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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-03-12 15:50:40 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-03-29 05:22:09 +0300 |
| commit | 8f6ff5bd9b73a7912356f378adfb85e9a4e7ce65 (patch) | |
| tree | a46116ee5ec3a157e42a87c64a4578c9c765af0b /arch/powerpc/kernel/head_40x.S | |
| parent | bce4c26a4e324cb096a3768cdc3aad4e2552c3d0 (diff) | |
| download | linux-8f6ff5bd9b73a7912356f378adfb85e9a4e7ce65.tar.xz | |
powerpc/32: Only restore non volatile registers when required
Until now, non volatile registers were restored everytime they
were saved, ie using EXC_XFER_STD meant saving and restoring
them while EXC_XFER_LITE meant neither saving not restoring them.
Now that they are always saved, EXC_XFER_STD means to restore
them and EXC_XFER_LITE means to not restore them.
Most of the users of EXC_XFER_STD only need to retrieve the
non volatile registers. For them there is no need to restore
the non volatile registers as they have not been modified.
Only very few exceptions require non volatile registers restore.
Opencode the few places which require saving of non volatile
registers.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d1cb12d8023cc6afc1f07150565571373c04945c.1615552867.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/kernel/head_40x.S')
| -rw-r--r-- | arch/powerpc/kernel/head_40x.S | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S index 7270caff665c..f3e5b462113f 100644 --- a/arch/powerpc/kernel/head_40x.S +++ b/arch/powerpc/kernel/head_40x.S @@ -228,12 +228,18 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt) /* 0x0600 - Alignment Exception */ START_EXCEPTION(0x0600, Alignment) EXCEPTION_PROLOG 0x600 Alignment handle_dar_dsisr=1 - EXC_XFER_STD(0x600, alignment_exception) + prepare_transfer_to_handler + bl alignment_exception + REST_NVGPRS(r1) + b interrupt_return /* 0x0700 - Program Exception */ START_EXCEPTION(0x0700, ProgramCheck) EXCEPTION_PROLOG 0x700 ProgramCheck handle_dar_dsisr=1 - EXC_XFER_STD(0x700, program_check_exception) + prepare_transfer_to_handler + bl program_check_exception + REST_NVGPRS(r1) + b interrupt_return EXCEPTION(0x0800, Trap_08, unknown_exception, EXC_XFER_STD) EXCEPTION(0x0900, Trap_09, unknown_exception, EXC_XFER_STD) |