From 9a939ebb47a0d37a6b29e3dbb1b20bdc9538a721 Mon Sep 17 00:00:00 2001 From: Jordan Justen Date: Mon, 15 Feb 2016 15:17:15 -0800 Subject: [PATCH] i965/gen7: Use predicated rendering for indirect compute On gen7 (Ivy Bridge, Haswell), we will get a GPU hang if an indirect dispatch is used, but one of the dimensions is 0. Therefore we use predicated rendering on the GPGPU_WALKER command to handle this case. Fixes piglit test: spec/arb_compute_shader/zero-dispatch-size From the ARB_compute_shader spec, under DispatchCompute: "If the work group count in any dimension is zero, no work groups are dispatched." And then for DispatchComputeIndirect: ... "is equivalent (assuming no errors are generated) to calling DispatchCompute with , and " ... Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94100 Signed-off-by: Jordan Justen Reviewed-by: Ben Widawsky Reviewed-by: Kenneth Graunke Tested-by: Ilia Mirkin --- src/mesa/drivers/dri/i965/brw_compute.c | 96 +++++++++++++++++++++---- src/mesa/drivers/dri/i965/brw_defines.h | 1 + 2 files changed, 83 insertions(+), 14 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_compute.c b/src/mesa/drivers/dri/i965/brw_compute.c index d9f181a1cbf..0d2aca5b78a 100644 --- a/src/mesa/drivers/dri/i965/brw_compute.c +++ b/src/mesa/drivers/dri/i965/brw_compute.c @@ -34,6 +34,84 @@ #include "brw_defines.h" +static void +prepare_indirect_gpgpu_walker(struct brw_context *brw) +{ + GLintptr indirect_offset = brw->compute.num_work_groups_offset; + drm_intel_bo *bo = brw->compute.num_work_groups_bo; + + brw_load_register_mem(brw, GEN7_GPGPU_DISPATCHDIMX, bo, + I915_GEM_DOMAIN_VERTEX, 0, + indirect_offset + 0); + brw_load_register_mem(brw, GEN7_GPGPU_DISPATCHDIMY, bo, + I915_GEM_DOMAIN_VERTEX, 0, + indirect_offset + 4); + brw_load_register_mem(brw, GEN7_GPGPU_DISPATCHDIMZ, bo, + I915_GEM_DOMAIN_VERTEX, 0, + indirect_offset + 8); + + if (brw->gen > 7) + return; + + /* Clear upper 32-bits of SRC0 and all 64-bits of SRC1 */ + BEGIN_BATCH(7); + OUT_BATCH(MI_LOAD_REGISTER_IMM | (7 - 2)); + OUT_BATCH(MI_PREDICATE_SRC0 + 4); + OUT_BATCH(0u); + OUT_BATCH(MI_PREDICATE_SRC1 + 0); + OUT_BATCH(0u); + OUT_BATCH(MI_PREDICATE_SRC1 + 4); + OUT_BATCH(0u); + ADVANCE_BATCH(); + + /* Load compute_dispatch_indirect_x_size into SRC0 */ + brw_load_register_mem(brw, MI_PREDICATE_SRC0, bo, + I915_GEM_DOMAIN_INSTRUCTION, 0, + indirect_offset + 0); + + /* predicate = (compute_dispatch_indirect_x_size == 0); */ + BEGIN_BATCH(1); + OUT_BATCH(GEN7_MI_PREDICATE | + MI_PREDICATE_LOADOP_LOAD | + MI_PREDICATE_COMBINEOP_SET | + MI_PREDICATE_COMPAREOP_SRCS_EQUAL); + ADVANCE_BATCH(); + + /* Load compute_dispatch_indirect_y_size into SRC0 */ + brw_load_register_mem(brw, MI_PREDICATE_SRC0, bo, + I915_GEM_DOMAIN_INSTRUCTION, 0, + indirect_offset + 4); + + /* predicate |= (compute_dispatch_indirect_y_size == 0); */ + BEGIN_BATCH(1); + OUT_BATCH(GEN7_MI_PREDICATE | + MI_PREDICATE_LOADOP_LOAD | + MI_PREDICATE_COMBINEOP_OR | + MI_PREDICATE_COMPAREOP_SRCS_EQUAL); + ADVANCE_BATCH(); + + /* Load compute_dispatch_indirect_z_size into SRC0 */ + brw_load_register_mem(brw, MI_PREDICATE_SRC0, bo, + I915_GEM_DOMAIN_INSTRUCTION, 0, + indirect_offset + 8); + + /* predicate |= (compute_dispatch_indirect_z_size == 0); */ + BEGIN_BATCH(1); + OUT_BATCH(GEN7_MI_PREDICATE | + MI_PREDICATE_LOADOP_LOAD | + MI_PREDICATE_COMBINEOP_OR | + MI_PREDICATE_COMPAREOP_SRCS_EQUAL); + ADVANCE_BATCH(); + + /* predicate = !predicate; */ + BEGIN_BATCH(1); + OUT_BATCH(GEN7_MI_PREDICATE | + MI_PREDICATE_LOADOP_LOADINV | + MI_PREDICATE_COMBINEOP_OR | + MI_PREDICATE_COMPAREOP_FALSE); + ADVANCE_BATCH(); +} + static void brw_emit_gpgpu_walker(struct brw_context *brw) { @@ -45,20 +123,10 @@ brw_emit_gpgpu_walker(struct brw_context *brw) if (brw->compute.num_work_groups_bo == NULL) { indirect_flag = 0; } else { - GLintptr indirect_offset = brw->compute.num_work_groups_offset; - drm_intel_bo *bo = brw->compute.num_work_groups_bo; - - indirect_flag = GEN7_GPGPU_INDIRECT_PARAMETER_ENABLE; - - brw_load_register_mem(brw, GEN7_GPGPU_DISPATCHDIMX, bo, - I915_GEM_DOMAIN_VERTEX, 0, - indirect_offset + 0); - brw_load_register_mem(brw, GEN7_GPGPU_DISPATCHDIMY, bo, - I915_GEM_DOMAIN_VERTEX, 0, - indirect_offset + 4); - brw_load_register_mem(brw, GEN7_GPGPU_DISPATCHDIMZ, bo, - I915_GEM_DOMAIN_VERTEX, 0, - indirect_offset + 8); + indirect_flag = + GEN7_GPGPU_INDIRECT_PARAMETER_ENABLE | + (brw->gen == 7 ? GEN7_GPGPU_PREDICATE_ENABLE : 0); + prepare_indirect_gpgpu_walker(brw); } const unsigned simd_size = prog_data->simd_size; diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h index b1fa559129b..60b696cfb98 100644 --- a/src/mesa/drivers/dri/i965/brw_defines.h +++ b/src/mesa/drivers/dri/i965/brw_defines.h @@ -2938,6 +2938,7 @@ enum brw_wm_barycentric_interp_mode { #define GPGPU_WALKER 0x7105 /* GEN7 DW0 */ # define GEN7_GPGPU_INDIRECT_PARAMETER_ENABLE (1 << 10) +# define GEN7_GPGPU_PREDICATE_ENABLE (1 << 8) /* GEN8+ DW2 */ # define GPGPU_WALKER_INDIRECT_LENGTH_SHIFT 0 # define GPGPU_WALKER_INDIRECT_LENGTH_MASK INTEL_MASK(15, 0) -- 2.30.2