The introduction of reference counting on the state structures caused
sanitize_watermarks() in i915 to break in the error handling case,
as pointed out by gcc -Wmaybe-uninitialized

drivers/gpu/drm/i915/intel_display.c: In function ‘intel_modeset_init’:
include/drm/drm_atomic.h:224:2: error: ‘state’ may be used uninitialized in this function [-Werror=maybe-uninitialized]

This changes the function back to only drop the reference count
when it was successfully allocated first.

Fixes: 0853695c ("drm: Add reference counting to drm_atomic_state")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NEric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161018151652.2690201-1-arnd@arndb.de

The function is only used by the drm_helper_mode_fill_fb_struct() core
function to fill the drm_framebuffer bpp and depth fields, used by
drivers that haven't been converted to use pixel formats directly yet.
It should not be used by new drivers, so inline it in its only caller.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-14-git-send-email-laurent.pinchart@ideasonboard.com

The driver doesn't need the color depth, only the number of bits per
pixel. Use the right API.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-13-git-send-email-laurent.pinchart@ideasonboard.com

The driver is the last users of the drm_fb_get_bpp_depth() function. It
should ideally be converted to use struct drm_mode_fb_cmd2 instead of
the legacy struct drm_mode_fb_cmd internally, but that will require
broad changes across the code base. As a first step, replace
drm_fb_get_bpp_depth() with drm_format_info() in order to stop exporting
the function to drivers.

The new DRM_ERROR() message comes from the vmw_create_dmabuf_proxy(),
vmw_kms_new_framebuffer_surface() and vmw_kms_new_framebuffer_dmabuf()
functions that currently print an error if the pixel format is
unsupported.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NSinclair Yeh <syeh@vmware.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-12-git-send-email-laurent.pinchart@ideasonboard.com

The driver needs the number of bytes per pixel, not the bpp and depth
info meant for fbdev compatibility. Use the right API.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-11-git-send-email-laurent.pinchart@ideasonboard.com

The driver needs the number of bytes per pixel, not the bpp and depth
info meant for fbdev compatibility. Use the right API.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-10-git-send-email-laurent.pinchart@ideasonboard.com

The driver uses drm_fb_get_bpp_depth() to check whether it can support
the format requested by userspace when creating a framebuffer. This
isn't the right API, as it doesn't differentiate between RGB formats
other than on a depth and bpp basis.

Fixing this requires non trivial changes to the drivers internals. As a
first step, replace usage of the drm_fb_get_bpp_depth() function with an
equivalent check based on drm_format_info(). This is part of a wider
effort to remove usage of the drm_fb_get_bpp_depth() function in
drivers.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-9-git-send-email-laurent.pinchart@ideasonboard.com

The driver doesn't need the color depth, only the number of bits per
pixel. Use the right API.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-8-git-send-email-laurent.pinchart@ideasonboard.com

The driver needs the number of bytes per pixel, not the bpp and depth
info meant for fbdev compatibility. Use the right API.

In the tilcdc_crtc_mode_set() function compute the hardware register
value directly from the pixel format instead of computing the number of
bits per pixels first.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-7-git-send-email-laurent.pinchart@ideasonboard.com

The driver needs the number of bytes per pixel, not the bpp and depth
info meant for fbdev compatibility. Use the right API.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-6-git-send-email-laurent.pinchart@ideasonboard.com

The format helpers have historically treated unsupported formats as part
of the default case, returning values that are likely wrong. We can't
change this behaviour now without risking breaking drivers in difficult
to detect ways, but we can WARN on unsupported formats to catch faulty
callers.

