powerpc/64s/exception: Move soft-mask test to common code

As well as moving code out of the unrelocated vectors, this allows the
masked handlers to be moved to common code, and allows the soft_nmi
handler to be generated more like a regular handler.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-12-npiggin@gmail.com

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

@@ -411,36 +411,6 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948)
 	.if (!\virt && IKVM_REAL) || (\virt && IKVM_VIRT)
 		KVMTEST \name IHSRR IVEC
 	.endif
-	.if IMASK
-		lbz	r10,PACAIRQSOFTMASK(r13)
-		andi.	r10,r10,IMASK
-		/* Associate vector numbers with bits in paca->irq_happened */
-		.if IVEC == 0x500 || IVEC == 0xea0
-		li	r10,PACA_IRQ_EE
-		.elseif IVEC == 0x900
-		li	r10,PACA_IRQ_DEC
-		.elseif IVEC == 0xa00 || IVEC == 0xe80
-		li	r10,PACA_IRQ_DBELL
-		.elseif IVEC == 0xe60
-		li	r10,PACA_IRQ_HMI
-		.elseif IVEC == 0xf00
-		li	r10,PACA_IRQ_PMI
-		.else
-		.abort "Bad maskable vector"
-		.endif
-
-		.if IHSRR == EXC_HV_OR_STD
-		BEGIN_FTR_SECTION
-		bne	masked_Hinterrupt
-		FTR_SECTION_ELSE
-		bne	masked_interrupt
-		ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
-		.elseif IHSRR
-		bne	masked_Hinterrupt
-		.else
-		bne	masked_interrupt
-		.endif
-	.endif
 
 	std	r11,IAREA+EX_R11(r13)
 	std	r12,IAREA+EX_R12(r13)
@@ -524,6 +494,37 @@ DEFINE_FIXED_SYMBOL(\name\()_common_virt)
 .endm
 
 .macro __GEN_COMMON_BODY name
+	.if IMASK
+		lbz	r10,PACAIRQSOFTMASK(r13)
+		andi.	r10,r10,IMASK
+		/* Associate vector numbers with bits in paca->irq_happened */
+		.if IVEC == 0x500 || IVEC == 0xea0
+		li	r10,PACA_IRQ_EE
+		.elseif IVEC == 0x900
+		li	r10,PACA_IRQ_DEC
+		.elseif IVEC == 0xa00 || IVEC == 0xe80
+		li	r10,PACA_IRQ_DBELL
+		.elseif IVEC == 0xe60
+		li	r10,PACA_IRQ_HMI
+		.elseif IVEC == 0xf00
+		li	r10,PACA_IRQ_PMI
+		.else
+		.abort "Bad maskable vector"
+		.endif
+
+		.if IHSRR == EXC_HV_OR_STD
+		BEGIN_FTR_SECTION
+		bne	masked_Hinterrupt
+		FTR_SECTION_ELSE
+		bne	masked_interrupt
+		ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
+		.elseif IHSRR
+		bne	masked_Hinterrupt
+		.else
+		bne	masked_interrupt
+		.endif
+	.endif
+
 	.if ISTACK
 	andi.	r10,r12,MSR_PR		/* See if coming from user	*/
 	mr	r10,r1			/* Save r1			*/
@@ -2330,18 +2331,10 @@ EXC_VIRT_NONE(0x5800, 0x100)
 
 #ifdef CONFIG_PPC_WATCHDOG
 
-#define MASKED_DEC_HANDLER_LABEL 3f
-
-#define MASKED_DEC_HANDLER(_H)				\
-3: /* soft-nmi */					\
-	std	r12,PACA_EXGEN+EX_R12(r13);		\
-	GET_SCRATCH0(r10);				\
-	std	r10,PACA_EXGEN+EX_R13(r13);		\
-	mfspr	r11,SPRN_SRR0;		/* save SRR0 */	\
-	mfspr	r12,SPRN_SRR1;		/* and SRR1 */	\
-	LOAD_HANDLER(r10, soft_nmi_common);		\
-	mtctr	r10;					\
-	bctr
+INT_DEFINE_BEGIN(soft_nmi)
+	IVEC=0x900
+	ISTACK=0
+INT_DEFINE_END(soft_nmi)
 
