x86, msr: Create _on_cpu helpers for {rw,wr}msr_safe_regs()
Create _on_cpu helpers for {rw,wr}msr_safe_regs() analogously with the
other MSR functions. This will be necessary to add support for these
to the MSR driver.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <petkovbb@gmail.com>
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 943fdd5..8e56712 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -97,8 +97,8 @@
extern unsigned long long native_read_tsc(void);
-extern int native_rdmsr_safe_regs(u32 *regs);
-extern int native_wrmsr_safe_regs(u32 *regs);
+extern int native_rdmsr_safe_regs(u32 regs[8]);
+extern int native_wrmsr_safe_regs(u32 regs[8]);
static __always_inline unsigned long long __native_read_tsc(void)
{
@@ -196,12 +196,12 @@
return native_wrmsr_safe_regs(gprs);
}
-static inline int rdmsr_safe_regs(u32 *regs)
+static inline int rdmsr_safe_regs(u32 regs[8])
{
return native_rdmsr_safe_regs(regs);
}
-static inline int wrmsr_safe_regs(u32 *regs)
+static inline int wrmsr_safe_regs(u32 regs[8])
{
return native_wrmsr_safe_regs(regs);
}
@@ -245,6 +245,8 @@
void wrmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs);
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);
+int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
+int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
#else /* CONFIG_SMP */
static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
@@ -275,6 +277,14 @@
{
return wrmsr_safe(msr_no, l, h);
}
+static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
+{
+ return rdmsr_safe_regs(regs);
+}
+static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
+{
+ return wrmsr_safe_regs(regs);
+}
#endif /* CONFIG_SMP */
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c
index caa24ac..33a1e3c 100644
--- a/arch/x86/lib/msr.c
+++ b/arch/x86/lib/msr.c
@@ -175,3 +175,52 @@
return err ? err : rv.err;
}
EXPORT_SYMBOL(wrmsr_safe_on_cpu);
+
+/*
+ * These variants are significantly slower, but allows control over
+ * the entire 32-bit GPR set.
+ */
+struct msr_regs_info {
+ u32 *regs;
+ int err;
+};
+
+static void __rdmsr_safe_regs_on_cpu(void *info)
+{
+ struct msr_regs_info *rv = info;
+
+ rv->err = rdmsr_safe_regs(rv->regs);
+}
+
+static void __wrmsr_safe_regs_on_cpu(void *info)
+{
+ struct msr_regs_info *rv = info;
+
+ rv->err = wrmsr_safe_regs(rv->regs);
+}
+
+int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
+{
+ int err;
+ struct msr_regs_info rv;
+
+ rv.regs = regs;
+ rv.err = -EIO;
+ err = smp_call_function_single(cpu, __rdmsr_safe_regs_on_cpu, &rv, 1);
+
+ return err ? err : rv.err;
+}
+EXPORT_SYMBOL(rdmsr_safe_regs_on_cpu);
+
+int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
+{
+ int err;
+ struct msr_regs_info rv;
+
+ rv.regs = regs;
+ rv.err = -EIO;
+ err = smp_call_function_single(cpu, __wrmsr_safe_regs_on_cpu, &rv, 1);
+
+ return err ? err : rv.err;
+}
+EXPORT_SYMBOL(wrmsr_safe_regs_on_cpu);