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: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/cca2b0631f816ad90461aa1bf4fe3f80c0e13464.1726680898.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Jani Nikula 2024-09-18 20:35:48 +03:00
parent bc549f8fc6
commit 2edc6a75f2
3 changed files with 12 additions and 10 deletions

View file

@ -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)
{

View file

@ -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,

View file

@ -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)