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Release 4.14 arch/powerpc/platforms/pseries/pseries_energy.c

/*
 * POWER platform energy management driver
 * Copyright (C) 2010 IBM Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This pseries platform device driver provides access to
 * platform energy management capabilities.
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/device.h>
#include <linux/cpu.h>
#include <linux/of.h>
#include <asm/cputhreads.h>
#include <asm/page.h>
#include <asm/hvcall.h>
#include <asm/firmware.h>



#define MODULE_VERS "1.0"

#define MODULE_NAME "pseries_energy"

/* Driver flags */


static int sysfs_entries;

/* Helper routines */

/* Helper Routines to convert between drc_index to cpu numbers */


static u32 cpu_to_drc_index(int cpu) { struct device_node *dn = NULL; const int *indexes; int i; int rc = 1; u32 ret = 0; dn = of_find_node_by_path("/cpus"); if (dn == NULL) goto err; indexes = of_get_property(dn, "ibm,drc-indexes", NULL); if (indexes == NULL) goto err_of_node_put; /* Convert logical cpu number to core number */ i = cpu_core_index_of_thread(cpu); /* * The first element indexes[0] is the number of drc_indexes * returned in the list. Hence i+1 will get the drc_index * corresponding to core number i. */ WARN_ON(i > indexes[0]); ret = indexes[i + 1]; rc = 0; err_of_node_put: of_node_put(dn); err: if (rc) printk(KERN_WARNING "cpu_to_drc_index(%d) failed", cpu); return ret; }

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Vaidyanathan Srinivasan126100.00%1100.00%
Total126100.00%1100.00%


static int drc_index_to_cpu(u32 drc_index) { struct device_node *dn = NULL; const int *indexes; int i, cpu = 0; int rc = 1; dn = of_find_node_by_path("/cpus"); if (dn == NULL) goto err; indexes = of_get_property(dn, "ibm,drc-indexes", NULL); if (indexes == NULL) goto err_of_node_put; /* * First element in the array is the number of drc_indexes * returned. Search through the list to find the matching * drc_index and get the core number */ for (i = 0; i < indexes[0]; i++) { if (indexes[i + 1] == drc_index) break; } /* Convert core number to logical cpu number */ cpu = cpu_first_thread_of_core(i); rc = 0; err_of_node_put: of_node_put(dn); err: if (rc) printk(KERN_WARNING "drc_index_to_cpu(%d) failed", drc_index); return cpu; }

Contributors

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Vaidyanathan Srinivasan136100.00%1100.00%
Total136100.00%1100.00%

/* * pseries hypervisor call H_BEST_ENERGY provides hints to OS on * preferred logical cpus to activate or deactivate for optimized * energy consumption. */ #define FLAGS_MODE1 0x004E200000080E01UL #define FLAGS_MODE2 0x004E200000080401UL #define FLAGS_ACTIVATE 0x100
static ssize_t get_best_energy_list(char *page, int activate) { int rc, cnt, i, cpu; unsigned long retbuf[PLPAR_HCALL9_BUFSIZE]; unsigned long flags = 0; u32 *buf_page; char *s = page; buf_page = (u32 *) get_zeroed_page(GFP_KERNEL); if (!buf_page) return -ENOMEM; flags = FLAGS_MODE1; if (activate) flags |= FLAGS_ACTIVATE; rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags, 0, __pa(buf_page), 0, 0, 0, 0, 0, 0); if (rc != H_SUCCESS) { free_page((unsigned long) buf_page); return -EINVAL; } cnt = retbuf[0]; for (i = 0; i < cnt; i++) { cpu = drc_index_to_cpu(buf_page[2*i+1]); if ((cpu_online(cpu) && !activate) || (!cpu_online(cpu) && activate)) s += sprintf(s, "%d,", cpu); } if (s > page) { /* Something to show */ s--; /* Suppress last comma */ s += sprintf(s, "\n"); } free_page((unsigned long) buf_page); return s-page; }

Contributors

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Vaidyanathan Srinivasan233100.00%1100.00%
Total233100.00%1100.00%


static ssize_t get_best_energy_data(struct device *dev, char *page, int activate) { int rc; unsigned long retbuf[PLPAR_HCALL9_BUFSIZE]; unsigned long flags = 0; flags = FLAGS_MODE2; if (activate) flags |= FLAGS_ACTIVATE; rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags, cpu_to_drc_index(dev->id), 0, 0, 0, 0, 0, 0, 0); if (rc != H_SUCCESS) return -EINVAL; return sprintf(page, "%lu\n", retbuf[1] >> 32); }

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Vaidyanathan Srinivasan10299.03%150.00%
Kay Sievers10.97%150.00%
Total103100.00%2100.00%

