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Ville Syrjälä 54d4d719fa drm/i915: Overcome display engine stride limits via GTT remapping
The display engine stride limits are getting in our way. On SKL+
we are limited to 8k pixels, which is easily exceeded with three
4k displays. To overcome this limitation we can remap the pages
in the GTT to provide the display engine with a view of memory
with a smaller stride.

The code is mostly already there as We already play tricks with
the plane surface address and x/y offsets.

A few caveats apply:
* linear buffers need the fb stride to be page aligned, as
  otherwise the remapped lines wouldn't start at the same
  spot
* compressed buffers can't be remapped due to the new
  ccs hash mode causing the virtual address of the pages
  to affect the interpretation of the compressed data. IIRC
  the old hash was limited to the low 12 bits so if we were
  using that mode we could remap. As it stands we just refuse
  to remapp with compressed fbs.
* no remapping gen2/3 as we'd need a fence for the remapped
  vma, which we currently don't have. Need to deal with the
  fence POT requirements, and do something about the gen2
  gtt page size vs tile size difference

v2: Rebase due to is_ccs_modifier()
    Fix up the skl+ stride_mult mess
    memset() the gtt_view because otherwise we could leave
    junk in plane[1] when going from 2 plane to 1 plane format
v3: intel_check_plane_stride() was split out
v4: Drop the aligned viewport stuff, it was meant for ccs which
    can't be remapped anyway
v5: Introduce intel_plane_can_remap()
    Reorder the code so that plane_state->view gets filled
    even for invisible planes, otherwise we'd keep using
    stale values and could explode during remapping. The new
    logic never remaps invisible planes since we don't have
    a viewport, and instead pins the full fb instead
v6: Fix plane src coord checks after remapping by moving
    plane_state->base.src to the final plane x/y offsets.
    Allow intel_plane_check_stride() to fail even with
    remapping (can happen at least with a linear 64bpp
    fb with a 4k plane and a suitably inconvenient src
    coordinates).
    Improve aux plane FIXME (Daniel)
    Move some code shuffling into a separate patch (Daniel)

Testcase: igt/kms_big_fb
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190509122159.24376-6-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
2019-05-20 18:04:47 +03:00
arch Merge tag 'drm-intel-next-2019-04-17' of git://anongit.freedesktop.org/drm/drm-intel into drm-next 2019-04-24 10:02:20 +10:00
block block: do not leak memory in bio_copy_user_iov() 2019-04-10 16:14:40 -06:00
certs kexec, KEYS: Make use of platform keyring for signature verify 2019-02-04 17:34:07 -05:00
crypto lib/lzo: separate lzo-rle from lzo 2019-03-07 18:32:03 -08:00
Documentation drm: revocation check at drm subsystem 2019-05-09 09:44:41 +02:00
drivers drm/i915: Overcome display engine stride limits via GTT remapping 2019-05-20 18:04:47 +03:00
fs Merge branch 'page-refs' (page ref overflow) 2019-04-14 15:09:40 -07:00
include drm/i915/icl: More workaround for port F detection due to broken VBTs 2019-05-14 13:46:59 +03:00
init init/main: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
ipc Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-03-12 14:08:19 -07:00
kernel Merge branch 'page-refs' (page ref overflow) 2019-04-14 15:09:40 -07:00
lib Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-04-09 16:20:59 -10:00
LICENSES LICENSES: Add GCC runtime library exception text 2019-01-16 14:54:15 -07:00
mm Merge branch 'page-refs' (page ref overflow) 2019-04-14 15:09:40 -07:00
net Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping" 2019-04-11 15:41:14 -04:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-03-11 08:54:01 -07:00
scripts fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock 2019-04-06 07:01:55 -10:00
security apparmor: Restore Y/N in /sys for apparmor's "enabled" 2019-04-10 04:24:48 -07:00
sound Linux 5.1-rc5 2019-04-15 15:51:49 +10:00
tools for-linus-20190412 2019-04-13 16:23:16 -07:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt KVM/ARM fixes for 5.1 2019-03-28 19:07:30 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-04-12 12:49:54 +02:00
.cocciconfig
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.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap Update Nicolas Pitre's email address 2019-04-02 18:12:44 -10:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Char/Misc driver patches for 5.1-rc1 2019-03-06 14:18:59 -08:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS drm-misc-next for v5.2: 2019-04-24 10:12:50 +10:00
Makefile Linux 5.1-rc5 2019-04-14 15:17:41 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.