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Commit 061ec959 authored by Joakim Tjernlund's avatar Joakim Tjernlund Committed by Benjamin Herrenschmidt
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powerpc/8xx: Fix user space TLB walk in dcbX fixup 



The newly added fixup for buggy dcbX insn's has
a bug that always trigger a kernel TLB walk so a user space
dcbX insn will cause a Kernel Machine Check if it hits DTLB error.

Signed-off-by: default avatarJoakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 3e7b4843

arch/powerpc/kernel/head_8xx.S

+2 −2
Original line number Diff line number Diff line
@@ -542,11 +542,11 @@ DARFixed:/* Return from dcbx instruction bug workaround, r10 holds value of DAR 
FixupDAR:/* Entry point for dcbx workaround. */

	/* fetch instruction from memory. */

	mfspr	r10, SPRN_SRR0

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

	DO_8xx_CPU6(0x3780, r3)

	mtspr	SPRN_MD_EPN, r10

	mfspr	r11, SPRN_M_TWB	/* Get level 1 table entry address */

	cmplwi	cr0, r11, 0x0800

	blt-	3f		/* Branch if user space */

	beq-	3f		/* Branch if user space */

	lis	r11, (swapper_pg_dir-PAGE_OFFSET)@h

	ori	r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l

	rlwimi	r11, r10, 32-20, 0xffc /* r11 = r11&~0xffc|(r10>>20)&0xffc */