* [PATCH v2 01/11] powerpc: remove interrupt exit helpers unused argument
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 17:46 ` Christophe Leroy
2021-05-21 11:44 ` [PATCH v2 02/11] powerpc/64s: introduce different functions to return from SRR vs HSRR interrupts Nicholas Piggin
` (9 subsequent siblings)
10 siblings, 1 reply; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
The msr argument is not used, remove it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/asm-prototypes.h | 4 ++--
arch/powerpc/kernel/interrupt.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 1c7b75834e04..95492655462e 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -71,8 +71,8 @@ void __init machine_init(u64 dt_ptr);
#endif
long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8, unsigned long r0, struct pt_regs *regs);
notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *regs, long scv);
-notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr);
-notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsigned long msr);
+notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs);
+notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs);
long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
u32 len_high, u32 len_low);
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index e0938ba298f2..38ae7057d6c2 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -352,7 +352,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
return ret;
}
-notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr)
+notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs)
{
unsigned long ti_flags;
unsigned long flags;
@@ -431,7 +431,7 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
void preempt_schedule_irq(void);
-notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsigned long msr)
+notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs)
{
unsigned long flags;
unsigned long ret = 0;
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [PATCH v2 01/11] powerpc: remove interrupt exit helpers unused argument
2021-05-21 11:44 ` [PATCH v2 01/11] powerpc: remove interrupt exit helpers unused argument Nicholas Piggin
@ 2021-05-21 17:46 ` Christophe Leroy
0 siblings, 0 replies; 13+ messages in thread
From: Christophe Leroy @ 2021-05-21 17:46 UTC (permalink / raw)
To: Nicholas Piggin; +Cc: linuxppc-dev
Nicholas Piggin <npiggin@gmail.com> a écrit :
> The msr argument is not used, remove it.
Why not keep and use that msr argument instead of re-reading regs->msr ?
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> arch/powerpc/include/asm/asm-prototypes.h | 4 ++--
> arch/powerpc/kernel/interrupt.c | 4 ++--
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/asm-prototypes.h
> b/arch/powerpc/include/asm/asm-prototypes.h
> index 1c7b75834e04..95492655462e 100644
> --- a/arch/powerpc/include/asm/asm-prototypes.h
> +++ b/arch/powerpc/include/asm/asm-prototypes.h
> @@ -71,8 +71,8 @@ void __init machine_init(u64 dt_ptr);
> #endif
> long system_call_exception(long r3, long r4, long r5, long r6, long
> r7, long r8, unsigned long r0, struct pt_regs *regs);
> notrace unsigned long syscall_exit_prepare(unsigned long r3, struct
> pt_regs *regs, long scv);
> -notrace unsigned long interrupt_exit_user_prepare(struct pt_regs
> *regs, unsigned long msr);
> -notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs
> *regs, unsigned long msr);
> +notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs);
> +notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs);
>
> long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
> u32 len_high, u32 len_low);
> diff --git a/arch/powerpc/kernel/interrupt.c
> b/arch/powerpc/kernel/interrupt.c
> index e0938ba298f2..38ae7057d6c2 100644
> --- a/arch/powerpc/kernel/interrupt.c
> +++ b/arch/powerpc/kernel/interrupt.c
> @@ -352,7 +352,7 @@ notrace unsigned long
> syscall_exit_prepare(unsigned long r3,
> return ret;
> }
>
> -notrace unsigned long interrupt_exit_user_prepare(struct pt_regs
> *regs, unsigned long msr)
> +notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs)
> {
> unsigned long ti_flags;
> unsigned long flags;
> @@ -431,7 +431,7 @@ notrace unsigned long
> interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
>
> void preempt_schedule_irq(void);
>
> -notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs
> *regs, unsigned long msr)
> +notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs)
> {
> unsigned long flags;
> unsigned long ret = 0;
> --
> 2.23.0
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v2 02/11] powerpc/64s: introduce different functions to return from SRR vs HSRR interrupts
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 01/11] powerpc: remove interrupt exit helpers unused argument Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 03/11] powerpc/64s: avoid reloading (H)SRR registers if they are still valid Nicholas Piggin
` (8 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
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>
---
arch/powerpc/kernel/entry_64.S | 65 +++++++++++++++++-------
arch/powerpc/kernel/exceptions-64e.S | 4 ++
arch/powerpc/kernel/exceptions-64s.S | 76 +++++++++++++++-------------
arch/powerpc/kernel/vector.S | 2 +-
4 files changed, 92 insertions(+), 55 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 03727308d8cc..03a45a88b4b8 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/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
/*
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index f1ae710274bc..b35c97c7082f 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/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,
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index fa8e52a0239e..3a63feedae0b 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1234,7 +1234,7 @@ 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
GEN_KVM machine_check
@@ -1363,7 +1363,7 @@ 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
/*
@@ -1371,7 +1371,7 @@ 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
GEN_KVM data_access
@@ -1414,7 +1414,7 @@ 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 */
@@ -1423,7 +1423,7 @@ 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
GEN_KVM data_access_slb
@@ -1461,7 +1461,7 @@ 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
GEN_KVM instruction_access
@@ -1498,7 +1498,7 @@ 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 */
@@ -1507,7 +1507,7 @@ 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
GEN_KVM instruction_access_slb
@@ -1553,7 +1553,11 @@ 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)
GEN_KVM hardware_interrupt
@@ -1582,7 +1586,7 @@ 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
GEN_KVM alignment
@@ -1691,7 +1695,7 @@ 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
GEN_KVM program_check
@@ -1736,12 +1740,12 @@ 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
GEN_KVM fp_unavailable
@@ -1782,7 +1786,7 @@ EXC_COMMON_BEGIN(decrementer_common)
GEN_COMMON decrementer
addi r3,r1,STACK_FRAME_OVERHEAD
bl timer_interrupt
- b interrupt_return
+ b interrupt_return_srr
GEN_KVM decrementer
@@ -1870,7 +1874,7 @@ EXC_COMMON_BEGIN(doorbell_super_common)
#else
bl unknown_async_exception
#endif
- b interrupt_return
+ b interrupt_return_srr
GEN_KVM doorbell_super
@@ -2041,7 +2045,7 @@ 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
GEN_KVM single_step
@@ -2082,7 +2086,7 @@ 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
GEN_KVM h_data_storage
@@ -2109,7 +2113,7 @@ 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
GEN_KVM h_instr_storage
@@ -2135,7 +2139,7 @@ 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
GEN_KVM emulation_assist
@@ -2216,7 +2220,7 @@ 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
GEN_KVM hmi_exception
@@ -2248,7 +2252,7 @@ EXC_COMMON_BEGIN(h_doorbell_common)
#else
bl unknown_async_exception
#endif
- b interrupt_return
+ b interrupt_return_hsrr
GEN_KVM h_doorbell
@@ -2276,7 +2280,7 @@ 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
GEN_KVM h_virt_irq
@@ -2321,7 +2325,7 @@ 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
GEN_KVM performance_monitor
@@ -2360,19 +2364,19 @@ 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
GEN_KVM altivec_unavailable
@@ -2415,14 +2419,14 @@ 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
GEN_KVM vsx_unavailable
@@ -2452,7 +2456,7 @@ 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
GEN_KVM facility_unavailable
@@ -2482,7 +2486,7 @@ 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
GEN_KVM h_facility_unavailable
@@ -2513,7 +2517,7 @@ 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
GEN_KVM cbe_system_error
@@ -2546,7 +2550,7 @@ 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
GEN_KVM instruction_breakpoint
@@ -2668,7 +2672,7 @@ 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
GEN_KVM denorm_exception
@@ -2687,7 +2691,7 @@ 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
GEN_KVM cbe_maintenance
@@ -2719,7 +2723,7 @@ EXC_COMMON_BEGIN(altivec_assist_common)
#else
bl unknown_exception
#endif
- b interrupt_return
+ b interrupt_return_srr
GEN_KVM altivec_assist
@@ -2738,7 +2742,7 @@ 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
GEN_KVM cbe_thermal
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index f5a52f444e36..54dbefcb4cde 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/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 */
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 03/11] powerpc/64s: avoid reloading (H)SRR registers if they are still valid
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 01/11] powerpc: remove interrupt exit helpers unused argument Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 02/11] powerpc/64s: introduce different functions to return from SRR vs HSRR interrupts Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 04/11] powerpc/64: handle MSR EE and RI in interrupt entry wrapper Nicholas Piggin
` (7 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime, or the return
address or MSR are modified, there is no need to reload these registers
when returning from interrupt.
Introduce per-CPU flags that track the validity of SRR and HSRR
registers. These are cleared when returning from interrupt, when
using the registers for something else (e.g., OPAL calls), when
adjusting the return address or MSR of a context, and when context
switching (which changes the return address and MSR).
This improves the performance of interrupt returns.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/Kconfig.debug | 5 ++
arch/powerpc/include/asm/hw_irq.h | 10 ++-
arch/powerpc/include/asm/interrupt.h | 12 +++
arch/powerpc/include/asm/paca.h | 4 +
arch/powerpc/include/asm/ptrace.h | 74 ++++++++++++-----
arch/powerpc/kernel/asm-offsets.c | 4 +
arch/powerpc/kernel/entry_64.S | 92 ++++++++++++++++++++--
arch/powerpc/kernel/exceptions-64s.S | 27 +++++++
arch/powerpc/kernel/fpu.S | 2 +
arch/powerpc/kernel/kgdb.c | 2 +-
arch/powerpc/kernel/kprobes-ftrace.c | 2 +-
arch/powerpc/kernel/kprobes.c | 10 +--
arch/powerpc/kernel/process.c | 26 +++---
arch/powerpc/kernel/rtas.c | 14 +++-
arch/powerpc/kernel/signal.c | 2 +-
arch/powerpc/kernel/signal_64.c | 9 +++
arch/powerpc/kernel/syscalls.c | 3 +-
arch/powerpc/kernel/traps.c | 18 ++---
arch/powerpc/kernel/vector.S | 4 +
arch/powerpc/kvm/book3s_hv.c | 3 +
arch/powerpc/kvm/book3s_pr.c | 1 +
arch/powerpc/lib/sstep.c | 4 +-
arch/powerpc/math-emu/math.c | 2 +-
arch/powerpc/platforms/powernv/opal-call.c | 4 +
arch/powerpc/sysdev/fsl_pci.c | 2 +-
25 files changed, 273 insertions(+), 63 deletions(-)
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 6342f9da4545..205cd77f321f 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -84,6 +84,11 @@ config MSI_BITMAP_SELFTEST
config PPC_IRQ_SOFT_MASK_DEBUG
bool "Include extra checks for powerpc irq soft masking"
+ depends on PPC64
+
+config PPC_RFI_SRR_DEBUG
+ bool "Include extra checks for RFI SRR register validity"
+ depends on PPC_BOOK3S_64
config XMON
bool "Include xmon kernel debugger"
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 56a98936a6a9..19bcef666cf6 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -389,7 +389,15 @@ static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
return !(regs->msr & MSR_EE);
}
-static inline void may_hard_irq_enable(void) { }
+static inline bool may_hard_irq_enable(void)
+{
+ return false;
+}
+
+static inline void do_hard_irq_enable(void)
+{
+ BUILD_BUG();
+}
static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
{
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 59f704408d65..6e9d18838d56 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -73,6 +73,18 @@
#include <asm/kprobes.h>
#include <asm/runlatch.h>
+#ifdef CONFIG_PPC_BOOK3S_64
+static inline void srr_regs_clobbered(void)
+{
+ local_paca->srr_valid = 0;
+ local_paca->hsrr_valid = 0;
+}
+#else
+static inline void srr_regs_clobbered(void)
+{
+}
+#endif
+
static inline void nap_adjust_return(struct pt_regs *regs)
{
#ifdef CONFIG_PPC_970_NAP
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index ec18ac818e3a..dfc984b0e640 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -169,6 +169,10 @@ struct paca_struct {
u64 saved_msr; /* MSR saved here by enter_rtas */
#ifdef CONFIG_PPC_BOOK3E
u16 trap_save; /* Used when bad stack is encountered */
+#endif
+#ifdef CONFIG_PPC_BOOK3S_64
+ u8 hsrr_valid; /* HSRRs set for HRFID */
+ u8 srr_valid; /* SRRs set for RFID */
#endif
u8 irq_soft_mask; /* mask for irq soft masking */
u8 irq_happened; /* irq happened while soft-disabled */
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 9c9ab2746168..516117bba4e6 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -121,27 +121,7 @@ struct pt_regs
#endif /* __powerpc64__ */
#ifndef __ASSEMBLY__
-
-static inline unsigned long instruction_pointer(struct pt_regs *regs)
-{
- return regs->nip;
-}
-
-static inline void instruction_pointer_set(struct pt_regs *regs,
- unsigned long val)
-{
- regs->nip = val;
-}
-
-static inline unsigned long user_stack_pointer(struct pt_regs *regs)
-{
- return regs->gpr[1];
-}
-
-static inline unsigned long frame_pointer(struct pt_regs *regs)
-{
- return 0;
-}
+#include <asm/paca.h>
#ifdef CONFIG_SMP
extern unsigned long profile_pc(struct pt_regs *regs);
@@ -171,6 +151,58 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
regs->gpr[3] = rc;
}
+static inline void regs_set_return_ip(struct pt_regs *regs, unsigned long ip)
+{
+ regs->nip = ip;
+#ifdef CONFIG_PPC_BOOK3S_64
+ local_paca->hsrr_valid = 0;
+ local_paca->srr_valid = 0;
+#endif
+}
+
+static inline void regs_set_return_msr(struct pt_regs *regs, unsigned long msr)
+{
+ regs->msr = msr;
+#ifdef CONFIG_PPC_BOOK3S_64
+ local_paca->hsrr_valid = 0;
+ local_paca->srr_valid = 0;
+#endif
+}
+
+static inline void return_ip_or_msr_changed(void)
+{
+#ifdef CONFIG_PPC_BOOK3S_64
+ local_paca->hsrr_valid = 0;
+ local_paca->srr_valid = 0;
+#endif
+}
+
+static inline void regs_add_return_ip(struct pt_regs *regs, long offset)
+{
+ regs_set_return_ip(regs, regs->nip + offset);
+}
+
+static inline unsigned long instruction_pointer(struct pt_regs *regs)
+{
+ return regs->nip;
+}
+
+static inline void instruction_pointer_set(struct pt_regs *regs,
+ unsigned long val)
+{
+ regs_set_return_ip(regs, val);
+}
+
+static inline unsigned long user_stack_pointer(struct pt_regs *regs)
+{
+ return regs->gpr[1];
+}
+
+static inline unsigned long frame_pointer(struct pt_regs *regs)
+{
+ return 0;
+}
+
#ifdef __powerpc64__
#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
#else
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 28af4efb4587..1c2b869d9d52 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -209,6 +209,10 @@ int main(void)
OFFSET(PACATOC, paca_struct, kernel_toc);
OFFSET(PACAKBASE, paca_struct, kernelbase);
OFFSET(PACAKMSR, paca_struct, kernel_msr);
+#ifdef CONFIG_PPC_BOOK3S
+ OFFSET(PACAHSRR_VALID, paca_struct, hsrr_valid);
+ OFFSET(PACASRR_VALID, paca_struct, srr_valid);
+#endif
OFFSET(PACAIRQSOFTMASK, paca_struct, irq_soft_mask);
OFFSET(PACAIRQHAPPENED, paca_struct, irq_happened);
OFFSET(PACA_FTRACE_ENABLED, paca_struct, ftrace_enabled);
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 03a45a88b4b8..9a1d5e5599d3 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -64,6 +64,30 @@ exception_marker:
.section ".text"
.align 7
+.macro DEBUG_SRR_VALID srr
+#ifdef CONFIG_PPC_RFI_SRR_DEBUG
+ .ifc \srr,srr
+ mfspr r11,SPRN_SRR0
+ ld r12,_NIP(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ mfspr r11,SPRN_SRR1
+ ld r12,_MSR(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ .else
+ mfspr r11,SPRN_HSRR0
+ ld r12,_NIP(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ mfspr r11,SPRN_HSRR1
+ ld r12,_MSR(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ .endif
+#endif
+.endm
+
#ifdef CONFIG_PPC_BOOK3S
.macro system_call_vectored name trapnr
.globl system_call_vectored_\name
@@ -286,6 +310,11 @@ END_BTB_FLUSH_SECTION
ld r11,exception_marker@toc(r2)
std r11,-16(r10) /* "regshere" marker */
+#ifdef CONFIG_PPC_BOOK3S
+ li r11,1
+ stb r11,PACASRR_VALID(r13)
+#endif
+
/*
* We always enter kernel from userspace with irq soft-mask enabled and
* nothing pending. system_call_exception() will call
@@ -306,18 +335,27 @@ END_BTB_FLUSH_SECTION
bl syscall_exit_prepare
ld r2,_CCR(r1)
+ ld r6,_LINK(r1)
+ mtlr r6
+
+#ifdef CONFIG_PPC_BOOK3S
+ lbz r4,PACASRR_VALID(r13)
+ cmpdi r4,0
+ bne 1f
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+#endif
ld r4,_NIP(r1)
ld r5,_MSR(r1)
- ld r6,_LINK(r1)
+ mtspr SPRN_SRR0,r4
+ mtspr SPRN_SRR1,r5
+1:
+ DEBUG_SRR_VALID srr
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
- mtspr SPRN_SRR0,r4
- mtspr SPRN_SRR1,r5
- mtlr r6
-
cmpdi r3,0
bne .Lsyscall_restore_regs
/* Zero volatile regs that may contain sensitive kernel data */
@@ -673,19 +711,40 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
kuap_user_restore r3, r4
#endif
.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)
+
+#ifdef CONFIG_PPC_BOOK3S
+ .ifc \srr,srr
+ lbz r4,PACASRR_VALID(r13)
+ .else
+ lbz r4,PACAHSRR_VALID(r13)
+ .endif
+ cmpdi r4,0
+ li r4,0
+ bne 1f
+#endif
+ ld r11,_NIP(r1)
+ ld r12,_MSR(r1)
.ifc \srr,srr
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACASRR_VALID(r13)
+#endif
.else
mtspr SPRN_HSRR0,r11
mtspr SPRN_HSRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACAHSRR_VALID(r13)
+#endif
.endif
+ DEBUG_SRR_VALID \srr
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
@@ -730,15 +789,34 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
.Lfast_kernel_interrupt_return_\srr\():
cmpdi cr1,r3,0
+#ifdef CONFIG_PPC_BOOK3S
+ .ifc \srr,srr
+ lbz r4,PACASRR_VALID(r13)
+ .else
+ lbz r4,PACAHSRR_VALID(r13)
+ .endif
+ cmpdi r4,0
+ li r4,0
+ bne 1f
+#endif
ld r11,_NIP(r1)
ld r12,_MSR(r1)
.ifc \srr,srr
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACASRR_VALID(r13)
+#endif
.else
mtspr SPRN_HSRR0,r11
mtspr SPRN_HSRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACAHSRR_VALID(r13)
+#endif
.endif
+ DEBUG_SRR_VALID \srr
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 3a63feedae0b..5c18a2a3058d 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -567,6 +567,20 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
std r0,GPR0(r1) /* save r0 in stackframe */
std r10,GPR1(r1) /* save r1 in stackframe */
+ /* Mark our [H]SRRs valid for return */
+ li r10,1
+ .if IHSRR_IF_HVMODE
+ BEGIN_FTR_SECTION
+ stb r10,PACAHSRR_VALID(r13)
+ FTR_SECTION_ELSE
+ stb r10,PACASRR_VALID(r13)
+ ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
+ .elseif IHSRR
+ stb r10,PACAHSRR_VALID(r13)
+ .else
+ stb r10,PACASRR_VALID(r13)
+ .endif
+
.if ISET_RI
li r10,MSR_RI
mtmsrd r10,1 /* Set MSR_RI */
@@ -666,10 +680,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
.macro EXCEPTION_RESTORE_REGS hsrr=0
/* Move original SRR0 and SRR1 into the respective regs */
ld r9,_MSR(r1)
+ li r10,0
.if \hsrr
mtspr SPRN_HSRR1,r9
+ stb r10,PACAHSRR_VALID(r13)
.else
mtspr SPRN_SRR1,r9
+ stb r10,PACASRR_VALID(r13)
.endif
ld r9,_NIP(r1)
.if \hsrr
@@ -1825,6 +1842,8 @@ EXC_COMMON_BEGIN(hdecrementer_common)
*
* Be careful to avoid touching the kernel stack.
