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Commit 369e757b authored by Kumar Gala's avatar Kumar Gala
Browse files

[POWERPC] Rework EXC_LEVEL_EXCEPTION_PROLOG code 



* Cleanup the code a bit my allocating an INT_FRAME on our exception
  stack there by make references go from GPR11-INT_FRAME_SIZE(r8) to
  just GPR11(r8)
* simplify {lvl}_transfer_to_handler code by moving the copying of the
  temp registers we use if we come from user space into the PROLOG
* If the exception came from kernel mode copy thread_info flags,
  preempt, and task pointer from the process thread_info.

Signed-off-by: default avatarKumar Gala <galak@kernel.crashing.org>
Acked-by: default avatarPaul Mackerras <paulus@samba.org>
parent bcf0b088

arch/powerpc/kernel/entry_32.S

+0 −13
Original line number Diff line number Diff line
@@ -44,29 +44,16 @@ 
#endif



#ifdef CONFIG_BOOKE

#include "head_booke.h"

#define TRANSFER_TO_HANDLER_EXC_LEVEL(exc_level)	\

	mtspr	exc_level##_SPRG,r8;			\

	BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);		\

	lwz	r0,GPR10-INT_FRAME_SIZE(r8);		\

	stw	r0,GPR10(r11);				\

	lwz	r0,GPR11-INT_FRAME_SIZE(r8);		\

	stw	r0,GPR11(r11);				\

	mfspr	r8,exc_level##_SPRG



	.globl	mcheck_transfer_to_handler

mcheck_transfer_to_handler:

	TRANSFER_TO_HANDLER_EXC_LEVEL(MCHECK)

	b	transfer_to_handler_full



	.globl	debug_transfer_to_handler

debug_transfer_to_handler:

	TRANSFER_TO_HANDLER_EXC_LEVEL(DEBUG)

	b	transfer_to_handler_full



	.globl	crit_transfer_to_handler

crit_transfer_to_handler:

	TRANSFER_TO_HANDLER_EXC_LEVEL(CRIT)

	/* fall through */

#endif

arch/powerpc/kernel/head_booke.h

+35 −19
Original line number Diff line number Diff line
@@ -72,18 +72,20 @@ 
#define DEBUG_STACK_BASE	dbgirq_ctx

#define DEBUG_SPRG		SPRN_SPRG6W



#define EXC_LVL_FRAME_OVERHEAD	(THREAD_SIZE - INT_FRAME_SIZE)



#ifdef CONFIG_SMP

#define BOOKE_LOAD_EXC_LEVEL_STACK(level)		\

	mfspr	r8,SPRN_PIR;				\

	slwi	r8,r8,2;				\

	addis	r8,r8,level##_STACK_BASE@ha;		\

	lwz	r8,level##_STACK_BASE@l(r8);		\

	addi	r8,r8,THREAD_SIZE;

	addi	r8,r8,EXC_LVL_FRAME_OVERHEAD;

#else

#define BOOKE_LOAD_EXC_LEVEL_STACK(level)		\

	lis	r8,level##_STACK_BASE@ha;		\

	lwz	r8,level##_STACK_BASE@l(r8);		\

	addi	r8,r8,THREAD_SIZE;

	addi	r8,r8,EXC_LVL_FRAME_OVERHEAD;

#endif



/*
@@ -97,22 +99,36 @@ 
#define EXC_LEVEL_EXCEPTION_PROLOG(exc_level, exc_level_srr0, exc_level_srr1) \

	mtspr	exc_level##_SPRG,r8;					     \

	BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \

	stw	r10,GPR10-INT_FRAME_SIZE(r8);				     \

	stw	r11,GPR11-INT_FRAME_SIZE(r8);				     \

	mfcr	r10;			/* save CR in r10 for now	   */\

	mfspr	r11,exc_level_srr1;	/* check whether user or kernel    */\

	andi.	r11,r11,MSR_PR;						     \

	mr	r11,r8;							     \

	mfspr	r8,exc_level##_SPRG;					     \

	beq	1f;							     \

	/* COMING FROM USER MODE */					     \

	stw	r9,GPR9(r8);		/* save various registers	   */\

	mfcr	r9;			/* save CR in r9 for now	   */\

	stw	r10,GPR10(r8);						     \

	stw	r11,GPR11(r8);						     \

	stw	r9,_CCR(r8);		/* save CR on stack		   */\

	mfspr	r10,exc_level_srr1;	/* check whether user or kernel    */\

	andi.	r10,r10,MSR_PR;						     \

	mfspr	r11,SPRN_SPRG3;		/* if from user, start at top of   */\

	lwz	r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\

	addi	r11,r11,THREAD_SIZE;					     \

1:	subi	r11,r11,INT_FRAME_SIZE;	/* Allocate an exception frame     */\

	stw	r10,_CCR(r11);          /* save various registers	   */\

	stw	r12,GPR12(r11);						     \

	addi	r11,r11,EXC_LVL_FRAME_OVERHEAD;	/* allocate stack frame    */\

	beq	1f;							     \

	/* COMING FROM USER MODE */					     \

	stw	r9,_CCR(r11);		/* save CR			   */\

	lwz	r10,GPR10(r8);		/* copy regs from exception stack  */\

	lwz	r9,GPR9(r8);						     \

	stw	r10,GPR10(r11);						     \

	lwz	r10,GPR11(r8);						     \

	stw	r9,GPR9(r11);						     \

	stw	r10,GPR11(r11);						     \

	b	2f;							     \

	/* COMING FROM PRIV MODE */					     \

1:	lwz	r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r11);		     \

	lwz	r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r11);		     \

	stw	r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r8);			     \

	stw	r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r8);		     \

	lwz	r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r11);			     \

	stw	r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r8);			     \

	mr	r11,r8;							     \

2:	mfspr	r8,exc_level##_SPRG;					     \

	stw	r12,GPR12(r11);		/* save various registers	   */\

	mflr	r10;							     \

	stw	r10,_LINK(r11);						     \

	mfspr	r12,SPRN_DEAR;		/* save DEAR and ESR in the frame  */\
@@ -255,8 +271,8 @@ 
	lwz	r12,GPR12(r11);						      \

	mtspr	DEBUG_SPRG,r8;						      \

	BOOKE_LOAD_EXC_LEVEL_STACK(DEBUG); /* r8 points to the debug stack */ \

	lwz	r10,GPR10-INT_FRAME_SIZE(r8);				      \

	lwz	r11,GPR11-INT_FRAME_SIZE(r8);				      \

	lwz	r10,GPR10(r8);						      \

	lwz	r11,GPR11(r8);						      \

	mfspr	r8,DEBUG_SPRG;						      \

									      \

	RFDI;								      \
@@ -308,8 +324,8 @@ 
	lwz	r12,GPR12(r11);						      \

	mtspr	CRIT_SPRG,r8;						      \

	BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */  \

	lwz	r10,GPR10-INT_FRAME_SIZE(r8);				      \

	lwz	r11,GPR11-INT_FRAME_SIZE(r8);				      \

	lwz	r10,GPR10(r8);						      \

	lwz	r11,GPR11(r8);						      \

	mfspr	r8,CRIT_SPRG;						      \

									      \

	rfci;								      \