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authorBorislav Petkov <borislav.petkov@amd.com>2009-05-22 13:52:19 +0200
committerBorislav Petkov <borislav.petkov@amd.com>2009-06-10 12:18:43 +0200
commitb034c19f9f61c8b6f2435aa2e77f52348ebde767 (patch)
tree0dce206e1eaa998b7233a4679e366890881c1f7f /arch/x86/lib
parent6bc1096d7ab3621b3ffcf06616d1f4e0325d903d (diff)
x86: MSR: add methods for writing of an MSR on several CPUs
Provide for concurrent MSR writes on all the CPUs in the cpumask. Also, add a temporary workaround for smp_call_function_many which skips the CPU we're executing on. Bart: zero out rv struct which is allocated on stack. CC: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/msr.c98
1 files changed, 92 insertions, 6 deletions
diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c
index cade714e57f..1440b9c0547 100644
--- a/arch/x86/lib/msr.c
+++ b/arch/x86/lib/msr.c
@@ -6,21 +6,37 @@
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();
- rdmsr(rv->msr_no, rv->reg.l, rv->reg.h);
+ 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, rv->reg.l, rv->reg.h);
+ wrmsr(rv->msr_no, reg->l, reg->h);
}
int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
@@ -28,6 +44,8 @@ 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;
@@ -35,12 +53,15 @@ int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *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;
@@ -48,6 +69,70 @@ int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
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. */
@@ -70,6 +155,8 @@ 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;
@@ -77,12 +164,15 @@ int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *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;
@@ -90,8 +180,4 @@ int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
return err ? err : rv.err;
}
-
-EXPORT_SYMBOL(rdmsr_on_cpu);
-EXPORT_SYMBOL(wrmsr_on_cpu);
-EXPORT_SYMBOL(rdmsr_safe_on_cpu);
EXPORT_SYMBOL(wrmsr_safe_on_cpu);