*/
+ li r10,0
+ stb r10,PACAHSRR_VALID(r13)
ld r10,PACA_EXGEN+EX_CTR(r13)
mtctr r10
mtcrf 0x80,r9
@@ -2660,6 +2679,8 @@ BEGIN_FTR_SECTION
ld r10,PACA_EXGEN+EX_CFAR(r13)
mtspr SPRN_CFAR,r10
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+ li r10,0
+ stb r10,PACAHSRR_VALID(r13)
ld r10,PACA_EXGEN+EX_R10(r13)
ld r11,PACA_EXGEN+EX_R11(r13)
ld r12,PACA_EXGEN+EX_R12(r13)
@@ -2828,6 +2849,12 @@ masked_interrupt:
ori r11,r11,PACA_IRQ_HARD_DIS
stb r11,PACAIRQHAPPENED(r13)
2: /* done */
+ li r10,0
+ .if \hsrr
+ stb r10,PACAHSRR_VALID(r13)
+ .else
+ stb r10,PACASRR_VALID(r13)
+ .endif
ld r10,PACA_EXGEN+EX_CTR(r13)
mtctr r10
mtcrf 0x80,r9
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 2c57ece6671c..44526c157bff 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -103,6 +103,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
ori r12,r12,MSR_FP
or r12,r12,r4
std r12,_MSR(r1)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
#endif
li r4,1
stb r4,THREAD_LOAD_FP(r5)
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index 7dd2ad3603ad..26163497d69e 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -147,7 +147,7 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs)
return 0;
if (*(u32 *)regs->nip == BREAK_INSTR)
- regs->nip += BREAK_INSTR_SIZE;
+ regs_add_return_ip(regs, BREAK_INSTR_SIZE);
return 1;
}
diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c
index 660138f6c4b2..a4965a32628a 100644
--- a/arch/powerpc/kernel/kprobes-ftrace.c
+++ b/arch/powerpc/kernel/kprobes-ftrace.c
@@ -48,7 +48,7 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip,
* Emulate singlestep (and also recover regs->nip)
* as if there is a nop
*/
- regs->nip += MCOUNT_INSN_SIZE;
+ regs_add_return_ip(regs, MCOUNT_INSN_SIZE);
if (unlikely(p->post_handler)) {
kcb->kprobe_status = KPROBE_HIT_SSDONE;
p->post_handler(p, regs, 0);
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 01ab2163659e..8165ed71ab51 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -178,7 +178,7 @@ static nokprobe_inline void prepare_singlestep(struct kprobe *p, struct pt_regs
* variant as values in regs could play a part in
* if the trap is taken or not
*/
- regs->nip = (unsigned long)p->ainsn.insn;
+ regs_set_return_ip(regs, (unsigned long)p->ainsn.insn);
}
static nokprobe_inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
@@ -415,7 +415,7 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
* we end up emulating it in kprobe_handler(), which increments the nip
* again.
*/
- regs->nip = orig_ret_address - 4;
+ regs_set_return_ip(regs, orig_ret_address - 4);
regs->link = orig_ret_address;
return 0;
@@ -450,7 +450,7 @@ int kprobe_post_handler(struct pt_regs *regs)
}
/* Adjust nip to after the single-stepped instruction */
- regs->nip = (unsigned long)cur->addr + len;
+ regs_set_return_ip(regs, (unsigned long)cur->addr + len);
regs->msr |= kcb->kprobe_saved_msr;
/*Restore back the original saved kprobes variables and continue. */
@@ -490,7 +490,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* and allow the page fault handler to continue as a
* normal page fault.
*/
- regs->nip = (unsigned long)cur->addr;
+ regs_set_return_ip(regs, (unsigned long)cur->addr);
regs->msr &= ~MSR_SINGLESTEP; /* Turn off 'trace' bits */
regs->msr |= kcb->kprobe_saved_msr;
if (kcb->kprobe_status == KPROBE_REENTER)
@@ -523,7 +523,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* zero, try to fix up.
*/
if ((entry = search_exception_tables(regs->nip)) != NULL) {
- regs->nip = extable_fixup(entry);
+ regs_set_return_ip(regs, extable_fixup(entry));
return 1;
}
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 89e34aa273e2..fea5c68daeef 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -96,7 +96,8 @@ static void check_if_tm_restore_required(struct task_struct *tsk)
if (tsk == current && tsk->thread.regs &&
MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
!test_thread_flag(TIF_RESTORE_TM)) {
- tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
+ regs_set_return_msr(&tsk->thread.ckpt_regs,
+ tsk->thread.regs->msr);
set_thread_flag(TIF_RESTORE_TM);
}
}
@@ -161,7 +162,7 @@ static void __giveup_fpu(struct task_struct *tsk)
msr &= ~(MSR_FP|MSR_FE0|MSR_FE1);
if (cpu_has_feature(CPU_FTR_VSX))
msr &= ~MSR_VSX;
- tsk->thread.regs->msr = msr;
+ regs_set_return_msr(tsk->thread.regs, msr);
}
void giveup_fpu(struct task_struct *tsk)
@@ -244,7 +245,7 @@ static void __giveup_altivec(struct task_struct *tsk)
msr &= ~MSR_VEC;
if (cpu_has_feature(CPU_FTR_VSX))
msr &= ~MSR_VSX;
- tsk->thread.regs->msr = msr;
+ regs_set_return_msr(tsk->thread.regs, msr);
}
void giveup_altivec(struct task_struct *tsk)
@@ -559,7 +560,7 @@ void notrace restore_math(struct pt_regs *regs)
msr_check_and_clear(new_msr);
- regs->msr |= new_msr | fpexc_mode;
+ regs_set_return_msr(regs, regs->msr | new_msr | fpexc_mode);
}
}
#endif /* CONFIG_PPC_BOOK3S_64 */
@@ -1287,6 +1288,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
}
#endif /* CONFIG_PPC_BOOK3S_64 */
+ return_ip_or_msr_changed();
+
return last;
}
@@ -1845,6 +1848,9 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
regs->gpr[2] = 0;
regs->msr = MSR_USER32;
}
+
+ return_ip_or_msr_changed();
+
#endif
#ifdef CONFIG_VSX
current->thread.used_vsr = 0;
@@ -1875,7 +1881,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
current->thread.tm_tfiar = 0;
current->thread.load_tm = 0;
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
-
}
EXPORT_SYMBOL(start_thread);
@@ -1923,9 +1928,10 @@ int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
if (val > PR_FP_EXC_PRECISE)
return -EINVAL;
tsk->thread.fpexc_mode = __pack_fe01(val);
- if (regs != NULL && (regs->msr & MSR_FP) != 0)
- regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
- | tsk->thread.fpexc_mode;
+ if (regs != NULL && (regs->msr & MSR_FP) != 0) {
+ regs_set_return_msr(regs, (regs->msr & ~(MSR_FE0|MSR_FE1))
+ | tsk->thread.fpexc_mode);
+ }
return 0;
}
@@ -1971,9 +1977,9 @@ int set_endian(struct task_struct *tsk, unsigned int val)
return -EINVAL;
if (val == PR_ENDIAN_BIG)
- regs->msr &= ~MSR_LE;
+ regs_set_return_msr(regs, regs->msr & ~MSR_LE);
else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
- regs->msr |= MSR_LE;
+ regs_set_return_msr(regs, regs->msr | MSR_LE);
else
return -EINVAL;
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 6bada744402b..99f2cce635fb 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -25,6 +25,7 @@
#include <linux/reboot.h>
#include <linux/syscalls.h>
+#include <asm/interrupt.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/hvcall.h>
@@ -46,6 +47,13 @@
/* This is here deliberately so it's only used in this file */
void enter_rtas(unsigned long);
+static inline void do_enter_rtas(unsigned long args)
+{
+ enter_rtas(args);
+
+ srr_regs_clobbered(); /* rtas uses SRRs, invalidate */
+}
+
struct rtas_t rtas = {
.lock = __ARCH_SPIN_LOCK_UNLOCKED
};
@@ -384,7 +392,7 @@ static char *__fetch_rtas_last_error(char *altbuf)
save_args = rtas.args;
rtas.args = err_args;
- enter_rtas(__pa(&rtas.args));
+ do_enter_rtas(__pa(&rtas.args));
err_args = rtas.args;
rtas.args = save_args;
@@ -430,7 +438,7 @@ va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
for (i = 0; i < nret; ++i)
args->rets[i] = 0;
- enter_rtas(__pa(args));
+ do_enter_rtas(__pa(args));
}
void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
@@ -1138,7 +1146,7 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
flags = lock_rtas();
rtas.args = args;
- enter_rtas(__pa(&rtas.args));
+ do_enter_rtas(__pa(&rtas.args));
args = rtas.args;
/* A -1 return code indicates that the last command couldn't
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 9ded046edb0e..3f851fa8f5f1 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -214,7 +214,7 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
regs->gpr[0] = __NR_restart_syscall;
else
regs->gpr[3] = regs->orig_gpr3;
- regs->nip -= 4;
+ regs_add_return_ip(regs, -4);
regs->result = 0;
} else {
if (trap_is_scv(regs)) {
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index dca66481d0c2..4a62faefba0f 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -720,6 +720,9 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
/* This returns like rt_sigreturn */
set_thread_flag(TIF_RESTOREALL);
+
+ return_ip_or_msr_changed();
+
return 0;
efault_out:
@@ -832,6 +835,9 @@ SYSCALL_DEFINE0(rt_sigreturn)
goto badframe;
set_thread_flag(TIF_RESTOREALL);
+
+ return_ip_or_msr_changed();
+
return 0;
badframe_block:
@@ -957,12 +963,15 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
if (err)
goto badframe;
+ return_ip_or_msr_changed();
+
return 0;
badframe_block:
user_write_access_end();
badframe:
signal_fault(current, regs, "handle_rt_signal64", frame);
+ return_ip_or_msr_changed();
return 1;
}
diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index a552c9e68d7e..bf4ae0f0e36c 100644
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -114,7 +114,8 @@ SYSCALL_DEFINE0(switch_endian)
{
struct thread_info *ti;
- current->thread.regs->msr ^= MSR_LE;
+ regs_set_return_msr(current->thread.regs,
+ current->thread.regs->msr ^ MSR_LE);
/*
* Set TIF_RESTOREALL so that r3 isn't clobbered on return to
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index b4ab95c9e94a..e413f9908664 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1031,7 +1031,7 @@ static void p9_hmi_special_emu(struct pt_regs *regs)
#endif /* !__LITTLE_ENDIAN__ */
/* Go to next instruction */
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
}
#endif /* CONFIG_VSX */
@@ -1476,7 +1476,7 @@ static void do_program_check(struct pt_regs *regs)
if (!(regs->msr & MSR_PR) && /* not user-mode */
report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) {
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
return;
}
_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
@@ -1538,7 +1538,7 @@ static void do_program_check(struct pt_regs *regs)
if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
switch (emulate_instruction(regs)) {
case 0:
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
emulate_single_step(regs);
return;
case -EFAULT:
@@ -1593,7 +1593,7 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception)
if (fixed == 1) {
/* skip over emulated instruction */
- regs->nip += inst_length(reason);
+ regs_add_return_ip(regs, inst_length(reason));
emulate_single_step(regs);
return;
}
@@ -1751,7 +1751,7 @@ DEFINE_INTERRUPT_HANDLER(facility_unavailable_exception)
pr_err("DSCR based mfspr emulation failed\n");
return;
}
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
emulate_single_step(regs);
}
return;
@@ -2044,7 +2044,7 @@ DEFINE_INTERRUPT_HANDLER(altivec_assist_exception)
PPC_WARN_EMULATED(altivec, regs);
err = emulate_altivec(regs);
if (err == 0) {
- regs->nip += 4; /* skip emulated instruction */
+ regs_add_return_ip(regs, 4); /* skip emulated instruction */
emulate_single_step(regs);
return;
}
@@ -2109,7 +2109,7 @@ DEFINE_INTERRUPT_HANDLER(SPEFloatingPointException)
err = do_spe_mathemu(regs);
if (err == 0) {
- regs->nip += 4; /* skip emulated instruction */
+ regs_add_return_ip(regs, 4); /* skip emulated instruction */
emulate_single_step(regs);
return;
}
@@ -2140,10 +2140,10 @@ DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundException)
giveup_spe(current);
preempt_enable();
- regs->nip -= 4;
+ regs_add_return_ip(regs, -4);
err = speround_handler(regs);
if (err == 0) {
- regs->nip += 4; /* skip emulated instruction */
+ regs_add_return_ip(regs, 4); /* skip emulated instruction */
emulate_single_step(regs);
return;
}
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index 54dbefcb4cde..02f8925c7919 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -73,6 +73,8 @@ _GLOBAL(load_up_altivec)
addi r5,r4,THREAD /* Get THREAD */
oris r12,r12,MSR_VEC@h
std r12,_MSR(r1)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
#endif
li r4,1
stb r4,THREAD_LOAD_VEC(r5)
@@ -131,6 +133,8 @@ _GLOBAL(load_up_vsx)
/* enable use of VSX after return */
oris r12,r12,MSR_VSX@h
std r12,_MSR(r1)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
b fast_interrupt_return_srr
#endif /* CONFIG_VSX */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 28a80d240b76..efd95b867210 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4461,6 +4461,9 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
vcpu->arch.state = KVMPPC_VCPU_NOTREADY;
atomic_dec(&kvm->arch.vcpus_running);
+
+ srr_regs_clobbered();
+
return r;
}
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index d7733b07f489..4f5879a1f5b9 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -1848,6 +1848,7 @@ static int kvmppc_vcpu_run_pr(struct kvm_vcpu *vcpu)
/* Make sure we save the guest TAR/EBB/DSCR state */
kvmppc_giveup_fac(vcpu, FSCR_TAR_LG);
+ srr_regs_clobbered();
out:
vcpu->mode = OUTSIDE_GUEST_MODE;
return ret;
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 45bda2520755..90fa3878299a 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -3203,7 +3203,7 @@ void emulate_update_regs(struct pt_regs *regs, struct instruction_op *op)
default:
WARN_ON_ONCE(1);
}
- regs->nip = next_pc;
+ regs_set_return_ip(regs, next_pc);
}
NOKPROBE_SYMBOL(emulate_update_regs);
@@ -3480,6 +3480,8 @@ int emulate_step(struct pt_regs *regs, struct ppc_inst instr)
unsigned long val;
unsigned long ea;
+ return_ip_or_msr_changed();
+
r = analyse_instr(&op, regs, instr);
if (r < 0)
return r;
diff --git a/arch/powerpc/math-emu/math.c b/arch/powerpc/math-emu/math.c
index 327165f26ca6..36761bd00f38 100644
--- a/arch/powerpc/math-emu/math.c
+++ b/arch/powerpc/math-emu/math.c
@@ -453,7 +453,7 @@ do_mathemu(struct pt_regs *regs)
break;
}
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
return 0;
illegal:
diff --git a/arch/powerpc/platforms/powernv/opal-call.c b/arch/powerpc/platforms/powernv/opal-call.c
index 01401e3da7ca..f812c74c61e5 100644
--- a/arch/powerpc/platforms/powernv/opal-call.c
+++ b/arch/powerpc/platforms/powernv/opal-call.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/percpu.h>
#include <linux/jump_label.h>
+#include <asm/interrupt.h>
#include <asm/opal-api.h>
#include <asm/trace.h>
#include <asm/asm-prototypes.h>
@@ -100,6 +101,9 @@ static int64_t opal_call(int64_t a0, int64_t a1, int64_t a2, int64_t a3,
bool mmu = (msr & (MSR_IR|MSR_DR));
int64_t ret;
+ /* OPAL call / firmware may use SRR and/or HSRR */
+ srr_regs_clobbered();
+
msr &= ~MSR_EE;
if (unlikely(!mmu))
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index 69af73765783..b8f76f3fd994 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -1072,7 +1072,7 @@ int fsl_pci_mcheck_exception(struct pt_regs *regs)
ret = get_kernel_nofault(inst, (void *)regs->nip);
if (!ret && mcheck_handle_load(regs, inst)) {
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
return 1;
}
}
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 04/11] powerpc/64: handle MSR EE and RI in interrupt entry wrapper
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
` (2 preceding siblings ...)
