[PATCH v1 4/9]powerpc/powernv: Add generic nest pmu ops

From: Madhavan Srinivasan
Date: Tue Jun 02 2015 - 12:02:48 EST


Patch adds generic nest pmu functions and format attribute.

Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Cc: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/perf/nest-pmu.c | 107 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 107 insertions(+)

diff --git a/arch/powerpc/perf/nest-pmu.c b/arch/powerpc/perf/nest-pmu.c
index 3e7010e..345707c 100644
--- a/arch/powerpc/perf/nest-pmu.c
+++ b/arch/powerpc/perf/nest-pmu.c
@@ -134,6 +134,113 @@ void cpumask_chip(void)
cpu_notifier_register_done();
}

+PMU_FORMAT_ATTR(event, "config:0-20");
+struct attribute *p8_nest_format_attrs[] = {
+ &format_attr_event.attr,
+ NULL,
+};
+
+struct attribute_group p8_nest_format_group = {
+ .name = "format",
+ .attrs = p8_nest_format_attrs,
+};
+
+int p8_nest_event_init(struct perf_event *event)
+{
+ int chip_id;
+
+ if (event->attr.type != event->pmu->type)
+ return -ENOENT;
+
+ /* Sampling not supported yet */
+ if (event->hw.sample_period)
+ return -EINVAL;
+
+ /* unsupported modes and filters */
+ if (event->attr.exclude_user ||
+ event->attr.exclude_kernel ||
+ event->attr.exclude_hv ||
+ event->attr.exclude_idle ||
+ event->attr.exclude_host ||
+ event->attr.exclude_guest ||
+ event->attr.sample_period) /* no sampling */
+ return -EINVAL;
+
+ if (event->cpu < 0)
+ return -EINVAL;
+
+ chip_id = topology_physical_package_id(event->cpu);
+ event->hw.event_base = event->attr.config +
+ p8_perchip_nest_info[chip_id].vbase;
+
+ return 0;
+}
+
+void p8_nest_read_counter(struct perf_event *event)
+{
+ u64 *addr;
+ u64 data = 0;
+
+ addr = (u64 *)event->hw.event_base;
+ data = __be64_to_cpu((uint64_t)*addr);
+ local64_set(&event->hw.prev_count, data);
+}
+
+void p8_nest_perf_event_update(struct perf_event *event)
+{
+ u64 counter_prev, counter_new, final_count;
+ uint64_t *addr;
+
+ addr = (u64 *)event->hw.event_base;
+ counter_prev = local64_read(&event->hw.prev_count);
+ counter_new = __be64_to_cpu((uint64_t)*addr);
+ final_count = counter_new - counter_prev;
+
+ local64_set(&event->hw.prev_count, counter_new);
+ local64_add(final_count, &event->count);
+}
+
+void p8_nest_event_start(struct perf_event *event, int flags)
+{
+ event->hw.state = 0;
+ p8_nest_read_counter(event);
+}
+
+void p8_nest_event_stop(struct perf_event *event, int flags)
+{
+ p8_nest_perf_event_update(event);
+}
+
+int p8_nest_event_add(struct perf_event *event, int flags)
+{
+ p8_nest_event_start(event, flags);
+ return 0;
+}
+
+void p8_nest_event_del(struct perf_event *event, int flags)
+{
+ p8_nest_event_stop(event, flags);
+}
+
+/*
+ * Populate pmu ops in the structure
+ */
+static int update_pmu_ops(struct nest_pmu *pmu)
+{
+ if (!pmu)
+ return -EINVAL;
+
+ pmu->pmu.task_ctx_nr = perf_invalid_context;
+ pmu->pmu.event_init = p8_nest_event_init;
+ pmu->pmu.add = p8_nest_event_add;
+ pmu->pmu.del = p8_nest_event_del;
+ pmu->pmu.start = p8_nest_event_start;
+ pmu->pmu.stop = p8_nest_event_stop;
+ pmu->pmu.read = p8_nest_perf_event_update;
+ pmu->pmu.attr_groups = pmu->attr_groups;
+
+ return 0;
+}

static int __init nest_pmu_init(void)
{
--
1.9.1

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