https://github.com/torvalds/linux
Tip revision: 0477e92881850d44910a7e94fc2c46f96faa131f authored by Linus Torvalds on 06 December 2020, 22:25:12 UTC
Linux 5.10-rc7
Linux 5.10-rc7
Tip revision: 0477e92
intel_rapl_msr.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Intel Running Average Power Limit (RAPL) Driver via MSR interface
* Copyright (c) 2019, Intel Corporation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/log2.h>
#include <linux/bitmap.h>
#include <linux/delay.h>
#include <linux/sysfs.h>
#include <linux/cpu.h>
#include <linux/powercap.h>
#include <linux/suspend.h>
#include <linux/intel_rapl.h>
#include <linux/processor.h>
#include <linux/platform_device.h>
#include <asm/iosf_mbi.h>
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
/* Local defines */
#define MSR_PLATFORM_POWER_LIMIT 0x0000065C
#define MSR_VR_CURRENT_CONFIG 0x00000601
/* private data for RAPL MSR Interface */
static struct rapl_if_priv rapl_msr_priv = {
.reg_unit = MSR_RAPL_POWER_UNIT,
.regs[RAPL_DOMAIN_PACKAGE] = {
MSR_PKG_POWER_LIMIT, MSR_PKG_ENERGY_STATUS, MSR_PKG_PERF_STATUS, 0, MSR_PKG_POWER_INFO },
.regs[RAPL_DOMAIN_PP0] = {
MSR_PP0_POWER_LIMIT, MSR_PP0_ENERGY_STATUS, 0, MSR_PP0_POLICY, 0 },
.regs[RAPL_DOMAIN_PP1] = {
MSR_PP1_POWER_LIMIT, MSR_PP1_ENERGY_STATUS, 0, MSR_PP1_POLICY, 0 },
.regs[RAPL_DOMAIN_DRAM] = {
MSR_DRAM_POWER_LIMIT, MSR_DRAM_ENERGY_STATUS, MSR_DRAM_PERF_STATUS, 0, MSR_DRAM_POWER_INFO },
.regs[RAPL_DOMAIN_PLATFORM] = {
MSR_PLATFORM_POWER_LIMIT, MSR_PLATFORM_ENERGY_STATUS, 0, 0, 0},
.limits[RAPL_DOMAIN_PACKAGE] = 2,
.limits[RAPL_DOMAIN_PLATFORM] = 2,
};
/* Handles CPU hotplug on multi-socket systems.
* If a CPU goes online as the first CPU of the physical package
* we add the RAPL package to the system. Similarly, when the last
* CPU of the package is removed, we remove the RAPL package and its
* associated domains. Cooling devices are handled accordingly at
* per-domain level.
*/
static int rapl_cpu_online(unsigned int cpu)
{
struct rapl_package *rp;
rp = rapl_find_package_domain(cpu, &rapl_msr_priv);
if (!rp) {
rp = rapl_add_package(cpu, &rapl_msr_priv);
if (IS_ERR(rp))
return PTR_ERR(rp);
}
cpumask_set_cpu(cpu, &rp->cpumask);
return 0;
}
static int rapl_cpu_down_prep(unsigned int cpu)
{
struct rapl_package *rp;
int lead_cpu;
rp = rapl_find_package_domain(cpu, &rapl_msr_priv);
if (!rp)
return 0;
cpumask_clear_cpu(cpu, &rp->cpumask);
lead_cpu = cpumask_first(&rp->cpumask);
if (lead_cpu >= nr_cpu_ids)
rapl_remove_package(rp);
else if (rp->lead_cpu == cpu)
rp->lead_cpu = lead_cpu;
return 0;
}
static int rapl_msr_read_raw(int cpu, struct reg_action *ra)
{
u32 msr = (u32)ra->reg;
if (rdmsrl_safe_on_cpu(cpu, msr, &ra->value)) {
pr_debug("failed to read msr 0x%x on cpu %d\n", msr, cpu);
return -EIO;
}
ra->value &= ra->mask;
return 0;
}
static void rapl_msr_update_func(void *info)
{
struct reg_action *ra = info;
u32 msr = (u32)ra->reg;
u64 val;
ra->err = rdmsrl_safe(msr, &val);
if (ra->err)
return;
val &= ~ra->mask;
val |= ra->value;
ra->err = wrmsrl_safe(msr, val);
}
static int rapl_msr_write_raw(int cpu, struct reg_action *ra)
{
int ret;
ret = smp_call_function_single(cpu, rapl_msr_update_func, ra, 1);
if (WARN_ON_ONCE(ret))
return ret;
return ra->err;
}
/* List of verified CPUs. */
static const struct x86_cpu_id pl4_support_ids[] = {
{ X86_VENDOR_INTEL, 6, INTEL_FAM6_TIGERLAKE_L, X86_FEATURE_ANY },
{}
};
static int rapl_msr_probe(struct platform_device *pdev)
{
const struct x86_cpu_id *id = x86_match_cpu(pl4_support_ids);
int ret;
rapl_msr_priv.read_raw = rapl_msr_read_raw;
rapl_msr_priv.write_raw = rapl_msr_write_raw;
if (id) {
rapl_msr_priv.limits[RAPL_DOMAIN_PACKAGE] = 3;
rapl_msr_priv.regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_PL4] =
MSR_VR_CURRENT_CONFIG;
pr_info("PL4 support detected.\n");
}
rapl_msr_priv.control_type = powercap_register_control_type(NULL, "intel-rapl", NULL);
if (IS_ERR(rapl_msr_priv.control_type)) {
pr_debug("failed to register powercap control_type.\n");
return PTR_ERR(rapl_msr_priv.control_type);
}
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powercap/rapl:online",
rapl_cpu_online, rapl_cpu_down_prep);
if (ret < 0)
goto out;
rapl_msr_priv.pcap_rapl_online = ret;
return 0;
out:
if (ret)
powercap_unregister_control_type(rapl_msr_priv.control_type);
return ret;
}
static int rapl_msr_remove(struct platform_device *pdev)
{
cpuhp_remove_state(rapl_msr_priv.pcap_rapl_online);
powercap_unregister_control_type(rapl_msr_priv.control_type);
return 0;
}
static const struct platform_device_id rapl_msr_ids[] = {
{ .name = "intel_rapl_msr", },
{}
};
MODULE_DEVICE_TABLE(platform, rapl_msr_ids);
static struct platform_driver intel_rapl_msr_driver = {
.probe = rapl_msr_probe,
.remove = rapl_msr_remove,
.id_table = rapl_msr_ids,
.driver = {
.name = "intel_rapl_msr",
},
};
module_platform_driver(intel_rapl_msr_driver);
MODULE_DESCRIPTION("Driver for Intel RAPL (Running Average Power Limit) control via MSR interface");
MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
MODULE_LICENSE("GPL v2");