xref: /linux/tools/power/cpupower/utils/idle_monitor/nhm_idle.c (revision 4b4193256c8d3bc3a5397b5cd9494c2ad386317d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  (C) 2010,2011       Thomas Renninger <trenn@suse.de>, Novell Inc.
4  *
5  *  Based on Len Brown's <lenb@kernel.org> turbostat tool.
6  */
7 
8 #if defined(__i386__) || defined(__x86_64__)
9 
10 #include <stdio.h>
11 #include <stdint.h>
12 #include <stdlib.h>
13 #include <string.h>
14 
15 #include "helpers/helpers.h"
16 #include "idle_monitor/cpupower-monitor.h"
17 
18 #define MSR_PKG_C3_RESIDENCY	0x3F8
19 #define MSR_PKG_C6_RESIDENCY	0x3F9
20 #define MSR_CORE_C3_RESIDENCY	0x3FC
21 #define MSR_CORE_C6_RESIDENCY	0x3FD
22 
23 #define MSR_TSC	0x10
24 
25 #define NHM_CSTATE_COUNT 4
26 
27 enum intel_nhm_id { C3 = 0, C6, PC3, PC6, TSC = 0xFFFF };
28 
29 static int nhm_get_count_percent(unsigned int self_id, double *percent,
30 				 unsigned int cpu);
31 
32 static cstate_t nhm_cstates[NHM_CSTATE_COUNT] = {
33 	{
34 		.name			= "C3",
35 		.desc			= N_("Processor Core C3"),
36 		.id			= C3,
37 		.range			= RANGE_CORE,
38 		.get_count_percent	= nhm_get_count_percent,
39 	},
40 	{
41 		.name			= "C6",
42 		.desc			= N_("Processor Core C6"),
43 		.id			= C6,
44 		.range			= RANGE_CORE,
45 		.get_count_percent	= nhm_get_count_percent,
46 	},
47 
48 	{
49 		.name			= "PC3",
50 		.desc			= N_("Processor Package C3"),
51 		.id			= PC3,
52 		.range			= RANGE_PACKAGE,
53 		.get_count_percent	= nhm_get_count_percent,
54 	},
55 	{
56 		.name			= "PC6",
57 		.desc			= N_("Processor Package C6"),
58 		.id			= PC6,
59 		.range			= RANGE_PACKAGE,
60 		.get_count_percent	= nhm_get_count_percent,
61 	},
62 };
63 
64 static unsigned long long tsc_at_measure_start;
65 static unsigned long long tsc_at_measure_end;
66 static unsigned long long *previous_count[NHM_CSTATE_COUNT];
67 static unsigned long long *current_count[NHM_CSTATE_COUNT];
68 /* valid flag for all CPUs. If a MSR read failed it will be zero */
69 static int *is_valid;
70 
nhm_get_count(enum intel_nhm_id id,unsigned long long * val,unsigned int cpu)71 static int nhm_get_count(enum intel_nhm_id id, unsigned long long *val,
72 			unsigned int cpu)
73 {
74 	int msr;
75 
76 	switch (id) {
77 	case C3:
78 		msr = MSR_CORE_C3_RESIDENCY;
79 		break;
80 	case C6:
81 		msr = MSR_CORE_C6_RESIDENCY;
82 		break;
83 	case PC3:
84 		msr = MSR_PKG_C3_RESIDENCY;
85 		break;
86 	case PC6:
87 		msr = MSR_PKG_C6_RESIDENCY;
88 		break;
89 	case TSC:
90 		msr = MSR_TSC;
91 		break;
92 	default:
93 		return -1;
94 	}
95 	if (read_msr(cpu, msr, val))
96 		return -1;
97 
98 	return 0;
99 }
100 
nhm_get_count_percent(unsigned int id,double * percent,unsigned int cpu)101 static int nhm_get_count_percent(unsigned int id, double *percent,
102 				 unsigned int cpu)
103 {
104 	*percent = 0.0;
105 
106 	if (!is_valid[cpu])
107 		return -1;
108 
109 	*percent = (100.0 *
110 		(current_count[id][cpu] - previous_count[id][cpu])) /
111 		(tsc_at_measure_end - tsc_at_measure_start);
112 
