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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/entry_32.S | |
| 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/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index e3d43b6e3197..55fcc70f2cc0 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -122,9 +122,9 @@ transfer_to_syscall: SAVE_NVGPRS(r1) kuep_lock - /* Calling convention has r9 = orig r0, r10 = regs */ - addi r10,r1,STACK_FRAME_OVERHEAD - mr r9,r0 + /* Calling convention has r3 = regs, r4 = orig r0 */ + addi r3,r1,STACK_FRAME_OVERHEAD + mr r4,r0 bl system_call_exception ret_from_syscall: |