[PATCH V8 1/3] powernv: powercap: Add support for powercap framework
From: Shilpasri G Bhat
Date: Wed Jul 26 2017 - 01:05:33 EST
Adds a generic powercap framework to change the system powercap
inband through OPAL-OCC command/response interface.
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@xxxxxxxxxxxxxxxxxx>
---
Changes from V7:
- Replaced sscanf with kstrtoint
arch/powerpc/include/asm/opal-api.h | 5 +-
arch/powerpc/include/asm/opal.h | 4 +
arch/powerpc/platforms/powernv/Makefile | 2 +-
arch/powerpc/platforms/powernv/opal-powercap.c | 237 +++++++++++++++++++++++++
arch/powerpc/platforms/powernv/opal-wrappers.S | 2 +
arch/powerpc/platforms/powernv/opal.c | 4 +
6 files changed, 252 insertions(+), 2 deletions(-)
create mode 100644 arch/powerpc/platforms/powernv/opal-powercap.c
diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 3130a73..c3e0c4a 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -42,6 +42,7 @@
#define OPAL_I2C_STOP_ERR -24
#define OPAL_XIVE_PROVISIONING -31
#define OPAL_XIVE_FREE_ACTIVE -32
+#define OPAL_TIMEOUT -33
/* API Tokens (in r0) */
#define OPAL_INVALID_CALL -1
@@ -190,7 +191,9 @@
#define OPAL_NPU_INIT_CONTEXT 146
#define OPAL_NPU_DESTROY_CONTEXT 147
#define OPAL_NPU_MAP_LPAR 148
-#define OPAL_LAST 148
+#define OPAL_GET_POWERCAP 152
+#define OPAL_SET_POWERCAP 153
+#define OPAL_LAST 153
/* Device tree flags */
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 588fb1c..ec2087c 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -267,6 +267,8 @@ int64_t opal_xive_set_vp_info(uint64_t vp,
int64_t opal_xive_free_irq(uint32_t girq);
int64_t opal_xive_sync(uint32_t type, uint32_t id);
int64_t opal_xive_dump(uint32_t type, uint32_t id);
+int opal_get_powercap(u32 handle, int token, u32 *pcap);
+int opal_set_powercap(u32 handle, int token, u32 pcap);
/* Internal functions */
extern int early_init_dt_scan_opal(unsigned long node, const char *uname,
@@ -345,6 +347,8 @@ static inline int opal_get_async_rc(struct opal_msg msg)
void opal_wake_poller(void);
+void opal_powercap_init(void);
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_OPAL_H */
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index b5d98cb..e79f806 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/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
+obj-y += opal-kmsg.o opal-powercap.o
obj-$(CONFIG_SMP) += smp.o subcore.o subcore-asm.o
obj-$(CONFIG_PCI) += pci.o pci-ioda.o npu-dma.o
diff --git a/arch/powerpc/platforms/powernv/opal-powercap.c b/arch/powerpc/platforms/powernv/opal-powercap.c
new file mode 100644
index 0000000..7c57f4b
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-powercap.c
@@ -0,0 +1,237 @@
+/*
+ * PowerNV OPAL Powercap 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-powercap: " fmt
+
+#include <linux/of.h>
+#include <linux/kobject.h>
+#include <linux/slab.h>
+
+#include <asm/opal.h>
+
+DEFINE_MUTEX(powercap_mutex);
+
+static struct kobject *powercap_kobj;
+
+struct powercap_attr {
+ u32 handle;
+ struct kobj_attribute attr;
+};
+
+static struct attribute_group *pattr_groups;
+static struct powercap_attr *pcap_attrs;
+
+static ssize_t powercap_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ struct powercap_attr *pcap_attr = container_of(attr,
+ struct powercap_attr, attr);
+ struct opal_msg msg;
+ u32 pcap;
+ int ret, token;
+
+ token = opal_async_get_token_interruptible();
+ if (token < 0) {
+ pr_devel("Failed to get token\n");
+ return token;
+ }
+
+ mutex_lock(&powercap_mutex);
+ ret = opal_get_powercap(pcap_attr->handle, token, &pcap);
+ switch (ret) {
+ case OPAL_ASYNC_COMPLETION:
+ ret = opal_async_wait_response(token, &msg);
+ if (ret) {
+ pr_devel("Failed to wait for the async response %d\n",
+ ret);
+ goto out;
+ }
+ ret = opal_error_code(opal_get_async_rc(msg));
+ if (!ret)
+ ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
+ break;
+ case OPAL_SUCCESS:
+ ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
+ break;
+ default:
+ ret = opal_error_code(ret);
+ }
+
+out:
+ mutex_unlock(&powercap_mutex);
+ opal_async_release_token(token);
+ return ret;
+}
+
+static ssize_t powercap_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct powercap_attr *pcap_attr = container_of(attr,
+ struct powercap_attr, attr);
+ struct opal_msg msg;
+ u32 pcap;
+ int ret, token;
+
+ ret = kstrtoint(buf, 0, &pcap);
+ if (ret)
+ return ret;
+
+ token = opal_async_get_token_interruptible();
+ if (token < 0) {
