Input: update some documentation
[linux-2.6] / include / asm-arm26 / system.h
1 #ifndef __ASM_ARM_SYSTEM_H
2 #define __ASM_ARM_SYSTEM_H
3
4 #ifdef __KERNEL__
5
6
7 /*
8  * This is used to ensure the compiler did actually allocate the register we
9  * asked it for some inline assembly sequences.  Apparently we can't trust
10  * the compiler from one version to another so a bit of paranoia won't hurt.
11  * This string is meant to be concatenated with the inline asm string and
12  * will cause compilation to stop on mismatch. (From ARM32 - may come in handy)
13  */
14 #define __asmeq(x, y)  ".ifnc " x "," y " ; .err ; .endif\n\t"
15
16 #ifndef __ASSEMBLY__
17
18 #include <linux/linkage.h>
19
20 struct thread_info;
21 struct task_struct;
22
23 #if 0
24 /* information about the system we're running on */
25 extern unsigned int system_rev;
26 extern unsigned int system_serial_low;
27 extern unsigned int system_serial_high;
28 extern unsigned int mem_fclk_21285;
29
30 FIXME - sort this
31 /*
32  * We need to turn the caches off before calling the reset vector - RiscOS
33  * messes up if we don't
34  */
35 #define proc_hard_reset()       cpu_proc_fin()
36
37 #endif
38
39 struct pt_regs;
40
41 void die(const char *msg, struct pt_regs *regs, int err)
42                 __attribute__((noreturn));
43
44 void die_if_kernel(const char *str, struct pt_regs *regs, int err);
45
46 void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
47                                        struct pt_regs *),
48                      int sig, const char *name);
49
50 #include <asm/proc-fns.h>
51
52 #define xchg(ptr,x) \
53         ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
54
55 #define tas(ptr) (xchg((ptr),1))
56
57 extern asmlinkage void __backtrace(void);
58
59 #define set_cr(x)                                       \
60         __asm__ __volatile__(                           \
61         "mcr    p15, 0, %0, c1, c0, 0   @ set CR"       \
62         : : "r" (x) : "cc")
63
64 #define get_cr()                                        \
65         ({                                              \
66         unsigned int __val;                             \
67         __asm__ __volatile__(                           \
68         "mrc    p15, 0, %0, c1, c0, 0   @ get CR"       \
69         : "=r" (__val) : : "cc");                       \
70         __val;                                          \
71         })
72
73 extern unsigned long cr_no_alignment;   /* defined in entry-armv.S */
74 extern unsigned long cr_alignment;      /* defined in entry-armv.S */
75
76 #define UDBG_UNDEFINED  (1 << 0)
77 #define UDBG_SYSCALL    (1 << 1)
78 #define UDBG_BADABORT   (1 << 2)
79 #define UDBG_SEGV       (1 << 3)
80 #define UDBG_BUS        (1 << 4)
81
82 extern unsigned int user_debug;
83
84 #define vectors_base()  (0)
85
86 #define mb() __asm__ __volatile__ ("" : : : "memory")
87 #define rmb() mb()
88 #define wmb() mb()
89 #define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t");
90
91 #define read_barrier_depends() do { } while(0)
92 #define set_mb(var, value)  do { var = value; mb(); } while (0)
93
94 /*
95  * We assume knowledge of how
96  * spin_unlock_irq() and friends are implemented.  This avoids
97  * us needlessly decrementing and incrementing the preempt count.
98  */
99 #define prepare_arch_switch(next)       local_irq_enable()
100 #define finish_arch_switch(prev)        spin_unlock(&(rq)->lock)
101
102 /*
103  * switch_to(prev, next) should switch from task `prev' to `next'
104  * `prev' will never be the same as `next'.  schedule() itself
105  * contains the memory barrier to tell GCC not to cache `current'.
106  */
107 extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
108
109 #define switch_to(prev,next,last)                                       \
110 do {                                                                    \
111         last = __switch_to(prev,task_thread_info(prev),task_thread_info(next)); \
112 } while (0)
113
114 /*
115  * On SMP systems, when the scheduler does migration-cost autodetection,
116  * it needs a way to flush as much of the CPU's caches as possible.
117  *
118  * TODO: fill this in!
