1 #ifndef _ASM_M32R_SYSTEM_H
2 #define _ASM_M32R_SYSTEM_H
3
4 /*
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License. See the file "COPYING" in the main directory of this archive
7 * for more details.
8 *
9 * Copyright (C) 2001 Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto
10 * Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
11 */
12
13 #include <linux/compiler.h>
14 #include <asm/assembler.h>
15
16 #ifdef __KERNEL__
17
18 /*
19 * switch_to(prev, next) should switch from task `prev' to `next'
20 * `prev' will never be the same as `next'.
21 *
22 * `next' and `prev' should be struct task_struct, but it isn't always defined
23 */
24
25 #if defined(CONFIG_FRAME_POINTER) || \
26 !defined(CONFIG_SCHED_OMIT_FRAME_POINTER)
27 #define M32R_PUSH_FP " push fp\n"
28 #define M32R_POP_FP " pop fp\n"
29 #else
30 #define M32R_PUSH_FP ""
31 #define M32R_POP_FP ""
32 #endif
33
34 #define switch_to(prev, next, last) do { \
35 __asm__ __volatile__ ( \
36 " seth lr, #high(1f) \n" \
37 " or3 lr, lr, #low(1f) \n" \
38 " st lr, @%4 ; store old LR \n" \
39 " ld lr, @%5 ; load new LR \n" \
40 M32R_PUSH_FP \
41 " st sp, @%2 ; store old SP \n" \
42 " ld sp, @%3 ; load new SP \n" \
43 " push %1 ; store `prev' on new stack \n" \
44 " jmp lr \n" \
45 " .fillinsn \n" \
46 "1: \n" \
47 " pop %0 ; restore `__last' from new stack \n" \
48 M32R_POP_FP \
49 : "=r" (last) \
50 : "0" (prev), \
51 "r" (&(prev->thread.sp)), "r" (&(next->thread.sp)), \
52 "r" (&(prev->thread.lr)), "r" (&(next->thread.lr)) \
53 : "memory", "lr" \
54 ); \
55 } while(0)
56
57 /* Interrupt Control */
58 #if !defined(CONFIG_CHIP_M32102) && !defined(CONFIG_CHIP_M32104)
59 #define local_irq_enable() \
60 __asm__ __volatile__ ("setpsw #0x40 -> nop": : :"memory")
61 #define local_irq_disable() \
62 __asm__ __volatile__ ("clrpsw #0x40 -> nop": : :"memory")
63 #else /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
local_irq_enable(void)64 static inline void local_irq_enable(void)
65 {
66 unsigned long tmpreg;
67 __asm__ __volatile__(
68 "mvfc %0, psw; \n\t"
69 "or3 %0, %0, #0x0040; \n\t"
70 "mvtc %0, psw; \n\t"
71 : "=&r" (tmpreg) : : "cbit", "memory");
72 }
73
local_irq_disable(void)74 static inline void local_irq_disable(void)
75 {
76 unsigned long tmpreg0, tmpreg1;
77 __asm__ __volatile__(
78 "ld24 %0, #0 ; Use 32-bit insn. \n\t"
79 "mvfc %1, psw ; No interrupt can be accepted here. \n\t"
80 "mvtc %0, psw \n\t"
81 "and3 %0, %1, #0xffbf \n\t"
82 "mvtc %0, psw \n\t"
83 : "=&r" (tmpreg0), "=&r" (tmpreg1) : : "cbit", "memory");
84 }
85 #endif /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
86
87 #define local_save_flags(x) \
88 __asm__ __volatile__("mvfc %0,psw" : "=r"(x) : /* no input */)
89
90 #define local_irq_restore(x) \
91 __asm__ __volatile__("mvtc %0,psw" : /* no outputs */ \
92 : "r" (x) : "cbit", "memory")
93
94 #if !(defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_M32104))
95 #define local_irq_save(x) \
96 __asm__ __volatile__( \
97 "mvfc %0, psw; \n\t" \
98 "clrpsw #0x40 -> nop; \n\t" \
99 : "=r" (x) : /* no input */ : "memory")
100 #else /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
101 #define local_irq_save(x) \
102 ({ \
103 unsigned long tmpreg; \
104 __asm__ __volatile__( \
105 "ld24 %1, #0 \n\t" \
106 "mvfc %0, psw \n\t" \
107 "mvtc %1, psw \n\t" \
108 "and3 %1, %0, #0xffbf \n\t" \
109 "mvtc %1, psw \n\t" \
110 : "=r" (x), "=&r" (tmpreg) \
111 : : "cbit", "memory"); \
112 })
113 #endif /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
114
115 #define irqs_disabled() \
116 ({ \
117 unsigned long flags; \
118 local_save_flags(flags); \
119 !(flags & 0x40); \
120 })
121
122 #define nop() __asm__ __volatile__ ("nop" : : )
123
124 #define xchg(ptr, x) \
125 ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
126 #define xchg_local(ptr, x) \
127 ((__typeof__(*(ptr)))__xchg_local((unsigned long)(x), (ptr), \
128 sizeof(*(ptr))))
129
130 extern void __xchg_called_with_bad_pointer(void);
131
132 #ifdef CONFIG_CHIP_M32700_TS1
133 #define DCACHE_CLEAR(reg0, reg1, addr) \
134 "seth "reg1", #high(dcache_dummy); \n\t" \
135 "or3 "reg1", "reg1", #low(dcache_dummy); \n\t" \
136 "lock "reg0", @"reg1"; \n\t" \
137 "add3 "reg0", "addr", #0x1000; \n\t" \
138 "ld "reg0", @"reg0"; \n\t" \
139 "add3 "reg0", "addr", #0x2000; \n\t" \
140 "ld "reg0", @"reg0"; \n\t" \
141 "unlock "reg0", @"reg1"; \n\t"
142 /* FIXME: This workaround code cannot handle kernel modules
143 * correctly under SMP environment.
