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linux/arch/tile/include/asm/hardwall.h
Chris Metcalf 9f9c0382cd arch/tile: Add driver to enable access to the user dynamic network.
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: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2010-07-06 13:34:15 -04:00

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1.6 KiB
C

/*
* 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 */