include/asm-ia64/spinlock.h

   1 #ifndef _ASM_IA64_SPINLOCK_H
   2 #define _ASM_IA64_SPINLOCK_H
   3
   4 /*
   5  * Copyright (C) 1998-2003 Hewlett-Packard Co
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>
   7  * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
   8  *
   9  * This file is used for SMP configurations only.
  10  */
  11
  12 #include <linux/compiler.h>
  13 #include <linux/kernel.h>
  14
  15 #include <asm/atomic.h>
  16 #include <asm/bitops.h>
  17 #include <asm/intrinsics.h>
  18 #include <asm/system.h>
  19
  20 typedef struct {
  21         volatile unsigned int lock;
  22 #ifdef CONFIG_PREEMPT
  23         unsigned int break_lock;
  24 #endif
  25 } spinlock_t;
  26
  27 #define SPIN_LOCK_UNLOCKED                      (spinlock_t) { 0 }
  28 #define spin_lock_init(x)                       ((x)->lock = 0)
  29
  30 #ifdef ASM_SUPPORTED
  31 /*
  32  * Try to get the lock.  If we fail to get the lock, make a non-standard call to
  33  * ia64_spinlock_contention().  We do not use a normal call because that would force all
  34  * callers of spin_lock() to be non-leaf routines.  Instead, ia64_spinlock_contention() is
  35  * carefully coded to touch only those registers that spin_lock() marks "clobbered".
  36  */
  37
  38 #define IA64_SPINLOCK_CLOBBERS "ar.ccv", "ar.pfs", "p14", "p15", "r27", "r28", "r29", "r30", "b6", "memory"
  39
  40 static inline void
  41 _raw_spin_lock_flags (spinlock_t *lock, unsigned long flags)
  42 {
  43         register volatile unsigned int *ptr asm ("r31") = &lock->lock;
  44
  45 #if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 3)
  46 # ifdef CONFIG_ITANIUM
  47         /* don't use brl on Itanium... */
  48         asm volatile ("{\n\t"
  49                       "  mov ar.ccv = r0\n\t"
  50                       "  mov r28 = ip\n\t"
  51                       "  mov r30 = 1;;\n\t"
  52                       "}\n\t"
  53                       "cmpxchg4.acq r30 = [%1], r30, ar.ccv\n\t"
  54                       "movl r29 = ia64_spinlock_contention_pre3_4;;\n\t"
  55                       "cmp4.ne p14, p0 = r30, r0\n\t"
  56                       "mov b6 = r29;;\n\t"
  57                       "mov r27=%2\n\t"
  58                       "(p14) br.cond.spnt.many b6"
  59                       : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS);
  60 # else
  61         asm volatile ("{\n\t"
  62                       "  mov ar.ccv = r0\n\t"
  63                       "  mov r28 = ip\n\t"
  64                       "  mov r30 = 1;;\n\t"
  65                       "}\n\t"
  66                       "cmpxchg4.acq r30 = [%1], r30, ar.ccv;;\n\t"
  67                       "cmp4.ne p14, p0 = r30, r0\n\t"
  68                       "mov r27=%2\n\t"
  69                       "(p14) brl.cond.spnt.many ia64_spinlock_contention_pre3_4;;"
  70                       : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS);
  71 # endif /* CONFIG_MCKINLEY */
  72 #else
  73 # ifdef CONFIG_ITANIUM
  74         /* don't use brl on Itanium... */
  75         /* mis-declare, so we get the entry-point, not it's function descriptor: */
  76         asm volatile ("mov r30 = 1\n\t"
  77                       "mov r27=%2\n\t"
  78                       "mov ar.ccv = r0;;\n\t"
  79                       "cmpxchg4.acq r30 = [%0], r30, ar.ccv\n\t"
  80                       "movl r29 = ia64_spinlock_contention;;\n\t"
  81                       "cmp4.ne p14, p0 = r30, r0\n\t"
  82                       "mov b6 = r29;;\n\t"
  83                       "(p14) br.call.spnt.many b6 = b6"
  84                       : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS);
  85 # else
  86         asm volatile ("mov r30 = 1\n\t"
  87                       "mov r27=%2\n\t"
  88                       "mov ar.ccv = r0;;\n\t"
  89                       "cmpxchg4.acq r30 = [%0], r30, ar.ccv;;\n\t"
  90                       "cmp4.ne p14, p0 = r30, r0\n\t"
  91                       "(p14) brl.call.spnt.many b6=ia64_spinlock_contention;;"
  92                       : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS);
  93 # endif /* CONFIG_MCKINLEY */
  94 #endif
  95 }
  96 #define _raw_spin_lock(lock) _raw_spin_lock_flags(lock, 0)
  97 #else /* !ASM_SUPPORTED */
  98 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
  99 # define _raw_spin_lock(x)                                                              \
 100 do {                                                                                    \
 101         __u32 *ia64_spinlock_ptr = (__u32 *) (x);                                       \
 102         __u64 ia64_spinlock_val;                                                        \
 103         ia64_spinlock_val = ia64_cmpxchg4_acq(ia64_spinlock_ptr, 1, 0);                 \
 104         if (unlikely(ia64_spinlock_val)) {                                              \
 105                 do {                                                                    \
 106                         while (*ia64_spinlock_ptr)                                      \
 107                                 ia64_barrier();                                         \
 108                         ia64_spinlock_val = ia64_cmpxchg4_acq(ia64_spinlock_ptr, 1, 0); \
 109                 } while (ia64_spinlock_val);                                            \
 110         }                                                                               \
 111 } while (0)
 112 #endif /* !ASM_SUPPORTED */
 113
 114 #define spin_is_locked(x)       ((x)->lock != 0)
 115 #define _raw_spin_unlock(x)     do { barrier(); ((spinlock_t *) x)->lock = 0; } while (0)
 116 #define _raw_spin_trylock(x)    (cmpxchg_acq(&(x)->lock, 0, 1) == 0)
