[linux-yocto] [PATCH 04/94] arch/powerpc: Fix PMU interrupts
Paul Butler
butler.paul at gmail.com
Thu Nov 7 17:12:18 PST 2013
From: David Mercado <david.mercado at windriver.com>
The PMU interrupts were previously initialized at too early in the
board init process, so IRQ affinity wasn't working. Moved PMU IRQ
setup/teardown to PMU enable/disable routines instead. With this
change, PMU interrupts correctly work across all cores.
Signed-off-by: David Mercado <david.mercado at windriver.com>
---
arch/powerpc/perf/core-lsi-acp.c | 115 ++++++++++++++++++++++++++++++++++++++-
arch/powerpc/perf/ppc476-pmu.c | 59 --------------------
2 files changed, 113 insertions(+), 61 deletions(-)
diff --git a/arch/powerpc/perf/core-lsi-acp.c b/arch/powerpc/perf/core-lsi-acp.c
index 9e8986d..28437b5 100644
--- a/arch/powerpc/perf/core-lsi-acp.c
+++ b/arch/powerpc/perf/core-lsi-acp.c
@@ -12,6 +12,8 @@
*/
#include <linux/kernel.h>
+#include <linux/cpumask.h>
+#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/perf_event.h>
#include <linux/percpu.h>
@@ -53,6 +55,115 @@ static inline int perf_intr_is_nmi(struct pt_regs *regs)
static void perf_event_interrupt(struct pt_regs *regs);
+static int cpu_to_pmu_irq(int cpu)
+{
+ int hwirq;
+
+ /*
+ * NOTE: On the LSI ACP platform, the PMU interrupts are
+ * hard-wired as inputs to the MPIC. The irq numbers are
+ * fixed as follows:
+ *
+ * Core 0 PMU: IRQ 95
+ * Core 1 PMU: IRQ 94
+ * Core 2 PMU: IRQ 93
+ * Core 3 PMU: IRQ 92
+ *
+ * The IRQ assignment should probably be done in the DTB,
+ * like ARM does, but no other PowerPC platform does this.
+ * So for now, we hard-code the numbers here.
+ */
+ if (cpu == 0)
+ hwirq = 95;
+ else if (cpu == 1)
+ hwirq = 94;
+ else if (cpu == 2)
+ hwirq = 93;
+ else if (cpu == 3)
+ hwirq = 92;
+ else
+ hwirq = 0;
+
+ return hwirq;
+}
+
+static cpumask_t active_irqs;
+
+/* PMU IRQ handler */
+static irqreturn_t acp_pmu_isr(int irq, void *dev_id)
+{
+ __get_cpu_var(irq_stat).pmu_irqs++;
+ perf_irq(get_irq_regs());
+ return IRQ_HANDLED;
+}
+
+static void acp_pmu_release_hardware(void)
+{
+ int i, irq, virq;
+
+ for (i = 0; i < num_possible_cpus(); ++i) {
+ if (!cpumask_test_and_clear_cpu(i, &active_irqs))
+ continue;
+ irq = cpu_to_pmu_irq(i);
+ if (irq) {
+ free_irq(irq, NULL);
+ virq = irq_find_mapping(NULL, irq);
+ if (virq)
+ irq_dispose_mapping(virq);
+ }
+ }
+
+ release_pmc_hardware();
+}
+
+static int acp_pmu_reserve_hardware(void)
+{
+ int err = 0;
+ int i, irq, hwirq;
+
+ err = reserve_pmc_hardware(perf_event_interrupt);
+
+ if (err) {
+ pr_warning("unable to reserve pmu\n");
+ return err;
+ }
+
+ for (i = 0; i < num_possible_cpus(); ++i) {
+ err = 0;
+
+ hwirq = cpu_to_pmu_irq(i);
+ if (!hwirq)
+ continue;
+
+ irq = irq_create_mapping(NULL, hwirq);
+ if (irq == NO_IRQ) {
+ pr_err("PMU irq_create_mapping() failed\n");
+ continue;
+ }
+
+ irq = cpu_to_pmu_irq(i);
+ if (irq < 0)
+ continue;
+
+ if (irq_set_affinity(irq, cpumask_of(i))) {
