powerpc/powernv: Add support to clear sensor groups data

Adds support for clearing different sensor groups. OCC inband sensor
groups like CSM, Profiler, Job Scheduler can be cleared using this
driver. The min/max of all sensors belonging to these sensor groups
will be cleared.
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Documentation/devicetree/bindings/powerpc/opal/sensor-groups.txt

+IBM OPAL Sensor Groups Binding
+-------------------------------
+
+Node: /ibm,opal/sensor-groups
+
+Description: Contains sensor groups available in the Powernv P9
+servers. Each child node indicates a sensor group.
+
+- compatible : Should be "ibm,opal-sensor-group"
+
+Each child node contains below properties:
+
+- type : String to indicate the type of sensor-group
+
+- sensor-group-id: Abstract unique identifier provided by firmware of
+		   type <u32> which is used for sensor-group
+		   operations like clearing the min/max history of all
+		   sensors belonging to the group.
+
+- ibm,chip-id : Chip ID
+
+- sensors : Phandle array of child nodes of /ibm,opal/sensor/
+	    belonging to this group
+
+- ops : Array of opal-call numbers indicating available operations on
+	sensor groups like clearing min/max, enabling/disabling sensor
+	group.

arch/powerpc/include/asm/opal-api.h

@@ -198,6 +198,7 @@
 #define OPAL_SET_POWERCAP			153
 #define OPAL_GET_POWER_SHIFT_RATIO		154
 #define OPAL_SET_POWER_SHIFT_RATIO		155
+#define OPAL_SENSOR_GROUP_CLEAR			156
 #define OPAL_PCI_SET_P2P			157
 #define OPAL_LAST				157
 

arch/powerpc/include/asm/opal.h

@@ -279,6 +279,7 @@ int opal_get_powercap(u32 handle, int token, u32 *pcap);
 int opal_set_powercap(u32 handle, int token, u32 pcap);
 int opal_get_power_shift_ratio(u32 handle, int token, u32 *psr);
 int opal_set_power_shift_ratio(u32 handle, int token, u32 psr);
+int opal_sensor_group_clear(u32 group_hndl, int token);
 
 /* Internal functions */
 extern int early_init_dt_scan_opal(unsigned long node, const char *uname,
@@ -359,6 +360,7 @@ void opal_wake_poller(void);
 
 void opal_powercap_init(void);
 void opal_psr_init(void);
+void opal_sensor_groups_init(void);
 
 #endif /* __ASSEMBLY__ */
 

arch/powerpc/platforms/powernv/Makefile

@@ -2,7 +2,7 @@ obj-y			+= setup.o opal-wrappers.o opal.o opal-async.o idle.o
 obj-y			+= opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
 obj-y			+= rng.o opal-elog.o opal-dump.o opal-sysparam.o opal-sensor.o
 obj-y			+= opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
-obj-y			+= opal-kmsg.o opal-powercap.o opal-psr.o
+obj-y			+= opal-kmsg.o opal-powercap.o opal-psr.o opal-sensor-groups.o
 
 obj-$(CONFIG_SMP)	+= smp.o subcore.o subcore-asm.o
 obj-$(CONFIG_PCI)	+= pci.o pci-ioda.o npu-dma.o

