[PATCH] drm/amdgpu/gfx9: Convert `//` to `/* ... */` in cleaner shader code

Christian König christian.koenig at amd.com
Wed Sep 4 10:50:50 UTC 2024


Am 04.09.24 um 11:33 schrieb Srinivasan Shanmugam:
> This commit updates the comment style in the cleaner shader code from
> `//` to `/* ... */` to adhere to the Linux kernel coding style.
>
> The comments describe the operation of the cleaner shader, which is used
> to clean LDS, SGPRs, and VGPRs. The shader uses two kernels launched
> separately to clean VGPRs, LDS, and lower SGPRs, and to clean remaining
> SGPRs.
>
> Cc: Christian König <christian.koenig at amd.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam at amd.com>

Acked-by: Christian König <christian.koenig at amd.com>

> ---
>   .../amd/amdgpu/gfx_v9_4_3_cleaner_shader.asm  | 139 +++++++++---------
>   1 file changed, 72 insertions(+), 67 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3_cleaner_shader.asm b/drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3_cleaner_shader.asm
> index d5325ef80ab0..4a61562b9bab 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3_cleaner_shader.asm
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3_cleaner_shader.asm
> @@ -21,47 +21,52 @@
>    * OTHER DEALINGS IN THE SOFTWARE.
>    */
>   
> -// This shader is to clean LDS, SGPRs and VGPRs. It is  first 64 Dwords or 256 bytes of 192 Dwords cleaner shader.
> -//To turn this shader program on for complitaion change this to main and lower shader main to main_1
> -
> -// MI300 : Clear SGPRs, VGPRs and LDS
> -//   Uses two kernels launched separately:
> -//   1. Clean VGPRs, LDS, and lower SGPRs
> -//        Launches one workgroup per CU, each workgroup with 4x wave64 per SIMD in the CU
> -//        Waves are "wave64" and have 128 VGPRs each, which uses all 512 VGPRs per SIMD
> -//        Waves in the workgroup share the 64KB of LDS
> -//        Each wave clears SGPRs 0 - 95. Because there are 4 waves/SIMD, this is physical SGPRs 0-383
> -//        Each wave clears 128 VGPRs, so all 512 in the SIMD
> -//        The first wave of the workgroup clears its 64KB of LDS
> -//        The shader starts with "S_BARRIER" to ensure SPI has launched all waves of the workgroup
> -//          before any wave in the workgroup could end.  Without this, it is possible not all SGPRs get cleared.
> -//    2. Clean remaining SGPRs
> -//        Launches a workgroup with 24 waves per workgroup, yielding 6 waves per SIMD in each CU
> -//        Waves are allocating 96 SGPRs
> -//          CP sets up SPI_RESOURCE_RESERVE_* registers to prevent these waves from allocating SGPRs 0-223.
> -//          As such, these 6 waves per SIMD are allocated physical SGPRs 224-799
> -//        Barriers do not work for >16 waves per workgroup, so we cannot start with S_BARRIER
> -//          Instead, the shader starts with an S_SETHALT 1. Once all waves are launched CP will send unhalt command
> -//        The shader then clears all SGPRs allocated to it, cleaning out physical SGPRs 224-799
> +/*
> + * This shader is to clean LDS, SGPRs and VGPRs. It is  first 64 Dwords or 256 bytes of 192 Dwords cleaner shader.
> + * To turn this shader program on for complitaion change this to main and lower shader main to main_1
> + *
> + * MI300 : Clear SGPRs, VGPRs and LDS
> + *   Uses two kernels launched separately:
> + *   1. Clean VGPRs, LDS, and lower SGPRs
> + *        Launches one workgroup per CU, each workgroup with 4x wave64 per SIMD in the CU
> + *        Waves are "wave64" and have 128 VGPRs each, which uses all 512 VGPRs per SIMD
> + *        Waves in the workgroup share the 64KB of LDS
