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| author |   Rohan McLure <rmclure@linux.ibm.com> | 2022-09-21 16:56:00 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-09-28 19:22:09 +1000 |
| commit | f8971c627b14040e533768985a99f4fd6ffa420f (patch) | |
| tree | b13a12041449c8ac129cc0479be77ded55e82f9e /arch/powerpc/kernel/syscall.c | |
| parent | powerpc: Use common syscall handler type (diff) | |
| download | linux-dev-f8971c627b14040e533768985a99f4fd6ffa420f.tar.xz linux-dev-f8971c627b14040e533768985a99f4fd6ffa420f.zip | |
powerpc: Change system_call_exception calling convention
Change system_call_exception arguments to pass a pointer to a stack
frame container caller state, as well as the original r0, which
determines the number of the syscall. This has been observed to yield
improved performance to passing them by registers, circumventing the
need to allocate a stack frame.
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Retain clearing of high bits of args for compat tasks]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-21-rmclure@linux.ibm.com
Diffstat (limited to 'arch/powerpc/kernel/syscall.c')
| -rw-r--r-- | arch/powerpc/kernel/syscall.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c index 9875486f6168..2c002cbbc676 100644 --- a/arch/powerpc/kernel/syscall.c +++ b/arch/powerpc/kernel/syscall.c @@ -13,10 +13,9 @@ /* Has to run notrace because it is entered not completely "reconciled" */ -notrace long system_call_exception(long r3, long r4, long r5, - long r6, long r7, long r8, - unsigned long r0, struct pt_regs *regs) +notrace long system_call_exception(struct pt_regs *regs, unsigned long r0) { + unsigned long r3, r4, r5, r6, r7, r8; long ret; syscall_fn f; @@ -136,12 +135,6 @@ notrace long system_call_exception(long r3, long r4, long r5, r0 = do_syscall_trace_enter(regs); if (unlikely(r0 >= NR_syscalls)) return regs->gpr[3]; - r3 = regs->gpr[3]; - r4 = regs->gpr[4]; - r5 = regs->gpr[5]; - r6 = regs->gpr[6]; - r7 = regs->gpr[7]; - r8 = regs->gpr[8]; } else if (unlikely(r0 >= NR_syscalls)) { if (unlikely(trap_is_unsupported_scv(regs))) { @@ -152,6 +145,13 @@ notrace long system_call_exception(long r3, long r4, long r5, return -ENOSYS; } + r3 = regs->gpr[3]; + r4 = regs->gpr[4]; + r5 = regs->gpr[5]; + r6 = regs->gpr[6]; + r7 = regs->gpr[7]; + r8 = regs->gpr[8]; + /* May be faster to do array_index_nospec? */ barrier_nospec(); |