[PATCH] x86, msr: execute on the correct CPU subset

Borislav Petkov
2009-07-30T09:11:59Z

Make rdmsr_on_cpus/wrmsr_on_cpus execute on the current CPU only if it
is in the supplied bitmask.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
arch/x86/lib/msr.c | 26 ++++++++++----------------
1 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c
index 1440b9c..caa24ac 100644
--- a/arch/x86/lib/msr.c
+++ b/arch/x86/lib/msr.c
@@ -89,16 +89,13 @@ void rdmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs)
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);
+ this_cpu = get_cpu();
+
+ if (cpumask_test_cpu(this_cpu, mask))
+ __rdmsr_on_cpu(&rv);

smp_call_function_many(mask, __rdmsr_on_cpu, &rv, 1);
- preempt_enable();
+ put_cpu();
}
EXPORT_SYMBOL(rdmsr_on_cpus);

@@ -121,16 +118,13 @@ void wrmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs)
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);
+ this_cpu = get_cpu();
+
+ if (cpumask_test_cpu(this_cpu, mask))
+ __wrmsr_on_cpu(&rv);

smp_call_function_many(mask, __wrmsr_on_cpu, &rv, 1);
- preempt_enable();
+ put_cpu();
}
EXPORT_SYMBOL(wrmsr_on_cpus);

--
1.6.3.3