2021-05-21 11:44 ` [PATCH v2 03/11] powerpc/64s: avoid reloading (H)SRR registers if they are still valid Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 05/11] powerpc/64: move interrupt return asm to interrupt_64.S Nicholas Piggin
` (6 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
Similarly to the system call change in the previous patch, the mtmsrd to
enable RI can be combined with the mtmsrd to enable EE for interrupts
which enable the latter, which tends to be the important synchronous
interrupts (i.e., page faults).
Do this by enabling EE and RI together at the beginning of the entry
wrapper if PACA_IRQ_HARD_DIS is clear, and just enabling RI if it is set
(which means something wanted EE=0).
Asynchronous interrupts set PACA_IRQ_HARD_DIS, but synchronous ones
leave it unchanged, so by default they always get EE=1 unless they
interrupt a caller that has hard disabled. When the sync interrupt
later calls interrupt_cond_local_irq_enable(), that will not require
another mtmsrd because we already enabled here.
This tends to save one mtmsrd L=1 for synchronous interrupts on 64s.
64e is conceptually unchanged, but it also sets MSR[EE]=1 now in the
interrupt wrapper for synchronous interrupts with the same code.
From: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/interrupt.h | 22 ++++++++++++++++++--
arch/powerpc/kernel/exceptions-64s.S | 30 ----------------------------
2 files changed, 20 insertions(+), 32 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 6e9d18838d56..b9c510187b58 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -126,9 +126,21 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
#endif
#ifdef CONFIG_PPC64
- if (irq_soft_mask_set_return(IRQS_ALL_DISABLED) == IRQS_ENABLED)
+ bool trace_enable = false;
+
+ if (IS_ENABLED(CONFIG_TRACE_IRQFLAGS)) {
+ if (irq_soft_mask_set_return(IRQS_DISABLED) == IRQS_ENABLED)
+ trace_enable = true;
+ } else {
+ irq_soft_mask_set(IRQS_DISABLED);
+ }
+ /* If the interrupt was taken with HARD_DIS set, don't enable MSR[EE] */
+ if (local_paca->irq_happened & PACA_IRQ_HARD_DIS)
+ __hard_RI_enable();
+ else
+ __hard_irq_enable();
+ if (trace_enable)
trace_hardirqs_off();
- local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
if (user_mode(regs)) {
CT_WARN_ON(ct_state() != CONTEXT_USER);
@@ -175,6 +187,10 @@ static inline void interrupt_async_enter_prepare(struct pt_regs *regs, struct in
__ppc64_runlatch_on();
#endif
+#ifdef CONFIG_PPC64
+ /* Ensure interrupt_enter_prepare does not enable MSR[EE] */
+ local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+#endif
interrupt_enter_prepare(regs, state);
irq_enter();
}
@@ -239,6 +255,8 @@ static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct inte
regs->softe = IRQS_ALL_DISABLED;
}
+ __hard_RI_enable();
+
/* Don't do any per-CPU operations until interrupt state is fixed */
if (nmi_disables_ftrace(regs)) {
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 5c18a2a3058d..a2ae14d0600e 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -129,7 +129,6 @@ name:
#define IISIDE .L_IISIDE_\name\() /* Uses SRR0/1 not DAR/DSISR */
#define IDAR .L_IDAR_\name\() /* Uses DAR (or SRR0) */
#define IDSISR .L_IDSISR_\name\() /* Uses DSISR (or SRR1) */
-#define ISET_RI .L_ISET_RI_\name\() /* Run common code w/ MSR[RI]=1 */
#define IBRANCH_TO_COMMON .L_IBRANCH_TO_COMMON_\name\() /* ENTRY branch to common */
#define IREALMODE_COMMON .L_IREALMODE_COMMON_\name\() /* Common runs in realmode */
#define IMASK .L_IMASK_\name\() /* IRQ soft-mask bit */
@@ -174,9 +173,6 @@ do_define_int n
.ifndef IDSISR
IDSISR=0
.endif
- .ifndef ISET_RI
- ISET_RI=1
- .endif
.ifndef IBRANCH_TO_COMMON
IBRANCH_TO_COMMON=1
.endif
@@ -581,11 +577,6 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
stb r10,PACASRR_VALID(r13)
.endif
- .if ISET_RI
- li r10,MSR_RI
- mtmsrd r10,1 /* Set MSR_RI */
- .endif
-
.if ISTACK
.if IKUAP
kuap_save_amr_and_lock r9, r10, cr1, cr0
@@ -906,11 +897,6 @@ INT_DEFINE_BEGIN(system_reset)
IVEC=0x100
IAREA=PACA_EXNMI
IVIRT=0 /* no virt entry point */
- /*
- * MSR_RI is not enabled, because PACA_EXNMI and nmi stack is
- * being used, so a nested NMI exception would corrupt it.
- */
- ISET_RI=0
ISTACK=0
IKVM_REAL=1
INT_DEFINE_END(system_reset)
@@ -991,8 +977,6 @@ EXC_COMMON_BEGIN(system_reset_common)
lhz r10,PACA_IN_NMI(r13)
addi r10,r10,1
sth r10,PACA_IN_NMI(r13)
- li r10,MSR_RI
- mtmsrd r10,1
mr r10,r1
ld r1,PACA_NMI_EMERG_SP(r13)
@@ -1068,12 +1052,6 @@ INT_DEFINE_BEGIN(machine_check_early)
IAREA=PACA_EXMC
IVIRT=0 /* no virt entry point */
IREALMODE_COMMON=1
- /*
- * MSR_RI is not enabled, because PACA_EXMC is being used, so a
- * nested machine check corrupts it. machine_check_common enables
- * MSR_RI.
- */
- ISET_RI=0
ISTACK=0
IDAR=1
IDSISR=1
@@ -1084,7 +1062,6 @@ INT_DEFINE_BEGIN(machine_check)
IVEC=0x200
IAREA=PACA_EXMC
IVIRT=0 /* no virt entry point */
- ISET_RI=0
IDAR=1
IDSISR=1
IKVM_SKIP=1
@@ -1155,9 +1132,6 @@ EXC_COMMON_BEGIN(machine_check_early_common)
BEGIN_FTR_SECTION
bl enable_machine_check
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
- li r10,MSR_RI
- mtmsrd r10,1
-
addi r3,r1,STACK_FRAME_OVERHEAD
bl machine_check_early
std r3,RESULT(r1) /* Save result */
@@ -1245,10 +1219,6 @@ EXC_COMMON_BEGIN(machine_check_common)
* save area: PACA_EXMC instead of PACA_EXGEN.
*/
GEN_COMMON machine_check
-
- /* Enable MSR_RI when finished with PACA_EXMC */
- li r10,MSR_RI
- mtmsrd r10,1
addi r3,r1,STACK_FRAME_OVERHEAD
bl machine_check_exception
b interrupt_return_srr
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 05/11] powerpc/64: move interrupt return asm to interrupt_64.S
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
` (3 preceding siblings ...)
2021-05-21 11:44 ` [PATCH v2 04/11] powerpc/64: handle MSR EE and RI in interrupt entry wrapper Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 06/11] powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE] Nicholas Piggin
` (5 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
The next patch would like to move interrupt return assembly code to a low
location before general text, so move it into its own file and include via
head_64.S
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/head-64.h | 2 +-
arch/powerpc/kernel/entry_64.S | 623 ----------------------------
arch/powerpc/kernel/head_64.S | 5 +-
arch/powerpc/kernel/interrupt_64.S | 636 +++++++++++++++++++++++++++++
4 files changed, 641 insertions(+), 625 deletions(-)
create mode 100644 arch/powerpc/kernel/interrupt_64.S
diff --git a/arch/powerpc/include/asm/head-64.h b/arch/powerpc/include/asm/head-64.h
index 4cb9efa2eb21..242204e12993 100644
--- a/arch/powerpc/include/asm/head-64.h
+++ b/arch/powerpc/include/asm/head-64.h
@@ -16,7 +16,7 @@
.section ".head.data.\name\()","a",@progbits
.endm
.macro use_ftsec name
- .section ".head.text.\name\()"
+ .section ".head.text.\name\()","ax",@progbits
.endm
/*
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 9a1d5e5599d3..15720f8661a1 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -32,7 +32,6 @@
#include <asm/irqflags.h>
#include <asm/hw_irq.h>
#include <asm/context_tracking.h>
-#include <asm/tm.h>
#include <asm/ppc-opcode.h>
#include <asm/barrier.h>
#include <asm/export.h>
@@ -48,410 +47,7 @@
/*
* System calls.
*/
- .section ".toc","aw"
-SYS_CALL_TABLE:
- .tc sys_call_table[TC],sys_call_table
-
-#ifdef CONFIG_COMPAT
-COMPAT_SYS_CALL_TABLE:
- .tc compat_sys_call_table[TC],compat_sys_call_table
-#endif
-
-/* This value is used to mark exception frames on the stack. */
-exception_marker:
- .tc ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
-
.section ".text"
- .align 7
-
-.macro DEBUG_SRR_VALID srr
-#ifdef CONFIG_PPC_RFI_SRR_DEBUG
- .ifc \srr,srr
- mfspr r11,SPRN_SRR0
- ld r12,_NIP(r1)
-100: tdne r11,r12
- EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
- mfspr r11,SPRN_SRR1
- ld r12,_MSR(r1)
-100: tdne r11,r12
- EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
- .else
- mfspr r11,SPRN_HSRR0
- ld r12,_NIP(r1)
-100: tdne r11,r12
- EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
- mfspr r11,SPRN_HSRR1
- ld r12,_MSR(r1)
-100: tdne r11,r12
- EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
- .endif
-#endif
-.endm
-
-#ifdef CONFIG_PPC_BOOK3S
-.macro system_call_vectored name trapnr
- .globl system_call_vectored_\name
-system_call_vectored_\name:
-_ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-BEGIN_FTR_SECTION
- extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
- bne .Ltabort_syscall
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
-#endif
- SCV_INTERRUPT_TO_KERNEL
- mr r10,r1
- ld r1,PACAKSAVE(r13)
- std r10,0(r1)
- std r11,_NIP(r1)
- std r12,_MSR(r1)
- std r0,GPR0(r1)
- std r10,GPR1(r1)
- std r2,GPR2(r1)
- ld r2,PACATOC(r13)
- mfcr r12
- li r11,0
- /* Can we avoid saving r3-r8 in common case? */
- std r3,GPR3(r1)
- std r4,GPR4(r1)
- std r5,GPR5(r1)
- std r6,GPR6(r1)
- std r7,GPR7(r1)
- std r8,GPR8(r1)
- /* Zero r9-r12, this should only be required when restoring all GPRs */
- std r11,GPR9(r1)
- std r11,GPR10(r1)
- std r11,GPR11(r1)
- std r11,GPR12(r1)
- std r9,GPR13(r1)
- SAVE_NVGPRS(r1)
- std r11,_XER(r1)
- std r11,_LINK(r1)
- std r11,_CTR(r1)
-
- li r11,\trapnr
- std r11,_TRAP(r1)
- std r12,_CCR(r1)
- addi r10,r1,STACK_FRAME_OVERHEAD
- ld r11,exception_marker@toc(r2)
- std r11,-16(r10) /* "regshere" marker */
-
-BEGIN_FTR_SECTION
- HMT_MEDIUM
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-
- /*
- * scv enters with MSR[EE]=1 and is immediately considered soft-masked.
- * The entry vector already sets PACAIRQSOFTMASK to IRQS_ALL_DISABLED,
- * and interrupts may be masked and pending already.
- * system_call_exception() will call trace_hardirqs_off() which means
- * interrupts could already have been blocked before trace_hardirqs_off,
- * but this is the best we can do.
- */
-
- /* Calling convention has r9 = orig r0, r10 = regs */
- mr r9,r0
- bl system_call_exception
-
-.Lsyscall_vectored_\name\()_exit:
- addi r4,r1,STACK_FRAME_OVERHEAD
- li r5,1 /* scv */
- bl syscall_exit_prepare
-
- ld r2,_CCR(r1)
- ld r4,_NIP(r1)
- ld r5,_MSR(r1)
-
-BEGIN_FTR_SECTION
- stdcx. r0,0,r1 /* to clear the reservation */
-END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-
-BEGIN_FTR_SECTION
- HMT_MEDIUM_LOW
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-
- cmpdi r3,0
- bne .Lsyscall_vectored_\name\()_restore_regs
-
- /* rfscv returns with LR->NIA and CTR->MSR */
- mtlr r4
- mtctr r5
-
- /* Could zero these as per ABI, but we may consider a stricter ABI
- * which preserves these if libc implementations can benefit, so
- * restore them for now until further measurement is done. */
- ld r0,GPR0(r1)
- ld r4,GPR4(r1)
- ld r5,GPR5(r1)
- ld r6,GPR6(r1)
- ld r7,GPR7(r1)
- ld r8,GPR8(r1)
- /* Zero volatile regs that may contain sensitive kernel data */
- li r9,0
- li r10,0
- li r11,0
- li r12,0
- mtspr SPRN_XER,r0
-
- /*
- * We don't need to restore AMR on the way back to userspace for KUAP.
- * The value of AMR only matters while we're in the kernel.
- */
- mtcr r2
- ld r2,GPR2(r1)
- ld r3,GPR3(r1)
- ld r13,GPR13(r1)
- ld r1,GPR1(r1)
- RFSCV_TO_USER
- b . /* prevent speculative execution */
-
-.Lsyscall_vectored_\name\()_restore_regs:
- li r3,0
- mtmsrd r3,1
- mtspr SPRN_SRR0,r4
- mtspr SPRN_SRR1,r5
-
- ld r3,_CTR(r1)
- ld r4,_LINK(r1)
- ld r5,_XER(r1)
-
- REST_NVGPRS(r1)
- ld r0,GPR0(r1)
- mtcr r2
- mtctr r3
- mtlr r4
- mtspr SPRN_XER,r5
- REST_10GPRS(2, r1)
- REST_2GPRS(12, r1)
- ld r1,GPR1(r1)
- RFI_TO_USER
-.endm
-
-system_call_vectored common 0x3000
-/*
- * We instantiate another entry copy for the SIGILL variant, with TRAP=0x7ff0
- * which is tested by system_call_exception when r0 is -1 (as set by vector
- * entry code).