arch/powerpc/platforms/powernv/opal-sensor-groups.c

+/*
+ * PowerNV OPAL Sensor-groups interface
+ *
+ * Copyright 2017 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt)     "opal-sensor-groups: " fmt
+
+#include <linux/of.h>
+#include <linux/kobject.h>
+#include <linux/slab.h>
+
+#include <asm/opal.h>
+
+DEFINE_MUTEX(sg_mutex);
+
+static struct kobject *sg_kobj;
+
+struct sg_attr {
+	u32 handle;
+	struct kobj_attribute attr;
+};
+
+static struct sensor_group {
+	char name[20];
+	struct attribute_group sg;
+	struct sg_attr *sgattrs;
+} *sgs;
+
+static ssize_t sg_store(struct kobject *kobj, struct kobj_attribute *attr,
+			const char *buf, size_t count)
+{
+	struct sg_attr *sattr = container_of(attr, struct sg_attr, attr);
+	struct opal_msg msg;
+	u32 data;
+	int ret, token;
+
+	ret = kstrtoint(buf, 0, &data);
+	if (ret)
+		return ret;
+
+	if (data != 1)
+		return -EINVAL;
+
+	token = opal_async_get_token_interruptible();
+	if (token < 0) {
+		pr_devel("Failed to get token\n");
+		return token;
+	}
+
+	ret = mutex_lock_interruptible(&sg_mutex);
+	if (ret)
+		goto out_token;
+
+	ret = opal_sensor_group_clear(sattr->handle, token);
+	switch (ret) {
+	case OPAL_ASYNC_COMPLETION:
+		ret = opal_async_wait_response(token, &msg);
+		if (ret) {
+			pr_devel("Failed to wait for the async response\n");
+			ret = -EIO;
+			goto out;
+		}
+		ret = opal_error_code(opal_get_async_rc(msg));
+		if (!ret)
+			ret = count;
+		break;
+	case OPAL_SUCCESS:
+		ret = count;
+		break;
+	default:
+		ret = opal_error_code(ret);
+	}
+
+out:
+	mutex_unlock(&sg_mutex);
+out_token:
+	opal_async_release_token(token);
+	return ret;
+}
+
+static struct sg_ops_info {
+	int opal_no;
+	const char *attr_name;
+	ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
+			const char *buf, size_t count);
+} ops_info[] = {
+	{ OPAL_SENSOR_GROUP_CLEAR, "clear", sg_store },
+};
+
+static void add_attr(int handle, struct sg_attr *attr, int index)
+{
+	attr->handle = handle;
+	sysfs_attr_init(&attr->attr.attr);
+	attr->attr.attr.name = ops_info[index].attr_name;
+	attr->attr.attr.mode = 0220;
+	attr->attr.store = ops_info[index].store;
+}
+
+static int add_attr_group(const __be32 *ops, int len, struct sensor_group *sg,
+			   u32 handle)
+{
+	int i, j;
+	int count = 0;
+
+	for (i = 0; i < len; i++)
+		for (j = 0; j < ARRAY_SIZE(ops_info); j++)
+			if (be32_to_cpu(ops[i]) == ops_info[j].opal_no) {
+				add_attr(handle, &sg->sgattrs[count], j);
+				sg->sg.attrs[count] =
+					&sg->sgattrs[count].attr.attr;
+				count++;
+			}
+
+	return sysfs_create_group(sg_kobj, &sg->sg);
+}
+
+static int get_nr_attrs(const __be32 *ops, int len)
+{
+	int i, j;
+	int nr_attrs = 0;
+
+	for (i = 0; i < len; i++)
+		for (j = 0; j < ARRAY_SIZE(ops_info); j++)
+			if (be32_to_cpu(ops[i]) == ops_info[j].opal_no)
+				nr_attrs++;
+
+	return nr_attrs;
+}
+
+void __init opal_sensor_groups_init(void)
+{
+	struct device_node *sg, *node;
+	int i = 0;
+
+	sg = of_find_compatible_node(NULL, NULL, "ibm,opal-sensor-group");
+	if (!sg) {
+		pr_devel("Sensor groups node not found\n");
+		return;
+	}
+
+	sgs = kcalloc(of_get_child_count(sg), sizeof(*sgs), GFP_KERNEL);
+	if (!sgs)
+		return;
+
+	sg_kobj = kobject_create_and_add("sensor_groups", opal_kobj);
+	if (!sg_kobj) {
+		pr_warn("Failed to create sensor group kobject\n");
+		goto out_sgs;
+	}
+
+	for_each_child_of_node(sg, node) {
+		const __be32 *ops;
+		u32 sgid, len, nr_attrs, chipid;
+
+		ops = of_get_property(node, "ops", &len);
+		if (!ops)
+			continue;
+
+		nr_attrs = get_nr_attrs(ops, len);
+		if (!nr_attrs)
+			continue;
+
+		sgs[i].sgattrs = kcalloc(nr_attrs, sizeof(struct sg_attr),
+					 GFP_KERNEL);
+		if (!sgs[i].sgattrs)
+			goto out_sgs_sgattrs;
+
+		sgs[i].sg.attrs = kcalloc(nr_attrs + 1,
+					  sizeof(struct attribute *),
+					  GFP_KERNEL);
+
+		if (!sgs[i].sg.attrs) {
+			kfree(sgs[i].sgattrs);
+			goto out_sgs_sgattrs;
+		}
+
+		if (of_property_read_u32(node, "sensor-group-id", &sgid)) {
+			pr_warn("sensor-group-id property not found\n");
+			goto out_sgs_sgattrs;
+		}
+
+		if (!of_property_read_u32(node, "ibm,chip-id", &chipid))
+			sprintf(sgs[i].name, "%s%d", node->name, chipid);
+		else
+			sprintf(sgs[i].name, "%s", node->name);
+
+		sgs[i].sg.name = sgs[i].name;
+		if (add_attr_group(ops, len, &sgs[i], sgid)) {
+			pr_warn("Failed to create sensor attribute group %s\n",
+				sgs[i].sg.name);
+			goto out_sgs_sgattrs;
+		}
+		i++;
+	}
+
+	return;
+
+out_sgs_sgattrs:
+	while (--i >= 0) {
+		kfree(sgs[i].sgattrs);
+		kfree(sgs[i].sg.attrs);
+	}
+	kobject_put(sg_kobj);
+out_sgs:
+	kfree(sgs);
+}

arch/powerpc/platforms/powernv/opal-wrappers.S

@@ -318,3 +318,4 @@ OPAL_CALL(opal_get_powercap,			OPAL_GET_POWERCAP);
 OPAL_CALL(opal_set_powercap,			OPAL_SET_POWERCAP);
 OPAL_CALL(opal_get_power_shift_ratio,		OPAL_GET_POWER_SHIFT_RATIO);
 OPAL_CALL(opal_set_power_shift_ratio,		OPAL_SET_POWER_SHIFT_RATIO);
+OPAL_CALL(opal_sensor_group_clear,		OPAL_SENSOR_GROUP_CLEAR);

arch/powerpc/platforms/powernv/opal.c

@@ -856,6 +856,9 @@ static int __init opal_init(void)
 	/* Initialise OPAL Power-Shifting-Ratio interface */
 	opal_psr_init();
 
+	/* Initialise OPAL sensor groups */
+	opal_sensor_groups_init();
+
 	return 0;
 }
 machine_subsys_initcall(powernv, opal_init);