linux-kernel - Re: [PATCH v2 13/13] udmabuf: add documentation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <ae4524da-abdb-e5b5-7658-3a0e9a6a071e@infradead.org>
Date:   Tue, 11 Sep 2018 08:40:26 -0700
From:   Randy Dunlap <rdunlap@...radead.org>
To:     Gerd Hoffmann <kraxel@...hat.com>, dri-devel@...ts.freedesktop.org
Cc:     laurent.pinchart@...asonboard.com, daniel@...ll.ch,
        Sumit Semwal <sumit.semwal@...aro.org>,
        Jonathan Corbet <corbet@....net>,
        "open list:DMA BUFFER SHARING FRAMEWORK" 
        <linux-media@...r.kernel.org>,
        "moderated list:DMA BUFFER SHARING FRAMEWORK" 
        <linaro-mm-sig@...ts.linaro.org>,
        "open list:DOCUMENTATION" <linux-doc@...r.kernel.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 13/13] udmabuf: add documentation

On 9/11/18 6:42 AM, Gerd Hoffmann wrote:
> Signed-off-by: Gerd Hoffmann <kraxel@...hat.com>
> ---
>  include/uapi/linux/udmabuf.h         | 50 +++++++++++++++++++++++++++++++++---
>  Documentation/driver-api/dma-buf.rst |  8 ++++++
>  2 files changed, 55 insertions(+), 3 deletions(-)
> 
> diff --git a/include/uapi/linux/udmabuf.h b/include/uapi/linux/udmabuf.h
> index 46b6532ed8..f30b37cb5c 100644
> --- a/include/uapi/linux/udmabuf.h
> +++ b/include/uapi/linux/udmabuf.h
> @@ -5,8 +5,38 @@
>  #include <linux/types.h>
>  #include <linux/ioctl.h>
>  
> +/**
> + * DOC: udmabuf
> + *
> + * udmabuf is a device driver which allows userspace create dmabufs.

                                                        to create

> + * The memory used for these dmabufs must be backed by memfd.  The
> + * memfd must have F_SEAL_SHRINK and it must not have F_SEAL_WRITE.
> + *
> + * The driver has two ioctls, one to create a dmabuf from a single
> + * memory block and one to create a dmabuf from a list of memory
> + * blocks.
> + *
> + * UDMABUF_CREATE - _IOW('u', 0x42, udmabuf_create)
> + *
> + * UDMABUF_CREATE_LIST - _IOW('u', 0x43, udmabuf_create_list)
> + */
> +
> +#define UDMABUF_CREATE       _IOW('u', 0x42, struct udmabuf_create)
> +#define UDMABUF_CREATE_LIST  _IOW('u', 0x43, struct udmabuf_create_list)
> +
>  #define UDMABUF_FLAGS_CLOEXEC	0x01
>  
> +/**
> + * struct udmabuf_create - create a dmabuf from a single memory block.
> + *
> + * @memfd: The file handle.
> + * @offset: Start of the buffer (from memfd start).
> + * Must be page aligned.
> + * @size: Size of the buffer.  Must be rounded to page size.

      @flags: ???

> + *
> + * flags:
> + * UDMABUF_FLAGS_CLOEXEC: set CLOEXEC flag for the dmabuf.
> + */
>  struct udmabuf_create {
>  	__u32 memfd;
>  	__u32 flags;
> @@ -14,6 +44,14 @@ struct udmabuf_create {
>  	__u64 size;
>  };
>  
> +/**
> + * struct udmabuf_create_item - one memory block list item.
> + *
> + * @memfd: The file handle.
> + * @offset: Start of the buffer (from memfd start).
> + * Must be page aligned.
> + * @size: Size of the buffer.  Must be rounded to page size.
> + */
>  struct udmabuf_create_item {
>  	__u32 memfd;
>  	__u32 __pad;
> @@ -21,13 +59,19 @@ struct udmabuf_create_item {
>  	__u64 size;
>  };
>  
> +/**
> + * struct udmabuf_create_list - create a dmabuf from a memory block list.
> + *
> + * @count: The number of list elements.
> + * @list: The memory block list
> + *
> + * flags:

      @flags:

> + * UDMABUF_FLAGS_CLOEXEC: set CLOEXEC flag for the dmabuf.
> + */
>  struct udmabuf_create_list {
>  	__u32 flags;
>  	__u32 count;
>  	struct udmabuf_create_item list[];
>  };


thanks.
-- 
~Randy