xref: /linux/tools/power/cpupower/utils/idle_monitor/snb_idle.c (revision b4db9f840283caca0d904436f187ef56a9126eaa)
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_C2_RESIDENCY	0x60D
19 #define MSR_PKG_C7_RESIDENCY	0x3FA
20 #define MSR_CORE_C7_RESIDENCY	0x3FE
21 
22 #define MSR_TSC	0x10
23 
24 enum intel_snb_id { C7 = 0, PC2, PC7, SNB_CSTATE_COUNT, TSC = 0xFFFF };
25 
26 static int snb_get_count_percent(unsigned int self_id, double *percent,
27 				 unsigned int cpu);
28 
29 static cstate_t snb_cstates[SNB_CSTATE_COUNT] = {
30 	{
31 		.name			= "C7",
32 		.desc			= N_("Processor Core C7"),
33 		.id			= C7,
34 		.range			= RANGE_CORE,
35 		.get_count_percent	= snb_get_count_percent,
36 	},
37 	{
38 		.name			= "PC2",
39 		.desc			= N_("Processor Package C2"),
40 		.id			= PC2,
41 		.range			= RANGE_PACKAGE,
42 		.get_count_percent	= snb_get_count_percent,
43 	},
44 	{
45 		.name			= "PC7",
46 		.desc			= N_("Processor Package C7"),
47 		.id			= PC7,
48 		.range			= RANGE_PACKAGE,
49 		.get_count_percent	= snb_get_count_percent,
50 	},
51 };
52 
53 static unsigned long long tsc_at_measure_start;
54 static unsigned long long tsc_at_measure_end;
55 static unsigned long long *previous_count[SNB_CSTATE_COUNT];
56 static unsigned long long *current_count[SNB_CSTATE_COUNT];
57 /* valid flag for all CPUs. If a MSR read failed it will be zero */
58 static int *is_valid;
59 
60 static int snb_get_count(enum intel_snb_id id, unsigned long long *val,
61 			unsigned int cpu)
62 {
63 	int msr;
64 
65 	switch (id) {
66 	case C7:
67 		msr = MSR_CORE_C7_RESIDENCY;
68 		break;
69 	case PC2:
70 		msr = MSR_PKG_C2_RESIDENCY;
71 		break;
72 	case PC7:
73 		msr = MSR_PKG_C7_RESIDENCY;
74 		break;
75 	case TSC:
76 		msr = MSR_TSC;
77 		break;
78 	default:
79 		return -1;
80 	}
81 	if (read_msr(cpu, msr, val))
82 		return -1;
83 	return 0;
84 }
85 
86 static int snb_get_count_percent(unsigned int id, double *percent,
87 				 unsigned int cpu)
88 {
89 	*percent = 0.0;
90 
91 	if (!is_valid[cpu])
92 		return -1;
93 
94 	*percent = (100.0 *
95 		(current_count[id][cpu] - previous_count[id][cpu])) /
96 		(tsc_at_measure_end - tsc_at_measure_start);
97 
98 	dprint("%s: previous: %llu - current: %llu - (%u)\n",
99 		snb_cstates[id].name, previous_count[id][cpu],
100 		current_count[id][cpu], cpu);
101 
102 	dprint("%s: tsc_diff: %llu - count_diff: %llu - percent: %2.f (%u)\n",
103 	       snb_cstates[id].name,
104 	       (unsigned long long) tsc_at_measure_end - tsc_at_measure_start,
105 	       current_count[id][cpu] - previous_count[id][cpu],
106 	       *percent, cpu);
107 
108 	return 0;
109 }
110 
111 static int snb_start(void)
112 {
113 	int num, cpu;
114 	unsigned long long val;
115 
116 	for (num = 0; num < SNB_CSTATE_COUNT; num++) {
117 		for (cpu = 0; cpu < cpu_count; cpu++) {
118 			snb_get_count(num, &val, cpu);
119 			previous_count[num][cpu] = val;
120 		}
121 	}
122 	snb_get_count(TSC, &tsc_at_measure_start, base_cpu);
123 	return 0;
124 }
125 
126 static int snb_stop(void)
127 {
128 	unsigned long long val;
129 	int num, cpu;
130 
131 	snb_get_count(TSC, &tsc_at_measure_end, base_cpu);
132 
133 	for (num = 0; num < SNB_CSTATE_COUNT; num++) {
134 		for (cpu = 0; cpu < cpu_count; cpu++) {
135 			is_valid[cpu] = !snb_get_count(num, &val, cpu);
136 			current_count[num][cpu] = val;
137 		}
138 	}
139 	return 0;
140 }
141 
142 struct cpuidle_monitor intel_snb_monitor;
143 
144 static struct cpuidle_monitor *snb_register(void)
145 {
146 	int num;
147 
148 	if (cpupower_cpu_info.vendor != X86_VENDOR_INTEL
149 	    || cpupower_cpu_info.family != 6)
150 		return NULL;
151 
152 	switch (cpupower_cpu_info.model) {
153 	case 0x2A: /* SNB */
154 	case 0x2D: /* SNB Xeon */
155 	case 0x3A: /* IVB */
156 	case 0x3E: /* IVB Xeon */
157 	case 0x3C: /* HSW */
158 	case 0x3F: /* HSW */
159 	case 0x45: /* HSW */
160 	case 0x46: /* HSW */
161 		break;
162 	default:
163 		return NULL;
164 	}
165 
166 	is_valid = calloc(cpu_count, sizeof(int));
167 	for (num = 0; num < SNB_CSTATE_COUNT; num++) {
168 		previous_count[num] = calloc(cpu_count,
169 					sizeof(unsigned long long));
170 		current_count[num]  = calloc(cpu_count,
171 					sizeof(unsigned long long));
172 	}
173 	intel_snb_monitor.name_len = strlen(intel_snb_monitor.name);
174 	return &intel_snb_monitor;
175 }
176 
177 void snb_unregister(void)
178 {
179 	int num;
180 	free(is_valid);
181 	for (num = 0; num < SNB_CSTATE_COUNT; num++) {
182 		free(previous_count[num]);
183 		free(current_count[num]);
184 	}
185 }
186 
187 struct cpuidle_monitor intel_snb_monitor = {
188 	.name			= "SandyBridge",
189 	.hw_states		= snb_cstates,
190 	.hw_states_num		= SNB_CSTATE_COUNT,
191 	.start			= snb_start,
192 	.stop			= snb_stop,
193 	.do_register		= snb_register,
194 	.unregister		= snb_unregister,
195 	.flags.needs_root	= 1,
196 	.overflow_s		= 922000000 /* 922337203 seconds TSC overflow
197 					       at 20GHz */
198 };
199 #endif /* defined(__i386__) || defined(__x86_64__) */
200