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

[Ben Dooks]

On 12/11/2025 01:58, Chenghai Huang wrote:
> From: Weili Qian <qianweili@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Signed-off-by: Chenghai Huang <huangchenghai2@xxxxxxxxxx>
> ---
>   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?

> +	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);
> +}
> +

--
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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