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| author |   Christophe Leroy <christophe.leroy@c-s.fr> | 2019-04-30 12:39:02 +0000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2019-05-03 01:20:27 +1000 |
| commit | b86fb88855ea7881314b935df1df6b1ef1bd0c32 (patch) | |
| tree | e2207487af1b98d66207a533c572f5a8c8aa077f /arch/powerpc/kernel/head_8xx.S | |
| parent | powerpc: Fix 32-bit handling of MSR_EE on exceptions (diff) | |
| download | wireguard-linux-b86fb88855ea7881314b935df1df6b1ef1bd0c32.tar.xz wireguard-linux-b86fb88855ea7881314b935df1df6b1ef1bd0c32.zip | |
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 '')
| -rw-r--r-- | arch/powerpc/kernel/head_8xx.S | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 16b4791a2a9f..885be7f3d29a 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -185,8 +185,7 @@ Alignment: /* System call */ . = 0xc00 SystemCall: - EXCEPTION_PROLOG - EXC_XFER_SYS(0xc00, DoSyscall) + SYSCALL_ENTRY 0xc00 /* Single step - not used on 601 */ EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD) |