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Commit b0a779de authored by Paul Mackerras's avatar Paul Mackerras
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[POWERPC] Make sure interrupt enable gets restored properly 



The lazy IRQ disable patch missed a couple of places where the
interrupt enable flags need to be restored correctly.  First, we
weren't restoring the paca->hard_enabled flag on interrupt exit.
Instead of saving it on entry, we compute it from the MSR_EE bit
in the MSR we are restoring at exit.  Secondly, the MMU hash miss
code was clearing both paca->soft_enabled and paca->hard_enabled
but not restoring them in the case where hash_page was able to
resolve the miss from the Linux page tables.

Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 035223fb

arch/powerpc/kernel/entry_64.S

+4 −0
Original line number Diff line number Diff line
@@ -489,6 +489,10 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES) 
	andi.	r0,r3,MSR_RI

	beq-	unrecov_restore



	/* extract EE bit and use it to restore paca->hard_enabled */

	rldicl	r4,r3,49,63		/* r0 = (r3 >> 15) & 1 */

	stb	r4,PACAHARDIRQEN(r13)



	andi.	r0,r3,MSR_PR



	/*

arch/powerpc/kernel/head_64.S

+19 −9
Original line number Diff line number Diff line
@@ -961,10 +961,18 @@ bad_stack: 
 * any task or sent any task a signal, you should use

 * ret_from_except or ret_from_except_lite instead of this.

 */

fast_exc_return_irq:			/* restores irq state too */

	ld	r3,SOFTE(r1)

	ld	r12,_MSR(r1)

	stb	r3,PACASOFTIRQEN(r13)	/* restore paca->soft_enabled */

	rldicl	r4,r12,49,63		/* get MSR_EE to LSB */

	stb	r4,PACAHARDIRQEN(r13)	/* restore paca->hard_enabled */

	b	1f



	.globl	fast_exception_return

fast_exception_return:

	ld	r12,_MSR(r1)

	ld	r11,_NIP(r1)

1:	ld	r11,_NIP(r1)

	andi.	r3,r12,MSR_RI		/* check if RI is set */

	beq-	unrecov_fer
@@ -1361,6 +1369,16 @@ BEGIN_FW_FTR_SECTION 
	 * interrupts if necessary.

	 */

	beq	.ret_from_except_lite

END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)

#endif

BEGIN_FW_FTR_SECTION

	/*

	 * Here we have interrupts hard-disabled, so it is sufficient

	 * to restore paca->{soft,hard}_enable and get out.

	 */

	beq	fast_exc_return_irq	/* Return from exception on success */

END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)



	/* For a hash failure, we don't bother re-enabling interrupts */

	ble-	12f
@@ -1372,14 +1390,6 @@ BEGIN_FW_FTR_SECTION 
	ld	r3,SOFTE(r1)

	bl	.local_irq_restore

	b	11f

END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)

#endif

BEGIN_FW_FTR_SECTION

	beq	fast_exception_return   /* Return from exception on success */

	ble-	12f			/* Failure return from hash_page */



	/* fall through */

END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)



/* Here we have a page fault that hash_page can't handle. */

_GLOBAL(handle_page_fault)