include/asm-sparc64/spinlock.h

   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 #ifndef __ASSEMBLY__
  10
  11 /* To get debugging spinlocks which detect and catch
  12  * deadlock situations, set DEBUG_SPINLOCKS in the sparc64
  13  * specific makefile and rebuild your kernel.
  14  */
  15
  16 /* All of these locking primitives are expected to work properly
  17  * even in an RMO memory model, which currently is what the kernel
  18  * runs in.
  19  *
  20  * There is another issue.  Because we play games to save cycles
  21  * in the non-contention case, we need to be extra careful about
  22  * branch targets into the "spinning" code.  They live in their
  23  * own section, but the newer V9 branches have a shorter range
  24  * than the traditional 32-bit sparc branch variants.  The rule
  25  * is that the branches that go into and out of the spinner sections
  26  * must be pre-V9 branches.
  27  */
  28
  29 #ifndef SPIN_LOCK_DEBUG
  30
  31 typedef unsigned char spinlock_t;
  32 #define SPIN_LOCK_UNLOCKED      0
  33
  34 #define spin_lock_init(lock)    (*((unsigned char *)(lock)) = 0)
  35 #define spin_is_locked(lock)    (*((volatile unsigned char *)(lock)) != 0)
  36
  37 #define spin_unlock_wait(lock)  \
  38 do {    membar("#LoadLoad");    \
  39 } while(*((volatile unsigned char *)lock))
  40
  41 extern __inline__ void spin_lock(spinlock_t *lock)
  42 {
  43         __asm__ __volatile__("
  44 1:      ldstub          [%0], %%g7
  45         brnz,pn         %%g7, 2f
  46          membar         #StoreLoad | #StoreStore
  47         .subsection     2
  48 2:      ldub            [%0], %%g7
  49         brnz,pt         %%g7, 2b
  50          membar         #LoadLoad
  51         b,a,pt          %%xcc, 1b
  52         .previous
  53 "       : /* no outputs */
  54         : "r" (lock)
  55         : "g7", "memory");
  56 }
  57
  58 extern __inline__ int spin_trylock(spinlock_t *lock)
  59 {
  60         unsigned int result;
  61         __asm__ __volatile__("ldstub [%1], %0\n\t"
  62                              "membar #StoreLoad | #StoreStore"
  63                              : "=r" (result)
  64                              : "r" (lock)
  65                              : "memory");
  66         return (result == 0);
  67 }
  68
  69 extern __inline__ void spin_unlock(spinlock_t *lock)
  70 {
  71         __asm__ __volatile__("membar    #StoreStore | #LoadStore\n\t"
  72                              "stb       %%g0, [%0]\n\t"
  73                              "membar    #StoreStore | #StoreLoad"
  74                              : /* No outputs */
  75                              : "r" (lock)
  76                              : "memory");
  77 }
  78
  79 extern __inline__ void spin_lock_irq(spinlock_t *lock)
  80 {
  81         __asm__ __volatile__("
  82         wrpr            %%g0, 15, %%pil
  83 1:      ldstub          [%0], %%g7
  84         brnz,pn         %%g7, 2f
  85          membar         #StoreLoad | #StoreStore
  86         .subsection     2
  87 2:      ldub            [%0], %%g7
  88         brnz,pt         %%g7, 2b
  89          membar         #LoadLoad
  90         b,a,pt          %%xcc, 1b
  91         .previous
  92 "       : /* no outputs */
  93         : "r" (lock)
  94         : "g7", "memory");
  95 }
  96
  97 extern __inline__ void spin_unlock_irq(spinlock_t *lock)
  98 {
  99         __asm__ __volatile__("membar    #StoreStore | #LoadStore\n\t"
 100                              "stb       %%g0, [%0]\n\t"
 101                              "membar    #StoreStore | #StoreLoad\n\t"
 102                              "wrpr      %%g0, 0x0, %%pil"
 103                              : /* no outputs */
 104                              : "r" (lock)
 105                              : "memory");
 106 }
 107
 108 #define spin_lock_bh(__lock)    \
 109 do {    local_bh_count++;       \
 110         spin_lock(__lock);      \
 111 } while(0)
 112
 113 #define spin_unlock_bh(__lock)          \
 114 do {    spin_unlock(__lock);            \
 115         local_bh_count--;               \
 116 } while(0)
 117
 118 #define spin_lock_irqsave(__lock, flags)                        \
 119 do {    register spinlock_t *__lp asm("g1");                    \
 120         __lp = (__lock);                                        \
 121         __asm__ __volatile__(                                   \
 122         "\n     rdpr            %%pil, %0\n"                    \