- */
-system_call_vectored sigill 0x7ff0
-
-
-/*
- * Entered via kernel return set up by kernel/sstep.c, must match entry regs
- */
- .globl system_call_vectored_emulate
-system_call_vectored_emulate:
-_ASM_NOKPROBE_SYMBOL(system_call_vectored_emulate)
- li r10,IRQS_ALL_DISABLED
- stb r10,PACAIRQSOFTMASK(r13)
- b system_call_vectored_common
-#endif
-
- .balign IFETCH_ALIGN_BYTES
- .globl system_call_common_real
-system_call_common_real:
- ld r10,PACAKMSR(r13) /* get MSR value for kernel */
- mtmsrd r10
-
- .balign IFETCH_ALIGN_BYTES
- .globl system_call_common
-system_call_common:
-_ASM_NOKPROBE_SYMBOL(system_call_common)
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-BEGIN_FTR_SECTION
- extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
- bne .Ltabort_syscall
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
-#endif
- mr r10,r1
- ld r1,PACAKSAVE(r13)
- std r10,0(r1)
- std r11,_NIP(r1)
- std r12,_MSR(r1)
- std r0,GPR0(r1)
- std r10,GPR1(r1)
- std r2,GPR2(r1)
-#ifdef CONFIG_PPC_FSL_BOOK3E
-START_BTB_FLUSH_SECTION
- BTB_FLUSH(r10)
-END_BTB_FLUSH_SECTION
-#endif
- ld r2,PACATOC(r13)
- mfcr r12
- li r11,0
- /* Can we avoid saving r3-r8 in common case? */
- std r3,GPR3(r1)
- std r4,GPR4(r1)
- std r5,GPR5(r1)
- std r6,GPR6(r1)
- std r7,GPR7(r1)
- std r8,GPR8(r1)
- /* Zero r9-r12, this should only be required when restoring all GPRs */
- std r11,GPR9(r1)
- std r11,GPR10(r1)
- std r11,GPR11(r1)
- std r11,GPR12(r1)
- std r9,GPR13(r1)
- SAVE_NVGPRS(r1)
- std r11,_XER(r1)
- std r11,_CTR(r1)
- mflr r10
-
- /*
- * This clears CR0.SO (bit 28), which is the error indication on
- * return from this system call.
- */
- rldimi r12,r11,28,(63-28)
- li r11,0xc00
- std r10,_LINK(r1)
- std r11,_TRAP(r1)
- std r12,_CCR(r1)
- addi r10,r1,STACK_FRAME_OVERHEAD
- ld r11,exception_marker@toc(r2)
- std r11,-16(r10) /* "regshere" marker */
-
-#ifdef CONFIG_PPC_BOOK3S
- li r11,1
- stb r11,PACASRR_VALID(r13)
-#endif
-
- /*
- * We always enter kernel from userspace with irq soft-mask enabled and
- * nothing pending. system_call_exception() will call
- * trace_hardirqs_off().
- */
- li r11,IRQS_ALL_DISABLED
- li r12,PACA_IRQ_HARD_DIS
- stb r11,PACAIRQSOFTMASK(r13)
- stb r12,PACAIRQHAPPENED(r13)
-
- /* Calling convention has r9 = orig r0, r10 = regs */
- mr r9,r0
- bl system_call_exception
-
-.Lsyscall_exit:
- addi r4,r1,STACK_FRAME_OVERHEAD
- li r5,0 /* !scv */
- bl syscall_exit_prepare
-
- ld r2,_CCR(r1)
- ld r6,_LINK(r1)
- mtlr r6
-
-#ifdef CONFIG_PPC_BOOK3S
- lbz r4,PACASRR_VALID(r13)
- cmpdi r4,0
- bne 1f
- li r4,0
- stb r4,PACASRR_VALID(r13)
-#endif
- ld r4,_NIP(r1)
- ld r5,_MSR(r1)
- mtspr SPRN_SRR0,r4
- mtspr SPRN_SRR1,r5
-1:
- DEBUG_SRR_VALID srr
-
-BEGIN_FTR_SECTION
- stdcx. r0,0,r1 /* to clear the reservation */
-END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-
- cmpdi r3,0
- bne .Lsyscall_restore_regs
- /* Zero volatile regs that may contain sensitive kernel data */
- li r0,0
- li r4,0
- li r5,0
- li r6,0
- li r7,0
- li r8,0
- li r9,0
- li r10,0
- li r11,0
- li r12,0
- mtctr r0
- mtspr SPRN_XER,r0
-.Lsyscall_restore_regs_cont:
-
-BEGIN_FTR_SECTION
- HMT_MEDIUM_LOW
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-
- /*
- * We don't need to restore AMR on the way back to userspace for KUAP.
- * The value of AMR only matters while we're in the kernel.
- */
- mtcr r2
- ld r2,GPR2(r1)
- ld r3,GPR3(r1)
- ld r13,GPR13(r1)
- ld r1,GPR1(r1)
- RFI_TO_USER
- b . /* prevent speculative execution */
-
-.Lsyscall_restore_regs:
- ld r3,_CTR(r1)
- ld r4,_XER(r1)
- REST_NVGPRS(r1)
- mtctr r3
- mtspr SPRN_XER,r4
- ld r0,GPR0(r1)
- REST_8GPRS(4, r1)
- ld r12,GPR12(r1)
- b .Lsyscall_restore_regs_cont
-
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-.Ltabort_syscall:
- /* Firstly we need to enable TM in the kernel */
- mfmsr r10
- li r9, 1
- rldimi r10, r9, MSR_TM_LG, 63-MSR_TM_LG
- mtmsrd r10, 0
-
- /* tabort, this dooms the transaction, nothing else */
- li r9, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT)
- TABORT(R9)
-
- /*
- * Return directly to userspace. We have corrupted user register state,
- * but userspace will never see that register state. Execution will
- * resume after the tbegin of the aborted transaction with the
- * checkpointed register state.
- */
- li r9, MSR_RI
- andc r10, r10, r9
- mtmsrd r10, 1
- mtspr SPRN_SRR0, r11
- mtspr SPRN_SRR1, r12
- RFI_TO_USER
- b . /* prevent speculative execution */
-#endif
-
-#ifdef CONFIG_PPC_BOOK3S
-_GLOBAL(ret_from_fork_scv)
- bl schedule_tail
- REST_NVGPRS(r1)
- li r3,0 /* fork() return value */
- b .Lsyscall_vectored_common_exit
-#endif
-
-_GLOBAL(ret_from_fork)
- bl schedule_tail
- REST_NVGPRS(r1)
- li r3,0 /* fork() return value */
- b .Lsyscall_exit
-
-_GLOBAL(ret_from_kernel_thread)
- bl schedule_tail
- REST_NVGPRS(r1)
- mtctr r14
- mr r3,r15
-#ifdef PPC64_ELF_ABI_v2
- mr r12,r14
-#endif
- bctrl
- li r3,0
- b .Lsyscall_exit
#ifdef CONFIG_PPC_BOOK3S_64
@@ -668,225 +264,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
addi r1,r1,SWITCH_FRAME_SIZE
blr
- /*
- * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not
- * touched, no exit work created, then this can be used.
- */
- .balign IFETCH_ALIGN_BYTES
- .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_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_srr
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl unrecoverable_exception
- b . /* should not get here */
-#else
- 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_\srr
-interrupt_return_\srr\():
-_ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
- ld r4,_MSR(r1)
- andi. r0,r4,MSR_PR
- beq .Lkernel_interrupt_return_\srr
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl interrupt_exit_user_prepare
- cmpdi r3,0
- bne- .Lrestore_nvgprs_\srr
-
-#ifdef CONFIG_PPC_BOOK3S
-.Lfast_user_interrupt_return_amr_\srr\():
- kuap_user_restore r3, r4
-#endif
-.Lfast_user_interrupt_return_\srr\():
-
-BEGIN_FTR_SECTION
- ld r10,_PPR(r1)
- mtspr SPRN_PPR,r10
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-
-#ifdef CONFIG_PPC_BOOK3S
- .ifc \srr,srr
- lbz r4,PACASRR_VALID(r13)
- .else
- lbz r4,PACAHSRR_VALID(r13)
- .endif
- cmpdi r4,0
- li r4,0
- bne 1f
-#endif
- ld r11,_NIP(r1)
- ld r12,_MSR(r1)
- .ifc \srr,srr
- mtspr SPRN_SRR0,r11
- mtspr SPRN_SRR1,r12
-1:
-#ifdef CONFIG_PPC_BOOK3S
- stb r4,PACASRR_VALID(r13)
-#endif
- .else
- mtspr SPRN_HSRR0,r11
- mtspr SPRN_HSRR1,r12
-1:
-#ifdef CONFIG_PPC_BOOK3S
- stb r4,PACAHSRR_VALID(r13)
-#endif
- .endif
- DEBUG_SRR_VALID \srr
-
-BEGIN_FTR_SECTION
- stdcx. r0,0,r1 /* to clear the reservation */
-FTR_SECTION_ELSE
- ldarx r0,0,r1
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-
- ld r3,_CCR(r1)
- ld r4,_LINK(r1)
- ld r5,_CTR(r1)
- ld r6,_XER(r1)
- li r0,0
-
- REST_4GPRS(7, r1)
- REST_2GPRS(11, r1)
- REST_GPR(13, r1)
-
- mtcr r3
- mtlr r4
- mtctr r5
- mtspr SPRN_XER,r6
-
- REST_4GPRS(2, r1)
- 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_\srr\():
- REST_NVGPRS(r1)
- b .Lfast_user_interrupt_return_\srr
-
- .balign IFETCH_ALIGN_BYTES
-.Lkernel_interrupt_return_\srr\():
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl interrupt_exit_kernel_prepare
-
-.Lfast_kernel_interrupt_return_\srr\():
- cmpdi cr1,r3,0
-#ifdef CONFIG_PPC_BOOK3S
- .ifc \srr,srr
- lbz r4,PACASRR_VALID(r13)
- .else
- lbz r4,PACAHSRR_VALID(r13)
- .endif
- cmpdi r4,0
- li r4,0
- bne 1f
-#endif
- ld r11,_NIP(r1)
- ld r12,_MSR(r1)
- .ifc \srr,srr
- mtspr SPRN_SRR0,r11
- mtspr SPRN_SRR1,r12
-1:
-#ifdef CONFIG_PPC_BOOK3S
- stb r4,PACASRR_VALID(r13)
-#endif
- .else
- mtspr SPRN_HSRR0,r11
- mtspr SPRN_HSRR1,r12
-1:
-#ifdef CONFIG_PPC_BOOK3S
- stb r4,PACAHSRR_VALID(r13)
-#endif
- .endif
- DEBUG_SRR_VALID \srr
-
-BEGIN_FTR_SECTION
- stdcx. r0,0,r1 /* to clear the reservation */
-FTR_SECTION_ELSE
- ldarx r0,0,r1
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-
- ld r3,_LINK(r1)
- ld r4,_CTR(r1)
- ld r5,_XER(r1)
- ld r6,_CCR(r1)
- li r0,0
-
- REST_4GPRS(7, r1)
- REST_2GPRS(11, r1)
-
- mtlr r3
- mtctr r4
- mtspr SPRN_XER,r5
-
- /*
- * Leaving a stale exception_marker on the stack can confuse
- * the reliable stack unwinder later on. Clear it.
- */
- std r0,STACK_FRAME_OVERHEAD-16(r1)
-
- REST_4GPRS(2, r1)
-
- bne- cr1,1f /* emulate stack store */
- mtcr r6
- 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: /*
- * Emulate stack store with update. New r1 value was already calculated
- * and updated in our interrupt regs by emulate_loadstore, but we can't
- * store the previous value of r1 to the stack before re-loading our
- * registers from it, otherwise they could be clobbered. Use
- * PACA_EXGEN as temporary storage to hold the store data, as
- * interrupts are disabled here so it won't be clobbered.
- */
- mtcr r6
- std r9,PACA_EXGEN+0(r13)
- addi r9,r1,INT_FRAME_SIZE /* get original r1 */
- REST_GPR(6, r1)
- REST_GPR(0, r1)
- REST_GPR(1, r1)
- 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
/*
* On CHRP, the Run-Time Abstraction Services (RTAS) have to be
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index ece7f97bafff..d49c25daf1c0 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -194,8 +194,9 @@ CLOSE_FIXED_SECTION(first_256B)
/* This value is used to mark exception frames on the stack. */
.section ".toc","aw"
+/* This value is used to mark exception frames on the stack. */
exception_marker:
- .tc ID_72656773_68657265[TC],0x7265677368657265
+ .tc ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
.previous
/*
@@ -211,6 +212,8 @@ OPEN_TEXT_SECTION(0x100)
USE_TEXT_SECTION()
+#include "interrupt_64.S"
+
#ifdef CONFIG_PPC_BOOK3E
/*
* The booting_thread_hwid holds the thread id we want to boot in cpu
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
new file mode 100644
index 000000000000..83826775d239
--- /dev/null
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -0,0 +1,636 @@
+#include <asm/ppc_asm.h>
+#include <asm/head-64.h>
+#include <asm/bug.h>
+#include <asm/hw_irq.h>
+#include <asm/tm.h>
+#include <asm/mmu.h>
+#include <asm/asm-offsets.h>
+#ifdef CONFIG_PPC_BOOK3S
+#include <asm/exception-64s.h>
+#else
+#include <asm/exception-64e.h>
+#endif
+#include <asm/ptrace.h>
+#include <asm/head-64.h>
+#include <asm/feature-fixups.h>
+#include <asm/kup.h>
+
+ .section ".toc","aw"
+SYS_CALL_TABLE:
+ .tc sys_call_table[TC],sys_call_table
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYS_CALL_TABLE:
+ .tc compat_sys_call_table[TC],compat_sys_call_table
+#endif
+ .previous
+
+ .align 7
+
+.macro DEBUG_SRR_VALID srr
+#ifdef CONFIG_PPC_RFI_SRR_DEBUG
+ .ifc \srr,srr
+ mfspr r11,SPRN_SRR0
+ ld r12,_NIP(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ mfspr r11,SPRN_SRR1
+ ld r12,_MSR(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ .else
+ mfspr r11,SPRN_HSRR0
+ ld r12,_NIP(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ mfspr r11,SPRN_HSRR1
+ ld r12,_MSR(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ .endif
+#endif
+.endm
+
+#ifdef CONFIG_PPC_BOOK3S
+.macro system_call_vectored name trapnr
+ .globl system_call_vectored_\name
+system_call_vectored_\name:
+_ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+BEGIN_FTR_SECTION
+ extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
+ bne .Ltabort_syscall
+END_FTR_SECTION_IFSET(CPU_FTR_TM)
+#endif
+ SCV_INTERRUPT_TO_KERNEL
+ mr r10,r1
+ ld r1,PACAKSAVE(r13)
+ std r10,0(r1)
+ std r11,_NIP(r1)
+ std r12,_MSR(r1)
+ std r0,GPR0(r1)
+ std r10,GPR1(r1)
+ std r2,GPR2(r1)
+ ld r2,PACATOC(r13)
+ mfcr r12
+ li r11,0
+ /* Can we avoid saving r3-r8 in common case? */
+ std r3,GPR3(r1)
+ std r4,GPR4(r1)
+ std r5,GPR5(r1)
+ std r6,GPR6(r1)
+ std r7,GPR7(r1)
+ std r8,GPR8(r1)
+ /* Zero r9-r12, this should only be required when restoring all GPRs */
+ std r11,GPR9(r1)
+ std r11,GPR10(r1)
+ std r11,GPR11(r1)
+ std r11,GPR12(r1)
+ std r9,GPR13(r1)
+ SAVE_NVGPRS(r1)
+ std r11,_XER(r1)
+ std r11,_LINK(r1)
+ std r11,_CTR(r1)
+
+ li r11,\trapnr
+ std r11,_TRAP(r1)
+ std r12,_CCR(r1)
+ addi r10,r1,STACK_FRAME_OVERHEAD
+ ld r11,exception_marker@toc(r2)
+ std r11,-16(r10) /* "regshere" marker */
+
+BEGIN_FTR_SECTION
+ HMT_MEDIUM
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+ /*
+ * scv enters with MSR[EE]=1 and is immediately considered soft-masked.
+ * The entry vector already sets PACAIRQSOFTMASK to IRQS_ALL_DISABLED,
+ * and interrupts may be masked and pending already.
+ * system_call_exception() will call trace_hardirqs_off() which means
+ * interrupts could already have been blocked before trace_hardirqs_off,
+ * but this is the best we can do.
+ */
+
+ /* Calling convention has r9 = orig r0, r10 = regs */
+ mr r9,r0
+ bl system_call_exception
+
+.Lsyscall_vectored_\name\()_exit:
+ addi r4,r1,STACK_FRAME_OVERHEAD
+ li r5,1 /* scv */
+ bl syscall_exit_prepare
+
+ ld r2,_CCR(r1)
+ ld r4,_NIP(r1)
+ ld r5,_MSR(r1)
+
+BEGIN_FTR_SECTION
+ stdcx. r0,0,r1 /* to clear the reservation */
+END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+
+BEGIN_FTR_SECTION
+ HMT_MEDIUM_LOW
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+ cmpdi r3,0
+ bne .Lsyscall_vectored_\name\()_restore_regs
+
+ /* rfscv returns with LR->NIA and CTR->MSR */
+ mtlr r4
+ mtctr r5
+
+ /* Could zero these as per ABI, but we may consider a stricter ABI
+ * which preserves these if libc implementations can benefit, so
+ * restore them for now until further measurement is done. */
+ ld r0,GPR0(r1)
+ ld r4,GPR4(r1)
+ ld r5,GPR5(r1)
+ ld r6,GPR6(r1)
+ ld r7,GPR7(r1)
+ ld r8,GPR8(r1)
+ /* Zero volatile regs that may contain sensitive kernel data */
+ li r9,0
+ li r10,0
+ li r11,0
+ li r12,0
+ mtspr SPRN_XER,r0
+
+ /*
+ * We don't need to restore AMR on the way back to userspace for KUAP.
