6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andi Shyti andi.shyti@linux.intel.com
commit bc9a1ec01289e6e7259dc5030b413a9c6654a99a upstream.
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 andi.shyti@linux.intel.com Cc: Chris Wilson chris.p.wilson@linux.intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: Matt Roper matthew.d.roper@intel.com Cc: stable@vger.kernel.org # v6.2+ Reviewed-by: Matt Roper matthew.d.roper@intel.com Acked-by: Michal Mrozek michal.mrozek@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20240328073409.674098-2-andi.s... (cherry picked from commit f5d2904cf814f20b79e3e4c1b24a4ccc2411b7e0) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(-)
--- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h @@ -1468,6 +1468,7 @@ #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) --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c @@ -50,7 +50,8 @@ * 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. @@ -2823,6 +2824,22 @@ add_render_compute_tuning_settings(struc 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 @@ -2970,8 +2987,10 @@ engine_init_workarounds(struct intel_eng * 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);