gfx_v10_1_10_cleaner_shader.asm

  1/* SPDX-License-Identifier: MIT */
  2/*
  3 * Copyright 2025 Advanced Micro Devices, Inc.
  4 *
  5 * Permission is hereby granted, free of charge, to any person obtaining a
  6 * copy of this software and associated documentation files (the "Software"),
  7 * to deal in the Software without restriction, including without limitation
  8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  9 * and/or sell copies of the Software, and to permit persons to whom the
 10 * Software is furnished to do so, subject to the following conditions:
 11 *
 12 * The above copyright notice and this permission notice shall be included in
 13 * all copies or substantial portions of the Software.
 14 *
 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 18 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 21 * OTHER DEALINGS IN THE SOFTWARE.
 22 */
 23
 24// This shader is to clean LDS, SGPRs and VGPRs. It is  first 64 Dwords or 256 bytes of 256 Dwords cleaner shader.
 25
 26// GFX10.1 : Clear SGPRs, VGPRs and LDS
 27//   Launch 32 waves per CU (16 per SIMD) as a workgroup (threadgroup) to fill every wave slot
 28//   Waves are "wave32" and have 64 VGPRs each, which uses all 1024 VGPRs per SIMD
 29//   Waves are launched in "CU" mode, and the workgroup shares 64KB of LDS (half of the WGP's LDS)
 30//      It takes 2 workgroups to use all of LDS: one on each CU of the WGP
 31//   Each wave clears SGPRs 0 - 107
 32//   Each wave clears VGPRs 0 - 63
 33//   The first wave of the workgroup clears its 64KB of LDS
 34//   The shader starts with "S_BARRIER" to ensure SPI has launched all waves of the workgroup
 35//       before any wave in the workgroup could end.  Without this, it is possible not all SGPRs get cleared.
 36
 37
 38shader main
 39  asic(GFX10.1)
 40  type(CS)
 41  wave_size(32)
 42// Note: original source code from SQ team
 43//
 44// Create 32 waves in a threadgroup (CS waves)
 45// Each allocates 64 VGPRs
 46// The workgroup allocates all of LDS (64kbytes)
 47//
 48// Takes about 2500 clocks to run.
 49//   (theorhetical fastest = 1024clks vgpr + 640lds = 1660 clks)
 50//
 51  S_BARRIER
 52  s_cmp_eq_u32 s0, 1                                // Bit0 is set, sgpr0 is set then clear VGPRS and LDS as FW set COMPUTE_USER_DATA_0
 53  s_cbranch_scc0  label_0023                        // Clean VGPRs and LDS if sgpr0 of wave is set, scc = (s0 == 1)
 54
 55  s_mov_b32     s2, 0x00000038  // Loop 64/8=8 times  (loop unrolled for performance)
 56  s_mov_b32     m0, 0
 57  //
 58  // CLEAR VGPRs
 59  //
 60label_0005:
 61  v_movreld_b32     v0, 0
 62  v_movreld_b32     v1, 0
 63  v_movreld_b32     v2, 0
 64  v_movreld_b32     v3, 0
 65  v_movreld_b32     v4, 0
 66  v_movreld_b32     v5, 0
 67  v_movreld_b32     v6, 0
 68  v_movreld_b32     v7, 0
 69  s_mov_b32         m0, s2
 70  s_sub_u32     s2, s2, 8
 71  s_cbranch_scc0  label_0005
 72  //
 73  s_mov_b32     s2, 0x80000000                       // Bit31 is first_wave
 74  s_and_b32     s2, s2, s1                           // sgpr0 has tg_size (first_wave) term as in ucode only COMPUTE_PGM_RSRC2.tg_size_en is set
 75  s_cbranch_scc0  label_0023                         // Clean LDS if its first wave of ThreadGroup/WorkGroup
 76  // CLEAR LDS
 77  //
 78  s_mov_b32 exec_lo, 0xffffffff
 79  s_mov_b32 exec_hi, 0xffffffff
 80  v_mbcnt_lo_u32_b32  v1, exec_hi, 0          // Set V1 to thread-ID (0..63)
 81  v_mbcnt_hi_u32_b32  v1, exec_lo, v1        // Set V1 to thread-ID (0..63)
 82  v_mul_u32_u24  v1, 0x00000008, v1          // * 8, so each thread is a double-dword address (8byte)
 83  s_mov_b32     s2, 0x00000003f                    // 64 loop iterations
 84  s_mov_b32     m0, 0xffffffff
 85  // Clear all of LDS space
 86  // Each FirstWave of WorkGroup clears 64kbyte block
 87
 88label_001F:
 89  ds_write2_b64  v1, v[2:3], v[2:3] offset1:32
 90  ds_write2_b64  v1, v[4:5], v[4:5] offset0:64 offset1:96
 91  v_add_co_u32     v1, vcc, 0x00000400, v1
 92  s_sub_u32     s2, s2, 1
 93  s_cbranch_scc0  label_001F
 94
 95  //
 96  // CLEAR SGPRs
 97  //
 98label_0023:
 99  s_mov_b32     m0, 0x00000068  // Loop 108/4=27 times  (loop unrolled for performance)
100label_sgpr_loop:
101  s_movreld_b32     s0, s0
102  s_movreld_b32     s1, s0
103  s_movreld_b32     s2, s0
104  s_movreld_b32     s3, s0
105  s_sub_u32         m0, m0, 4
106  s_cbranch_scc0  label_sgpr_loop
107
108  //clear vcc
109  s_mov_b64 vcc, 0          //clear vcc
110  //s_setreg_imm32_b32 hw_reg_shader_flat_scratch_lo, 0   //clear  flat scratch lo SGPR
111  //s_setreg_imm32_b32 hw_reg_shader_flat_scratch_hi, 0    //clear  flat scratch hi SGPR
112  s_mov_b64 ttmp0, 0        //Clear ttmp0 and ttmp1
113  s_mov_b64 ttmp2, 0        //Clear ttmp2 and ttmp3
114  s_mov_b64 ttmp4, 0        //Clear ttmp4 and ttmp5
115  s_mov_b64 ttmp6, 0        //Clear ttmp6 and ttmp7
116  s_mov_b64 ttmp8, 0        //Clear ttmp8 and ttmp9
117  s_mov_b64 ttmp10, 0       //Clear ttmp10 and ttmp11
118  s_mov_b64 ttmp12, 0       //Clear ttmp12 and ttmp13
119  s_mov_b64 ttmp14, 0       //Clear ttmp14 and ttmp15
120
121 s_endpgm
122
123end
124
125