Commit bb9b5a83 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/8xx: remove EXCEPTION_PROLOG/EPILOG_0 and change r3 to r12 



EXCEPTION_PROLOG_0 and EXCEPTION_EPILOG_0 were added some
time ago in order to regroup the two mtspr/mfspr to SCRATCH0 and
SCRATCH1 and the mfcr/mtcr in order to ease entry and exit of
function not using the full EXCEPTION_PROLOG.

Since then, the mfcr/mtcr has been taken out, hence just leaving
the two mtspr/mfspr in the macro.

In order to improve readability of the exception functions, we
remove those two macros and copy back the two mtspr/mfspr instead.

As r10 and r11 are used for SCRATCH0 and SCRATCH1, lets also use
r12 for SCRATCH2. It will also improve the readability/maintenance.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 2a45addd

arch/powerpc/kernel/head_8xx.S

+40 −38
Original line number Diff line number Diff line
@@ -117,15 +117,12 @@ turn_on_mmu: 
 * task's thread_struct.

 */

#define EXCEPTION_PROLOG	\

	EXCEPTION_PROLOG_0;	\

	mtspr	SPRN_SPRG_SCRATCH0, r10;	\

	mtspr	SPRN_SPRG_SCRATCH1, r11;	\

	mfcr	r10;		\

	EXCEPTION_PROLOG_1;	\

	EXCEPTION_PROLOG_2



#define EXCEPTION_PROLOG_0	\

	mtspr	SPRN_SPRG_SCRATCH0,r10;	\

	mtspr	SPRN_SPRG_SCRATCH1,r11



#define EXCEPTION_PROLOG_1	\

	mfspr	r11,SPRN_SRR1;		/* check whether user or kernel */ \

	andi.	r11,r11,MSR_PR;	\
@@ -159,13 +156,6 @@ turn_on_mmu: 
	SAVE_4GPRS(3, r11);	\

	SAVE_2GPRS(7, r11)



/*

 * Exception exit code.

 */

#define EXCEPTION_EPILOG_0	\

	mfspr	r10,SPRN_SPRG_SCRATCH0;	\

	mfspr	r11,SPRN_SPRG_SCRATCH1



/*

 * Note: code which follows this uses cr0.eq (set if from kernel),

 * r11, r12 (SRR0), and r9 (SRR1).
@@ -309,10 +299,11 @@ SystemCall: 
#endif



InstructionTLBMiss:

	mtspr	SPRN_SPRG_SCRATCH0, r10

	mtspr	SPRN_SPRG_SCRATCH1, r11

#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)

	mtspr	SPRN_SPRG_SCRATCH2, r3

	mtspr	SPRN_SPRG_SCRATCH2, r12

#endif

	EXCEPTION_PROLOG_0

#ifdef CONFIG_PPC_8xx_PERF_EVENT

	lis	r10, (itlb_miss_counter - PAGE_OFFSET)@ha

	lwz	r11, (itlb_miss_counter - PAGE_OFFSET)@l(r10)
@@ -328,7 +319,7 @@ InstructionTLBMiss: 
	/* Only modules will cause ITLB Misses as we always

	 * pin the first 8MB of kernel memory */

#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)

	mfcr	r3

	mfcr	r12

#endif

#ifdef ITLB_MISS_KERNEL

#if defined(SIMPLE_KERNEL_ADDRESS) && defined(CONFIG_PIN_TLB_TEXT)
@@ -371,7 +362,7 @@ _ENTRY(ITLBMiss_cmp) 
	lwz	r10, 0(r10)	/* Get the pte */

4:

#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)

	mtcr	r3

	mtcr	r12

#endif

	/* Insert the APG into the TWC from the Linux PTE. */

	rlwimi	r11, r10, 0, 25, 26
@@ -401,10 +392,11 @@ _ENTRY(ITLBMiss_cmp) 
	mtspr	SPRN_MI_RPN, r10	/* Update TLB entry */



	/* Restore registers */

	mfspr	r10, SPRN_SPRG_SCRATCH0

	mfspr	r11, SPRN_SPRG_SCRATCH1

#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_HUGETLB_PAGE)

	mfspr	r3, SPRN_SPRG_SCRATCH2

	mfspr	r12, SPRN_SPRG_SCRATCH2

#endif

	EXCEPTION_EPILOG_0

	rfi



#ifdef CONFIG_HUGETLB_PAGE
@@ -434,15 +426,16 @@ _ENTRY(ITLBMiss_cmp) 


	. = 0x1200

DataStoreTLBMiss:

	mtspr	SPRN_SPRG_SCRATCH2, r3

	EXCEPTION_PROLOG_0

	mtspr	SPRN_SPRG_SCRATCH0, r10

	mtspr	SPRN_SPRG_SCRATCH1, r11

	mtspr	SPRN_SPRG_SCRATCH2, r12

#ifdef CONFIG_PPC_8xx_PERF_EVENT

	lis	r10, (dtlb_miss_counter - PAGE_OFFSET)@ha

	lwz	r11, (dtlb_miss_counter - PAGE_OFFSET)@l(r10)

	addi	r11, r11, 1

	stw	r11, (dtlb_miss_counter - PAGE_OFFSET)@l(r10)

#endif

	mfcr	r3

	mfcr	r12



	/* If we are faulting a kernel address, we have to use the

	 * kernel page tables.
@@ -482,7 +475,7 @@ _ENTRY(DTLBMiss_jmp) 
	rlwimi	r10, r11, 0, 0, 32 - PAGE_SHIFT - 1	/* Add level 2 base */

	lwz	r10, 0(r10)	/* Get the pte */

4:

	mtcr	r3

	mtcr	r12



	/* Insert the Guarded flag and APG into the TWC from the Linux PTE.