The only exception is the framebuffer_check() function that calls
drm_format_info() to validate the format passed from userspace. This is
a valid use case that shouldn't generate a warning.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-5-git-send-email-laurent.pinchart@ideasonboard.com

Replace calls to the drm_format_*() helper functions with direct use of
the drm_format_info structure. This improves efficiency by removing
duplicate lookups.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NEric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-4-git-send-email-laurent.pinchart@ideasonboard.com

Turn the drm_format_*() helpers into wrappers around the drm_format_info
lookup function to centralize all format information in a single place.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NEric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-3-git-send-email-laurent.pinchart@ideasonboard.com

Various pieces of information about DRM formats (number of planes, color
depth, chroma subsampling, ...) are scattered across different helper
functions in the DRM core. Callers of those functions often need to
access more than a single parameter of the format, leading to
inefficiencies due to multiple lookups.

Centralize all format information in a data structure and create a
function to look up information based on the format 4CC.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NEric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1476744081-24485-2-git-send-email-laurent.pinchart@ideasonboard.com

gcc warns about the timestamp in drm_wait_vblank being possibly
used without an initialization:

drivers/gpu/drm/drm_irq.c: In function 'drm_crtc_send_vblank_event':
drivers/gpu/drm/drm_irq.c:992:24: error: 'now.tv_usec' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/gpu/drm/drm_irq.c:1069:17: note: 'now.tv_usec' was declared here
drivers/gpu/drm/drm_irq.c:991:23: error: 'now.tv_sec' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This can happen if drm_vblank_count_and_time() returns 0 in its
error path. To sanitize the error case, I'm changing that function
to return a zero timestamp when it fails.

Fixes: e6ae8687 ("drm: idiot-proof vblank")
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161017221355.1861551-6-arnd@arndb.de

Adds files and directories to debugfs for controlling and reading frame
CRCs, per CRTC:

dri/0/crtc-0/crc
dri/0/crtc-0/crc/control
dri/0/crtc-0/crc/data

Drivers can implement the set_crc_source callback() in drm_crtc_funcs to
start and stop generating frame CRCs and can add entries to the output
by calling drm_crtc_add_crc_entry.

v2:
    - Lots of good fixes suggested by Thierry.
    - Added documentation.
    - Changed the debugfs layout.
    - Moved to allocate the entries circular queue once when frame
      generation gets enabled for the first time.
v3:
    - Use the control file just to select the source, and start and stop
      capture when the data file is opened and closed, respectively.
    - Make variable the number of CRC values per entry, per source.
    - Allocate entries queue each time we start capturing as now there
      isn't a fixed number of CRC values per entry.
    - Store the frame counter in the data file as a 8-digit hex number.
    - For sources that cannot provide useful frame numbers, place
      XXXXXXXX in the frame field.

v4:
    - Build only if CONFIG_DEBUG_FS is enabled.
    - Use memdup_user_nul.
    - Consolidate calculation of the size of an entry in a helper.
    - Add 0x prefix to hex numbers in the data file.
    - Remove unnecessary snprintf and strlen usage in read callback.

v5:
    - Made the crcs array in drm_crtc_crc_entry fixed-size
    - Lots of other smaller improvements suggested by Emil Velikov

v7:
    - Move definition of drm_debugfs_crtc_crc_add to drm_internal.h

v8:
    - Call debugfs_remove_recursive when we fail to create the minor
      device

v9:
    - Register the debugfs directory for a crtc from
      drm_crtc_register_all()

v10:
    - Don't let debugfs failures interrupt CRTC registration (Emil
      Velikov)

v11:
    - Remove extra brace that broke compilation. Sorry!
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NEmil Velikov <emil.velikov@collabora.com>
Acked-by: NBenjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1475767268-14379-3-git-send-email-tomeu.vizoso@collabora.com

The current fbdev emulation does not allow to push back changes in
width, height or depth to KMS, hence reject any changes with an
error. This makes sure that fbdev ioctl's fail properly and user
space does not assume that changes succeeded.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Reviewed-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161011231504.17688-1-stefan@agner.ch

Now that we have the name "block" free once more, we can use it to point
to the start of a block within the edid.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161017083514.21772-2-chris@chris-wilson.co.uk

The "block" variable points to the entire edid, not individual blocks
despite it being named such.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161017083514.21772-1-chris@chris-wilson.co.uk

HDMI 2.0/CEA-861-F introduces two new aspect ratios:
- 64:27
- 256:135

This patch:
-  Adds new DRM flags for to represent these new aspect ratios.
-  Adds new cases to handle these aspect ratios while converting
from user->kernel mode or vise versa.

