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authorChristophe Leroy <christophe.leroy@csgroup.eu>2021-02-08 15:10:22 +0000
committerMichael Ellerman <mpe@ellerman.id.au>2021-02-11 23:35:08 +1100
commit76249ddc27080b6b835a89cedcc4185b3b5a6b23 (patch)
tree19927679b58d817e90a31e622d3ee778b4297bb8 /arch/powerpc/kernel/head_32.h
parenteca2411040c1ee15b8882c6427fb4eb5a48ada69 (diff)
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.h26
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