diff options
Diffstat (limited to 'arch/x86/lib/msr.c')
| -rw-r--r-- | arch/x86/lib/msr.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c new file mode 100644 index 00000000000..1440b9c0547 --- /dev/null +++ b/arch/x86/lib/msr.c @@ -0,0 +1,183 @@ +#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; + + preempt_disable(); + /* + * FIXME: handle the CPU we're executing on separately for now until + * smp_call_function_many has been fixed to not skip it. + */ + this_cpu = raw_smp_processor_id(); + smp_call_function_single(this_cpu, __rdmsr_on_cpu, &rv, 1); + + smp_call_function_many(mask, __rdmsr_on_cpu, &rv, 1); + preempt_enable(); +} +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; + + preempt_disable(); + /* + * FIXME: handle the CPU we're executing on separately for now until + * smp_call_function_many has been fixed to not skip it. + */ + this_cpu = raw_smp_processor_id(); + smp_call_function_single(this_cpu, __wrmsr_on_cpu, &rv, 1); + + smp_call_function_many(mask, __wrmsr_on_cpu, &rv, 1); + preempt_enable(); +} +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); |