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1 | /* |
2 | * This file is subject to the terms and conditions of the GNU General Public | |
3 | * License. See the file "COPYING" in the main directory of this archive | |
4 | * for more details. | |
5 | * | |
6 | * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 by Ralf Baechle | |
7 | * Copyright (C) 1996 by Paul M. Antoine | |
8 | * Copyright (C) 1999 Silicon Graphics | |
9 | * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com | |
10 | * Copyright (C) 2000 MIPS Technologies, Inc. | |
11 | */ | |
12 | #ifndef _ASM_SYSTEM_H | |
13 | #define _ASM_SYSTEM_H | |
14 | ||
15 | #include <linux/config.h> | |
16 | #include <linux/types.h> | |
17 | ||
18 | #include <asm/addrspace.h> | |
19 | #include <asm/cpu-features.h> | |
20 | #include <asm/ptrace.h> | |
21 | #include <asm/war.h> | |
22 | #include <asm/interrupt.h> | |
23 | ||
24 | /* | |
25 | * read_barrier_depends - Flush all pending reads that subsequents reads | |
26 | * depend on. | |
27 | * | |
28 | * No data-dependent reads from memory-like regions are ever reordered | |
29 | * over this barrier. All reads preceding this primitive are guaranteed | |
30 | * to access memory (but not necessarily other CPUs' caches) before any | |
31 | * reads following this primitive that depend on the data return by | |
32 | * any of the preceding reads. This primitive is much lighter weight than | |
33 | * rmb() on most CPUs, and is never heavier weight than is | |
34 | * rmb(). | |
35 | * | |
36 | * These ordering constraints are respected by both the local CPU | |
37 | * and the compiler. | |
38 | * | |
39 | * Ordering is not guaranteed by anything other than these primitives, | |
40 | * not even by data dependencies. See the documentation for | |
41 | * memory_barrier() for examples and URLs to more information. | |
42 | * | |
43 | * For example, the following code would force ordering (the initial | |
44 | * value of "a" is zero, "b" is one, and "p" is "&a"): | |
45 | * | |
46 | * <programlisting> | |
47 | * CPU 0 CPU 1 | |
48 | * | |
49 | * b = 2; | |
50 | * memory_barrier(); | |
51 | * p = &b; q = p; | |
52 | * read_barrier_depends(); | |
53 | * d = *q; | |
54 | * </programlisting> | |
55 | * | |
56 | * because the read of "*q" depends on the read of "p" and these | |
57 | * two reads are separated by a read_barrier_depends(). However, | |
58 | * the following code, with the same initial values for "a" and "b": | |
59 | * | |
60 | * <programlisting> | |
61 | * CPU 0 CPU 1 | |
62 | * | |
63 | * a = 2; | |
64 | * memory_barrier(); | |
65 | * b = 3; y = b; | |
66 | * read_barrier_depends(); | |
67 | * x = a; | |
68 | * </programlisting> | |
69 | * | |
70 | * does not enforce ordering, since there is no data dependency between | |
71 | * the read of "a" and the read of "b". Therefore, on some CPUs, such | |
72 | * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb() | |
73 | * in cases like thiswhere there are no data dependencies. | |
74 | */ | |
75 | ||
76 | #define read_barrier_depends() do { } while(0) | |
77 | ||
78 | #ifdef CONFIG_CPU_HAS_SYNC | |
79 | #define __sync() \ | |
80 | __asm__ __volatile__( \ | |
81 | ".set push\n\t" \ | |
82 | ".set noreorder\n\t" \ | |
83 | ".set mips2\n\t" \ | |
84 | "sync\n\t" \ | |
85 | ".set pop" \ | |
86 | : /* no output */ \ | |
87 | : /* no input */ \ | |
88 | : "memory") | |
89 | #else | |
90 | #define __sync() do { } while(0) | |
91 | #endif | |
