• C
    arch/tile: Add driver to enable access to the user dynamic network. · 9f9c0382
    Chris Metcalf 提交于
    This network (the "UDN") connects all the cpus on the chip in a
    wormhole-routed dynamic network.  Subrectangles of the chip can
    be allocated by a "create" ioctl on /dev/hardwall, and then to access the
    UDN in that rectangle, tasks must perform an "activate" ioctl on that
    same file object after affinitizing themselves to a single cpu in
    the region.  Sending a wormhole-routed message that tries to leave
    that subrectangle causes all activated tasks to receive a SIGILL
    (just as they would if they tried to access the UDN without first
    activating themselves to a hardwall rectangle).
    
    The original submission of this code to LKML had the driver
    instantiated under /proc/tile/hardwall.  Now we just use a character
    device for this, conventionally /dev/hardwall.  Some futures planning
    for the TILE-Gx chip suggests that we may want to have other types of
    devices that share the general model of "bind a task to a cpu, then
    'activate' a file descriptor on a pseudo-device that gives access to
    some hardware resource".  As such, we are using a device rather
    than, for example, a syscall, to set up and activate this code.
    
    As part of this change, the compat_ptr() declaration was fixed and used
    to pass the compat_ioctl argument to the normal ioctl.  So far we limit
    compat code to 2GB, so the difference between zero-extend and sign-extend
    (the latter being correct, eventually) had been overlooked.
    Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
    Acked-by: NArnd Bergmann <arnd@arndb.de>
    9f9c0382
hardwall.h 1.6 KB
/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 *
 * Provide methods for the HARDWALL_FILE for accessing the UDN.
 */

#ifndef _ASM_TILE_HARDWALL_H
#define _ASM_TILE_HARDWALL_H

#include <linux/ioctl.h>

#define HARDWALL_IOCTL_BASE 0xa2

/*
 * The HARDWALL_CREATE() ioctl is a macro with a "size" argument.
 * The resulting ioctl value is passed to the kernel in conjunction
 * with a pointer to a little-endian bitmask of cpus, which must be
 * physically in a rectangular configuration on the chip.
 * The "size" is the number of bytes of cpu mask data.
 */
#define _HARDWALL_CREATE 1
#define HARDWALL_CREATE(size) \
  _IOC(_IOC_READ, HARDWALL_IOCTL_BASE, _HARDWALL_CREATE, (size))

#define _HARDWALL_ACTIVATE 2
#define HARDWALL_ACTIVATE \
  _IO(HARDWALL_IOCTL_BASE, _HARDWALL_ACTIVATE)

#define _HARDWALL_DEACTIVATE 3
#define HARDWALL_DEACTIVATE \
 _IO(HARDWALL_IOCTL_BASE, _HARDWALL_DEACTIVATE)

#ifndef __KERNEL__

/* This is the canonical name expected by userspace. */
#define HARDWALL_FILE "/dev/hardwall"

#else

/* Hook for /proc/tile/hardwall. */
struct seq_file;
int proc_tile_hardwall_show(struct seq_file *sf, void *v);

#endif

#endif /* _ASM_TILE_HARDWALL_H */
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