3 files changed, 89 insertions, 7 deletions

diff --git a/arch/i386/lib/msr-on-cpu.c b/arch/i386/lib/msr-on-cpu.c
index 1c46bda409ff..7767962f25d3 100644
--- a/arch/i386/lib/msr-on-cpu.c
+++ b/arch/i386/lib/msr-on-cpu.c
@@ -6,6 +6,7 @@
 struct msr_info {
         u32 msr_no;
         u32 l, h;
+        int err;
 };
 
 static void __rdmsr_on_cpu(void *info)
@@ -15,20 +16,38 @@ static void __rdmsr_on_cpu(void *info)
         rdmsr(rv->msr_no, rv->l, rv->h);
 }
 
-void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+static void __rdmsr_safe_on_cpu(void *info)
 {
+        struct msr_info *rv = info;
+
+        rv->err = rdmsr_safe(rv->msr_no, &rv->l, &rv->h);
+}
+
+static int _rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h, int safe)
+{
+        int err = 0;
         preempt_disable();
         if (smp_processor_id() == cpu)
-                rdmsr(msr_no, *l, *h);
+                if (safe)
+                        err = rdmsr_safe(msr_no, l, h);
+                else
+                        rdmsr(msr_no, *l, *h);
         else {
                 struct msr_info rv;
 
                 rv.msr_no = msr_no;
-                smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 0, 1);
+                if (safe) {
+                        smp_call_function_single(cpu, __rdmsr_safe_on_cpu,
+                                                 &rv, 0, 1);
+                        err = rv.err;
+                } else {
+                        smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 0, 1);
+                }
                 *l = rv.l;
                 *h = rv.h;
         }
         preempt_enable();
+        return err;
 }
 
 static void __wrmsr_on_cpu(void *info)
@@ -38,21 +57,63 @@ static void __wrmsr_on_cpu(void *info)
         wrmsr(rv->msr_no, rv->l, rv->h);
 }
 
-void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+static void __wrmsr_safe_on_cpu(void *info)
 {
+        struct msr_info *rv = info;
+
+        rv->err = wrmsr_safe(rv->msr_no, rv->l, rv->h);
+}
+
+static int _wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h, int safe)
+{
+        int err = 0;
         preempt_disable();
         if (smp_processor_id() == cpu)
-                wrmsr(msr_no, l, h);
+                if (safe)
+                        err = wrmsr_safe(msr_no, l, h);
+                else
+                        wrmsr(msr_no, l, h);
         else {
                 struct msr_info rv;
 
                 rv.msr_no = msr_no;
                 rv.l = l;
                 rv.h = h;
-                smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 0, 1);
+                if (safe) {
+                        smp_call_function_single(cpu, __wrmsr_safe_on_cpu,
+                                                 &rv, 0, 1);
+                        err = rv.err;
+                } else {
+                        smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 0, 1);
+                }
         }
         preempt_enable();
+        return err;
+}
+
+void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+{
+        _wrmsr_on_cpu(cpu, msr_no, l, h, 0);
+}
+
+void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+{
+        _rdmsr_on_cpu(cpu, msr_no, l, h, 0);
+}
+
+/* These "safe" variants are slower and should be used when the target MSR
+   may not actually exist. */
+int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+{
+        return _wrmsr_on_cpu(cpu, msr_no, l, h, 1);
+}
+
+int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+{
+        return _rdmsr_on_cpu(cpu, msr_no, l, h, 1);
 }
 
 EXPORT_SYMBOL(rdmsr_on_cpu);
 EXPORT_SYMBOL(wrmsr_on_cpu);
+EXPORT_SYMBOL(rdmsr_safe_on_cpu);
+EXPORT_SYMBOL(wrmsr_safe_on_cpu);
diff --git a/include/asm-i386/msr.h b/include/asm-i386/msr.h
index 9559894c7658..26861df52cc4 100644
--- a/include/asm-i386/msr.h
+++ b/include/asm-i386/msr.h
@@ -77,7 +77,7 @@ static inline unsigned long long native_read_pmc(void)
 #ifdef CONFIG_PARAVIRT
 #include <asm/paravirt.h>
 #else
-
+#include <linux/errno.h>
 /*
  * Access to machine-specific registers (available on 586 and better only)
  * Note: the rd* operations modify the parameters directly (without using
@@ -148,6 +148,8 @@ static inline void wrmsrl (unsigned long msr, unsigned long long val)
 #ifdef CONFIG_SMP
 void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
+int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
+int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 #else  /*  CONFIG_SMP  */
 static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
 {
@@ -157,6 +159,14 @@ static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 {
         wrmsr(msr_no, l, h);
 }
+static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+{
+        return rdmsr_safe(msr_no, l, h);
+}
+static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+{
+        return wrmsr_safe(msr_no, l, h);
+}
 #endif  /*  CONFIG_SMP  */
 #endif
 #endif
diff --git a/include/asm-x86_64/msr.h b/include/asm-x86_64/msr.h
index a524f0325673..d5c55b80da54 100644
--- a/include/asm-x86_64/msr.h
+++ b/include/asm-x86_64/msr.h
@@ -4,6 +4,7 @@
 #include <asm/msr-index.h>
 
 #ifndef __ASSEMBLY__
+#include <linux/errno.h>
 /*
  * Access to machine-specific registers (available on 586 and better only)
  * Note: the rd* operations modify the parameters directly (without using
@@ -162,6 +163,8 @@ static inline unsigned int cpuid_edx(unsigned int op)
 #ifdef CONFIG_SMP
 void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
+int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
+int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 #else  /*  CONFIG_SMP  */
 static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
 {
@@ -171,6 +174,14 @@ static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 {
         wrmsr(msr_no, l, h);
 }
+static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+{
+        return rdmsr_safe(msr_no, l, h);
+}
+static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+{
+        return wrmsr_safe(msr_no, l, h);
+}
 #endif  /* CONFIG_SMP */
 #endif /* __ASSEMBLY__ */
 #endif  /* X86_64_MSR_H */