	 * It is bit 26-27 of both the Linux PTE and the TWC (at least
@@ -532,9 +525,10 @@ _ENTRY(DTLBMiss_jmp) 
	mtspr	SPRN_MD_RPN, r10	/* Update TLB entry */



	/* Restore registers */

	mfspr	r3, SPRN_SPRG_SCRATCH2

	mtspr	SPRN_DAR, r11	/* Tag DAR */

	EXCEPTION_EPILOG_0

	mfspr	r10, SPRN_SPRG_SCRATCH0

	mfspr	r11, SPRN_SPRG_SCRATCH1

	mfspr	r12, SPRN_SPRG_SCRATCH2

	rfi



#ifdef CONFIG_HUGETLB_PAGE
@@ -584,7 +578,8 @@ itlbie: 
 */

	. = 0x1400

DataTLBError:

	EXCEPTION_PROLOG_0

	mtspr	SPRN_SPRG_SCRATCH0, r10

	mtspr	SPRN_SPRG_SCRATCH1, r11

	mfcr	r10



	mfspr	r11, SPRN_DAR
@@ -619,7 +614,8 @@ dtlbie: 
 */

	. = 0x1c00

DataBreakpoint:

	EXCEPTION_PROLOG_0

	mtspr	SPRN_SPRG_SCRATCH0, r10

	mtspr	SPRN_SPRG_SCRATCH1, r11

	mfcr	r10

	mfspr	r11, SPRN_SRR0

	cmplwi	cr0, r11, (dtlbie - PAGE_OFFSET)@l
@@ -635,13 +631,15 @@ DataBreakpoint: 
	EXC_XFER_EE(0x1c00, do_break)

11:

	mtcr	r10

	EXCEPTION_EPILOG_0

	mfspr	r10, SPRN_SPRG_SCRATCH0

	mfspr	r11, SPRN_SPRG_SCRATCH1

	rfi



#ifdef CONFIG_PPC_8xx_PERF_EVENT

	. = 0x1d00

InstructionBreakpoint:

	EXCEPTION_PROLOG_0

	mtspr	SPRN_SPRG_SCRATCH0, r10

	mtspr	SPRN_SPRG_SCRATCH1, r11

	lis	r10, (instruction_counter - PAGE_OFFSET)@ha

	lwz	r11, (instruction_counter - PAGE_OFFSET)@l(r10)

	addi	r11, r11, -1
@@ -649,7 +647,8 @@ InstructionBreakpoint: 
	lis	r10, 0xffff

	ori	r10, r10, 0x01

	mtspr	SPRN_COUNTA, r10

	EXCEPTION_EPILOG_0

	mfspr	r10, SPRN_SPRG_SCRATCH0

	mfspr	r11, SPRN_SPRG_SCRATCH1

	rfi

#else

	EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_EE)
@@ -664,7 +663,7 @@ InstructionBreakpoint: 
 * not enough space in the DataStoreTLBMiss area.

 */

DTLBMissIMMR:

	mtcr	r3

	mtcr	r12

	/* Set 512k byte guarded page and mark it valid */

	li	r10, MD_PS512K | MD_GUARDED | MD_SVALID

	mtspr	SPRN_MD_TWC, r10
@@ -676,12 +675,13 @@ DTLBMissIMMR: 


	li	r11, RPN_PATTERN

	mtspr	SPRN_DAR, r11	/* Tag DAR */

	mfspr	r3, SPRN_SPRG_SCRATCH2

	EXCEPTION_EPILOG_0

	mfspr	r10, SPRN_SPRG_SCRATCH0

	mfspr	r11, SPRN_SPRG_SCRATCH1

	mfspr	r12, SPRN_SPRG_SCRATCH2

	rfi



DTLBMissLinear:

	mtcr	r3

	mtcr	r12

	/* Set 8M byte page and mark it valid */

	li	r11, MD_PS8MEG | MD_SVALID

	mtspr	SPRN_MD_TWC, r11
@@ -692,13 +692,14 @@ DTLBMissLinear: 


	li	r11, RPN_PATTERN

	mtspr	SPRN_DAR, r11	/* Tag DAR */

	mfspr	r3, SPRN_SPRG_SCRATCH2

	EXCEPTION_EPILOG_0

	mfspr	r10, SPRN_SPRG_SCRATCH0

	mfspr	r11, SPRN_SPRG_SCRATCH1

	mfspr	r12, SPRN_SPRG_SCRATCH2

	rfi



#ifndef CONFIG_PIN_TLB_TEXT

ITLBMissLinear:

	mtcr	r3

	mtcr	r12

	/* Set 8M byte page and mark it valid */

	li	r11, MI_PS8MEG | MI_SVALID | _PAGE_EXEC

	mtspr	SPRN_MI_TWC, r11
@@ -707,8 +708,9 @@ ITLBMissLinear: 
			  _PAGE_PRESENT

	mtspr	SPRN_MI_RPN, r10	/* Update TLB entry */



	mfspr	r3, SPRN_SPRG_SCRATCH2

	EXCEPTION_EPILOG_0

	mfspr	r10, SPRN_SPRG_SCRATCH0

	mfspr	r11, SPRN_SPRG_SCRATCH1

	mfspr	r12, SPRN_SPRG_SCRATCH2

	rfi

#endif

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