/*

 * Copyright © 2012 Blue Brain Project, EPFL. All rights reserved.

 * Copyright © 2012-2013 Inria.  All rights reserved.

 * See COPYING in top-level directory.

 */

/** \file

 * \brief Macros to help interaction between hwloc and OpenGL displays.

 *

 * Applications that use both hwloc and OpenGL may want to include

 * this file so as to get topology information for OpenGL displays.

 */

#ifndef HWLOC_GL_H

#define HWLOC_GL_H

#include <hwloc.h>

#include <stdio.h>

#include <string.h>

#ifdef __cplusplus

extern "C" {

#endif

/** \defgroup hwlocality_gl Interoperability with OpenGL displays

 *

 * This interface offers ways to retrieve topology information about

 * OpenGL displays.

 *

 * Only the NVIDIA display locality information is currently available,

 * using the NV-CONTROL X11 extension and the NVCtrl library.

 *

 * @{

 */

/** \brief Get the hwloc OS device object corresponding to the

 * OpenGL display given by port and device index.

 *

 * Return the OS device object describing the OpenGL display

 * whose port (server) is \p port and device (screen) is \p device.

 * 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 GL 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_gl_get_display_osdev_by_port_device(hwloc_topology_t topology,

					  unsigned port, unsigned device)

{

        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_GPU == osdev->attr->osdev.type

                    && osdev->name

                    && sscanf(osdev->name, ":%u.%u", &x, &y) == 2

                    && port == x && device == y)

                        return osdev;

        }

	errno = EINVAL;

        return NULL;

}

/** \brief Get the hwloc OS device object corresponding to the

 * OpenGL display given by name.

 *

 * Return the OS device object describing the OpenGL display

 * whose name is \p name, built as ":port.device" such as ":0.0" .

 * 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 GL 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_gl_get_display_osdev_by_name(hwloc_topology_t topology,

				   const char *name)

{

        hwloc_obj_t osdev = NULL;

        while ((osdev = hwloc_get_next_osdev(topology, osdev)) != NULL) {

                if (HWLOC_OBJ_OSDEV_GPU == osdev->attr->osdev.type

                    && osdev->name

                    && !strcmp(name, osdev->name))

                        return osdev;

        }

	errno = EINVAL;

        return NULL;

}

/** \brief Get the OpenGL display port and device corresponding

 * to the given hwloc OS object.

 *

 * Return the OpenGL display port (server) in \p port and device (screen)

 * in \p screen that correspond to the given hwloc OS device object.

 * Return \c -1 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 GL component must be enabled in the topology.

 */

static __hwloc_inline int

hwloc_gl_get_display_by_osdev(hwloc_topology_t topology __hwloc_attribute_unused,

			      hwloc_obj_t osdev,

			      unsigned *port, unsigned *device)

{

	unsigned x = -1, y = -1;

	if (HWLOC_OBJ_OSDEV_GPU == osdev->attr->osdev.type

	    && sscanf(osdev->name, ":%u.%u", &x, &y) == 2) {

		*port = x;

		*device = y;

		return 0;

	}

	errno = EINVAL;

	return -1;

}

/** @} */

#ifdef __cplusplus

} /* extern "C" */

#endif

#endif /* HWLOC_GL_H */