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_v6.c b/arch/arm/oprofile/op_model_v6.c
index f7d2ec5ee9a1..a22357a2fd08 100644
--- a/arch/arm/oprofile/op_model_v6.c
+++ b/arch/arm/oprofile/op_model_v6.c
@@ -19,39 +19,47 @@
 /* #define DEBUG */
 #include <linux/types.h>
 #include <linux/errno.h>
+#include <linux/err.h>
 #include <linux/sched.h>
 #include <linux/oprofile.h>
 #include <linux/interrupt.h>
 #include <asm/irq.h>
 #include <asm/system.h>
+#include <asm/pmu.h>
 
 #include "op_counter.h"
 #include "op_arm_model.h"
 #include "op_model_arm11_core.h"
 
-static int irqs[] = {
-#ifdef CONFIG_ARCH_OMAP2
-        3,
-#endif
-#ifdef CONFIG_ARCH_BCMRING
-        IRQ_PMUIRQ, /* for BCMRING, ARM PMU interrupt is 43 */
-#endif
-};
+static const struct pmu_irqs *pmu_irqs;
 
 static void armv6_pmu_stop(void)
 {
         arm11_stop_pmu();
-        arm11_release_interrupts(irqs, ARRAY_SIZE(irqs));
+        arm11_release_interrupts(pmu_irqs->irqs, pmu_irqs->num_irqs);
+        release_pmu(pmu_irqs);
+        pmu_irqs = NULL;
 }
 
 static int armv6_pmu_start(void)
 {
         int ret;
 
-        ret = arm11_request_interrupts(irqs, ARRAY_SIZE(irqs));
-        if (ret >= 0)
+        pmu_irqs = reserve_pmu();
+        if (IS_ERR(pmu_irqs)) {
+                ret = PTR_ERR(pmu_irqs);
+                goto out;
+        }
+
+        ret = arm11_request_interrupts(pmu_irqs->irqs, pmu_irqs->num_irqs);
+        if (ret >= 0) {
                 ret = arm11_start_pmu();
+        } else {
+                release_pmu(pmu_irqs);
+                pmu_irqs = NULL;
+        }
 
+out:
         return ret;
 }