drm/msm/dpu: merge dpu_hw_intr_get_interrupt_statuses into dpu_hw_intr_dispatch_irqs

There is little sense in reading interrupt statuses and right after that
going after the array of statuses to dispatch them. Merge both loops
into single function doing read and dispatch.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Link: https://lore.kernel.org/r/20210516202910.2141079-2-dmitry.baryshkov@linaro.orgSigned-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c

@@ -376,15 +376,6 @@ void dpu_core_irq_uninstall(struct dpu_kms *dpu_kms)
 
 irqreturn_t dpu_core_irq(struct dpu_kms *dpu_kms)
 {
-	/*
-	 * Read interrupt status from all sources. Interrupt status are
-	 * stored within hw_intr.
-	 * Function will also clear the interrupt status after reading.
-	 * Individual interrupt status bit will only get stored if it
-	 * is enabled.
-	 */
-	dpu_kms->hw_intr->ops.get_interrupt_statuses(dpu_kms->hw_intr);
-
 	/*
 	 * Dispatch to HW driver to handle interrupt lookup that is being
 	 * fired. When matching interrupt is located, HW driver will call to
@@ -392,6 +383,7 @@ irqreturn_t dpu_core_irq(struct dpu_kms *dpu_kms)
 	 * dpu_core_irq_callback_handler will perform the registered function
 	 * callback, and do the interrupt status clearing once the registered
 	 * callback is finished.
+	 * Function will also clear the interrupt status after reading.
 	 */
 	dpu_kms->hw_intr->ops.dispatch_irqs(
 			dpu_kms->hw_intr,

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c

@@ -1371,6 +1371,7 @@ static void dpu_hw_intr_dispatch_irq(struct dpu_hw_intr *intr,
 	int start_idx;
 	int end_idx;
 	u32 irq_status;
+	u32 enable_mask;
 	unsigned long irq_flags;
 
 	if (!intr)
@@ -1383,8 +1384,6 @@ static void dpu_hw_intr_dispatch_irq(struct dpu_hw_intr *intr,
 	 */
 	spin_lock_irqsave(&intr->irq_lock, irq_flags);
 	for (reg_idx = 0; reg_idx < ARRAY_SIZE(dpu_intr_set); reg_idx++) {
-		irq_status = intr->save_irq_status[reg_idx];
-
 		/*
 		 * Each Interrupt register has a range of 64 indexes, and
 		 * that is static for dpu_irq_map.
@@ -1396,6 +1395,20 @@ static void dpu_hw_intr_dispatch_irq(struct dpu_hw_intr *intr,
 			start_idx >= ARRAY_SIZE(dpu_irq_map))
 			continue;
 
+		/* Read interrupt status */
+		irq_status = DPU_REG_READ(&intr->hw, dpu_intr_set[reg_idx].status_off);
+
+		/* Read enable mask */
+		enable_mask = DPU_REG_READ(&intr->hw, dpu_intr_set[reg_idx].en_off);
+
+		/* and clear the interrupt */
+		if (irq_status)
+			DPU_REG_WRITE(&intr->hw, dpu_intr_set[reg_idx].clr_off,
+				     irq_status);
+
+		/* Finally update IRQ status based on enable mask */
+		irq_status &= enable_mask;
+
 		/*
 		 * Search through matching intr status from irq map.
 		 * start_idx and end_idx defined the search range in
@@ -1429,6 +1442,10 @@ static void dpu_hw_intr_dispatch_irq(struct dpu_hw_intr *intr,
 				irq_status &= ~dpu_irq_map[irq_idx].irq_mask;
 			}
 	}
+
+	/* ensure register writes go through */
+	wmb();
+
 	spin_unlock_irqrestore(&intr->irq_lock, irq_flags);
 }
 
@@ -1580,41 +1597,6 @@ static int dpu_hw_intr_disable_irqs(struct dpu_hw_intr *intr)
 	return 0;
 }
 
-static void dpu_hw_intr_get_interrupt_statuses(struct dpu_hw_intr *intr)
-{
-	int i;
-	u32 enable_mask;
-	unsigned long irq_flags;
-
-	if (!intr)
-		return;
-
-	spin_lock_irqsave(&intr->irq_lock, irq_flags);
-	for (i = 0; i < ARRAY_SIZE(dpu_intr_set); i++) {
-		if (!test_bit(i, &intr->irq_mask))
-			continue;
-
-		/* Read interrupt status */
-		intr->save_irq_status[i] = DPU_REG_READ(&intr->hw,
-				dpu_intr_set[i].status_off);
-
-		/* Read enable mask */
-		enable_mask = DPU_REG_READ(&intr->hw, dpu_intr_set[i].en_off);
-
-		/* and clear the interrupt */
-		if (intr->save_irq_status[i])
-			DPU_REG_WRITE(&intr->hw, dpu_intr_set[i].clr_off,
-					intr->save_irq_status[i]);
-
-		/* Finally update IRQ status based on enable mask */
-		intr->save_irq_status[i] &= enable_mask;
-	}
-
-	/* ensure register writes go through */
-	wmb();
-
-	spin_unlock_irqrestore(&intr->irq_lock, irq_flags);
-}
 
 static void dpu_hw_intr_clear_intr_status_nolock(struct dpu_hw_intr *intr,
 		int irq_idx)
@@ -1673,7 +1655,6 @@ static void __setup_intr_ops(struct dpu_hw_intr_ops *ops)
 	ops->dispatch_irqs = dpu_hw_intr_dispatch_irq;
 	ops->clear_all_irqs = dpu_hw_intr_clear_irqs;
 	ops->disable_all_irqs = dpu_hw_intr_disable_irqs;
-	ops->get_interrupt_statuses = dpu_hw_intr_get_interrupt_statuses;
 	ops->clear_intr_status_nolock = dpu_hw_intr_clear_intr_status_nolock;
 	ops->get_interrupt_status = dpu_hw_intr_get_interrupt_status;
 }
@@ -1710,14 +1691,6 @@ struct dpu_hw_intr *dpu_hw_intr_init(void __iomem *addr,
 		return ERR_PTR(-ENOMEM);
 	}
 
-	intr->save_irq_status = kcalloc(ARRAY_SIZE(dpu_intr_set), sizeof(u32),
-			GFP_KERNEL);
-	if (intr->save_irq_status == NULL) {
-		kfree(intr->cache_irq_mask);
-		kfree(intr);
-		return ERR_PTR(-ENOMEM);
-	}
-
 	intr->irq_mask = m->mdss_irqs;
 	intr->obsolete_irq = m->obsolete_irq;
 
@@ -1730,7 +1703,6 @@ void dpu_hw_intr_destroy(struct dpu_hw_intr *intr)
 {
 	if (intr) {
 		kfree(intr->cache_irq_mask);
-		kfree(intr->save_irq_status);
 		kfree(intr);
 	}
 }

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h

@@ -142,14 +142,6 @@ struct dpu_hw_intr_ops {
 			void (*cbfunc)(void *arg, int irq_idx),
 			void *arg);
 
-	/**
-	 * get_interrupt_statuses - Gets and store value from all interrupt
-	 *                          status registers that are currently fired.
-	 * @intr:	HW interrupt handle
-	 */
-	void (*get_interrupt_statuses)(
-			struct dpu_hw_intr *intr);
-
 	/**
 	 * clear_intr_status_nolock() - clears the HW interrupts without lock
 	 * @intr:	HW interrupt handle