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