opencl.h

/*
 * Copyright © 2012-2023 Inria.  All rights reserved.
 * Copyright © 2013, 2018 Université Bordeaux.  All right reserved.
 * See COPYING in top-level directory.
 */
 
#ifndef HWLOC_OPENCL_H
#define HWLOC_OPENCL_H
 
#include "hwloc.h"
#include "hwloc/autogen/config.h"
#include "hwloc/helper.h"
#ifdef HWLOC_LINUX_SYS
#include "hwloc/linux.h"
#endif
 
#ifdef __APPLE__
#include <OpenCL/cl.h>
#else
#include <CL/cl.h>
#endif
 
#include <stdio.h>
 
 
#ifdef __cplusplus
extern "C" {
#endif
 
 
/* OpenCL extensions aren't always shipped with default headers, and
 * they don't always reflect what the installed implementations support.
 * Try everything and let the implementation return errors when non supported.
 */
/* Copyright (c) 2008-2018 The Khronos Group Inc. */
 
/* needs "cl_amd_device_attribute_query" device extension, but not strictly required for clGetDeviceInfo() */
#define HWLOC_CL_DEVICE_TOPOLOGY_AMD 0x4037
typedef union {
    struct { cl_uint type; cl_uint data[5]; } raw;
    struct { cl_uint type; cl_char unused[17]; cl_char bus; cl_char device; cl_char function; } pcie;
} hwloc_cl_device_topology_amd;
#define HWLOC_CL_DEVICE_TOPOLOGY_TYPE_PCIE_AMD 1
 
/* needs "cl_nv_device_attribute_query" device extension, but not strictly required for clGetDeviceInfo() */
#define HWLOC_CL_DEVICE_PCI_BUS_ID_NV 0x4008
#define HWLOC_CL_DEVICE_PCI_SLOT_ID_NV 0x4009
#define HWLOC_CL_DEVICE_PCI_DOMAIN_ID_NV 0x400A
 
 
static __hwloc_inline int
hwloc_opencl_get_device_pci_busid(cl_device_id device,
                               unsigned *domain, unsigned *bus, unsigned *dev, unsigned *func)
{
        hwloc_cl_device_topology_amd amdtopo;
        cl_uint nvbus, nvslot, nvdomain;
        cl_int clret;
 
        clret = clGetDeviceInfo(device, HWLOC_CL_DEVICE_TOPOLOGY_AMD, sizeof(amdtopo), &amdtopo, NULL);
        if (CL_SUCCESS == clret
            && HWLOC_CL_DEVICE_TOPOLOGY_TYPE_PCIE_AMD == amdtopo.raw.type) {
                *domain = 0; /* can't do anything better */
                /* cl_device_topology_amd stores bus ID in cl_char, dont convert those signed char directly to unsigned int */
                *bus = (unsigned) (unsigned char) amdtopo.pcie.bus;
                *dev = (unsigned) (unsigned char) amdtopo.pcie.device;
                *func = (unsigned) (unsigned char) amdtopo.pcie.function;
                return 0;
        }
 
        clret = clGetDeviceInfo(device, HWLOC_CL_DEVICE_PCI_BUS_ID_NV, sizeof(nvbus), &nvbus, NULL);
        if (CL_SUCCESS == clret) {
                clret = clGetDeviceInfo(device, HWLOC_CL_DEVICE_PCI_SLOT_ID_NV, sizeof(nvslot), &nvslot, NULL);
                if (CL_SUCCESS == clret) {
                        clret = clGetDeviceInfo(device, HWLOC_CL_DEVICE_PCI_DOMAIN_ID_NV, sizeof(nvdomain), &nvdomain, NULL);
                        if (CL_SUCCESS == clret) { /* available since CUDA 10.2 */
                                *domain = nvdomain;
                        } else {
                                *domain = 0;
                        }
                        *bus = nvbus & 0xff;
                        /* non-documented but used in many other projects */
                        *dev = nvslot >> 3;
                        *func = nvslot & 0x7;
                        return 0;
                }
        }
 
        return -1;
}
 
static __hwloc_inline int
hwloc_opencl_get_device_cpuset(hwloc_topology_t topology __hwloc_attribute_unused,
                               cl_device_id device __hwloc_attribute_unused,
                               hwloc_cpuset_t set)
{
#if (defined HWLOC_LINUX_SYS)
        /* If we're on Linux, try AMD/NVIDIA extensions + the sysfs mechanism to get the local cpus */
#define HWLOC_OPENCL_DEVICE_SYSFS_PATH_MAX 128
        char path[HWLOC_OPENCL_DEVICE_SYSFS_PATH_MAX];
        unsigned pcidomain, pcibus, pcidev, pcifunc;
 
        if (!hwloc_topology_is_thissystem(topology)) {
                errno = EINVAL;
                return -1;
        }
 
        if (hwloc_opencl_get_device_pci_busid(device, &pcidomain, &pcibus, &pcidev, &pcifunc) < 0) {
                hwloc_bitmap_copy(set, hwloc_topology_get_complete_cpuset(topology));
                return 0;
        }
 
        sprintf(path, "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/local_cpus", pcidomain, pcibus, pcidev, pcifunc);
        if (hwloc_linux_read_path_as_cpumask(path, set) < 0
            || hwloc_bitmap_iszero(set))
                hwloc_bitmap_copy(set, hwloc_topology_get_complete_cpuset(topology));
#else
        /* Non-Linux systems simply get a full cpuset */
        hwloc_bitmap_copy(set, hwloc_topology_get_complete_cpuset(topology));
#endif
  return 0;
}
 
static __hwloc_inline hwloc_obj_t
hwloc_opencl_get_device_osdev_by_index(hwloc_topology_t topology,
                                       unsigned platform_index, unsigned device_index)
{
        unsigned x = (unsigned) -1, y = (unsigned) -1;
        hwloc_obj_t osdev = NULL;
        while ((osdev = hwloc_get_next_osdev(topology, osdev)) != NULL) {
                if (HWLOC_OBJ_OSDEV_COPROC == osdev->attr->osdev.type
                    && osdev->name
                    && sscanf(osdev->name, "opencl%ud%u", &x, &y) == 2
                    && platform_index == x && device_index == y)
                        return osdev;
        }
        return NULL;
}
 
static __hwloc_inline hwloc_obj_t
hwloc_opencl_get_device_osdev(hwloc_topology_t topology __hwloc_attribute_unused,
                              cl_device_id device __hwloc_attribute_unused)
{
        hwloc_obj_t osdev;
        unsigned pcidomain, pcibus, pcidevice, pcifunc;
 
        if (hwloc_opencl_get_device_pci_busid(device, &pcidomain, &pcibus, &pcidevice, &pcifunc) < 0) {
                errno = EINVAL;
                return NULL;
        }
 
        osdev = NULL;
        while ((osdev = hwloc_get_next_osdev(topology, osdev)) != NULL) {
                hwloc_obj_t pcidev = osdev->parent;
                if (strncmp(osdev->name, "opencl", 6))
                        continue;
                if (pcidev
                    && pcidev->type == HWLOC_OBJ_PCI_DEVICE
                    && pcidev->attr->pcidev.domain == pcidomain
                    && pcidev->attr->pcidev.bus == pcibus
                    && pcidev->attr->pcidev.dev == pcidevice
                    && pcidev->attr->pcidev.func == pcifunc)
                        return osdev;
                /* if PCI are filtered out, we need a info attr to match on */
        }
 
        return NULL;
}
 
#ifdef __cplusplus
} /* extern "C" */
#endif
 
 
#endif /* HWLOC_OPENCL_H */