[PATCH] ARM: pt_regs offsets

Generate pt_regs S_xx offsets from the structure itself instead
of #defining them.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>

1 files changed, 10 insertions, 21 deletions

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 109f4f10d314..9d4d286d3808 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -39,30 +39,19 @@
 #define ARMSWI_OFFSET   0x000f0000
 
 @
-@ Stack format (ensured by USER_* and SVC_*)
+@ Most of the stack format comes from struct pt_regs, but with
+@ the addition of 8 bytes for storing syscall args 5 and 6.
 @
-#define S_FRAME_SIZE    72
-#define S_OLD_R0        68
-#define S_PSR           64
-
-#define S_PC            60
-#define S_LR            56
-#define S_SP            52
-#define S_IP            48
-#define S_FP            44
-#define S_R10           40
-#define S_R9            36
-#define S_R8            32
-#define S_R7            28
-#define S_R6            24
-#define S_R5            20
-#define S_R4            16
-#define S_R3            12
-#define S_R2            8
-#define S_R1            4
-#define S_R0            0
 #define S_OFF           8
 
+/* 
+ * The SWI code relies on the fact that R0 is at the bottom of the stack
+ * (due to slow/fast restore user regs).
+ */
+#if S_R0 != 0
+#error "Please fix"
+#endif
+
 #if __LINUX_ARM_ARCH__ >= 6
         .macro  disable_irq
         cpsid   i