x86: introduce __ASM_REG macro.

There are situations in which the architecture wants to use the
register that represents its word-size, whatever it is. For those,
introduce __ASM_REG in asm.h, along with the first users _ASM_AX
and _ASM_DX. They have users waiting for it, namely the getuser
functions.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 18 insertions, 18 deletions

diff --git a/arch/x86/lib/getuser_64.S b/arch/x86/lib/getuser_64.S
index 6134752a75fd..63b0e5c1e582 100644
--- a/arch/x86/lib/getuser_64.S
+++ b/arch/x86/lib/getuser_64.S
@@ -13,14 +13,13 @@
 /*
  * __get_user_X
  *
- * Inputs:      %rcx contains the address.
+ * Inputs:      %rax contains the address.
  *              The register is modified, but all changes are undone
  *              before returning because the C code doesn't know about it.
  *
  * Outputs:     %rax is error code (0 or -EFAULT)
  *              %rdx contains zero-extended value
  * 
- * %r8 is destroyed.
  *
  * These functions should not modify any other registers,
  * as they get called from within inline assembly.
@@ -32,14 +31,15 @@
 #include <asm/errno.h>
 #include <asm/asm-offsets.h>
 #include <asm/thread_info.h>
+#include <asm/asm.h>
 
         .text
 ENTRY(__get_user_1)
         CFI_STARTPROC
-        GET_THREAD_INFO(%rdx)
-        cmp TI_addr_limit(%rdx),%rax
+        GET_THREAD_INFO(%_ASM_DX)
+        cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
         jae bad_get_user
-1:      movzb (%rax),%edx
+1:      movzb (%_ASM_AX),%edx
         xor %eax,%eax
         ret
         CFI_ENDPROC
@@ -47,12 +47,12 @@ ENDPROC(__get_user_1)
 
 ENTRY(__get_user_2)
         CFI_STARTPROC
-        add $1,%rax
+        add $1,%_ASM_AX
         jc bad_get_user
-        GET_THREAD_INFO(%rdx)
-        cmp TI_addr_limit(%rdx),%rax
+        GET_THREAD_INFO(%_ASM_DX)
+        cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
         jae bad_get_user
-2:      movzwl -1(%rax),%edx
+2:      movzwl -1(%_ASM_AX),%edx
         xor %eax,%eax
         ret
         CFI_ENDPROC
@@ -60,12 +60,12 @@ ENDPROC(__get_user_2)
 
 ENTRY(__get_user_4)
         CFI_STARTPROC
-        add $3,%rax
+        add $3,%_ASM_AX
         jc bad_get_user
-        GET_THREAD_INFO(%rdx)
-        cmp TI_addr_limit(%rdx),%rax
+        GET_THREAD_INFO(%_ASM_DX)
+        cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
         jae bad_get_user
-3:      mov -3(%rax),%edx
+3:      mov -3(%_ASM_AX),%edx
         xor %eax,%eax
         ret
         CFI_ENDPROC
@@ -73,12 +73,12 @@ ENDPROC(__get_user_4)
 
 ENTRY(__get_user_8)
         CFI_STARTPROC
-        add $7,%rax
+        add $7,%_ASM_AX
         jc bad_get_user
-        GET_THREAD_INFO(%rdx)
-        cmp TI_addr_limit(%rdx),%rax
+        GET_THREAD_INFO(%_ASM_DX)
+        cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
         jae     bad_get_user
-4:      movq -7(%rax),%rdx
+4:      movq -7(%_ASM_AX),%_ASM_DX
         xor %eax,%eax
         ret
         CFI_ENDPROC
@@ -87,7 +87,7 @@ ENDPROC(__get_user_8)
 bad_get_user:
         CFI_STARTPROC
         xor %edx,%edx
-        mov $(-EFAULT),%rax
+        mov $(-EFAULT),%_ASM_AX
         ret
         CFI_ENDPROC
 END(bad_get_user)