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