Re: [PATCH] arm64: acpi: Export symbol for acpi_os_ioremap

[lihuisong (C)]

在 2023/5/26 20:39, Ard Biesheuvel 写道:
> (cc Lorenzo)
>
> On Fri, 26 May 2023 at 14:20, Huisong Li <lihuisong@xxxxxxxxxx> wrote:
> > The driver who calls the acpi_os_ioremap() cannot be compiled if the 'M'
> > is selected for the driver. The compiling log is as follows:
> > -->
> > MODPOST Module.symvers
> > ERROR: modpost: "acpi_os_ioremap" [drivers/soc/hisilicon/xxx.ko] undefined!
> > scripts/Makefile.modpost:136: recipe for target 'Module.symvers' failed
> > make[1]: *** [Module.symvers] Error 1
> >
> > So this patch exports symbol for acpi_os_ioremap.
> That driver does not exist in mainline.

We have an uploading driver [1] that may use it.

[1] 
https://patchwork.kernel.org/project/linux-soc/patch/20230522072211.8894-2-lihuisong@xxxxxxxxxx/

> Why does it need to use acpi_os_ioremap() instead of the ordinary
> memremap/ioremap routines?
This driver needs to ioremap the shared memory space of a PCC subspace.
And @Sudeep suggested that we use this interface.
It is suitable here.
> > Signed-off-by: Huisong Li <lihuisong@xxxxxxxxxx>
> > ---
> >   arch/arm64/kernel/acpi.c | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> > index dba8fcec7f33..ec0414caf3d1 100644
> > --- a/arch/arm64/kernel/acpi.c
> > +++ b/arch/arm64/kernel/acpi.c
> > @@ -354,6 +354,7 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
> >          }
> >          return ioremap_prot(phys, size, pgprot_val(prot));
> >   }
> > +EXPORT_SYMBOL(acpi_os_ioremap);
> >
> >   /*
> >    * Claim Synchronous External Aborts as a firmware first notification.
> > --
> > 2.33.0
> >
> >
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> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
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> .