github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-28 00:53:34 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

drm/i915/gt: Document the eviction of the Flat-CCS objects

Browse Source 
Capture the eviction details for Flat-CCS capable, lmem objects.

v2:
  Fix the Flat-ccs capbility of lmem obj with smem residency
  possibility [Thomas]
v3:
  Fixed the suggestions [Matt]

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
cc: Thomas Hellstrom <thomas.hellstrom@linux.intel.com>
cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220502142618.2704-4-ramalingam.c@intel.com
This commit is contained in:
Ramalingam C 2022-05-02 19:56:18 +05:30
parent b8c9d486af
commit 6e29832f61
1 changed files with 14 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/gpu/drm/i915/gt/intel_migrate.c
View File

@ -485,16 +485,21 @@ static bool wa_1209644611_applies(int ver, u32 size)
* And CCS data can be copied in and out of CCS region through
* XY_CTRL_SURF_COPY_BLT. CPU can't access the CCS data directly.
*
* When we exhaust the lmem, if the object's placements support smem, then we can
* directly decompress the compressed lmem object into smem and start using it
* from smem itself.
* I915 supports Flat-CCS on lmem only objects. When an objects has smem in
* its preference list, on memory pressure, i915 needs to migrate the lmem
* content into smem. If the lmem object is Flat-CCS compressed by userspace,
* then i915 needs to decompress it. But I915 lack the required information
* for such decompression. Hence I915 supports Flat-CCS only on lmem only objects.
*
* But when we need to swapout the compressed lmem object into a smem region
* though objects' placement doesn't support smem, then we copy the lmem content
* as it is into smem region along with ccs data (using XY_CTRL_SURF_COPY_BLT).
* When the object is referred, lmem content will be swaped in along with
* restoration of the CCS data (using XY_CTRL_SURF_COPY_BLT) at corresponding
* location.
* When we exhaust the lmem, Flat-CCS capable objects' lmem backing memory can
* be temporarily evicted to smem, along with the auxiliary CCS state, where
* it can be potentially swapped-out at a later point, if required.
* If userspace later touches the evicted pages, then we always move
* the backing memory back to lmem, which includes restoring the saved CCS state,
* and potentially performing any required swap-in.
*
* For the migration of the lmem objects with smem in placement list, such as
* {lmem, smem}, objects are treated as non Flat-CCS capable objects.
*/
static inline u32 *i915_flush_dw(u32 *cmd, u32 flags)