Commit Graph

6 Commits

Author SHA1 Message Date
Jérôme Pouiller 7c3e9fcad9 dma-buf: fix use of DMA_BUF_SET_NAME_{A,B} in userspace
The typedefs u32 and u64 are not available in userspace. Thus user get
an error he try to use DMA_BUF_SET_NAME_A or DMA_BUF_SET_NAME_B:

    $ gcc -Wall   -c -MMD -c -o ioctls_list.o ioctls_list.c
    In file included from /usr/include/x86_64-linux-gnu/asm/ioctl.h:1,
                     from /usr/include/linux/ioctl.h:5,
                     from /usr/include/asm-generic/ioctls.h:5,
                     from ioctls_list.c:11:
    ioctls_list.c:463:29: error: ‘u32’ undeclared here (not in a function)
      463 |     { "DMA_BUF_SET_NAME_A", DMA_BUF_SET_NAME_A, -1, -1 }, // linux/dma-buf.h
          |                             ^~~~~~~~~~~~~~~~~~
    ioctls_list.c:464:29: error: ‘u64’ undeclared here (not in a function)
      464 |     { "DMA_BUF_SET_NAME_B", DMA_BUF_SET_NAME_B, -1, -1 }, // linux/dma-buf.h
          |                             ^~~~~~~~~~~~~~~~~~

The issue was initially reported here[1].

[1]: https://github.com/jerome-pouiller/ioctl/pull/14

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Fixes: a5bff92eaa ("dma-buf: Fix SET_NAME ioctl uapi")
CC: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20220517072708.245265-1-Jerome.Pouiller@silabs.com
Signed-off-by: Christian König <christian.koenig@amd.com>
2022-05-17 13:05:19 +02:00
Jason Ekstrand 51f52547df dma-buf: Document DMA_BUF_IOCTL_SYNC (v3)
This adds a new "DMA Buffer ioctls" section to the dma-buf docs and adds
documentation for DMA_BUF_IOCTL_SYNC.

v2 (Daniel Vetter):
 - Fix a couple typos
 - Add commentary about synchronization with other devices
 - Use item list format for describing flags

v3 (Pekka Paalanen):
 - Clarify stalling requirements.
 - Be more clear that that DMA_BUF_IOCTL_SYNC with SINC_END has to be
   called before more GPU work happens.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210617194258.579011-1-jason@jlekstrand.net
2021-06-17 21:46:37 +02:00
Daniel Vetter a5bff92eaa dma-buf: Fix SET_NAME ioctl uapi
The uapi is the same on 32 and 64 bit, but the number isn't. Everyone
who botched this please re-read:

https://www.kernel.org/doc/html/v5.4-preprc-cpu/ioctl/botching-up-ioctls.html

Also, the type argument for the ioctl macros is for the type the void
__user *arg pointer points at, which in this case would be the
variable-sized char[] of a 0 terminated string. So this was botched in
more than just the usual ways.

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: minchan@kernel.org
Cc: surenb@google.com
Cc: jenhaochen@google.com
Cc: Martin Liu <liumartin@google.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Tested-by: Martin Liu <liumartin@google.com>
Reviewed-by: Martin Liu <liumartin@google.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
  [sumits: updated some checkpatch fixes, corrected author email]
Link: https://patchwork.freedesktop.org/patch/msgid/20200407133002.3486387-1-daniel.vetter@ffwll.ch
2020-04-27 16:29:41 +05:30
Greg Hackmann bb2bb90304 dma-buf: add DMA_BUF_SET_NAME ioctls
This patch adds complimentary DMA_BUF_SET_NAME  ioctls, which lets
userspace processes attach a free-form name to each buffer.

This information can be extremely helpful for tracking and accounting
shared buffers.  For example, on Android, we know what each buffer will
be used for at allocation time: GL, multimedia, camera, etc.  The
userspace allocator can use DMA_BUF_SET_NAME to associate that
information with the buffer, so we can later give developers a
breakdown of how much memory they're allocating for graphics, camera,
etc.

Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Chenbo Feng <fengc@google.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190613223408.139221-3-fengc@google.com
2019-06-14 15:00:51 +05:30
Greg Kroah-Hartman e2be04c7f9 License cleanup: add SPDX license identifier to uapi header files with a license
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be.  This makes it hard for
compliance tools to determine the correct license.

Update these files with an SPDX license identifier.  The identifier was
chosen based on the license information in the file.

GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.

Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier.  The format
is:
        ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)

SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text.  The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:20:11 +01:00
Daniel Vetter c11e391da2 dma-buf: Add ioctls to allow userspace to flush
The userspace might need some sort of cache coherency management e.g. when CPU
and GPU domains are being accessed through dma-buf at the same time. To
circumvent this problem there are begin/end coherency markers, that forward
directly to existing dma-buf device drivers vfunc hooks. Userspace can make use
of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The sequence would be
used like following:
     - mmap dma-buf fd
     - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write
       to mmap area 3. SYNC_END ioctl. This can be repeated as often as you
       want (with the new data being consumed by the GPU or say scanout device)
     - munmap once you don't need the buffer any more

v2 (Tiago): Fix header file type names (u64 -> __u64)
v3 (Tiago): Add documentation. Use enum dma_buf_sync_flags to the begin/end
dma-buf functions. Check for overflows in start/length.
v4 (Tiago): use 2d regions for sync.
v5 (Tiago): forget about 2d regions (v4); use _IOW in DMA_BUF_IOCTL_SYNC and
remove range information from struct dma_buf_sync.
v6 (Tiago): use __u64 structured padded flags instead enum. Adjust
documentation about the recommendation on using sync ioctls.
v7 (Tiago): Alex' nit on flags definition and being even more wording in the
doc about sync usage.
v9 (Tiago): remove useless is_dma_buf_file check. Fix sync.flags conditionals
and its mask order check. Add <linux/types.h> include in dma-buf.h.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Tiago Vignatti <tiago.vignatti@intel.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455228291-29640-1-git-send-email-tiago.vignatti@intel.com
2016-02-12 16:01:32 +01:00