144 */
145 #else /* CONFIG_CHIP_M32700_TS1 */
146 #define DCACHE_CLEAR(reg0, reg1, addr)
147 #endif /* CONFIG_CHIP_M32700_TS1 */
148
149 static __always_inline unsigned long
__xchg(unsigned long x,volatile void * ptr,int size)150 __xchg(unsigned long x, volatile void *ptr, int size)
151 {
152 unsigned long flags;
153 unsigned long tmp = 0;
154
155 local_irq_save(flags);
156
157 switch (size) {
158 #ifndef CONFIG_SMP
159 case 1:
160 __asm__ __volatile__ (
161 "ldb %0, @%2 \n\t"
162 "stb %1, @%2 \n\t"
163 : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
164 break;
165 case 2:
166 __asm__ __volatile__ (
167 "ldh %0, @%2 \n\t"
168 "sth %1, @%2 \n\t"
169 : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
170 break;
171 case 4:
172 __asm__ __volatile__ (
173 "ld %0, @%2 \n\t"
174 "st %1, @%2 \n\t"
175 : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
176 break;
177 #else /* CONFIG_SMP */
178 case 4:
179 __asm__ __volatile__ (
180 DCACHE_CLEAR("%0", "r4", "%2")
181 "lock %0, @%2; \n\t"
182 "unlock %1, @%2; \n\t"
183 : "=&r" (tmp) : "r" (x), "r" (ptr)
184 : "memory"
185 #ifdef CONFIG_CHIP_M32700_TS1
186 , "r4"
187 #endif /* CONFIG_CHIP_M32700_TS1 */
188 );
189 break;
190 #endif /* CONFIG_SMP */
191 default:
192 __xchg_called_with_bad_pointer();
193 }
194
195 local_irq_restore(flags);
196
197 return (tmp);
198 }
199
200 static __always_inline unsigned long
__xchg_local(unsigned long x,volatile void * ptr,int size)201 __xchg_local(unsigned long x, volatile void *ptr, int size)
202 {
203 unsigned long flags;
204 unsigned long tmp = 0;
205
206 local_irq_save(flags);
207
208 switch (size) {
209 case 1:
210 __asm__ __volatile__ (
211 "ldb %0, @%2 \n\t"
212 "stb %1, @%2 \n\t"
213 : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
214 break;
215 case 2:
216 __asm__ __volatile__ (
217 "ldh %0, @%2 \n\t"
218 "sth %1, @%2 \n\t"
219 : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
220 break;
221 case 4:
222 __asm__ __volatile__ (
223 "ld %0, @%2 \n\t"
224 "st %1, @%2 \n\t"
225 : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
226 break;
227 default:
228 __xchg_called_with_bad_pointer();
229 }
230
231 local_irq_restore(flags);
232
233 return (tmp);
234 }
235
236 #define __HAVE_ARCH_CMPXCHG 1
237
238 static inline unsigned long
__cmpxchg_u32(volatile unsigned int * p,unsigned int old,unsigned int new)239 __cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new)
240 {
241 unsigned long flags;
242 unsigned int retval;
243
244 local_irq_save(flags);
245 __asm__ __volatile__ (
246 DCACHE_CLEAR("%0", "r4", "%1")
247 M32R_LOCK" %0, @%1; \n"
248 " bne %0, %2, 1f; \n"
249 M32R_UNLOCK" %3, @%1; \n"
250 " bra 2f; \n"
251 " .fillinsn \n"
252 "1:"
253 M32R_UNLOCK" %0, @%1; \n"
254 " .fillinsn \n"
255 "2:"
256 : "=&r" (retval)
257 : "r" (p), "r" (old), "r" (new)
258 : "cbit", "memory"
259 #ifdef CONFIG_CHIP_M32700_TS1
260 , "r4"
261 #endif /* CONFIG_CHIP_M32700_TS1 */
262 );
263 local_irq_restore(flags);
264
265 return retval;
266 }
267
268 static inline unsigned long
__cmpxchg_local_u32(volatile unsigned int * p,unsigned int old,unsigned int new)269 __cmpxchg_local_u32(volatile unsigned int *p, unsigned int old,
270 unsigned int new)
271 {
272 unsigned long flags;
273 unsigned int retval;
274
275 local_irq_save(flags);
276 __asm__ __volatile__ (
277 DCACHE_CLEAR("%0", "r4", "%1")
278 "ld %0, @%1; \n"
279 " bne %0, %2, 1f; \n"
280 "st %3, @%1; \n"
281 " bra 2f; \n"
282 " .fillinsn \n"
283 "1:"
284 "st %0, @%1; \n"
285 " .fillinsn \n"
286 "2:"
287 : "=&r" (retval)
288 : "r" (p), "r" (old), "r" (new)
289 : "cbit", "memory"
290 #ifdef CONFIG_CHIP_M32700_TS1
291 , "r4"
292 #endif /* CONFIG_CHIP_M32700_TS1 */
293 );
294 local_irq_restore(flags);
295
296 return retval;
297 }
298
299 /* This function doesn't exist, so you'll get a linker error
300 if something tries to do an invalid cmpxchg(). */
301 extern void __cmpxchg_called_with_bad_pointer(void);
302
303 static inline unsigned long
__cmpxchg(volatile void * ptr,unsigned long old,unsigned long new,int size)304 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
305 {
