On Mon, 2022-06-13 at 09:53 -0700, Matt Roper wrote:
> As with past platforms, the bspec's performance tuning guide provides
> recommended MMIO settings. Although not technically "workarounds" we
> apply these through the workaround framework to ensure that they're
> re-applied at the proper times (e.g., on engine resets) and that any
> conflicts with real workarounds are flagged.
Reviewed-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
>
> Bspec: 72161
> Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/intel_gt_regs.h | 5 +++++
> drivers/gpu/drm/i915/gt/intel_workarounds.c | 9 +++++++++
> 2 files changed, 14 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index 226557018037..07ef111947b8 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -981,6 +981,11 @@
> #define XEHP_L3SCQREG7 _MMIO(0xb188)
> #define BLEND_FILL_CACHING_OPT_DIS REG_BIT(3)
>
> +#define XEHPC_L3SCRUB _MMIO(0xb18c)
> +#define SCRUB_CL_DWNGRADE_SHARED REG_BIT(12)
> +#define SCRUB_RATE_PER_BANK_MASK REG_GENMASK(2, 0)
> +#define SCRUB_RATE_4B_PER_CLK REG_FIELD_PREP(SCRUB_RATE_PER_BANK_MASK, 0x6)
> +
> #define L3SQCREG1_CCS0 _MMIO(0xb200)
> #define FLUSHALLNONCOH REG_BIT(5)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> index 1e982ac931dc..c4af51144216 100644
> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> @@ -2679,6 +2679,15 @@ general_render_compute_wa_init(struct intel_engine_cs *engine, struct i915_wa_li
> {
> struct drm_i915_private *i915 = engine->i915;
>
> + if (IS_PONTEVECCHIO(i915)) {
> + /*
> + * The following is not actually a "workaround" but rather
> + * a recommended tuning setting documented in the bspec's
> + * performance guide section.
> + */
> + wa_write(wal, XEHPC_L3SCRUB, SCRUB_CL_DWNGRADE_SHARED | SCRUB_RATE_4B_PER_CLK);
> + }
> +
> if (IS_XEHPSDV(i915)) {
> /* Wa_1409954639 */
> wa_masked_en(wal,
