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 #define MSR_VR_CURRENT_CONFIG 0x00000601 32 33 /* private data for RAPL MSR Interface */ 34 static struct rapl_if_priv rapl_msr_priv = { 35 .reg_unit = MSR_RAPL_POWER_UNIT, 36 .regs[RAPL_DOMAIN_PACKAGE] = { 37 MSR_PKG_POWER_LIMIT, MSR_PKG_ENERGY_STATUS, MSR_PKG_PERF_STATUS, 0, MSR_PKG_POWER_INFO }, 38 .regs[RAPL_DOMAIN_PP0] = { 39 MSR_PP0_POWER_LIMIT, MSR_PP0_ENERGY_STATUS, 0, MSR_PP0_POLICY, 0 }, 40 .regs[RAPL_DOMAIN_PP1] = { 41 MSR_PP1_POWER_LIMIT, MSR_PP1_ENERGY_STATUS, 0, MSR_PP1_POLICY, 0 }, 42 .regs[RAPL_DOMAIN_DRAM] = { 43 MSR_DRAM_POWER_LIMIT, MSR_DRAM_ENERGY_STATUS, MSR_DRAM_PERF_STATUS, 0, MSR_DRAM_POWER_INFO }, 44 .regs[RAPL_DOMAIN_PLATFORM] = { 45 MSR_PLATFORM_POWER_LIMIT, MSR_PLATFORM_ENERGY_STATUS, 0, 0, 0}, 46 .limits[RAPL_DOMAIN_PACKAGE] = 2, 47 }; 48 49 /* Handles CPU hotplug on multi-socket systems. 50 * If a CPU goes online as the first CPU of the physical package 51 * we add the RAPL package to the system. Similarly, when the last 52 * CPU of the package is removed, we remove the RAPL package and its 53 * associated domains. Cooling devices are handled accordingly at 54 * per-domain level. 55 */ 56 static int rapl_cpu_online(unsigned int cpu) 57 { 58 struct rapl_package *rp; 59 60 rp = rapl_find_package_domain(cpu, &rapl_msr_priv); 61 if (!rp) { 62 rp = rapl_add_package(cpu, &rapl_msr_priv); 63 if (IS_ERR(rp)) 64 return PTR_ERR(rp); 65 } 66 cpumask_set_cpu(cpu, &rp->cpumask); 67 return 0; 68 } 69 70 static int rapl_cpu_down_prep(unsigned int cpu) 71 { 72 struct rapl_package *rp; 73 int lead_cpu; 74 75 rp = rapl_find_package_domain(cpu, &rapl_msr_priv); 76 if (!rp) 77 return 0; 78 79 cpumask_clear_cpu(cpu, &rp->cpumask); 80 lead_cpu = cpumask_first(&rp->cpumask); 81 if (lead_cpu >= nr_cpu_ids) 82 rapl_remove_package(rp); 83 else if (rp->lead_cpu == cpu) 84 rp->lead_cpu = lead_cpu; 85 return 0; 86 } 87 88 static int rapl_msr_read_raw(int cpu, struct reg_action *ra) 89 { 90 u32 msr = (u32)ra->reg; 91 92 if (rdmsrl_safe_on_cpu(cpu, msr, &ra->value)) { 93 pr_debug("failed to read msr 0x%x on cpu %d\n", msr, cpu); 94 return -EIO; 95 } 96 ra->value &= ra->mask; 97 return 0; 98 } 99 100 static void rapl_msr_update_func(void *info) 101 { 102 struct reg_action *ra = info; 103 u32 msr = (u32)ra->reg; 104 u64 val; 105 106 ra->err = rdmsrl_safe(msr, &val); 107 if (ra->err) 108 return; 109 110 val &= ~ra->mask; 111 val |= ra->value; 112 113 ra->err = wrmsrl_safe(msr, val); 114 } 115 116 static int rapl_msr_write_raw(int cpu, struct reg_action *ra) 117 { 118 int ret; 119 120 ret = smp_call_function_single(cpu, rapl_msr_update_func, ra, 1); 121 if (WARN_ON_ONCE(ret)) 122 return ret; 123 124 return ra->err; 125 } 126 127 /* List of verified CPUs. */ 128 static const struct x86_cpu_id pl4_support_ids[] = { 129 { X86_VENDOR_INTEL, 6, INTEL_FAM6_TIGERLAKE_L, X86_FEATURE_ANY }, 130 {} 131 }; 132 133 static int rapl_msr_probe(struct platform_device *pdev) 134 { 135 const struct x86_cpu_id *id = x86_match_cpu(pl4_support_ids); 136 int ret; 137 138 rapl_msr_priv.read_raw = rapl_msr_read_raw; 139 rapl_msr_priv.write_raw = rapl_msr_write_raw; 140 141 if (id) { 142 rapl_msr_priv.limits[RAPL_DOMAIN_PACKAGE] = 3; 143 rapl_msr_priv.regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_PL4] = 144 MSR_VR_CURRENT_CONFIG; 145 pr_info("PL4 support detected.\n"); 146 } 147 148 rapl_msr_priv.control_type = powercap_register_control_type(NULL, "intel-rapl", NULL); 149 if (IS_ERR(rapl_msr_priv.control_type)) { 150 pr_debug("failed to register powercap control_type.\n"); 151 return PTR_ERR(rapl_msr_priv.control_type); 152 } 153 154 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powercap/rapl:online", 155 rapl_cpu_online, rapl_cpu_down_prep); 156 if (ret < 0) 157 goto out; 158 rapl_msr_priv.pcap_rapl_online = ret; 159 160 /* Don't bail out if PSys is not supported */ 161 rapl_add_platform_domain(&rapl_msr_priv); 162 163 return 0; 164 165 out: 166 if (ret) 167 powercap_unregister_control_type(rapl_msr_priv.control_type); 168 return ret; 169 } 170 171 static int rapl_msr_remove(struct platform_device *pdev) 172 { 173 cpuhp_remove_state(rapl_msr_priv.pcap_rapl_online); 174 rapl_remove_platform_domain(&rapl_msr_priv); 175 powercap_unregister_control_type(rapl_msr_priv.control_type); 176 return 0; 177 } 178 179 static const struct platform_device_id rapl_msr_ids[] = { 180 { .name = "intel_rapl_msr", }, 181 {} 182 }; 183 MODULE_DEVICE_TABLE(platform, rapl_msr_ids); 184 185 static struct platform_driver intel_rapl_msr_driver = { 186 .probe = rapl_msr_probe, 187 .remove = rapl_msr_remove, 188 .id_table = rapl_msr_ids, 189 .driver = { 190 .name = "intel_rapl_msr", 191 }, 192 }; 193 194 module_platform_driver(intel_rapl_msr_driver); 195 196 MODULE_DESCRIPTION("Driver for Intel RAPL (Running Average Power Limit) control via MSR interface"); 197 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>"); 198 MODULE_LICENSE("GPL v2"); 199