From: Nicholas Piggin <npiggin@gmail.com>
Date: Mon, 19 Dec 2016 18:30:02 +0000 (+1000)
Subject: powerpc/64s: Add exception macro that does not enable RI
X-Git-Tag: v4.14-rc1~913^2~38
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=83a980f7f4769c0673f0f966350d1db26993a193;p=platform%2Fkernel%2Flinux-rpi.git

powerpc/64s: Add exception macro that does not enable RI

Subsequent patches will add more non-RI variant exceptions, so
create a macro for it rather than open-code it.

This does not change generated instructions.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 8925981..99ed1d8 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -200,6 +200,21 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 #define EXCEPTION_PROLOG_PSERIES_1(label, h)				\
 	__EXCEPTION_PROLOG_PSERIES_1(label, h)
 
+/* _NORI variant keeps MSR_RI clear */
+#define __EXCEPTION_PROLOG_PSERIES_1_NORI(label, h)			\
+	ld	r10,PACAKMSR(r13);	/* get MSR value for kernel */	\
+	xori	r10,r10,MSR_RI;		/* Clear MSR_RI */		\
+	mfspr	r11,SPRN_##h##SRR0;	/* save SRR0 */			\
+	LOAD_HANDLER(r12,label)						\
+	mtspr	SPRN_##h##SRR0,r12;					\
+	mfspr	r12,SPRN_##h##SRR1;	/* and SRR1 */			\
+	mtspr	SPRN_##h##SRR1,r10;					\
+	h##rfid;							\
+	b	.	/* prevent speculative execution */
+
+#define EXCEPTION_PROLOG_PSERIES_1_NORI(label, h)			\
+	__EXCEPTION_PROLOG_PSERIES_1_NORI(label, h)
+
 #define EXCEPTION_PROLOG_PSERIES(area, label, h, extra, vec)		\
 	EXCEPTION_PROLOG_0(area);					\
 	EXCEPTION_PROLOG_1(area, extra, vec);				\
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 28f8d7b..aa65e3c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -240,20 +240,11 @@ machine_check_fwnmi:
 machine_check_pSeries_0:
 	EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST_PR, 0x200)
 	/*
-	 * The following is essentially EXCEPTION_PROLOG_PSERIES_1 with the
-	 * difference that MSR_RI is not enabled, because PACA_EXMC is being
-	 * used, so nested machine check corrupts it. machine_check_common
-	 * enables MSR_RI.
+	 * MSR_RI is not enabled, because PACA_EXMC is being used, so a
+	 * nested machine check corrupts it. machine_check_common enables
+	 * MSR_RI.
 	 */
-	ld	r10,PACAKMSR(r13)
-	xori	r10,r10,MSR_RI
-	mfspr	r11,SPRN_SRR0
-	LOAD_HANDLER(r12, machine_check_common)
-	mtspr	SPRN_SRR0,r12
-	mfspr	r12,SPRN_SRR1
-	mtspr	SPRN_SRR1,r10
-	rfid
-	b	.	/* prevent speculative execution */
+	EXCEPTION_PROLOG_PSERIES_1_NORI(machine_check_common, EXC_STD)
 
 TRAMP_KVM_SKIP(PACA_EXMC, 0x200)