summaryrefslogtreecommitdiffstats
path: root/arch/x86/lib/msr.c
blob: caa24aca8115707be495a026fe89f20baea5164a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
#include <linux/module.h>
#include <linux/preempt.h>
#include <linux/smp.h>
#include <asm/msr.h>

struct msr_info {
	u32 msr_no;
	struct msr reg;
	struct msr *msrs;
	int off;
	int err;
};

static void __rdmsr_on_cpu(void *info)
{
	struct msr_info *rv = info;
	struct msr *reg;
	int this_cpu = raw_smp_processor_id();

	if (rv->msrs)
		reg = &rv->msrs[this_cpu - rv->off];
	else
		reg = &rv->reg;

	rdmsr(rv->msr_no, reg->l, reg->h);
}

static void __wrmsr_on_cpu(void *info)
{
	struct msr_info *rv = info;
	struct msr *reg;
	int this_cpu = raw_smp_processor_id();

	if (rv->msrs)
		reg = &rv->msrs[this_cpu - rv->off];
	else
		reg = &rv->reg;

	wrmsr(rv->msr_no, reg->l, reg->h);
}

int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
	int err;
	struct msr_info rv;

	memset(&rv, 0, sizeof(rv));

	rv.msr_no = msr_no;
	err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
	*l = rv.reg.l;
	*h = rv.reg.h;

	return err;
}
EXPORT_SYMBOL(rdmsr_on_cpu);

int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
	int err;
	struct msr_info rv;

	memset(&rv, 0, sizeof(rv));

	rv.msr_no = msr_no;
	rv.reg.l = l;
	rv.reg.h = h;
	err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);

	return err;
}
EXPORT_SYMBOL(wrmsr_on_cpu);

/* rdmsr on a bunch of CPUs
 *
 * @mask:       which CPUs
 * @msr_no:     which MSR
 * @msrs:       array of MSR values
 *
 */
void rdmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs)
{
	struct msr_info rv;
	int this_cpu;

	memset(&rv, 0, sizeof(rv));

	rv.off    = cpumask_first(mask);
	rv.msrs	  = msrs;
	rv.msr_no = msr_no;

	this_cpu = get_cpu();

	if (cpumask_test_cpu(this_cpu, mask))
		__rdmsr_on_cpu(&rv);

	smp_call_function_many(mask, __rdmsr_on_cpu, &rv, 1);
	put_cpu();
}
EXPORT_SYMBOL(rdmsr_on_cpus);

/*
 * wrmsr on a bunch of CPUs
 *
 * @mask:       which CPUs
 * @msr_no:     which MSR
 * @msrs:       array of MSR values
 *
 */
void wrmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs)
{
	struct msr_info rv;
	int this_cpu;

	memset(&rv, 0, sizeof(rv));

	rv.off    = cpumask_first(mask);
	rv.msrs   = msrs;
	rv.msr_no = msr_no;

	this_cpu = get_cpu();

	if (cpumask_test_cpu(this_cpu, mask))
		__wrmsr_on_cpu(&rv);

	smp_call_function_many(mask, __wrmsr_on_cpu, &rv, 1);
	put_cpu();
}
EXPORT_SYMBOL(wrmsr_on_cpus);

/* These "safe" variants are slower and should be used when the target MSR
   may not actually exist. */
static void __rdmsr_safe_on_cpu(void *info)
{
	struct msr_info *rv = info;

	rv->err = rdmsr_safe(rv->msr_no, &rv->reg.l, &rv->reg.h);
}

static void __wrmsr_safe_on_cpu(void *info)
{
	struct msr_info *rv = info;

	rv->err = wrmsr_safe(rv->msr_no, rv->reg.l, rv->reg.h);
}

int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
	int err;
	struct msr_info rv;

	memset(&rv, 0, sizeof(rv));

	rv.msr_no = msr_no;
	err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu, &rv, 1);
	*l = rv.reg.l;
	*h = rv.reg.h;

	return err ? err : rv.err;
}
EXPORT_SYMBOL(rdmsr_safe_on_cpu);

int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
	int err;
	struct msr_info rv;

	memset(&rv, 0, sizeof(rv));

	rv.msr_no = msr_no;
	rv.reg.l = l;
	rv.reg.h = h;
	err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);

	return err ? err : rv.err;
}
EXPORT_SYMBOL(wrmsr_safe_on_cpu);