diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2020-06-11 18:12:03 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-07-22 23:00:27 +1000 |
| commit | 7fa95f9adaee7e5cbb195d3359741120829e488b (patch) | |
| tree | 1ca2d65102ad2c5223afe9a78e3105836982479f /arch/powerpc/include/asm/asm-prototypes.h | |
| parent | b2dc2977cba48990df45e0a96150663d4f342700 (diff) | |
powerpc/64s: system call support for scv/rfscv instructions
Add support for the scv instruction on POWER9 and later CPUs.
For now this implements the zeroth scv vector 'scv 0', as identical to
'sc' system calls, with the exception that LR is not preserved, nor
are volatile CR registers, and error is not indicated with CR0[SO],
but by returning a negative errno.
rfscv is implemented to return from scv type system calls. It can not
be used to return from sc system calls because those are defined to
preserve LR.
getpid syscall throughput on POWER9 is improved by 26% (428 to 318
cycles), largely due to reducing mtmsr and mtspr.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fix ppc64e build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200611081203.995112-3-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/include/asm/asm-prototypes.h')
| -rw-r--r-- | arch/powerpc/include/asm/asm-prototypes.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h index 7d81e86a1e5d..fb47bf5818c8 100644 --- a/arch/powerpc/include/asm/asm-prototypes.h +++ b/arch/powerpc/include/asm/asm-prototypes.h @@ -98,7 +98,7 @@ unsigned long __init early_init(unsigned long dt_ptr); void __init machine_init(u64 dt_ptr); #endif long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8, unsigned long r0, struct pt_regs *regs); -notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *regs); +notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *regs, long scv); notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr); notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsigned long msr); |