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Commit 2eb2fd95 authored by LEROY Christophe's avatar LEROY Christophe Committed by Scott Wood
Browse files

powerpc/8xx: dont save CR in SCRATCH registers 



CR only needs to be preserved when checking if we are handling a kernel address.
So we can preserve CR in a register:
- In ITLBMiss, check is done only when CONFIG_MODULES is defined. Otherwise we
don't need to do anything at all with CR.
- We use r10, then we reload SRR0/MD_EPN into r10 when CR is restored

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent d5fd9d7d

arch/powerpc/kernel/head_8xx.S

+15 −14
Original line number Diff line number Diff line
@@ -312,10 +312,6 @@ InstructionTLBMiss: 
	mtspr	SPRN_DAR, r3

#endif

	EXCEPTION_PROLOG_0

	mfcr	r10

	mtspr	SPRN_SPRG_SCRATCH2, r10

	mfspr	r10, SPRN_SRR0	/* Get effective address of fault */

	INVALIDATE_ADJACENT_PAGES_CPU15(r11, r10)



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

	 * kernel page tables.
@@ -323,13 +319,20 @@ InstructionTLBMiss: 
#ifdef CONFIG_MODULES

	/* Only modules will cause ITLB Misses as we always

	 * pin the first 8MB of kernel memory */

	andis.	r11, r10, 0x8000	/* Address >= 0x80000000 */

#endif

	mfspr	r11, SPRN_SRR0	/* Get effective address of fault */

	INVALIDATE_ADJACENT_PAGES_CPU15(r10, r11)

	mfcr	r10

	andis.	r11, r11, 0x8000	/* Address >= 0x80000000 */

	mfspr	r11, SPRN_M_TW	/* Get level 1 table */

#ifdef CONFIG_MODULES

	beq	3f

	lis	r11, (swapper_pg_dir-PAGE_OFFSET)@ha

3:

	mtcr	r10

	mfspr	r10, SPRN_SRR0	/* Get effective address of fault */

#else

	mfspr	r10, SPRN_SRR0	/* Get effective address of fault */

	INVALIDATE_ADJACENT_PAGES_CPU15(r11, r10)

	mfspr	r11, SPRN_M_TW	/* Get level 1 table base address */

#endif

	/* Insert level 1 index */

	rlwimi	r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
@@ -362,8 +365,6 @@ InstructionTLBMiss: 
	mfspr	r3, SPRN_DAR

	mtspr	SPRN_DAR, r11	/* Tag DAR */

#endif

	mfspr	r10, SPRN_SPRG_SCRATCH2

	mtcr	r10

	EXCEPTION_EPILOG_0

	rfi
@@ -374,17 +375,19 @@ DataStoreTLBMiss: 
#endif

	EXCEPTION_PROLOG_0

	mfcr	r10

	mtspr	SPRN_SPRG_SCRATCH2, r10

	mfspr	r10, SPRN_MD_EPN



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

	 * kernel page tables.

	 */

	andis.	r11, r10, 0x8000

	mfspr	r11, SPRN_MD_EPN

	andis.	r11, r11, 0x8000

	mfspr	r11, SPRN_M_TW	/* Get level 1 table */

	beq	3f

	lis	r11, (swapper_pg_dir-PAGE_OFFSET)@ha

3:

	mtcr	r10

	mfspr	r10, SPRN_MD_EPN



	/* Insert level 1 index */

	rlwimi	r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29

	lwz	r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11)	/* Get the level 1 entry */
@@ -438,8 +441,6 @@ DataStoreTLBMiss: 
	mfspr	r3, SPRN_DAR

#endif

	mtspr	SPRN_DAR, r11	/* Tag DAR */

	mfspr	r10, SPRN_SPRG_SCRATCH2

	mtcr	r10

	EXCEPTION_EPILOG_0

	rfi