Files
foc/l4/pkg/l4util/include/util.h
2013-01-11 17:00:47 +01:00

93 lines
2.3 KiB
C

/**
* \file
* \brief Utilities, generic file
*/
/*
* (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
* Alexander Warg <warg@os.inf.tu-dresden.de>,
* Frank Mehnert <fm3@os.inf.tu-dresden.de>
* economic rights: Technische Universität Dresden (Germany)
* This file is part of TUD:OS and distributed under the terms of the
* GNU Lesser General Public License 2.1.
* Please see the COPYING-LGPL-2.1 file for details.
*/
#ifndef __L4UTIL__UTIL_H__
#define __L4UTIL__UTIL_H__
#include <l4/sys/types.h>
#include <l4/sys/compiler.h>
#include <l4/sys/ipc.h>
/**
* \defgroup l4util_api Utility Functions
*/
EXTERN_C_BEGIN
/**
* \brief Calculate l4 timeouts
* \ingroup l4util_api
* \param mus time in microseconds. Special cases:
* - 0 - > timeout 0
* - ~0U -> timeout NEVER
* \return the corresponding l4_timeout value
*/
L4_CV l4_timeout_s l4util_micros2l4to(unsigned int mus) L4_NOTHROW;
/** Suspend thread for a period of <ms> milliseconds */
L4_CV void l4_sleep(int ms) L4_NOTHROW;
/* \brief Suspend thread for a period of <us> micro seconds.
* \ingroup l4util_api
* WARNING: This function is mostly bogus since the timer resolution of
* current L4 implementations is about 1ms! */
L4_CV void l4_usleep(int us) L4_NOTHROW;
/**
* \brief Go sleep and never wake up.
* \ingroup l4util_api
*
*/
L4_INLINE void l4_sleep_forever(void) L4_NOTHROW __attribute__((noreturn));
L4_INLINE void
l4_sleep_forever(void) L4_NOTHROW
{
for (;;)
l4_ipc_sleep(L4_IPC_NEVER);
}
/** Touch data areas to force mapping read-only */
static inline void
l4_touch_ro(const void*addr, unsigned size) L4_NOTHROW
{
volatile const char *bptr, *eptr;
bptr = (const char*)(((unsigned)addr) & L4_PAGEMASK);
eptr = (const char*)(((unsigned)addr+size-1) & L4_PAGEMASK);
for(;bptr<=eptr;bptr+=L4_PAGESIZE) {
(void)(*bptr);
}
}
/** Touch data areas to force mapping read-write */
static inline void
l4_touch_rw(const void*addr, unsigned size) L4_NOTHROW
{
volatile char *bptr;
volatile const char *eptr;
bptr = (char*)(((unsigned)addr) & L4_PAGEMASK);
eptr = (const char*)(((unsigned)addr+size-1) & L4_PAGEMASK);
for(;bptr<=eptr;bptr+=L4_PAGESIZE) {
char x = *bptr;
*bptr = x;
}
}
EXTERN_C_END
#endif /* __L4UTIL__UTIL_H__ */