/*

 * Copyright © 2013-2016 Inria.  All rights reserved.

 * See COPYING in top-level directory.

 */

/** \file

 * \brief Macros to help interaction between hwloc and Intel Xeon Phi (MIC).

 *

 * Applications that use both hwloc and Intel Xeon Phi (MIC) may want to

 * include this file so as to get topology information for MIC devices.

 */

#ifndef HWLOC_INTEL_MIC_H

#define HWLOC_INTEL_MIC_H

#include <hwloc.h>

#include <hwloc/autogen/config.h>

#include <hwloc/helper.h>

#ifdef HWLOC_LINUX_SYS

#include <hwloc/linux.h>

#include <dirent.h>

#include <string.h>

#endif

#include <stdio.h>

#include <stdlib.h>

#ifdef __cplusplus

extern "C" {

#endif

/** \defgroup hwlocality_intel_mic Interoperability with Intel Xeon Phi (MIC)

 *

 * This interface offers ways to retrieve topology information about

 * Intel Xeon Phi (MIC) devices.

 *

 * @{

 */

/** \brief Get the CPU set of logical processors that are physically

 * close to MIC device whose index is \p idx.

 *

 * Return the CPU set describing the locality of the MIC device whose index is \p idx.

 *

 * Topology \p topology and device index \p idx must match the local machine.

 * I/O devices detection is 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_intel_mic_get_device_osdev_by_index().

 *

 * This function is currently only implemented in a meaningful way for

 * Linux; other systems will simply get a full cpuset.

 */

static __hwloc_inline int

hwloc_intel_mic_get_device_cpuset(hwloc_topology_t topology __hwloc_attribute_unused,

				  int idx __hwloc_attribute_unused,

				  hwloc_cpuset_t set)

{

#ifdef HWLOC_LINUX_SYS

	/* If we're on Linux, use the sysfs mechanism to get the local cpus */

#define HWLOC_INTEL_MIC_DEVICE_SYSFS_PATH_MAX 128

	char path[HWLOC_INTEL_MIC_DEVICE_SYSFS_PATH_MAX];

	DIR *sysdir = NULL;

	struct dirent *dirent;

	unsigned pcibus, pcidev, pcifunc;

	if (!hwloc_topology_is_thissystem(topology)) {

		errno = EINVAL;

		return -1;

	}

	sprintf(path, "/sys/class/mic/mic%d", idx);

	sysdir = opendir(path);

	if (!sysdir)

		return -1;

	while ((dirent = readdir(sysdir)) != NULL) {

		if (sscanf(dirent->d_name, "pci_%02x:%02x.%02x", &pcibus, &pcidev, &pcifunc) == 3) {

			sprintf(path, "/sys/class/mic/mic%d/pci_%02x:%02x.%02x/local_cpus", idx, 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));

			break;

		}

	}

	closedir(sysdir);

#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

 * MIC device for the given index.

 *

 * Return the OS device object describing the MIC device whose index is \p idx.

 * 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 must be enabled in the topology.

 *

 * \note The corresponding PCI device object can be obtained by looking

 * at the OS device parent object.

 */

static __hwloc_inline hwloc_obj_t

hwloc_intel_mic_get_device_osdev_by_index(hwloc_topology_t topology,

					  unsigned idx)

{

	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

		    && !strncmp("mic", osdev->name, 3)

		    && atoi(osdev->name + 3) == (int) idx)

                        return osdev;

        }

        return NULL;

}

/** @} */

#ifdef __cplusplus

} /* extern "C" */

#endif

#endif /* HWLOC_INTEL_MIC_H */