Merge branch 'paul' (Fixups from Paul Gortmaker)
[~shefty/rdma-dev.git] / arch / blackfin / include / asm / cmpxchg.h
1 /*
2  * Copyright 2004-2011 Analog Devices Inc.
3  *
4  * Licensed under the GPL-2 or later.
5  */
6
7 #ifndef __ARCH_BLACKFIN_CMPXCHG__
8 #define __ARCH_BLACKFIN_CMPXCHG__
9
10 #ifdef CONFIG_SMP
11
12 #include <linux/linkage.h>
13
14 asmlinkage unsigned long __raw_xchg_1_asm(volatile void *ptr, unsigned long value);
15 asmlinkage unsigned long __raw_xchg_2_asm(volatile void *ptr, unsigned long value);
16 asmlinkage unsigned long __raw_xchg_4_asm(volatile void *ptr, unsigned long value);
17 asmlinkage unsigned long __raw_cmpxchg_1_asm(volatile void *ptr,
18                                         unsigned long new, unsigned long old);
19 asmlinkage unsigned long __raw_cmpxchg_2_asm(volatile void *ptr,
20                                         unsigned long new, unsigned long old);
21 asmlinkage unsigned long __raw_cmpxchg_4_asm(volatile void *ptr,
22                                         unsigned long new, unsigned long old);
23
24 static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
25                                    int size)
26 {
27         unsigned long tmp;
28
29         switch (size) {
30         case 1:
31                 tmp = __raw_xchg_1_asm(ptr, x);
32                 break;
33         case 2:
34                 tmp = __raw_xchg_2_asm(ptr, x);
35                 break;
36         case 4:
37                 tmp = __raw_xchg_4_asm(ptr, x);
38                 break;
39         }
40
41         return tmp;
42 }
43
44 /*
45  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
46  * store NEW in MEM.  Return the initial value in MEM.  Success is
47  * indicated by comparing RETURN with OLD.
48  */
49 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
50                                       unsigned long new, int size)
51 {
52         unsigned long tmp;
53
54         switch (size) {
55         case 1:
56                 tmp = __raw_cmpxchg_1_asm(ptr, new, old);
57                 break;
58         case 2:
59                 tmp = __raw_cmpxchg_2_asm(ptr, new, old);
60                 break;
61         case 4:
62                 tmp = __raw_cmpxchg_4_asm(ptr, new, old);
63                 break;
64         }
65
66         return tmp;
67 }
68 #define cmpxchg(ptr, o, n) \
69         ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
70                 (unsigned long)(n), sizeof(*(ptr))))
71
72 #else /* !CONFIG_SMP */
73
74 #include <mach/blackfin.h>
75 #include <asm/irqflags.h>
76
77 struct __xchg_dummy {
78         unsigned long a[100];
79 };
80 #define __xg(x) ((volatile struct __xchg_dummy *)(x))
81
82 static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
83                                    int size)
84 {
85         unsigned long tmp = 0;
86         unsigned long flags;
87
88         flags = hard_local_irq_save();
89
90         switch (size) {
91         case 1:
92                 __asm__ __volatile__
93                         ("%0 = b%2 (z);\n\t"
94                          "b%2 = %1;\n\t"
95                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
96                 break;
97         case 2:
98                 __asm__ __volatile__
99                         ("%0 = w%2 (z);\n\t"
100                          "w%2 = %1;\n\t"
101                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
102                 break;
103         case 4:
104                 __asm__ __volatile__
105                         ("%0 = %2;\n\t"
106                          "%2 = %1;\n\t"
107                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
108                 break;
109         }
110         hard_local_irq_restore(flags);
111         return tmp;
112 }
113
114 #include <asm-generic/cmpxchg-local.h>
115
116 /*
117  * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
118  * them available.
119  */
120 #define cmpxchg_local(ptr, o, n)                                               \
121         ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
122                         (unsigned long)(n), sizeof(*(ptr))))
123 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
124
125 #define cmpxchg(ptr, o, n)      cmpxchg_local((ptr), (o), (n))
126 #define cmpxchg64(ptr, o, n)    cmpxchg64_local((ptr), (o), (n))
127
128 #endif /* !CONFIG_SMP */
129
130 #define xchg(ptr, x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
131 #define tas(ptr) ((void)xchg((ptr), 1))
132
133 #endif /* __ARCH_BLACKFIN_CMPXCHG__ */