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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2019-04-30 15:39:02 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-05-02 18:20:27 +0300 |
| commit | b86fb88855ea7881314b935df1df6b1ef1bd0c32 (patch) | |
| tree | e2207487af1b98d66207a533c572f5a8c8aa077f /arch/powerpc/kernel/head_40x.S | |
| parent | 40530db7c656119b1671aae5bc27811f66f5f424 (diff) | |
| download | linux-b86fb88855ea7881314b935df1df6b1ef1bd0c32.tar.xz | |
powerpc/32: implement fast entry for syscalls on non BOOKE
This patch implements a fast entry for syscalls.
Syscalls don't have to preserve non volatile registers except LR.
This patch then implement a fast entry for syscalls, where
volatile registers get clobbered.
As this entry is dedicated to syscall it always sets MSR_EE
and warns in case MSR_EE was previously off
It also assumes that the call is always from user, system calls are
unexpected from kernel.
The overall series improves null_syscall selftest by 12,5% on an 83xx
and by 17% on a 8xx.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/head_40x.S')
| -rw-r--r-- | arch/powerpc/kernel/head_40x.S | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S index fc332d33112e..cf54b784100d 100644 --- a/arch/powerpc/kernel/head_40x.S +++ b/arch/powerpc/kernel/head_40x.S @@ -348,8 +348,7 @@ _ENTRY(saved_ksp_limit) /* 0x0C00 - System Call Exception */ START_EXCEPTION(0x0C00, SystemCall) - EXCEPTION_PROLOG - EXC_XFER_SYS(0xc00, DoSyscall) + SYSCALL_ENTRY 0xc00 EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_STD) EXCEPTION(0x0E00, Trap_0E, unknown_exception, EXC_XFER_STD) |