Excerpts from Christophe Leroy's message of August 28, 2021 7:59 pm:
>
>
> Le 27/08/2021 à 18:34, Nicholas Piggin a écrit :
>> Introduce a new option CONFIG_PPC_64S_HASH_MMU which allows the 64s hash
>> MMU code to be compiled out if radix is selected and the minimum
>> supported CPU type is POWER9 or higher, and KVM is not selected.
>>
>> This saves 128kB kernel image size (90kB text) on powernv_defconfig
>> minus KVM, 350kB on pseries_defconfig minus KVM, 40kB on a tiny config.
>>
>> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
>> ---
>> arch/powerpc/Kconfig | 1 +
>> arch/powerpc/include/asm/book3s/64/mmu.h | 22 +++++-
>> .../include/asm/book3s/64/tlbflush-hash.h | 7 ++
>> arch/powerpc/include/asm/book3s/pgtable.h | 4 ++
>> arch/powerpc/include/asm/mmu.h | 38 +++++++++--
>> arch/powerpc/include/asm/mmu_context.h | 2 +
>> arch/powerpc/include/asm/paca.h | 8 +++
>> arch/powerpc/kernel/asm-offsets.c | 2 +
>> arch/powerpc/kernel/dt_cpu_ftrs.c | 10 ++-
>> arch/powerpc/kernel/entry_64.S | 4 +-
>> arch/powerpc/kernel/exceptions-64s.S | 16 +++++
>> arch/powerpc/kernel/mce.c | 2 +-
>> arch/powerpc/kernel/mce_power.c | 10 ++-
>> arch/powerpc/kernel/paca.c | 18 ++---
>> arch/powerpc/kernel/process.c | 13 ++--
>> arch/powerpc/kernel/prom.c | 2 +
>> arch/powerpc/kernel/setup_64.c | 4 ++
>> arch/powerpc/kexec/core_64.c | 4 +-
>> arch/powerpc/kexec/ranges.c | 4 ++
>> arch/powerpc/kvm/Kconfig | 1 +
>> arch/powerpc/mm/book3s64/Makefile | 17 +++--
>> arch/powerpc/mm/book3s64/hash_pgtable.c | 1 -
>> arch/powerpc/mm/book3s64/hash_utils.c | 10 ---
>> .../{hash_hugetlbpage.c => hugetlbpage.c} | 6 ++
>> arch/powerpc/mm/book3s64/mmu_context.c | 16 +++++
>> arch/powerpc/mm/book3s64/pgtable.c | 22 +++++-
>> arch/powerpc/mm/book3s64/radix_pgtable.c | 4 ++
>> arch/powerpc/mm/book3s64/slb.c | 16 -----
>> arch/powerpc/mm/copro_fault.c | 2 +
>> arch/powerpc/mm/fault.c | 17 +++++
>> arch/powerpc/mm/pgtable.c | 10 ++-
>> arch/powerpc/platforms/Kconfig.cputype | 20 +++++-
>> arch/powerpc/platforms/cell/Kconfig | 1 +
>> arch/powerpc/platforms/maple/Kconfig | 1 +
>> arch/powerpc/platforms/microwatt/Kconfig | 2 +-
>> arch/powerpc/platforms/pasemi/Kconfig | 1 +
>> arch/powerpc/platforms/powermac/Kconfig | 1 +
>> arch/powerpc/platforms/powernv/Kconfig | 2 +-
>> arch/powerpc/platforms/powernv/idle.c | 2 +
>> arch/powerpc/platforms/powernv/setup.c | 2 +
>> arch/powerpc/platforms/pseries/lpar.c | 68 ++++++++++---------
>> arch/powerpc/platforms/pseries/lparcfg.c | 2 +-
>> arch/powerpc/platforms/pseries/mobility.c | 6 ++
>> arch/powerpc/platforms/pseries/ras.c | 4 ++
>> arch/powerpc/platforms/pseries/reconfig.c | 2 +
>> arch/powerpc/platforms/pseries/setup.c | 6 +-
>> arch/powerpc/xmon/xmon.c | 8 ++-
>> 47 files changed, 310 insertions(+), 111 deletions(-)
>> rename arch/powerpc/mm/book3s64/{hash_hugetlbpage.c => hugetlbpage.c} (95%)
>
> Whaou ! Huge patch.
>
> Several places you should be able to use IS_ENABLED() or simply
> radix_enabled() instead of #ifdefs
> and rely on GCC to opt out stuff when radix_enabled() folds into 'true'.
A lot of it couldn't be done because of data structures but I'm sure I
missed a lot. I will go over it again.
> I may do more detailed comments later when I have time.
Very much appreciated, but let me send out another version before you
get the fine toothed comb out so I don't waste too much of your time.
If there are no objections to the idea from a high level.
Thanks,
Nick
