powerpc/64s: introduce different functions to return from SRR vs HSRR interrupts

This makes no real difference yet except that HSRR type interrupts will
use hrfid to return. This is important for the next patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-4-npiggin@gmail.com

arch/powerpc/kernel/entry_64.S

@@ -635,51 +635,57 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	 * touched, no exit work created, then this can be used.
 	 */
 	.balign IFETCH_ALIGN_BYTES
-	.globl fast_interrupt_return
-fast_interrupt_return:
-_ASM_NOKPROBE_SYMBOL(fast_interrupt_return)
+	.globl fast_interrupt_return_srr
+fast_interrupt_return_srr:
+_ASM_NOKPROBE_SYMBOL(fast_interrupt_return_srr)
 	kuap_check_amr r3, r4
 	ld	r5,_MSR(r1)
 	andi.	r0,r5,MSR_PR
 #ifdef CONFIG_PPC_BOOK3S
-	bne	.Lfast_user_interrupt_return_amr
+	bne	.Lfast_user_interrupt_return_amr_srr
 	kuap_kernel_restore r3, r4
 	andi.	r0,r5,MSR_RI
 	li	r3,0 /* 0 return value, no EMULATE_STACK_STORE */
-	bne+	.Lfast_kernel_interrupt_return
+	bne+	.Lfast_kernel_interrupt_return_srr
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	unrecoverable_exception
 	b	. /* should not get here */
 #else
-	bne	.Lfast_user_interrupt_return
-	b	.Lfast_kernel_interrupt_return
+	bne	.Lfast_user_interrupt_return_srr
+	b	.Lfast_kernel_interrupt_return_srr
 #endif
 
+.macro interrupt_return_macro srr
 	.balign IFETCH_ALIGN_BYTES
-	.globl interrupt_return
-interrupt_return:
-_ASM_NOKPROBE_SYMBOL(interrupt_return)
+	.globl interrupt_return_\srr
+interrupt_return_\srr\():
+_ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
 	ld	r4,_MSR(r1)
 	andi.	r0,r4,MSR_PR
-	beq	.Lkernel_interrupt_return
+	beq	.Lkernel_interrupt_return_\srr
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	interrupt_exit_user_prepare
 	cmpdi	r3,0
-	bne-	.Lrestore_nvgprs
+	bne-	.Lrestore_nvgprs_\srr
 
 #ifdef CONFIG_PPC_BOOK3S
-.Lfast_user_interrupt_return_amr:
+.Lfast_user_interrupt_return_amr_\srr\():
 	kuap_user_restore r3, r4
 #endif
-.Lfast_user_interrupt_return:
+.Lfast_user_interrupt_return_\srr\():
 	ld	r11,_NIP(r1)
 	ld	r12,_MSR(r1)
 BEGIN_FTR_SECTION
 	ld	r10,_PPR(r1)
 	mtspr	SPRN_PPR,r10
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+	.ifc \srr,srr
 	mtspr	SPRN_SRR0,r11
 	mtspr	SPRN_SRR1,r12
+	.else
+	mtspr	SPRN_HSRR0,r11
+	mtspr	SPRN_HSRR1,r12
+	.endif
 
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1		/* to clear the reservation */
@@ -706,24 +712,33 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 	REST_GPR(6, r1)
 	REST_GPR(0, r1)
 	REST_GPR(1, r1)
+	.ifc \srr,srr
 	RFI_TO_USER
+	.else
+	HRFI_TO_USER
+	.endif
 	b	.	/* prevent speculative execution */
 
-.Lrestore_nvgprs:
+.Lrestore_nvgprs_\srr\():
 	REST_NVGPRS(r1)
-	b	.Lfast_user_interrupt_return
+	b	.Lfast_user_interrupt_return_\srr
 
 	.balign IFETCH_ALIGN_BYTES
-.Lkernel_interrupt_return:
+.Lkernel_interrupt_return_\srr\():
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	interrupt_exit_kernel_prepare
 
-.Lfast_kernel_interrupt_return:
+.Lfast_kernel_interrupt_return_\srr\():
 	cmpdi	cr1,r3,0
 	ld	r11,_NIP(r1)
 	ld	r12,_MSR(r1)
+	.ifc \srr,srr
 	mtspr	SPRN_SRR0,r11
 	mtspr	SPRN_SRR1,r12
+	.else
+	mtspr	SPRN_HSRR0,r11
+	mtspr	SPRN_HSRR1,r12
+	.endif
 
