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Tvrtko Ursulin 7938d61591 drm/i915: Flush TLBs before releasing backing store
We need to flush TLBs before releasing backing store otherwise userspace
is able to encounter stale entries if a) it is not declaring access to
certain buffers and b) it races with the backing store release from a
such undeclared execution already executing on the GPU in parallel.

The approach taken is to mark any buffer objects which were ever bound
to the GPU and to trigger a serialized TLB flush when their backing
store is released.

Alternatively the flushing could be done on VMA unbind, at which point
we would be able to ascertain whether there is potential a parallel GPU
execution (which could race), but essentially it boils down to paying
the cost of TLB flushes potentially needlessly at VMA unbind time (when
the backing store is not known to be going away so not needed for
safety), versus potentially needlessly at backing store relase time
(since we at that point cannot tell whether there is anything executing
on the GPU which uses that object).

Thereforce simplicity of implementation has been chosen for now with
scope to benchmark and refine later as required.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reported-by: Sushma Venkatesh Reddy <sushma.venkatesh.reddy@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Dave Airlie <airlied@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-25 20:06:06 +02:00
arch ARM fixes for 5.17-rc: 2022-01-25 08:02:46 +02:00
block bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
certs certs: Fix build error when CONFIG_MODULE_SIG_KEY is empty 2022-01-23 00:08:44 +09:00
crypto lib/crypto: add prompts back to crypto libraries 2022-01-18 13:03:55 +01:00
Documentation - A bunch of fixes: forced idle time accounting, utilization values 2022-01-23 17:35:27 +02:00
drivers drm/i915: Flush TLBs before releasing backing store 2022-01-25 20:06:06 +02:00
fs for-5.17-rc1-tag 2022-01-25 18:29:10 +02:00
include - A bunch of fixes: forced idle time accounting, utilization values 2022-01-23 17:35:27 +02:00
init lib/stackdepot: allow optional init and stack_table allocation by kvmalloc() 2022-01-22 08:33:37 +02:00
ipc proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
kernel powerpc fixes for 5.17 #2 2022-01-23 17:52:42 +02:00
lib bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
net bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
samples Merge branch 'akpm' (patches from Andrew) 2022-01-20 10:41:01 +02:00
scripts Devicetree fixes for v5.17, take 1: 2022-01-22 09:52:17 +02:00
security fs.idmapped.v5.17 2022-01-11 14:26:55 -08:00
sound proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
tools powerpc fixes for 5.17 #2 2022-01-23 17:52:42 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-01-22 21:48:45 +09:00
virt Generic: 2022-01-22 09:40:01 +02:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap RISCV: 2022-01-16 16:15:14 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Removing Ohad from remoteproc/rpmsg maintenance 2021-12-08 10:09:40 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
Makefile Linux 5.17-rc1 2022-01-23 10:12:53 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.