On Mon, 2017-07-31 at 07:54 +0530, Shilpasri G Bhat wrote:
> Adds a generic powercap framework to change the system powercap
> inband through OPAL-OCC command/response interface.
>
> 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 | 5 +-
> arch/powerpc/include/asm/opal.h | 4 +
> arch/powerpc/platforms/powernv/Makefile | 2 +-
> arch/powerpc/platforms/powernv/opal-powercap.c | 243
> +++++++++++++++++++++++++
> arch/powerpc/platforms/powernv/opal-wrappers.S | 2 +
> arch/powerpc/platforms/powernv/opal.c | 4 +
> 6 files changed, 258 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..9be5093
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/opal-powercap.c
> @@ -0,0 +1,243 @@
> +/*
> + * 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 pcap {
> + struct attribute_group pg;
> + struct powercap_attr *pattrs;
> +} *pcaps;
> +
> +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;
> + }
> +
> + ret = mutex_lock_interruptible(&powercap_mutex);
> + if (ret)
You'll need to release the token here.
> + return ret;
> +
> + ret = opal_get_powercap(pcap_attr->handle, token, (u32 *)__pa(&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\n");
> + ret = -EIO;
> + goto out;
> + }
> + ret = opal_error_code(opal_get_async_rc(msg));
> + if (!ret) {
> + ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
> + if (ret < 0)
> + ret = -EIO;
> + }
> + break;
> + case OPAL_SUCCESS:
> + ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
> + if (ret < 0)
> + ret = -EIO;
> + 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;
> + }
> +
> + ret = mutex_lock_interruptible(&powercap_mutex);
> + if (ret)
You'll need to release the token here.
> + return ret;
> +
> + 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\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(&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 i = 0;
> +
> + powercap = of_find_compatible_node(NULL, NULL, "ibm,opal-powercap");
> + if (!powercap) {
> + pr_devel("Powercap node not found\n");
> + return;
> + }
> +
> + pcaps = kcalloc(of_get_child_count(powercap), sizeof(*pcaps),
> + GFP_KERNEL);
> + if (!pcaps)
> + return;
> +
> + powercap_kobj = kobject_create_and_add("powercap", opal_kobj);
> + if (!powercap_kobj) {
> + pr_warn("Failed to create powercap kobject\n");
> + goto out_pcaps;
> + }
> +
> + i = 0;
> + for_each_child_of_node(powercap, node) {
> + u32 cur, min, max;
> + int j = 0;
> + bool has_cur = false, has_min = false, has_max = false;
> +
> + if (!of_property_read_u32(node, "powercap-min", &min)) {
> + j++;
> + has_min = true;
> + }
> +
> + if (!of_property_read_u32(node, "powercap-max", &max)) {
> + j++;
> + has_max = true;
> + }
> +
> + if (!of_property_read_u32(node, "powercap-current", &cur)) {
> + j++;
> + has_cur = true;
> + }
> +
> + pcaps[i].pattrs = kcalloc(j, sizeof(struct powercap_attr),
> + GFP_KERNEL);
> + if (!pcaps[i].pattrs)
> + goto out_pcaps_pattrs;
> +
> + pcaps[i].pg.attrs = kcalloc(j + 1, sizeof(struct attribute *),
> + GFP_KERNEL);
> + if (!pcaps[i].pg.attrs) {
> + kfree(pcaps[i].pattrs);
> + goto out_pcaps_pattrs;
> + }
> +
> + j = 0;
> + pcaps[i].pg.name = node->name;
> + if (has_min) {
> + powercap_add_attr(min, "powercap-min",
> + &pcaps[i].pattrs[j]);
> + pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
> + j++;
> + }
> +
> + if (has_max) {
> + powercap_add_attr(max, "powercap-max",
> + &pcaps[i].pattrs[j]);
> + pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
> + j++;
> + }
> +
> + if (has_cur) {
> + powercap_add_attr(cur, "powercap-current",
> + &pcaps[i].pattrs[j]);
> + pcaps[i].pattrs[j].attr.attr.mode |= 0220;
> + pcaps[i].pattrs[j].attr.store = powercap_store;
> + pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
> + j++;
> + }
> +
> + if (sysfs_create_group(powercap_kobj, &pcaps[i].pg)) {
> + pr_warn("Failed to create powercap attribute group
> %s\n",
> + pcaps[i].pg.name);
> + goto out_pcaps_pattrs;
> + }
> + i++;
> + }
> +
> + return;
> +
> +out_pcaps_pattrs:
> + while (--i >= 0) {
> + kfree(pcaps[i].pattrs);
> + kfree(pcaps[i].pg.attrs);
> + }
> + kobject_put(powercap_kobj);
> +out_pcaps:
> + kfree(pcaps);
> +}
> 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;
