From: Nicholas Piggin <npiggin@gmail.com>
Date: Mon, 1 May 2017 12:01:09 +0000 (+1000)
Subject: powerpc/64s: Fix FIXUP_ENDIAN non-maskable interrupt reentrancy
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f1fe5252018075e18d7f0c0e23ee173546420361;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

powerpc/64s: Fix FIXUP_ENDIAN non-maskable interrupt reentrancy

FIXUP_ENDIAN uses SRR[01] with MSR_RI=1, which gets corrupted if there
is an interleaving system reset or machine check interrupt.

Set MSR_RI=0 before setting SRRs. The rfid will restore MSR.

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

diff --git a/arch/powerpc/boot/ppc_asm.h b/arch/powerpc/boot/ppc_asm.h
index b03373d8b386..68e388ee94fe 100644
--- a/arch/powerpc/boot/ppc_asm.h
+++ b/arch/powerpc/boot/ppc_asm.h
@@ -67,13 +67,15 @@
 #define MSR_LE		0x0000000000000001
 
 #define FIXUP_ENDIAN						   \
-	tdi   0, 0, 0x48; /* Reverse endian of b . + 8		*/ \
-	b     $+36;	  /* Skip trampoline if endian is good	*/ \
-	.long 0x05009f42; /* bcl 20,31,$+4			*/ \
-	.long 0xa602487d; /* mflr r10				*/ \
-	.long 0x1c004a39; /* addi r10,r10,28			*/ \
+	tdi   0,0,0x48;	  /* Reverse endian of b . + 8		*/ \
+	b     $+44;	  /* Skip trampoline if endian is good	*/ \
 	.long 0xa600607d; /* mfmsr r11				*/ \
 	.long 0x01006b69; /* xori r11,r11,1			*/ \
+	.long 0x00004039; /* li r10,0				*/ \
+	.long 0x6401417d; /* mtmsrd r10,1			*/ \
+	.long 0x05009f42; /* bcl 20,31,$+4			*/ \
+	.long 0xa602487d; /* mflr r10				*/ \
+	.long 0x14004a39; /* addi r10,r10,20			*/ \
 	.long 0xa6035a7d; /* mtsrr0 r10				*/ \
 	.long 0xa6037b7d; /* mtsrr1 r11				*/ \
 	.long 0x2400004c  /* rfid				*/
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 359c44341761..6baeeb9acd0d 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -770,15 +770,18 @@ END_FTR_SECTION_IFCLR(CPU_FTR_601)
 #else
 #define FIXUP_ENDIAN						   \
 	tdi   0,0,0x48;	  /* Reverse endian of b . + 8		*/ \
-	b     $+36;	  /* Skip trampoline if endian is good	*/ \
-	.long 0x05009f42; /* bcl 20,31,$+4			*/ \
-	.long 0xa602487d; /* mflr r10				*/ \
-	.long 0x1c004a39; /* addi r10,r10,28			*/ \
+	b     $+44;	  /* Skip trampoline if endian is good	*/ \
 	.long 0xa600607d; /* mfmsr r11				*/ \
 	.long 0x01006b69; /* xori r11,r11,1			*/ \
+	.long 0x00004039; /* li r10,0				*/ \
+	.long 0x6401417d; /* mtmsrd r10,1			*/ \
+	.long 0x05009f42; /* bcl 20,31,$+4			*/ \
+	.long 0xa602487d; /* mflr r10				*/ \
+	.long 0x14004a39; /* addi r10,r10,20			*/ \
 	.long 0xa6035a7d; /* mtsrr0 r10				*/ \
 	.long 0xa6037b7d; /* mtsrr1 r11				*/ \
 	.long 0x2400004c  /* rfid				*/
+
 #endif /* !CONFIG_PPC_BOOK3E */
 
 #endif /*  __ASSEMBLY__ */