[PATCH v8 5/7] powerpc/perf: Add event attribute and group to nest pmu

[Madhavan Srinivasan <maddy@linux.vnet.ibm.com>]

Device tree nest driver module parses the nest unit and its events.
It pass the information to nest pmu code which is placed in
perf/ as "nest-pmu.c".

Inthis patch code added to create only event attributes and
attribute groups for the nest pmu.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 arch/powerpc/perf/Makefile                 |  2 +-
 arch/powerpc/perf/nest-pmu.c               | 69 ++++++++++++++++++++++++++++++
 arch/powerpc/platforms/powernv/opal-nest.c |  8 ++++
 3 files changed, 78 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/perf/nest-pmu.c

diff --git a/arch/powerpc/perf/Makefile b/arch/powerpc/perf/Makefile
index f9c083a5652a..6da656b50e3c 100644
--- a/arch/powerpc/perf/Makefile
+++ b/arch/powerpc/perf/Makefile
@@ -5,7 +5,7 @@ obj-$(CONFIG_PERF_EVENTS)	+= callchain.o
 obj-$(CONFIG_PPC_PERF_CTRS)	+= core-book3s.o bhrb.o
 obj64-$(CONFIG_PPC_PERF_CTRS)	+= power4-pmu.o ppc970-pmu.o power5-pmu.o \
 				   power5+-pmu.o power6-pmu.o power7-pmu.o \
-				   power8-pmu.o
+				   power8-pmu.o nest-pmu.o
 obj32-$(CONFIG_PPC_PERF_CTRS)	+= mpc7450-pmu.o
 
 obj-$(CONFIG_FSL_EMB_PERF_EVENT) += core-fsl-emb.o
diff --git a/arch/powerpc/perf/nest-pmu.c b/arch/powerpc/perf/nest-pmu.c
new file mode 100644
index 000000000000..b9b44147c9b8
--- /dev/null
+++ b/arch/powerpc/perf/nest-pmu.c
@@ -0,0 +1,69 @@
+/*
+ * Nest Performance Monitor counter support.
+ *
+ * Copyright (C) 2016 Madhavan Srinivasan, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <asm/nest-pmu.h>
+
+struct perchip_nest_info nest_perchip_info[NEST_MAX_CHIPS];
+struct nest_pmu *per_nest_pmu_arr[NEST_MAX_PMUS];
+
+/*
+ * Populate event name and string in attribute
+ */
+static struct attribute *dev_str_attr(const char *name, const char *str)
+{
+	struct perf_pmu_events_attr *attr;
+
+	attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+
+	sysfs_attr_init(&attr->attr.attr);
+
+	attr->event_str = str;
+	attr->attr.attr.name = name;
+	attr->attr.attr.mode = 0444;
+	attr->attr.show = perf_event_sysfs_show;
+
+	return &attr->attr.attr;
+}
+
+static int update_events_in_group(
+	struct nest_ima_events *nest_events, int idx, struct nest_pmu *pmu)
+{
+	struct attribute_group *attr_group;
+	struct attribute **attrs;
+	int i;
+
+	/* Allocate memory for attribute group */
+	attr_group = kzalloc(sizeof(*attr_group), GFP_KERNEL);
+	if (!attr_group)
+		return -ENOMEM;
+
+	/* Allocate memory for attributes */
+	attrs = kzalloc((sizeof(struct attribute *) * (idx + 1)), GFP_KERNEL);
+	if (!attrs)
+		return -ENOMEM;
+
+	attr_group->name = "events";
+	attr_group->attrs = attrs;
+	for (i = 0; i < idx; i++, nest_events++)
+		attrs[i] = dev_str_attr((char *)nest_events->ev_name,
+						(char *)nest_events->ev_value);
+
+	pmu->attr_groups[0] = attr_group;
+	return 0;
+}
+
+int init_nest_pmu(struct nest_ima_events *nest_events,
+					int idx, struct nest_pmu *pmu_ptr)
+{
+
+	update_events_in_group(nest_events, idx, pmu_ptr);
+	return 0;
+}
+
diff --git a/arch/powerpc/platforms/powernv/opal-nest.c b/arch/powerpc/platforms/powernv/opal-nest.c
index 548a8c0236e4..6ad260353d04 100644
--- a/arch/powerpc/platforms/powernv/opal-nest.c
+++ b/arch/powerpc/platforms/powernv/opal-nest.c
@@ -32,6 +32,8 @@
 
 extern struct perchip_nest_info nest_perchip_info[NEST_MAX_CHIPS];
 extern struct nest_pmu *per_nest_pmu_arr[NEST_MAX_PMUS];
+extern int init_nest_pmu(struct nest_ima_events *nest_events,
+				int idx, struct nest_pmu *pmu_ptr);
 
 static int nest_event_info(char *name, struct nest_ima_events *nest_events)
 {
@@ -210,6 +212,12 @@ static int nest_pmu_create(struct device_node *parent, int pmu_index)
 		idx += ret;
 	}
 
+	ret = init_nest_pmu(nest_events, idx, pmu_ptr);
+	if (ret) {
+		pr_err("Nest PMU %s Register failed\n", pmu_ptr->pmu.name);
+		return ret;
+	}
+
 	return 0;
 }
 
-- 
1.9.1