From a4b6e74c88cc9c15257d1aaee8024d8eaa9813e7 Mon Sep 17 00:00:00 2001 From: Umesh Nerlige Ramappa Date: Mon, 12 Dec 2022 14:08:59 -0800 Subject: [PATCH] drm/i915/mtl: Resize noa_wait BO size to save restore GPR regs On MTL, gt->scratch was using stolen lmem. An MI_SRM to stolen lmem caused a hang that was attributed to saving and restoring the GPR registers used for noa_wait. Add an additional page in noa_wait BO to save/restore GPR registers for the noa_wait logic. Signed-off-by: Umesh Nerlige Ramappa Reviewed-by: Ashutosh Dixit Signed-off-by: John Harrison Link: https://patchwork.freedesktop.org/patch/msgid/20221212220902.1819159-2-umesh.nerlige.ramappa@intel.com --- drivers/gpu/drm/i915/gt/intel_gt_types.h | 6 ------ drivers/gpu/drm/i915/i915_perf.c | 25 +++++++++++++++++-------- 2 files changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_gt_types.h b/drivers/gpu/drm/i915/gt/intel_gt_types.h index 0b6da2a..f08c255 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_types.h +++ b/drivers/gpu/drm/i915/gt/intel_gt_types.h @@ -304,12 +304,6 @@ enum intel_gt_scratch_field { /* 8 bytes */ INTEL_GT_SCRATCH_FIELD_COHERENTL3_WA = 256, - - /* 6 * 8 bytes */ - INTEL_GT_SCRATCH_FIELD_PERF_CS_GPR = 2048, - - /* 4 bytes */ - INTEL_GT_SCRATCH_FIELD_PERF_PREDICATE_RESULT_1 = 2096, }; #endif /* __INTEL_GT_TYPES_H__ */ diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index 963175f..cdd66f2 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -1845,8 +1845,7 @@ static u32 *save_restore_register(struct i915_perf_stream *stream, u32 *cs, for (d = 0; d < dword_count; d++) { *cs++ = cmd; *cs++ = i915_mmio_reg_offset(reg) + 4 * d; - *cs++ = intel_gt_scratch_offset(stream->engine->gt, - offset) + 4 * d; + *cs++ = i915_ggtt_offset(stream->noa_wait) + offset + 4 * d; *cs++ = 0; } @@ -1879,7 +1878,13 @@ static int alloc_noa_wait(struct i915_perf_stream *stream) MI_PREDICATE_RESULT_2_ENGINE(base) : MI_PREDICATE_RESULT_1(RENDER_RING_BASE); - bo = i915_gem_object_create_internal(i915, 4096); + /* + * gt->scratch was being used to save/restore the GPR registers, but on + * MTL the scratch uses stolen lmem. An MI_SRM to this memory region + * causes an engine hang. Instead allocate an additional page here to + * save/restore GPR registers + */ + bo = i915_gem_object_create_internal(i915, 8192); if (IS_ERR(bo)) { drm_err(&i915->drm, "Failed to allocate NOA wait batchbuffer\n"); @@ -1913,14 +1918,19 @@ retry: goto err_unpin; } + stream->noa_wait = vma; + +#define GPR_SAVE_OFFSET 4096 +#define PREDICATE_SAVE_OFFSET 4160 + /* Save registers. */ for (i = 0; i < N_CS_GPR; i++) cs = save_restore_register( stream, cs, true /* save */, CS_GPR(i), - INTEL_GT_SCRATCH_FIELD_PERF_CS_GPR + 8 * i, 2); + GPR_SAVE_OFFSET + 8 * i, 2); cs = save_restore_register( stream, cs, true /* save */, mi_predicate_result, - INTEL_GT_SCRATCH_FIELD_PERF_PREDICATE_RESULT_1, 1); + PREDICATE_SAVE_OFFSET, 1); /* First timestamp snapshot location. */ ts0 = cs; @@ -2036,10 +2046,10 @@ retry: for (i = 0; i < N_CS_GPR; i++) cs = save_restore_register( stream, cs, false /* restore */, CS_GPR(i), - INTEL_GT_SCRATCH_FIELD_PERF_CS_GPR + 8 * i, 2); + GPR_SAVE_OFFSET + 8 * i, 2); cs = save_restore_register( stream, cs, false /* restore */, mi_predicate_result, - INTEL_GT_SCRATCH_FIELD_PERF_PREDICATE_RESULT_1, 1); + PREDICATE_SAVE_OFFSET, 1); /* And return to the ring. */ *cs++ = MI_BATCH_BUFFER_END; @@ -2049,7 +2059,6 @@ retry: i915_gem_object_flush_map(bo); __i915_gem_object_release_map(bo); - stream->noa_wait = vma; goto out_ww; err_unpin: -- 2.7.4