linux_dsm_epyc7002/drivers/gpu/drm
Chris Wilson 77ae995789 drm/i915: Enable userspace to opt-out of implicit fencing
Userspace is faced with a dilemma. The kernel requires implicit fencing
to manage resource usage (we always must wait for the GPU to finish
before releasing its PTE) and for third parties. However, userspace may
wish to avoid this serialisation if it is either using explicit fencing
between parties and wants more fine-grained access to buffers (e.g. it
may partition the buffer between uses and track fences on ranges rather
than the implicit fences tracking the whole object). It follows that
userspace needs a mechanism to avoid the kernel's serialisation on its
implicit fences before execbuf execution.

The next question is whether this is an object, execbuf or context flag.
Hybrid users (such as using explicit EGL_ANDROID_native_sync fencing on
shared winsys buffers, but implicit fencing on internal surfaces)
require a per-object level flag. Given that this flag need to be only
set once for the lifetime of the object, this reduces the convenience of
having an execbuf or context level flag (and avoids having multiple
pieces of uABI controlling the same feature).

Incorrect use of this flag will result in rendering corruption and GPU
hangs - but will not result in use-after-free or similar resource
tracking issues.

Serious caveat: write ordering is not strictly correct after setting
this flag on a render target on multiple engines. This affects all
subsequent GEM operations (execbuf, set-domain, pread) and shared
dma-buf operations. A fix is possible - but costly (both in terms of
further ABI changes and runtime overhead).

