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9a8fd558 CZ |
1 | /* |
2 | * include/asm-xtensa/system.h | |
3 | * | |
4 | * This file is subject to the terms and conditions of the GNU General Public | |
5 | * License. See the file "COPYING" in the main directory of this archive | |
6 | * for more details. | |
7 | * | |
8 | * Copyright (C) 2001 - 2005 Tensilica Inc. | |
9 | */ | |
10 | ||
11 | #ifndef _XTENSA_SYSTEM_H | |
12 | #define _XTENSA_SYSTEM_H | |
13 | ||
9a8fd558 CZ |
14 | #include <linux/stringify.h> |
15 | ||
16 | #include <asm/processor.h> | |
17 | ||
18 | /* interrupt control */ | |
19 | ||
20 | #define local_save_flags(x) \ | |
21 | __asm__ __volatile__ ("rsr %0,"__stringify(PS) : "=a" (x)); | |
22 | #define local_irq_restore(x) do { \ | |
23 | __asm__ __volatile__ ("wsr %0, "__stringify(PS)" ; rsync" \ | |
24 | :: "a" (x) : "memory"); } while(0); | |
25 | #define local_irq_save(x) do { \ | |
26 | __asm__ __volatile__ ("rsil %0, "__stringify(LOCKLEVEL) \ | |
27 | : "=a" (x) :: "memory");} while(0); | |
28 | ||
29 | static inline void local_irq_disable(void) | |
30 | { | |
31 | unsigned long flags; | |
32 | __asm__ __volatile__ ("rsil %0, "__stringify(LOCKLEVEL) | |
33 | : "=a" (flags) :: "memory"); | |
34 | } | |
35 | static inline void local_irq_enable(void) | |
36 | { | |
37 | unsigned long flags; | |
38 | __asm__ __volatile__ ("rsil %0, 0" : "=a" (flags) :: "memory"); | |
39 | ||
40 | } | |
41 | ||
42 | static inline int irqs_disabled(void) | |
43 | { | |
44 | unsigned long flags; | |
45 | local_save_flags(flags); | |
46 | return flags & 0xf; | |
47 | } | |
48 | ||
9a8fd558 CZ |
49 | |
50 | #define smp_read_barrier_depends() do { } while(0) | |
51 | #define read_barrier_depends() do { } while(0) | |
52 | ||
53 | #define mb() barrier() | |
54 | #define rmb() mb() | |
55 | #define wmb() mb() | |
56 | ||
57 | #ifdef CONFIG_SMP | |
58 | #error smp_* not defined | |
59 | #else | |
60 | #define smp_mb() barrier() | |
61 | #define smp_rmb() barrier() | |
62 | #define smp_wmb() barrier() | |
63 | #endif | |
64 | ||
65 | #define set_mb(var, value) do { var = value; mb(); } while (0) | |
9a8fd558 CZ |
66 | |
67 | #if !defined (__ASSEMBLY__) | |
68 | ||
69 | /* * switch_to(n) should switch tasks to task nr n, first | |
70 | * checking that n isn't the current task, in which case it does nothing. | |
71 | */ | |
72 | extern void *_switch_to(void *last, void *next); | |
73 | ||
74 | #endif /* __ASSEMBLY__ */ | |
75 | ||
9a8fd558 CZ |
76 | #define switch_to(prev,next,last) \ |
77 | do { \ | |
9a8fd558 CZ |
78 | (last) = _switch_to(prev, next); \ |
79 | } while(0) | |
80 | ||
81 | /* | |
82 | * cmpxchg | |
83 | */ | |
84 | ||
d99cf715 | 85 | static inline unsigned long |
9a8fd558 CZ |
86 | __cmpxchg_u32(volatile int *p, int old, int new) |
87 | { | |
88 | __asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t" | |
89 | "l32i %0, %1, 0 \n\t" | |
90 | "bne %0, %2, 1f \n\t" | |
91 | "s32i %3, %1, 0 \n\t" | |
92 | "1: \n\t" | |
93 | "wsr a15, "__stringify(PS)" \n\t" | |
94 | "rsync \n\t" | |
95 | : "=&a" (old) | |
96 | : "a" (p), "a" (old), "r" (new) | |
97 | : "a15", "memory"); | |
98 | return old; | |
99 | } | |
100 | /* This function doesn't exist, so you'll get a linker error | |
101 | * if something tries to do an invalid cmpxchg(). */ | |
102 | ||
103 | extern void __cmpxchg_called_with_bad_pointer(void); | |
104 | ||
105 | static __inline__ unsigned long | |
106 | __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) | |
107 | { | |
108 | switch (size) { | |
109 | case 4: return __cmpxchg_u32(ptr, old, new); | |
110 | default: __cmpxchg_called_with_bad_pointer(); | |
