diff mbox series

[2/2] perf:arm-ni: support PMUs to share IRQs for different clock domains

Message ID 20250410114214.1599777-3-allen.wang@hj-micro.com (mailing list archive)
State New
Headers show
Series perf:arm-ni: support PMUs to share IRQs | expand

Commit Message

Shouping Wang April 10, 2025, 11:42 a.m. UTC 
The ARM NI700 contains multiple clock domains, each with a PMU.
In some hardware implementations, these PMUs under the same device
share a common interrupt line. The current codes implementation
only supports requesting a separate IRQ for each clock domain's PMU.

Here, a single interrupt handler is registered for shared interrupt.
Within this handler, the interrupt status of all PMUs sharing the
interrupt is checked.

Signed-off-by: Shouping Wang <allen.wang@hj-micro.com>
---
 drivers/perf/arm-ni.c | 77 +++++++++++++++++++++++++++++--------------
 1 file changed, 53 insertions(+), 24 deletions(-)

Comments

Robin Murphy April 17, 2025, 2:41 p.m. UTC | #1 
On 10/04/2025 12:42 pm, Shouping Wang wrote:
> The ARM NI700 contains multiple clock domains, each with a PMU.
> In some hardware implementations, these PMUs under the same device
> share a common interrupt line. The current codes implementation
> only supports requesting a separate IRQ for each clock domain's PMU.
> 
> Here, a single interrupt handler is registered for shared interrupt.
> Within this handler, the interrupt status of all PMUs sharing the
> interrupt is checked.

Unfortunately this isn't sufficient for sharing an IRQ between multiple 
PMUs - the CPU affinity and hotplug context migration must be kept in 
sync as well.

I guess I really should get back to my old plan to factor out a common 
helper library for all this stuff - that was the main reason I left 
combined IRQ support out of the initial version here rather than do 
another copy-paste of the arm_dmc620 design again...

Thanks,
Robin.