+ * The value of AMR only matters while we're in the kernel.
+ */
+ mtcr r2
+ ld r2,GPR2(r1)
+ ld r3,GPR3(r1)
+ ld r13,GPR13(r1)
+ ld r1,GPR1(r1)
+ RFSCV_TO_USER
+ b . /* prevent speculative execution */
+
+.Lsyscall_vectored_\name\()_restore_regs:
+ li r3,0
+ mtmsrd r3,1
+ mtspr SPRN_SRR0,r4
+ mtspr SPRN_SRR1,r5
+
+ ld r3,_CTR(r1)
+ ld r4,_LINK(r1)
+ ld r5,_XER(r1)
+
+ REST_NVGPRS(r1)
+ ld r0,GPR0(r1)
+ mtcr r2
+ mtctr r3
+ mtlr r4
+ mtspr SPRN_XER,r5
+ REST_10GPRS(2, r1)
+ REST_2GPRS(12, r1)
+ ld r1,GPR1(r1)
+ RFI_TO_USER
+.endm
+
+system_call_vectored common 0x3000
+/*
+ * We instantiate another entry copy for the SIGILL variant, with TRAP=0x7ff0
+ * which is tested by system_call_exception when r0 is -1 (as set by vector
+ * entry code).
+ */
+system_call_vectored sigill 0x7ff0
+
+
+/*
+ * Entered via kernel return set up by kernel/sstep.c, must match entry regs
+ */
+ .globl system_call_vectored_emulate
+system_call_vectored_emulate:
+_ASM_NOKPROBE_SYMBOL(system_call_vectored_emulate)
+ li r10,IRQS_ALL_DISABLED
+ stb r10,PACAIRQSOFTMASK(r13)
+ b system_call_vectored_common
+#endif
+
+ .balign IFETCH_ALIGN_BYTES
+ .globl system_call_common_real
+system_call_common_real:
+ ld r10,PACAKMSR(r13) /* get MSR value for kernel */
+ mtmsrd r10
+
+ .balign IFETCH_ALIGN_BYTES
+ .globl system_call_common
+system_call_common:
+_ASM_NOKPROBE_SYMBOL(system_call_common)
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+BEGIN_FTR_SECTION
+ extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
+ bne .Ltabort_syscall
+END_FTR_SECTION_IFSET(CPU_FTR_TM)
+#endif
+ mr r10,r1
+ ld r1,PACAKSAVE(r13)
+ std r10,0(r1)
+ std r11,_NIP(r1)
+ std r12,_MSR(r1)
+ std r0,GPR0(r1)
+ std r10,GPR1(r1)
+ std r2,GPR2(r1)
+#ifdef CONFIG_PPC_FSL_BOOK3E
+START_BTB_FLUSH_SECTION
+ BTB_FLUSH(r10)
+END_BTB_FLUSH_SECTION
+#endif
+ ld r2,PACATOC(r13)
+ mfcr r12
+ li r11,0
+ /* Can we avoid saving r3-r8 in common case? */
+ std r3,GPR3(r1)
+ std r4,GPR4(r1)
+ std r5,GPR5(r1)
+ std r6,GPR6(r1)
+ std r7,GPR7(r1)
+ std r8,GPR8(r1)
+ /* Zero r9-r12, this should only be required when restoring all GPRs */
+ std r11,GPR9(r1)
+ std r11,GPR10(r1)
+ std r11,GPR11(r1)
+ std r11,GPR12(r1)
+ std r9,GPR13(r1)
+ SAVE_NVGPRS(r1)
+ std r11,_XER(r1)
+ std r11,_CTR(r1)
+ mflr r10
+
+ /*
+ * This clears CR0.SO (bit 28), which is the error indication on
+ * return from this system call.
+ */
+ rldimi r12,r11,28,(63-28)
+ li r11,0xc00
+ std r10,_LINK(r1)
+ std r11,_TRAP(r1)
+ std r12,_CCR(r1)
+ addi r10,r1,STACK_FRAME_OVERHEAD
+ ld r11,exception_marker@toc(r2)
+ std r11,-16(r10) /* "regshere" marker */
+
+#ifdef CONFIG_PPC_BOOK3S
+ li r11,1
+ stb r11,PACASRR_VALID(r13)
+#endif
+
+ /*
+ * We always enter kernel from userspace with irq soft-mask enabled and
+ * nothing pending. system_call_exception() will call
+ * trace_hardirqs_off().
+ */
+ li r11,IRQS_ALL_DISABLED
+ li r12,PACA_IRQ_HARD_DIS
+ stb r11,PACAIRQSOFTMASK(r13)
+ stb r12,PACAIRQHAPPENED(r13)
+
+ /* Calling convention has r9 = orig r0, r10 = regs */
+ mr r9,r0
+ bl system_call_exception
+
+.Lsyscall_exit:
+ addi r4,r1,STACK_FRAME_OVERHEAD
+ li r5,0 /* !scv */
+ bl syscall_exit_prepare
+
+ ld r2,_CCR(r1)
+ ld r6,_LINK(r1)
+ mtlr r6
+
+#ifdef CONFIG_PPC_BOOK3S
+ lbz r4,PACASRR_VALID(r13)
+ cmpdi r4,0
+ bne 1f
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+#endif
+ ld r4,_NIP(r1)
+ ld r5,_MSR(r1)
+ mtspr SPRN_SRR0,r4
+ mtspr SPRN_SRR1,r5
+1:
+ DEBUG_SRR_VALID srr
+
+BEGIN_FTR_SECTION
+ stdcx. r0,0,r1 /* to clear the reservation */
+END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+
+ cmpdi r3,0
+ bne .Lsyscall_restore_regs
+ /* Zero volatile regs that may contain sensitive kernel data */
+ li r0,0
+ li r4,0
+ li r5,0
+ li r6,0
+ li r7,0
+ li r8,0
+ li r9,0
+ li r10,0
+ li r11,0
+ li r12,0
+ mtctr r0
+ mtspr SPRN_XER,r0
+.Lsyscall_restore_regs_cont:
+
+BEGIN_FTR_SECTION
+ HMT_MEDIUM_LOW
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+ /*
+ * We don't need to restore AMR on the way back to userspace for KUAP.
+ * The value of AMR only matters while we're in the kernel.
+ */
+ mtcr r2
+ ld r2,GPR2(r1)
+ ld r3,GPR3(r1)
+ ld r13,GPR13(r1)
+ ld r1,GPR1(r1)
+ RFI_TO_USER
+ b . /* prevent speculative execution */
+
+.Lsyscall_restore_regs:
+ ld r3,_CTR(r1)
+ ld r4,_XER(r1)
+ REST_NVGPRS(r1)
+ mtctr r3
+ mtspr SPRN_XER,r4
+ ld r0,GPR0(r1)
+ REST_8GPRS(4, r1)
+ ld r12,GPR12(r1)
+ b .Lsyscall_restore_regs_cont
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+.Ltabort_syscall:
+ /* Firstly we need to enable TM in the kernel */
+ mfmsr r10
+ li r9, 1
+ rldimi r10, r9, MSR_TM_LG, 63-MSR_TM_LG
+ mtmsrd r10, 0
+
+ /* tabort, this dooms the transaction, nothing else */
+ li r9, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT)
+ TABORT(R9)
+
+ /*
+ * Return directly to userspace. We have corrupted user register state,
+ * but userspace will never see that register state. Execution will
+ * resume after the tbegin of the aborted transaction with the
+ * checkpointed register state.
+ */
+ li r9, MSR_RI
+ andc r10, r10, r9
+ mtmsrd r10, 1
+ mtspr SPRN_SRR0, r11
+ mtspr SPRN_SRR1, r12
+ RFI_TO_USER
+ b . /* prevent speculative execution */
+#endif
+
+#ifdef CONFIG_PPC_BOOK3S
+_GLOBAL(ret_from_fork_scv)
+ bl schedule_tail
+ REST_NVGPRS(r1)
+ li r3,0 /* fork() return value */
+ b .Lsyscall_vectored_common_exit
+#endif
+
+_GLOBAL(ret_from_fork)
+ bl schedule_tail
+ REST_NVGPRS(r1)
+ li r3,0 /* fork() return value */
+ b .Lsyscall_exit
+
+_GLOBAL(ret_from_kernel_thread)
+ bl schedule_tail
+ REST_NVGPRS(r1)
+ mtctr r14
+ mr r3,r15
+#ifdef PPC64_ELF_ABI_v2
+ mr r12,r14
+#endif
+ bctrl
+ li r3,0
+ b .Lsyscall_exit
+
+ /*
+ * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not
+ * touched, no exit work created, then this can be used.
+ */
+ .balign IFETCH_ALIGN_BYTES
+ .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_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_srr
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl unrecoverable_exception
+ b . /* should not get here */
+#else
+ 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_\srr
+interrupt_return_\srr\():
+_ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
+ ld r4,_MSR(r1)
+ andi. r0,r4,MSR_PR
+ beq .Lkernel_interrupt_return_\srr
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl interrupt_exit_user_prepare
+ cmpdi r3,0
+ bne- .Lrestore_nvgprs_\srr
+
+#ifdef CONFIG_PPC_BOOK3S
+.Lfast_user_interrupt_return_amr_\srr\():
+ kuap_user_restore r3, r4
+#endif
+.Lfast_user_interrupt_return_\srr\():
+
+BEGIN_FTR_SECTION
+ ld r10,_PPR(r1)
+ mtspr SPRN_PPR,r10
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+#ifdef CONFIG_PPC_BOOK3S
+ .ifc \srr,srr
+ lbz r4,PACASRR_VALID(r13)
+ .else
+ lbz r4,PACAHSRR_VALID(r13)
+ .endif
+ cmpdi r4,0
+ li r4,0
+ bne 1f
+#endif
+ ld r11,_NIP(r1)
+ ld r12,_MSR(r1)
+ .ifc \srr,srr
+ mtspr SPRN_SRR0,r11
+ mtspr SPRN_SRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACASRR_VALID(r13)
+#endif
+ .else
+ mtspr SPRN_HSRR0,r11
+ mtspr SPRN_HSRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACAHSRR_VALID(r13)
+#endif
+ .endif
+ DEBUG_SRR_VALID \srr
+
+BEGIN_FTR_SECTION
+ stdcx. r0,0,r1 /* to clear the reservation */
+FTR_SECTION_ELSE
+ ldarx r0,0,r1
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+
+ ld r3,_CCR(r1)
+ ld r4,_LINK(r1)
+ ld r5,_CTR(r1)
+ ld r6,_XER(r1)
+ li r0,0
+
+ REST_4GPRS(7, r1)
+ REST_2GPRS(11, r1)
+ REST_GPR(13, r1)
+
+ mtcr r3
+ mtlr r4
+ mtctr r5
+ mtspr SPRN_XER,r6
+
+ REST_4GPRS(2, r1)
+ 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_\srr\():
+ REST_NVGPRS(r1)
+ b .Lfast_user_interrupt_return_\srr
+
+ .balign IFETCH_ALIGN_BYTES
+.Lkernel_interrupt_return_\srr\():
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl interrupt_exit_kernel_prepare
+
+.Lfast_kernel_interrupt_return_\srr\():
+ cmpdi cr1,r3,0
+#ifdef CONFIG_PPC_BOOK3S
+ .ifc \srr,srr
+ lbz r4,PACASRR_VALID(r13)
+ .else
+ lbz r4,PACAHSRR_VALID(r13)
+ .endif
+ cmpdi r4,0
+ li r4,0
+ bne 1f
+#endif
+ ld r11,_NIP(r1)
+ ld r12,_MSR(r1)
+ .ifc \srr,srr
+ mtspr SPRN_SRR0,r11
+ mtspr SPRN_SRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACASRR_VALID(r13)
+#endif
+ .else
+ mtspr SPRN_HSRR0,r11
+ mtspr SPRN_HSRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACAHSRR_VALID(r13)
+#endif
+ .endif
+ DEBUG_SRR_VALID \srr
+
+BEGIN_FTR_SECTION
+ stdcx. r0,0,r1 /* to clear the reservation */
+FTR_SECTION_ELSE
+ ldarx r0,0,r1
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+
+ ld r3,_LINK(r1)
+ ld r4,_CTR(r1)
+ ld r5,_XER(r1)
+ ld r6,_CCR(r1)
+ li r0,0
+
+ REST_4GPRS(7, r1)
+ REST_2GPRS(11, r1)
+
+ mtlr r3
+ mtctr r4
+ mtspr SPRN_XER,r5
+
+ /*
+ * Leaving a stale exception_marker on the stack can confuse
+ * the reliable stack unwinder later on. Clear it.
+ */
+ std r0,STACK_FRAME_OVERHEAD-16(r1)
+
+ REST_4GPRS(2, r1)
+
+ bne- cr1,1f /* emulate stack store */
+ mtcr r6
+ 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: /*
+ * Emulate stack store with update. New r1 value was already calculated
+ * and updated in our interrupt regs by emulate_loadstore, but we can't
+ * store the previous value of r1 to the stack before re-loading our
+ * registers from it, otherwise they could be clobbered. Use
+ * PACA_EXGEN as temporary storage to hold the store data, as
+ * interrupts are disabled here so it won't be clobbered.
+ */
+ mtcr r6
+ std r9,PACA_EXGEN+0(r13)
+ addi r9,r1,INT_FRAME_SIZE /* get original r1 */
+ REST_GPR(6, r1)
+ REST_GPR(0, r1)
+ REST_GPR(1, r1)
+ 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
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 06/11] powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE]
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
` (4 preceding siblings ...)
2021-05-21 11:44 ` [PATCH v2 05/11] powerpc/64: move interrupt return asm to interrupt_64.S Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 07/11] powerpc/64s: save one more register in the masked interrupt handler Nicholas Piggin
` (4 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
This extends the MSR[RI]=0 window a little further into the system
call in order to pair RI and EE enabling with a single mtmsrd.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 2 --
arch/powerpc/kernel/interrupt_64.S | 4 ++--
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index a2ae14d0600e..b6e1c46c97d0 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1942,8 +1942,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
mtctr r10
bctr
.else
- li r10,MSR_RI
- mtmsrd r10,1 /* Set RI (EE=0) */
#ifdef CONFIG_RELOCATABLE
__LOAD_HANDLER(r10, system_call_common)
mtctr r10
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
index 83826775d239..3038c831fc5f 100644
--- a/arch/powerpc/kernel/interrupt_64.S
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -284,9 +284,9 @@ END_BTB_FLUSH_SECTION
* trace_hardirqs_off().
*/
li r11,IRQS_ALL_DISABLED
- li r12,PACA_IRQ_HARD_DIS
+ li r12,-1 /* Set MSR_EE and MSR_RI */
stb r11,PACAIRQSOFTMASK(r13)
- stb r12,PACAIRQHAPPENED(r13)
+ mtmsrd r12,1
/* Calling convention has r9 = orig r0, r10 = regs */
mr r9,r0
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 07/11] powerpc/64s: save one more register in the masked interrupt handler
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
` (5 preceding siblings ...)
2021-05-21 11:44 ` [PATCH v2 06/11] powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE] Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 08/11] powerpc/64: allow alternate return locations for soft-masked interrupts Nicholas Piggin
` (3 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
This frees up one more register (and takes advantage of that to
clean things up a little bit).
This register will be used in the following patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 34 ++++++++++++++++------------
1 file changed, 20 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index b6e1c46c97d0..0ba8c2387aac 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2758,7 +2758,6 @@ INT_DEFINE_END(soft_nmi)
* 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
@@ -2793,19 +2792,24 @@ masked_Hinterrupt:
.else
masked_interrupt:
.endif
- lbz r11,PACAIRQHAPPENED(r13)
- or r11,r11,r10
- stb r11,PACAIRQHAPPENED(r13)
+ stw r9,PACA_EXGEN+EX_CCR(r13)
+ lbz r9,PACAIRQHAPPENED(r13)
+ or r9,r9,r10
+ stb r9,PACAIRQHAPPENED(r13)
+
+ .if ! \hsrr
cmpwi r10,PACA_IRQ_DEC
bne 1f
- lis r10,0x7fff
- ori r10,r10,0xffff
- mtspr SPRN_DEC,r10
+ LOAD_REG_IMMEDIATE(r9, 0x7fffffff)
+ mtspr SPRN_DEC,r9
#ifdef CONFIG_PPC_WATCHDOG
+ lwz r9,PACA_EXGEN+EX_CCR(r13)
b soft_nmi_common
#else
b 2f
#endif
+ .endif
+
1: andi. r10,r10,PACA_IRQ_MUST_HARD_MASK
beq 2f
xori r12,r12,MSR_EE /* clear MSR_EE */
@@ -2814,17 +2818,19 @@ masked_interrupt:
.else
mtspr SPRN_SRR1,r12
.endif
- ori r11,r11,PACA_IRQ_HARD_DIS
- stb r11,PACAIRQHAPPENED(r13)
+ ori r9,r9,PACA_IRQ_HARD_DIS
+ stb r9,PACAIRQHAPPENED(r13)
2: /* done */
- li r10,0
+ li r9,0
.if \hsrr
- stb r10,PACAHSRR_VALID(r13)
+ stb r9,PACAHSRR_VALID(r13)
.else
- stb r10,PACASRR_VALID(r13)
+ stb r9,PACASRR_VALID(r13)
.endif
- ld r10,PACA_EXGEN+EX_CTR(r13)
- mtctr r10
+
+ ld r9,PACA_EXGEN+EX_CTR(r13)
+ mtctr r9
+ lwz r9,PACA_EXGEN+EX_CCR(r13)
mtcrf 0x80,r9
std r1,PACAR1(r13)
ld r9,PACA_EXGEN+EX_R9(r13)
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 08/11] powerpc/64: allow alternate return locations for soft-masked interrupts
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
` (6 preceding siblings ...)
