locore: Also factorize segment management on i386

and harmonize i386/x86_64.

This btw fixes not using dx in 32-on-64's alltraps.

1 files changed, 52 insertions, 72 deletions

diff --git a/i386/i386/locore.S b/i386/i386/locore.S
index 846f5567..be412af0 100644
--- a/i386/i386/locore.S
+++ b/i386/i386/locore.S
@@ -40,6 +40,44 @@
 #include <i386/xen.h>
 
 /*
+ * Note that we have to load the kernel segment registers even if this
+ * is a trap from the kernel, because the kernel uses user segment
+ * registers for copyin/copyout.
+ * (XXX Would it be smarter just to use fs or gs for that?)
+ */
+#define PUSH_SEGMENTS	\
+	pushl	%ds		;\
+	pushl	%es		;\
+	pushl	%fs		;\
+	pushl	%gs
+
+#define POP_SEGMENTS	\
+	popl	%gs		;\
+	popl	%fs		;\
+	popl	%es		;\
+	popl	%ds
+
+#define PUSH_SEGMENTS_ISR	\
+	pushl	%ds		;\
+	pushl	%es		;\
+	pushl	%fs		;\
+	pushl	%gs
+
+#define POP_SEGMENTS_ISR	\
+	popl	%gs		;\
+	popl	%fs		;\
+	popl	%es		;\
+	popl	%ds
+
+#define SET_KERNEL_SEGMENTS(reg)	       \
+	mov	%ss,reg /* switch to kernel segments */ ;\
+	mov	reg,%ds	/* (same as kernel stack segment) */ ;\
+	mov	reg,%es			;\
+	mov	reg,%fs			;\
+	mov	$(PERCPU_DS),reg	;\
+	mov	reg,%gs
+
+/*
  * Fault recovery.
  */
 #define	RECOVER_TABLE_START	\
@@ -456,22 +494,8 @@ ENTRY(t_page_fault)
 ENTRY(alltraps)
 	pusha				/* save the general registers */
 trap_push_segs:
-	pushl	%ds			/* and the segment registers */
-	pushl	%es
-	pushl	%fs
-	pushl	%gs
-
-	/* Note that we have to load the segment registers
-	   even if this is a trap from the kernel,
-	   because the kernel uses user segment registers for copyin/copyout.
-	   (XXX Would it be smarter just to use fs or gs for that?)  */
-	mov	%ss,%ax			/* switch to kernel data segment */
-	mov	%ax,%ds			/* (same as kernel stack segment) */
-	mov	%ax,%es
-	mov	%ax,%fs
-	mov	$(PERCPU_DS),%ax
-	movw	%ax,%gs
-
+	PUSH_SEGMENTS			/* and the segment registers */
+	SET_KERNEL_SEGMENTS(%ax)	/* switch to kernel data segment */
 trap_set_segs:
 	cld				/* clear direction flag */
 	testl	$(EFL_VM),R_EFLAGS(%esp) /* in V86 mode? */
@@ -680,16 +704,8 @@ ENTRY(all_intrs)
 	cmpl	%ss:CX(EXT(int_stack_base),%ecx),%edx
 	je	int_from_intstack	/* if not: */
 
-	pushl	%ds			/* save segment registers */
-	pushl	%es
-	pushl	%fs
-	pushl	%gs
-	mov	%ss,%dx			/* switch to kernel segments */
-	mov	%dx,%ds
-	mov	%dx,%es
-	mov	%dx,%fs
-	mov	$(PERCPU_DS),%dx
-	movw	%dx,%gs
+	PUSH_SEGMENTS_ISR		/* save segment registers */
+	SET_KERNEL_SEGMENTS(%dx)	/* switch to kernel segments */
 
 	CPU_NUMBER(%edx)
 