92 | ||
93 | #define __fast_iob() \ | |
94 | __asm__ __volatile__( \ | |
95 | ".set push\n\t" \ | |
96 | ".set noreorder\n\t" \ | |
97 | "lw $0,%0\n\t" \ | |
98 | "nop\n\t" \ | |
99 | ".set pop" \ | |
100 | : /* no output */ \ | |
101 | : "m" (*(int *)CKSEG1) \ | |
102 | : "memory") | |
103 | ||
104 | #define fast_wmb() __sync() | |
105 | #define fast_rmb() __sync() | |
106 | #define fast_mb() __sync() | |
107 | #define fast_iob() \ | |
108 | do { \ | |
109 | __sync(); \ | |
110 | __fast_iob(); \ | |
111 | } while (0) | |
112 | ||
113 | #ifdef CONFIG_CPU_HAS_WB | |
114 | ||
115 | #include <asm/wbflush.h> | |
116 | ||
117 | #define wmb() fast_wmb() | |
118 | #define rmb() fast_rmb() | |
119 | #define mb() wbflush() | |
120 | #define iob() wbflush() | |
121 | ||
122 | #else /* !CONFIG_CPU_HAS_WB */ | |
123 | ||
124 | #define wmb() fast_wmb() | |
125 | #define rmb() fast_rmb() | |
126 | #define mb() fast_mb() | |
127 | #define iob() fast_iob() | |
128 | ||
129 | #endif /* !CONFIG_CPU_HAS_WB */ | |
130 | ||
131 | #ifdef CONFIG_SMP | |
132 | #define smp_mb() mb() | |
133 | #define smp_rmb() rmb() | |
134 | #define smp_wmb() wmb() | |
135 | #define smp_read_barrier_depends() read_barrier_depends() | |
136 | #else | |
137 | #define smp_mb() barrier() | |
138 | #define smp_rmb() barrier() | |
139 | #define smp_wmb() barrier() | |
140 | #define smp_read_barrier_depends() do { } while(0) | |
141 | #endif | |
142 | ||
143 | #define set_mb(var, value) \ | |
144 | do { var = value; mb(); } while (0) | |
145 | ||
146 | #define set_wmb(var, value) \ | |
147 | do { var = value; wmb(); } while (0) | |
148 | ||
149 | /* | |
150 | * switch_to(n) should switch tasks to task nr n, first | |
151 | * checking that n isn't the current task, in which case it does nothing. | |
152 | */ | |
153 | extern asmlinkage void *resume(void *last, void *next, void *next_ti); | |
154 | ||
155 | struct task_struct; | |
156 | ||
157 | #define switch_to(prev,next,last) \ | |
158 | do { \ | |
159 | (last) = resume(prev, next, next->thread_info); \ | |
160 | } while(0) | |
161 | ||
162 | #define ROT_IN_PIECES \ | |
163 | " .set noreorder \n" \ | |
164 | " .set reorder \n" | |
165 | ||
166 | static inline unsigned long __xchg_u32(volatile int * m, unsigned int val) | |
167 | { | |
168 | __u32 retval; | |
169 | ||
170 | if (cpu_has_llsc && R10000_LLSC_WAR) { | |
171 | unsigned long dummy; | |
172 | ||
173 | __asm__ __volatile__( | |
174 | "1: ll %0, %3 # xchg_u32 \n" | |
175 | " move %2, %z4 \n" | |
176 | " sc %2, %1 \n" | |
177 | " beqzl %2, 1b \n" | |
178 | ROT_IN_PIECES | |
179 | #ifdef CONFIG_SMP | |
180 | " sync \n" | |
181 | #endif | |
182 | : "=&r" (retval), "=m" (*m), "=&r" (dummy) | |
183 | : "R" (*m), "Jr" (val) | |
184 | : "memory"); | |
185 | } else if (cpu_has_llsc) { | |
186 | unsigned long dummy; | |
187 | ||
188 | __asm__ __volatile__( | |
189 | "1: ll %0, %3 # xchg_u32 \n" | |
190 | " move %2, %z4 \n" | |
191 | " sc %2, %1 \n" | |
192 | " beqz %2, 1b \n" | |
193 | #ifdef CONFIG_SMP | |
194 | " sync \n" | |
195 | #endif | |
196 | : "=&r" (retval), "=m" (*m), "=&r" (dummy) | |
197 | : "R" (*m), "Jr" (val) | |
198 | : "memory"); | |
199 | } else { | |
200 | unsigned long flags; | |
201 | ||
202 | local_irq_save(flags); | |
203 | retval = *m; | |
204 | *m = val; | |
205 | local_irq_restore(flags); /* implies memory barrier */ | |
206 | } | |
207 | ||
208 | return retval; | |
209 | } | |
210 | ||
211 | #ifdef CONFIG_MIPS64 | |
