diff options
| author | Christophe Leroy <[email protected]> | 2021-03-12 12:50:20 +0000 |
|---|---|---|
| committer | Michael Ellerman <[email protected]> | 2021-03-29 13:22:04 +1100 |
| commit | e464d92b292cc61f8f0791cf87d3646204bbb208 (patch) | |
| tree | cd580d707c120a2391b29e0a64e3e4208cf2cad0 | |
| parent | 79f4bb17f18162dd95d6aeb6dc3b7da54d6139aa (diff) | |
powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xx
8xx has registers SPRN_NRI, SPRN_EID and SPRN_EIE for changing
MSR EE and RI.
Use SPRN_EID in exception prolog to set RI.
On an 8xx, it reduces the null_syscall test by 3 cycles.
Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/65f6bda827c2a2abce71ea7e07543e791163da33.1615552866.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/kernel/head_32.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index ac6b391f1493..25ee6b26ef5a 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -107,6 +107,8 @@ #endif #ifdef CONFIG_40x rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */ +#elif defined(CONFIG_PPC_8xx) + mtspr SPRN_EID, r2 /* Set MSR_RI */ #else #ifdef CONFIG_VMAP_STACK li r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */ |