[PATCH v2 6/7]powerpc/powernv: generic nest pmu event functions

From: Madhavan Srinivasan
Date: Thu Jun 11 2015 - 01:20:10 EST


Add generic format attribute and set of generic nest pmu related
event functions to be used by each nest pmu. Add code to register nest pmus.

Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Anton Blanchard <anton@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 | 109 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 109 insertions(+)

diff --git a/arch/powerpc/perf/nest-pmu.c b/arch/powerpc/perf/nest-pmu.c
index 8fad2d9..a662c14 100644
--- a/arch/powerpc/perf/nest-pmu.c
+++ b/arch/powerpc/perf/nest-pmu.c
@@ -13,6 +13,108 @@
static struct perchip_nest_info p8_perchip_nest_info[P8_MAX_CHIP];
static struct nest_pmu *per_nest_pmu_arr[P8_MAX_NEST_PMUS];

+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,
+};
+
+static 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)
+ 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;
+}
+
+static 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);
+}
+
+static 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);
+}
+
+static void p8_nest_event_start(struct perf_event *event, int flags)
+{
+ event->hw.state = 0;
+ p8_nest_read_counter(event);
+}
+
+static void p8_nest_event_stop(struct perf_event *event, int flags)
+{
+ p8_nest_perf_event_update(event);
+}
+
+static int p8_nest_event_add(struct perf_event *event, int flags)
+{
+ p8_nest_event_start(event, flags);
+ return 0;
+}
+
+/*
+ * 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_stop;
+ 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;
+}
+
/*
* Populate event name and string in attribute
*/
@@ -106,6 +208,7 @@ static int nest_pmu_create(struct device_node *dev, int pmu_index)
/* Save the name to register the PMU with it */
sprintf(buf, "Nest_%s", (char *)pp->value);
pmu_ptr->pmu.name = (char *)buf;
+ pmu_ptr->attr_groups[1] = &p8_nest_format_group;
}

/* Skip these, we dont need it */
@@ -179,6 +282,12 @@ static int nest_pmu_create(struct device_node *dev, int pmu_index)
(struct ppc64_nest_ima_events *)p8_events_arr,
idx, pmu_ptr);

+ update_pmu_ops(pmu_ptr);
+
+ /* Register the pmu */
+ perf_pmu_register(&pmu_ptr->pmu, pmu_ptr->pmu.name, -1);
+ printk(KERN_INFO "Nest PMU %s Registered\n", pmu_ptr->pmu.name);
+
return 0;
}

--
1.9.1

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