2021-05-21 11:44 ` [PATCH v2 07/11] powerpc/64s: save one more register in the masked interrupt handler Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 09/11] powerpc/64: interrupt soft-enable race fix Nicholas Piggin
` (2 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
The exception table fixup adjusts a failed page fault's interrupt return
location if it was taken at an address specified in the exception table,
to a corresponding fixup handler address.
Introduce a variation of that idea which adds a fixup table for NMIs and
soft-masked asynchronous interrupts. This will be used to protect
certain critical sections that are sensitive to being clobbered by
interrupts coming in (due to using the same SPRs and/or irq soft-mask
state).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/interrupt.h | 13 +++++++++
arch/powerpc/include/asm/ppc_asm.h | 8 ++++++
arch/powerpc/kernel/exceptions-64e.S | 37 +++++++++++++++++++++++--
arch/powerpc/kernel/exceptions-64s.S | 41 ++++++++++++++++++++++++++++
arch/powerpc/kernel/vmlinux.lds.S | 10 +++++++
arch/powerpc/lib/Makefile | 2 +-
arch/powerpc/lib/restart_table.c | 29 ++++++++++++++++++++
7 files changed, 137 insertions(+), 3 deletions(-)
create mode 100644 arch/powerpc/lib/restart_table.c
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index b9c510187b58..49d9a6fd1bb9 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -73,6 +73,11 @@
#include <asm/kprobes.h>
#include <asm/runlatch.h>
+#ifdef CONFIG_PPC64
+extern char __end_soft_masked[];
+unsigned long search_kernel_restart_table(unsigned long addr);
+#endif
+
#ifdef CONFIG_PPC_BOOK3S_64
static inline void srr_regs_clobbered(void)
{
@@ -287,6 +292,14 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter
* new work to do (must use irq_work for that).
*/
+#ifdef CONFIG_PPC64
+ if (arch_irq_disabled_regs(regs)) {
+ unsigned long rst = search_kernel_restart_table(regs->nip);
+ if (rst)
+ regs_set_return_ip(regs, rst);
+ }
+#endif
+
#ifdef CONFIG_PPC64
if (nmi_disables_ftrace(regs))
this_cpu_set_ftrace_enabled(state->ftrace_enabled);
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index d6739d700f0a..c9c2c36c1f8f 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -762,6 +762,14 @@ END_FTR_SECTION_NESTED(CPU_FTR_CELL_TB_BUG, CPU_FTR_CELL_TB_BUG, 96)
stringify_in_c(.long (_target) - . ;) \
stringify_in_c(.previous)
+#define RESTART_TABLE(_start, _end, _target) \
+ stringify_in_c(.section __restart_table,"a";)\
+ stringify_in_c(.balign 8;) \
+ stringify_in_c(.llong (_start);) \
+ stringify_in_c(.llong (_end);) \
+ stringify_in_c(.llong (_target);) \
+ stringify_in_c(.previous)
+
#ifdef CONFIG_PPC_FSL_BOOK3E
#define BTB_FLUSH(reg) \
lis reg,BUCSR_INIT@h; \
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index b35c97c7082f..1b79f8a75298 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -901,6 +901,28 @@ kernel_dbg_exc:
bl unknown_exception
b interrupt_return
+.macro SEARCH_RESTART_TABLE
+ LOAD_REG_IMMEDIATE_SYM(r14, r11, __start___restart_table)
+ LOAD_REG_IMMEDIATE_SYM(r15, r11, __stop___restart_table)
+300:
+ cmpd r14,r15
+ beq 302f
+ ld r11,0(r14)
+ cmpld r10,r11
+ blt 301f
+ ld r11,8(r14)
+ cmpld r10,r11
+ bge 301f
+ ld r11,16(r14)
+ b 303f
+301:
+ addi r14,r14,24
+ b 300b
+302:
+ li r11,0
+303:
+.endm
+
/*
* An interrupt came in while soft-disabled; We mark paca->irq_happened
* accordingly and if the interrupt is level sensitive, we hard disable
@@ -909,6 +931,9 @@ kernel_dbg_exc:
*/
.macro masked_interrupt_book3e paca_irq full_mask
+ std r14,PACA_EXGEN+EX_R14(r13)
+ std r15,PACA_EXGEN+EX_R15(r13)
+
lbz r10,PACAIRQHAPPENED(r13)
.if \full_mask == 1
ori r10,r10,\paca_irq | PACA_IRQ_HARD_DIS
@@ -918,15 +943,23 @@ kernel_dbg_exc:
stb r10,PACAIRQHAPPENED(r13)
.if \full_mask == 1
- rldicl r10,r11,48,1 /* clear MSR_EE */
- rotldi r11,r10,16
+ xori r11,r11,MSR_EE /* clear MSR_EE */
mtspr SPRN_SRR1,r11
.endif
+ mfspr r10,SPRN_SRR0
+ SEARCH_RESTART_TABLE
+ cmpdi r11,0
+ beq 1f
+ mtspr SPRN_SRR0,r11 /* return to restart address */
+1:
+
lwz r11,PACA_EXGEN+EX_CR(r13)
mtcr r11
ld r10,PACA_EXGEN+EX_R10(r13)
ld r11,PACA_EXGEN+EX_R11(r13)
+ ld r14,PACA_EXGEN+EX_R14(r13)
+ ld r15,PACA_EXGEN+EX_R15(r13)
mfspr r13,SPRN_SPRG_GEN_SCRATCH
rfi
b .
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 0ba8c2387aac..17a213f25c92 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -664,6 +664,36 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
__GEN_COMMON_BODY \name
.endm
+.macro SEARCH_RESTART_TABLE
+#ifdef CONFIG_RELOCATABLE
+ mr r12,r2
+ ld r2,PACATOC(r13)
+ LOAD_REG_ADDR(r9, __start___restart_table)
+ LOAD_REG_ADDR(r10, __stop___restart_table)
+ mr r2,r12
+#else
+ LOAD_REG_IMMEDIATE_SYM(r9, r12, __start___restart_table)
+ LOAD_REG_IMMEDIATE_SYM(r10, r12, __stop___restart_table)
+#endif
+300:
+ cmpd r9,r10
+ beq 302f
+ ld r12,0(r9)
+ cmpld r11,r12
+ blt 301f
+ ld r12,8(r9)
+ cmpld r11,r12
+ bge 301f
+ ld r12,16(r9)
+ b 303f
+301:
+ addi r9,r9,24
+ b 300b
+302:
+ li r12,0
+303:
+.endm
+
/*
* Restore all registers including H/SRR0/1 saved in a stack frame of a
* standard exception.
@@ -2771,6 +2801,7 @@ EXC_COMMON_BEGIN(soft_nmi_common)
mtmsrd r9,1
kuap_kernel_restore r9, r10
+
EXCEPTION_RESTORE_REGS hsrr=0
RFI_TO_KERNEL
@@ -2828,6 +2859,16 @@ masked_interrupt:
stb r9,PACASRR_VALID(r13)
.endif
+ SEARCH_RESTART_TABLE
+ cmpdi r12,0
+ beq 3f
+ .if \hsrr
+ mtspr SPRN_HSRR0,r12
+ .else
+ mtspr SPRN_SRR0,r12
+ .endif
+3:
+
ld r9,PACA_EXGEN+EX_CTR(r13)
mtctr r9
lwz r9,PACA_EXGEN+EX_CCR(r13)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 72fa3c00229a..16c5e13e00c4 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -9,6 +9,14 @@
#define EMITS_PT_NOTE
#define RO_EXCEPTION_TABLE_ALIGN 0
+#define RESTART_TABLE(align) \
+ . = ALIGN(align); \
+ __restart_table : AT(ADDR(__restart_table) - LOAD_OFFSET) { \
+ __start___restart_table = .; \
+ KEEP(*(__restart_table)) \
+ __stop___restart_table = .; \
+ }
+
#include <asm/page.h>
#include <asm-generic/vmlinux.lds.h>
#include <asm/cache.h>
@@ -124,6 +132,8 @@ SECTIONS
RO_DATA(PAGE_SIZE)
#ifdef CONFIG_PPC64
+ RESTART_TABLE(8)
+
. = ALIGN(8);
__stf_entry_barrier_fixup : AT(ADDR(__stf_entry_barrier_fixup) - LOAD_OFFSET) {
__start___stf_entry_barrier_fixup = .;
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index cc1a8a0f311e..4c92c80454f3 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -42,7 +42,7 @@ obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \
memcpy_power7.o
obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
- memcpy_64.o copy_mc_64.o
+ memcpy_64.o copy_mc_64.o restart_table.o
ifndef CONFIG_PPC_QUEUED_SPINLOCKS
obj64-$(CONFIG_SMP) += locks.o
diff --git a/arch/powerpc/lib/restart_table.c b/arch/powerpc/lib/restart_table.c
new file mode 100644
index 000000000000..3ccb31914036
--- /dev/null
+++ b/arch/powerpc/lib/restart_table.c
@@ -0,0 +1,29 @@
+#include <asm/kprobes.h>
+
+struct restart_table_entry {
+ unsigned long start;
+ unsigned long end;
+ unsigned long fixup;
+};
+
+extern struct restart_table_entry __start___restart_table[];
+extern struct restart_table_entry __stop___restart_table[];
+
+/* Given an address, look for it in the kernel exception table */
+unsigned long search_kernel_restart_table(unsigned long addr)
+{
+ struct restart_table_entry *rte = __start___restart_table;
+
+ while (rte < __stop___restart_table) {
+ unsigned long start = rte->start;
+ unsigned long end = rte->end;
+ unsigned long fixup = rte->fixup;
+
+ if (addr >= start && addr < end)
+ return fixup;
+
+ rte++;
+ }
+ return 0;
+}
+NOKPROBE_SYMBOL(search_kernel_restart_table);
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 09/11] powerpc/64: interrupt soft-enable race fix
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
` (7 preceding siblings ...)
2021-05-21 11:44 ` [PATCH v2 08/11] powerpc/64: allow alternate return locations for soft-masked interrupts Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 10/11] powerpc/64: treat low kernel text as irqs soft-masked Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 11/11] powerpc/64: use interrupt restart table to speed up return from interrupt Nicholas Piggin
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
Prevent interrupt restore from allowing racing hard interrupts going
ahead of previous soft-pending ones, by using the soft-masked restart
handler to allow a store to clear the soft-mask while knowing nothing
is soft-pending.
This probably doesn't matter much in practice, but it's a simple
demonstrator / test case to exercise the restart table logic.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/irq.c | 95 +++++++++++++++++++++++++++++++++++++++
1 file changed, 95 insertions(+)
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 72cb45393ef2..8428caf3194e 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -217,6 +217,100 @@ static inline void replay_soft_interrupts_irqrestore(void)
#define replay_soft_interrupts_irqrestore() replay_soft_interrupts()
#endif
+#ifdef CONFIG_CC_HAS_ASM_GOTO
+notrace void arch_local_irq_restore(unsigned long mask)
+{
+ unsigned char irq_happened;
+
+ /* Write the new soft-enabled value if it is a disable */
+ if (mask) {
+ irq_soft_mask_set(mask);
+ return;
+ }
+
+ /*
+ * After the stb, interrupts are unmasked and there are no interrupts
+ * pending replay. The restart sequence makes this atomic with
+ * respect to soft-masked interrupts. If this was just a simple code
+ * sequence, a soft-masked interrupt could become pending right after
+ * the comparison and before the stb.
+ *
+ * This allows interrupts to be unmasked without hard disabling, and
+ * also without new hard interrupts coming in ahead of pending ones.
+ */
+ asm_volatile_goto(
+"1: \n"
+" lbz 9,%0(13) \n"
+" cmpwi 9,0 \n"
+" bne %l[happened] \n"
+" stb 9,%1(13) \n"
+"2: \n"
+ RESTART_TABLE(1b, 2b, 1b)
+ : : "i" (offsetof(struct paca_struct, irq_happened)),
+ "i" (offsetof(struct paca_struct, irq_soft_mask))
+ : "cr0", "r9"
+ : happened);
+
+ if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+ WARN_ON_ONCE(!(mfmsr() & MSR_EE));
+
+ return;
+
+happened:
+ irq_happened = get_irq_happened();
+ if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+ WARN_ON_ONCE(!irq_happened);
+
+ if (irq_happened == PACA_IRQ_HARD_DIS) {
+ if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+ WARN_ON_ONCE(mfmsr() & MSR_EE);
+ irq_soft_mask_set(IRQS_ENABLED);
+ local_paca->irq_happened = 0;
+ __hard_irq_enable();
+ return;
+ }
+
+ /* Have interrupts to replay, need to hard disable first */
+ if (!(irq_happened & PACA_IRQ_HARD_DIS)) {
+ if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
+ if (!(mfmsr() & MSR_EE)) {
+ /*
+ * An interrupt could have come in and cleared
+ * MSR[EE] and set IRQ_HARD_DIS, so check
+ * IRQ_HARD_DIS again and warn if it is still
+ * clear.
+ */
+ irq_happened = get_irq_happened();
+ WARN_ON_ONCE(!(irq_happened & PACA_IRQ_HARD_DIS));
+ }
+ }
+ __hard_irq_disable();
+ local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+ } else {
+ if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
+ if (WARN_ON_ONCE(mfmsr() & MSR_EE))
+ __hard_irq_disable();
+ }
+ }
+
+ /*
+ * Disable preempt here, so that the below preempt_enable will
+ * perform resched if required (a replayed interrupt may set
+ * need_resched).
+ */
+ preempt_disable();
+ irq_soft_mask_set(IRQS_ALL_DISABLED);
+ trace_hardirqs_off();
+
+ replay_soft_interrupts_irqrestore();
+ local_paca->irq_happened = 0;
+
+ trace_hardirqs_on();
+ irq_soft_mask_set(IRQS_ENABLED);
+ __hard_irq_enable();
+ preempt_enable();
+}
+#else
notrace void arch_local_irq_restore(unsigned long mask)
{
unsigned char irq_happened;
@@ -288,6 +382,7 @@ notrace void arch_local_irq_restore(unsigned long mask)
__hard_irq_enable();
preempt_enable();
}
+#endif
EXPORT_SYMBOL(arch_local_irq_restore);
/*
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 10/11] powerpc/64: treat low kernel text as irqs soft-masked
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
` (8 preceding siblings ...)
2021-05-21 11:44 ` [PATCH v2 09/11] powerpc/64: interrupt soft-enable race fix Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
2021-05-21 11:44 ` [PATCH v2 11/11] powerpc/64: use interrupt restart table to speed up return from interrupt Nicholas Piggin
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
Treat code below __end_soft_masked as soft-masked for the purpose
of alternate return. 64s already mostly does this for scv entry.
This will be used to exit from interrupts without disabling MSR[EE].
