diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2020-02-26 03:35:38 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-04-01 13:42:14 +1100 |
| commit | 702f0980522239bc7fd1360b24f722a90b6b4418 (patch) | |
| tree | 9345ee57b7a02a9fbc220c3e527f6808c3f6d7fe /arch/powerpc/kernel | |
| parent | 6cc0c16d82f889f0083f3608237189afb55b67be (diff) | |
powerpc/64s/exception: Remove lite interrupt return
Regular interrupt return restores NVGPRS whereas lite returns do not.
This is clumsy: most interrupts can return without restoring NVGPRS in
most of the time, but there are special cases that require it (when
registers have been modified by the kernel). So change interrupt
return to not restore NVGPRS, and have interrupt handlers restore them
explicitly in the cases that requires it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-30-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 6 | ||||
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 24 |
2 files changed, 14 insertions, 16 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 5d782acb86d4..95905ed3d86e 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -479,12 +479,6 @@ _ASM_NOKPROBE_SYMBOL(fast_interrupt_return) .globl interrupt_return interrupt_return: _ASM_NOKPROBE_SYMBOL(interrupt_return) - REST_NVGPRS(r1) - - .balign IFETCH_ALIGN_BYTES - .globl interrupt_return_lite -interrupt_return_lite: -_ASM_NOKPROBE_SYMBOL(interrupt_return_lite) ld r4,_MSR(r1) andi. r0,r4,MSR_PR beq .Lkernel_interrupt_return diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 11244031adc5..18bbce143084 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1529,7 +1529,7 @@ EXC_COMMON_BEGIN(hardware_interrupt_common) RUNLATCH_ON addi r3,r1,STACK_FRAME_OVERHEAD bl do_IRQ - b interrupt_return_lite + b interrupt_return GEN_KVM hardware_interrupt @@ -1557,6 +1557,7 @@ EXC_COMMON_BEGIN(alignment_common) GEN_COMMON alignment addi r3,r1,STACK_FRAME_OVERHEAD bl alignment_exception + REST_NVGPRS(r1) /* instruction emulation may change GPRs */ b interrupt_return GEN_KVM alignment @@ -1620,6 +1621,7 @@ EXC_COMMON_BEGIN(program_check_common) 3: addi r3,r1,STACK_FRAME_OVERHEAD bl program_check_exception + REST_NVGPRS(r1) /* instruction emulation may change GPRs */ b interrupt_return GEN_KVM program_check @@ -1716,7 +1718,7 @@ EXC_COMMON_BEGIN(decrementer_common) RUNLATCH_ON addi r3,r1,STACK_FRAME_OVERHEAD bl timer_interrupt - b interrupt_return_lite + b interrupt_return GEN_KVM decrementer @@ -1807,7 +1809,7 @@ EXC_COMMON_BEGIN(doorbell_super_common) #else bl unknown_exception #endif - b interrupt_return_lite + b interrupt_return GEN_KVM doorbell_super @@ -2076,6 +2078,7 @@ EXC_COMMON_BEGIN(emulation_assist_common) GEN_COMMON emulation_assist addi r3,r1,STACK_FRAME_OVERHEAD bl emulation_assist_interrupt + REST_NVGPRS(r1) /* instruction emulation may change GPRs */ b interrupt_return GEN_KVM emulation_assist @@ -2194,7 +2197,7 @@ EXC_COMMON_BEGIN(h_doorbell_common) #else bl unknown_exception #endif - b interrupt_return_lite + b interrupt_return GEN_KVM h_doorbell @@ -2224,7 +2227,7 @@ EXC_COMMON_BEGIN(h_virt_irq_common) RUNLATCH_ON addi r3,r1,STACK_FRAME_OVERHEAD bl do_IRQ - b interrupt_return_lite + b interrupt_return GEN_KVM h_virt_irq @@ -2271,7 +2274,7 @@ EXC_COMMON_BEGIN(performance_monitor_common) RUNLATCH_ON addi r3,r1,STACK_FRAME_OVERHEAD bl performance_monitor_exception - b interrupt_return_lite + b interrupt_return GEN_KVM performance_monitor @@ -2668,6 +2671,7 @@ EXC_COMMON_BEGIN(altivec_assist_common) addi r3,r1,STACK_FRAME_OVERHEAD #ifdef CONFIG_ALTIVEC bl altivec_assist_exception + REST_NVGPRS(r1) /* instruction emulation may change GPRs */ #else bl unknown_exception #endif @@ -3057,7 +3061,7 @@ do_hash_page: cmpdi r3,0 /* see if __hash_page succeeded */ /* Success */ - beq interrupt_return_lite /* Return from exception on success */ + beq interrupt_return /* Return from exception on success */ /* Error */ blt- 13f @@ -3074,7 +3078,7 @@ handle_page_fault: addi r3,r1,STACK_FRAME_OVERHEAD bl do_page_fault cmpdi r3,0 - beq+ interrupt_return_lite + beq+ interrupt_return mr r5,r3 addi r3,r1,STACK_FRAME_OVERHEAD ld r4,_DAR(r1) @@ -3089,9 +3093,9 @@ handle_dabr_fault: bl do_break /* * do_break() may have changed the NV GPRS while handling a breakpoint. - * If so, we need to restore them with their updated values. Don't use - * interrupt_return_lite here. + * If so, we need to restore them with their updated values. */ + REST_NVGPRS(r1) b interrupt_return |