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

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.comSigned-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
parent 8735f861
...@@ -123,30 +123,20 @@ struct xe_mocs_info { ...@@ -123,30 +123,20 @@ struct xe_mocs_info {
* *
* These tables are intended to be kept reasonably consistent across * These tables are intended to be kept reasonably consistent across
* HW platforms, and for ICL+, be identical across OSes. To achieve * HW platforms, and for ICL+, be identical across OSes. To achieve
* that, for Icelake and above, list of entries is published as part * that, the list of entries is published as part of bspec.
* of bspec.
* *
* Entries not part of the following tables are undefined as far as * Entries not part of the following tables are undefined as far as userspace is
* userspace is concerned and shouldn't be relied upon. For Gen < 12 * concerned and shouldn't be relied upon. The last few entries are reserved by
* they will be initialized to PTE. Gen >= 12 don't have a setting for * the hardware. They should be initialized according to bspec and never used.
* PTE and those platforms except TGL/RKL will be initialized L3 WB to
* catch accidental use of reserved and unused mocs indexes.
* *
* The last few entries are reserved by the hardware. For ICL+ they * NOTE1: These tables are part of bspec and defined as part of the hardware
* should be initialized according to bspec and never used, for older * interface. It is expected that, for specific hardware platform, existing
* platforms they should never be written to. * 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 * NOTE2: Reserved and unspecified MOCS indices have been set to L3 WB. These
* interface for ICL+. For older platforms, they are part of kernel * reserved entries should never be used. They may be changed to low performant
* ABI. It is expected that, for specific hardware platform, existing * variants with better coherency in the future if more entries are needed.
* 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.
*/ */
static const struct xe_mocs_entry gen12_mocs_desc[] = { static const struct xe_mocs_entry gen12_mocs_desc[] = {
......
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