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/*
* Copyright © 2012-2018 Inria. All rights reserved.
* Copyright © 2013, 2018 Université Bordeaux. All right reserved.
* See COPYING in top-level directory.
*/
/** \file
* \brief Macros to help interaction between hwloc and the OpenCL interface.
*
* Applications that use both hwloc and OpenCL may want to
* include this file so as to get topology information for OpenCL devices.
*/
#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
/** \defgroup hwlocality_opencl Interoperability with OpenCL
*
* This interface offers ways to retrieve topology information about
* OpenCL devices.
*
* Only AMD and NVIDIA OpenCL implementations currently offer useful locality
* information about their devices.
*
* @{
*/
/** \brief Return the domain, bus and device IDs of the OpenCL device \p device.
*
* Device \p device must match the local machine.
*/
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;
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 */
*bus = (unsigned) amdtopo.pcie.bus;
*dev = (unsigned) amdtopo.pcie.device;
*func = (unsigned) 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) {
/* FIXME: PCI bus only uses 8bit, assume nvidia hardcodes the domain in higher bits */
*domain = nvbus >> 8;
*bus = nvbus & 0xff;
/* non-documented but used in many other projects */
*dev = nvslot >> 3;
*func = nvslot & 0x7;
return 0;
}
}
return -1;
}
/** \brief Get the CPU set of logical processors that are physically
* close to OpenCL device \p device.
*
* Return the CPU set describing the locality of the OpenCL device \p device.
*
* Topology \p topology and device \p device must match the local machine.
* I/O devices detection and the OpenCL component are not needed in the topology.
*
* The function only returns the locality of the device.
* If more information about the device is needed, OS objects should
* be used instead, see hwloc_opencl_get_device_osdev()
* and hwloc_opencl_get_device_osdev_by_index().
*
* This function is currently only implemented in a meaningful way for
* Linux with the AMD or NVIDIA OpenCL implementation; other systems will simply
* get a full cpuset.
*/
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;
}
/** \brief Get the hwloc OS device object corresponding to the
* OpenCL device for the given indexes.
*
* Return the OS device object describing the OpenCL device
* whose platform index is \p platform_index,
* and whose device index within this platform if \p device_index.
* Return NULL if there is none.
*
* The topology \p topology does not necessarily have to match the current
* machine. For instance the topology may be an XML import of a remote host.
* I/O devices detection and the OpenCL component must be enabled in the topology.
*
* \note The corresponding PCI device object can be obtained by looking
* at the OS device parent object (unless PCI devices are filtered out).
*/
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;
}
/** \brief Get the hwloc OS device object corresponding to OpenCL device \p deviceX.
*
* Use OpenCL device attributes to find the corresponding hwloc OS device object.
* Return NULL if there is none or if useful attributes are not available.
*
* This function currently only works on AMD and NVIDIA OpenCL devices that support
* relevant OpenCL extensions. hwloc_opencl_get_device_osdev_by_index()
* should be preferred whenever possible, i.e. when platform and device index
* are known.
*
* Topology \p topology and device \p device must match the local machine.
* I/O devices detection and the OpenCL component must be enabled in the topology.
* If not, the locality of the object may still be found using
* hwloc_opencl_get_device_cpuset().
*
* \note This function cannot work if PCI devices are filtered out.
*
* \note The corresponding hwloc PCI device may be found by looking
* at the result parent pointer (unless PCI devices are filtered out).
*/
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 */
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