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/interrupt.h | 8 ++++++--
arch/powerpc/kernel/exceptions-64e.S | 12 +++++++++++-
arch/powerpc/kernel/exceptions-64s.S | 19 +++++++++++--------
arch/powerpc/kernel/interrupt_64.S | 6 +++++-
4 files changed, 33 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 49d9a6fd1bb9..fe02fbbd6b06 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -160,6 +160,10 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
*/
if (TRAP(regs) != INTERRUPT_PROGRAM)
CT_WARN_ON(ct_state() != CONTEXT_KERNEL);
+ BUG_ON(regs->nip < (unsigned long)__end_soft_masked);
+ /* Move this under a debugging check */
+ if (arch_irq_disabled_regs(regs))
+ BUG_ON(search_kernel_restart_table(regs->nip));
}
#endif
@@ -254,8 +258,8 @@ static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct inte
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !(regs->msr & MSR_PR) &&
- regs->nip < (unsigned long)__end_interrupts) {
- // Kernel code running below __end_interrupts is
+ regs->nip < (unsigned long)__end_soft_masked) {
+ // Kernel code running below __end_soft_masked is
// implicitly soft-masked.
regs->softe = IRQS_ALL_DISABLED;
}
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 1b79f8a75298..22fcd95dd8dc 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -342,7 +342,17 @@ ret_from_mc_except:
#define PROLOG_ADDITION_MASKABLE_GEN(n) \
lbz r10,PACAIRQSOFTMASK(r13); /* are irqs soft-masked? */ \
andi. r10,r10,IRQS_DISABLED; /* yes -> go out of line */ \
- bne masked_interrupt_book3e_##n
+ bne masked_interrupt_book3e_##n; \
+ /* Kernel code below __end_soft_masked is implicitly masked */ \
+ andi. r10,r11,MSR_PR; \
+ bne 1f; /* user -> not masked */ \
+ std r14,PACA_EXGEN+EX_R14(r13); \
+ LOAD_REG_IMMEDIATE_SYM(r14, r10, __end_soft_masked); \
+ mfspr r10,SPRN_SRR0; \
+ cmpld r10,r14; \
+ ld r14,PACA_EXGEN+EX_R14(r13); \
+ blt masked_interrupt_book3e_##n; \
+1:
/*
* Additional regs must be re-loaded from paca before EXCEPTION_COMMON* is
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 17a213f25c92..2d980addc88c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -508,10 +508,13 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
andi. r10,r12,MSR_PR
bne 2f
- /* Kernel code running below __end_interrupts is implicitly
- * soft-masked */
- LOAD_HANDLER(r10, __end_interrupts)
+ /*
+ * Kernel code running below __end_soft_masked is implicitly
+ * soft-masked
+ */
+ LOAD_HANDLER(r10, __end_soft_masked)
cmpld r11,r10
+
li r10,IMASK
blt- 1f
@@ -824,17 +827,17 @@ __start_interrupts:
* scv instructions enter the kernel without changing EE, RI, ME, or HV.
* In particular, this means we can take a maskable interrupt at any point
* in the scv handler, which is unlike any other interrupt. This is solved
- * by treating the instruction addresses below __end_interrupts as being
+ * by treating the instruction addresses below __end_soft_masked as being
* soft-masked.
*
* AIL-0 mode scv exceptions go to 0x17000-0x17fff, but we set AIL-3 and
* ensure scv is never executed with relocation off, which means AIL-0
* should never happen.
*
- * Before leaving the below __end_interrupts text, at least of the following
- * must be true:
+ * Before leaving the following inside-__end_soft_masked text, at least of the
+ * following must be true:
* - MSR[PR]=1 (i.e., return to userspace)
- * - MSR_EE|MSR_RI is set (no reentrant exceptions)
+ * - MSR_EE|MSR_RI is clear (no reentrant exceptions)
* - Standard kernel environment is set up (stack, paca, etc)
*
* Call convention:
@@ -3099,7 +3102,7 @@ kvmppc_skip_Hinterrupt:
USE_FIXED_SECTION(virt_trampolines)
/*
- * All code below __end_interrupts is treated as soft-masked. If
+ * All code below __end_soft_masked is treated as soft-masked. If
* any code runs here with MSR[EE]=1, it must then cope with pending
* soft interrupt being raised (i.e., by ensuring it is replayed).
*
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
index 3038c831fc5f..cf53293c8498 100644
--- a/arch/powerpc/kernel/interrupt_64.S
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -633,4 +633,8 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
interrupt_return_macro srr
#ifdef CONFIG_PPC_BOOK3S
interrupt_return_macro hsrr
-#endif
+#endif /* CONFIG_PPC_BOOK3S */
+
+ .globl __end_soft_masked
+__end_soft_masked:
+DEFINE_FIXED_SYMBOL(__end_soft_masked)
--
2.23.0
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 11/11] powerpc/64: use interrupt restart table to speed up return from interrupt
2021-05-21 11:44 [PATCH v2 00/11] powerpc/64: fast interrupt exits Nicholas Piggin
` (9 preceding siblings ...)
2021-05-21 11:44 ` [PATCH v2 10/11] powerpc/64: treat low kernel text as irqs soft-masked Nicholas Piggin
@ 2021-05-21 11:44 ` Nicholas Piggin
10 siblings, 0 replies; 13+ messages in thread
From: Nicholas Piggin @ 2021-05-21 11:44 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
Use the restart table facility to return from interrupt or system calls
without disabling MSR[EE] or MSR[RI].
Interrupt return asm is put into the low soft-masked region, to prevent
interrupts being processed here, although they are still taken as masked
interrupts which causes SRRs to be clobbered, and a pending soft-masked
interrupt to require replaying.
The return code uses restart table regions to redirct to a fixup handler
rather than continue with the exit, if such an interrupt happens. In
this case the interrupt return is redirected to a fixup handler which
reloads r1 for the interrupt stack and reloads registers and sets state
up to replay the soft-masked interrupt and try the exit again.
Some types of security exit fallback flushes and barriers are currently
unable to cope with reentrant interrupts, e.g., because they store some
state in the scratch SPR which would be clobbered even by masked
interrupts. For now the interrupts-enabled exits are disabled when these
flushes are used.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/hw_irq.h | 13 +-
arch/powerpc/include/asm/interrupt.h | 2 +
arch/powerpc/include/asm/paca.h | 3 +
arch/powerpc/include/asm/ptrace.h | 1 +
arch/powerpc/kernel/asm-offsets.c | 3 +
arch/powerpc/kernel/interrupt.c | 385 ++++++++++++++++++---------
arch/powerpc/kernel/interrupt_64.S | 131 ++++++++-
arch/powerpc/lib/feature-fixups.c | 38 ++-
8 files changed, 430 insertions(+), 146 deletions(-)
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 19bcef666cf6..21cc571ea9c2 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -18,8 +18,17 @@
* PACA flags in paca->irq_happened.
*
* This bits are set when interrupts occur while soft-disabled
- * and allow a proper replay. Additionally, PACA_IRQ_HARD_DIS
- * is set whenever we manually hard disable.
+ * and allow a proper replay.
+ *
+ * The PACA_IRQ_HARD_DIS is set whenever we hard disable. It is almost
+ * always in synch with the MSR[EE] state, except:
+ * - A window in interrupt entry, where hardware disables MSR[EE] and that
+ * must be "reconciled" with the soft mask state.
+ * - NMI interrupts that hit in awkward places, until they fix the state.
+ * - When local irqs are being enabled and state is being fixed up.
+ * - When returning from an interrupt there are some windows where this
+ * can become out of synch, but gets fixed before the RFI or before
+ * executing the next user instruction (see arch/powerpc/kernel/interrupt.c).
*/
#define PACA_IRQ_HARD_DIS 0x01
#define PACA_IRQ_DBELL 0x02
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index fe02fbbd6b06..1220b8e52bae 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -79,6 +79,8 @@ unsigned long search_kernel_restart_table(unsigned long addr);
#endif
#ifdef CONFIG_PPC_BOOK3S_64
+DECLARE_STATIC_KEY_FALSE(interrupt_exit_not_reentrant);
+
static inline void srr_regs_clobbered(void)
{
local_paca->srr_valid = 0;
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index dfc984b0e640..ca0b52e107a8 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -167,6 +167,9 @@ struct paca_struct {
u64 kstack; /* Saved Kernel stack addr */
u64 saved_r1; /* r1 save for RTAS calls or PM or EE=0 */
u64 saved_msr; /* MSR saved here by enter_rtas */
+#ifdef CONFIG_PPC64
+ u64 exit_save_r1; /* Syscall/interrupt R1 save */
+#endif
#ifdef CONFIG_PPC_BOOK3E
u16 trap_save; /* Used when bad stack is encountered */
#endif
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 516117bba4e6..cb2b093dee13 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -52,6 +52,7 @@ struct pt_regs
struct {
#ifdef CONFIG_PPC64
unsigned long ppr;
+ unsigned long exit_result;
#endif
union {
#ifdef CONFIG_PPC_KUAP
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 1c2b869d9d52..0dbf1c9e3fef 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -286,6 +286,9 @@ int main(void)
OFFSET(PACAHWCPUID, paca_struct, hw_cpu_id);
OFFSET(PACAKEXECSTATE, paca_struct, kexec_state);
OFFSET(PACA_DSCR_DEFAULT, paca_struct, dscr_default);
+#ifdef CONFIG_PPC64
+ OFFSET(PACA_EXIT_SAVE_R1, paca_struct, exit_save_r1);
+#endif
#ifdef CONFIG_PPC_BOOK3E
OFFSET(PACA_TRAP_SAVE, paca_struct, trap_save);
#endif
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index 38ae7057d6c2..74c995a42399 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -26,6 +26,83 @@ unsigned long global_dbcr0[NR_CPUS];
typedef long (*syscall_fn)(long, long, long, long, long, long);
+#ifdef CONFIG_PPC_BOOK3S_64
+DEFINE_STATIC_KEY_FALSE(interrupt_exit_not_reentrant);
+static inline bool exit_must_hard_disable(void)
+{
+ return static_branch_unlikely(&interrupt_exit_not_reentrant);
+}
+#else
+static inline bool exit_must_hard_disable(void)
+{
+ return false;
+}
+#endif
+
+/*
+ * local irqs must be disabled. Returns false if the caller must re-enable
+ * them, check for new work, and try again.
+ *
+ * This should be called with local irqs disabled, but if they were previously
+ * enabled when the interrupt handler returns (indicating a process-context /
+ * synchronous interrupt) then irqs_enabled should be true.
+ */
+static notrace __always_inline bool prep_irq_for_user_exit(void)
+{
+ user_enter_irqoff();
+ /* This must be done with RI=1 because tracing may touch vmaps */
+ trace_hardirqs_on();
+
+#ifdef CONFIG_PPC32
+ __hard_EE_RI_disable();
+#else
+ if (exit_must_hard_disable())
+ __hard_EE_RI_disable();
+
+ /* This pattern matches prep_irq_for_idle */
+ if (unlikely(lazy_irq_pending_nocheck())) {
+ if (exit_must_hard_disable()) {
+ local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+ __hard_RI_enable();
+ }
+ trace_hardirqs_off();
+ user_exit_irqoff();
+
+ return false;
+ }
+#endif
+ return true;
+}
+
+/*
+ * restartable is true then EE/RI can be left on because interrupts are handled
+ * with a restart sequence.
+ */
+static notrace __always_inline bool prep_irq_for_kernel_enabled_exit(bool restartable)
+{
+ /* This must be done with RI=1 because tracing may touch vmaps */
+ trace_hardirqs_on();
+
+#ifdef CONFIG_PPC32
+ __hard_EE_RI_disable();
+#else
+ if (exit_must_hard_disable() || !restartable)
+ __hard_EE_RI_disable();
+
+ /* This pattern matches prep_irq_for_idle */
+ if (unlikely(lazy_irq_pending_nocheck())) {
+ if (exit_must_hard_disable() || !restartable) {
+ local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+ __hard_RI_enable();
+ }
+ trace_hardirqs_off();
+
+ return false;
+ }
+#endif
+ return true;
+}
+
/* Has to run notrace because it is entered not completely "reconciled" */
notrace long system_call_exception(long r3, long r4, long r5,
long r6, long r7, long r8,
@@ -144,71 +221,6 @@ notrace long system_call_exception(long r3, long r4, long r5,
return f(r3, r4, r5, r6, r7, r8);
}
-/*
- * local irqs must be disabled. Returns false if the caller must re-enable
- * them, check for new work, and try again.
- *
- * This should be called with local irqs disabled, but if they were previously
- * enabled when the interrupt handler returns (indicating a process-context /
- * synchronous interrupt) then irqs_enabled should be true.
- */
-static notrace __always_inline bool __prep_irq_for_enabled_exit(bool clear_ri)
-{
- /* This must be done with RI=1 because tracing may touch vmaps */
- trace_hardirqs_on();
-
- /* This pattern matches prep_irq_for_idle */
- if (clear_ri)
- __hard_EE_RI_disable();
- else
- __hard_irq_disable();
-#ifdef CONFIG_PPC64
- if (unlikely(lazy_irq_pending_nocheck())) {
- /* Took an interrupt, may have more exit work to do. */
- if (clear_ri)
- __hard_RI_enable();
- trace_hardirqs_off();
- local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
-
- return false;
- }
- local_paca->irq_happened = 0;
- irq_soft_mask_set(IRQS_ENABLED);
-#endif
- return true;
-}
-
-static notrace inline bool prep_irq_for_enabled_exit(bool clear_ri, bool irqs_enabled)
-{
- if (__prep_irq_for_enabled_exit(clear_ri))
- return true;
-
- /*
- * Must replay pending soft-masked interrupts now. Don't just
- * local_irq_enabe(); local_irq_disable(); because if we are
- * returning from an asynchronous interrupt here, another one
- * might hit after irqs are enabled, and it would exit via this
- * same path allowing another to fire, and so on unbounded.
- *
- * If interrupts were enabled when this interrupt exited,
- * indicating a process context (synchronous) interrupt,
- * local_irq_enable/disable can be used, which will enable
- * interrupts rather than keeping them masked (unclear how
- * much benefit this is over just replaying for all cases,
- * because we immediately disable again, so all we're really
- * doing is allowing hard interrupts to execute directly for
- * a very small time, rather than being masked and replayed).
- */
- if (irqs_enabled) {
- local_irq_enable();
- local_irq_disable();
- } else {
- replay_soft_interrupts();
- }
-
- return false;
-}
-
static notrace void booke_load_dbcr0(void)
{
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
@@ -231,57 +243,11 @@ static notrace void booke_load_dbcr0(void)
#endif
}
-/*
- * This should be called after a syscall returns, with r3 the return value
- * from the syscall. If this function returns non-zero, the system call
- * exit assembly should additionally load all GPR registers and CTR and XER
- * from the interrupt frame.
- *
- * The function graph tracer can not trace the return side of this function,
- * because RI=0 and soft mask state is "unreconciled", so it is marked notrace.
- */
-notrace unsigned long syscall_exit_prepare(unsigned long r3,
- struct pt_regs *regs,
- long scv)
+notrace unsigned long syscall_exit_prepare_main(unsigned long r3,
+ struct pt_regs *regs)
{
unsigned long ti_flags;
unsigned long ret = 0;
- bool is_not_scv = !IS_ENABLED(CONFIG_PPC_BOOK3S_64) || !scv;
-
- CT_WARN_ON(ct_state() == CONTEXT_USER);
-
- kuap_assert_locked();
-
- regs->result = r3;
-
- /* Check whether the syscall is issued inside a restartable sequence */
- rseq_syscall(regs);
-
- ti_flags = current_thread_info()->flags;
-
- if (unlikely(r3 >= (unsigned long)-MAX_ERRNO) && is_not_scv) {
- if (likely(!(ti_flags & (_TIF_NOERROR | _TIF_RESTOREALL)))) {
- r3 = -r3;
- regs->ccr |= 0x10000000; /* Set SO bit in CR */
- }
- }
-
- if (unlikely(ti_flags & _TIF_PERSYSCALL_MASK)) {
- if (ti_flags & _TIF_RESTOREALL)
- ret = _TIF_RESTOREALL;
- else
- regs->gpr[3] = r3;
- clear_bits(_TIF_PERSYSCALL_MASK, ¤t_thread_info()->flags);
- } else {
- regs->gpr[3] = r3;
- }
-
- if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE)) {
- do_syscall_trace_leave(regs);
- ret |= _TIF_RESTOREALL;
- }
-
- local_irq_disable();
again:
ti_flags = READ_ONCE(current_thread_info()->flags);
@@ -327,11 +293,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
}
}
- user_enter_irqoff();
-
- /* scv need not set RI=0 because SRRs are not used */
- if (unlikely(!__prep_irq_for_enabled_exit(is_not_scv))) {
- user_exit_irqoff();
+ if (!prep_irq_for_user_exit()) {
local_irq_enable();
local_irq_disable();
goto again;
@@ -352,6 +314,91 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
return ret;
}
+/*
+ * This should be called after a syscall returns, with r3 the return value
+ * from the syscall. If this function returns non-zero, the system call
+ * exit assembly should additionally load all GPR registers and CTR and XER
+ * from the interrupt frame.
+ *
+ * The function graph tracer can not trace the return side of this function,
+ * because RI=0 and soft mask state is "unreconciled", so it is marked notrace.
+ */
+notrace unsigned long syscall_exit_prepare(unsigned long r3,
+ struct pt_regs *regs,
+ long scv)
+{
+ unsigned long ti_flags;
+ unsigned long ret = 0;
+ bool is_not_scv = !IS_ENABLED(CONFIG_PPC_BOOK3S_64) || !scv;
+
+ CT_WARN_ON(ct_state() == CONTEXT_USER);
+
+ kuap_assert_locked();
+
+ regs->result = r3;
+
+ /* Check whether the syscall is issued inside a restartable sequence */
+ rseq_syscall(regs);
+
+ ti_flags = current_thread_info()->flags;
+
+ if (unlikely(r3 >= (unsigned long)-MAX_ERRNO) && is_not_scv) {
+ if (likely(!(ti_flags & (_TIF_NOERROR | _TIF_RESTOREALL)))) {
+ r3 = -r3;
+ regs->ccr |= 0x10000000; /* Set SO bit in CR */
+ }
+ }
+
+ if (unlikely(ti_flags & _TIF_PERSYSCALL_MASK)) {
+ if (ti_flags & _TIF_RESTOREALL)
+ ret = _TIF_RESTOREALL;
+ else
+ regs->gpr[3] = r3;
+ clear_bits(_TIF_PERSYSCALL_MASK, ¤t_thread_info()->flags);
+ } else {
+ regs->gpr[3] = r3;
+ }
+
+ if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE)) {
+ do_syscall_trace_leave(regs);
+ ret |= _TIF_RESTOREALL;
+ }
+
+ local_irq_disable();
+ ret |= syscall_exit_prepare_main(r3, regs);
+
+#ifdef CONFIG_PPC64
+ regs->exit_result = ret;
+#endif
+
+ return ret;
+}
+
+#ifdef CONFIG_PPC64
+notrace unsigned long syscall_exit_restart(unsigned long r3, struct pt_regs *regs)
+{
+ /*
+ * This is called when detecting a soft-pending interrupt as well as
+ * an alternate-return interrupt. So we can't just have the alternate
+ * return path clear SRR1[MSR] and set PACA_IRQ_HARD_DIS (unless
+ * the soft-pending case were to fix things up as well). RI might be
+ * disabled, in which case it gets re-enabled by __hard_irq_disable().
