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

From: Simon Horman
Date: Sun Feb 04 2024 - 05:21:05 EST


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 <njavali@xxxxxxxxxxx>
> Signed-off-by: Chris Leech <cleech@xxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>

..

> 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.

..