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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-02-08 18:10:34 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-02-11 15:35:11 +0300 |
| commit | 4d67facbcbdb3d9e3c9cb82e4ec47fc63d298dd8 (patch) | |
| tree | bc4fcd1888bd1bd6089c5d72bd3200f800cb2340 /arch/powerpc | |
| parent | 6f76a01173ccaa363739f913394d4e138d92d718 (diff) | |
| download | linux-4d67facbcbdb3d9e3c9cb82e4ec47fc63d298dd8.tar.xz | |
powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry
system_call_exception() checks MSR_PR and BUGs if a syscall
is issued from kernel mode.
No need to handle it anymore from the ASM entry code.
null_syscall reduction 2 cycles (348 => 346 cycles)
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1eddb42cb12092b1e3d72608d182c365db3da41d.1612796617.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 30 | ||||
| -rw-r--r-- | arch/powerpc/kernel/head_32.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/kernel/head_booke.h | 3 |
3 files changed, 0 insertions, 36 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index bbf7ecea6fe0..cffe58e63356 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -421,36 +421,6 @@ ret_from_kernel_thread: li r3,0 b ret_from_syscall - /* - * System call was called from kernel. We get here with SRR1 in r9. - * Mark the exception as recoverable once we have retrieved SRR0, - * trap a warning and return ENOSYS with CR[SO] set. - */ - .globl ret_from_kernel_syscall -ret_from_kernel_syscall: - mfspr r9, SPRN_SRR0 - mfspr r10, SPRN_SRR1 -#if !defined(CONFIG_4xx) && !defined(CONFIG_BOOKE) - LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR|MSR_DR)) - mtmsr r11 -#endif - -0: trap - EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING - - li r3, ENOSYS - crset so -#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS) - mtspr SPRN_NRI, r0 -#endif - mtspr SPRN_SRR0, r9 - mtspr SPRN_SRR1, r10 - rfi -#ifdef CONFIG_40x - b . /* Prevent prefetch past rfi */ -#endif -_ASM_NOKPROBE_SYMBOL(ret_from_kernel_syscall) - /* * Top-level page fault handling. * This is in assembler because if do_page_fault tells us that diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index af4978e9d50d..0e0e7b5b93ab 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -118,8 +118,6 @@ .macro SYSCALL_ENTRY trapno mfspr r9, SPRN_SRR1 mfspr r10, SPRN_SRR0 - andi. r11, r9, MSR_PR - beq- 99f LOAD_REG_IMMEDIATE(r11, MSR_KERNEL) /* can take exceptions */ lis r12, 1f@h ori r12, r12, 1f@l @@ -174,7 +172,6 @@ 3: #endif b transfer_to_syscall /* jump to handler */ -99: b ret_from_kernel_syscall .endm .macro save_dar_dsisr_on_stack reg1, reg2, sp diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h index db931f1167aa..bfbd240cc8a2 100644 --- a/arch/powerpc/kernel/head_booke.h +++ b/arch/powerpc/kernel/head_booke.h @@ -106,10 +106,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV) #endif mfspr r9, SPRN_SRR1 BOOKE_CLEAR_BTB(r11) - andi. r11, r9, MSR_PR lwz r11, TASK_STACK - THREAD(r10) rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */ - beq- 99f ALLOC_STACK_FRAME(r11, THREAD_SIZE - INT_FRAME_SIZE) stw r12, _CCR(r11) /* save various registers */ mflr r12 @@ -155,7 +153,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV) 3: b transfer_to_syscall /* jump to handler */ -99: b ret_from_kernel_syscall .endm /* To handle the additional exception priority levels on 40x and Book-E |