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
36 static struct rapl_if_priv rapl_msr_priv_intel = {
37 .reg_unit = MSR_RAPL_POWER_UNIT,
38 .regs[RAPL_DOMAIN_PACKAGE] = {
39 MSR_PKG_POWER_LIMIT, MSR_PKG_ENERGY_STATUS, MSR_PKG_PERF_STATUS, 0, MSR_PKG_POWER_INFO },
40 .regs[RAPL_DOMAIN_PP0] = {
41 MSR_PP0_POWER_LIMIT, MSR_PP0_ENERGY_STATUS, 0, MSR_PP0_POLICY, 0 },
42 .regs[RAPL_DOMAIN_PP1] = {
43 MSR_PP1_POWER_LIMIT, MSR_PP1_ENERGY_STATUS, 0, MSR_PP1_POLICY, 0 },
44 .regs[RAPL_DOMAIN_DRAM] = {
45 MSR_DRAM_POWER_LIMIT, MSR_DRAM_ENERGY_STATUS, MSR_DRAM_PERF_STATUS, 0, MSR_DRAM_POWER_INFO },
46 .regs[RAPL_DOMAIN_PLATFORM] = {
47 MSR_PLATFORM_POWER_LIMIT, MSR_PLATFORM_ENERGY_STATUS, 0, 0, 0},
48 .limits[RAPL_DOMAIN_PACKAGE] = 2,
49 .limits[RAPL_DOMAIN_PLATFORM] = 2,
50 };
51
52 static struct rapl_if_priv rapl_msr_priv_amd = {
53 .reg_unit = MSR_AMD_RAPL_POWER_UNIT,
54 .regs[RAPL_DOMAIN_PACKAGE] = {
55 0, MSR_AMD_PKG_ENERGY_STATUS, 0, 0, 0 },
56 .regs[RAPL_DOMAIN_PP0] = {
57 0, MSR_AMD_CORE_ENERGY_STATUS, 0, 0, 0 },
58 };
59
60 /* Handles CPU hotplug on multi-socket systems.
61 * If a CPU goes online as the first CPU of the physical package
62 * we add the RAPL package to the system. Similarly, when the last
63 * CPU of the package is removed, we remove the RAPL package and its
64 * associated domains. Cooling devices are handled accordingly at
65 * per-domain level.
66 */
rapl_cpu_online(unsigned int cpu)67 static int rapl_cpu_online(unsigned int cpu)
68 {
69 struct rapl_package *rp;
70
71 rp = rapl_find_package_domain(cpu, rapl_msr_priv);
72 if (!rp) {
73 rp = rapl_add_package(cpu, rapl_msr_priv);
74 if (IS_ERR(rp))
75 return PTR_ERR(rp);
76 }
77 cpumask_set_cpu(cpu, &rp->cpumask);
78 return 0;
79 }
80
rapl_cpu_down_prep(unsigned int cpu)81 static int rapl_cpu_down_prep(unsigned int cpu)
82 {
83 struct rapl_package *rp;
84 int lead_cpu;
85
86 rp = rapl_find_package_domain(cpu, rapl_msr_priv);
87 if (!rp)
88 return 0;
89
90 cpumask_clear_cpu(cpu, &rp->cpumask);
91 lead_cpu = cpumask_first(&rp->cpumask);
92 if (lead_cpu >= nr_cpu_ids)
93 rapl_remove_package(rp);
94 else if (rp->lead_cpu == cpu)
95 rp->lead_cpu = lead_cpu;
96 return 0;
97 }
98
rapl_msr_read_raw(int cpu,struct reg_action * ra)99 static int rapl_msr_read_raw(int cpu, struct reg_action *ra)
100 {
101 u32 msr = (u32)ra->reg;
102
103 if (rdmsrl_safe_on_cpu(cpu, msr, &ra->value)) {
104 pr_debug("failed to read msr 0x%x on cpu %d\n", msr, cpu);
105 return -EIO;
106 }
107 ra->value &= ra->mask;
108 return 0;
109 }
110
rapl_msr_update_func(void * info)111 static void rapl_msr_update_func(void *info)
112 {
113 struct reg_action *ra = info;
114 u32 msr = (u32)ra->reg;
115 u64 val;
116
117 ra->err = rdmsrl_safe(msr, &val);
118 if (ra->err)
119 return;
120
121 val &= ~ra->mask;
122 val |= ra->value;
123
124 ra->err = wrmsrl_safe(msr, val);