212 | static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val) | |
213 | { | |
214 | __u64 retval; | |
215 | ||
216 | if (cpu_has_llsc && R10000_LLSC_WAR) { | |
217 | unsigned long dummy; | |
218 | ||
219 | __asm__ __volatile__( | |
220 | "1: lld %0, %3 # xchg_u64 \n" | |
221 | " move %2, %z4 \n" | |
222 | " scd %2, %1 \n" | |
223 | " beqzl %2, 1b \n" | |
224 | ROT_IN_PIECES | |
225 | #ifdef CONFIG_SMP | |
226 | " sync \n" | |
227 | #endif | |
228 | : "=&r" (retval), "=m" (*m), "=&r" (dummy) | |
229 | : "R" (*m), "Jr" (val) | |
230 | : "memory"); | |
231 | } else if (cpu_has_llsc) { | |
232 | unsigned long dummy; | |
233 | ||
234 | __asm__ __volatile__( | |
235 | "1: lld %0, %3 # xchg_u64 \n" | |
236 | " move %2, %z4 \n" | |
237 | " scd %2, %1 \n" | |
238 | " beqz %2, 1b \n" | |
239 | #ifdef CONFIG_SMP | |
240 | " sync \n" | |
241 | #endif | |
242 | : "=&r" (retval), "=m" (*m), "=&r" (dummy) | |
243 | : "R" (*m), "Jr" (val) | |
244 | : "memory"); | |
245 | } else { | |
246 | unsigned long flags; | |
247 | ||
248 | local_irq_save(flags); | |
249 | retval = *m; | |
250 | *m = val; | |
251 | local_irq_restore(flags); /* implies memory barrier */ | |
252 | } | |
253 | ||
254 | return retval; | |
255 | } | |
256 | #else | |
257 | extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val); | |
258 | #define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels | |
259 | #endif | |
260 | ||
261 | /* This function doesn't exist, so you'll get a linker error | |
262 | if something tries to do an invalid xchg(). */ | |
263 | extern void __xchg_called_with_bad_pointer(void); | |
264 | ||
265 | static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) | |
266 | { | |
267 | switch (size) { | |
268 | case 4: | |
269 | return __xchg_u32(ptr, x); | |
270 | case 8: | |
271 | return __xchg_u64(ptr, x); | |
272 | } | |
273 | __xchg_called_with_bad_pointer(); | |
274 | return x; | |
275 | } | |
276 | ||
277 | #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) | |
278 | #define tas(ptr) (xchg((ptr),1)) | |
279 | ||
280 | #define __HAVE_ARCH_CMPXCHG 1 | |
281 | ||
282 | static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old, | |
283 | unsigned long new) | |
284 | { | |
285 | __u32 retval; | |
286 | ||
287 | if (cpu_has_llsc && R10000_LLSC_WAR) { | |
288 | __asm__ __volatile__( | |
289 | " .set noat \n" | |
290 | "1: ll %0, %2 # __cmpxchg_u32 \n" | |
291 | " bne %0, %z3, 2f \n" | |
292 | " move $1, %z4 \n" | |
293 | " sc $1, %1 \n" | |
294 | " beqzl $1, 1b \n" | |
295 | ROT_IN_PIECES | |
296 | #ifdef CONFIG_SMP | |
297 | " sync \n" | |
298 | #endif | |
299 | "2: \n" | |
300 | " .set at \n" | |
301 | : "=&r" (retval), "=m" (*m) | |
302 | : "R" (*m), "Jr" (old), "Jr" (new) | |
303 | : "memory"); | |
304 | } else if (cpu_has_llsc) { | |
305 | __asm__ __volatile__( | |
306 | " .set noat \n" | |
307 | "1: ll %0, %2 # __cmpxchg_u32 \n" | |
308 | " bne %0, %z3, 2f \n" | |
309 | " move $1, %z4 \n" | |
310 | " sc $1, %1 \n" | |
311 | " beqz $1, 1b \n" | |
312 | #ifdef CONFIG_SMP | |
313 | " sync \n" | |
314 | #endif | |
315 | "2: \n" | |
316 | " .set at \n" | |
317 | : "=&r" (retval), "=m" (*m) | |
318 | : "R" (*m), "Jr" (old), "Jr" (new) | |
319 | : "memory"); | |
320 | } else { | |
321 | unsigned long flags; | |
322 | ||
323 | local_irq_save(flags); | |
324 | retval = *m; | |
325 | if (retval == old) | |
326 | *m = new; | |
327 | local_irq_restore(flags); /* implies memory barrier */ | |
