ARM: 5901/2: arm/oprofile: reserve the PMU when starting

Make sure that we have access to the performance counters and
that they aren't being used by perf events or anything else.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Jean Pihet <jpihet@mvista.com>
Signed-off-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 19 insertions, 11 deletions

diff --git a/arch/arm/oprofile/op_model_v7.c b/arch/arm/oprofile/op_model_v7.c
index 2088a6c0cc0e..8642d0891ae1 100644
--- a/arch/arm/oprofile/op_model_v7.c
+++ b/arch/arm/oprofile/op_model_v7.c
@@ -11,11 +11,14 @@
  */
 #include <linux/types.h>
 #include <linux/errno.h>
+#include <linux/err.h>
 #include <linux/oprofile.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/smp.h>
 
+#include <asm/pmu.h>
+
 #include "op_counter.h"
 #include "op_arm_model.h"
 #include "op_model_v7.h"
@@ -295,7 +298,7 @@ static irqreturn_t armv7_pmnc_interrupt(int irq, void *arg)
         return IRQ_HANDLED;
 }
 
-int armv7_request_interrupts(int *irqs, int nr)
+int armv7_request_interrupts(const int *irqs, int nr)
 {
         unsigned int i;
         int ret = 0;
@@ -318,7 +321,7 @@ int armv7_request_interrupts(int *irqs, int nr)
         return ret;
 }
 
-void armv7_release_interrupts(int *irqs, int nr)
+void armv7_release_interrupts(const int *irqs, int nr)
 {
         unsigned int i;
 
@@ -362,12 +365,7 @@ static void armv7_pmnc_dump_regs(void)
 }
 #endif
 
-
-static int irqs[] = {
-#ifdef CONFIG_ARCH_OMAP3
-        INT_34XX_BENCH_MPU_EMUL,
-#endif
-};
+static const struct pmu_irqs *pmu_irqs;
 
 static void armv7_pmnc_stop(void)
 {
@@ -375,19 +373,29 @@ static void armv7_pmnc_stop(void)
         armv7_pmnc_dump_regs();
 #endif
         armv7_stop_pmnc();
-        armv7_release_interrupts(irqs, ARRAY_SIZE(irqs));
+        armv7_release_interrupts(pmu_irqs->irqs, pmu_irqs->num_irqs);
+        release_pmu(pmu_irqs);
+        pmu_irqs = NULL;
 }
 
 static int armv7_pmnc_start(void)
 {
         int ret;
 
+        pmu_irqs = reserve_pmu();
+        if (IS_ERR(pmu_irqs))
+                return PTR_ERR(pmu_irqs);
+
 #ifdef DEBUG
         armv7_pmnc_dump_regs();
 #endif
-        ret = armv7_request_interrupts(irqs, ARRAY_SIZE(irqs));
-        if (ret >= 0)
+        ret = armv7_request_interrupts(pmu_irqs->irqs, pmu_irqs->num_irqs);
+        if (ret >= 0) {
                 armv7_start_pmnc();
+        } else {
+                release_pmu(pmu_irqs);
+                pmu_irqs = NULL;
+        }
 
         return ret;
 }