125 }
126
rapl_msr_write_raw(int cpu,struct reg_action * ra)127 static int rapl_msr_write_raw(int cpu, struct reg_action *ra)
128 {
129 int ret;
130
131 ret = smp_call_function_single(cpu, rapl_msr_update_func, ra, 1);
132 if (WARN_ON_ONCE(ret))
133 return ret;
134
135 return ra->err;
136 }
137
138 /* List of verified CPUs. */
139 static const struct x86_cpu_id pl4_support_ids[] = {
140 { X86_VENDOR_INTEL, 6, INTEL_FAM6_TIGERLAKE_L, X86_FEATURE_ANY },
141 {}
142 };
143
rapl_msr_probe(struct platform_device * pdev)144 static int rapl_msr_probe(struct platform_device *pdev)
145 {
146 const struct x86_cpu_id *id = x86_match_cpu(pl4_support_ids);
147 int ret;
148
149 switch (boot_cpu_data.x86_vendor) {
150 case X86_VENDOR_INTEL:
151 rapl_msr_priv = &rapl_msr_priv_intel;
152 break;
153 case X86_VENDOR_HYGON:
154 case X86_VENDOR_AMD:
155 rapl_msr_priv = &rapl_msr_priv_amd;
156 break;
157 default:
158 pr_err("intel-rapl does not support CPU vendor %d\n", boot_cpu_data.x86_vendor);
159 return -ENODEV;
160 }
161 rapl_msr_priv->read_raw = rapl_msr_read_raw;
162 rapl_msr_priv->write_raw = rapl_msr_write_raw;
163
164 if (id) {
165 rapl_msr_priv->limits[RAPL_DOMAIN_PACKAGE] = 3;
166 rapl_msr_priv->regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_PL4] =
167 MSR_VR_CURRENT_CONFIG;
168 pr_info("PL4 support detected.\n");
169 }
170
171 rapl_msr_priv->control_type = powercap_register_control_type(NULL, "intel-rapl", NULL);
172 if (IS_ERR(rapl_msr_priv->control_type)) {
173 pr_debug("failed to register powercap control_type.\n");
174 return PTR_ERR(rapl_msr_priv->control_type);
175 }
176
177 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powercap/rapl:online",
178 rapl_cpu_online, rapl_cpu_down_prep);
179 if (ret < 0)
180 goto out;
181 rapl_msr_priv->pcap_rapl_online = ret;
182
183 return 0;
184
185 out:
186 if (ret)
187 powercap_unregister_control_type(rapl_msr_priv->control_type);
188 return ret;
189 }
190
rapl_msr_remove(struct platform_device * pdev)191 static int rapl_msr_remove(struct platform_device *pdev)
192 {
193 cpuhp_remove_state(rapl_msr_priv->pcap_rapl_online);
194 powercap_unregister_control_type(rapl_msr_priv->control_type);
195 return 0;
196 }
197
198 static const struct platform_device_id rapl_msr_ids[] = {
199 { .name = "intel_rapl_msr", },
200 {}
201 };
202 MODULE_DEVICE_TABLE(platform, rapl_msr_ids);
203
204 static struct platform_driver intel_rapl_msr_driver = {
205 .probe = rapl_msr_probe,
206 .remove = rapl_msr_remove,
207 .id_table = rapl_msr_ids,
208 .driver = {
209 .name = "intel_rapl_msr",
210 },
211 };
212
213 module_platform_driver(intel_rapl_msr_driver);
214
215 MODULE_DESCRIPTION("Driver for Intel RAPL (Running Average Power Limit) control via MSR interface");
216 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
217 MODULE_LICENSE("GPL v2");
218