Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* spinlock.h: 64-bit Sparc spinlock support. |
| 2 | * |
| 3 | * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) |
| 4 | */ |
| 5 | |
| 6 | #ifndef __SPARC64_SPINLOCK_H |
| 7 | #define __SPARC64_SPINLOCK_H |
| 8 | |
| 9 | #include <linux/config.h> |
| 10 | #include <linux/threads.h> /* For NR_CPUS */ |
| 11 | |
| 12 | #ifndef __ASSEMBLY__ |
| 13 | |
| 14 | /* To get debugging spinlocks which detect and catch |
| 15 | * deadlock situations, set CONFIG_DEBUG_SPINLOCK |
| 16 | * and rebuild your kernel. |
| 17 | */ |
| 18 | |
| 19 | /* All of these locking primitives are expected to work properly |
| 20 | * even in an RMO memory model, which currently is what the kernel |
| 21 | * runs in. |
| 22 | * |
| 23 | * There is another issue. Because we play games to save cycles |
| 24 | * in the non-contention case, we need to be extra careful about |
| 25 | * branch targets into the "spinning" code. They live in their |
| 26 | * own section, but the newer V9 branches have a shorter range |
| 27 | * than the traditional 32-bit sparc branch variants. The rule |
| 28 | * is that the branches that go into and out of the spinner sections |
| 29 | * must be pre-V9 branches. |
| 30 | */ |
| 31 | |
| 32 | #ifndef CONFIG_DEBUG_SPINLOCK |
| 33 | |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 34 | typedef struct { |
| 35 | volatile unsigned char lock; |
| 36 | #ifdef CONFIG_PREEMPT |
| 37 | unsigned int break_lock; |
| 38 | #endif |
| 39 | } spinlock_t; |
| 40 | #define SPIN_LOCK_UNLOCKED (spinlock_t) {0,} |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 42 | #define spin_lock_init(lp) do { *(lp)= SPIN_LOCK_UNLOCKED; } while(0) |
| 43 | #define spin_is_locked(lp) ((lp)->lock != 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 45 | #define spin_unlock_wait(lp) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | do { membar("#LoadLoad"); \ |
David S. Miller | 9a59c18 | 2005-04-24 21:04:02 -0700 | [diff] [blame] | 47 | } while((lp)->lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
| 49 | static inline void _raw_spin_lock(spinlock_t *lock) |
| 50 | { |
| 51 | unsigned long tmp; |
| 52 | |
| 53 | __asm__ __volatile__( |
| 54 | "1: ldstub [%1], %0\n" |
| 55 | " brnz,pn %0, 2f\n" |
| 56 | " membar #StoreLoad | #StoreStore\n" |
| 57 | " .subsection 2\n" |
| 58 | "2: ldub [%1], %0\n" |
| 59 | " brnz,pt %0, 2b\n" |
| 60 | " membar #LoadLoad\n" |
| 61 | " ba,a,pt %%xcc, 1b\n" |
| 62 | " .previous" |
| 63 | : "=&r" (tmp) |
| 64 | : "r" (lock) |
| 65 | : "memory"); |
| 66 | } |
| 67 | |
| 68 | static inline int _raw_spin_trylock(spinlock_t *lock) |
| 69 | { |
| 70 | unsigned long result; |
| 71 | |
| 72 | __asm__ __volatile__( |
| 73 | " ldstub [%1], %0\n" |
| 74 | " membar #StoreLoad | #StoreStore" |
| 75 | : "=r" (result) |
| 76 | : "r" (lock) |
| 77 | : "memory"); |
| 78 | |
| 79 | return (result == 0UL); |
| 80 | } |
| 81 | |
| 82 | static inline void _raw_spin_unlock(spinlock_t *lock) |
| 83 | { |
| 84 | __asm__ __volatile__( |
| 85 | " membar #StoreStore | #LoadStore\n" |
| 86 | " stb %%g0, [%0]" |
| 87 | : /* No outputs */ |
| 88 | : "r" (lock) |
| 89 | : "memory"); |
| 90 | } |
| 91 | |
| 92 | static inline void _raw_spin_lock_flags(spinlock_t *lock, unsigned long flags) |
| 93 | { |
| 94 | unsigned long tmp1, tmp2; |
| 95 | |
| 96 | __asm__ __volatile__( |
| 97 | "1: ldstub [%2], %0\n" |
| 98 | " brnz,pn %0, 2f\n" |
| 99 | " membar #StoreLoad | #StoreStore\n" |
| 100 | " .subsection 2\n" |
| 101 | "2: rdpr %%pil, %1\n" |
| 102 | " wrpr %3, %%pil\n" |
| 103 | "3: ldub [%2], %0\n" |
| 104 | " brnz,pt %0, 3b\n" |
| 105 | " membar #LoadLoad\n" |
| 106 | " ba,pt %%xcc, 1b\n" |
| 107 | " wrpr %1, %%pil\n" |
| 108 | " .previous" |
| 109 | : "=&r" (tmp1), "=&r" (tmp2) |
| 110 | : "r"(lock), "r"(flags) |
| 111 | : "memory"); |
| 112 | } |
| 113 | |
| 114 | #else /* !(CONFIG_DEBUG_SPINLOCK) */ |
