From: Tvrtko Ursulin Date: Thu, 10 Jul 2025 20:33:52 +0000 (-0700) Subject: drm/xe: Waste fewer instructions in emit_wa_job() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aded26ccaaa87ec9d7665eb7be25be4c70672b28;p=thirdparty%2Fkernel%2Flinux.git drm/xe: Waste fewer instructions in emit_wa_job() I was debugging some unrelated issue and noticed the current code was very verbose. We can improve it easily by using the more common batch buffer building pattern. Before: bb->cs[bb->len++] = MI_LOAD_REGISTER_REG | MI_LRR_DST_CS_MMIO; c4d: 41 8b 56 10 mov 0x10(%r14),%edx c51: 49 8b 4e 08 mov 0x8(%r14),%rcx c55: 8d 72 01 lea 0x1(%rdx),%esi c58: 41 89 76 10 mov %esi,0x10(%r14) c5c: c7 04 91 01 00 08 15 movl $0x15080001,(%rcx,%rdx,4) bb->cs[bb->len++] = entry->reg.addr; c63: 8b 08 mov (%rax),%ecx c65: 41 8b 56 10 mov 0x10(%r14),%edx c69: 49 8b 76 08 mov 0x8(%r14),%rsi c6d: 81 e1 ff ff 3f 00 and $0x3fffff,%ecx c73: 8d 7a 01 lea 0x1(%rdx),%edi c76: 41 89 7e 10 mov %edi,0x10(%r14) c7a: 89 0c 96 mov %ecx,(%rsi,%rdx,4) ..etc.. After: *cs++ = MI_LOAD_REGISTER_REG | MI_LRR_DST_CS_MMIO; c52: 41 c7 04 24 01 00 08 movl $0x15080001,(%r12) c59: 15 *cs++ = entry->reg.addr; c5a: 8b 10 mov (%rax),%edx ..etc.. Resulting in the following binary change: add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-348 (-348) Function old new delta xe_gt_record_default_lrcs.cold 304 296 -8 xe_gt_record_default_lrcs 2200 1860 -340 Total: Before=13554, After=13206, chg -2.57% Signed-off-by: Tvrtko Ursulin Reviewed-by: Lucas De Marchi Reviewed-by: Matthew Brost Link: https://lore.kernel.org/r/20250710-lrc-refactors-v2-7-a5e2ca03f6bd@intel.com Signed-off-by: Lucas De Marchi --- diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c index 1cd1b551eb1f2..e6c11e6429019 100644 --- a/drivers/gpu/drm/xe/xe_gt.c +++ b/drivers/gpu/drm/xe/xe_gt.c @@ -194,6 +194,7 @@ static int emit_wa_job(struct xe_gt *gt, struct xe_exec_queue *q) unsigned long idx; struct xe_bb *bb; size_t bb_len = 0; + u32 *cs; /* count RMW registers as those will be handled separately */ xa_for_each(&sr->xa, idx, entry) { @@ -222,13 +223,15 @@ static int emit_wa_job(struct xe_gt *gt, struct xe_exec_queue *q) if (IS_ERR(bb)) return PTR_ERR(bb); + cs = bb->cs; + if (count) { /* * Emit single LRI with all non RMW regs: 1 leading dw + 2dw per * reg + 1 */ - bb->cs[bb->len++] = MI_LOAD_REGISTER_IMM | MI_LRI_NUM_REGS(count); + *cs++ = MI_LOAD_REGISTER_IMM | MI_LRI_NUM_REGS(count); xa_for_each(&sr->xa, idx, entry) { struct xe_reg reg = entry->reg; @@ -243,8 +246,8 @@ static int emit_wa_job(struct xe_gt *gt, struct xe_exec_queue *q) val |= entry->set_bits; - bb->cs[bb->len++] = reg.addr; - bb->cs[bb->len++] = val; + *cs++ = reg.addr; + *cs++ = val; xe_gt_dbg(gt, "REG[0x%x] = 0x%08x", reg.addr, val); } } @@ -256,46 +259,49 @@ static int emit_wa_job(struct xe_gt *gt, struct xe_exec_queue *q) if (entry->reg.masked || entry->clr_bits == ~0) continue; - bb->cs[bb->len++] = MI_LOAD_REGISTER_REG | MI_LRR_DST_CS_MMIO; - bb->cs[bb->len++] = entry->reg.addr; - bb->cs[bb->len++] = CS_GPR_REG(0, 0).addr; - - bb->cs[bb->len++] = MI_LOAD_REGISTER_IMM | MI_LRI_NUM_REGS(2) | - MI_LRI_LRM_CS_MMIO; - bb->cs[bb->len++] = CS_GPR_REG(0, 1).addr; - bb->cs[bb->len++] = entry->clr_bits; - bb->cs[bb->len++] = CS_GPR_REG(0, 2).addr; - bb->cs[bb->len++] = entry->set_bits; - - bb->cs[bb->len++] = MI_MATH(8); - bb->cs[bb->len++] = CS_ALU_INSTR_LOAD(SRCA, REG0); - bb->cs[bb->len++] = CS_ALU_INSTR_LOADINV(SRCB, REG1); - bb->cs[bb->len++] = CS_ALU_INSTR_AND; - bb->cs[bb->len++] = CS_ALU_INSTR_STORE(REG0, ACCU); - bb->cs[bb->len++] = CS_ALU_INSTR_LOAD(SRCA, REG0); - bb->cs[bb->len++] = CS_ALU_INSTR_LOAD(SRCB, REG2); - bb->cs[bb->len++] = CS_ALU_INSTR_OR; - bb->cs[bb->len++] = CS_ALU_INSTR_STORE(REG0, ACCU); - - bb->cs[bb->len++] = MI_LOAD_REGISTER_REG | MI_LRR_SRC_CS_MMIO; - bb->cs[bb->len++] = CS_GPR_REG(0, 0).addr; - bb->cs[bb->len++] = entry->reg.addr; + *cs++ = MI_LOAD_REGISTER_REG | MI_LRR_DST_CS_MMIO; + *cs++ = entry->reg.addr; + *cs++ = CS_GPR_REG(0, 0).addr; + + *cs++ = MI_LOAD_REGISTER_IMM | MI_LRI_NUM_REGS(2) | + MI_LRI_LRM_CS_MMIO; + *cs++ = CS_GPR_REG(0, 1).addr; + *cs++ = entry->clr_bits; + *cs++ = CS_GPR_REG(0, 2).addr; + *cs++ = entry->set_bits; + + *cs++ = MI_MATH(8); + *cs++ = CS_ALU_INSTR_LOAD(SRCA, REG0); + *cs++ = CS_ALU_INSTR_LOADINV(SRCB, REG1); + *cs++ = CS_ALU_INSTR_AND; + *cs++ = CS_ALU_INSTR_STORE(REG0, ACCU); + *cs++ = CS_ALU_INSTR_LOAD(SRCA, REG0); + *cs++ = CS_ALU_INSTR_LOAD(SRCB, REG2); + *cs++ = CS_ALU_INSTR_OR; + *cs++ = CS_ALU_INSTR_STORE(REG0, ACCU); + + *cs++ = MI_LOAD_REGISTER_REG | MI_LRR_SRC_CS_MMIO; + *cs++ = CS_GPR_REG(0, 0).addr; + *cs++ = entry->reg.addr; xe_gt_dbg(gt, "REG[%#x] = ~%#x|%#x\n", entry->reg.addr, entry->clr_bits, entry->set_bits); } /* reset used GPR */ - bb->cs[bb->len++] = MI_LOAD_REGISTER_IMM | MI_LRI_NUM_REGS(3) | MI_LRI_LRM_CS_MMIO; - bb->cs[bb->len++] = CS_GPR_REG(0, 0).addr; - bb->cs[bb->len++] = 0; - bb->cs[bb->len++] = CS_GPR_REG(0, 1).addr; - bb->cs[bb->len++] = 0; - bb->cs[bb->len++] = CS_GPR_REG(0, 2).addr; - bb->cs[bb->len++] = 0; + *cs++ = MI_LOAD_REGISTER_IMM | MI_LRI_NUM_REGS(3) | + MI_LRI_LRM_CS_MMIO; + *cs++ = CS_GPR_REG(0, 0).addr; + *cs++ = 0; + *cs++ = CS_GPR_REG(0, 1).addr; + *cs++ = 0; + *cs++ = CS_GPR_REG(0, 2).addr; + *cs++ = 0; } - xe_lrc_emit_hwe_state_instructions(q, bb); + cs = xe_lrc_emit_hwe_state_instructions(q, cs); + + bb->len = cs - bb->cs; ret = emit_job_sync(q, bb, HZ); diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c index 8bb2ca3af7d12..3a169011a2ad2 100644 --- a/drivers/gpu/drm/xe/xe_lrc.c +++ b/drivers/gpu/drm/xe/xe_lrc.c @@ -1888,7 +1888,7 @@ static const struct instr_state xe_hpg_svg_state[] = { { .instr = CMD_3DSTATE_DRAWING_RECTANGLE, .num_dw = 4 }, }; -void xe_lrc_emit_hwe_state_instructions(struct xe_exec_queue *q, struct xe_bb *bb) +u32 *xe_lrc_emit_hwe_state_instructions(struct xe_exec_queue *q, u32 *cs) { struct xe_gt *gt = q->hwe->gt; struct xe_device *xe = gt_to_xe(gt); @@ -1923,7 +1923,7 @@ void xe_lrc_emit_hwe_state_instructions(struct xe_exec_queue *q, struct xe_bb *b if (!state_table) { xe_gt_dbg(gt, "No non-register state to emit on graphics ver %d.%02d\n", GRAPHICS_VER(xe), GRAPHICS_VERx100(xe) % 100); - return; + return cs; } for (int i = 0; i < state_table_size; i++) { @@ -1946,12 +1946,14 @@ void xe_lrc_emit_hwe_state_instructions(struct xe_exec_queue *q, struct xe_bb *b instr == CMD_3DSTATE_DRAWING_RECTANGLE) instr = CMD_3DSTATE_DRAWING_RECTANGLE_FAST; - bb->cs[bb->len] = instr; + *cs = instr; if (!is_single_dw) - bb->cs[bb->len] |= (num_dw - 2); + *cs |= (num_dw - 2); - bb->len += num_dw; + cs += num_dw; } + + return cs; } struct xe_lrc_snapshot *xe_lrc_snapshot_capture(struct xe_lrc *lrc) diff --git a/drivers/gpu/drm/xe/xe_lrc.h b/drivers/gpu/drm/xe/xe_lrc.h index eb6e8de8c939e..b6c8053c581ba 100644 --- a/drivers/gpu/drm/xe/xe_lrc.h +++ b/drivers/gpu/drm/xe/xe_lrc.h @@ -112,7 +112,7 @@ void xe_lrc_dump_default(struct drm_printer *p, struct xe_gt *gt, enum xe_engine_class); -void xe_lrc_emit_hwe_state_instructions(struct xe_exec_queue *q, struct xe_bb *bb); +u32 *xe_lrc_emit_hwe_state_instructions(struct xe_exec_queue *q, u32 *cs); struct xe_lrc_snapshot *xe_lrc_snapshot_capture(struct xe_lrc *lrc); void xe_lrc_snapshot_capture_delayed(struct xe_lrc_snapshot *snapshot);