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

["lihuisong (C)" <lihuisong@huawei.com>]

在 2023/5/26 20:39, Ard Biesheuvel 写道:
> (cc Lorenzo)
>
> On Fri, 26 May 2023 at 14:20, Huisong Li <lihuisong@huawei.com> 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@huawei.com/

>
> 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@huawei.com>
>> ---
>>   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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> .