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Commit 48cc95d4 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Greg Kroah-Hartman
Browse files

powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL 



commit c7305645eb0c1621351cfc104038831ae87c0053 upstream.

In the SLB miss handler we may be returning to user or kernel. We need
to add a check early on and save the result in the cr4 register, and
then we bifurcate the return path based on that.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
[mpe: Backport to 4.4 based on patch from Balbir]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 00e40620

arch/powerpc/kernel/exceptions-64s.S

+20 −2
Original line number Diff line number Diff line
@@ -655,6 +655,8 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) 


	andi.	r10,r12,MSR_RI	/* check for unrecoverable exception */

	beq-	2f

	andi.	r10,r12,MSR_PR	/* check for user mode (PR != 0) */

	bne	1f



	/* All done -- return from exception. */
@@ -671,7 +673,23 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) 
	ld	r11,PACA_EXSLB+EX_R11(r13)

	ld	r12,PACA_EXSLB+EX_R12(r13)

	ld	r13,PACA_EXSLB+EX_R13(r13)

	rfid

	RFI_TO_KERNEL

	b	.	/* prevent speculative execution */



1:

.machine	push

.machine	"power4"

	mtcrf	0x80,r9

	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */

.machine	pop



	RESTORE_PPR_PACA(PACA_EXSLB, r9)

	ld	r9,PACA_EXSLB+EX_R9(r13)

	ld	r10,PACA_EXSLB+EX_R10(r13)

	ld	r11,PACA_EXSLB+EX_R11(r13)

	ld	r12,PACA_EXSLB+EX_R12(r13)

	ld	r13,PACA_EXSLB+EX_R13(r13)

	RFI_TO_USER

	b	.	/* prevent speculative execution */



2:	mfspr	r11,SPRN_SRR0
@@ -679,7 +697,7 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) 
	mtspr	SPRN_SRR0,r10

	ld	r10,PACAKMSR(r13)

	mtspr	SPRN_SRR1,r10

	rfid

	RFI_TO_KERNEL

	b	.



8:	mfspr	r11,SPRN_SRR0