+ pr_warning("PMU IRQ affinity failed (irq=%d, cpu=%d)\n",
+ irq, i);
+ continue;
+ }
+ err = request_irq(irq, acp_pmu_isr,
+ IRQF_DISABLED | IRQF_NOBALANCING,
+ "pmu", NULL);
+ if (err) {
+ pr_err("PMU reqeust for IRQ%d failed\n", irq);
+ acp_pmu_release_hardware();
+ return err;
+ }
+ cpumask_set_cpu(i, &active_irqs);
+ }
+
+ return 0;
+}
+
static void acp_pmu_read(struct perf_event *event)
{
@@ -339,7 +450,7 @@ static void hw_perf_event_destroy(struct perf_event *event)
if (!atomic_add_unless(&num_events, -1, 1)) {
mutex_lock(&pmc_reserve_mutex);
if (atomic_dec_return(&num_events) == 0)
- release_pmc_hardware();
+ acp_pmu_release_hardware();
mutex_unlock(&pmc_reserve_mutex);
}
}
@@ -445,7 +556,7 @@ static int acp_pmu_event_init(struct perf_event *event)
mutex_lock(&pmc_reserve_mutex);
if (atomic_read(&num_events) == 0 &&
- reserve_pmc_hardware(perf_event_interrupt))
+ acp_pmu_reserve_hardware())
err = -EBUSY;
else
atomic_inc(&num_events);
diff --git a/arch/powerpc/perf/ppc476-pmu.c b/arch/powerpc/perf/ppc476-pmu.c
index 9bd9060..30c05d9 100644
--- a/arch/powerpc/perf/ppc476-pmu.c
+++ b/arch/powerpc/perf/ppc476-pmu.c
@@ -19,14 +19,6 @@
#include <asm/perf_event_acp.h>
#include <asm/reg_acp_pmu.h>
-/* PMU IRQ handler */
-static irqreturn_t acp_pmu_isr(int irq, void *dev_id)
-{
- __get_cpu_var(irq_stat).pmu_irqs++;
- perf_irq(get_irq_regs());
- return IRQ_HANDLED;
-}
-
/*
* Map of generic hardware event types to hardware events
* Zero if unsupported
@@ -129,13 +121,6 @@ static struct acp_pmu ppc476_pmu = {
static int init_ppc476_pmu(void)
{
- unsigned int irq;
- int intNum, core;
- static const char * const irqname[] = { "pmu-core0",
- "pmu-core1",
- "pmu-core2",
- "pmu-core3" };
-
if (!cur_cpu_spec->oprofile_cpu_type)
return -ENODEV;
@@ -144,50 +129,6 @@ static int init_ppc476_pmu(void)
else
return -ENODEV;
- /*
- * Install the PMU interrupt handlers:
- *
- * NOTE: On the LSI ACP platform, the PMU interrupts are
- * hard-wired as inputs to the MPIC. The irq numbers are
- * fixed as follows:
- *
- * Core 0 PMU: IRQ 95
- * Core 1 PMU: IRQ 94
- * Core 2 PMU: IRQ 93
- * Core 3 PMU: IRQ 92
- *
- * The IRQ assignment should probably be done in the DTB,
- * like ARM does, but no other PowerPC platform does this.
- * So for now, we hard-code the numbers here.
- */
- for_each_possible_cpu(core) {
- if (core == 0)
- intNum = 95;
- else if (core == 1)
- intNum = 94;
- else if (core == 2)
- intNum = 93;
- else if (core == 3)
- intNum = 92;
- else
- break;
-
- irq = irq_create_mapping(NULL, intNum);
- if (irq == NO_IRQ) {
- pr_err("PMU irq_create_mapping() failed\n");
- break;
- }
- if (irq_set_affinity(irq, get_cpu_mask(core))) {
- pr_warning("PMU IRQ affinity failed (irq=%d, cpu=%d)\n",
- irq, core);
- continue;
- }
- if (request_irq(irq, acp_pmu_isr,
- IRQF_DISABLED | IRQF_NOBALANCING,
- irqname[core], NULL))
- pr_err("PMU reqeust for IRQ%d failed\n", irq);
- }
-
return register_acp_pmu(&ppc476_pmu);
}
--
1.8.3.4
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