+ pr_devel("Failed to get token\n");
+ return token;
+ }
+
+ mutex_lock(&powercap_mutex);
+ ret = opal_set_powercap(pcap_attr->handle, token, pcap);
+ switch (ret) {
+ case OPAL_ASYNC_COMPLETION:
+ ret = opal_async_wait_response(token, &msg);
+ if (ret) {
+ pr_devel("Failed to wait for the async response %d\n",
+ ret);
+ 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(&powercap_mutex);
+ opal_async_release_token(token);
+
+ return ret;
+}
+
+static void powercap_add_attr(int handle, const char *name,
+ struct powercap_attr *attr)
+{
+ attr->handle = handle;
+ sysfs_attr_init(&attr->attr.attr);
+ attr->attr.attr.name = name;
+ attr->attr.attr.mode = 0444;
+ attr->attr.show = powercap_show;
+}
+
+void __init opal_powercap_init(void)
+{
+ struct device_node *powercap, *node;
+ int pattr_group_count = 0, total_attr_count = 0;
+ int i, count;
+
+ powercap = of_find_node_by_path("/ibm,opal/power-mgt/powercap");
+ if (!powercap) {
+ pr_devel("/ibm,opal/power-mgt/powercap node not found\n");
+ return;
+ }
+
+ for_each_child_of_node(powercap, node)
+ pattr_group_count++;
+
+ pattr_groups = kcalloc(pattr_group_count,
+ sizeof(struct attribute_group), GFP_KERNEL);
+ if (!pattr_groups)
+ return;
+
+ i = 0;
+ for_each_child_of_node(powercap, node) {
+ int attr_count = 0;
+
+ if (of_find_property(node, "powercap-min", NULL))
+ attr_count++;
+ if (of_find_property(node, "powercap-max", NULL))
+ attr_count++;
+ if (of_find_property(node, "powercap-cur", NULL))
+ attr_count++;
+
+ total_attr_count += attr_count;
+ pattr_groups[i].attrs = kcalloc(attr_count + 1,
+ sizeof(struct attribute *),
+ GFP_KERNEL);
+ if (!pattr_groups[i].attrs) {
+ while (--i >= 0)
+ kfree(pattr_groups[i].attrs);
+ goto out_pattr_groups;
+ }
+ i++;
+ }
+
+ pcap_attrs = kcalloc(total_attr_count, sizeof(struct powercap_attr),
+ GFP_KERNEL);
+ if (!pcap_attrs)
+ goto out_pattr_groups_attrs;
+
+ count = 0;
+ i = 0;
+ for_each_child_of_node(powercap, node) {
+ u32 handle;
+ int j = 0;
+
+ pattr_groups[i].name = node->name;
+
+ if (!of_property_read_u32(node, "powercap-min", &handle)) {
+ powercap_add_attr(handle, "powercap-min",
+ &pcap_attrs[count]);
+ pattr_groups[i].attrs[j++] =
+ &pcap_attrs[count++].attr.attr;
+ }
+
+ if (!of_property_read_u32(node, "powercap-max", &handle)) {
+ powercap_add_attr(handle, "powercap-max",
+ &pcap_attrs[count]);
+ pattr_groups[i].attrs[j++] =
+ &pcap_attrs[count++].attr.attr;
+ }
+
+ if (!of_property_read_u32(node, "powercap-cur", &handle)) {
+ powercap_add_attr(handle, "powercap-cur",
+ &pcap_attrs[count]);
+ pcap_attrs[count].attr.attr.mode |= 0220;
+ pcap_attrs[count].attr.store = powercap_store;
+ pattr_groups[i].attrs[j++] =
+ &pcap_attrs[count++].attr.attr;
+ }
+ i++;
+ }
+
+ powercap_kobj = kobject_create_and_add("powercap", opal_kobj);
+ if (!powercap_kobj) {
+ pr_warn("Failed to create powercap kobject\n");
+ goto out_pcap_attrs;
+ }
+
+ for (i = 0; i < pattr_group_count; i++) {
+ if (sysfs_create_group(powercap_kobj, &pattr_groups[i])) {
+ pr_warn("Failed to create powercap attribute group %s\n",
+ pattr_groups[i].name);
+ goto out;
+ }
+ }
+
+ return;
+out:
+ kobject_put(powercap_kobj);
+out_pcap_attrs:
+ kfree(pcap_attrs);
+out_pattr_groups_attrs:
+ while (--pattr_group_count >= 0)
+ kfree(pattr_groups[i].attrs);
+out_pattr_groups:
+ kfree(pattr_groups);
+}
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index 4ca6c26..eff5fe7 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -310,3 +310,5 @@ OPAL_CALL(opal_xive_dump, OPAL_XIVE_DUMP);
OPAL_CALL(opal_npu_init_context, OPAL_NPU_INIT_CONTEXT);
OPAL_CALL(opal_npu_destroy_context, OPAL_NPU_DESTROY_CONTEXT);
OPAL_CALL(opal_npu_map_lpar, OPAL_NPU_MAP_LPAR);
+OPAL_CALL(opal_get_powercap, OPAL_GET_POWERCAP);
+OPAL_CALL(opal_set_powercap, OPAL_SET_POWERCAP);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index cad6b57..889da97 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -836,6 +836,9 @@ static int __init opal_init(void)
/* Initialise OPAL kmsg dumper for flushing console on panic */
opal_kmsg_init();
+ /* Initialise OPAL powercap interface */
+ opal_powercap_init();
+
return 0;
}
machine_subsys_initcall(powernv, opal_init);
@@ -952,6 +955,7 @@ int opal_error_code(int rc)
case OPAL_UNSUPPORTED: return -EIO;
case OPAL_HARDWARE: return -EIO;
case OPAL_INTERNAL_ERROR: return -EIO;
+ case OPAL_TIMEOUT: return -ETIMEDOUT;
default:
pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
return -EIO;
--
1.8.3.1