306 switch (size) {
307 case 4:
308 return __cmpxchg_u32(ptr, old, new);
309 #if 0 /* we don't have __cmpxchg_u64 */
310 case 8:
311 return __cmpxchg_u64(ptr, old, new);
312 #endif /* 0 */
313 }
314 __cmpxchg_called_with_bad_pointer();
315 return old;
316 }
317
318 #define cmpxchg(ptr, o, n) \
319 ((__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)(o), \
320 (unsigned long)(n), sizeof(*(ptr))))
321
322 #include <asm-generic/cmpxchg-local.h>
323
__cmpxchg_local(volatile void * ptr,unsigned long old,unsigned long new,int size)324 static inline unsigned long __cmpxchg_local(volatile void *ptr,
325 unsigned long old,
326 unsigned long new, int size)
327 {
328 switch (size) {
329 case 4:
330 return __cmpxchg_local_u32(ptr, old, new);
331 default:
332 return __cmpxchg_local_generic(ptr, old, new, size);
333 }
334
335 return old;
336 }
337
338 /*
339 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
340 * them available.
341 */
342 #define cmpxchg_local(ptr, o, n) \
343 ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
344 (unsigned long)(n), sizeof(*(ptr))))
345 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
346
347 #endif /* __KERNEL__ */
348
349 /*
350 * Memory barrier.
351 *
352 * mb() prevents loads and stores being reordered across this point.
353 * rmb() prevents loads being reordered across this point.
354 * wmb() prevents stores being reordered across this point.
355 */
356 #define mb() barrier()
357 #define rmb() mb()
358 #define wmb() mb()
359
360 /**
361 * read_barrier_depends - Flush all pending reads that subsequents reads
362 * depend on.
363 *
364 * No data-dependent reads from memory-like regions are ever reordered
365 * over this barrier. All reads preceding this primitive are guaranteed
366 * to access memory (but not necessarily other CPUs' caches) before any
367 * reads following this primitive that depend on the data return by
368 * any of the preceding reads. This primitive is much lighter weight than
369 * rmb() on most CPUs, and is never heavier weight than is
370 * rmb().
371 *
372 * These ordering constraints are respected by both the local CPU
373 * and the compiler.
374 *
375 * Ordering is not guaranteed by anything other than these primitives,
376 * not even by data dependencies. See the documentation for
377 * memory_barrier() for examples and URLs to more information.
378 *
379 * For example, the following code would force ordering (the initial
380 * value of "a" is zero, "b" is one, and "p" is "&a"):
381 *
382 * <programlisting>
383 * CPU 0 CPU 1
384 *
385 * b = 2;
386 * memory_barrier();
387 * p = &b; q = p;
388 * read_barrier_depends();
389 * d = *q;
390 * </programlisting>
391 *
392 *
393 * because the read of "*q" depends on the read of "p" and these
394 * two reads are separated by a read_barrier_depends(). However,
395 * the following code, with the same initial values for "a" and "b":
396 *
397 * <programlisting>
398 * CPU 0 CPU 1
399 *
400 * a = 2;
401 * memory_barrier();
402 * b = 3; y = b;
403 * read_barrier_depends();
404 * x = a;
405 * </programlisting>
406 *
407 * does not enforce ordering, since there is no data dependency between
408 * the read of "a" and the read of "b". Therefore, on some CPUs, such
409 * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb()
410 * in cases like this where there are no data dependencies.
411 **/
412
413 #define read_barrier_depends() do { } while (0)
414
415 #ifdef CONFIG_SMP
416 #define smp_mb() mb()
417 #define smp_rmb() rmb()
418 #define smp_wmb() wmb()
419 #define smp_read_barrier_depends() read_barrier_depends()
420 #define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
421 #else
422 #define smp_mb() barrier()
423 #define smp_rmb() barrier()
424 #define smp_wmb() barrier()
425 #define smp_read_barrier_depends() do { } while (0)
426 #define set_mb(var, value) do { var = value; barrier(); } while (0)
427 #endif
428
429 #define arch_align_stack(x) (x)
430
431 #endif /* _ASM_M32R_SYSTEM_H */
432