Re: [PATCH v2 resend 4/5] arm64: mm: Convert to GENERIC_IOREMAP

[Kefeng Wang <wangkefeng.wang@huawei.com>]

On 2022/5/19 13:34, Anshuman Khandual wrote:
>
> On 5/2/22 08:57, Kefeng Wang wrote:
>> Add hook for arm64's special operation when ioremap() and iounmap(),
>> then ioremap_wc/np/cache is converted to use ioremap_prot()
>> from GENERIC_IOREMAP, update the Copyright and kill the unused
>> inclusions.
>>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>> ---
>> v2 resend:
>> - use IOMEM_ERR_PTR to fix sparse warning found by lkp
>>
>>   arch/arm64/Kconfig          |  1 +
>>   arch/arm64/include/asm/io.h | 20 ++++++---
>>   arch/arm64/kernel/acpi.c    |  2 +-
>>   arch/arm64/mm/ioremap.c     | 85 +++++--------------------------------
>>   4 files changed, 27 insertions(+), 81 deletions(-)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 20ea89d9ac2f..56673209fdb9 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -123,6 +123,7 @@ config ARM64
>>   	select GENERIC_CPU_VULNERABILITIES
>>   	select GENERIC_EARLY_IOREMAP
>>   	select GENERIC_IDLE_POLL_SETUP
>> +	select GENERIC_IOREMAP
>>   	select GENERIC_IRQ_IPI
>>   	select GENERIC_IRQ_PROBE
>>   	select GENERIC_IRQ_SHOW
>> diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
>> index 7fd836bea7eb..042fa01940b8 100644
>> --- a/arch/arm64/include/asm/io.h
>> +++ b/arch/arm64/include/asm/io.h
>> @@ -163,13 +163,21 @@ extern void __memset_io(volatile void __iomem *, int, size_t);
>>   /*
>>    * I/O memory mapping functions.
>>    */
>> -extern void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot);
>> -extern void iounmap(volatile void __iomem *addr);
>> -extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
>>   
>> -#define ioremap(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
>> -#define ioremap_wc(addr, size)		__ioremap((addr), (size), __pgprot(PROT_NORMAL_NC))
>> -#define ioremap_np(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRnE))
>> +void __iomem *arch_ioremap(phys_addr_t phys_addr, size_t size, unsigned long prot);
>> +#define arch_ioremap arch_ioremap
>> +
>> +int arch_iounmap(void __iomem *addr);
>> +#define arch_iounmap arch_iounmap
>> +
>> +#define _PAGE_IOREMAP PROT_DEVICE_nGnRE
> Small nit, should we have a comment here for the above components i.e
> PAGE_IOREMAP and callbacks arch_ioremap()/arch_iounmap() are required
> because of enabling GENERIC_IOREMAP ?

There is a comment in  include/asm-generic/io.h:       /* _PAGE_IOREMAP 
needs to be supplied by the architecture */

so arch's callbacks could not add repeated comments.


> Otherwise LGTM.
>
> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Thanks.
> .