drm/i915: use NULL for zero wakeref_t instead of plain integer 0

As of commit 2edc6a75f2 ("drm/i915: switch intel_wakeref_t underlying
type to struct ref_tracker *") we gained quite a few sparse warnings
about "Using plain integer as NULL pointer" for using 0 to initialize
wakeref_t. Switch to NULL everywhere.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241002181655.582597-1-jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -7694,7 +7694,7 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 	struct intel_crtc_state *new_crtc_state, *old_crtc_state;
 	struct intel_crtc *crtc;
 	struct intel_power_domain_mask put_domains[I915_MAX_PIPES] = {};
-	intel_wakeref_t wakeref = 0;
+	intel_wakeref_t wakeref = NULL;
 	int i;
 
 	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i)

drivers/gpu/drm/i915/display/intel_display_power.c

@@ -545,7 +545,7 @@ intel_display_power_get_if_enabled(struct drm_i915_private *dev_priv,
 
 	wakeref = intel_runtime_pm_get_if_in_use(&dev_priv->runtime_pm);
 	if (!wakeref)
-		return 0;
+		return NULL;
 
 	mutex_lock(&power_domains->lock);
 
@@ -560,7 +560,7 @@ intel_display_power_get_if_enabled(struct drm_i915_private *dev_priv,
 
 	if (!is_enabled) {
 		intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
-		wakeref = 0;
+		wakeref = NULL;
 	}
 
 	return wakeref;
@@ -648,7 +648,7 @@ intel_display_power_put_async_work(struct work_struct *work)
 	struct i915_power_domains *power_domains = &dev_priv->display.power.domains;
 	struct intel_runtime_pm *rpm = &dev_priv->runtime_pm;
 	intel_wakeref_t new_work_wakeref = intel_runtime_pm_get_raw(rpm);
-	intel_wakeref_t old_work_wakeref = 0;
+	intel_wakeref_t old_work_wakeref = NULL;
 
 	mutex_lock(&power_domains->lock);
 

drivers/gpu/drm/i915/display/intel_display_power.h

@@ -297,10 +297,10 @@ void gen9_dbuf_slices_update(struct drm_i915_private *dev_priv,
 
 #define with_intel_display_power(i915, domain, wf) \
 	for ((wf) = intel_display_power_get((i915), (domain)); (wf); \
-	     intel_display_power_put_async((i915), (domain), (wf)), (wf) = 0)
+	     intel_display_power_put_async((i915), (domain), (wf)), (wf) = NULL)
 
 #define with_intel_display_power_if_enabled(i915, domain, wf) \
 	for ((wf) = intel_display_power_get_if_enabled((i915), (domain)); (wf); \
-	     intel_display_power_put_async((i915), (domain), (wf)), (wf) = 0)
+	     intel_display_power_put_async((i915), (domain), (wf)), (wf) = NULL)
 
 #endif /* __INTEL_DISPLAY_POWER_H__ */

drivers/gpu/drm/i915/display/intel_pps.c

@@ -87,7 +87,7 @@ intel_wakeref_t intel_pps_unlock(struct intel_dp *intel_dp,
 	mutex_unlock(&display->pps.mutex);
 	intel_display_power_put(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref);
 
-	return 0;
+	return NULL;
 }
 
 static void

drivers/gpu/drm/i915/gem/i915_gem_shrinker.c

@@ -117,7 +117,7 @@ i915_gem_shrink(struct i915_gem_ww_ctx *ww,
 		},
 		{ NULL, 0 },
 	}, *phase;
-	intel_wakeref_t wakeref = 0;
+	intel_wakeref_t wakeref = NULL;
 	unsigned long count = 0;
 	unsigned long scanned = 0;
 	int err = 0, i = 0;

drivers/gpu/drm/i915/gem/i915_gem_ttm.c

@@ -1038,7 +1038,7 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
 	struct ttm_buffer_object *bo = area->vm_private_data;
 	struct drm_device *dev = bo->base.dev;
 	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
-	intel_wakeref_t wakeref = 0;
+	intel_wakeref_t wakeref = NULL;
 	vm_fault_t ret;
 	int idx;
 
@@ -1195,7 +1195,7 @@ static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj)
 static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj)
 {
 	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
-	intel_wakeref_t wakeref = 0;
+	intel_wakeref_t wakeref = NULL;
 
 	assert_object_held_shared(obj);
 

drivers/gpu/drm/i915/gt/intel_breadcrumbs.c

@@ -70,7 +70,7 @@ static void __intel_breadcrumbs_disarm_irq(struct intel_breadcrumbs *b)
 	if (!--b->irq_enabled)
 		b->irq_disable(b);
 
-	WRITE_ONCE(b->irq_armed, 0);
+	WRITE_ONCE(b->irq_armed, NULL);
 	intel_gt_pm_put_async(b->irq_engine->gt, wakeref);
 }
 

