sparc64: Fix global reg snapshotting on self-cpu.
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / include / asm-sparc64 / spinlock.h
blob0006fe9f8c7a03cab556cec5119ad5c016608e74
1 /* spinlock.h: 64-bit Sparc spinlock support.
3 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
4 */
6 #ifndef __SPARC64_SPINLOCK_H
7 #define __SPARC64_SPINLOCK_H
9 #include <linux/threads.h> /* For NR_CPUS */
11 #ifndef __ASSEMBLY__
13 /* To get debugging spinlocks which detect and catch
14 * deadlock situations, set CONFIG_DEBUG_SPINLOCK
15 * and rebuild your kernel.
18 /* All of these locking primitives are expected to work properly
19 * even in an RMO memory model, which currently is what the kernel
20 * runs in.
22 * There is another issue. Because we play games to save cycles
23 * in the non-contention case, we need to be extra careful about
24 * branch targets into the "spinning" code. They live in their
25 * own section, but the newer V9 branches have a shorter range
26 * than the traditional 32-bit sparc branch variants. The rule
27 * is that the branches that go into and out of the spinner sections
28 * must be pre-V9 branches.
31 #define __raw_spin_is_locked(lp) ((lp)->lock != 0)
33 #define __raw_spin_unlock_wait(lp) \
34 do { rmb(); \
35 } while((lp)->lock)
37 static inline void __raw_spin_lock(raw_spinlock_t *lock)
39 unsigned long tmp;
41 __asm__ __volatile__(
42 "1: ldstub [%1], %0\n"
43 " membar #StoreLoad | #StoreStore\n"
44 " brnz,pn %0, 2f\n"
45 " nop\n"
46 " .subsection 2\n"
47 "2: ldub [%1], %0\n"
48 " membar #LoadLoad\n"
49 " brnz,pt %0, 2b\n"
50 " nop\n"
51 " ba,a,pt %%xcc, 1b\n"
52 " .previous"
53 : "=&r" (tmp)
54 : "r" (lock)
55 : "memory");
58 static inline int __raw_spin_trylock(raw_spinlock_t *lock)
60 unsigned long result;
62 __asm__ __volatile__(
63 " ldstub [%1], %0\n"
64 " membar #StoreLoad | #StoreStore"
65 : "=r" (result)
66 : "r" (lock)
67 : "memory");
69 return (result == 0UL);
72 static inline void __raw_spin_unlock(raw_spinlock_t *lock)
74 __asm__ __volatile__(
75 " membar #StoreStore | #LoadStore\n"
76 " stb %%g0, [%0]"
77 : /* No outputs */
78 : "r" (lock)
79 : "memory");
82 static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
84 unsigned long tmp1, tmp2;
86 __asm__ __volatile__(
87 "1: ldstub [%2], %0\n"
88 " membar #StoreLoad | #StoreStore\n"
89 " brnz,pn %0, 2f\n"
90 " nop\n"
91 " .subsection 2\n"
92 "2: rdpr %%pil, %1\n"
93 " wrpr %3, %%pil\n"
94 "3: ldub [%2], %0\n"
95 " membar #LoadLoad\n"
96 " brnz,pt %0, 3b\n"
97 " nop\n"
98 " ba,pt %%xcc, 1b\n"
99 " wrpr %1, %%pil\n"
100 " .previous"
101 : "=&r" (tmp1), "=&r" (tmp2)
102 : "r"(lock), "r"(flags)
103 : "memory");
106 /* Multi-reader locks, these are much saner than the 32-bit Sparc ones... */
108 static void inline __read_lock(raw_rwlock_t *lock)
110 unsigned long tmp1, tmp2;
112 __asm__ __volatile__ (
113 "1: ldsw [%2], %0\n"
114 " brlz,pn %0, 2f\n"
115 "4: add %0, 1, %1\n"
116 " cas [%2], %0, %1\n"
117 " cmp %0, %1\n"
