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  */
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 
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 
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 
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 
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 
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_AMD:
154 		rapl_msr_priv = &rapl_msr_priv_amd;
155 		break;
156 	default:
157 		pr_err("intel-rapl does not support CPU vendor %d\n", boot_cpu_data.x86_vendor);
158 		return -ENODEV;
159 	}
160 	rapl_msr_priv->read_raw = rapl_msr_read_raw;
161 	rapl_msr_priv->write_raw = rapl_msr_write_raw;
162 
163 	if (id) {
164 		rapl_msr_priv->limits[RAPL_DOMAIN_PACKAGE] = 3;
165 		rapl_msr_priv->regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_PL4] =
166 			MSR_VR_CURRENT_CONFIG;
167 		pr_info("PL4 support detected.\n");
168 	}
169 
170 	rapl_msr_priv->control_type = powercap_register_control_type(NULL, "intel-rapl", NULL);
171 	if (IS_ERR(rapl_msr_priv->control_type)) {
172 		pr_debug("failed to register powercap control_type.\n");
173 		return PTR_ERR(rapl_msr_priv->control_type);
174 	}
175 
176 	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powercap/rapl:online",
177 				rapl_cpu_online, rapl_cpu_down_prep);
178 	if (ret < 0)
179 		goto out;
180 	rapl_msr_priv->pcap_rapl_online = ret;
181 
182 	return 0;
183 
184 out:
185 	if (ret)
186 		powercap_unregister_control_type(rapl_msr_priv->control_type);
187 	return ret;
188 }
189 
190 static int rapl_msr_remove(struct platform_device *pdev)
191 {
192 	cpuhp_remove_state(rapl_msr_priv->pcap_rapl_online);
193 	powercap_unregister_control_type(rapl_msr_priv->control_type);
194 	return 0;
195 }
196 
197 static const struct platform_device_id rapl_msr_ids[] = {
198 	{ .name = "intel_rapl_msr", },
199 	{}
200 };
201 MODULE_DEVICE_TABLE(platform, rapl_msr_ids);
202 
203 static struct platform_driver intel_rapl_msr_driver = {
204 	.probe = rapl_msr_probe,
205 	.remove = rapl_msr_remove,
206 	.id_table = rapl_msr_ids,
207 	.driver = {
208 		.name = "intel_rapl_msr",
209 	},
210 };
211 
212 module_platform_driver(intel_rapl_msr_driver);
213 
214 MODULE_DESCRIPTION("Driver for Intel RAPL (Running Average Power Limit) control via MSR interface");
215 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
216 MODULE_LICENSE("GPL v2");
217