+ */
+ __hard_irq_disable();
+ local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+
+ trace_hardirqs_off();
+ user_exit_irqoff();
+ account_cpu_user_entry();
+
+ BUG_ON(!user_mode(regs));
+
+ regs->exit_result |= syscall_exit_prepare_main(r3, regs);
+
+ return regs->exit_result;
+}
+#endif
+
notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs)
{
unsigned long ti_flags;
@@ -405,10 +452,7 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs)
}
}
- user_enter_irqoff();
-
- if (unlikely(!__prep_irq_for_enabled_exit(true))) {
- user_exit_irqoff();
+ if (!prep_irq_for_user_exit()) {
local_irq_enable();
local_irq_disable();
goto again;
@@ -422,6 +466,10 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs)
account_cpu_user_exit();
+#ifdef CONFIG_PPC64
+ regs->exit_result = ret;
+#endif
+
/* Restore user access locks last */
kuap_user_restore(regs);
kuep_unlock();
@@ -436,6 +484,8 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs)
unsigned long flags;
unsigned long ret = 0;
unsigned long kuap;
+ bool stack_store = current_thread_info()->flags &
+ _TIF_EMULATE_STACK_STORE;
if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x) &&
unlikely(!(regs->msr & MSR_RI)))
@@ -450,11 +500,6 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs)
kuap = kuap_get_and_assert_locked();
- if (unlikely(current_thread_info()->flags & _TIF_EMULATE_STACK_STORE)) {
- clear_bits(_TIF_EMULATE_STACK_STORE, ¤t_thread_info()->flags);
- ret = 1;
- }
-
local_irq_save(flags);
if (!arch_irq_disabled_regs(regs)) {
@@ -469,17 +514,54 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs)
}
}
- if (unlikely(!prep_irq_for_enabled_exit(true, !irqs_disabled_flags(flags))))
+ /*
+ * Stack store exit can't be restarted because the interrupt
+ * stack frame might have been clobbered.
+ */
+ if (!prep_irq_for_kernel_enabled_exit(unlikely(stack_store))) {
+ /*
+ * Replay pending soft-masked interrupts now. Don't
+ * just local_irq_enabe(); local_irq_disable(); because
+ * if we are returning from an asynchronous interrupt
+ * here, another one might hit after irqs are enabled,
+ * and it would exit via this same path allowing
+ * another to fire, and so on unbounded.
+ */
+ hard_irq_disable();
+ replay_soft_interrupts();
+ /* Took an interrupt, may have more exit work to do. */
goto again;
- } else {
- /* Returning to a kernel context with local irqs disabled. */
- __hard_EE_RI_disable();
+ }
#ifdef CONFIG_PPC64
+ /*
+ * An interrupt may clear MSR[EE] and set this concurrently,
+ * but it will be marked pending and the exit will be retried.
+ * This leaves a racy window where MSR[EE]=0 and HARD_DIS is
+ * clear, until interrupt_exit_kernel_restart() calls
+ * hard_irq_disable(), which will set HARD_DIS again.
+ */
+ local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
+
+ } else {
+ if (unlikely(stack_store))
+ __hard_EE_RI_disable();
+ /*
+ * Returning to a kernel context with local irqs disabled.
+ * Here, if EE was enabled in the interrupted context, enable
+ * it on return as well. A problem exists here where a soft
+ * masked interrupt may have cleared MSR[EE] and set HARD_DIS
+ * here, and it will still exist on return to the caller. This
+ * will be resolved by the masked interrupt firing again.
+ */
if (regs->msr & MSR_EE)
local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
-#endif
+#endif /* CONFIG_PPC64 */
}
+ if (unlikely(stack_store)) {
+ clear_bits(_TIF_EMULATE_STACK_STORE, ¤t_thread_info()->flags);
+ ret = 1;
+ }
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
local_paca->tm_scratch = regs->msr;
@@ -494,3 +576,42 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs)
return ret;
}
+
+#ifdef CONFIG_PPC64
+notrace unsigned long interrupt_exit_user_restart(struct pt_regs *regs)
+{
+ __hard_irq_disable();
+ local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+
+ trace_hardirqs_off();
+ user_exit_irqoff();
+ account_cpu_user_entry();
+
+ BUG_ON(!user_mode(regs));
+
+ regs->exit_result |= interrupt_exit_user_prepare(regs);
+
+ return regs->exit_result;
+}
+
+/*
+ * No real need to return a value here because the stack store case does not
+ * get restarted.
+ */
+notrace unsigned long interrupt_exit_kernel_restart(struct pt_regs *regs)
+{
+ __hard_irq_disable();
+ local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ set_kuap(AMR_KUAP_BLOCKED);
+#endif
+
+ if (regs->softe == IRQS_ENABLED)
+ trace_hardirqs_off();
+
+ BUG_ON(user_mode(regs));
+
+ return interrupt_exit_kernel_prepare(regs);
+}
+#endif
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
index cf53293c8498..76b827ae849a 100644
--- a/arch/powerpc/kernel/interrupt_64.S
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -117,9 +117,18 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
bl system_call_exception
.Lsyscall_vectored_\name\()_exit:
- addi r4,r1,STACK_FRAME_OVERHEAD
+ addi r4,r1,STACK_FRAME_OVERHEAD
li r5,1 /* scv */
bl syscall_exit_prepare
+ std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
+.Lsyscall_vectored_\name\()_rst_start:
+ lbz r11,PACAIRQHAPPENED(r13)
+ andi. r11,r11,(~PACA_IRQ_HARD_DIS)@l
+ bne- .Lsyscall_vectored_\name\()_restart
+ li r11,IRQS_ENABLED
+ stb r11,PACAIRQSOFTMASK(r13)
+ li r11,0
+ stb r11,PACAIRQHAPPENED(r13) # clear out possible HARD_DIS
ld r2,_CCR(r1)
ld r4,_NIP(r1)
@@ -169,8 +178,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
b . /* prevent speculative execution */
.Lsyscall_vectored_\name\()_restore_regs:
- li r3,0
- mtmsrd r3,1
mtspr SPRN_SRR0,r4
mtspr SPRN_SRR1,r5
@@ -188,9 +195,26 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
REST_2GPRS(12, r1)
ld r1,GPR1(r1)
RFI_TO_USER
+.Lsyscall_vectored_\name\()_rst_end:
+
+.Lsyscall_vectored_\name\()_restart:
+ GET_PACA(r13)
+ ld r1,PACA_EXIT_SAVE_R1(r13)
+ ld r2,PACATOC(r13)
+ ld r3,RESULT(r1)
+ addi r4,r1,STACK_FRAME_OVERHEAD
+ li r11,IRQS_ALL_DISABLED
+ stb r11,PACAIRQSOFTMASK(r13)
+ bl syscall_exit_restart
+ std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
+ b .Lsyscall_vectored_\name\()_rst_start
+
+RESTART_TABLE(.Lsyscall_vectored_\name\()_rst_start, .Lsyscall_vectored_\name\()_rst_end, .Lsyscall_vectored_\name\()_restart)
+
.endm
system_call_vectored common 0x3000
+
/*
* We instantiate another entry copy for the SIGILL variant, with TRAP=0x7ff0
* which is tested by system_call_exception when r0 is -1 (as set by vector
@@ -293,9 +317,18 @@ END_BTB_FLUSH_SECTION
bl system_call_exception
.Lsyscall_exit:
- addi r4,r1,STACK_FRAME_OVERHEAD
+ addi r4,r1,STACK_FRAME_OVERHEAD
li r5,0 /* !scv */
bl syscall_exit_prepare
+ std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
+.Lsyscall_rst_start:
+ lbz r11,PACAIRQHAPPENED(r13)
+ andi. r11,r11,(~PACA_IRQ_HARD_DIS)@l
+ bne- .Lsyscall_restart
+ li r11,IRQS_ENABLED
+ stb r11,PACAIRQSOFTMASK(r13)
+ li r11,0
+ stb r11,PACAIRQHAPPENED(r13) # clear out possible HARD_DIS
ld r2,_CCR(r1)
ld r6,_LINK(r1)
@@ -362,6 +395,21 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
REST_8GPRS(4, r1)
ld r12,GPR12(r1)
b .Lsyscall_restore_regs_cont
+.Lsyscall_rst_end:
+
+.Lsyscall_restart:
+ GET_PACA(r13)
+ ld r1,PACA_EXIT_SAVE_R1(r13)
+ ld r2,PACATOC(r13)
+ ld r3,RESULT(r1)
+ addi r4,r1,STACK_FRAME_OVERHEAD
+ li r11,IRQS_ALL_DISABLED
+ stb r11,PACAIRQSOFTMASK(r13)
+ bl syscall_exit_restart
+ std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
+ b .Lsyscall_rst_start
+
+RESTART_TABLE(.Lsyscall_rst_start, .Lsyscall_rst_end, .Lsyscall_restart)
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
.Ltabort_syscall:
@@ -449,21 +497,28 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
ld r4,_MSR(r1)
andi. r0,r4,MSR_PR
beq .Lkernel_interrupt_return_\srr
+.Linterrupt_return_\srr\()_user:
addi r3,r1,STACK_FRAME_OVERHEAD
bl interrupt_exit_user_prepare
cmpdi r3,0
bne- .Lrestore_nvgprs_\srr
+.Lrestore_nvgprs_\srr\()_cont:
#ifdef CONFIG_PPC_BOOK3S
.Lfast_user_interrupt_return_amr_\srr\():
kuap_user_restore r3, r4
#endif
-.Lfast_user_interrupt_return_\srr\():
-
-BEGIN_FTR_SECTION
- ld r10,_PPR(r1)
- mtspr SPRN_PPR,r10
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+// .Lfast_user_interrupt_return_\srr\():
+
+ std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
+.Linterrupt_return_\srr\()_user_rst_start:
+ lbz r11,PACAIRQHAPPENED(r13)
+ andi. r11,r11,(~PACA_IRQ_HARD_DIS)@l
+ bne- .Linterrupt_return_\srr\()_user_restart
+ li r11,IRQS_ENABLED
+ stb r11,PACAIRQSOFTMASK(r13)
+ li r11,0
+ stb r11,PACAIRQHAPPENED(r13) # clear out possible HARD_DIS
#ifdef CONFIG_PPC_BOOK3S
.ifc \srr,srr
@@ -494,6 +549,17 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
.endif
DEBUG_SRR_VALID \srr
+.Lfast_user_interrupt_return_\srr\():
+#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG
+ lbz r4,PACAIRQSOFTMASK(r13)
+ tdnei r4,IRQS_ENABLED
+#endif
+
+BEGIN_FTR_SECTION
+ ld r10,_PPR(r1)
+ mtspr SPRN_PPR,r10
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
FTR_SECTION_ELSE
@@ -525,16 +591,44 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
HRFI_TO_USER
.endif
b . /* prevent speculative execution */
+.Linterrupt_return_\srr\()_user_rst_end:
.Lrestore_nvgprs_\srr\():
REST_NVGPRS(r1)
- b .Lfast_user_interrupt_return_\srr
+ b .Lrestore_nvgprs_\srr\()_cont
+
+.Linterrupt_return_\srr\()_user_restart:
+ GET_PACA(r13)
+ ld r1,PACA_EXIT_SAVE_R1(r13)
+ ld r2,PACATOC(r13)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ li r11,IRQS_ALL_DISABLED
+ stb r11,PACAIRQSOFTMASK(r13)
+ bl interrupt_exit_user_restart
+ std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
+ b .Linterrupt_return_\srr\()_user_rst_start
+
+RESTART_TABLE(.Linterrupt_return_\srr\()_user_rst_start, .Linterrupt_return_\srr\()_user_rst_end, .Linterrupt_return_\srr\()_user_restart)
.balign IFETCH_ALIGN_BYTES
.Lkernel_interrupt_return_\srr\():
+.Linterrupt_return_\srr\()_kernel:
addi r3,r1,STACK_FRAME_OVERHEAD
bl interrupt_exit_kernel_prepare
+ std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
+.Linterrupt_return_\srr\()_kernel_rst_start:
+ lbz r11,SOFTE(r1)
+ cmpwi r11,IRQS_ENABLED
+ stb r11,PACAIRQSOFTMASK(r13)
+ bne 1f
+ lbz r11,PACAIRQHAPPENED(r13)
+ andi. r11,r11,(~PACA_IRQ_HARD_DIS)@l
+ bne- .Linterrupt_return_\srr\()_kernel_restart
+ li r11,0
+ stb r11,PACAIRQHAPPENED(r13) # clear out possible HARD_DIS
+1:
+
.Lfast_kernel_interrupt_return_\srr\():
cmpdi cr1,r3,0
#ifdef CONFIG_PPC_BOOK3S
@@ -628,6 +722,21 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
HRFI_TO_KERNEL
.endif
b . /* prevent speculative execution */
+.Linterrupt_return_\srr\()_kernel_rst_end:
+
+.Linterrupt_return_\srr\()_kernel_restart:
+ GET_PACA(r13)
+ ld r1,PACA_EXIT_SAVE_R1(r13)
+ ld r2,PACATOC(r13)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ li r11,IRQS_ALL_DISABLED
+ stb r11,PACAIRQSOFTMASK(r13)
+ bl interrupt_exit_kernel_restart
+ std r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */
+ b .Linterrupt_return_\srr\()_kernel_rst_start
+
+RESTART_TABLE(.Linterrupt_return_\srr\()_kernel_rst_start, .Linterrupt_return_\srr\()_kernel_rst_end, .Linterrupt_return_\srr\()_kernel_restart)
+
.endm
interrupt_return_macro srr
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index fe26f2fa0f3f..fbe94e2d5011 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -17,6 +17,7 @@
#include <linux/stop_machine.h>
#include <asm/cputable.h>
#include <asm/code-patching.h>
+#include <asm/interrupt.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <asm/setup.h>
@@ -228,10 +229,27 @@ static void do_stf_exit_barrier_fixups(enum stf_barrier_type types)
: "unknown");
}
+static bool stf_exit_not_reentrant = false;
+static bool rfi_exit_not_reentrant = false;
+
+static void update_interrupt_exit(void)
+{
+ if (stf_exit_not_reentrant || rfi_exit_not_reentrant)
+ static_branch_enable(&interrupt_exit_not_reentrant);
+ else
+ static_branch_disable(&interrupt_exit_not_reentrant);
+}
+
static int __do_stf_barrier_fixups(void *data)
{
enum stf_barrier_type *types = data;
+ if (*types & STF_BARRIER_FALLBACK || *types & STF_BARRIER_SYNC_ORI)
+ stf_exit_not_reentrant = true;
+ else
+ stf_exit_not_reentrant = false;
+ update_interrupt_exit();
+
do_stf_entry_barrier_fixups(*types);
do_stf_exit_barrier_fixups(*types);
@@ -412,12 +430,19 @@ void do_entry_flush_fixups(enum l1d_flush_type types)
stop_machine(__do_entry_flush_fixups, &types, NULL);
}
-void do_rfi_flush_fixups(enum l1d_flush_type types)
+static int __do_rfi_flush_fixups(void *data)
{
+ enum l1d_flush_type types = *(enum l1d_flush_type *)data;
unsigned int instrs[3], *dest;
long *start, *end;
int i;
+ if (types & L1D_FLUSH_FALLBACK)
+ rfi_exit_not_reentrant = true;
+ else
+ rfi_exit_not_reentrant = false;
+ update_interrupt_exit();
+
start = PTRRELOC(&__start___rfi_flush_fixup);
end = PTRRELOC(&__stop___rfi_flush_fixup);
@@ -456,6 +481,17 @@ void do_rfi_flush_fixups(enum l1d_flush_type types)
: "ori type" :
(types & L1D_FLUSH_MTTRIG) ? "mttrig type"
: "unknown");
+
+ return 0;
+}
+
+void do_rfi_flush_fixups(enum l1d_flush_type types)
+{
+ /*
+ * The interrupt_exit_not_reentrant static branch together with the
+ * patching is not safe to perform while other CPUs are executing.
+ */
+ stop_machine(__do_rfi_flush_fixups, &types, NULL);
}
void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
--
2.23.0
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