113 	dprint("%s: previous: %llu - current: %llu - (%u)\n",
114 		nhm_cstates[id].name, previous_count[id][cpu],
115 		current_count[id][cpu], cpu);
116 
117 	dprint("%s: tsc_diff: %llu - count_diff: %llu - percent: %2.f (%u)\n",
118 	       nhm_cstates[id].name,
119 	       (unsigned long long) tsc_at_measure_end - tsc_at_measure_start,
120 	       current_count[id][cpu] - previous_count[id][cpu],
121 	       *percent, cpu);
122 
123 	return 0;
124 }
125 
nhm_start(void)126 static int nhm_start(void)
127 {
128 	int num, cpu;
129 	unsigned long long dbg, val;
130 
131 	nhm_get_count(TSC, &tsc_at_measure_start, base_cpu);
132 
133 	for (num = 0; num < NHM_CSTATE_COUNT; num++) {
134 		for (cpu = 0; cpu < cpu_count; cpu++) {
135 			is_valid[cpu] = !nhm_get_count(num, &val, cpu);
136 			previous_count[num][cpu] = val;
137 		}
138 	}
139 	nhm_get_count(TSC, &dbg, base_cpu);
140 	dprint("TSC diff: %llu\n", dbg - tsc_at_measure_start);
141 	return 0;
142 }
143 
nhm_stop(void)144 static int nhm_stop(void)
145 {
146 	unsigned long long val;
147 	unsigned long long dbg;
148 	int num, cpu;
149 
150 	nhm_get_count(TSC, &tsc_at_measure_end, base_cpu);
151 
152 	for (num = 0; num < NHM_CSTATE_COUNT; num++) {
153 		for (cpu = 0; cpu < cpu_count; cpu++) {
154 			is_valid[cpu] = !nhm_get_count(num, &val, cpu);
155 			current_count[num][cpu] = val;
156 		}
157 	}
158 	nhm_get_count(TSC, &dbg, base_cpu);
159 	dprint("TSC diff: %llu\n", dbg - tsc_at_measure_end);
160 
161 	return 0;
162 }
163 
164 struct cpuidle_monitor intel_nhm_monitor;
165 
intel_nhm_register(void)166 struct cpuidle_monitor *intel_nhm_register(void)
167 {
168 	int num;
169 
170 	if (cpupower_cpu_info.vendor != X86_VENDOR_INTEL)
171 		return NULL;
172 
173 	if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_INV_TSC))
174 		return NULL;
175 
176 	if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_APERF))
177 		return NULL;
178 
179 	/* Free this at program termination */
180 	is_valid = calloc(cpu_count, sizeof(int));
181 	for (num = 0; num < NHM_CSTATE_COUNT; num++) {
182 		previous_count[num] = calloc(cpu_count,
183 					sizeof(unsigned long long));
184 		current_count[num]  = calloc(cpu_count,
185 					sizeof(unsigned long long));
186 	}
187 
188 	intel_nhm_monitor.name_len = strlen(intel_nhm_monitor.name);
189 	return &intel_nhm_monitor;
190 }
191 
intel_nhm_unregister(void)192 void intel_nhm_unregister(void)
193 {
194 	int num;
195 
196 	for (num = 0; num < NHM_CSTATE_COUNT; num++) {
197 		free(previous_count[num]);
198 		free(current_count[num]);
199 	}
200 	free(is_valid);
201 }
202 
203 struct cpuidle_monitor intel_nhm_monitor = {
204 	.name			= "Nehalem",
205 	.hw_states_num		= NHM_CSTATE_COUNT,
206 	.hw_states		= nhm_cstates,
207 	.start			= nhm_start,
208 	.stop			= nhm_stop,
209 	.do_register		= intel_nhm_register,
210 	.unregister		= intel_nhm_unregister,
211 	.flags.needs_root	= 1,
212 	.overflow_s		= 922000000 /* 922337203 seconds TSC overflow
213 					       at 20GHz */
214 };
215 #endif
216