> Signed-off-by: Shouping Wang <allen.wang@hj-micro.com>
> ---
>   drivers/perf/arm-ni.c | 77 +++++++++++++++++++++++++++++--------------
>   1 file changed, 53 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/perf/arm-ni.c b/drivers/perf/arm-ni.c
> index 3f3d2e0f91fa..611085e89436 100644
> --- a/drivers/perf/arm-ni.c
> +++ b/drivers/perf/arm-ni.c
> @@ -104,6 +104,7 @@ struct arm_ni_cd {
>   	u16 id;
>   	int num_units;
>   	int irq;
> +	s8 irq_friend;
>   	int cpu;
>   	struct hlist_node cpuhp_node;
>   	struct pmu pmu;
> @@ -446,26 +447,31 @@ static irqreturn_t arm_ni_handle_irq(int irq, void *dev_id)
>   {
>   	struct arm_ni_cd *cd = dev_id;
>   	irqreturn_t ret = IRQ_NONE;
> -	u32 reg = readl_relaxed(cd->pmu_base + NI_PMOVSCLR);
> +	u32 reg;
>   
> -	if (reg & (1U << NI_CCNT_IDX)) {
> -		ret = IRQ_HANDLED;
> -		if (!(WARN_ON(!cd->ccnt))) {
> -			arm_ni_event_read(cd->ccnt);
> -			arm_ni_init_ccnt(cd);
> +	for (;;) {
> +		reg = readl_relaxed(cd->pmu_base + NI_PMOVSCLR);
> +		if (reg & (1U << NI_CCNT_IDX)) {
> +			ret = IRQ_HANDLED;
> +			if (!(WARN_ON(!cd->ccnt))) {
> +				arm_ni_event_read(cd->ccnt);
> +				arm_ni_init_ccnt(cd);
> +			}
>   		}
> -	}
> -	for (int i = 0; i < NI_NUM_COUNTERS; i++) {
> -		if (!(reg & (1U << i)))
> -			continue;
> -		ret = IRQ_HANDLED;
> -		if (!(WARN_ON(!cd->evcnt[i]))) {
> -			arm_ni_event_read(cd->evcnt[i]);
> -			arm_ni_init_evcnt(cd, i);
> +		for (int i = 0; i < NI_NUM_COUNTERS; i++) {
> +			if (!(reg & (1U << i)))
> +				continue;
> +			ret = IRQ_HANDLED;
> +			if (!(WARN_ON(!cd->evcnt[i]))) {
> +				arm_ni_event_read(cd->evcnt[i]);
> +				arm_ni_init_evcnt(cd, i);
> +			}
>   		}
> +		writel_relaxed(reg, cd->pmu_base + NI_PMOVSCLR);
> +		if (!cd->irq_friend)
> +			return ret;
> +		cd += cd->irq_friend;
>   	}
> -	writel_relaxed(reg, cd->pmu_base + NI_PMOVSCLR);
> -	return ret;
>   }
>   
>   static int arm_ni_init_cd(struct arm_ni *ni, struct arm_ni_node *node, u64 res_start)
> @@ -538,12 +544,6 @@ static int arm_ni_init_cd(struct arm_ni *ni, struct arm_ni_node *node, u64 res_s
>   	if (cd->irq < 0)
>   		return cd->irq;
>   
> -	err = devm_request_irq(ni->dev, cd->irq, arm_ni_handle_irq,
> -			       IRQF_NOBALANCING | IRQF_NO_THREAD,
> -			       dev_name(ni->dev), cd);
> -	if (err)
> -		return err;
> -
>   	cd->cpu = cpumask_local_spread(0, dev_to_node(ni->dev));
>   	cd->pmu = (struct pmu) {
>   		.module = THIS_MODULE,
> @@ -603,6 +603,30 @@ static void arm_ni_probe_domain(void __iomem *base, struct arm_ni_node *node)
>   	node->num_components = readl_relaxed(base + NI_CHILD_NODE_INFO);
>   }
>   
> +static int arm_ni_irq_init(struct arm_ni *ni)
> +{
> +	int irq;
> +	int err = 0;
> +
> +	for (int i = 0; i < ni->num_cds; i++) {
> +		irq = ni->cds[i].irq;
> +		for (int j = i; j--; ) {
> +			if (ni->cds[j].irq == irq) {
> +				ni->cds[j].irq_friend = i-j;
> +				goto next;
> +			}
> +		}
> +		err =  devm_request_irq(ni->dev, irq, arm_ni_handle_irq,
> +					IRQF_NOBALANCING | IRQF_NO_THREAD,
> +					 dev_name(ni->dev), &ni->cds[i]);
> +		if (err)
> +			return err;
> +next:
> +		;
> +	}
> +	return 0;
> +}
> +
>   static int arm_ni_probe(struct platform_device *pdev)
>   {
>   	struct arm_ni_node cfg, vd, pd, cd;
> @@ -611,6 +635,7 @@ static int arm_ni_probe(struct platform_device *pdev)
>   	void __iomem *base;
>   	static atomic_t id;
>   	int num_cds;
> +	int ret;
>   	u32 reg, part;
>   
>   	/*
> @@ -669,8 +694,6 @@ static int arm_ni_probe(struct platform_device *pdev)
>   			reg = readl_relaxed(vd.base + NI_CHILD_PTR(p));
>   			arm_ni_probe_domain(base + reg, &pd);
>   			for (int c = 0; c < pd.num_components; c++) {
> -				int ret;
> -
>   				reg = readl_relaxed(pd.base + NI_CHILD_PTR(c));
>   				arm_ni_probe_domain(base + reg, &cd);
>   				ret = arm_ni_init_cd(ni, &cd, res->start);
> @@ -683,6 +706,12 @@ static int arm_ni_probe(struct platform_device *pdev)
>   		}
>   	}
>   
> +	ret = arm_ni_irq_init(ni);
> +	if (ret) {
> +		arm_ni_remove(pdev);
> +		return ret;
> +	}
> +
>   	return 0;
>   }
>
diff mbox series

Patch

diff --git a/drivers/perf/arm-ni.c b/drivers/perf/arm-ni.c
index 3f3d2e0f91fa..611085e89436 100644
--- a/drivers/perf/arm-ni.c
+++ b/drivers/perf/arm-ni.c
@@ -104,6 +104,7 @@  struct arm_ni_cd {
 	u16 id;
 	int num_units;
 	int irq;
+	s8 irq_friend;
 	int cpu;
 	struct hlist_node cpuhp_node;
 	struct pmu pmu;
@@ -446,26 +447,31 @@  static irqreturn_t arm_ni_handle_irq(int irq, void *dev_id)
 {
 	struct arm_ni_cd *cd = dev_id;
 	irqreturn_t ret = IRQ_NONE;
-	u32 reg = readl_relaxed(cd->pmu_base + NI_PMOVSCLR);
+	u32 reg;
 
