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Commit cb8b340d authored by Shilpasri G Bhat's avatar Shilpasri G Bhat Committed by Michael Ellerman
Browse files

powerpc/powernv: Add support for powercap framework 



Adds a generic powercap framework to change the system powercap
inband through OPAL-OCC command/response interface.

Signed-off-by: default avatarShilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent a70a0b9f

Documentation/ABI/testing/sysfs-firmware-opal-powercap

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+31 −0
Original line number Diff line number Diff line 
What:		/sys/firmware/opal/powercap

Date:		August 2017

Contact:	Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>

Description:	Powercap directory for Powernv (P8, P9) servers



		Each folder in this directory contains a

		power-cappable component.



What:		/sys/firmware/opal/powercap/system-powercap

		/sys/firmware/opal/powercap/system-powercap/powercap-min

		/sys/firmware/opal/powercap/system-powercap/powercap-max

		/sys/firmware/opal/powercap/system-powercap/powercap-current

Date:		August 2017

Contact:	Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>

Description:	System powercap directory and attributes applicable for

		Powernv (P8, P9) servers



		This directory provides powercap information. It

		contains below sysfs attributes:



		- powercap-min : This file provides the minimum

		  possible powercap in Watt units



		- powercap-max : This file provides the maximum

		  possible powercap in Watt units



		- powercap-current : This file provides the current

		  powercap set on the system. Writing to this file

		  creates a request for setting a new-powercap. The

		  powercap requested must be between powercap-min

		  and powercap-max.

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

+3 −0
Original line number Diff line number Diff line
@@ -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
@@ -193,6 +194,8 @@ 
#define OPAL_IMC_COUNTERS_INIT			149

#define OPAL_IMC_COUNTERS_START			150

#define OPAL_IMC_COUNTERS_STOP			151

#define OPAL_GET_POWERCAP			152

#define OPAL_SET_POWERCAP			153

#define OPAL_PCI_SET_P2P			157

#define OPAL_LAST				157

arch/powerpc/include/asm/opal.h

+5 −0
Original line number Diff line number Diff line
@@ -275,6 +275,9 @@ int64_t opal_imc_counters_init(uint32_t type, uint64_t address, 
int64_t opal_imc_counters_start(uint32_t type, uint64_t cpu_pir);

int64_t opal_imc_counters_stop(uint32_t type, uint64_t cpu_pir);



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,

				   int depth, void *data);
@@ -352,6 +355,8 @@ 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 */

arch/powerpc/platforms/powernv/Makefile

+1 −1
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@@ -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

arch/powerpc/platforms/powernv/opal-powercap.c

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+244 −0
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/*

 * 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)

		goto out_token;



	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);

out_token:

	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)

		goto out_token;



	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);

out_token:

	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);

}