@@ -737,10 +753,7 @@ LEXT(return_to_iret)			/* to find the return from calling interrupt) */
 	cmpl	$0,CX(EXT(need_ast),%edx)
 	jnz	ast_from_interrupt	/* take it if so */
 1:
-	pop	%gs			/* restore segment regs */
-	pop	%fs
-	pop	%es
-	pop	%ds
+	POP_SEGMENTS_ISR		/* restore segment regs */
 	pop	%edx
 	pop	%ecx
 	pop	%eax
@@ -777,27 +790,15 @@ stack_overflowed:
  *	ss
  */
 ast_from_interrupt:
-	pop	%gs			/* restore all registers ... */
-	pop	%fs
-	pop	%es
-	pop	%ds
+	POP_SEGMENTS_ISR		/* restore all registers ... */
 	popl	%edx
 	popl	%ecx
 	popl	%eax
 	pushl	$0			/* zero code */
 	pushl	$0			/* zero trap number */
 	pusha				/* save general registers */
-	push	%ds			/* save segment registers */
-	push	%es
-	push	%fs
-	push	%gs
-	mov	%ss,%dx			/* switch to kernel segments */
-	mov	%dx,%ds
-	mov	%dx,%es
-	mov	%dx,%fs
-	mov	$(PERCPU_DS),%dx
-	movw	%dx,%gs
-
+	PUSH_SEGMENTS_ISR		/* save segment registers */
+	SET_KERNEL_SEGMENTS(%dx)	/* switch to kernel segments */
 	CPU_NUMBER(%edx)
 	TIME_TRAP_UENTRY
 
@@ -924,19 +925,13 @@ kdb_from_iret_i:			/* on interrupt stack */
 	pushl	$0			/* zero error code */
 	pushl	$0			/* zero trap number */
 	pusha				/* save general registers */
-	push	%ds			/* save segment registers */
-	push	%es
-	push	%fs
-	push	%gs
+	PUSH_SEGMENTS			/* save segment registers */
 	pushl	%esp			/* pass regs, */
 	pushl	$0			/* code, */
 	pushl	$-1			/* type to kdb */
 	call	EXT(kdb_trap)
 	addl	$12,%esp		/* remove parameters */
-	pop	%gs			/* restore segment registers */
-	pop	%fs
-	pop	%es
-	pop	%ds
+	POP_SEGMENTS			/* restore segment registers */
 	popa				/* restore general registers */
 	addl	$8,%esp
 	iret
@@ -1006,19 +1001,13 @@ ttd_from_iret_i:			/* on interrupt stack */
 	pushl	$0			/* zero error code */
 	pushl	$0			/* zero trap number */
 	pusha				/* save general registers */
-	push	%ds			/* save segment registers */
-	push	%es
-	push	%fs
-	push	%gs
+	PUSH_SEGMENTS_ISR		/* save segment registers */
 	pushl	%esp			/* pass regs, */
 	pushl	$0			/* code, */
 	pushl	$-1			/* type to kdb */
 	call	_kttd_trap
 	addl	$12,%esp		/* remove parameters */
-	pop	%gs			/* restore segment registers */
-	pop	%fs
-	pop	%es
-	pop	%ds
+	POP_SEGMENTS_ISR		/* restore segment registers */
 	popa				/* restore general registers */
 	addl	$8,%esp
 	iret
@@ -1046,17 +1035,8 @@ syscall_entry_2:
 	pushl	$0			/* clear trap number slot */
 
 	pusha				/* save the general registers */
-	pushl	%ds			/* and the segment registers */
-	pushl	%es
-	pushl	%fs
-	pushl	%gs
-
-	mov	%ss,%dx			/* switch to kernel data segment */
-	mov	%dx,%ds
-	mov	%dx,%es
-	mov	%dx,%fs
-	mov	$(PERCPU_DS),%dx
-	movw	%dx,%gs
+	PUSH_SEGMENTS			/* and the segment registers */
+	SET_KERNEL_SEGMENTS(%dx)	/* switch to kernel data segment */
 
 /*
  * Shuffle eflags,eip,cs into proper places