aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/lib/msr-smp.c
blob: fee8b9c0520c9954e3cf9093332e1a9b53009b8b (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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
// SPDX-License-Identifier: GPL-2.0
#include <linux/export.h>
#include <linux/preempt.h>
#include <linux/smp.h>
#include <linux/completion.h>
#include <asm/msr.h>

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 = per_cpu_ptr(rv->msrs, this_cpu);
	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 = per_cpu_ptr(rv->msrs, this_cpu);
	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 rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
{
	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);
	*q = rv.reg.q;

	return err;
}
EXPORT_SYMBOL(rdmsrl_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);

int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
{
	int err;
	struct msr_info rv;

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

	rv.msr_no = msr_no;
	rv.reg.q = q;

	err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);

	return err;
}
EXPORT_SYMBOL(wrmsrl_on_cpu);

static void __rwmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
			    struct msr *msrs,
			    void (*msr_func) (void *info))
{
	struct msr_info rv;
	int this_cpu;

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

	rv.msrs	  = msrs;
	rv.msr_no = msr_no;

	this_cpu = get_cpu();

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

	smp_call_function_many(mask, msr_func, &rv, 1);
	put_cpu();
}

/* rdmsr on a bunch of CPUs
 *
 * @mask:       which CPUs
 * @msr_no:     which MSR
 * @msrs:       array of MSR values
 *
 */
void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
{
	__rwmsr_on_cpus(mask, msr_no, msrs, __rdmsr_on_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 struct cpumask *mask, u32 msr_no, struct msr *msrs)
{
	__rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu);
}
EXPORT_SYMBOL(wrmsr_on_cpus);

struct msr_info_completion {
	struct msr_info		msr;
	struct completion	done;
};

/* 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_completion *rv = info;

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

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)
{
	struct msr_info_completion rv;
	call_single_data_t csd = {
		.func	= __rdmsr_safe_on_cpu,
		.info	= &rv,
	};
	int err;

	memset(&rv, 0, sizeof(rv));
	init_completion(&rv.done);
	rv.msr.msr_no = msr_no;

	err = smp_call_function_single_async(cpu, &csd);
	if (!err) {
		wait_for_completion(&rv.done);
		err = rv.msr.err;
	}
	*l = rv.msr.reg.l;
	*h = rv.msr.reg.h;

	return 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);

int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
{
	int err;
	struct msr_info rv;

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

	rv.msr_no = msr_no;
	rv.reg.q = q;

	err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);

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

int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
{
	u32 low, high;
	int err;

	err = rdmsr_safe_on_cpu(cpu, msr_no, &low, &high);
	*q = (u64)high << 32 | low;

	return err;
}
EXPORT_SYMBOL(rdmsrl_safe_on_cpu);

/*
 * These variants are significantly slower, but allows control over
 * the entire 32-bit GPR set.
 */
static void __rdmsr_safe_regs_on_cpu(void *info)
{
	struct msr_regs_info *rv = info;

	rv->err = rdmsr_safe_regs(rv->regs);
}

static void __wrmsr_safe_regs_on_cpu(void *info)
{
	struct msr_regs_info *rv = info;

	rv->err = wrmsr_safe_regs(rv->regs);
}

int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
{
	int err;
	struct msr_regs_info rv;

	rv.regs   = regs;
	rv.err    = -EIO;
	err = smp_call_function_single(cpu, __rdmsr_safe_regs_on_cpu, &rv, 1);

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

int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
{
	int err;
	struct msr_regs_info rv;

	rv.regs = regs;
	rv.err  = -EIO;
	err = smp_call_function_single(cpu, __wrmsr_safe_regs_on_cpu, &rv, 1);

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