Subject: Re: [PATCH v5 1/4] uio: introduce UIO_MEM_DMA_COHERENT type

From: Simon Horman <[email-masked]>
Date: Sun, 4 Feb 2024 10:20:50 +0000

On Thu, Feb 01, 2024 at 03:33:57PM -0800, Chris Leech wrote:
> Add a UIO memtype specifically for sharing dma_alloc_coherent
> memory with userspace, backed by dma_mmap_coherent.
> 
> This is mainly for the bnx2/bnx2x/bnx2i "cnic" interface, although there
> are a few other uio drivers which map dma_alloc_coherent memory and will
> be converted to use dma_mmap_coherent as well.
> 
> Signed-off-by: Nilesh Javali <[email-masked]>
> Signed-off-by: Chris Leech <[email-masked]>
> Reviewed-by: Christoph Hellwig <[email-masked]>

...

> diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
> index 47c5962b876b0..a7756f909dd01 100644
> --- a/include/linux/uio_driver.h
> +++ b/include/linux/uio_driver.h
> @@ -37,10 +37,12 @@ struct uio_map;
>  struct uio_mem {
>  	const char		*name;
>  	phys_addr_t		addr;
> +	dma_addr_t		dma_addr;
>  	unsigned long		offs;
>  	resource_size_t		size;
>  	int			memtype;
>  	void __iomem		*internal_addr;
> +	struct device		*dma_device;
>  	struct uio_map		*map;
>  };

Hi Chris,

please consider adding these new fields to the kernel doc for this
structure, which appears just above in uio_driver.h.

...