| 115 | |
| 116 | typedef struct { |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 117 | volatile unsigned char lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | unsigned int owner_pc, owner_cpu; |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 119 | #ifdef CONFIG_PREEMPT |
| 120 | unsigned int break_lock; |
| 121 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | } spinlock_t; |
| 123 | #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0, 0xff } |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 124 | #define spin_lock_init(lp) do { *(lp)= SPIN_LOCK_UNLOCKED; } while(0) |
| 125 | #define spin_is_locked(__lock) ((__lock)->lock != 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | #define spin_unlock_wait(__lock) \ |
| 127 | do { \ |
| 128 | membar("#LoadLoad"); \ |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 129 | } while((__lock)->lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
| 131 | extern void _do_spin_lock (spinlock_t *lock, char *str); |
| 132 | extern void _do_spin_unlock (spinlock_t *lock); |
| 133 | extern int _do_spin_trylock (spinlock_t *lock); |
| 134 | |
| 135 | #define _raw_spin_trylock(lp) _do_spin_trylock(lp) |
| 136 | #define _raw_spin_lock(lock) _do_spin_lock(lock, "spin_lock") |
| 137 | #define _raw_spin_unlock(lock) _do_spin_unlock(lock) |
| 138 | #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) |
| 139 | |
| 140 | #endif /* CONFIG_DEBUG_SPINLOCK */ |
| 141 | |
| 142 | /* Multi-reader locks, these are much saner than the 32-bit Sparc ones... */ |
| 143 | |
| 144 | #ifndef CONFIG_DEBUG_SPINLOCK |
| 145 | |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 146 | typedef struct { |
| 147 | volatile unsigned int lock; |
| 148 | #ifdef CONFIG_PREEMPT |
| 149 | unsigned int break_lock; |
| 150 | #endif |
| 151 | } rwlock_t; |
David S. Miller | 9a59c18 | 2005-04-24 21:04:02 -0700 | [diff] [blame] | 152 | #define RW_LOCK_UNLOCKED (rwlock_t) {0,} |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | #define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0) |
| 154 | |
| 155 | static void inline __read_lock(rwlock_t *lock) |
| 156 | { |
| 157 | unsigned long tmp1, tmp2; |
| 158 | |
| 159 | __asm__ __volatile__ ( |
| 160 | "1: ldsw [%2], %0\n" |
| 161 | " brlz,pn %0, 2f\n" |
| 162 | "4: add %0, 1, %1\n" |
| 163 | " cas [%2], %0, %1\n" |
| 164 | " cmp %0, %1\n" |
| 165 | " bne,pn %%icc, 1b\n" |
| 166 | " membar #StoreLoad | #StoreStore\n" |
| 167 | " .subsection 2\n" |
| 168 | "2: ldsw [%2], %0\n" |
| 169 | " brlz,pt %0, 2b\n" |
| 170 | " membar #LoadLoad\n" |
| 171 | " ba,a,pt %%xcc, 4b\n" |
| 172 | " .previous" |
| 173 | : "=&r" (tmp1), "=&r" (tmp2) |
| 174 | : "r" (lock) |
| 175 | : "memory"); |
| 176 | } |
| 177 | |
| 178 | static void inline __read_unlock(rwlock_t *lock) |
| 179 | { |
| 180 | unsigned long tmp1, tmp2; |
| 181 | |
| 182 | __asm__ __volatile__( |
| 183 | " membar #StoreLoad | #LoadLoad\n" |
| 184 | "1: lduw [%2], %0\n" |
| 185 | " sub %0, 1, %1\n" |
| 186 | " cas [%2], %0, %1\n" |
| 187 | " cmp %0, %1\n" |
| 188 | " bne,pn %%xcc, 1b\n" |
| 189 | " nop" |
| 190 | : "=&r" (tmp1), "=&r" (tmp2) |
| 191 | : "r" (lock) |
| 192 | : "memory"); |
| 193 | } |
| 194 | |
| 195 | static void inline __write_lock(rwlock_t *lock) |
| 196 | { |
| 197 | unsigned long mask, tmp1, tmp2; |
| 198 | |
| 199 | mask = 0x80000000UL; |
| 200 | |
| 201 | __asm__ __volatile__( |
| 202 | "1: lduw [%2], %0\n" |
| 203 | " brnz,pn %0, 2f\n" |
| 204 | "4: or %0, %3, %1\n" |
| 205 | " cas [%2], %0, %1\n" |
| 206 | " cmp %0, %1\n" |
| 207 | " bne,pn %%icc, 1b\n" |
| 208 | " membar #StoreLoad | #StoreStore\n" |
| 209 | " .subsection 2\n" |
| 210 | "2: lduw [%2], %0\n" |
| 211 | " brnz,pt %0, 2b\n" |
| 212 | " membar #LoadLoad\n" |
| 213 | " ba,a,pt %%xcc, 4b\n" |
| 214 | " .previous" |
| 215 | : "=&r" (tmp1), "=&r" (tmp2) |
| 216 | : "r" (lock), "r" (mask) |