118 " membar #StoreLoad | #StoreStore\n"
119 " bne,pn %%icc, 1b\n"
120 " nop\n"
121 " .subsection 2\n"
122 "2: ldsw [%2], %0\n"
123 " membar #LoadLoad\n"
124 " brlz,pt %0, 2b\n"
125 " nop\n"
126 " ba,a,pt %%xcc, 4b\n"
127 " .previous"
128 : "=&r" (tmp1), "=&r" (tmp2)
129 : "r" (lock)
130 : "memory");
133 static int inline __read_trylock(raw_rwlock_t *lock)
135 int tmp1, tmp2;
137 __asm__ __volatile__ (
138 "1: ldsw [%2], %0\n"
139 " brlz,a,pn %0, 2f\n"
140 " mov 0, %0\n"
141 " add %0, 1, %1\n"
142 " cas [%2], %0, %1\n"
143 " cmp %0, %1\n"
144 " membar #StoreLoad | #StoreStore\n"
145 " bne,pn %%icc, 1b\n"
146 " mov 1, %0\n"
147 "2:"
148 : "=&r" (tmp1), "=&r" (tmp2)
149 : "r" (lock)
150 : "memory");
152 return tmp1;
155 static void inline __read_unlock(raw_rwlock_t *lock)
157 unsigned long tmp1, tmp2;
159 __asm__ __volatile__(
160 " membar #StoreLoad | #LoadLoad\n"
161 "1: lduw [%2], %0\n"
162 " sub %0, 1, %1\n"
163 " cas [%2], %0, %1\n"
164 " cmp %0, %1\n"
165 " bne,pn %%xcc, 1b\n"
166 " nop"
167 : "=&r" (tmp1), "=&r" (tmp2)
168 : "r" (lock)
169 : "memory");
172 static void inline __write_lock(raw_rwlock_t *lock)
174 unsigned long mask, tmp1, tmp2;
176 mask = 0x80000000UL;
178 __asm__ __volatile__(
179 "1: lduw [%2], %0\n"
180 " brnz,pn %0, 2f\n"
181 "4: or %0, %3, %1\n"
182 " cas [%2], %0, %1\n"
183 " cmp %0, %1\n"
184 " membar #StoreLoad | #StoreStore\n"
185 " bne,pn %%icc, 1b\n"
186 " nop\n"
187 " .subsection 2\n"
188 "2: lduw [%2], %0\n"
189 " membar #LoadLoad\n"
190 " brnz,pt %0, 2b\n"
191 " nop\n"
192 " ba,a,pt %%xcc, 4b\n"
193 " .previous"
194 : "=&r" (tmp1), "=&r" (tmp2)
195 : "r" (lock), "r" (mask)
196 : "memory");
199 static void inline __write_unlock(raw_rwlock_t *lock)
201 __asm__ __volatile__(
202 " membar #LoadStore | #StoreStore\n"
203 " stw %%g0, [%0]"
204 : /* no outputs */
205 : "r" (lock)
206 : "memory");
209 static int inline __write_trylock(raw_rwlock_t *lock)
211 unsigned long mask, tmp1, tmp2, result;
213 mask = 0x80000000UL;
215 __asm__ __volatile__(
216 " mov 0, %2\n"
217 "1: lduw [%3], %0\n"
218 " brnz,pn %0, 2f\n"
219 " or %0, %4, %1\n"
220 " cas [%3], %0, %1\n"
221 " cmp %0, %1\n"
222 " membar #StoreLoad | #StoreStore\n"
223 " bne,pn %%icc, 1b\n"
224 " nop\n"
225 " mov 1, %2\n"
226 "2:"
227 : "=&r" (tmp1), "=&r" (tmp2), "=&r" (result)
228 : "r" (lock), "r" (mask)
229 : "memory");
231 return result;
234 #define __raw_read_lock(p) __read_lock(p)
235 #define __raw_read_trylock(p) __read_trylock(p)
236 #define __raw_read_unlock(p) __read_unlock(p)
237 #define __raw_write_lock(p) __write_lock(p)
238 #define __raw_write_unlock(p) __write_unlock(p)
239 #define __raw_write_trylock(p) __write_trylock(p)
241 #define __raw_read_can_lock(rw) (!((rw)->lock & 0x80000000UL))
242 #define __raw_write_can_lock(rw) (!(rw)->lock)
244 #define _raw_spin_relax(lock) cpu_relax()
245 #define _raw_read_relax(lock) cpu_relax()
246 #define _raw_write_relax(lock) cpu_relax()
248 #endif /* !(__ASSEMBLY__) */
250 #endif /* !(__SPARC64_SPINLOCK_H) */