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Nobuhiro Iwamatsu970dc332007-05-13 20:58:00 +09001#ifndef __ASM_SH_SYSTEM_H
2#define __ASM_SH_SYSTEM_H
3
4/*
5 * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
6 * Copyright (C) 2002 Paul Mundt
7 *
8 * from linux kernel code.
9 */
10
11#include <linux/irqflags.h>
12#include <asm/types.h>
13
14/*
15 * switch_to() should switch tasks to task nr n, first
16 */
17
18#define switch_to(prev, next, last) do { \
19 struct task_struct *__last; \
20 register unsigned long *__ts1 __asm__ ("r1") = &prev->thread.sp; \
21 register unsigned long *__ts2 __asm__ ("r2") = &prev->thread.pc; \
22 register unsigned long *__ts4 __asm__ ("r4") = (unsigned long *)prev; \
23 register unsigned long *__ts5 __asm__ ("r5") = (unsigned long *)next; \
24 register unsigned long *__ts6 __asm__ ("r6") = &next->thread.sp; \
25 register unsigned long __ts7 __asm__ ("r7") = next->thread.pc; \
Wolfgang Denka1be4762008-05-20 16:00:29 +020026 __asm__ __volatile__ (".balign 4\n\t" \
27 "stc.l gbr, @-r15\n\t" \
28 "sts.l pr, @-r15\n\t" \
29 "mov.l r8, @-r15\n\t" \
30 "mov.l r9, @-r15\n\t" \
31 "mov.l r10, @-r15\n\t" \
32 "mov.l r11, @-r15\n\t" \
33 "mov.l r12, @-r15\n\t" \
34 "mov.l r13, @-r15\n\t" \
35 "mov.l r14, @-r15\n\t" \
Nobuhiro Iwamatsu970dc332007-05-13 20:58:00 +090036 "mov.l r15, @r1 ! save SP\n\t" \
37 "mov.l @r6, r15 ! change to new stack\n\t" \
Wolfgang Denka1be4762008-05-20 16:00:29 +020038 "mova 1f, %0\n\t" \
39 "mov.l %0, @r2 ! save PC\n\t" \
40 "mov.l 2f, %0\n\t" \
Nobuhiro Iwamatsu970dc332007-05-13 20:58:00 +090041 "jmp @%0 ! call __switch_to\n\t" \
42 " lds r7, pr ! with return to new PC\n\t" \
43 ".balign 4\n" \
44 "2:\n\t" \
45 ".long __switch_to\n" \
46 "1:\n\t" \
47 "mov.l @r15+, r14\n\t" \
48 "mov.l @r15+, r13\n\t" \
49 "mov.l @r15+, r12\n\t" \
50 "mov.l @r15+, r11\n\t" \
51 "mov.l @r15+, r10\n\t" \
52 "mov.l @r15+, r9\n\t" \
53 "mov.l @r15+, r8\n\t" \
54 "lds.l @r15+, pr\n\t" \
55 "ldc.l @r15+, gbr\n\t" \
56 : "=z" (__last) \
Wolfgang Denka1be4762008-05-20 16:00:29 +020057 : "r" (__ts1), "r" (__ts2), "r" (__ts4), \
58 "r" (__ts5), "r" (__ts6), "r" (__ts7) \
Nobuhiro Iwamatsu970dc332007-05-13 20:58:00 +090059 : "r3", "t"); \
60 last = __last; \
61} while (0)
62
63/*
64 * On SMP systems, when the scheduler does migration-cost autodetection,
65 * it needs a way to flush as much of the CPU's caches as possible.
66 *
67 * TODO: fill this in!
68 */
69static inline void sched_cacheflush(void)
70{
71}
72
73#ifdef CONFIG_CPU_SH4A
74#define __icbi() \
75{ \
76 unsigned long __addr; \
77 __addr = 0xa8000000; \
78 __asm__ __volatile__( \
79 "icbi %0\n\t" \
80 : /* no output */ \
81 : "m" (__m(__addr))); \
82}
83#endif
84
85static inline unsigned long tas(volatile int *m)
86{
87 unsigned long retval;
88
89 __asm__ __volatile__ ("tas.b @%1\n\t"
90 "movt %0"
91 : "=r" (retval): "r" (m): "t", "memory");
92 return retval;
93}
94
95/*
96 * A brief note on ctrl_barrier(), the control register write barrier.
97 *
98 * Legacy SH cores typically require a sequence of 8 nops after
99 * modification of a control register in order for the changes to take
100 * effect. On newer cores (like the sh4a and sh5) this is accomplished
101 * with icbi.
102 *
103 * Also note that on sh4a in the icbi case we can forego a synco for the
104 * write barrier, as it's not necessary for control registers.
105 *
106 * Historically we have only done this type of barrier for the MMUCR, but
107 * it's also necessary for the CCR, so we make it generic here instead.
