Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits)
  x86: Fix code patching for paravirt-alternatives on 486
  x86, msr: change msr-reg.o to obj-y, and export its symbols
  x86: Use hard_smp_processor_id() to get apic id for AMD K8 cpus
  x86, sched: Workaround broken sched domain creation for AMD Magny-Cours
  x86, mcheck: Use correct cpumask for shared bank4
  x86, cacheinfo: Fixup L3 cache information for AMD multi-node processors
  x86: Fix CPU llc_shared_map information for AMD Magny-Cours
  x86, msr: Fix msr-reg.S compilation with gas 2.16.1, on 32-bit too
  x86: Move kernel_fpu_using to irq_fpu_usable in asm/i387.h
  x86, msr: fix msr-reg.S compilation with gas 2.16.1
  x86, msr: Export the register-setting MSR functions via /dev/*/msr
  x86, msr: Create _on_cpu helpers for {rw,wr}msr_safe_regs()
  x86, msr: Have the _safe MSR functions return -EIO, not -EFAULT
  x86, msr: CFI annotations, cleanups for msr-reg.S
  x86, asm: Make _ASM_EXTABLE() usable from assembly code
  x86, asm: Add 32-bit versions of the combined CFI macros
  x86, AMD: Disable wrongly set X86_FEATURE_LAHF_LM CPUID bit
  x86, msr: Rewrite AMD rd/wrmsr variants
  x86, msr: Add rd/wrmsr interfaces with preset registers
  x86: add specific support for Intel Atom architecture
  ...

1 files changed, 49 insertions, 0 deletions

diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c
index caa24aca8115..33a1e3ca22d8 100644
--- a/arch/x86/lib/msr.c
+++ b/arch/x86/lib/msr.c
@@ -175,3 +175,52 @@ int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
 	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);