V2: Rebase
V3: Align macro for DRM_MODE_PICTURE_ASPECT_256_135 (Jim Bride)
V4: Added r-b from Jose.
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Reviewed-by: NJose Abreu <Jose.Abreu@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476705880-15600-5-git-send-email-shashank.sharma@intel.com

HDMI 2.0/CEA-861-F introduces two new aspect ratios:
- 64:27
- 256:135

This patch adds enumeration for the new aspect ratios
in the existing aspect ratio list.

V2: rebase
V3: rebase
V4: Added r-b from Jose, Ack by Tomi
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Reviewed-by: NJose Abreu <Jose.Abreu@synopsys.com>
Acked-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476705880-15600-4-git-send-email-shashank.sharma@intel.com

Current DRM layer functions don't parse aspect ratio information
while converting a user mode->kernel mode or vice versa. This
causes modeset to pick mode with wrong aspect ratio, eventually
causing failures in HDMI compliance test cases, due to wrong VIC.

This patch adds aspect ratio information in DRM's mode conversion
and mode comparision functions, to make sure kernel picks mode
with right aspect ratio (as per the VIC).

V2: Addressed review comments from Sean:
- Fix spellings/typo
- No need to handle aspect ratio none
- Add a break, for default case too
V3: Rebase
V4: Added r-b from Jose
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Signed-off-by: NLin, Jia <lin.a.jia@intel.com>
Signed-off-by: NAkashdeep Sharma <akashdeep.sharma@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Reviewed-by: NJose Abreu <Jose.Abreu@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476705880-15600-3-git-send-email-shashank.sharma@intel.com

This patch adds drm flag bits for aspect ratio information

Currently drm flag bits don't have field for mode's picture
aspect ratio. This field will help the driver to pick mode with
right aspect ratio, and help in setting right VIC field in avi
infoframes.

V2: Addressed review comments from Sean
- Changed PAR-> PIC_AR
V3: Rebase
V3: Added r-b by Jose
Signed-off-by: NShashank Sharma <shashank.sharma@intel.com>
Reviewed-by: NJim Bride <jim.bride@linux.intel.com>
Reviewed-by: NJose Abreu <Jose.Abreu@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476705880-15600-2-git-send-email-shashank.sharma@intel.com

Size of kmalloc() in vga_arb_write() is controlled by user.
Too large kmalloc() size triggers WARNING message on console.
Allocate the buffer on stack to avoid the WARNING.
The string must be small (e.g "target PCI:domain:bus:dev.fn").
Signed-off-by: NDmitry Vyukov <dvyukov@google.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: syzkaller@googlegroups.com
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476451342-146510-1-git-send-email-dvyukov@google.com

drm_atomic_state has a complicated single owner model that tracks the
single reference from allocation through to destruction on another
thread - or perhaps on a local error path. We can simplify this tracking
by using reference counting (at a cost of a few more atomics). This is
even more beneficial when the lifetime of the state becomes more
convoluted than being passed to a single worker thread for the commit.

v2: Double check !intel atomic_commit functions for missing gets
v3: Update kerneldocs
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: NEric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161014121833.439-27-chris@chris-wilson.co.uk

Now that drm_crtc_index takes a const, the same can be done for drm_crtc_mask.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/6e32d013-6fee-34ad-f8d2-59139f3dc4c1@linux.intel.com

Add some additional comments to more explicitly describe the meaning and
usage of the three CRTC modeset detection booleans: mode_changed,
connectors_changed and active_changed.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NBrian Starkey <brian.starkey@arm.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476352028-16701-1-git-send-email-brian.starkey@arm.com

A recent cleanup changed the kmalloc() + copy_from_user() to
memdup_user() but the error handling wasn't updated so we might call
kfree(-EFAULT) and crash.

