[PATCH v4 0/4] riscv, mm: detect svnapot cpu support at runtime

[Qinglin Pan]

Hey Conor,
I think something maybe wrong with my patchset, and I will fix them and 
all hints you have mentioned in other mails in the next version patchset.

Thank you so much for your review.

Yours,
Qinglin

On 8/23/22 5:22 AM, Conor.Dooley at microchip.com wrote:
> On 22/08/2022 16:34, panqinglin2020 at iscas.ac.cn wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>
>> From: Qinglin Pan <panqinglin2020 at iscas.ac.cn>
> 
> Hey Qingling,
> Apologies for yet another mail - but I built allmodconfig
> with CONFIG_SVNAPOT=y and got a build error:
> 
>    CC      arch/riscv/kernel/asm-offsets.s
> In file included from /stuff/linux/arch/riscv/include/asm/tlbflush.h:12,
>                   from /stuff/linux/arch/riscv/include/asm/pgtable.h:108,
>                   from /stuff/linux/include/linux/pgtable.h:6,
>                   from /stuff/linux/include/linux/mm.h:29,
>                   from /stuff/linux/arch/riscv/kernel/asm-offsets.c:10:
> /stuff/linux/arch/riscv/include/asm/pgtable.h: In function 'pte_pfn':
> /stuff/linux/arch/riscv/include/asm/pgtable.h:299:35: error: '_PAGE_NAPOT_SHIFT' undeclared (first use in this function)
>    299 |         ALT_SVNAPOT_PTE_PFN(_val, _PAGE_NAPOT_SHIFT,
>        |                                   ^~~~~~~~~~~~~~~~~
> /stuff/linux/arch/riscv/include/asm/errata_list.h:165:23: note: in definition of macro 'ALT_SVNAPOT_PTE_PFN'
>    165 |                   "i"(_napot_shift))
>        |                       ^~~~~~~~~~~~
> /stuff/linux/arch/riscv/include/asm/pgtable.h:299:35: note: each undeclared identifier is reported only once for each function it appears in
>    299 |         ALT_SVNAPOT_PTE_PFN(_val, _PAGE_NAPOT_SHIFT,
>        |                                   ^~~~~~~~~~~~~~~~~
> /stuff/linux/arch/riscv/include/asm/errata_list.h:165:23: note: in definition of macro 'ALT_SVNAPOT_PTE_PFN'
>    165 |                   "i"(_napot_shift))
>        |                       ^~~~~~~~~~~~
> In file included from /stuff/linux/include/linux/mm.h:29,
>                   from /stuff/linux/arch/riscv/kernel/asm-offsets.c:10:
> /stuff/linux/include/linux/pgtable.h: At top level:
> /stuff/linux/include/linux/pgtable.h:1457:20: error: redefinition of 'p4d_clear_huge'
>   1457 | static inline void p4d_clear_huge(p4d_t *p4d) { }
>        |                    ^~~~~~~~~~~~~~
> In file included from /stuff/linux/include/linux/pgtable.h:6,
>                   from /stuff/linux/include/linux/mm.h:29,
>                   from /stuff/linux/arch/riscv/kernel/asm-offsets.c:10:
> /stuff/linux/arch/riscv/include/asm/pgtable.h:763:20: note: previous definition of 'p4d_clear_huge' with type 'void(p4d_t *)'
>    763 | static inline void p4d_clear_huge(p4d_t *p4d) { }
>        |                    ^~~~~~~~~~~~~~
> make[3]: *** [/stuff/linux/scripts/Makefile.build:117: arch/riscv/kernel/asm-offsets.s] Error 1
> make[2]: *** [/stuff/linux/Makefile:1205: prepare0] Error 2
> make[2]: Leaving directory '/stuff/brsdk/work/linux'
> make[1]: *** [Makefile:222: __sub-make] Error 2
> make[1]: Leaving directory '/stuff/linux'
> make: *** [Makefile:179: allmodconfig] Error 2
> 
>>
>> Svnapot is a RISC-V extension for marking contiguous 4K pages as a non-4K
>> page. This patch set is for using Svnapot in Linux Kernel's boot process
>> and hugetlb fs.
>>
>> This patchset adds a Kconfig item for using Svnapot in
>> "Platform type"->"Svnapot support". Its default value is off, and people can set
>> it on if they allow kernel to detect Svnapot hardware support and leverage it.
>>
>> Tested on:
>>    - qemu rv64 with "Svnapot support" off and svnapot=true.
>>    - qemu rv64 with "Svnapot support" on and svnapot=true.
>>    - qemu rv64 with "Svnapot support" off and svnapot=false.
>>    - qemu rv64 with "Svnapot support" on and svnapot=false.
>>
>> Changes in v2:
>>    - detect Svnapot hardware support at boot time.
>> Changes in v3:
>>    - do linear mapping again if has_svnapot
>> Changes in v4:
>>    - fix some errors/warns reported by checkpatch.pl, thanks @Conor
>>
>> Qinglin Pan (4):
>>    mm: modify pte format for Svnapot
>>    mm: support Svnapot in physical page linear-mapping
>>    mm: support Svnapot in hugetlb page
>>    mm: support Svnapot in huge vmap
>>
>>   arch/riscv/Kconfig                   |  10 +-
>>   arch/riscv/include/asm/errata_list.h |  24 ++-
>>   arch/riscv/include/asm/hugetlb.h     |  30 +++-
>>   arch/riscv/include/asm/hwcap.h       |   1 +
>>   arch/riscv/include/asm/mmu.h         |   1 +
>>   arch/riscv/include/asm/page.h        |   2 +-
>>   arch/riscv/include/asm/pgtable-64.h  |  14 ++
>>   arch/riscv/include/asm/pgtable.h     |  70 +++++++-
>>   arch/riscv/include/asm/vmalloc.h     |  22 +++
>>   arch/riscv/kernel/cpu.c              |   1 +
>>   arch/riscv/kernel/cpufeature.c       |  18 ++
>>   arch/riscv/kernel/setup.c            |  11 +-
>>   arch/riscv/mm/hugetlbpage.c          | 250 ++++++++++++++++++++++++++-
>>   arch/riscv/mm/init.c                 |  47 +++--
>>   14 files changed, 477 insertions(+), 24 deletions(-)
>>
>> --
>> 2.35.1
>>
>>
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>