diff options
Diffstat (limited to 'drivers/powercap/intel_rapl_msr.c')
| -rw-r--r-- | drivers/powercap/intel_rapl_msr.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/powercap/intel_rapl_msr.c b/drivers/powercap/intel_rapl_msr.c new file mode 100644 index 000000000000..89645222e3e0 --- /dev/null +++ b/drivers/powercap/intel_rapl_msr.c @@ -0,0 +1,163 @@ +// 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 <asm/iosf_mbi.h> +#include <asm/cpu_device_id.h> +#include <asm/intel-family.h> + +/* Local defines */ +#define MSR_PLATFORM_POWER_LIMIT 0x0000065C + +/* 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}, +}; + +/* 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) +{ + if (rdmsrl_safe_on_cpu(cpu, ra->reg, &ra->value)) { + pr_debug("failed to read msr 0x%x on cpu %d\n", ra->reg, cpu); + return -EIO; + } + ra->value &= ra->mask; + return 0; +} + +static void rapl_msr_update_func(void *info) +{ + struct reg_action *ra = info; + u64 val; + + ra->err = rdmsrl_safe(ra->reg, &val); + if (ra->err) + return; + + val &= ~ra->mask; + val |= ra->value; + + ra->err = wrmsrl_safe(ra->reg, 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; +} + +static int __init rapl_msr_init(void) +{ + int ret; + + rapl_msr_priv.read_raw = rapl_msr_read_raw; + rapl_msr_priv.write_raw = rapl_msr_write_raw; + + 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; + + /* Don't bail out if PSys is not supported */ + rapl_add_platform_domain(&rapl_msr_priv); + + return 0; + +out: + if (ret) + powercap_unregister_control_type(rapl_msr_priv.control_type); + return ret; +} + +static void __exit rapl_msr_exit(void) +{ + cpuhp_remove_state(rapl_msr_priv.pcap_rapl_online); + rapl_remove_platform_domain(&rapl_msr_priv); + powercap_unregister_control_type(rapl_msr_priv.control_type); +} + +module_init(rapl_msr_init); +module_exit(rapl_msr_exit); + +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"); |