/* Wrapper functions */
static ssize_t cpu_activate_hint_list_show(struct device *dev, struct device_attribute *attr, char *page) { return get_best_energy_list(page, 1); }

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PersonTokensPropCommitsCommitProp
Vaidyanathan Srinivasan2589.29%150.00%
Kay Sievers310.71%150.00%
Total28100.00%2100.00%


static ssize_t cpu_deactivate_hint_list_show(struct device *dev, struct device_attribute *attr, char *page) { return get_best_energy_list(page, 0); }

Contributors

PersonTokensPropCommitsCommitProp
Vaidyanathan Srinivasan2589.29%150.00%
Kay Sievers310.71%150.00%
Total28100.00%2100.00%


static ssize_t percpu_activate_hint_show(struct device *dev, struct device_attribute *attr, char *page) { return get_best_energy_data(dev, page, 1); }

Contributors

PersonTokensPropCommitsCommitProp
Vaidyanathan Srinivasan2893.33%150.00%
Kay Sievers26.67%150.00%
Total30100.00%2100.00%


static ssize_t percpu_deactivate_hint_show(struct device *dev, struct device_attribute *attr, char *page) { return get_best_energy_data(dev, page, 0); }

Contributors

PersonTokensPropCommitsCommitProp
Vaidyanathan Srinivasan2893.33%150.00%
Kay Sievers26.67%150.00%
Total30100.00%2100.00%

/* * Create sysfs interface: * /sys/devices/system/cpu/pseries_activate_hint_list * /sys/devices/system/cpu/pseries_deactivate_hint_list * Comma separated list of cpus to activate or deactivate * /sys/devices/system/cpu/cpuN/pseries_activate_hint * /sys/devices/system/cpu/cpuN/pseries_deactivate_hint * Per-cpu value of the hint */ static struct device_attribute attr_cpu_activate_hint_list = __ATTR(pseries_activate_hint_list, 0444, cpu_activate_hint_list_show, NULL); static struct device_attribute attr_cpu_deactivate_hint_list = __ATTR(pseries_deactivate_hint_list, 0444, cpu_deactivate_hint_list_show, NULL); static struct device_attribute attr_percpu_activate_hint = __ATTR(pseries_activate_hint, 0444, percpu_activate_hint_show, NULL); static struct device_attribute attr_percpu_deactivate_hint = __ATTR(pseries_deactivate_hint, 0444, percpu_deactivate_hint_show, NULL);
static int __init pseries_energy_init(void) { int cpu, err; struct device *cpu_dev; if (!firmware_has_feature(FW_FEATURE_BEST_ENERGY)) return 0; /* H_BEST_ENERGY hcall not supported */ /* Create the sysfs files */ err = device_create_file(cpu_subsys.dev_root, &attr_cpu_activate_hint_list); if (!err) err = device_create_file(cpu_subsys.dev_root, &attr_cpu_deactivate_hint_list); if (err) return err; for_each_possible_cpu(cpu) { cpu_dev = get_cpu_device(cpu); err = device_create_file(cpu_dev, &attr_percpu_activate_hint); if (err) break; err = device_create_file(cpu_dev, &attr_percpu_deactivate_hint); if (err) break; } if (err) return err; sysfs_entries = 1; /* Removed entries on cleanup */ return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Vaidyanathan Srinivasan10784.92%125.00%
Kay Sievers1411.11%125.00%
Michael Neuling43.17%125.00%
Nicholas Piggin10.79%125.00%
Total126100.00%4100.00%


static void __exit pseries_energy_cleanup(void) { int cpu; struct device *cpu_dev; if (!sysfs_entries) return; /* Remove the sysfs files */ device_remove_file(cpu_subsys.dev_root, &attr_cpu_activate_hint_list); device_remove_file(cpu_subsys.dev_root, &attr_cpu_deactivate_hint_list); for_each_possible_cpu(cpu) { cpu_dev = get_cpu_device(cpu); sysfs_remove_file(&cpu_dev->kobj, &attr_percpu_activate_hint.attr); sysfs_remove_file(&cpu_dev->kobj, &attr_percpu_deactivate_hint.attr); } }

Contributors

PersonTokensPropCommitsCommitProp
Vaidyanathan Srinivasan7185.54%150.00%
Kay Sievers1214.46%150.00%
Total83100.00%2100.00%

module_init(pseries_energy_init); module_exit(pseries_energy_cleanup); MODULE_DESCRIPTION("Driver for pSeries platform energy management"); MODULE_AUTHOR("Vaidyanathan Srinivasan"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Vaidyanathan Srinivasan101994.44%116.67%
Kay Sievers464.26%116.67%
Michael Neuling70.65%116.67%
Daniel Axtens40.37%116.67%
Anton Blanchard20.19%116.67%
Nicholas Piggin10.09%116.67%
Total1079100.00%6100.00%
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