[External] Re: [PATCH] RISC-V: ACPI: fix early_ioremap to early_memremap

[yunhui cui]

Hi Sunil, Alex

On Tue, Oct 29, 2024 at 12:08 PM Sunil V L <sunilvl at ventanamicro.com> wrote:
>
> On Tue, Oct 29, 2024 at 11:04:49AM +0800, yunhui cui wrote:
> > Hi Alex,
> >
> >
> > On Mon, Oct 28, 2024 at 9:37 PM Alexandre Ghiti <alexghiti at rivosinc.com> wrote:
> > >
> > > Hi Yunhui,
> > >
> > > Sorry for the late reply, I was on vacation last week.
> > >
> > > On Mon, Oct 21, 2024 at 8:45 AM yunhui cui <cuiyunhui at bytedance.com> wrote:
> > > >
> > > > Hi Alex,
> > > >
> > > > On Mon, Oct 14, 2024 at 9:01 PM Alexandre Ghiti <alex at ghiti.fr> wrote:
> > > > >
> > > > > On 14/10/2024 14:30, yunhui cui wrote:
> > > > > > Hi Alex,
> > > > > >
> > > > > > On Mon, Oct 14, 2024 at 8:12 PM Alexandre Ghiti <alex at ghiti.fr> wrote:
> > > > > >> Hi Yunhui,
> > > > > >>
> > > > > >> On 14/10/2024 11:47, Yunhui Cui wrote:
> > > > > >>> When SVPBMT is enabled, __acpi_map_table() will directly access the
> > > > > >>> data in DDR through the IO attribute, rather than through hardware
> > > > > >>> cache consistency, resulting in incorrect data in the obtained ACPI
> > > > > >>> table.
> > > > > >>>
> > > > > >>> The log: ACPI: [ACPI:0x18] Invalid zero length.
> > > > > >>>
> > > > > >>> We do not assume whether the bootloader flushes or not. We should
> > > > > >>> access in a cacheable way instead of maintaining cache consistency
> > > > > >>> by software.
> > > > > >>>
> > > > > >>> Signed-off-by: Yunhui Cui <cuiyunhui at bytedance.com>
> > > > > >>> ---
> > > > > >>>    arch/riscv/kernel/acpi.c | 2 +-
> > > > > >>>    1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > >>>
> > > > > >>> diff --git a/arch/riscv/kernel/acpi.c b/arch/riscv/kernel/acpi.c
> > > > > >>> index 6e0d333f57e5..3177c9af8764 100644
> > > > > >>> --- a/arch/riscv/kernel/acpi.c
> > > > > >>> +++ b/arch/riscv/kernel/acpi.c
> > > > > >>> @@ -210,7 +210,7 @@ void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
> > > > > >>>        if (!size)
> > > > > >>>                return NULL;
> > > > > >>>
> > > > > >>> -     return early_ioremap(phys, size);
> > > > > >>> +     return early_memremap(phys, size);
> > > > > >>>    }
> > > > > >>>
> > > > > >>>    void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
> > > > > >>
> > > > > >> It makes sense to me since with this, we don't have to care about how
> > > > > >> the firmware mapped the table. And it mimics all other architectures
> > > > > >> (arm64, loongarch and x86).
> > > > > >>
> > > > > >> Here is the corresponding fixes tag:
> > > > > >>
> > > > > >> Fixes: 3b426d4b5b14 ("RISC-V: ACPI : Fix for usage of pointers in
> > > > > >> different address space")
> > > > > >>
> > > > > >> With the corresponding fix in __acpi_unmap_table() as pointed by Sunil,
> > > > > >> you can add:
> > > > > >>
> > > > > >> Reviewed-by: Alexandre Ghiti <alexghiti at rivosinc.com>
> > > > > >>
> > > > > >> And regarding the sparse error, I don't see any other architecture
> > > > > >> casting to __iomem, so maybe that's not necessary anymore?
> > > > > > OK. I will make the changes in v2. Regarding the sparse error, I will
> > > > > > use another patch specifically to solve it. Is that okay?
> > > > >
> > > > >
> > > > > If the second patch only consists in casting, I would not use another
> > > > > patch since the patch 2 would fix something introduced in patch 1.
> > > > >
> > > > > But if patch 2 is more complicated,  it may make sense to do as you
> > > > > suggest, the goal is to merge patch 1 asap.
> > > >
> > > > Regarding patch 2, I executed "make & make install" for sparse of the
> > > > riscv arch. I "git cloned" from
> > > > https://github.com/ConchuOD/sparse.git.
> > > > Then when compiling the kernel, the following error was reported:
> > > >
> > > > cd /data00/cyh/linux-next/
> > > > make defconfig
> > > > cp .config build-riscv64/
> > > >
> > > > make O=build-riscv64/ C=1 W=1 arch/riscv/kernel/ drivers/acpi/
> > > > drivers/mailbox/ -j
> > > > make[1]: Entering directory '/data00/cyh/linux-next/build-riscv64'
> > > >   GEN     Makefile
> > > >   CC      scripts/mod/empty.o
> > > >   CC      scripts/mod/devicetable-offsets.s
> > > >   CHECK   ../scripts/mod/empty.c
> > > > invalid argument to '-march': '_zicsr_zifencei'
> > > >
> > > > make[3]: *** [../scripts/Makefile.build:229: scripts/mod/empty.o] Error 1
> > > > make[3]: *** Deleting file 'scripts/mod/empty.o'
> > > > make[3]: *** Waiting for unfinished jobs....
> > > > make[2]: *** [/data00/cyh/linux-next/Makefile:1215: prepare0] Error 2
> > > > make[1]: *** [/data00/cyh/linux-next/Makefile:224: __sub-make] Error 2
> > > >
> > > > Do you know the solution?
> > >
> > > In case you did not find the solution yet, I would say that your
> > > toolchain is too old.
> > >
> > > Let me know if I can help,
> > It may not be a problem of an old compiler. The version of the
> > compiler I am using is 13.2.
> > It is a problem with sparse. When running "sparse --arch=riscv
> > -march=rv64imac_zicsr_zifencei scripts/mod/empty.c", there is an
> > invalid argument for '-march': '_zicsr_zifencei'.
> >
> Hi Yunhui,
>
> I think you need latest sparse. I remember building sparse from latest
> sources to avoid this error.
>
> https://www.kernel.org/doc/html/v4.11/dev-tools/sparse.html
>
> Thanks,
> Sunil

Thank you for your suggestions on sparse. The patch has been sent to
the community. Please refer to:
https://lore.kernel.org/linux-arm-kernel/20241031112030.72647-1-cuiyunhui@bytedance.com/T/.


Thanks,
Yunhui