Testcase: igt/gem_exec_async
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Chad Versace <chadversary@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170127094008.27489-1-chris@chris-wilson.co.uk
2017-01-27 19:55:35 +00:00
..
amd Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
arc drm: bridge: Link encoder and bridge in core code 2016-12-18 16:31:45 +05:30
arm drm: Nuke fb->pixel_format 2016-12-15 14:55:34 +02:00
armada Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
ast Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
atmel-hlcdc drm: bridge: Link encoder and bridge in core code 2016-12-18 16:31:45 +05:30
bochs drm: fix compilations issues introduced by "drm: allow to use mmuless SoC" 2017-01-09 11:30:30 +01:00
bridge drm: bridge: Link encoder and bridge in core code 2016-12-18 16:31:45 +05:30
cirrus drm: fix compilations issues introduced by "drm: allow to use mmuless SoC" 2017-01-09 11:30:30 +01:00
etnaviv Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
exynos Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
fsl-dcu drm: Change the return type of the unload hook to void 2017-01-09 11:25:22 +01:00
gma500 Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
hisilicon drm: fix compilations issues introduced by "drm: allow to use mmuless SoC" 2017-01-09 11:30:30 +01:00
i2c drm/i2c: tda998x: fix spelling mistake 2016-11-18 00:00:40 +00:00
i810
i915 drm/i915: Enable userspace to opt-out of implicit fencing 2017-01-27 19:55:35 +00:00
imx drm/imx: imx-tve: Remove unused variable 2017-01-05 09:44:20 +01:00
lib drm: Add a simple generator of random permutations 2016-12-27 12:34:00 +01:00
mediatek drm: bridge: Link encoder and bridge in core code 2016-12-18 16:31:45 +05:30
meson drm: Nuke fb->pixel_format 2016-12-15 14:55:34 +02:00
mga drm: Change the return type of the unload hook to void 2017-01-09 11:25:22 +01:00
mgag200 drm: fix compilations issues introduced by "drm: allow to use mmuless SoC" 2017-01-09 11:30:30 +01:00
msm Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
mxsfb drm: Nuke fb->pixel_format 2016-12-15 14:55:34 +02:00
nouveau Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
omapdrm Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
panel drm/panel: simple: Add support for AUO G185HAN01 2016-12-06 17:06:32 +01:00
qxl drm: fix compilations issues introduced by "drm: allow to use mmuless SoC" 2017-01-09 11:30:30 +01:00
r128
radeon Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
rcar-du drm: bridge: Link encoder and bridge in core code 2016-12-18 16:31:45 +05:30
rockchip drm: rockchip: use crtc helper drm_crtc_from_index() 2016-12-30 12:15:11 +01:00
savage drm: Change the return type of the unload hook to void 2017-01-09 11:25:22 +01:00
selftests drm/mm: Convert to drm_printer 2016-12-30 12:08:28 +01:00
shmobile drm: Change the return type of the unload hook to void 2017-01-09 11:25:22 +01:00
sis drm: Change the return type of the unload hook to void 2017-01-09 11:25:22 +01:00
sti drm: bridge: Link encoder and bridge in core code 2016-12-18 16:31:45 +05:30
sun4i drm: bridge: Link encoder and bridge in core code 2016-12-18 16:31:45 +05:30
tdfx
tegra Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
tilcdc Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
ttm Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
udl Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
vc4 drm: Don't include <drm/drm_encoder.h> in <drm/drm_crtc.h> 2016-12-18 16:29:29 +05:30
vgem mm: use vmf->address instead of of vmf->virtual_address 2016-12-14 16:04:09 -08:00
via drm: Change the return type of the unload hook to void 2017-01-09 11:25:22 +01:00
virtio Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-01-10 08:06:56 +10:00
vmwgfx drm: fix compilations issues introduced by "drm: allow to use mmuless SoC" 2017-01-09 11:30:30 +01:00
zte drm: zte: use crtc helper drm_crtc_from_index() 2016-12-30 12:15:01 +01:00
ati_pcigart.c
drm_agpsupport.c
drm_atomic_helper.c drm: reference count event->completion 2017-01-04 11:03:06 +01:00
drm_atomic.c drm: Add kernel-doc for drm_crtc_commit_get/put 2017-01-05 08:55:02 +01:00
drm_auth.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_blend.c
drm_bridge.c drm/bridge: Use recommened kerneldoc for struct member refs 2017-01-02 09:17:26 +01:00
drm_bufs.c
drm_cache.c
drm_color_mgmt.c Revert "drm/color: un-inline drm_color_lut_extract()" 2017-01-27 16:15:06 +02:00
drm_connector.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_context.c
drm_crtc_helper_internal.h
drm_crtc_helper.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_crtc_internal.h drm: Move atomic debugfs functions into drm_crtc_internal.h 2016-12-18 14:18:12 +01:00
drm_crtc.c drm: add more document for drm_crtc_from_index() 2017-01-09 11:24:16 +01:00
drm_debugfs_crc.c drm: crc: Call wake_up_interruptible() each time there is a new CRC entry 2017-01-06 15:23:19 +01:00
drm_debugfs.c drm: Move atomic debugfs functions into drm_crtc_internal.h 2016-12-18 14:18:12 +01:00
drm_dma.c
drm_dp_aux_dev.c
drm_dp_dual_mode_helper.c
drm_dp_helper.c
drm_dp_mst_topology.c
drm_drv.c drm: Avoid NULL dereference of drm_device.dev 2016-12-30 15:29:44 +01:00
drm_dumb_buffers.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_edid_load.c
drm_edid.c drm/edid: constify edid quirk list 2017-01-02 15:06:39 +02:00
drm_encoder_slave.c
drm_encoder.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_fb_cma_helper.c drm/cma-helpers: Use recommened kerneldoc for struct member refs 2016-12-30 17:58:15 +01:00
drm_fb_helper.c drm: remove useless parameters from drm_pick_cmdline_mode function 2017-01-09 11:18:41 +01:00
drm_flip_work.c
drm_fops.c drm: reference count event->completion 2017-01-04 11:03:06 +01:00
drm_fourcc.c drm: move allocation out of drm_get_format_name() 2016-11-12 14:19:38 +01:00
drm_framebuffer.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_gem_cma_helper.c drm: allow to use mmuless SoC 2017-01-06 11:04:54 +01:00
drm_gem.c
drm_global.c drm: Update TTM initialization documentation 2016-12-30 12:52:10 +01:00
drm_hashtab.c
drm_info.c
drm_internal.h drm/irq: drm_legacy_ prefix for legacy ioctls 2016-12-18 14:18:12 +01:00
drm_ioc32.c
drm_ioctl.c drm: Export drm_ioctl_permit to kernel-doc 2016-12-30 12:40:48 +01:00
drm_irq.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_kms_helper_common.c
drm_legacy.h drm: compile drm_vm.c only when needed 2017-01-06 11:03:07 +01:00
drm_lock.c drm: Avoid NULL dereference for DRM_LEGACY debug message 2016-11-28 08:39:41 +01:00
drm_memory.c
drm_mipi_dsi.c
drm_mm.c drm/mm: Some doc polish 2016-12-30 12:53:51 +01:00
drm_mode_config.c drm: Clean up connectors by unreferencing them 2016-12-18 14:33:51 +01:00
drm_mode_object.c drm: Get atomic property value even if DRIVER_ATOMIC is not set 2016-12-27 10:44:33 +01:00
drm_modes.c Revert "drm: Add aspect ratio parsing in DRM layer" 2016-11-15 15:01:42 +01:00
drm_modeset_helper.c drm: Convert all helpers to drm_connector_list_iter 2016-12-18 14:33:22 +01:00
drm_modeset_lock.c drm/doc: Fix indenting in drm_modeset_lock.c comment 2016-11-29 23:34:36 +01:00
drm_of.c drm: Don't include <drm/drm_encoder.h> in <drm/drm_crtc.h> 2016-12-18 16:29:29 +05:30
drm_panel.c
drm_pci.c drm: Deduplicate driver initialization message 2016-12-30 12:37:39 +01:00
drm_plane_helper.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_plane.c drm: add more document for drm_crtc_from_index() 2017-01-09 11:24:16 +01:00
drm_platform.c drm: Deduplicate driver initialization message 2016-12-30 12:37:39 +01:00
drm_prime.c drm: Take ownership of the dmabuf->obj when exporting 2016-12-08 10:29:22 +01:00
drm_print.c drm/printer: add debug printer 2016-12-30 11:43:40 +01:00
drm_probe_helper.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_property.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_rect.c drm/rect: Fix formatting of example code 2016-12-30 13:35:54 +01:00
drm_scatter.c
drm_simple_kms_helper.c drm/doc: use preferred struct reference in kernel-doc 2016-12-30 13:34:59 +01:00
drm_sysfs.c
drm_trace_points.c
drm_trace.h
drm_vm.c mm: use vmf->address instead of of vmf->virtual_address 2016-12-14 16:04:09 -08:00
drm_vma_manager.c
Kconfig drm: fix compilations issues introduced by "drm: allow to use mmuless SoC" 2017-01-09 11:30:30 +01:00
Makefile drm: compile drm_vm.c only when needed 2017-01-06 11:03:07 +01:00