Commit 4399e951 authored by Lucas De Marchi's avatar Lucas De Marchi Committed by Rodrigo Vivi
Browse files

drm/xe/mocs: Bring comment about mocs back to reality 



The mocs documentation was copied from i915 and doesn't match the
reality in xe. Reword it so it matches what the code is doing.

Reviewed-by: default avatarMatt Roper <matthew.d.roper@intel.com>
Link: https://lore.kernel.org/r/20231117174049.527192-2-lucas.demarchi@intel.com


Signed-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
parent 8735f861

drivers/gpu/drm/xe/xe_mocs.c

+11 −21
Original line number Diff line number Diff line
@@ -123,30 +123,20 @@ struct xe_mocs_info { 
 *

 * These tables are intended to be kept reasonably consistent across

 * HW platforms, and for ICL+, be identical across OSes. To achieve

 * that, for Icelake and above, list of entries is published as part

 * of bspec.

 * that, the list of entries is published as part of bspec.

 *

 * Entries not part of the following tables are undefined as far as

 * userspace is concerned and shouldn't be relied upon.  For Gen < 12

 * they will be initialized to PTE. Gen >= 12 don't have a setting for

 * PTE and those platforms except TGL/RKL will be initialized L3 WB to

 * catch accidental use of reserved and unused mocs indexes.

 * Entries not part of the following tables are undefined as far as userspace is

 * concerned and shouldn't be relied upon. The last few entries are reserved by

 * the hardware. They should be initialized according to bspec and never used.

 *

 * The last few entries are reserved by the hardware. For ICL+ they

 * should be initialized according to bspec and never used, for older

 * platforms they should never be written to.

 * NOTE1: These tables are part of bspec and defined as part of the hardware

 * interface. It is expected that, for specific hardware platform, existing

 * entries will remain constant and the table will only be updated by adding new

 * entries, filling unused positions.

 *

 * NOTE1: These tables are part of bspec and defined as part of hardware

 *       interface for ICL+. For older platforms, they are part of kernel

 *       ABI. It is expected that, for specific hardware platform, existing

 *       entries will remain constant and the table will only be updated by

 *       adding new entries, filling unused positions.

 *

 * NOTE2: For GEN >= 12 except TGL and RKL, reserved and unspecified MOCS

 *       indices have been set to L3 WB. These reserved entries should never

 *       be used, they may be changed to low performant variants with better

 *       coherency in the future if more entries are needed.

 *       For TGL/RKL, all the unspecified MOCS indexes are mapped to L3 UC.

 * NOTE2: Reserved and unspecified MOCS indices have been set to L3 WB. These

 * reserved entries should never be used. They may be changed to low performant

 * variants with better coherency in the future if more entries are needed.

 */



static const struct xe_mocs_entry gen12_mocs_desc[] = {