 117 #define spin_unlock_wait(x)     do { barrier(); } while ((x)->lock)
 118
 119 typedef struct {
 120         volatile unsigned int read_counter      : 31;
 121         volatile unsigned int write_lock        :  1;
 122 #ifdef CONFIG_PREEMPT
 123         unsigned int break_lock;
 124 #endif
 125 } rwlock_t;
 126 #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 }
 127
 128 #define rwlock_init(x)          do { *(x) = RW_LOCK_UNLOCKED; } while(0)
 129 #define read_can_lock(rw)       (*(volatile int *)(rw) >= 0)
 130 #define write_can_lock(rw)      (*(volatile int *)(rw) == 0)
 131
 132 #define _raw_read_lock(rw)                                                              \
 133 do {                                                                                    \
 134         rwlock_t *__read_lock_ptr = (rw);                                               \
 135                                                                                         \
 136         while (unlikely(ia64_fetchadd(1, (int *) __read_lock_ptr, acq) < 0)) {          \
 137                 ia64_fetchadd(-1, (int *) __read_lock_ptr, rel);                        \
 138                 while (*(volatile int *)__read_lock_ptr < 0)                            \
 139                         cpu_relax();                                                    \
 140         }                                                                               \
 141 } while (0)
 142
 143 #define _raw_read_unlock(rw)                                    \
 144 do {                                                            \
 145         rwlock_t *__read_lock_ptr = (rw);                       \
 146         ia64_fetchadd(-1, (int *) __read_lock_ptr, rel);        \
 147 } while (0)
 148
 149 #ifdef ASM_SUPPORTED
 150 #define _raw_write_lock(rw)                                                     \
 151 do {                                                                            \
 152         __asm__ __volatile__ (                                                  \
 153                 "mov ar.ccv = r0\n"                                             \
 154                 "dep r29 = -1, r0, 31, 1;;\n"                                   \
 155                 "1:\n"                                                          \
 156                 "ld4 r2 = [%0];;\n"                                             \
 157                 "cmp4.eq p0,p7 = r0,r2\n"                                       \
 158                 "(p7) br.cond.spnt.few 1b \n"                                   \
 159                 "cmpxchg4.acq r2 = [%0], r29, ar.ccv;;\n"                       \
 160                 "cmp4.eq p0,p7 = r0, r2\n"                                      \
 161                 "(p7) br.cond.spnt.few 1b;;\n"                                  \
 162                 :: "r"(rw) : "ar.ccv", "p7", "r2", "r29", "memory");            \
 163 } while(0)
 164
 165 #define _raw_write_trylock(rw)                                                  \
 166 ({                                                                              \
 167         register long result;                                                   \
 168                                                                                 \
 169         __asm__ __volatile__ (                                                  \
 170                 "mov ar.ccv = r0\n"                                             \
 171                 "dep r29 = -1, r0, 31, 1;;\n"                                   \
 172                 "cmpxchg4.acq %0 = [%1], r29, ar.ccv\n"                         \
 173                 : "=r"(result) : "r"(rw) : "ar.ccv", "r29", "memory");          \
 174         (result == 0);                                                          \
 175 })
 176
 177 #else /* !ASM_SUPPORTED */
 178
 179 #define _raw_write_lock(l)                                                              \
 180 ({                                                                                      \
 181         __u64 ia64_val, ia64_set_val = ia64_dep_mi(-1, 0, 31, 1);                       \
 182         __u32 *ia64_write_lock_ptr = (__u32 *) (l);                                     \
 183         do {                                                                            \
 184                 while (*ia64_write_lock_ptr)                                            \
 185                         ia64_barrier();                                                 \
 186                 ia64_val = ia64_cmpxchg4_acq(ia64_write_lock_ptr, ia64_set_val, 0);     \
 187         } while (ia64_val);                                                             \
 188 })
 189
 190 #define _raw_write_trylock(rw)                                          \
 191 ({                                                                      \
 192         __u64 ia64_val;                                                 \
 193         __u64 ia64_set_val = ia64_dep_mi(-1, 0, 31,1);                  \
 194         ia64_val = ia64_cmpxchg4_acq((__u32 *)(rw), ia64_set_val, 0);   \
 195         (ia64_val == 0);                                                \
 196 })
 197
 198 #endif /* !ASM_SUPPORTED */
 199
 200 #define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
 201
 202 #define _raw_write_unlock(x)                                                            \
 203 ({                                                                                      \
 204         smp_mb__before_clear_bit();     /* need barrier before releasing lock... */     \
 205         clear_bit(31, (x));                                                             \
 206 })
 207
 208 #endif /*  _ASM_IA64_SPINLOCK_H */