1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/export.h>
3 #include <linux/preempt.h>
4 #include <linux/smp.h>
5 #include <linux/completion.h>
6 #include <asm/msr.h>
7
__rdmsr_on_cpu(void * info)8 static void __rdmsr_on_cpu(void *info)
9 {
10 struct msr_info *rv = info;
11 struct msr *reg;
12 int this_cpu = raw_smp_processor_id();
13
14 if (rv->msrs)
15 reg = per_cpu_ptr(rv->msrs, this_cpu);
16 else
17 reg = &rv->reg;
18
19 rdmsr(rv->msr_no, reg->l, reg->h);
20 }
21
__wrmsr_on_cpu(void * info)22 static void __wrmsr_on_cpu(void *info)
23 {
24 struct msr_info *rv = info;
25 struct msr *reg;
26 int this_cpu = raw_smp_processor_id();
27
28 if (rv->msrs)
29 reg = per_cpu_ptr(rv->msrs, this_cpu);
30 else
31 reg = &rv->reg;
32
33 wrmsr(rv->msr_no, reg->l, reg->h);
34 }
35
rdmsr_on_cpu(unsigned int cpu,u32 msr_no,u32 * l,u32 * h)36 int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
37 {
38 int err;
39 struct msr_info rv;
40
41 memset(&rv, 0, sizeof(rv));
42
43 rv.msr_no = msr_no;
44 err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
45 *l = rv.reg.l;
46 *h = rv.reg.h;
47
48 return err;
49 }
50 EXPORT_SYMBOL(rdmsr_on_cpu);
51
rdmsrl_on_cpu(unsigned int cpu,u32 msr_no,u64 * q)52 int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
53 {
54 int err;
55 struct msr_info rv;
56
57 memset(&rv, 0, sizeof(rv));
58
59 rv.msr_no = msr_no;
60 err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
61 *q = rv.reg.q;
62
63 return err;
64 }
65 EXPORT_SYMBOL(rdmsrl_on_cpu);
66
wrmsr_on_cpu(unsigned int cpu,u32 msr_no,u32 l,u32 h)67 int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
68 {
69 int err;
70 struct msr_info rv;
71
72 memset(&rv, 0, sizeof(rv));
73
74 rv.msr_no = msr_no;
75 rv.reg.l = l;
76 rv.reg.h = h;
77 err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
78
79 return err;
80 }
81 EXPORT_SYMBOL(wrmsr_on_cpu);
82
wrmsrl_on_cpu(unsigned int cpu,u32 msr_no,u64 q)83 int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
84 {
85 int err;
86 struct msr_info rv;
87
88 memset(&rv, 0, sizeof(rv));
89
90 rv.msr_no = msr_no;
91 rv.reg.q = q;
92
93 err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
94
95 return err;
96 }
97 EXPORT_SYMBOL(wrmsrl_on_cpu);
98
__rwmsr_on_cpus(const struct cpumask * mask,u32 msr_no,struct msr * msrs,void (* msr_func)(void * info))99 static void __rwmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
100 struct msr *msrs,
101 void (*msr_func) (void *info))
102 {
103 struct msr_info rv;
104 int this_cpu;
105
106 memset(&rv, 0, sizeof(rv));
107
108 rv.msrs = msrs;
109 rv.msr_no = msr_no;
110
111 this_cpu = get_cpu();
112
113 if (cpumask_test_cpu(this_cpu, mask))
114 msr_func(&rv);
115
116 smp_call_function_many(mask, msr_func, &rv, 1);
117 put_cpu();
118 }
119
120 /* rdmsr on a bunch of CPUs
121 *
122 * @mask: which CPUs
123 * @msr_no: which MSR
124 * @msrs: array of MSR values
125 *
126 */
rdmsr_on_cpus(const struct cpumask * mask,u32 msr_no,struct msr * msrs)127 void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
128 {
129 __rwmsr_on_cpus(mask, msr_no, msrs, __rdmsr_on_cpu);
130 }
131 EXPORT_SYMBOL(rdmsr_on_cpus);
132
133 /*
134 * wrmsr on a bunch of CPUs
135 *
136 * @mask: which CPUs
137 * @msr_no: which MSR
138 * @msrs: array of MSR values
139 *
140 */
wrmsr_on_cpus(const struct cpumask * mask,u32 msr_no,struct msr * msrs)141 void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
142 {
143 __rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu);
144 }
145 EXPORT_SYMBOL(wrmsr_on_cpus);
146
147 struct msr_info_completion {