119  */
120 static inline void sched_cacheflush(void)
121 {
122 }
123
124 /*
125  * Save the current interrupt enable state & disable IRQs
126  */
127 #define local_irq_save(x)                               \
128         do {                                            \
129           unsigned long temp;                           \
130           __asm__ __volatile__(                         \
131 "       mov     %0, pc          @ save_flags_cli\n"     \
132 "       orr     %1, %0, #0x08000000\n"                  \
133 "       and     %0, %0, #0x0c000000\n"                  \
134 "       teqp    %1, #0\n"                               \
135           : "=r" (x), "=r" (temp)                       \
136           :                                             \
137           : "memory");                                  \
138         } while (0)
139
140 /*
141  * Enable IRQs  (sti)
142  */
143 #define local_irq_enable()                                      \
144         do {                                    \
145           unsigned long temp;                   \
146           __asm__ __volatile__(                 \
147 "       mov     %0, pc          @ sti\n"        \
148 "       bic     %0, %0, #0x08000000\n"          \
149 "       teqp    %0, #0\n"                       \
150           : "=r" (temp)                         \
151           :                                     \
152           : "memory");                          \
153         } while(0)
154
155 /*
156  * Disable IRQs (cli)
157  */
158 #define local_irq_disable()                                     \
159         do {                                    \
160           unsigned long temp;                   \
161           __asm__ __volatile__(                 \
162 "       mov     %0, pc          @ cli\n"        \
163 "       orr     %0, %0, #0x08000000\n"          \
164 "       teqp    %0, #0\n"                       \
165           : "=r" (temp)                         \
166           :                                     \
167           : "memory");                          \
168         } while(0)
169
170 /* Enable FIQs (stf) */
171
172 #define __stf() do {                            \
173         unsigned long temp;                     \
174         __asm__ __volatile__(                   \
175 "       mov     %0, pc          @ stf\n"        \
176 "       bic     %0, %0, #0x04000000\n"          \
177 "       teqp    %0, #0\n"                       \
178         : "=r" (temp));                         \
179     } while(0)
180
181 /* Disable FIQs  (clf) */
182
183 #define __clf() do {                            \
184         unsigned long temp;                     \
185         __asm__ __volatile__(                   \
186 "       mov     %0, pc          @ clf\n"        \
187 "       orr     %0, %0, #0x04000000\n"          \
188 "       teqp    %0, #0\n"                       \
189         : "=r" (temp));                         \
190     } while(0)
191
192
193 /*
194  * Save the current interrupt enable state.
195  */
196 #define local_save_flags(x)                             \
197         do {                                    \
198           __asm__ __volatile__(                 \
199 "       mov     %0, pc          @ save_flags\n" \
200 "       and     %0, %0, #0x0c000000\n"          \
201           : "=r" (x));                          \
202         } while (0)
203
204
205 /*
206  * restore saved IRQ & FIQ state
207  */
208 #define local_irq_restore(x)                            \
209         do {                                            \
210           unsigned long temp;                           \
211           __asm__ __volatile__(                         \
212 "       mov     %0, pc          @ restore_flags\n"      \
213 "       bic     %0, %0, #0x0c000000\n"                  \
214 "       orr     %0, %0, %1\n"                           \
215 "       teqp    %0, #0\n"                               \
216           : "=&r" (temp)                                \
217           : "r" (x)                                     \
218           : "memory");                                  \
219         } while (0)
220
221
222 #ifdef CONFIG_SMP
223 #error SMP not supported
224 #endif
225
226 #define smp_mb()                barrier()
227 #define smp_rmb()               barrier()
228 #define smp_wmb()               barrier()
229 #define smp_read_barrier_depends()              do { } while(0)
230
231 #define clf()                   __clf()
232 #define stf()                   __stf()
233
234 #define irqs_disabled()                 \
235 ({                                      \
236         unsigned long flags;            \
237         local_save_flags(flags);        \
238         flags & PSR_I_BIT;              \
239 })
240
241 static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
242 {
243         extern void __bad_xchg(volatile void *, int);
244
245         switch (size) {
246                 case 1: return cpu_xchg_1(x, ptr);
247                 case 4: return cpu_xchg_4(x, ptr);
248                 default: __bad_xchg(ptr, size);
249         }
250         return 0;
251 }
252
253 #endif /* __ASSEMBLY__ */
254
255 #define arch_align_stack(x) (x)
256
257 #endif /* __KERNEL__ */
258
259 #endif