328 | } | |
329 | ||
330 | return retval; | |
331 | } | |
332 | ||
333 | #ifdef CONFIG_MIPS64 | |
334 | static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old, | |
335 | unsigned long new) | |
336 | { | |
337 | __u64 retval; | |
338 | ||
339 | if (cpu_has_llsc) { | |
340 | __asm__ __volatile__( | |
341 | " .set noat \n" | |
342 | "1: lld %0, %2 # __cmpxchg_u64 \n" | |
343 | " bne %0, %z3, 2f \n" | |
344 | " move $1, %z4 \n" | |
345 | " scd $1, %1 \n" | |
346 | " beqzl $1, 1b \n" | |
347 | ROT_IN_PIECES | |
348 | #ifdef CONFIG_SMP | |
349 | " sync \n" | |
350 | #endif | |
351 | "2: \n" | |
352 | " .set at \n" | |
353 | : "=&r" (retval), "=m" (*m) | |
354 | : "R" (*m), "Jr" (old), "Jr" (new) | |
355 | : "memory"); | |
356 | } else if (cpu_has_llsc) { | |
357 | __asm__ __volatile__( | |
358 | " .set noat \n" | |
359 | "1: lld %0, %2 # __cmpxchg_u64 \n" | |
360 | " bne %0, %z3, 2f \n" | |
361 | " move $1, %z4 \n" | |
362 | " scd $1, %1 \n" | |
363 | " beqz $1, 1b \n" | |
364 | #ifdef CONFIG_SMP | |
365 | " sync \n" | |
366 | #endif | |
367 | "2: \n" | |
368 | " .set at \n" | |
369 | : "=&r" (retval), "=m" (*m) | |
370 | : "R" (*m), "Jr" (old), "Jr" (new) | |
371 | : "memory"); | |
372 | } else { | |
373 | unsigned long flags; | |
374 | ||
375 | local_irq_save(flags); | |
376 | retval = *m; | |
377 | if (retval == old) | |
378 | *m = new; | |
379 | local_irq_restore(flags); /* implies memory barrier */ | |
380 | } | |
381 | ||
382 | return retval; | |
383 | } | |
384 | #else | |
385 | extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels( | |
386 | volatile int * m, unsigned long old, unsigned long new); | |
387 | #define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels | |
388 | #endif | |
389 | ||
390 | /* This function doesn't exist, so you'll get a linker error | |
391 | if something tries to do an invalid cmpxchg(). */ | |
392 | extern void __cmpxchg_called_with_bad_pointer(void); | |
393 | ||
394 | static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old, | |
395 | unsigned long new, int size) | |
396 | { | |
397 | switch (size) { | |
398 | case 4: | |
399 | return __cmpxchg_u32(ptr, old, new); | |
400 | case 8: | |
401 | return __cmpxchg_u64(ptr, old, new); | |
402 | } | |
403 | __cmpxchg_called_with_bad_pointer(); | |
404 | return old; | |
405 | } | |
406 | ||
407 | #define cmpxchg(ptr,old,new) ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), (unsigned long)(new),sizeof(*(ptr)))) | |
408 | ||
409 | extern void *set_except_vector(int n, void *addr); | |
410 | extern void per_cpu_trap_init(void); | |
411 | ||
412 | extern NORET_TYPE void __die(const char *, struct pt_regs *, const char *file, | |
413 | const char *func, unsigned long line); | |
414 | extern void __die_if_kernel(const char *, struct pt_regs *, const char *file, | |
415 | const char *func, unsigned long line); | |
416 | ||
417 | #define die(msg, regs) \ | |
418 | __die(msg, regs, __FILE__ ":", __FUNCTION__, __LINE__) | |
419 | #define die_if_kernel(msg, regs) \ | |
420 | __die_if_kernel(msg, regs, __FILE__ ":", __FUNCTION__, __LINE__) | |
421 | ||
422 | extern int stop_a_enabled; | |
423 | ||
424 | /* | |
4866cde0 | 425 | * See include/asm-ia64/system.h; prevents deadlock on SMP |
1da177e4 LT |
426 | * systems. |
427 | */ | |
4866cde0 | 428 | #define __ARCH_WANT_UNLOCKED_CTXSW |
1da177e4 LT |
429 | |
430 | #define arch_align_stack(x) (x) | |
431 | ||
432 | #endif /* _ASM_SYSTEM_H */ |