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11#ifndef _XTENSA_CMPXCHG_H
12#define _XTENSA_CMPXCHG_H
13
14#ifndef __ASSEMBLY__
15
16#include <linux/bits.h>
17#include <linux/stringify.h>
18
19
20
21
22
23static inline unsigned long
24__cmpxchg_u32(volatile int *p, int old, int new)
25{
26#if XCHAL_HAVE_EXCLUSIVE
27 unsigned long tmp, result;
28
29 __asm__ __volatile__(
30 "1: l32ex %[result], %[addr]\n"
31 " bne %[result], %[cmp], 2f\n"
32 " mov %[tmp], %[new]\n"
33 " s32ex %[tmp], %[addr]\n"
34 " getex %[tmp]\n"
35 " beqz %[tmp], 1b\n"
36 "2:\n"
37 : [result] "=&a" (result), [tmp] "=&a" (tmp)
38 : [new] "a" (new), [addr] "a" (p), [cmp] "a" (old)
39 : "memory"
40 );
41
42 return result;
43#elif XCHAL_HAVE_S32C1I
44 __asm__ __volatile__(
45 " wsr %[cmp], scompare1\n"
46 " s32c1i %[new], %[mem]\n"
47 : [new] "+a" (new), [mem] "+m" (*p)
48 : [cmp] "a" (old)
49 : "memory"
50 );
51
52 return new;
53#else
54 __asm__ __volatile__(
55 " rsil a15, "__stringify(TOPLEVEL)"\n"
56 " l32i %[old], %[mem]\n"
57 " bne %[old], %[cmp], 1f\n"
58 " s32i %[new], %[mem]\n"
59 "1:\n"
60 " wsr a15, ps\n"
61 " rsync\n"
62 : [old] "=&a" (old), [mem] "+m" (*p)
63 : [cmp] "a" (old), [new] "r" (new)
64 : "a15", "memory");
65 return old;
66#endif
67}
68
69
70
71extern void __cmpxchg_called_with_bad_pointer(void);
72
73static __inline__ unsigned long
74__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
75{
76 switch (size) {
77 case 4: return __cmpxchg_u32(ptr, old, new);
78 default: __cmpxchg_called_with_bad_pointer();
79 return old;
80 }
81}
82
83#define arch_cmpxchg(ptr,o,n) \
84 ({ __typeof__(*(ptr)) _o_ = (o); \
85 __typeof__(*(ptr)) _n_ = (n); \
86 (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
87 (unsigned long)_n_, sizeof (*(ptr))); \
88 })
89
90#include <asm-generic/cmpxchg-local.h>
91
92static inline unsigned long __cmpxchg_local(volatile void *ptr,
93 unsigned long old,
94 unsigned long new, int size)
95{
96 switch (size) {
97 case 4:
98 return __cmpxchg_u32(ptr, old, new);
99 default:
100 return __generic_cmpxchg_local(ptr, old, new, size);
101 }
102
103 return old;
104}
105
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108
109
110#define arch_cmpxchg_local(ptr, o, n) \
111 ((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),\
112 (unsigned long)(n), sizeof(*(ptr))))
113#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
114#define arch_cmpxchg64(ptr, o, n) arch_cmpxchg64_local((ptr), (o), (n))
115
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124
125
126static inline unsigned long xchg_u32(volatile int * m, unsigned long val)
127{
128#if XCHAL_HAVE_EXCLUSIVE
129 unsigned long tmp, result;
130
131 __asm__ __volatile__(
132 "1: l32ex %[result], %[addr]\n"
133 " mov %[tmp], %[val]\n"
134 " s32ex %[tmp], %[addr]\n"
135 " getex %[tmp]\n"
136 " beqz %[tmp], 1b\n"
137 : [result] "=&a" (result), [tmp] "=&a" (tmp)
138 : [val] "a" (val), [addr] "a" (m)
139 : "memory"
140 );
141
142 return result;
143#elif XCHAL_HAVE_S32C1I
144 unsigned long tmp, result;
145 __asm__ __volatile__(
146 "1: l32i %[tmp], %[mem]\n"
147 " mov %[result], %[val]\n"
148 " wsr %[tmp], scompare1\n"
149 " s32c1i %[result], %[mem]\n"
150 " bne %[result], %[tmp], 1b\n"
151 : [result] "=&a" (result), [tmp] "=&a" (tmp),
152 [mem] "+m" (*m)
153 : [val] "a" (val)
154 : "memory"
155 );
156 return result;
157#else
158 unsigned long tmp;
159 __asm__ __volatile__(
160 " rsil a15, "__stringify(TOPLEVEL)"\n"
161 " l32i %[tmp], %[mem]\n"
162 " s32i %[val], %[mem]\n"
163 " wsr a15, ps\n"
164 " rsync\n"
165 : [tmp] "=&a" (tmp), [mem] "+m" (*m)
166 : [val] "a" (val)
167 : "a15", "memory");
168 return tmp;
169#endif
170}
171
172#define arch_xchg(ptr,x) \
173 ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
174
175static inline u32 xchg_small(volatile void *ptr, u32 x, int size)
176{
177 int off = (unsigned long)ptr % sizeof(u32);
178 volatile u32 *p = ptr - off;
179#ifdef __BIG_ENDIAN
180 int bitoff = (sizeof(u32) - size - off) * BITS_PER_BYTE;
181#else
182 int bitoff = off * BITS_PER_BYTE;
183#endif
184 u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff;
185 u32 oldv, newv;
186 u32 ret;
187
188 do {
189 oldv = READ_ONCE(*p);
190 ret = (oldv & bitmask) >> bitoff;
191 newv = (oldv & ~bitmask) | (x << bitoff);
192 } while (__cmpxchg_u32(p, oldv, newv) != oldv);
193
194 return ret;
195}
196
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201
202
203extern void __xchg_called_with_bad_pointer(void);
204
205static __inline__ unsigned long
206__xchg(unsigned long x, volatile void * ptr, int size)
207{
208 switch (size) {
209 case 1:
210 return xchg_small(ptr, x, 1);
211 case 2:
212 return xchg_small(ptr, x, 2);
213 case 4:
214 return xchg_u32(ptr, x);
215 default:
216 __xchg_called_with_bad_pointer();
217 return x;
218 }
219}
220
221#endif
222
223#endif
224