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

@@ -35,7 +35,7 @@ static inline void __intel_gt_pm_get(struct intel_gt *gt)
 static inline intel_wakeref_t intel_gt_pm_get_if_awake(struct intel_gt *gt)
 {
 	if (!intel_wakeref_get_if_active(&gt->wakeref))
-		return 0;
+		return NULL;
 
 	return intel_wakeref_track(&gt->wakeref);
 }
@@ -73,7 +73,7 @@ static inline void intel_gt_pm_put_async(struct intel_gt *gt, intel_wakeref_t ha
 }
 
 #define with_intel_gt_pm(gt, wf) \
-	for (wf = intel_gt_pm_get(gt); wf; intel_gt_pm_put(gt, wf), wf = 0)
+	for ((wf) = intel_gt_pm_get(gt); (wf); intel_gt_pm_put((gt), (wf)), (wf) = NULL)
 
 /**
  * with_intel_gt_pm_if_awake - if GT is PM awake, get a reference to prevent
@@ -84,7 +84,7 @@ static inline void intel_gt_pm_put_async(struct intel_gt *gt, intel_wakeref_t ha
  * @wf: pointer to a temporary wakeref.
  */
 #define with_intel_gt_pm_if_awake(gt, wf) \
-	for (wf = intel_gt_pm_get_if_awake(gt); wf; intel_gt_pm_put_async(gt, wf), wf = 0)
+	for ((wf) = intel_gt_pm_get_if_awake(gt); (wf); intel_gt_pm_put_async((gt), (wf)), (wf) = NULL)
 
 static inline int intel_gt_pm_wait_for_idle(struct intel_gt *gt)
 {

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -1339,7 +1339,7 @@ static ktime_t guc_engine_busyness(struct intel_engine_cs *engine, ktime_t *now)
 	 * start_gt_clk is derived from GuC state. To get a consistent
 	 * view of activity, we query the GuC state only if gt is awake.
 	 */
-	wakeref = in_reset ? 0 : intel_gt_pm_get_if_awake(gt);
+	wakeref = in_reset ? NULL : intel_gt_pm_get_if_awake(gt);
 	if (wakeref) {
 		stats_saved = *stats;
 		gt_stamp_saved = guc->timestamp.gt_stamp;

drivers/gpu/drm/i915/i915_vma.c

@@ -2157,7 +2157,7 @@ static struct dma_fence *__i915_vma_unbind_async(struct i915_vma *vma)
 int i915_vma_unbind(struct i915_vma *vma)
 {
 	struct i915_address_space *vm = vma->vm;
-	intel_wakeref_t wakeref = 0;
+	intel_wakeref_t wakeref = NULL;
 	int err;
 
 	assert_object_held_shared(vma->obj);
@@ -2196,7 +2196,7 @@ int i915_vma_unbind_async(struct i915_vma *vma, bool trylock_vm)
 {
 	struct drm_i915_gem_object *obj = vma->obj;
 	struct i915_address_space *vm = vma->vm;
-	intel_wakeref_t wakeref = 0;
+	intel_wakeref_t wakeref = NULL;
 	struct dma_fence *fence;
 	int err;
 

drivers/gpu/drm/i915/intel_runtime_pm.c

@@ -250,7 +250,7 @@ static intel_wakeref_t __intel_runtime_pm_get_if_active(struct intel_runtime_pm
 		     pm_runtime_get_if_active(rpm->kdev) <= 0) ||
 		    (!ignore_usecount &&
 		     pm_runtime_get_if_in_use(rpm->kdev) <= 0))
-			return 0;
+			return NULL;
 	}
 
 	intel_runtime_pm_acquire(rpm, true);

drivers/gpu/drm/i915/intel_runtime_pm.h

@@ -188,15 +188,15 @@ intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm);
 
 #define with_intel_runtime_pm(rpm, wf) \
 	for ((wf) = intel_runtime_pm_get(rpm); (wf); \
-	     intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
+	     intel_runtime_pm_put((rpm), (wf)), (wf) = NULL)
 
 #define with_intel_runtime_pm_if_in_use(rpm, wf) \
 	for ((wf) = intel_runtime_pm_get_if_in_use(rpm); (wf); \
-	     intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
+	     intel_runtime_pm_put((rpm), (wf)), (wf) = NULL)
 
