x86, msr: Rewrite AMD rd/wrmsr variants

Switch them to native_{rd,wr}msr_safe_regs and remove
pv_cpu_ops.read_msr_amd.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
LKML-Reference: <1251705011-18636-2-git-send-email-petkovbb@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 21 insertions, 17 deletions

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 184d4a113961..09c5ca70d49d 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -71,22 +71,6 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr,
         return EAX_EDX_VAL(val, low, high);
 }
 
-static inline unsigned long long native_read_msr_amd_safe(unsigned int msr,
-                                                      int *err)
-{
-        DECLARE_ARGS(val, low, high);
-
-        asm volatile("2: rdmsr ; xor %0,%0\n"
-                     "1:\n\t"
-                     ".section .fixup,\"ax\"\n\t"
-                     "3:  mov %3,%0 ; jmp 1b\n\t"
-                     ".previous\n\t"
-                     _ASM_EXTABLE(2b, 3b)
-                     : "=r" (*err), EAX_EDX_RET(val, low, high)
-                     : "c" (msr), "D" (0x9c5a203a), "i" (-EFAULT));
-        return EAX_EDX_VAL(val, low, high);
-}
-
 static inline void native_write_msr(unsigned int msr,
                                     unsigned low, unsigned high)
 {
@@ -184,14 +168,34 @@ static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
         *p = native_read_msr_safe(msr, &err);
         return err;
 }
+
 static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
 {
+        u32 gprs[8] = { 0 };
         int err;
 
-        *p = native_read_msr_amd_safe(msr, &err);
+        gprs[1] = msr;
+        gprs[7] = 0x9c5a203a;
+
+        err = native_rdmsr_safe_regs(gprs);
+
+        *p = gprs[0] | ((u64)gprs[2] << 32);
+
         return err;
 }
 
+static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
+{
+        u32 gprs[8] = { 0 };
+
+        gprs[0] = (u32)val;
+        gprs[1] = msr;
+        gprs[2] = val >> 32;
+        gprs[7] = 0x9c5a203a;
+
+        return native_wrmsr_safe_regs(gprs);
+}
+
 static inline int rdmsr_safe_regs(u32 *regs)
 {
         return native_rdmsr_safe_regs(regs);