L4Re Operating System Framework
Interface and Usage Documentation
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cpu.h
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1
7/*
8 * (c) 2004-2009 Author(s)
9 * economic rights: Technische Universität Dresden (Germany)
10 * This file is part of TUD:OS and distributed under the terms of the
11 * GNU Lesser General Public License 2.1.
12 * Please see the COPYING-LGPL-2.1 file for details.
13 */
14
15#ifndef __L4_UTIL_CPU_H
16#define __L4_UTIL_CPU_H
17
18#include <l4/sys/compiler.h>
19
21
34
41L4_INLINE unsigned int l4util_cpu_capabilities(void);
42
49
53L4_INLINE void
54l4util_cpu_cpuid(unsigned long mode,
55 unsigned long *eax, unsigned long *ebx,
56 unsigned long *ecx, unsigned long *edx);
57
59static inline void
60l4util_cpu_pause(void)
61{
62 __asm__ __volatile__ ("rep; nop");
63}
64
65L4_INLINE int
67{
68 return 1;
69}
70
71L4_INLINE void
72l4util_cpu_cpuid(unsigned long mode,
73 unsigned long *eax, unsigned long *ebx,
74 unsigned long *ecx, unsigned long *edx)
75{
76 asm volatile("cpuid"
77 : "=a" (*eax),
78 "=b" (*ebx),
79 "=c" (*ecx),
80 "=d" (*edx)
81 : "a" (mode)
82 );
83}
84
85L4_INLINE unsigned int
87{
88 unsigned long dummy, capability;
89
90 /* get CPU capabilities */
91 l4util_cpu_cpuid(1, &dummy, &dummy, &dummy, &capability);
92
93 return capability;
94}
95
96L4_INLINE unsigned int
98{
100 return 0; /* CPU has not cpuid instruction */
101
103}
104
106
107#endif
108
L4 compiler related defines.
#define L4_INLINE
L4 Inline function attribute.
Definition compiler.h:62
#define EXTERN_C_BEGIN
Start section with C types and functions.
Definition compiler.h:192
#define EXTERN_C_END
End section with C types and functions.
Definition compiler.h:193
void l4util_cpu_cpuid(unsigned long mode, unsigned long *eax, unsigned long *ebx, unsigned long *ecx, unsigned long *edx)
Generic CPUID access function.
Definition cpu.h:72
unsigned int l4util_cpu_capabilities_nocheck(void)
Returns the CPU capabilities.
Definition cpu.h:86
unsigned int l4util_cpu_capabilities(void)
Returns the CPU capabilities if the "cpuid" instruction is available.
Definition cpu.h:97
int l4util_cpu_has_cpuid(void)
Check whether the CPU supports the "cpuid" instruction.
Definition cpu.h:66