 123         "       wrpr            %%g0, 15, %%pil\n"              \
 124         "1:     ldstub          [%1], %%g7\n"                   \
 125         "       brnz,pn         %%g7, 2f\n"                     \
 126         "        membar         #StoreLoad | #StoreStore\n"     \
 127         "       .subsection     2\n"                            \
 128         "2:     ldub            [%1], %%g7\n"                   \
 129         "       brnz,pt         %%g7, 2b\n"                     \
 130         "        membar         #LoadLoad\n"                    \
 131         "       b,a,pt          %%xcc, 1b\n"                    \
 132         "       .previous\n"                                    \
 133         : "=&r" (flags)                                         \
 134         : "r" (__lp)                                            \
 135         : "g7", "memory");                                      \
 136 } while(0)
 137
 138 extern __inline__ void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
 139 {
 140         __asm__ __volatile__("membar    #StoreStore | #LoadStore\n\t"
 141                              "stb       %%g0, [%0]\n\t"
 142                              "membar    #StoreStore | #StoreLoad\n\t"
 143                              "wrpr      %1, 0x0, %%pil"
 144                              : /* no outputs */
 145                              : "r" (lock), "r" (flags)
 146                              : "memory");
 147 }
 148
 149 #else /* !(SPIN_LOCK_DEBUG) */
 150
 151 typedef struct {
 152         unsigned char lock;
 153         unsigned int owner_pc, owner_cpu;
 154 } spinlock_t;
 155 #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0, 0xff }
 156 #define spin_lock_init(__lock)  \
 157 do {    (__lock)->lock = 0; \
 158         (__lock)->owner_pc = 0; \
 159         (__lock)->owner_cpu = 0xff; \
 160 } while(0)
 161 #define spin_is_locked(__lock)  (*((volatile unsigned char *)(&((__lock)->lock))) != 0)
 162 #define spin_unlock_wait(__lock)        \
 163 do { \
 164         membar("#LoadLoad"); \
 165 } while(*((volatile unsigned char *)(&((__lock)->lock))))
 166
 167 extern void _do_spin_lock (spinlock_t *lock, char *str);
 168 extern void _do_spin_unlock (spinlock_t *lock);
 169 extern int _spin_trylock (spinlock_t *lock);
 170
 171 #define spin_trylock(lp)        _spin_trylock(lp)
 172 #define spin_lock(lock)         _do_spin_lock(lock, "spin_lock")
 173 #define spin_lock_irq(lock)     do { __cli(); _do_spin_lock(lock, "spin_lock_irq"); } while(0)
 174 #define spin_lock_bh(lock)      do { local_bh_count++; _do_spin_lock(lock, "spin_lock_bh"); } while(0)
 175 #define spin_lock_irqsave(lock, flags) do { __save_and_cli(flags); _do_spin_lock(lock, "spin_lock_irqsave"); } while(0)
 176 #define spin_unlock(lock)       _do_spin_unlock(lock)
 177 #define spin_unlock_irq(lock)   do { _do_spin_unlock(lock); __sti(); } while(0)
 178 #define spin_unlock_bh(lock)    do { _do_spin_unlock(lock); local_bh_count--; } while(0)
 179 #define spin_unlock_irqrestore(lock, flags) do { _do_spin_unlock(lock); __restore_flags(flags); } while(0)
 180
 181 #endif /* SPIN_LOCK_DEBUG */
 182
 183 /* Multi-reader locks, these are much saner than the 32-bit Sparc ones... */
 184
 185 #ifndef SPIN_LOCK_DEBUG
 186
 187 typedef unsigned int rwlock_t;
 188 #define RW_LOCK_UNLOCKED        0
 189
 190 #define read_lock(__rw_lck) \
 191 do {    register rwlock_t *__X asm("g1"); \
 192         __asm__ __volatile__("sethi     %%hi(__read_lock), %%g3\n\t" \
 193                              "jmpl      %%g3 + %%lo(__read_lock), %%g3\n\t" \
 194                              " nop\n1:" \
 195         : : "r" (__X = (__rw_lck)) \
 196           : "g3", "g5", "g7", "cc", "memory"); \
 197 } while(0)
 198
 199 #define read_unlock(__rw_lck) \
 200 do {    register rwlock_t *__X asm("g1"); \
 201         __asm__ __volatile__("sethi     %%hi(__read_unlock), %%g3\n\t" \
 202                              "jmpl      %%g3 + %%lo(__read_unlock), %%g3\n\t" \
 203                              " nop\n1:" \
 204         : : "r" (__X = (__rw_lck)) \
 205           : "g3", "g5", "g7", "cc", "memory"); \
 206 } while(0)
 207
 208 #define write_lock(__rw_lck) \
 209 do {    register rwlock_t *__X asm("g1"); \
 210         __asm__ __volatile__("sethi     %%hi(__write_lock), %%g3\n\t" \
 211                              "jmpl      %%g3 + %%lo(__write_lock), %%g3\n\t" \
 212                              " nop\n1:" \
 213         : : "r" (__X = (__rw_lck)) \
