ARM: introduce svc_pt_regs structure

Since the privileged mode pt_regs are an extended version of the saved
userland pt_regs, introduce a new svc_pt_regs structure to describe this
layout.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 60d9c54..4eaea21 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -480,13 +480,13 @@
 	.macro	uaccess_save, tmp
 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
 	mrc	p15, 0, \tmp, c3, c0, 0
-	str	\tmp, [sp, #PT_REGS_SIZE]
+	str	\tmp, [sp, #SVC_DACR]
 #endif
 	.endm
 
 	.macro	uaccess_restore
 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
-	ldr	r0, [sp, #PT_REGS_SIZE]
+	ldr	r0, [sp, #SVC_DACR]
 	mcr	p15, 0, r0, c3, c0, 0
 #endif
 	.endm