[PATCH 01/11] lib: Import iomem_copy from Linux Kernel

[Peng Fan]

On Mon, Oct 13, 2025 at 11:41:25PM +0530, Kumar, Udit wrote:
>
>On 10/13/2025 8:19 AM, Peng Fan (OSS) wrote:
>> From: Peng Fan <peng.fan at nxp.com>
>> 
>> memcpy_{from,to}io and memset_io is needed for i.MX8M to write
>> TCM area. So import the APIs from Linux Kernel 6.17.
>> 
>> Reviewed-by: Ye Li <ye.li at nxp.com>
>> Signed-off-by: Peng Fan <peng.fan at nxp.com>
>> ---
>>   include/asm-generic/io.h |  37 +++++++++++++
>>   lib/Makefile             |   1 +
>>   lib/iomem_copy.c         | 136 +++++++++++++++++++++++++++++++++++++++++++++++
>
>>   3 files changed, 174 insertions(+)
>> 
>> diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
>> index 13d99cfb5973399209c00adee0080ff83414c064..cf981ad3501f935c714b7580536540e7aba249c1 100644
>> --- a/include/asm-generic/io.h
>> +++ b/include/asm-generic/io.h
>> @@ -3,6 +3,7 @@
>>    * Generic I/O functions.
>>    *
>>    * Copyright (c) 2016 Imagination Technologies Ltd.
>> + * Copyright 2025 NXP
>>    */
>>   #ifndef __ASM_GENERIC_IO_H__
>> @@ -453,5 +454,41 @@ static inline void iowrite64_rep(volatile void __iomem *addr,
>>   #endif
>>   #endif /* CONFIG_64BIT */
>> +#ifndef memset_io
>
>If you are on arm, then
>
>arch/arm/include/asm/io.h defines these io functions, for ARM64 and non-ARM64
>platform,
>
>In your SOC, how this works.

Thanks for pointing this out, I thought these helpers were not defined,
so I import this file from Linux. So on my platform, the arm64 io helpers
are used, the functions in this file are not used because there is
"#ifndef xx".

But anyway, for non-ARM/ARM64 platforms, this file is still useful.

I could drop this if you prefer. Or keep this for other ARCH. 

Thanks
Peng

>
>> +/**
>> + * memset_io -	Set a range of I/O memory to a constant value
>> + * @addr:	The beginning of the I/O-memory range to set
>> + * @val:	The value to set the memory to
>> + * @count:	The number of bytes to set
>> + *
>> + * Set a range of I/O memory to a given value.
>> + */
>> +void memset_io(volatile void __iomem *addr, int val, size_t count);
>> +#endif
>> +
>> +#ifndef memcpy_fromio
>> +/**
>> [..]
>