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1		/* to clear the reservation */
@@ -757,7 +772,11 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 	REST_GPR(6, r1)
 	REST_GPR(0, r1)
 	REST_GPR(1, r1)
+	.ifc \srr,srr
 	RFI_TO_KERNEL
+	.else
+	HRFI_TO_KERNEL
+	.endif
 	b	.	/* prevent speculative execution */
 
 1:	/*
@@ -777,8 +796,18 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 	std	r9,0(r1) /* perform store component of stdu */
 	ld	r9,PACA_EXGEN+0(r13)
 
+	.ifc \srr,srr
 	RFI_TO_KERNEL
+	.else
+	HRFI_TO_KERNEL
+	.endif
 	b	.	/* prevent speculative execution */
+.endm
+
+interrupt_return_macro srr
+#ifdef CONFIG_PPC_BOOK3S
+interrupt_return_macro hsrr
+#endif
 
 #ifdef CONFIG_PPC_RTAS
 /*

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

@@ -26,6 +26,10 @@
 #include <asm/feature-fixups.h>
 #include <asm/context_tracking.h>
 
+/* 64e interrupt returns always use SRR registers */
+#define fast_interrupt_return fast_interrupt_return_srr
+#define interrupt_return interrupt_return_srr
+
 /* XXX This will ultimately add space for a special exception save
  *     structure used to save things like SRR0/SRR1, SPRGs, MAS, etc...
  *     when taking special interrupts. For now we don't support that,

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

@@ -1149,7 +1149,7 @@ EXC_COMMON_BEGIN(machine_check_common)
 	mtmsrd 	r10,1
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	machine_check_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 #ifdef CONFIG_PPC_P7_NAP
@@ -1275,7 +1275,7 @@ BEGIN_MMU_FTR_SECTION
 MMU_FTR_SECTION_ELSE
 	bl	do_page_fault
 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
-	b	interrupt_return
+	b	interrupt_return_srr
 
 1:	bl	do_break
 	/*
@@ -1283,7 +1283,7 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	 * If so, we need to restore them with their updated values.
 	 */
 	REST_NVGPRS(r1)
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -1323,7 +1323,7 @@ BEGIN_MMU_FTR_SECTION
 	bl	do_slb_fault
 	cmpdi	r3,0
 	bne-	1f
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 1:	/* Error case */
 MMU_FTR_SECTION_ELSE
 	/* Radix case, access is outside page table range */
@@ -1332,7 +1332,7 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	std	r3,RESULT(r1)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	do_bad_slb_fault
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -1368,7 +1368,7 @@ BEGIN_MMU_FTR_SECTION
 MMU_FTR_SECTION_ELSE
 	bl	do_page_fault
 ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -1403,7 +1403,7 @@ BEGIN_MMU_FTR_SECTION
 	bl	do_slb_fault
 	cmpdi	r3,0
 	bne-	1f
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 1:	/* Error case */
 MMU_FTR_SECTION_ELSE
 	/* Radix case, access is outside page table range */
@@ -1412,7 +1412,7 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 	std	r3,RESULT(r1)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	do_bad_slb_fault
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -1456,7 +1456,11 @@ EXC_COMMON_BEGIN(hardware_interrupt_common)
 	GEN_COMMON hardware_interrupt
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	do_IRQ
-	b	interrupt_return
+	BEGIN_FTR_SECTION
+	b	interrupt_return_hsrr
+	FTR_SECTION_ELSE
+	b	interrupt_return_srr
+	ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
 
 
 /**
@@ -1483,7 +1487,7 @@ EXC_COMMON_BEGIN(alignment_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	alignment_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -1590,7 +1594,7 @@ EXC_COMMON_BEGIN(program_check_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	program_check_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /*
@@ -1633,12 +1637,12 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_TM)
 #endif
 	bl	load_up_fpu
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:	/* User process was in a transaction */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	fp_unavailable_tm
-	b	interrupt_return
+	b	interrupt_return_srr
 #endif
 
 
@@ -1677,7 +1681,7 @@ EXC_COMMON_BEGIN(decrementer_common)
 	GEN_COMMON decrementer
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	timer_interrupt
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -1761,7 +1765,7 @@ EXC_COMMON_BEGIN(doorbell_super_common)
 #else
 	bl	unknown_async_exception
 #endif
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 EXC_REAL_NONE(0xb00, 0x100)
@@ -1925,7 +1929,7 @@ EXC_COMMON_BEGIN(single_step_common)
 	GEN_COMMON single_step
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	single_step_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -1963,7 +1967,7 @@ BEGIN_MMU_FTR_SECTION
 MMU_FTR_SECTION_ELSE
 	bl      unknown_exception
 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
-	b       interrupt_return
+	b       interrupt_return_hsrr
 