Fixes: a6e3918b ('GPU-DRM-Savage: Use memdup_user() rather than duplicating')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161012062227.GU12841@mwanda

Added comments for new parameters.
Signed-off-by: NJiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476238699-25820-1-git-send-email-jiang.biao2@zte.com.cn

Remove useless comment in framebuffer.c.
Signed-off-by: NJiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476165825-12137-1-git-send-email-jiang.biao2@zte.com.cn

Replace explicit computation of vma page count by a call to
vma_pages()
Signed-off-by: NShyam Saini <mayhs11saini@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476054436-9378-1-git-send-email-mayhs11saini@gmail.com

In order to be completely generic, we have to double check the read
seqlock after acquiring a reference to the fence. If the driver is
allocating fences from a SLAB_DESTROY_BY_RCU, or similar freelist, then
within an RCU grace period a fence may be freed and reallocated. The RCU
read side critical section does not prevent this reallocation, instead
we have to inspect the reservation's seqlock to double check if the
fences have been reassigned as we were acquiring our reference.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-9-chris@chris-wilson.co.uk

In order to be completely generic, we have to double check the read
seqlock after acquiring a reference to the fence. If the driver is
allocating fences from a SLAB_DESTROY_BY_RCU, or similar freelist, then
within an RCU grace period a fence may be freed and reallocated. The RCU
read side critical section does not prevent this reallocation, instead
we have to inspect the reservation's seqlock to double check if the
fences have been reassigned as we were acquiring our reference.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-8-chris@chris-wilson.co.uk

In order to be completely generic, we have to double check the read
seqlock after acquiring a reference to the fence. If the driver is
allocating fences from a SLAB_DESTROY_BY_RCU, or similar freelist, then
within an RCU grace period a fence may be freed and reallocated. The RCU
read side critical section does not prevent this reallocation, instead
we have to inspect the reservation's seqlock to double check if the
fences have been reassigned as we were acquiring our reference.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-7-chris@chris-wilson.co.uk

This variant of fence_get_rcu() takes an RCU protected pointer to a
fence and carefully returns a reference to the fence ensuring that it is
not reallocated as it does. This is required when mixing fences and
SLAB_DESTROY_BY_RCU - although it serves a more pedagogical function atm
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-6-chris@chris-wilson.co.uk

Since fence_wait_timeout_reservation_object_wait_timeout_rcu() with a
timeout of 0 becomes reservation_object_test_signaled_rcu(), we do not
need to handle such conversion in the caller. The only challenge are
those callers that wish to differentiate the error code between the
nonblocking busy check and potentially blocking wait.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: NSinclair Yeh <syeh@vmware.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-5-chris@chris-wilson.co.uk

Since fence_wait_timeout_reservation_object_wait_timeout_rcu() with a
timeout of 0 becomes reservation_object_test_signaled_rcu(), we do not
need to handle such conversion in the caller. The only challenge are
those callers that wish to differentiate the error code between the
nonblocking busy check and potentially blocking wait.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-4-chris@chris-wilson.co.uk

Since fence_wait_timeout_reservation_object_wait_timeout_rcu() with a
timeout of 0 becomes reservation_object_test_signaled_rcu(), we do not
need to handle such conversion in the caller. The only challenge are
those callers that wish to differentiate the error code between the
nonblocking busy check and potentially blocking wait.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Russell King <linux+etnaviv@armlinux.org.uk>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-2-chris@chris-wilson.co.uk

Since fence_wait_timeout_reservation_object_wait_timeout_rcu() with a
timeout of 0 becomes reservation_object_test_signaled_rcu(), we do not
need to handle such conversion in the caller. The only challenge are
those callers that wish to differentiate the error code between the
nonblocking busy check and potentially blocking wait.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20160829070834.22296-1-chris@chris-wilson.co.uk

Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1476113170-13816-1-git-send-email-jani.nikula@intel.com