Commit 16754d25 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/64s/exceptions: Change irq reconcile for NMIs from reusing _DAR to RESULT 



A spare interrupt stack slot is needed to save irq state when
reconciling NMIs (sreset and decrementer soft-nmi). _DAR is used
for this, but we want to reconcile machine checks as well, which
do use _DAR. Switch to using RESULT instead, as it's used by
system calls.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200508043408.886394-4-npiggin@gmail.com
parent ac2a2a14

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

+5 −5
Original line number Diff line number Diff line
@@ -939,13 +939,13 @@ EXC_COMMON_BEGIN(system_reset_common) 
	 * the right thing. We do not want to reconcile because that goes

	 * through irq tracing which we don't want in NMI.

	 *

	 * Save PACAIRQHAPPENED to _DAR (otherwise unused), and set HARD_DIS

	 * Save PACAIRQHAPPENED to RESULT (otherwise unused), and set HARD_DIS

	 * as we are running with MSR[EE]=0.

	 */

	li	r10,IRQS_ALL_DISABLED

	stb	r10,PACAIRQSOFTMASK(r13)

	lbz	r10,PACAIRQHAPPENED(r13)

	std	r10,_DAR(r1)

	std	r10,RESULT(r1)

	ori	r10,r10,PACA_IRQ_HARD_DIS

	stb	r10,PACAIRQHAPPENED(r13)
@@ -966,7 +966,7 @@ EXC_COMMON_BEGIN(system_reset_common) 
	/*

	 * Restore soft mask settings.

	 */

	ld	r10,_DAR(r1)

	ld	r10,RESULT(r1)

	stb	r10,PACAIRQHAPPENED(r13)

	ld	r10,SOFTE(r1)

	stb	r10,PACAIRQSOFTMASK(r13)
@@ -2743,7 +2743,7 @@ EXC_COMMON_BEGIN(soft_nmi_common) 
	li	r10,IRQS_ALL_DISABLED

	stb	r10,PACAIRQSOFTMASK(r13)

	lbz	r10,PACAIRQHAPPENED(r13)

	std	r10,_DAR(r1)

	std	r10,RESULT(r1)

	ori	r10,r10,PACA_IRQ_HARD_DIS

	stb	r10,PACAIRQHAPPENED(r13)
@@ -2757,7 +2757,7 @@ EXC_COMMON_BEGIN(soft_nmi_common) 
	/*

	 * Restore soft mask settings.

	 */

	ld	r10,_DAR(r1)

	ld	r10,RESULT(r1)

	stb	r10,PACAIRQHAPPENED(r13)

	ld	r10,SOFTE(r1)

	stb	r10,PACAIRQSOFTMASK(r13)

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