> + *        Each wave clears SGPRs 0 - 95. Because there are 4 waves/SIMD, this is physical SGPRs 0-383
> + *        Each wave clears 128 VGPRs, so all 512 in the SIMD
> + *        The first wave of the workgroup clears its 64KB of LDS
> + *        The shader starts with "S_BARRIER" to ensure SPI has launched all waves of the workgroup
> + *          before any wave in the workgroup could end.  Without this, it is possible not all SGPRs get cleared.
> + *    2. Clean remaining SGPRs
> + *        Launches a workgroup with 24 waves per workgroup, yielding 6 waves per SIMD in each CU
> + *        Waves are allocating 96 SGPRs
> + *          CP sets up SPI_RESOURCE_RESERVE_* registers to prevent these waves from allocating SGPRs 0-223.
> + *          As such, these 6 waves per SIMD are allocated physical SGPRs 224-799
> + *       Barriers do not work for >16 waves per workgroup, so we cannot start with S_BARRIER
> + *       Instead, the shader starts with an S_SETHALT 1. Once all waves are launched CP will send unhalt command
> + *       The shader then clears all SGPRs allocated to it, cleaning out physical SGPRs 224-799
> + */
>    
>   shader main
>     asic(MI300)
>     type(CS)
>     wave_size(64)
> -// Note: original source code from SQ team
>   
> -//   (theorhetical fastest = ~512clks vgpr + 1536 lds + ~128 sgpr  = 2176 clks)
> +/*
> + * Note: original source code from SQ team
> + *
> + * (theorhetical fastest = ~512clks vgpr + 1536 lds + ~128 sgpr  = 2176 clks)
> + */
>   
> -  s_cmp_eq_u32 s0, 1                                // Bit0 is set, sgpr0 is set then clear VGPRS and LDS as FW set COMPUTE_USER_DATA_3
> -  s_cbranch_scc0  label_0023                        // Clean VGPRs and LDS if sgpr0 of wave is set, scc = (s3 == 1)
> +  s_cmp_eq_u32 s0, 1                                /* Bit0 is set, sgpr0 is set then clear VGPRS and LDS as FW set COMPUTE_USER_DATA_3 */
> +  s_cbranch_scc0  label_0023                        /* Clean VGPRs and LDS if sgpr0 of wave is set, scc = (s3 == 1) */
>     S_BARRIER
>   
>     s_movk_i32    m0, 0x0000
> -  s_mov_b32     s2, 0x00000078  // Loop 128/8=16 times  (loop unrolled for performance)
> -  //
> -  // CLEAR VGPRs
> -  //
> -  s_set_gpr_idx_on  s2, 0x8    // enable Dest VGPR indexing
> +  s_mov_b32     s2, 0x00000078  /* Loop 128/8=16 times  (loop unrolled for performance) */
> +/*
> + * CLEAR VGPRs
> + */
> +  s_set_gpr_idx_on  s2, 0x8    /* enable Dest VGPR indexing */
>   label_0005:
>     v_mov_b32     v0, 0
>     v_mov_b32     v1, 0
> @@ -75,24 +80,24 @@ label_0005:
>     s_set_gpr_idx_idx  s2
>     s_cbranch_scc0  label_0005
>     s_set_gpr_idx_off
> -
> -  //
> -  //
> -
> -  s_mov_b32     s2, 0x80000000                      // Bit31 is first_wave
> -  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
> -  s_cbranch_scc0  label_clean_sgpr_1                // Clean LDS if its first wave of ThreadGroup/WorkGroup
> -  // CLEAR LDS
> -  //
> +
> +  s_mov_b32     s2, 0x80000000                      /* Bit31 is first_wave */
> +  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 */
> +  s_cbranch_scc0  label_clean_sgpr_1                /* Clean LDS if its first wave of ThreadGroup/WorkGroup */
> +/*
> + * CLEAR LDS
> + */
>     s_mov_b32 exec_lo, 0xffffffff
>     s_mov_b32 exec_hi, 0xffffffff
> -  v_mbcnt_lo_u32_b32  v1, exec_hi, 0          // Set V1 to thread-ID (0..63)
> -  v_mbcnt_hi_u32_b32  v1, exec_lo, v1         // Set V1 to thread-ID (0..63)
> -  v_mul_u32_u24  v1, 0x00000008, v1           // * 8, so each thread is a double-dword address (8byte)
> -  s_mov_b32     s2, 0x00000003f               // 64 loop iteraions
