Commit a8a12199 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/603: Don't handle kernel page TLB misses when not need 



ITLB miss on kernel pages only occur with CONFIG_MODULES and
CONFIG_DEBUG_PAGEALLOC.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 6790dae8

arch/powerpc/kernel/head_32.S

+4 −0
Original line number Diff line number Diff line
@@ -498,15 +498,19 @@ InstructionTLBMiss: 
 */

	/* Get PTE (linux-style) and check access */

	mfspr	r3,SPRN_IMISS

#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC)

	lis	r1,PAGE_OFFSET@h		/* check if kernel address */

	cmplw	0,r1,r3

#endif

	mfspr	r2, SPRN_SPRG_PGDIR

	li	r1,_PAGE_USER|_PAGE_PRESENT|_PAGE_EXEC /* low addresses tested as user */

#if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC)

	bge-	112f

	mfspr	r2,SPRN_SRR1		/* and MSR_PR bit from SRR1 */

	rlwimi	r1,r2,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */

	lis	r2, (swapper_pg_dir - PAGE_OFFSET)@ha	/* if kernel address, use */

	addi	r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l	/* kernel page table */

#endif

112:	rlwimi	r2,r3,12,20,29		/* insert top 10 bits of address */

	lwz	r2,0(r2)		/* get pmd entry */

	rlwinm.	r2,r2,0,0,19		/* extract address of pte page */

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