workgroup_barrier.hpp Source File

workgroup_barrier.hpp Source File#

Composable Kernel: workgroup_barrier.hpp Source File
// SPDX-License-Identifier: MIT
// Copyright (c) 2018-2025, Advanced Micro Devices, Inc. All rights reserved.
 
#pragma once
 
#include "ck_tile/core/config.hpp"
#include "ck_tile/core/numeric/integer.hpp"
 
namespace ck_tile {
 
struct workgroup_barrier
{
    CK_TILE_DEVICE workgroup_barrier(uint32_t* ptr) : base_ptr(ptr) {}
 
    CK_TILE_DEVICE uint32_t ld(uint32_t offset = 0)
    {
        return __atomic_load_n(base_ptr + offset, __ATOMIC_RELAXED);
    }
 
    CK_TILE_DEVICE void wait_eq(uint32_t value, uint32_t offset = 0)
    {
        if(threadIdx.x == 0)
        {
            while(ld(offset) != value) {}
        }
        __syncthreads();
    }
 
    CK_TILE_DEVICE void wait_lt(uint32_t value, uint32_t offset = 0)
    {
        if(threadIdx.x == 0)
        {
            while(ld(offset) < value) {}
        }
        __syncthreads();
    }
 
    CK_TILE_DEVICE void wait_set(uint32_t compare, uint32_t value, uint32_t offset = 0)
    {
        if(threadIdx.x == 0)
        {
            while(atomicCAS(base_ptr + offset, compare, value) != compare) {}
        }
        __syncthreads();
    }
 
    // enter critical zoon, assume buffer is zero when launch kernel
    CK_TILE_DEVICE void aquire(uint32_t offset = 0) { wait_set(offset, 0, 1); }
 
    // exit critical zoon, assume buffer is zero when launch kernel
    CK_TILE_DEVICE void release(uint32_t offset = 0) { wait_set(offset, 1, 0); }
 
    CK_TILE_DEVICE void inc(uint32_t offset = 0)
    {
        __syncthreads();
        if(threadIdx.x == 0)
        {
            atomicAdd(base_ptr + offset, 1);
        }
    }
 
    uint32_t* base_ptr;
};
 
} // namespace ck_tile