> +  v_mbcnt_lo_u32_b32  v1, exec_hi, 0          /* Set V1 to thread-ID (0..63) */
> +  v_mbcnt_hi_u32_b32  v1, exec_lo, v1         /* Set V1 to thread-ID (0..63) */
> +  v_mul_u32_u24  v1, 0x00000008, v1           /* * 8, so each thread is a double-dword address (8byte) */
> +  s_mov_b32     s2, 0x00000003f               /* 64 loop iteraions */
>     s_mov_b32     m0, 0xffffffff
> -  // Clear all of LDS space
> -  // Each FirstWave of WorkGroup clears 64kbyte block
> +/*
> + * Clear all of LDS space
> + * Each FirstWave of WorkGroup clears 64kbyte block
> + */
>    
>   label_001F:
>     ds_write2_b64  v1, v[2:3], v[2:3] offset1:32
> @@ -100,11 +105,11 @@ label_001F:
>     v_add_co_u32     v1, vcc, 0x00000400, v1
>     s_sub_u32     s2, s2, 1
>     s_cbranch_scc0  label_001F
> -  //
> -  // CLEAR SGPRs
> -  //
> +/*
> + * CLEAR SGPRs
> + */
>   label_clean_sgpr_1:
> -  s_mov_b32     m0, 0x0000005c   // Loop 96/4=24 times  (loop unrolled for performance)
> +  s_mov_b32     m0, 0x0000005c   /* Loop 96/4=24 times  (loop unrolled for performance) */
>     s_nop 0
>   label_sgpr_loop:
>     s_movreld_b32     s0, 0
> @@ -114,25 +119,25 @@ label_sgpr_loop:
>     s_sub_u32         m0, m0, 4
>     s_cbranch_scc0  label_sgpr_loop
>    
> -  //clear vcc, flat scratch
> -  s_mov_b32 flat_scratch_lo, 0   //clear  flat scratch lo SGPR
> -  s_mov_b32 flat_scratch_hi, 0   //clear  flat scratch hi SGPR
> -  s_mov_b64 vcc, 0               //clear vcc
> -  s_mov_b64 ttmp0, 0             //Clear ttmp0 and ttmp1
> -  s_mov_b64 ttmp2, 0             //Clear ttmp2 and ttmp3
> -  s_mov_b64 ttmp4, 0             //Clear ttmp4 and ttmp5
> -  s_mov_b64 ttmp6, 0             //Clear ttmp6 and ttmp7
> -  s_mov_b64 ttmp8, 0             //Clear ttmp8 and ttmp9
> -  s_mov_b64 ttmp10, 0            //Clear ttmp10 and ttmp11
> -  s_mov_b64 ttmp12, 0            //Clear ttmp12 and ttmp13
> -  s_mov_b64 ttmp14, 0            //Clear ttmp14 and ttmp15
> +  /* clear vcc, flat scratch */
> +  s_mov_b32 flat_scratch_lo, 0   /* clear flat scratch lo SGPR */
> +  s_mov_b32 flat_scratch_hi, 0   /* clear flat scratch hi SGPR */
> +  s_mov_b64 vcc, 0               /* clear vcc */
> +  s_mov_b64 ttmp0, 0             /* Clear ttmp0 and ttmp1 */
> +  s_mov_b64 ttmp2, 0             /* Clear ttmp2 and ttmp3 */
> +  s_mov_b64 ttmp4, 0             /* Clear ttmp4 and ttmp5 */
> +  s_mov_b64 ttmp6, 0             /* Clear ttmp6 and ttmp7 */
> +  s_mov_b64 ttmp8, 0             /* Clear ttmp8 and ttmp9 */
> +  s_mov_b64 ttmp10, 0            /* Clear ttmp10 and ttmp11 */
> +  s_mov_b64 ttmp12, 0            /* Clear ttmp12 and ttmp13 */
> +  s_mov_b64 ttmp14, 0            /* Clear ttmp14 and ttmp15 */
>   s_endpgm
>   
>   label_0023:
>   
>     s_sethalt 1
>   
> -  s_mov_b32     m0, 0x0000005c   // Loop 96/4=24 times  (loop unrolled for performance)
> +  s_mov_b32     m0, 0x0000005c   /* Loop 128/8=16 times  (loop unrolled for performance) */
>     s_nop 0
>   label_sgpr_loop1:
>   
> @@ -143,10 +148,10 @@ label_sgpr_loop1:
>     s_sub_u32         m0, m0, 4
>     s_cbranch_scc0  label_sgpr_loop1
>    
> -  //clear vcc, flat scratch
> -  s_mov_b32 flat_scratch_lo, 0   //clear  flat scratch lo SGPR
> -  s_mov_b32 flat_scratch_hi, 0   //clear  flat scratch hi SGPR
> -  s_mov_b64 vcc, 0xee            //clear vcc
> +  /* clear vcc, flat scratch */
> +  s_mov_b32 flat_scratch_lo, 0   /* clear  flat scratch lo SGPR */
> +  s_mov_b32 flat_scratch_hi, 0   /* clear  flat scratch hi SGPR */
> +  s_mov_b64 vcc, 0xee            /* clear vcc */
>   
>   s_endpgm
>   end



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