Re: [PATCH RFC 3/4] io-128-nonatomic: introduce io{read|write}128_{lo_hi|hi_lo}

[huangchenghai <huangchenghai2@huawei.com>]

在 2025/11/12 22:48, Ben Dooks 写道:
> On 12/11/2025 01:58, Chenghai Huang wrote:
>> From: Weili Qian <qianweili@huawei.com>
>>
>> In order to provide non-atomic functions for io{read|write}128.
>> We define a number of variants of these functions in the generic
>> iomap that will do non-atomic operations.
>>
>> These functions are only defined if io{read|write}128 are defined.
>> If they are not, then the wrappers that always use non-atomic operations
>> from include/linux/io-128-nonatomic*.h will be used.
>>
>> Signed-off-by: Weili Qian <qianweili@huawei.com>
>> Signed-off-by: Chenghai Huang <huangchenghai2@huawei.com>
>> ---
>>   include/linux/io-128-nonatomic-hi-lo.h | 35 ++++++++++++++++++++++++++
>>   include/linux/io-128-nonatomic-lo-hi.h | 34 +++++++++++++++++++++++++
>>   2 files changed, 69 insertions(+)
>>   create mode 100644 include/linux/io-128-nonatomic-hi-lo.h
>>   create mode 100644 include/linux/io-128-nonatomic-lo-hi.h
>>
>> diff --git a/include/linux/io-128-nonatomic-hi-lo.h 
>> b/include/linux/io-128-nonatomic-hi-lo.h
>> new file mode 100644
>> index 000000000000..b5b083a9e81b
>> --- /dev/null
>> +++ b/include/linux/io-128-nonatomic-hi-lo.h
>> @@ -0,0 +1,35 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef _LINUX_IO_128_NONATOMIC_HI_LO_H_
>> +#define _LINUX_IO_128_NONATOMIC_HI_LO_H_
>> +
>> +#include <linux/io.h>
>> +#include <asm-generic/int-ll64.h>
>> +
>> +static inline u128 ioread128_hi_lo(const void __iomem *addr)
>> +{
>> +    u32 low, high;
>
> did you mean u64 here?
>
Thank you for your reminder, I made a rookie mistake.


Chenghai

>> +    high = ioread64(addr + sizeof(u64));
>> +    low = ioread64(addr);
>> +
>> +    return low + ((u128)high << 64);
>> +}
>> +
>> +static inline void iowrite128_hi_lo(u128 val, void __iomem *addr)
>> +{
>> +    iowrite64(val >> 64, addr + sizeof(u64));
>> +    iowrite64(val, addr);
>> +}
>> +
>