-	if (reg & (1U << NI_CCNT_IDX)) {
-		ret = IRQ_HANDLED;
-		if (!(WARN_ON(!cd->ccnt))) {
-			arm_ni_event_read(cd->ccnt);
-			arm_ni_init_ccnt(cd);
+	for (;;) {
+		reg = readl_relaxed(cd->pmu_base + NI_PMOVSCLR);
+		if (reg & (1U << NI_CCNT_IDX)) {
+			ret = IRQ_HANDLED;
+			if (!(WARN_ON(!cd->ccnt))) {
+				arm_ni_event_read(cd->ccnt);
+				arm_ni_init_ccnt(cd);
+			}
 		}
-	}
-	for (int i = 0; i < NI_NUM_COUNTERS; i++) {
-		if (!(reg & (1U << i)))
-			continue;
-		ret = IRQ_HANDLED;
-		if (!(WARN_ON(!cd->evcnt[i]))) {
-			arm_ni_event_read(cd->evcnt[i]);
-			arm_ni_init_evcnt(cd, i);
+		for (int i = 0; i < NI_NUM_COUNTERS; i++) {
+			if (!(reg & (1U << i)))
+				continue;
+			ret = IRQ_HANDLED;
+			if (!(WARN_ON(!cd->evcnt[i]))) {
+				arm_ni_event_read(cd->evcnt[i]);
+				arm_ni_init_evcnt(cd, i);
+			}
 		}
+		writel_relaxed(reg, cd->pmu_base + NI_PMOVSCLR);
+		if (!cd->irq_friend)
+			return ret;
+		cd += cd->irq_friend;
 	}
-	writel_relaxed(reg, cd->pmu_base + NI_PMOVSCLR);
-	return ret;
 }
 
 static int arm_ni_init_cd(struct arm_ni *ni, struct arm_ni_node *node, u64 res_start)
@@ -538,12 +544,6 @@  static int arm_ni_init_cd(struct arm_ni *ni, struct arm_ni_node *node, u64 res_s
 	if (cd->irq < 0)
 		return cd->irq;
 
-	err = devm_request_irq(ni->dev, cd->irq, arm_ni_handle_irq,
-			       IRQF_NOBALANCING | IRQF_NO_THREAD,
-			       dev_name(ni->dev), cd);
-	if (err)
-		return err;
-
 	cd->cpu = cpumask_local_spread(0, dev_to_node(ni->dev));
 	cd->pmu = (struct pmu) {
 		.module = THIS_MODULE,
@@ -603,6 +603,30 @@  static void arm_ni_probe_domain(void __iomem *base, struct arm_ni_node *node)
 	node->num_components = readl_relaxed(base + NI_CHILD_NODE_INFO);
 }
 
+static int arm_ni_irq_init(struct arm_ni *ni)
+{
+	int irq;
+	int err = 0;
+
+	for (int i = 0; i < ni->num_cds; i++) {
+		irq = ni->cds[i].irq;
+		for (int j = i; j--; ) {
+			if (ni->cds[j].irq == irq) {
+				ni->cds[j].irq_friend = i-j;
+				goto next;
+			}
+		}
+		err =  devm_request_irq(ni->dev, irq, arm_ni_handle_irq,
+					IRQF_NOBALANCING | IRQF_NO_THREAD,
+					 dev_name(ni->dev), &ni->cds[i]);
+		if (err)
+			return err;
+next:
+		;
+	}
+	return 0;
+}
+
 static int arm_ni_probe(struct platform_device *pdev)
 {
 	struct arm_ni_node cfg, vd, pd, cd;
@@ -611,6 +635,7 @@  static int arm_ni_probe(struct platform_device *pdev)
 	void __iomem *base;
 	static atomic_t id;
 	int num_cds;
+	int ret;
 	u32 reg, part;
 
 	/*
@@ -669,8 +694,6 @@  static int arm_ni_probe(struct platform_device *pdev)
 			reg = readl_relaxed(vd.base + NI_CHILD_PTR(p));
 			arm_ni_probe_domain(base + reg, &pd);
 			for (int c = 0; c < pd.num_components; c++) {
-				int ret;
-
 				reg = readl_relaxed(pd.base + NI_CHILD_PTR(c));
 				arm_ni_probe_domain(base + reg, &cd);
 				ret = arm_ni_init_cd(ni, &cd, res->start);
@@ -683,6 +706,12 @@  static int arm_ni_probe(struct platform_device *pdev)
 		}
 	}
 
+	ret = arm_ni_irq_init(ni);
+	if (ret) {
+		arm_ni_remove(pdev);
+		return ret;
+	}
+
 	return 0;
 }