148 struct msr_info msr;
149 struct completion done;
150 };
151
152 /* These "safe" variants are slower and should be used when the target MSR
153 may not actually exist. */
__rdmsr_safe_on_cpu(void * info)154 static void __rdmsr_safe_on_cpu(void *info)
155 {
156 struct msr_info_completion *rv = info;
157
158 rv->msr.err = rdmsr_safe(rv->msr.msr_no, &rv->msr.reg.l, &rv->msr.reg.h);
159 complete(&rv->done);
160 }
161
__wrmsr_safe_on_cpu(void * info)162 static void __wrmsr_safe_on_cpu(void *info)
163 {
164 struct msr_info *rv = info;
165
166 rv->err = wrmsr_safe(rv->msr_no, rv->reg.l, rv->reg.h);
167 }
168
rdmsr_safe_on_cpu(unsigned int cpu,u32 msr_no,u32 * l,u32 * h)169 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
170 {
171 struct msr_info_completion rv;
172 call_single_data_t csd;
173 int err;
174
175 INIT_CSD(&csd, __rdmsr_safe_on_cpu, &rv);
176
177 memset(&rv, 0, sizeof(rv));
178 init_completion(&rv.done);
179 rv.msr.msr_no = msr_no;
180
181 err = smp_call_function_single_async(cpu, &csd);
182 if (!err) {
183 wait_for_completion(&rv.done);
184 err = rv.msr.err;
185 }
186 *l = rv.msr.reg.l;
187 *h = rv.msr.reg.h;
188
189 return err;
190 }
191 EXPORT_SYMBOL(rdmsr_safe_on_cpu);
192
wrmsr_safe_on_cpu(unsigned int cpu,u32 msr_no,u32 l,u32 h)193 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
194 {
195 int err;
196 struct msr_info rv;
197
198 memset(&rv, 0, sizeof(rv));
199
200 rv.msr_no = msr_no;
201 rv.reg.l = l;
202 rv.reg.h = h;
203 err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
204
205 return err ? err : rv.err;
206 }
207 EXPORT_SYMBOL(wrmsr_safe_on_cpu);
208
wrmsrl_safe_on_cpu(unsigned int cpu,u32 msr_no,u64 q)209 int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
210 {
211 int err;
212 struct msr_info rv;
213
214 memset(&rv, 0, sizeof(rv));
215
216 rv.msr_no = msr_no;
217 rv.reg.q = q;
218
219 err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
220
221 return err ? err : rv.err;
222 }
223 EXPORT_SYMBOL(wrmsrl_safe_on_cpu);
224
rdmsrl_safe_on_cpu(unsigned int cpu,u32 msr_no,u64 * q)225 int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
226 {
227 u32 low, high;
228 int err;
229
230 err = rdmsr_safe_on_cpu(cpu, msr_no, &low, &high);
231 *q = (u64)high << 32 | low;
232
233 return err;
234 }
235 EXPORT_SYMBOL(rdmsrl_safe_on_cpu);
236
237 /*
238 * These variants are significantly slower, but allows control over
239 * the entire 32-bit GPR set.
240 */
__rdmsr_safe_regs_on_cpu(void * info)241 static void __rdmsr_safe_regs_on_cpu(void *info)
242 {
243 struct msr_regs_info *rv = info;
244
245 rv->err = rdmsr_safe_regs(rv->regs);
246 }
247
__wrmsr_safe_regs_on_cpu(void * info)248 static void __wrmsr_safe_regs_on_cpu(void *info)
249 {
250 struct msr_regs_info *rv = info;
251
252 rv->err = wrmsr_safe_regs(rv->regs);
253 }
254
rdmsr_safe_regs_on_cpu(unsigned int cpu,u32 regs[8])255 int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
256 {
257 int err;
258 struct msr_regs_info rv;
259
260 rv.regs = regs;
261 rv.err = -EIO;
262 err = smp_call_function_single(cpu, __rdmsr_safe_regs_on_cpu, &rv, 1);
263
264 return err ? err : rv.err;
265 }
266 EXPORT_SYMBOL(rdmsr_safe_regs_on_cpu);
267
wrmsr_safe_regs_on_cpu(unsigned int cpu,u32 regs[8])268 int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
269 {
270 int err;
271 struct msr_regs_info rv;
272
273 rv.regs = regs;
274 rv.err = -EIO;
275 err = smp_call_function_single(cpu, __wrmsr_safe_regs_on_cpu, &rv, 1);
276
277 return err ? err : rv.err;
278 }
279 EXPORT_SYMBOL(wrmsr_safe_regs_on_cpu);
280