This patch adds support to set power-shifting-ratio which hints the
firmware how to distribute/throttle power between different entities
in a system (e.g CPU v/s GPU). This ratio is used by OCC for power
capping algorithm.
Signed-off-by: Shilpasri G Bhat <shilpa.b...@linux.vnet.ibm.com>
---
Changes from V8:
- Use __pa() while passing pointer in opal call
- Use mutex_lock_interruptible()
- Fix error codes returned to user
- Allocate and add sysfs attributes in a single loop
arch/powerpc/include/asm/opal-api.h | 4 +-
arch/powerpc/include/asm/opal.h | 3 +
arch/powerpc/platforms/powernv/Makefile | 2 +-
arch/powerpc/platforms/powernv/opal-psr.c | 173 +++++++++++++++++++++++++
arch/powerpc/platforms/powernv/opal-wrappers.S | 2 +
arch/powerpc/platforms/powernv/opal.c | 3 +
6 files changed, 185 insertions(+), 2 deletions(-)
create mode 100644 arch/powerpc/platforms/powernv/opal-psr.c
diff --git a/arch/powerpc/include/asm/opal-api.h
b/arch/powerpc/include/asm/opal-api.h
index c3e0c4a..92e31fd 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -193,7 +193,9 @@
#define OPAL_NPU_MAP_LPAR 148
#define OPAL_GET_POWERCAP 152
#define OPAL_SET_POWERCAP 153
-#define OPAL_LAST 153
+#define OPAL_GET_POWER_SHIFT_RATIO 154
+#define OPAL_SET_POWER_SHIFT_RATIO 155
+#define OPAL_LAST 155
/* Device tree flags */
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index ec2087c..b9ea77f 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -269,6 +269,8 @@ int64_t opal_xive_set_vp_info(uint64_t vp,
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);
+int opal_get_power_shift_ratio(u32 handle, int token, u32 *psr);
+int opal_set_power_shift_ratio(u32 handle, int token, u32 psr);
/* Internal functions */
extern int early_init_dt_scan_opal(unsigned long node, const char *uname,
@@ -348,6 +350,7 @@ static inline int opal_get_async_rc(struct opal_msg msg)
void opal_wake_poller(void);
void opal_powercap_init(void);
+void opal_psr_init(void);
#endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/platforms/powernv/Makefile
b/arch/powerpc/platforms/powernv/Makefile
index e79f806..9ed7d33 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 opal-powercap.o
+obj-y += opal-kmsg.o opal-powercap.o opal-psr.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-psr.c
b/arch/powerpc/platforms/powernv/opal-psr.c
new file mode 100644
index 0000000..e2cb335
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-psr.c
@@ -0,0 +1,173 @@
+/*
+ * PowerNV OPAL Power-Shift-Ratio 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-psr: " fmt
+
+#include <linux/of.h>
+#include <linux/kobject.h>
+#include <linux/slab.h>
+
+#include <asm/opal.h>
+
+DEFINE_MUTEX(psr_mutex);
+
+static struct kobject *psr_kobj;
+
+struct psr_attr {
+ u32 handle;
+ struct kobj_attribute attr;
+} *psr_attrs;
+
+static ssize_t psr_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr);
+ struct opal_msg msg;
+ int psr, ret, token;
+
+ token = opal_async_get_token_interruptible();
+ if (token < 0) {
+ pr_devel("Failed to get token\n");
+ return token;
+ }
+
+ ret = mutex_lock_interruptible(&psr_mutex);
+ if (ret)
+ return ret;
+
+ ret = opal_get_power_shift_ratio(psr_attr->handle, token,
+ (u32 *)__pa(&psr));
+ 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 = sprintf(buf, "%u\n", be32_to_cpu(psr));
+ if (ret < 0)
+ ret = -EIO;
+ }
+ break;
+ case OPAL_SUCCESS:
+ ret = sprintf(buf, "%u\n", be32_to_cpu(psr));
+ if (ret < 0)
+ ret = -EIO;
+ break;
+ default:
+ ret = opal_error_code(ret);
+ }
+
+out:
+ mutex_unlock(&psr_mutex);
+ opal_async_release_token(token);
+ return ret;
+}
+
+static ssize_t psr_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr);
+ struct opal_msg msg;
+ int psr, ret, token;
+
+ ret = kstrtoint(buf, 0, &psr);
+ if (ret)
+ return ret;
+
+ token = opal_async_get_token_interruptible();
+ if (token < 0) {
+ pr_devel("Failed to get token\n");
+ return token;
+ }
+
+ ret = mutex_lock_interruptible(&psr_mutex);
+ if (ret)
+ return ret;
+
+ ret = opal_set_power_shift_ratio(psr_attr->handle, token, psr);
+ 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(&psr_mutex);
+ opal_async_release_token(token);
+ return ret;
+}
+
+void __init opal_psr_init(void)
+{
+ struct device_node *psr, *node;
+ int i = 0;
+
+ psr = of_find_compatible_node(NULL, NULL,
+ "ibm,opal-power-shift-ratio");
+ if (!psr) {
+ pr_devel("Power-shift-ratio node not found\n");
+ return;
+ }
+
+ psr_attrs = kcalloc(of_get_child_count(psr), sizeof(struct psr_attr),
+ GFP_KERNEL);
+ if (!psr_attrs)
+ return;
+
+ psr_kobj = kobject_create_and_add("psr", opal_kobj);
+ if (!psr_kobj) {
+ pr_warn("Failed to create psr kobject\n");
+ goto out;
+ }
+
+ for_each_child_of_node(psr, node) {
+ if (of_property_read_u32(node, "handle",
+ &psr_attrs[i].handle))
+ goto out_kobj;
+
+ sysfs_attr_init(&psr_attrs[i].attr.attr);
+ if (of_property_read_string(node, "label",
+ &psr_attrs[i].attr.attr.name))
+ goto out_kobj;
+ psr_attrs[i].attr.attr.mode = 0664;
+ psr_attrs[i].attr.show = psr_show;
+ psr_attrs[i].attr.store = psr_store;
+ if (sysfs_create_file(psr_kobj, &psr_attrs[i].attr.attr)) {
+ pr_devel("Failed to create psr sysfs file %s\n",
+ psr_attrs[i].attr.attr.name);
+ goto out_kobj;
+ }
+ i++;
+ }
+
+ return;
+out_kobj:
+ kobject_put(psr_kobj);
+out:
+ kfree(psr_attrs);
+}
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S
b/arch/powerpc/platforms/powernv/opal-wrappers.S
index eff5fe7..f565979 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -312,3 +312,5 @@ 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);
+OPAL_CALL(opal_get_power_shift_ratio, OPAL_GET_POWER_SHIFT_RATIO);
+OPAL_CALL(opal_set_power_shift_ratio, OPAL_SET_POWER_SHIFT_RATIO);
diff --git a/arch/powerpc/platforms/powernv/opal.c
b/arch/powerpc/platforms/powernv/opal.c
index 889da97..280a736 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -839,6 +839,9 @@ static int __init opal_init(void)
/* Initialise OPAL powercap interface */
opal_powercap_init();
+ /* Initialise OPAL Power-Shifting-Ratio interface */
+ opal_psr_init();
+
return 0;
}
machine_subsys_initcall(powernv, opal_init);
--
1.8.3.1