111 | return old; | |
112 | } | |
113 | } | |
114 | ||
115 | #define cmpxchg(ptr,o,n) \ | |
116 | ({ __typeof__(*(ptr)) _o_ = (o); \ | |
117 | __typeof__(*(ptr)) _n_ = (n); \ | |
118 | (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ | |
119 | (unsigned long)_n_, sizeof (*(ptr))); \ | |
120 | }) | |
121 | ||
9a7744f9 | 122 | #include <asm-generic/cmpxchg-local.h> |
9a8fd558 | 123 | |
9a7744f9 MD |
124 | static inline unsigned long __cmpxchg_local(volatile void *ptr, |
125 | unsigned long old, | |
126 | unsigned long new, int size) | |
127 | { | |
128 | switch (size) { | |
129 | case 4: | |
130 | return __cmpxchg_u32(ptr, old, new); | |
131 | default: | |
132 | return __cmpxchg_local_generic(ptr, old, new, size); | |
133 | } | |
9a8fd558 | 134 | |
9a7744f9 MD |
135 | return old; |
136 | } | |
137 | ||
138 | /* | |
139 | * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make | |
140 | * them available. | |
141 | */ | |
142 | #define cmpxchg_local(ptr, o, n) \ | |
143 | ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ | |
144 | (unsigned long)(n), sizeof(*(ptr)))) | |
145 | #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) | |
9a8fd558 CZ |
146 | |
147 | /* | |
148 | * xchg_u32 | |
149 | * | |
150 | * Note that a15 is used here because the register allocation | |
151 | * done by the compiler is not guaranteed and a window overflow | |
152 | * may not occur between the rsil and wsr instructions. By using | |
153 | * a15 in the rsil, the machine is guaranteed to be in a state | |
154 | * where no register reference will cause an overflow. | |
155 | */ | |
156 | ||
d99cf715 | 157 | static inline unsigned long xchg_u32(volatile int * m, unsigned long val) |
9a8fd558 CZ |
158 | { |
159 | unsigned long tmp; | |
160 | __asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t" | |
161 | "l32i %0, %1, 0 \n\t" | |
162 | "s32i %2, %1, 0 \n\t" | |
163 | "wsr a15, "__stringify(PS)" \n\t" | |
164 | "rsync \n\t" | |
165 | : "=&a" (tmp) | |
166 | : "a" (m), "a" (val) | |
167 | : "a15", "memory"); | |
168 | return tmp; | |
169 | } | |
170 | ||
9a8fd558 CZ |
171 | #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) |
172 | ||
173 | /* | |
174 | * This only works if the compiler isn't horribly bad at optimizing. | |
175 | * gcc-2.5.8 reportedly can't handle this, but I define that one to | |
176 | * be dead anyway. | |
177 | */ | |
178 | ||
179 | extern void __xchg_called_with_bad_pointer(void); | |
180 | ||
181 | static __inline__ unsigned long | |
182 | __xchg(unsigned long x, volatile void * ptr, int size) | |
183 | { | |
184 | switch (size) { | |
185 | case 4: | |
186 | return xchg_u32(ptr, x); | |
187 | } | |
188 | __xchg_called_with_bad_pointer(); | |
189 | return x; | |
190 | } | |
191 | ||
9a8fd558 CZ |
192 | extern void set_except_vector(int n, void *addr); |
193 | ||
194 | static inline void spill_registers(void) | |
195 | { | |
196 | unsigned int a0, ps; | |
197 | ||
198 | __asm__ __volatile__ ( | |
173d6681 | 199 | "movi a14," __stringify (PS_EXCM_BIT) " | 1\n\t" |
9a8fd558 CZ |
200 | "mov a12, a0\n\t" |
201 | "rsr a13," __stringify(SAR) "\n\t" | |
202 | "xsr a14," __stringify(PS) "\n\t" | |
203 | "movi a0, _spill_registers\n\t" | |
204 | "rsync\n\t" | |
205 | "callx0 a0\n\t" | |
206 | "mov a0, a12\n\t" | |
207 | "wsr a13," __stringify(SAR) "\n\t" | |
208 | "wsr a14," __stringify(PS) "\n\t" | |
209 | :: "a" (&a0), "a" (&ps) | |
c658eac6 | 210 | : "a2", "a3", "a4", "a7", "a11", "a12", "a13", "a14", "a15", "memory"); |
9a8fd558 CZ |
211 | } |
212 | ||
213 | #define arch_align_stack(x) (x) | |
214 | ||
215 | #endif /* _XTENSA_SYSTEM_H */ |