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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-02-08 16:10:22 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-02-11 13:35:08 +0100 |
| commit | 76249ddc27080b6b835a89cedcc4185b3b5a6b23 (patch) | |
| tree | 19927679b58d817e90a31e622d3ee778b4297bb8 /arch/powerpc/kernel/head_32.h | |
| parent | powerpc/32: Always enable data translation on syscall entry (diff) | |
| download | linux-76249ddc27080b6b835a89cedcc4185b3b5a6b23.tar.xz linux-76249ddc27080b6b835a89cedcc4185b3b5a6b23.zip | |
powerpc/32: On syscall entry, enable instruction translation at the same time as data
On 40x and 8xx, kernel text is pinned.
On book3s/32, kernel text is mapped by BATs.
Enable instruction translation at the same time as data translation, it
makes things simpler.
MSR_RI can also be set at the same time because srr0/srr1 are already
saved and r1 is set properly.
On booke, translation is always on, so at the end all PPC32
have translation on early.
This reduces null_syscall benchmark by 13 cycles on 8xx
(296 ==> 283 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/3fe8891c814103a3549efc1d4e7ffc828bba5993.1612796617.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/kernel/head_32.h')
| -rw-r--r-- | arch/powerpc/kernel/head_32.h | 26 |
1 files changed, 9 insertions, 17 deletions
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index d481e351f006..97d8465eb12a 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -125,9 +125,13 @@ lwz r1,TASK_STACK-THREAD(r12) beq- 99f addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE - LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */ - mtmsr r10 - isync + LOAD_REG_IMMEDIATE(r10, MSR_KERNEL) /* can take exceptions */ + mtspr SPRN_SRR1, r10 + lis r10, 1f@h + ori r10, r10, 1f@l + mtspr SPRN_SRR0, r10 + rfi +1: tovirt(r12, r12) stw r11,GPR1(r1) stw r11,0(r1) @@ -141,9 +145,6 @@ stw r10,_CCR(r11) /* save registers */ #ifdef CONFIG_40x rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */ -#else - LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~MSR_IR) /* can take exceptions */ - mtmsr r10 /* (except for mach check in rtas) */ #endif lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */ stw r2,GPR2(r11) @@ -180,8 +181,6 @@ #endif 3: - lis r11, transfer_to_syscall@h - ori r11, r11, transfer_to_syscall@l #ifdef CONFIG_TRACE_IRQFLAGS /* * If MSR is changing we need to keep interrupts disabled at this point @@ -193,15 +192,8 @@ #else LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE) #endif -#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS) - mtspr SPRN_NRI, r0 -#endif - mtspr SPRN_SRR1,r10 - mtspr SPRN_SRR0,r11 - rfi /* jump to handler, enable MMU */ -#ifdef CONFIG_40x - b . /* Prevent prefetch past rfi */ -#endif + mtmsr r10 + b transfer_to_syscall /* jump to handler */ 99: b ret_from_kernel_syscall .endm |