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![Eric Dumazet](/assets/img/avatar_default.png)
When changing rdmsr_safe_on_cpu() to schedule, it was missed that
__rdmsr_safe_on_cpu() was also used by rdmsrl_safe_on_cpu()
Make rdmsrl_safe_on_cpu() a wrapper instead of copy/pasting the code which
was added for the completion handling.
Fixes: 07cde313b2
("x86/msr: Allow rdmsr_safe_on_cpu() to schedule")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180328032233.153055-1-edumazet@google.com
280 lines
5.3 KiB
C
280 lines
5.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/export.h>
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#include <linux/preempt.h>
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#include <linux/smp.h>
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#include <linux/completion.h>
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#include <asm/msr.h>
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static void __rdmsr_on_cpu(void *info)
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{
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struct msr_info *rv = info;
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struct msr *reg;
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int this_cpu = raw_smp_processor_id();
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if (rv->msrs)
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reg = per_cpu_ptr(rv->msrs, this_cpu);
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else
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reg = &rv->reg;
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rdmsr(rv->msr_no, reg->l, reg->h);
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}
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static void __wrmsr_on_cpu(void *info)
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{
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struct msr_info *rv = info;
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struct msr *reg;
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int this_cpu = raw_smp_processor_id();
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if (rv->msrs)
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reg = per_cpu_ptr(rv->msrs, this_cpu);
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else
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reg = &rv->reg;
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wrmsr(rv->msr_no, reg->l, reg->h);
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}
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int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
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{
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int err;
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struct msr_info rv;
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memset(&rv, 0, sizeof(rv));
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rv.msr_no = msr_no;
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err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
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*l = rv.reg.l;
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*h = rv.reg.h;
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return err;
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}
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EXPORT_SYMBOL(rdmsr_on_cpu);
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int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
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{
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int err;
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struct msr_info rv;
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memset(&rv, 0, sizeof(rv));
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rv.msr_no = msr_no;
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err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
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*q = rv.reg.q;
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return err;
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}
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EXPORT_SYMBOL(rdmsrl_on_cpu);
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int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
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{
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int err;
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struct msr_info rv;
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memset(&rv, 0, sizeof(rv));
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rv.msr_no = msr_no;
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rv.reg.l = l;
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rv.reg.h = h;
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err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
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return err;
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}
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EXPORT_SYMBOL(wrmsr_on_cpu);
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int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
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{
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int err;
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struct msr_info rv;
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memset(&rv, 0, sizeof(rv));
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rv.msr_no = msr_no;
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rv.reg.q = q;
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err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
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return err;
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}
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EXPORT_SYMBOL(wrmsrl_on_cpu);
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static void __rwmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
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struct msr *msrs,
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void (*msr_func) (void *info))
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{
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struct msr_info rv;
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int this_cpu;
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memset(&rv, 0, sizeof(rv));
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rv.msrs = msrs;
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rv.msr_no = msr_no;
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this_cpu = get_cpu();
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if (cpumask_test_cpu(this_cpu, mask))
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msr_func(&rv);
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smp_call_function_many(mask, msr_func, &rv, 1);
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put_cpu();
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}
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/* rdmsr on a bunch of CPUs
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*
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* @mask: which CPUs
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* @msr_no: which MSR
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* @msrs: array of MSR values
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*
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*/
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void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
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{
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__rwmsr_on_cpus(mask, msr_no, msrs, __rdmsr_on_cpu);
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}
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EXPORT_SYMBOL(rdmsr_on_cpus);
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/*
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* wrmsr on a bunch of CPUs
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*
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* @mask: which CPUs
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* @msr_no: which MSR
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* @msrs: array of MSR values
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*
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*/
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void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
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{
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__rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu);
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}
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EXPORT_SYMBOL(wrmsr_on_cpus);
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struct msr_info_completion {
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struct msr_info msr;
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struct completion done;
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};
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/* These "safe" variants are slower and should be used when the target MSR
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may not actually exist. */
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static void __rdmsr_safe_on_cpu(void *info)
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{
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struct msr_info_completion *rv = info;
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rv->msr.err = rdmsr_safe(rv->msr.msr_no, &rv->msr.reg.l, &rv->msr.reg.h);
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complete(&rv->done);
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}
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static void __wrmsr_safe_on_cpu(void *info)
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{
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struct msr_info *rv = info;
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rv->err = wrmsr_safe(rv->msr_no, rv->reg.l, rv->reg.h);
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}
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int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
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{
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struct msr_info_completion rv;
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call_single_data_t csd = {
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.func = __rdmsr_safe_on_cpu,
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.info = &rv,
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};
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int err;
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memset(&rv, 0, sizeof(rv));
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init_completion(&rv.done);
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rv.msr.msr_no = msr_no;
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err = smp_call_function_single_async(cpu, &csd);
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if (!err) {
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wait_for_completion(&rv.done);
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err = rv.msr.err;
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}
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*l = rv.msr.reg.l;
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*h = rv.msr.reg.h;
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return err;
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}
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EXPORT_SYMBOL(rdmsr_safe_on_cpu);
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int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
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{
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int err;
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struct msr_info rv;
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memset(&rv, 0, sizeof(rv));
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rv.msr_no = msr_no;
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rv.reg.l = l;
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rv.reg.h = h;
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err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
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return err ? err : rv.err;
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}
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EXPORT_SYMBOL(wrmsr_safe_on_cpu);
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int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
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{
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int err;
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struct msr_info rv;
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memset(&rv, 0, sizeof(rv));
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rv.msr_no = msr_no;
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rv.reg.q = q;
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err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
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return err ? err : rv.err;
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}
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EXPORT_SYMBOL(wrmsrl_safe_on_cpu);
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int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
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{
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u32 low, high;
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int err;
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err = rdmsr_safe_on_cpu(cpu, msr_no, &low, &high);
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*q = (u64)high << 32 | low;
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return err;
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}
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EXPORT_SYMBOL(rdmsrl_safe_on_cpu);
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/*
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* These variants are significantly slower, but allows control over
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* the entire 32-bit GPR set.
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*/
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static void __rdmsr_safe_regs_on_cpu(void *info)
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{
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struct msr_regs_info *rv = info;
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rv->err = rdmsr_safe_regs(rv->regs);
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}
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static void __wrmsr_safe_regs_on_cpu(void *info)
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{
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struct msr_regs_info *rv = info;
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rv->err = wrmsr_safe_regs(rv->regs);
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}
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int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
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{
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int err;
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struct msr_regs_info rv;
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rv.regs = regs;
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rv.err = -EIO;
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err = smp_call_function_single(cpu, __rdmsr_safe_regs_on_cpu, &rv, 1);
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return err ? err : rv.err;
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}
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EXPORT_SYMBOL(rdmsr_safe_regs_on_cpu);
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int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
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{
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int err;
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struct msr_regs_info rv;
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rv.regs = regs;
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rv.err = -EIO;
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err = smp_call_function_single(cpu, __wrmsr_safe_regs_on_cpu, &rv, 1);
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return err ? err : rv.err;
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}
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EXPORT_SYMBOL(wrmsr_safe_regs_on_cpu);
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