[PATCH v8 6/7] powerpc/perf: generic nest pmu event functions

[Madhavan Srinivasan]

Add set of generic nest pmu related event functions to be used by
each nest pmu. Add code to setup format attribute and 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: Daniel Axtens <dja@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx>
---
 arch/powerpc/perf/nest-pmu.c | 114 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)

diff --git a/arch/powerpc/perf/nest-pmu.c b/arch/powerpc/perf/nest-pmu.c
index b9b44147c9b8..772e4d2d7a04 100644
--- a/arch/powerpc/perf/nest-pmu.c
+++ b/arch/powerpc/perf/nest-pmu.c
@@ -13,6 +13,111 @@
 struct perchip_nest_info nest_perchip_info[NEST_MAX_CHIPS];
 struct nest_pmu *per_nest_pmu_arr[NEST_MAX_PMUS];
 
+PMU_FORMAT_ATTR(event, "config:0-20");
+static struct attribute *nest_format_attrs[] = {
+	&format_attr_event.attr,
+	NULL,
+};
+
+static struct attribute_group nest_format_group = {
+	.name = "format",
+	.attrs = nest_format_attrs,
+};
+
+static int nest_event_init(struct perf_event *event)
+{
+	int chip_id;
+	u32 config = event->attr.config;
+	struct perchip_nest_info *pcni;
+
+	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);
+	pcni = &nest_perchip_info[chip_id];
+	event->hw.event_base = pcni->vbase[config/PAGE_SIZE] +
+							(config & ~PAGE_MASK );
+
+	return 0;
+}
+
+static void nest_read_counter(struct perf_event *event)
+{
+	u64 *addr, data;
+
+	addr = (u64 *)event->hw.event_base;
+	data = __be64_to_cpu(*addr);
+	local64_set(&event->hw.prev_count, data);
+}
+
+static void nest_perf_event_update(struct perf_event *event)
+{
+	u64 counter_prev, counter_new, final_count, *addr;
+
+	addr = (u64 *)event->hw.event_base;
+	counter_prev = local64_read(&event->hw.prev_count);
+	counter_new = __be64_to_cpu(*addr);
+	final_count = counter_new - counter_prev;
+
+	local64_set(&event->hw.prev_count, counter_new);
+	local64_add(final_count, &event->count);
+}
+
+static void nest_event_start(struct perf_event *event, int flags)
+{
+	nest_read_counter(event);
+}
+
+static void nest_event_stop(struct perf_event *event, int flags)
+{
+	if (flags & PERF_EF_UPDATE)
+		nest_perf_event_update(event);
+}
+
+static int nest_event_add(struct perf_event *event, int flags)
+{
+       if (flags & PERF_EF_START)
+               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 = nest_event_init;
+	pmu->pmu.add = nest_event_add;
+	pmu->pmu.del = nest_event_stop;
+	pmu->pmu.start = nest_event_start;
+	pmu->pmu.stop = nest_event_stop;
+	pmu->pmu.read = nest_perf_event_update;
+	pmu->attr_groups[1] = &nest_format_group;
+	pmu->pmu.attr_groups = pmu->attr_groups;
+
+	return 0;
+}
 /*
  * Populate event name and string in attribute
  */
@@ -62,8 +167,17 @@ static int update_events_in_group(
 int init_nest_pmu(struct nest_ima_events *nest_events,
 					int idx, struct nest_pmu *pmu_ptr)
 {
+	int ret = -ENODEV;
 
 	update_events_in_group(nest_events, idx, pmu_ptr);
+	update_pmu_ops(pmu_ptr);
+
+	ret = perf_pmu_register(&pmu_ptr->pmu, pmu_ptr->pmu.name, -1);
+	if (ret)
+		return ret;
+
+	pr_info("%s performance monitor hardware support registered\n",
+							pmu_ptr->pmu.name);
 	return 0;
 }
 
-- 
1.9.1