108 */
109#ifdef CONFIG_CPU_SH4A
110#define mb() __asm__ __volatile__ ("synco": : :"memory")
111#define rmb() mb()
112#define wmb() __asm__ __volatile__ ("synco": : :"memory")
113#define ctrl_barrier() __icbi()
114#define read_barrier_depends() do { } while(0)
115#else
116#define mb() __asm__ __volatile__ ("": : :"memory")
117#define rmb() mb()
118#define wmb() __asm__ __volatile__ ("": : :"memory")
119#define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop")
120#define read_barrier_depends() do { } while(0)
121#endif
122
123#ifdef CONFIG_SMP
124#define smp_mb() mb()
125#define smp_rmb() rmb()
126#define smp_wmb() wmb()
127#define smp_read_barrier_depends() read_barrier_depends()
128#else
129#define smp_mb() barrier()
130#define smp_rmb() barrier()
131#define smp_wmb() barrier()
132#define smp_read_barrier_depends() do { } while(0)
133#endif
134
135#define set_mb(var, value) do { xchg(&var, value); } while (0)
136
137/*
138 * Jump to P2 area.
139 * When handling TLB or caches, we need to do it from P2 area.
140 */
141#define jump_to_P2() \
142do { \
143 unsigned long __dummy; \
144 __asm__ __volatile__( \
145 "mov.l 1f, %0\n\t" \
146 "or %1, %0\n\t" \
147 "jmp @%0\n\t" \
Wolfgang Denka1be4762008-05-20 16:00:29 +0200148 " nop\n\t" \
Nobuhiro Iwamatsu970dc332007-05-13 20:58:00 +0900149 ".balign 4\n" \
150 "1: .long 2f\n" \
151 "2:" \
152 : "=&r" (__dummy) \
153 : "r" (0x20000000)); \
154} while (0)
155
156/*
157 * Back to P1 area.
158 */
159#define back_to_P1() \
160do { \
161 unsigned long __dummy; \
162 ctrl_barrier(); \
163 __asm__ __volatile__( \
164 "mov.l 1f, %0\n\t" \
165 "jmp @%0\n\t" \
166 " nop\n\t" \
167 ".balign 4\n" \
168 "1: .long 2f\n" \
169 "2:" \
170 : "=&r" (__dummy)); \
171} while (0)
172
173static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
174{
175 unsigned long flags, retval;
176
177 local_irq_save(flags);
178 retval = *m;
179 *m = val;
180 local_irq_restore(flags);
181 return retval;
182}
183
184static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
185{
186 unsigned long flags, retval;
187
188 local_irq_save(flags);
189 retval = *m;
190 *m = val & 0xff;
191 local_irq_restore(flags);
192 return retval;
193}
194
195extern void __xchg_called_with_bad_pointer(void);
196
197#define __xchg(ptr, x, size) \
198({ \
199 unsigned long __xchg__res; \
200 volatile void *__xchg_ptr = (ptr); \
201 switch (size) { \
202 case 4: \
203 __xchg__res = xchg_u32(__xchg_ptr, x); \
204 break; \
205 case 1: \
206 __xchg__res = xchg_u8(__xchg_ptr, x); \
207 break; \
208 default: \
209 __xchg_called_with_bad_pointer(); \
210 __xchg__res = x; \
211 break; \
212 } \
213 \
214 __xchg__res; \
215})
216
217#define xchg(ptr,x) \
218 ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
219
220static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
221 unsigned long new)
222{
223 __u32 retval;
224 unsigned long flags;
225
226 local_irq_save(flags);
227 retval = *m;
228 if (retval == old)
229 *m = new;
230 local_irq_restore(flags); /* implies memory barrier */
231 return retval;
232}
233
234/* This function doesn't exist, so you'll get a linker error
235 * if something tries to do an invalid cmpxchg(). */
236extern void __cmpxchg_called_with_bad_pointer(void);
237
238#define __HAVE_ARCH_CMPXCHG 1
239
240static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
241 unsigned long new, int size)
242{
243 switch (size) {
244 case 4:
245 return __cmpxchg_u32(ptr, old, new);
246 }
247 __cmpxchg_called_with_bad_pointer();
248 return old;
249}
250
251#define cmpxchg(ptr,o,n) \
252 ({ \
253 __typeof__(*(ptr)) _o_ = (o); \
254 __typeof__(*(ptr)) _n_ = (n); \
255 (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
256 (unsigned long)_n_, sizeof(*(ptr))); \
257 })
258
259extern void *set_exception_table_vec(unsigned int vec, void *handler);
260
261static inline void *set_exception_table_evt(unsigned int evt, void *handler)
262{
263 return set_exception_table_vec(evt >> 5, handler);
264}
265
266/* XXX
267 * disable hlt during certain critical i/o operations
268 */
269#define HAVE_DISABLE_HLT
270void disable_hlt(void);
271void enable_hlt(void);
272
273#define arch_align_stack(x) (x)
274
275#endif