[patch v1 2/3] arm: pmu: support pmu irq routed from CTI

[tom.leiming at gmail.com]

From: Ming Lei <tom.leiming at gmail.com>

This patch introduces pmu_platform_data struct to
support pmu irq routed from CTI, such as implemented
on OMAP4.

Generally speaking, clearing cti irq should be done in
irq handler, also enabling cti module after calling
request_irq and disabling cti module before calling
free_irq.

Signed-off-by: Ming Lei <tom.leiming at gmail.com>
---
 arch/arm/include/asm/pmu.h   |   12 +++++++++
 arch/arm/kernel/perf_event.c |   57 ++++++++++++++++++++++++++++++-----------
 2 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h
index 7544ce6..6162aaf 100644
--- a/arch/arm/include/asm/pmu.h
+++ b/arch/arm/include/asm/pmu.h
@@ -13,20 +13,32 @@
 #define __ARM_PMU_H__
 
 #include <linux/interrupt.h>
+#include <asm/cti.h>
 
 enum arm_pmu_type {
 	ARM_PMU_DEVICE_CPU	= 0,
 	ARM_NUM_PMU_DEVICES,
 };
 
+#define MAX_CTI_NUM  4
 /*
  * struct arm_pmu_platdata - ARM PMU platform data
  *
+ * @use_cti_irq: pmu irq is routed from cti
+ * @cti_cnt: cti counts used for pmu irq routing
+ * @cti: cti instances used to help access cti registers
  * @handle_irq: an optional handler which will be called from the interrupt and
  * passed the address of the low level handler, and can be used to implement
  * any platform specific handling before or after calling it.
+ *
+ * If pmu irq is routed from CTI, @use_cti_irq, @cti_cnt and
+ * @cti must be initialized and passed to pmu driver.
  */
 struct arm_pmu_platdata {
+	int use_cti_irq;
+	int cti_cnt;
+	struct cti cti[MAX_CTI_NUM];
+
 	irqreturn_t (*handle_irq)(int irq, void *dev,
 				  irq_handler_t pmu_handler);
 };
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 22e194eb..9027a8f 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -377,18 +377,39 @@ validate_group(struct perf_event *event)
 	return 0;
 }
 
-static irqreturn_t armpmu_platform_irq(int irq, void *dev)
+static inline int cti_irq(struct arm_pmu_platdata *data)
 {
-	struct arm_pmu_platdata *plat = dev_get_platdata(&pmu_device->dev);
+	return data && data->use_cti_irq;
+}
+
+static inline struct cti *irq_to_cti(struct arm_pmu_platdata *data,
+	int irq)
+{
+	int idx;
 
-	return plat->handle_irq(irq, dev, armpmu->handle_irq);
+	for(idx = 0; idx < data->cti_cnt; idx++)
+		if (data->cti[idx].irq == irq)
+			return &data->cti[idx];
+	return NULL;
+}
+
+static inline irqreturn_t armpmu_handle_irq(int irq_num, void *dev)
+{
+	struct arm_pmu_platdata *plat = dev;
+
+	if (cti_irq(plat))
+		cti_irq_ack(irq_to_cti(plat, irq_num));
+
+	if (plat && plat->handle_irq)
+		return plat->handle_irq(irq_num, dev, armpmu->handle_irq);
+	else
+		return armpmu->handle_irq(irq_num, NULL);
 }
 
 static int
 armpmu_reserve_hardware(void)
 {
 	struct arm_pmu_platdata *plat;
-	irq_handler_t handle_irq;
 	int i, err = -ENODEV, irq;
 
 	pmu_device = reserve_pmu(ARM_PMU_DEVICE_CPU);
@@ -399,11 +420,7 @@ armpmu_reserve_hardware(void)
 
 	init_pmu(ARM_PMU_DEVICE_CPU);
 
-	plat = dev_get_platdata(&pmu_device->dev);
-	if (plat && plat->handle_irq)
-		handle_irq = armpmu_platform_irq;
-	else
-		handle_irq = armpmu->handle_irq;
+	plat = platform_get_drvdata(pmu_device);
 
 	if (pmu_device->num_resources < 1) {
 		pr_err("no irqs for PMUs defined\n");
@@ -415,21 +432,25 @@ armpmu_reserve_hardware(void)
 		if (irq < 0)
 			continue;
 
-		err = request_irq(irq, handle_irq,
+		err = request_irq(irq, armpmu_handle_irq,
 				  IRQF_DISABLED | IRQF_NOBALANCING,
-				  "armpmu", NULL);
+				  "armpmu", plat);
 		if (err) {
 			pr_warning("unable to request IRQ%d for ARM perf "
 				"counters\n", irq);
 			break;
-		}
+		} else if (cti_irq(plat))
+			cti_enable(irq_to_cti(plat, irq));
 	}
 
 	if (err) {
 		for (i = i - 1; i >= 0; --i) {
 			irq = platform_get_irq(pmu_device, i);
-			if (irq >= 0)
-				free_irq(irq, NULL);
+			if (irq >= 0) {
+				if (cti_irq(plat))
+					cti_disable(irq_to_cti(plat, irq));
+				free_irq(irq, plat);
+			}
 		}
 		release_pmu(pmu_device);
 		pmu_device = NULL;
@@ -442,11 +463,15 @@ static void
 armpmu_release_hardware(void)
 {
 	int i, irq;
+	struct arm_pmu_platdata *plat = platform_get_drvdata(pmu_device);
 
 	for (i = pmu_device->num_resources - 1; i >= 0; --i) {
 		irq = platform_get_irq(pmu_device, i);
-		if (irq >= 0)
-			free_irq(irq, NULL);
+		if (irq >= 0) {
+			if (cti_irq(plat))
+				cti_disable(irq_to_cti(plat, irq));
+			free_irq(irq, plat);
+		}
 	}
 	armpmu->stop();
 
-- 
1.7.3