 
 /**
@@ -1988,7 +1992,7 @@ EXC_COMMON_BEGIN(h_instr_storage_common)
 	GEN_COMMON h_instr_storage
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	unknown_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 
 /**
@@ -2012,7 +2016,7 @@ EXC_COMMON_BEGIN(emulation_assist_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	emulation_assist_interrupt
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 
 /**
@@ -2089,7 +2093,7 @@ EXC_COMMON_BEGIN(hmi_exception_common)
 	GEN_COMMON hmi_exception
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	handle_hmi_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 
 /**
@@ -2119,7 +2123,7 @@ EXC_COMMON_BEGIN(h_doorbell_common)
 #else
 	bl	unknown_async_exception
 #endif
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 
 /**
@@ -2145,7 +2149,7 @@ EXC_COMMON_BEGIN(h_virt_irq_common)
 	GEN_COMMON h_virt_irq
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	do_IRQ
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 
 EXC_REAL_NONE(0xec0, 0x20)
@@ -2188,7 +2192,7 @@ EXC_COMMON_BEGIN(performance_monitor_common)
 	GEN_COMMON performance_monitor
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	performance_monitor_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -2225,19 +2229,19 @@ BEGIN_FTR_SECTION
   END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
 #endif
 	bl	load_up_altivec
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:	/* User process was in a transaction */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	altivec_unavailable_tm
-	b	interrupt_return
+	b	interrupt_return_srr
 #endif
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	altivec_unavailable_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -2278,14 +2282,14 @@ BEGIN_FTR_SECTION
 2:	/* User process was in a transaction */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	vsx_unavailable_tm
-	b	interrupt_return
+	b	interrupt_return_srr
 #endif
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 #endif
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	vsx_unavailable_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -2313,7 +2317,7 @@ EXC_COMMON_BEGIN(facility_unavailable_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	facility_unavailable_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 /**
@@ -2341,7 +2345,7 @@ EXC_COMMON_BEGIN(h_facility_unavailable_common)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	facility_unavailable_exception
 	REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 
 EXC_REAL_NONE(0xfa0, 0x20)
@@ -2370,7 +2374,7 @@ EXC_COMMON_BEGIN(cbe_system_error_common)
 	GEN_COMMON cbe_system_error
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	cbe_system_error_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 #else /* CONFIG_CBE_RAS */
 EXC_REAL_NONE(0x1200, 0x100)
@@ -2401,7 +2405,7 @@ EXC_COMMON_BEGIN(instruction_breakpoint_common)
 	GEN_COMMON instruction_breakpoint
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	instruction_breakpoint_exception
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 EXC_REAL_NONE(0x1400, 0x100)
@@ -2521,7 +2525,7 @@ EXC_COMMON_BEGIN(denorm_exception_common)
 	GEN_COMMON denorm_exception
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	unknown_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 
 #ifdef CONFIG_CBE_RAS
@@ -2538,7 +2542,7 @@ EXC_COMMON_BEGIN(cbe_maintenance_common)
 	GEN_COMMON cbe_maintenance
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	cbe_maintenance_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 #else /* CONFIG_CBE_RAS */
 EXC_REAL_NONE(0x1600, 0x100)
@@ -2568,7 +2572,7 @@ EXC_COMMON_BEGIN(altivec_assist_common)
 #else
 	bl	unknown_exception
 #endif
-	b	interrupt_return
+	b	interrupt_return_srr
 
 
 #ifdef CONFIG_CBE_RAS
@@ -2585,7 +2589,7 @@ EXC_COMMON_BEGIN(cbe_thermal_common)
 	GEN_COMMON cbe_thermal
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	cbe_thermal_exception
-	b	interrupt_return
+	b	interrupt_return_hsrr
 
 #else /* CONFIG_CBE_RAS */
 EXC_REAL_NONE(0x1800, 0x100)

arch/powerpc/kernel/vector.S

@@ -131,7 +131,7 @@ _GLOBAL(load_up_vsx)
 	/* enable use of VSX after return */
 	oris	r12,r12,MSR_VSX@h
 	std	r12,_MSR(r1)
-	b	fast_interrupt_return
+	b	fast_interrupt_return_srr
 
 #endif /* CONFIG_VSX */