✓ CI.checkpatch: success for drm/xe/migrate: Fix CCS copy for small VRAM copy chunks (rev4)

[Patchwork]

== Series Details ==

Series: drm/xe/migrate: Fix CCS copy for small VRAM copy chunks (rev4)
URL   : https://patchwork.freedesktop.org/series/127874/
State : success

== Summary ==

+ KERNEL=/kernel
+ git clone https://gitlab.freedesktop.org/drm/maintainer-tools mt
Cloning into 'mt'...
warning: redirecting to https://gitlab.freedesktop.org/drm/maintainer-tools.git/
+ git -C mt rev-list -n1 origin/master
6030b24c1386b00de8187b5fb987e283a57b372a
+ cd /kernel
+ git config --global --add safe.directory /kernel
+ git log -n1
commit 627786f4e5d33f4d6b962a21287c676b6e0de424
Author: Thomas Hellström <thomas.hellstrom at linux.intel.com>
Date:   Mon Dec 18 13:56:54 2023 +0100

    drm/xe/migrate: Fix CCS copy for small VRAM copy chunks
    
    Since the migrate code is using the identity map for addressing VRAM,
    copy chunks may become as small as 64K if the VRAM resource is fragmented.
    
    However, a chunk size smaller that 1MiB may lead to the *next* chunk's
    offset into the CCS metadata backup memory may not be page-aligned, and
    the XY_CTRL_SURF_COPY_BLT command can't handle that, and even if it could,
    the current code doesn't handle the offset calculaton correctly.
    
    To fix this, make sure we align the size of VRAM copy chunks to 1MiB. If
    the remaining data to copy is smaller than that, that's not a problem,
    so use the remaining size. If the VRAM copy cunk becomes fragmented due
    to the size alignment restriction, don't use the identity map, but instead
    emit PTEs into the page-table like we do for system memory.
    
    v2:
    - Rebase
    v3:
    - Future proof somewhat by taking into account the real data size to
      flat CCS metadata size ratio. (Matt Roper)
    - Invert a couple of if-statements for better readability.
    - Fix support for 4K-granularity VRAM sizes. (Tested on DG1).
    
    Cc: Matt Roper <matthew.d.roper at intel.com>
    Cc: Matthew Auld <matthew.william.auld at gmail.com>
    Cc: Matthew Brost <matthew.brost at intel.com>
    Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
+ /mt/dim checkpatch 84e5d706cb0c11f2948a9f16d9e31ad5256b641c drm-intel
627786f4e drm/xe/migrate: Fix CCS copy for small VRAM copy chunks