| 217 | : "memory"); |
| 218 | } |
| 219 | |
| 220 | static void inline __write_unlock(rwlock_t *lock) |
| 221 | { |
| 222 | __asm__ __volatile__( |
| 223 | " membar #LoadStore | #StoreStore\n" |
| 224 | " stw %%g0, [%0]" |
| 225 | : /* no outputs */ |
| 226 | : "r" (lock) |
| 227 | : "memory"); |
| 228 | } |
| 229 | |
| 230 | static int inline __write_trylock(rwlock_t *lock) |
| 231 | { |
| 232 | unsigned long mask, tmp1, tmp2, result; |
| 233 | |
| 234 | mask = 0x80000000UL; |
| 235 | |
| 236 | __asm__ __volatile__( |
| 237 | " mov 0, %2\n" |
| 238 | "1: lduw [%3], %0\n" |
| 239 | " brnz,pn %0, 2f\n" |
| 240 | " or %0, %4, %1\n" |
| 241 | " cas [%3], %0, %1\n" |
| 242 | " cmp %0, %1\n" |
| 243 | " bne,pn %%icc, 1b\n" |
| 244 | " membar #StoreLoad | #StoreStore\n" |
| 245 | " mov 1, %2\n" |
| 246 | "2:" |
| 247 | : "=&r" (tmp1), "=&r" (tmp2), "=&r" (result) |
| 248 | : "r" (lock), "r" (mask) |
| 249 | : "memory"); |
| 250 | |
| 251 | return result; |
| 252 | } |
| 253 | |
| 254 | #define _raw_read_lock(p) __read_lock(p) |
| 255 | #define _raw_read_unlock(p) __read_unlock(p) |
| 256 | #define _raw_write_lock(p) __write_lock(p) |
| 257 | #define _raw_write_unlock(p) __write_unlock(p) |
| 258 | #define _raw_write_trylock(p) __write_trylock(p) |
| 259 | |
| 260 | #else /* !(CONFIG_DEBUG_SPINLOCK) */ |
| 261 | |
| 262 | typedef struct { |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 263 | volatile unsigned long lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | unsigned int writer_pc, writer_cpu; |
| 265 | unsigned int reader_pc[NR_CPUS]; |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 266 | #ifdef CONFIG_PREEMPT |
| 267 | unsigned int break_lock; |
| 268 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | } rwlock_t; |
| 270 | #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, 0xff, { } } |
| 271 | #define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0) |
| 272 | |
| 273 | extern void _do_read_lock(rwlock_t *rw, char *str); |
| 274 | extern void _do_read_unlock(rwlock_t *rw, char *str); |
| 275 | extern void _do_write_lock(rwlock_t *rw, char *str); |
| 276 | extern void _do_write_unlock(rwlock_t *rw); |
| 277 | extern int _do_write_trylock(rwlock_t *rw, char *str); |
| 278 | |
| 279 | #define _raw_read_lock(lock) \ |
| 280 | do { unsigned long flags; \ |
| 281 | local_irq_save(flags); \ |
| 282 | _do_read_lock(lock, "read_lock"); \ |
| 283 | local_irq_restore(flags); \ |
| 284 | } while(0) |
| 285 | |
| 286 | #define _raw_read_unlock(lock) \ |
| 287 | do { unsigned long flags; \ |
| 288 | local_irq_save(flags); \ |
| 289 | _do_read_unlock(lock, "read_unlock"); \ |
| 290 | local_irq_restore(flags); \ |
| 291 | } while(0) |
| 292 | |
| 293 | #define _raw_write_lock(lock) \ |
| 294 | do { unsigned long flags; \ |
| 295 | local_irq_save(flags); \ |
| 296 | _do_write_lock(lock, "write_lock"); \ |
| 297 | local_irq_restore(flags); \ |
| 298 | } while(0) |
| 299 | |
| 300 | #define _raw_write_unlock(lock) \ |
| 301 | do { unsigned long flags; \ |
| 302 | local_irq_save(flags); \ |
| 303 | _do_write_unlock(lock); \ |
| 304 | local_irq_restore(flags); \ |
| 305 | } while(0) |
| 306 | |
| 307 | #define _raw_write_trylock(lock) \ |
| 308 | ({ unsigned long flags; \ |
| 309 | int val; \ |
| 310 | local_irq_save(flags); \ |
| 311 | val = _do_write_trylock(lock, "write_trylock"); \ |
| 312 | local_irq_restore(flags); \ |
| 313 | val; \ |
| 314 | }) |
| 315 | |
| 316 | #endif /* CONFIG_DEBUG_SPINLOCK */ |
| 317 | |
| 318 | #define _raw_read_trylock(lock) generic_raw_read_trylock(lock) |
Al Viro | 489ec5f | 2005-04-20 17:12:41 -0700 | [diff] [blame] | 319 | #define read_can_lock(rw) (!((rw)->lock & 0x80000000UL)) |
| 320 | #define write_can_lock(rw) (!(rw)->lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | |
| 322 | #endif /* !(__ASSEMBLY__) */ |
| 323 | |
| 324 | #endif /* !(__SPARC64_SPINLOCK_H) */ |