 /*
  * Branch to soft_nmi_interrupt using the emergency stack. The emergency
@@ -2353,19 +2346,16 @@ EXC_VIRT_NONE(0x5800, 0x100)
  * and run it entirely with interrupts hard disabled.
  */
 EXC_COMMON_BEGIN(soft_nmi_common)
+	mfspr	r11,SPRN_SRR0
 	mr	r10,r1
 	ld	r1,PACAEMERGSP(r13)
 	subi	r1,r1,INT_FRAME_SIZE
-	__ISTACK(decrementer)=0
-	__GEN_COMMON_BODY decrementer
+	__GEN_COMMON_BODY soft_nmi
 	bl	save_nvgprs
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	soft_nmi_interrupt
 	b	ret_from_except
 
-#else /* CONFIG_PPC_WATCHDOG */
-#define MASKED_DEC_HANDLER_LABEL 2f /* normal return */
-#define MASKED_DEC_HANDLER(_H)
 #endif /* CONFIG_PPC_WATCHDOG */
 
 /*
@@ -2384,7 +2374,6 @@ masked_Hinterrupt:
 	.else
 masked_interrupt:
 	.endif
-	std	r11,PACA_EXGEN+EX_R11(r13)
 	lbz	r11,PACAIRQHAPPENED(r13)
 	or	r11,r11,r10
 	stb	r11,PACAIRQHAPPENED(r13)
@@ -2393,34 +2382,37 @@ masked_interrupt:
 	lis	r10,0x7fff
 	ori	r10,r10,0xffff
 	mtspr	SPRN_DEC,r10
-	b	MASKED_DEC_HANDLER_LABEL
+#ifdef CONFIG_PPC_WATCHDOG
+	b	soft_nmi_common
+#else
+	b	2f
+#endif
 1:	andi.	r10,r10,PACA_IRQ_MUST_HARD_MASK
 	beq	2f
+	xori	r12,r12,MSR_EE	/* clear MSR_EE */
 	.if \hsrr
-	mfspr	r10,SPRN_HSRR1
-	xori	r10,r10,MSR_EE	/* clear MSR_EE */
-	mtspr	SPRN_HSRR1,r10
+	mtspr	SPRN_HSRR1,r12
 	.else
-	mfspr	r10,SPRN_SRR1
-	xori	r10,r10,MSR_EE	/* clear MSR_EE */
-	mtspr	SPRN_SRR1,r10
+	mtspr	SPRN_SRR1,r12
 	.endif
 	ori	r11,r11,PACA_IRQ_HARD_DIS
 	stb	r11,PACAIRQHAPPENED(r13)
 2:	/* done */
+	ld	r10,PACA_EXGEN+EX_CTR(r13)
+	mtctr	r10
 	mtcrf	0x80,r9
 	std	r1,PACAR1(r13)
 	ld	r9,PACA_EXGEN+EX_R9(r13)
 	ld	r10,PACA_EXGEN+EX_R10(r13)
 	ld	r11,PACA_EXGEN+EX_R11(r13)
+	ld	r12,PACA_EXGEN+EX_R12(r13)
 	/* returns to kernel where r13 must be set up, so don't restore it */
 	.if \hsrr
 	HRFI_TO_KERNEL
 	.else
 	RFI_TO_KERNEL
 	.endif
 	b	.
-	MASKED_DEC_HANDLER(\hsrr\())
 .endm
 
 TRAMP_REAL_BEGIN(stf_barrier_fallback)
@@ -2527,7 +2519,7 @@ TRAMP_REAL_BEGIN(hrfi_flush_fallback)
  * instruction code patches (which end up in the common .text area)
  * cannot reach these if they are put there.
  */
-USE_FIXED_SECTION(virt_trampolines)
+USE_TEXT_SECTION()
 	MASKED_INTERRUPT EXC_STD
 	MASKED_INTERRUPT EXC_HV