Commit Graph

17 Commits

Author SHA1 Message Date
Mathias Krause bd3e22088f dma-buf: remove dma_buf_debugfs_create_file()
There is only a single user of dma_buf_debugfs_create_file() and that
one got the function pointer cast wrong. With that one fixed, there is
no need to have a wrapper for debugfs_create_file(), just call it
directly.

With no users left, we can remove dma_buf_debugfs_create_file().

While at it, simplify the error handling in dma_buf_init_debugfs()
slightly.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1466339491-12639-2-git-send-email-minipli@googlemail.com
2016-06-20 22:26:37 +05:30
Mathias Krause b747999043 dma-buf: remove dma_buf directory on bufinfo file creation errors
Change the error handling in dma_buf_init_debugfs() to remove the
"dma_buf" directory if creating the "bufinfo" file fails. No need to
have an empty debugfs directory around.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2016-06-20 22:26:36 +05:30
Mathias Krause eb0b947e3b dma-buf: propagate errors from dma_buf_describe() on debugfs read
The callback function dma_buf_describe() returns an int not void so the
function pointer cast in dma_buf_show() is wrong. dma_buf_describe() can
also fail when acquiring the mutex gets interrupted so always returning
0 in dma_buf_show() is wrong, too.

Fix both issues by avoiding the indirection via dma_buf_show() and call
dma_buf_describe() directly. Rename it to dma_buf_debug_show() to get it
in line with the other functions.

This type mismatch was caught by the PaX RAP plugin.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: PaX Team <pageexec@freemail.hu>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2016-06-20 22:26:36 +05:30
Muhammad Falak R Wani b02da6f823 dma-buf: use vma_pages()
Replace explicit computation of vma page count by a call to
vma_pages().
Also, include <linux/mm.h>

Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2016-05-31 22:17:05 +05:30
Daniel Vetter 87e332d56b dma-buf: Update docs for SYNC ioctl
Just a bit of wording polish plus mentioning that it can fail and must
be restarted.

Requested by Sumit.

v2: Fix them typos (Hans).

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tiago Vignatti <tiago.vignatti@intel.com>
Cc: Stéphane Marchesin <marcheu@chromium.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
CC: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: intel-gfx@lists.freedesktop.org
Cc: devel@driverdev.osuosl.org
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2016-03-21 09:26:45 +01:00
Chris Wilson 18b862dcd5 dma-buf, drm, ion: Propagate error code from dma_buf_start_cpu_access()
Drivers, especially i915.ko, can fail during the initial migration of a
dma-buf for CPU access. However, the error code from the driver was not
being propagated back to ioctl and so userspace was blissfully ignorant
of the failure. Rendering corruption ensues.

Whilst fixing the ioctl to return the error code from
dma_buf_start_cpu_access(), also do the same for
dma_buf_end_cpu_access().  For most drivers, dma_buf_end_cpu_access()
cannot fail. i915.ko however, as most drivers would, wants to avoid being
uninterruptible (as would be required to guarrantee no failure when
flushing the buffer to the device). As userspace already has to handle
errors from the SYNC_IOCTL, take advantage of this to be able to restart
the syscall across signals.

This fixes a coherency issue for i915.ko as well as reducing the
uninterruptible hold upon its BKL, the struct_mutex.

Fixes commit c11e391da2
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Feb 11 20:04:51 2016 -0200

    dma-buf: Add ioctls to allow userspace to flush

Testcase: igt/gem_concurrent_blit/*dmabuf*interruptible
Testcase: igt/prime_mmap_coherency/ioctl-errors
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tiago Vignatti <tiago.vignatti@intel.com>
Cc: Stéphane Marchesin <marcheu@chromium.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
CC: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: intel-gfx@lists.freedesktop.org
Cc: devel@driverdev.osuosl.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1458331359-2634-1-git-send-email-chris@chris-wilson.co.uk
2016-03-19 11:03:49 +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
Tiago Vignatti 831e9da7dc dma-buf: Remove range-based flush
This patch removes range-based information used for optimizations in
begin_cpu_access and end_cpu_access.

We don't have any user nor implementation using range-based flush. It seems a
consensus that if we ever want something like that again (or even more robust
using 2D, 3D sub-range regions) we can use the upcoming dma-buf sync ioctl for
such.