 #define with_intel_runtime_pm_if_active(rpm, wf) \
 	for ((wf) = intel_runtime_pm_get_if_active(rpm); (wf); \
-	     intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
+	     intel_runtime_pm_put((rpm), (wf)), (wf) = NULL)
 
 void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm);
 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)

drivers/gpu/drm/i915/intel_wakeref.c

@@ -27,11 +27,11 @@ int __intel_wakeref_get_first(struct intel_wakeref *wf)
 	if (!atomic_read(&wf->count)) {
 		INTEL_WAKEREF_BUG_ON(wf->wakeref);
 		wf->wakeref = wakeref;
-		wakeref = 0;
+		wakeref = NULL;
 
 		ret = wf->ops->get(wf);
 		if (ret) {
-			wakeref = xchg(&wf->wakeref, 0);
+			wakeref = xchg(&wf->wakeref, NULL);
 			wake_up_var(&wf->wakeref);
 			goto unlock;
 		}
@@ -52,7 +52,7 @@ int __intel_wakeref_get_first(struct intel_wakeref *wf)
 
 static void ____intel_wakeref_put_last(struct intel_wakeref *wf)
 {
-	intel_wakeref_t wakeref = 0;
+	intel_wakeref_t wakeref = NULL;
 
 	INTEL_WAKEREF_BUG_ON(atomic_read(&wf->count) <= 0);
 	if (unlikely(!atomic_dec_and_test(&wf->count)))
@@ -61,7 +61,7 @@ static void ____intel_wakeref_put_last(struct intel_wakeref *wf)
 	/* ops->put() must reschedule its own release on error/deferral */
 	if (likely(!wf->ops->put(wf))) {
 		INTEL_WAKEREF_BUG_ON(!wf->wakeref);
-		wakeref = xchg(&wf->wakeref, 0);
+		wakeref = xchg(&wf->wakeref, NULL);
 		wake_up_var(&wf->wakeref);
 	}
 
@@ -107,7 +107,7 @@ void __intel_wakeref_init(struct intel_wakeref *wf,
 
 	__mutex_init(&wf->mutex, "wakeref.mutex", &key->mutex);
 	atomic_set(&wf->count, 0);
-	wf->wakeref = 0;
+	wf->wakeref = NULL;
 
 	INIT_DELAYED_WORK(&wf->work, __intel_wakeref_put_work);
 	lockdep_init_map(&wf->work.work.lockdep_map,
@@ -142,7 +142,7 @@ static void wakeref_auto_timeout(struct timer_list *t)
 	if (!refcount_dec_and_lock_irqsave(&wf->count, &wf->lock, &flags))
 		return;
 
-	wakeref = fetch_and_zero(&wf->wakeref);
+	wakeref = xchg(&wf->wakeref, NULL);
 	spin_unlock_irqrestore(&wf->lock, flags);
 
 	intel_runtime_pm_put(&wf->i915->runtime_pm, wakeref);
@@ -154,7 +154,7 @@ void intel_wakeref_auto_init(struct intel_wakeref_auto *wf,
 	spin_lock_init(&wf->lock);
 	timer_setup(&wf->timer, wakeref_auto_timeout, 0);
 	refcount_set(&wf->count, 0);
-	wf->wakeref = 0;
+	wf->wakeref = NULL;
 	wf->i915 = i915;
 }
 

drivers/gpu/drm/i915/pxp/intel_pxp.c

@@ -531,7 +531,7 @@ void intel_pxp_invalidate(struct intel_pxp *pxp)
 		if (ctx->pxp_wakeref) {
 			intel_runtime_pm_put(&i915->runtime_pm,
 					     ctx->pxp_wakeref);
-			ctx->pxp_wakeref = 0;
+			ctx->pxp_wakeref = NULL;
 		}
 
 		spin_lock_irq(&i915->gem.contexts.lock);

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

@@ -24,14 +24,14 @@ static inline intel_wakeref_t intel_runtime_pm_get(struct xe_runtime_pm *pm)
 {
 	struct xe_device *xe = container_of(pm, struct xe_device, runtime_pm);
 
-	return xe_pm_runtime_resume_and_get(xe) ? INTEL_WAKEREF_DEF : 0;
+	return xe_pm_runtime_resume_and_get(xe) ? INTEL_WAKEREF_DEF : NULL;
 }
 
 static inline intel_wakeref_t intel_runtime_pm_get_if_in_use(struct xe_runtime_pm *pm)
 {
 	struct xe_device *xe = container_of(pm, struct xe_device, runtime_pm);
 
-	return xe_pm_runtime_get_if_in_use(xe) ? INTEL_WAKEREF_DEF : 0;
+	return xe_pm_runtime_get_if_in_use(xe) ? INTEL_WAKEREF_DEF : NULL;
 }
 
 static inline intel_wakeref_t intel_runtime_pm_get_noresume(struct xe_runtime_pm *pm)
@@ -63,6 +63,6 @@ static inline void intel_runtime_pm_put(struct xe_runtime_pm *pm, intel_wakeref_
 
 #define with_intel_runtime_pm(rpm, wf) \
 	for ((wf) = intel_runtime_pm_get(rpm); (wf); \
-	     intel_runtime_pm_put((rpm), (wf)), (wf) = 0)
+	     intel_runtime_pm_put((rpm), (wf)), (wf) = NULL)
 
 #endif