 214           : "g2", "g3", "g5", "g7", "cc", "memory"); \
 215 } while(0)
 216
 217 #define write_unlock(__rw_lck) \
 218 do {    register rwlock_t *__X asm("g1"); \
 219         __asm__ __volatile__("sethi     %%hi(__write_unlock), %%g3\n\t" \
 220                              "jmpl      %%g3 + %%lo(__write_unlock), %%g3\n\t" \
 221                              " nop\n1:" \
 222         : : "r" (__X = (__rw_lck)) \
 223           : "g2", "g3", "g5", "g7", "cc", "memory"); \
 224 } while(0)
 225
 226 #define read_lock_irq(lock)     do { __cli(); read_lock(lock); } while (0)
 227 #define read_unlock_irq(lock)   do { read_unlock(lock); __sti(); } while (0)
 228 #define read_lock_bh(lock)      do { local_bh_count++; read_lock(lock); } while (0)
 229 #define read_unlock_bh(lock)    do { read_unlock(lock); local_bh_count--; } while (0)
 230 #define write_lock_irq(lock)    do { __cli(); write_lock(lock); } while (0)
 231 #define write_unlock_irq(lock)  do { write_unlock(lock); __sti(); } while (0)
 232 #define write_lock_bh(lock)     do { local_bh_count++; write_lock(lock); } while (0)
 233 #define write_unlock_bh(lock)   do { write_unlock(lock); local_bh_count--; } while (0)
 234
 235 #define read_lock_irqsave(lock, flags)  \
 236         do { __save_and_cli(flags); read_lock(lock); } while (0)
 237 #define read_unlock_irqrestore(lock, flags) \
 238         do { read_unlock(lock); __restore_flags(flags); } while (0)
 239 #define write_lock_irqsave(lock, flags) \
 240         do { __save_and_cli(flags); write_lock(lock); } while (0)
 241 #define write_unlock_irqrestore(lock, flags) \
 242         do { write_unlock(lock); __restore_flags(flags); } while (0)
 243
 244 #else /* !(SPIN_LOCK_DEBUG) */
 245
 246 typedef struct {
 247         unsigned long lock;
 248         unsigned int writer_pc, writer_cpu;
 249         unsigned int reader_pc[4];
 250 } rwlock_t;
 251 #define RW_LOCK_UNLOCKED        (rwlock_t) { 0, 0, 0xff, { 0, 0, 0, 0 } }
 252
 253 extern void _do_read_lock(rwlock_t *rw, char *str);
 254 extern void _do_read_unlock(rwlock_t *rw, char *str);
 255 extern void _do_write_lock(rwlock_t *rw, char *str);
 256 extern void _do_write_unlock(rwlock_t *rw);
 257
 258 #define read_lock(lock) \
 259 do {    unsigned long flags; \
 260         __save_and_cli(flags); \
 261         _do_read_lock(lock, "read_lock"); \
 262         __restore_flags(flags); \
 263 } while(0)
 264 #define read_lock_irq(lock)     do { __cli(); _do_read_lock(lock, "read_lock_irq"); } while(0)
 265 #define read_lock_bh(lock)      do { local_bh_count++; _do_read_lock(lock, "read_lock_bh"); } while(0)
 266 #define read_lock_irqsave(lock, flags) do { __save_and_cli(flags); _do_read_lock(lock, "read_lock_irqsave"); } while(0)
 267
 268 #define read_unlock(lock) \
 269 do {    unsigned long flags; \
 270         __save_and_cli(flags); \
 271         _do_read_unlock(lock, "read_unlock"); \
 272         __restore_flags(flags); \
 273 } while(0)
 274 #define read_unlock_irq(lock)   do { _do_read_unlock(lock, "read_unlock_irq"); __sti() } while(0)
 275 #define read_unlock_bh(lock)    do { _do_read_unlock(lock, "read_unlock_bh"); local_bh_count--; } while(0)
 276 #define read_unlock_irqrestore(lock, flags) do { _do_read_unlock(lock, "read_unlock_irqrestore"); __restore_flags(flags); } while(0)
 277
 278 #define write_lock(lock) \
 279 do {    unsigned long flags; \
 280         __save_and_cli(flags); \
 281         _do_write_lock(lock, "write_lock"); \
 282         __restore_flags(flags); \
 283 } while(0)
 284 #define write_lock_irq(lock)    do { __cli(); _do_write_lock(lock, "write_lock_irq"); } while(0)
 285 #define write_lock_bh(lock)     do { local_bh_count++; _do_write_lock(lock, "write_lock_bh"); } while(0)
 286 #define write_lock_irqsave(lock, flags) do { __save_and_cli(flags); _do_write_lock(lock, "write_lock_irqsave"); } while(0)
 287
 288 #define write_unlock(lock) \
 289 do {    unsigned long flags; \
 290         __save_and_cli(flags); \
 291         _do_write_unlock(lock); \
 292         __restore_flags(flags); \
 293 } while(0)
 294 #define write_unlock_irq(lock)  do { _do_write_unlock(lock); __sti(); } while(0)
 295 #define write_unlock_bh(lock)   do { _do_write_unlock(lock); local_bh_count--; } while(0)
 296 #define write_unlock_irqrestore(lock, flags) do { _do_write_unlock(lock); __restore_flags(flags); } while(0)
 297
 298 #endif /* SPIN_LOCK_DEBUG */
 299
 300 #endif /* !(__ASSEMBLY__) */
 301
 302 #endif /* !(__SPARC64_SPINLOCK_H) */