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Tiago Vignatti <tiago.vignatti@intel.com>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1450820214-12509-3-git-send-email-tiago.vignatti@intel.com
2016-02-09 09:25:22 +01:00
Jagan Teki 5136629dc5 dma-buf: Minor coding style fixes
- WARNING: Missing a blank line after declarations
- WARNING: line over 80 characters
- WARNING: please, no space before tabs

Signed-off-by: Jagan Teki <jteki@openedev.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2015-05-21 11:29:59 +05:30
Sumit Semwal 9abdffe286 dma-buf: add ref counting for module as exporter
Add reference counting on a kernel module that exports dma-buf and
implements its operations. This prevents the module from being unloaded
while DMABUF file is in use.

The original patch [1] was submitted by Tomasz Stanislawski, but this
is a simpler way to do it.

v3: call module_put() as late as possible, per gregkh's comment.
v2: move owner to struct dma_buf, and use DEFINE_DMA_BUF_EXPORT_INFO
    macro to simplify the change.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>

[1]: https://lkml.org/lkml/2012/8/8/163
2015-05-13 14:35:57 +05:30
Sumit Semwal d8fbe341be dma-buf: cleanup dma_buf_export() to make it easily extensible
At present, dma_buf_export() takes a series of parameters, which
makes it difficult to add any new parameters for exporters, if required.

Make it simpler by moving all these parameters into a struct, and pass
the struct * as parameter to dma_buf_export().

While at it, unite dma_buf_export_named() with dma_buf_export(), and
change all callers accordingly.

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2015-04-21 14:47:16 +05:30
Al Viro a1f6dbac62 dma-buf: don't open-code atomic_long_read()
... not to mention that even atomic_long_read() is too low-level here -
there's file_count().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:39:07 -04:00
Maarten Lankhorst 3c3b177a93 reservation: add suppport for read-only access using rcu
This adds some extra functions to deal with rcu.

reservation_object_get_fences_rcu() will obtain the list of shared
and exclusive fences without obtaining the ww_mutex.

reservation_object_wait_timeout_rcu() will wait on all fences of the
reservation_object, without obtaining the ww_mutex.

reservation_object_test_signaled_rcu() will test if all fences of the
reservation_object are signaled without using the ww_mutex.

reservation_object_get_excl and reservation_object_get_list require
the reservation object to be held, updating requires
write_seqcount_begin/end. If only the exclusive fence is needed,
rcu_dereference followed by fence_get_rcu can be used, if the shared
fences are needed it's recommended to use the supplied functions.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Reviewed-By: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-08 13:41:08 -07:00
Maarten Lankhorst 04a5faa8cb reservation: update api and add some helpers
Move the list of shared fences to a struct, and return it in
reservation_object_get_list().
Add reservation_object_get_excl to get the exclusive fence.

Add reservation_object_reserve_shared(), which reserves space
in the reservation_object for 1 more shared fence.

reservation_object_add_shared_fence() and
reservation_object_add_excl_fence() are used to assign a new
fence to a reservation_object pointer, to complete a reservation.

Changes since v1:
- Add reservation_object_get_excl, reorder code a bit.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-08 13:37:35 -07:00
Maarten Lankhorst 9b495a5887 dma-buf: add poll support, v3
Thanks to Fengguang Wu for spotting a missing static cast.

v2:
- Kill unused variable need_shared.
v3:
- Clarify the BUG() in dma_buf_release some more. (Rob Clark)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-08 13:36:52 -07:00
Maarten Lankhorst 3aac4502fd dma-buf: use reservation objects
This allows reservation objects to be used in dma-buf. it's required
for implementing polling support on the fences that belong to a dma-buf.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Mauro Carvalho Chehab <m.chehab@samsung.com> #drivers/media/v4l2-core/
Acked-by: Thomas Hellstrom <thellstrom@vmware.com> #drivers/gpu/drm/ttm
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net> #drivers/gpu/drm/armada/
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-08 13:03:20 -07:00
Maarten Lankhorst 35fac7e305 dma-buf: move to drivers/dma-buf
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-08 10:51:06 -07:00