From f5d2904cf814f20b79e3e4c1b24a4ccc2411b7e0 Mon Sep 17 00:00:00 2001 From: Andi Shyti Date: Thu, 28 Mar 2024 08:34:03 +0100 Subject: [PATCH] drm/i915/gt: Disable HW load balancing for CCS The hardware should not dynamically balance the load between CCS engines. Wa_14019159160 recommends disabling it across all platforms. Fixes: d2eae8e98d59 ("drm/i915/dg2: Drop force_probe requirement") Signed-off-by: Andi Shyti Cc: Chris Wilson Cc: Joonas Lahtinen Cc: Matt Roper Cc: # v6.2+ Reviewed-by: Matt Roper Acked-by: Michal Mrozek Link: https://patchwork.freedesktop.org/patch/msgid/20240328073409.674098-2-andi.shyti@linux.intel.com --- drivers/gpu/drm/i915/gt/intel_gt_regs.h | 1 + drivers/gpu/drm/i915/gt/intel_workarounds.c | 23 +++++++++++++++++++-- 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h index 1f778b77f4f8..892860a757eb 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h @@ -1478,6 +1478,7 @@ #define ECOBITS_PPGTT_CACHE4B (0 << 8) #define GEN12_RCU_MODE _MMIO(0x14800) +#define XEHP_RCU_MODE_FIXED_SLICE_CCS_MODE REG_BIT(1) #define GEN12_RCU_MODE_CCS_ENABLE REG_BIT(0) #define CHV_FUSE_GT _MMIO(VLV_GUNIT_BASE + 0x2168) diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c index 6352e38e0fa0..a237e823364b 100644 --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c @@ -51,7 +51,8 @@ * registers belonging to BCS, VCS or VECS should be implemented in * xcs_engine_wa_init(). Workarounds for registers not belonging to a specific * engine's MMIO range but that are part of of the common RCS/CCS reset domain - * should be implemented in general_render_compute_wa_init(). + * should be implemented in general_render_compute_wa_init(). The settings + * about the CCS load balancing should be added in ccs_engine_wa_mode(). * * - GT workarounds: the list of these WAs is applied whenever these registers * revert to their default values: on GPU reset, suspend/resume [1]_, etc. @@ -2853,6 +2854,22 @@ add_render_compute_tuning_settings(struct intel_gt *gt, wa_write_clr(wal, GEN8_GARBCNTL, GEN12_BUS_HASH_CTL_BIT_EXC); } +static void ccs_engine_wa_mode(struct intel_engine_cs *engine, struct i915_wa_list *wal) +{ + struct intel_gt *gt = engine->gt; + + if (!IS_DG2(gt->i915)) + return; + + /* + * Wa_14019159160: This workaround, along with others, leads to + * significant challenges in utilizing load balancing among the + * CCS slices. Consequently, an architectural decision has been + * made to completely disable automatic CCS load balancing. + */ + wa_masked_en(wal, GEN12_RCU_MODE, XEHP_RCU_MODE_FIXED_SLICE_CCS_MODE); +} + /* * The workarounds in this function apply to shared registers in * the general render reset domain that aren't tied to a @@ -3003,8 +3020,10 @@ engine_init_workarounds(struct intel_engine_cs *engine, struct i915_wa_list *wal * to a single RCS/CCS engine's workaround list since * they're reset as part of the general render domain reset. */ - if (engine->flags & I915_ENGINE_FIRST_RENDER_COMPUTE) + if (engine->flags & I915_ENGINE_FIRST_RENDER_COMPUTE) { general_render_compute_wa_init(engine, wal); + ccs_engine_wa_mode(engine, wal); + } if (engine->class == COMPUTE_CLASS) ccs_engine_wa_init(engine, wal); -- 2.25.1