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Commit 8dc4fd87 authored by Anton Blanchard's avatar Anton Blanchard Committed by Linus Torvalds
Browse files

[PATCH] ppc64: Turn runlatch on in exception entry 



Enable the runlatch at the start of each exception.  Unfortunately we are out
of space in the 0x300 handler, so I added it a bit later.

The SPR write is fairly expensive, perhaps we should cache the runlatch state
in the paca and avoid the write when possible.

We don't need to turn the runlatch off, we do that in the idle loop.  Better
to take the hit in the idle loop than for each exception exit.

Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent a2f7a9ce

arch/ppc64/kernel/head.S

+10 −0
Original line number Diff line number Diff line
@@ -308,6 +308,7 @@ exception_marker: 
label##_pSeries:					\

	HMT_MEDIUM;					\

	mtspr	SPRG1,r13;		/* save r13 */	\

	RUNLATCH_ON(r13);				\

	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)



#define STD_EXCEPTION_ISERIES(n, label, area)		\
@@ -315,6 +316,7 @@ label##_pSeries: \ 
label##_iSeries:					\

	HMT_MEDIUM;					\

	mtspr	SPRG1,r13;		/* save r13 */	\

	RUNLATCH_ON(r13);				\

	EXCEPTION_PROLOG_ISERIES_1(area);		\

	EXCEPTION_PROLOG_ISERIES_2;			\

	b	label##_common
@@ -324,6 +326,7 @@ label##_iSeries: \ 
label##_iSeries:							\

	HMT_MEDIUM;							\

	mtspr	SPRG1,r13;		/* save r13 */			\

	RUNLATCH_ON(r13);						\

	EXCEPTION_PROLOG_ISERIES_1(PACA_EXGEN);				\

	lbz	r10,PACAPROCENABLED(r13);				\

	cmpwi	0,r10,0;						\
@@ -393,6 +396,7 @@ __start_interrupts: 
_machine_check_pSeries:

	HMT_MEDIUM

	mtspr	SPRG1,r13		/* save r13 */

	RUNLATCH_ON(r13)

	EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)



	. = 0x300
@@ -419,6 +423,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_SLB) 
data_access_slb_pSeries:

	HMT_MEDIUM

	mtspr	SPRG1,r13

	RUNLATCH_ON(r13)

	mfspr	r13,SPRG3		/* get paca address into r13 */

	std	r9,PACA_EXSLB+EX_R9(r13)	/* save r9 - r12 */

	std	r10,PACA_EXSLB+EX_R10(r13)
@@ -439,6 +444,7 @@ data_access_slb_pSeries: 
instruction_access_slb_pSeries:

	HMT_MEDIUM

	mtspr	SPRG1,r13

	RUNLATCH_ON(r13)

	mfspr	r13,SPRG3		/* get paca address into r13 */

	std	r9,PACA_EXSLB+EX_R9(r13)	/* save r9 - r12 */

	std	r10,PACA_EXSLB+EX_R10(r13)
@@ -464,6 +470,7 @@ instruction_access_slb_pSeries: 
	.globl	system_call_pSeries

system_call_pSeries:

	HMT_MEDIUM

	RUNLATCH_ON(r9)

	mr	r9,r13

	mfmsr	r10

	mfspr	r13,SPRG3
@@ -707,11 +714,13 @@ fwnmi_data_area: 
system_reset_fwnmi:

	HMT_MEDIUM

	mtspr	SPRG1,r13		/* save r13 */

	RUNLATCH_ON(r13)

	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common)

	.globl machine_check_fwnmi

machine_check_fwnmi:

	HMT_MEDIUM

	mtspr	SPRG1,r13		/* save r13 */

	RUNLATCH_ON(r13)

	EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)



	/*
@@ -848,6 +857,7 @@ unrecov_fer: 
	.align	7

	.globl data_access_common

data_access_common:

	RUNLATCH_ON(r10)		/* It wont fit in the 0x300 handler */

	mfspr	r10,DAR

	std	r10,PACA_EXGEN+EX_DAR(r13)

	mfspr	r10,DSISR

include/asm-ppc64/processor.h

+9 −0
Original line number Diff line number Diff line
@@ -524,6 +524,15 @@ static inline void ppc64_runlatch_off(void) 


#endif /* __ASSEMBLY__ */



#ifdef __KERNEL__

#define RUNLATCH_ON(REG)			\

BEGIN_FTR_SECTION				\

	mfspr	(REG),SPRN_CTRLF;		\

	ori	(REG),(REG),CTRL_RUNLATCH;	\

	mtspr	SPRN_CTRLT,(REG);		\

END_FTR_SECTION_IFSET(CPU_FTR_CTRL)

#endif



/*

 * Number of entries in the SLB. If this ever changes we should handle

 * it with a use a cpu feature fixup.