runtime_resume(struct intel_gt *gt); 


ktime_t intel_gt_get_awake_time(const struct intel_gt *gt);



#define INTEL_WAKEREF_MOCK_GT ((intel_wakeref_t)-ENODEV)

#define INTEL_WAKEREF_MOCK_GT ERR_PTR(-ENODEV)



static inline bool is_mock_gt(const struct intel_gt *gt)

{

drivers/gpu/drm/i915/intel_wakeref.h

+9 −7
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ 
#include <linux/timer.h>

#include <linux/workqueue.h>



typedef unsigned long intel_wakeref_t;

typedef struct ref_tracker *intel_wakeref_t;



#define INTEL_REFTRACK_DEAD_COUNT 16

#define INTEL_REFTRACK_PRINT_LIMIT 16
@@ -273,7 +273,7 @@ __intel_wakeref_defer_park(struct intel_wakeref *wf) 
 */

int intel_wakeref_wait_for_idle(struct intel_wakeref *wf);



#define INTEL_WAKEREF_DEF ((intel_wakeref_t)(-1))

#define INTEL_WAKEREF_DEF ERR_PTR(-ENOENT)



static inline intel_wakeref_t intel_ref_tracker_alloc(struct ref_tracker_dir *dir)

{
@@ -281,17 +281,19 @@ static inline intel_wakeref_t intel_ref_tracker_alloc(struct ref_tracker_dir *di 


	ref_tracker_alloc(dir, &user, GFP_NOWAIT);



	return (intel_wakeref_t)user ?: INTEL_WAKEREF_DEF;

	return user ?: INTEL_WAKEREF_DEF;

}



static inline void intel_ref_tracker_free(struct ref_tracker_dir *dir,

					  intel_wakeref_t handle)

					  intel_wakeref_t wakeref)

{

	struct ref_tracker *user;

	if (wakeref == INTEL_WAKEREF_DEF)

		wakeref = NULL;



	user = (handle == INTEL_WAKEREF_DEF) ? NULL : (void *)handle;

	if (WARN_ON(IS_ERR(wakeref)))

		return;



	ref_tracker_free(dir, &user);

	ref_tracker_free(dir, &wakeref);

}



void intel_ref_tracker_show(struct ref_tracker_dir *dir,

drivers/gpu/drm/xe/compat-i915-headers/intel_wakeref.h

+2 −2
Original line number Diff line number Diff line
@@ -5,6 +5,6 @@ 


#include <linux/types.h>



typedef unsigned long intel_wakeref_t;

typedef struct ref_tracker *intel_wakeref_t;



#define INTEL_WAKEREF_DEF ((intel_wakeref_t)(-1))
 
#define INTEL_WAKEREF_DEF ERR_PTR(-ENOENT)