1 /**
2  * \file
3  * \brief Utilities for x86
4  */
5 /*
6  * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
7  *               Alexander Warg <warg@os.inf.tu-dresden.de>,
8  *               Frank Mehnert <fm3@os.inf.tu-dresden.de>,
9  *               Jork Löser <jork@os.inf.tu-dresden.de>
10  *     economic rights: Technische Universität Dresden (Germany)
11  * This file is part of TUD:OS and distributed under the terms of the
12  * GNU Lesser General Public License 2.1.
13  * Please see the COPYING-LGPL-2.1 file for details.
14  */
15 #ifndef __UTIL_H
16 #define __UTIL_H
17 
18 #include <l4/sys/types.h>
19 #include <l4/sys/compiler.h>
20 #include <l4/sys/ipc.h>
21 
22 EXTERN_C_BEGIN
23 
24 /** Calculate l4 timeouts
25  * \param mus	time in microseconds. Special cases:
26  *		- 0 - > timeout 0
27  *		- ~0U -> timeout NEVER
28  * \return the corresponding l4_timeout value
29  */
30 L4_CV l4_timeout_s l4util_micros2l4to(unsigned int mus) L4_NOTHROW;
31 
32 /** Suspend thread for a period of \a ms milliseconds
33  * \param ms Time in milliseconds
34  */
35 L4_CV void l4_sleep(int ms) L4_NOTHROW;
36 
37 /* Suspend thread for a period of \a us microseconds.
38  * \param us Time in microseconds
39  * WARNING: This function is mostly bogus since the timer resolution of
40  *          current L4 implementations is about 1ms! */
41 L4_CV void l4_usleep(int us) L4_NOTHROW;
42 
43 /**
44  * \brief Go sleep and never wake up.
45  * \ingroup l4util_api
46  *
47  */
48 L4_INLINE void l4_sleep_forever(void) L4_NOTHROW __attribute__((noreturn));
49 
50 L4_INLINE void
l4_sleep_forever(void)51 l4_sleep_forever(void) L4_NOTHROW
52 {
53   for (;;)
54     l4_ipc_sleep(L4_IPC_NEVER);
55 }
56 
57 /** Touch data areas to force mapping read-only */
58 static inline void
l4_touch_ro(const void * addr,unsigned size)59 l4_touch_ro(const void*addr, unsigned size) L4_NOTHROW
60 {
61   const char *bptr, *eptr;
62 
63   bptr = (const char*)(((l4_addr_t)addr) & L4_PAGEMASK);
64   eptr = (const char*)(((l4_addr_t)addr+size-1) & L4_PAGEMASK);
65   for(;bptr<=eptr;bptr+=L4_PAGESIZE){
66     asm volatile("or	%0,%%eax \n"
67                  :
68                  : "m" (*(const unsigned*)bptr)
69                  : "eax" );
70   }
71 }
72 
73 
74 /** Touch data areas to force mapping read-write */
75 static inline void
l4_touch_rw(const void * addr,unsigned size)76 l4_touch_rw(const void*addr, unsigned size) L4_NOTHROW
77 {
78   const char *bptr, *eptr;
79 
80   bptr = (const char*)(((l4_addr_t)addr) & L4_PAGEMASK);
81   eptr = (const char*)(((l4_addr_t)addr+size-1) & L4_PAGEMASK);
82   for(;bptr<=eptr;bptr+=L4_PAGESIZE){
83     asm volatile("orb	$0,%0 \n"
84                  :
85                  : "m" (*(const unsigned*)bptr)
86                  );
87   }
88 }
89 
90 EXTERN_C_END
91 
92 #endif
93 
94