1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Intel Running Average Power Limit (RAPL) Driver via MSR interface 4 * Copyright (c) 2019, Intel Corporation. 5 */ 6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 7 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/list.h> 11 #include <linux/types.h> 12 #include <linux/device.h> 13 #include <linux/slab.h> 14 #include <linux/log2.h> 15 #include <linux/bitmap.h> 16 #include <linux/delay.h> 17 #include <linux/sysfs.h> 18 #include <linux/cpu.h> 19 #include <linux/powercap.h> 20 #include <linux/suspend.h> 21 #include <linux/intel_rapl.h> 22 #include <linux/processor.h> 23 #include <linux/platform_device.h> 24 25 #include <asm/iosf_mbi.h> 26 #include <asm/cpu_device_id.h> 27 #include <asm/intel-family.h> 28 29 /* Local defines */ 30 #define MSR_PLATFORM_POWER_LIMIT 0x0000065C 31 32 /* private data for RAPL MSR Interface */ 33 static struct rapl_if_priv rapl_msr_priv = { 34 .reg_unit = MSR_RAPL_POWER_UNIT, 35 .regs[RAPL_DOMAIN_PACKAGE] = { 36 MSR_PKG_POWER_LIMIT, MSR_PKG_ENERGY_STATUS, MSR_PKG_PERF_STATUS, 0, MSR_PKG_POWER_INFO }, 37 .regs[RAPL_DOMAIN_PP0] = { 38 MSR_PP0_POWER_LIMIT, MSR_PP0_ENERGY_STATUS, 0, MSR_PP0_POLICY, 0 }, 39 .regs[RAPL_DOMAIN_PP1] = { 40 MSR_PP1_POWER_LIMIT, MSR_PP1_ENERGY_STATUS, 0, MSR_PP1_POLICY, 0 }, 41 .regs[RAPL_DOMAIN_DRAM] = { 42 MSR_DRAM_POWER_LIMIT, MSR_DRAM_ENERGY_STATUS, MSR_DRAM_PERF_STATUS, 0, MSR_DRAM_POWER_INFO }, 43 .regs[RAPL_DOMAIN_PLATFORM] = { 44 MSR_PLATFORM_POWER_LIMIT, MSR_PLATFORM_ENERGY_STATUS, 0, 0, 0}, 45 .limits[RAPL_DOMAIN_PACKAGE] = 2, 46 }; 47 48 /* Handles CPU hotplug on multi-socket systems. 49 * If a CPU goes online as the first CPU of the physical package 50 * we add the RAPL package to the system. Similarly, when the last 51 * CPU of the package is removed, we remove the RAPL package and its 52 * associated domains. Cooling devices are handled accordingly at 53 * per-domain level. 54 */ 55 static int rapl_cpu_online(unsigned int cpu) 56 { 57 struct rapl_package *rp; 58 59 rp = rapl_find_package_domain(cpu, &rapl_msr_priv); 60 if (!rp) { 61 rp = rapl_add_package(cpu, &rapl_msr_priv); 62 if (IS_ERR(rp)) 63 return PTR_ERR(rp); 64 } 65 cpumask_set_cpu(cpu, &rp->cpumask); 66 return 0; 67 } 68 69 static int rapl_cpu_down_prep(unsigned int cpu) 70 { 71 struct rapl_package *rp; 72 int lead_cpu; 73 74 rp = rapl_find_package_domain(cpu, &rapl_msr_priv); 75 if (!rp) 76 return 0; 77 78 cpumask_clear_cpu(cpu, &rp->cpumask); 79 lead_cpu = cpumask_first(&rp->cpumask); 80 if (lead_cpu >= nr_cpu_ids) 81 rapl_remove_package(rp); 82 else if (rp->lead_cpu == cpu) 83 rp->lead_cpu = lead_cpu; 84 return 0; 85 } 86 87 static int rapl_msr_read_raw(int cpu, struct reg_action *ra) 88 { 89 u32 msr = (u32)ra->reg; 90 91 if (rdmsrl_safe_on_cpu(cpu, msr, &ra->value)) { 92 pr_debug("failed to read msr 0x%x on cpu %d\n", msr, cpu); 93 return -EIO; 94 } 95 ra->value &= ra->mask; 96 return 0; 97 } 98 99 static void rapl_msr_update_func(void *info) 100 { 101 struct reg_action *ra = info; 102 u32 msr = (u32)ra->reg; 103 u64 val; 104 105 ra->err = rdmsrl_safe(msr, &val); 106 if (ra->err) 107 return; 108 109 val &= ~ra->mask; 110 val |= ra->value; 111 112 ra->err = wrmsrl_safe(msr, val); 113 } 114 115 static int rapl_msr_write_raw(int cpu, struct reg_action *ra) 116 { 117 int ret; 118 119 ret = smp_call_function_single(cpu, rapl_msr_update_func, ra, 1); 120 if (WARN_ON_ONCE(ret)) 121 return ret; 122 123 return ra->err; 124 } 125 126 static int rapl_msr_probe(struct platform_device *pdev) 127 { 128 int ret; 129 130 rapl_msr_priv.read_raw = rapl_msr_read_raw; 131 rapl_msr_priv.write_raw = rapl_msr_write_raw; 132 133 rapl_msr_priv.control_type = powercap_register_control_type(NULL, "intel-rapl", NULL); 134 if (IS_ERR(rapl_msr_priv.control_type)) { 135 pr_debug("failed to register powercap control_type.\n"); 136 return PTR_ERR(rapl_msr_priv.control_type); 137 } 138 139 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powercap/rapl:online", 140 rapl_cpu_online, rapl_cpu_down_prep); 141 if (ret < 0) 142 goto out; 143 rapl_msr_priv.pcap_rapl_online = ret; 144 145 /* Don't bail out if PSys is not supported */ 146 rapl_add_platform_domain(&rapl_msr_priv); 147 148 return 0; 149 150 out: 151 if (ret) 152 powercap_unregister_control_type(rapl_msr_priv.control_type); 153 return ret; 154 } 155 156 static int rapl_msr_remove(struct platform_device *pdev) 157 { 158 cpuhp_remove_state(rapl_msr_priv.pcap_rapl_online); 159 rapl_remove_platform_domain(&rapl_msr_priv); 160 powercap_unregister_control_type(rapl_msr_priv.control_type); 161 return 0; 162 } 163 164 static const struct platform_device_id rapl_msr_ids[] = { 165 { .name = "intel_rapl_msr", }, 166 {} 167 }; 168 MODULE_DEVICE_TABLE(platform, rapl_msr_ids); 169 170 static struct platform_driver intel_rapl_msr_driver = { 171 .probe = rapl_msr_probe, 172 .remove = rapl_msr_remove, 173 .id_table = rapl_msr_ids, 174 .driver = { 175 .name = "intel_rapl_msr", 176 }, 177 }; 178 179 module_platform_driver(intel_rapl_msr_driver); 180 181 MODULE_DESCRIPTION("Driver for Intel RAPL (Running Average Power Limit) control via MSR interface"); 182 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); 183 MODULE_LICENSE("GPL v2"); 184