1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/export.h>
3 #include <linux/preempt.h>
5 #include <linux/completion.h>
8 static void __rdmsr_on_cpu(void *info)
10 struct msr_info *rv = info;
12 int this_cpu = raw_smp_processor_id();
15 reg = per_cpu_ptr(rv->msrs, this_cpu);
19 rdmsr(rv->msr_no, reg->l, reg->h);
22 static void __wrmsr_on_cpu(void *info)
24 struct msr_info *rv = info;
26 int this_cpu = raw_smp_processor_id();
29 reg = per_cpu_ptr(rv->msrs, this_cpu);
33 wrmsr(rv->msr_no, reg->l, reg->h);
36 int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
41 memset(&rv, 0, sizeof(rv));
44 err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
50 EXPORT_SYMBOL(rdmsr_on_cpu);
52 int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
57 memset(&rv, 0, sizeof(rv));
60 err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
65 EXPORT_SYMBOL(rdmsrl_on_cpu);
67 int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
72 memset(&rv, 0, sizeof(rv));
77 err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
81 EXPORT_SYMBOL(wrmsr_on_cpu);
83 int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
88 memset(&rv, 0, sizeof(rv));
93 err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
97 EXPORT_SYMBOL(wrmsrl_on_cpu);
99 static void __rwmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
101 void (*msr_func) (void *info))
106 memset(&rv, 0, sizeof(rv));
111 this_cpu = get_cpu();
113 if (cpumask_test_cpu(this_cpu, mask))
116 smp_call_function_many(mask, msr_func, &rv, 1);
120 /* rdmsr on a bunch of CPUs
124 * @msrs: array of MSR values
127 void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
129 __rwmsr_on_cpus(mask, msr_no, msrs, __rdmsr_on_cpu);
131 EXPORT_SYMBOL(rdmsr_on_cpus);
134 * wrmsr on a bunch of CPUs
138 * @msrs: array of MSR values
141 void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
143 __rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu);
145 EXPORT_SYMBOL(wrmsr_on_cpus);
147 struct msr_info_completion {
149 struct completion done;
152 /* These "safe" variants are slower and should be used when the target MSR
153 may not actually exist. */
154 static void __rdmsr_safe_on_cpu(void *info)
156 struct msr_info_completion *rv = info;
158 rv->msr.err = rdmsr_safe(rv->msr.msr_no, &rv->msr.reg.l, &rv->msr.reg.h);
162 static void __wrmsr_safe_on_cpu(void *info)
164 struct msr_info *rv = info;
166 rv->err = wrmsr_safe(rv->msr_no, rv->reg.l, rv->reg.h);
169 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
171 struct msr_info_completion rv;
172 call_single_data_t csd;
175 INIT_CSD(&csd, __rdmsr_safe_on_cpu, &rv);
177 memset(&rv, 0, sizeof(rv));
178 init_completion(&rv.done);
179 rv.msr.msr_no = msr_no;
181 err = smp_call_function_single_async(cpu, &csd);
183 wait_for_completion(&rv.done);
191 EXPORT_SYMBOL(rdmsr_safe_on_cpu);
193 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
198 memset(&rv, 0, sizeof(rv));
203 err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
205 return err ? err : rv.err;
207 EXPORT_SYMBOL(wrmsr_safe_on_cpu);
209 int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
214 memset(&rv, 0, sizeof(rv));
219 err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
221 return err ? err : rv.err;
223 EXPORT_SYMBOL(wrmsrl_safe_on_cpu);
225 int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
230 err = rdmsr_safe_on_cpu(cpu, msr_no, &low, &high);
231 *q = (u64)high << 32 | low;
235 EXPORT_SYMBOL(rdmsrl_safe_on_cpu);
238 * These variants are significantly slower, but allows control over
239 * the entire 32-bit GPR set.
241 static void __rdmsr_safe_regs_on_cpu(void *info)
243 struct msr_regs_info *rv = info;
245 rv->err = rdmsr_safe_regs(rv->regs);
248 static void __wrmsr_safe_regs_on_cpu(void *info)
250 struct msr_regs_info *rv = info;
252 rv->err = wrmsr_safe_regs(rv->regs);
255 int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
258 struct msr_regs_info rv;
262 err = smp_call_function_single(cpu, __rdmsr_safe_regs_on_cpu, &rv, 1);
264 return err ? err : rv.err;
266 EXPORT_SYMBOL(rdmsr_safe_regs_on_cpu);
268 int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
271 struct msr_regs_info rv;
275 err = smp_call_function_single(cpu, __wrmsr_safe_regs_on_cpu, &rv, 1);
277 return err ? err : rv.err;
279 EXPORT_SYMBOL(wrmsr_safe_regs_on_cpu);