arch/arm64/include/asm/atomic.h

   1 /*
   2  * Based on arch/arm/include/asm/atomic.h
   3  *
   4  * Copyright (C) 1996 Russell King.
   5  * Copyright (C) 2002 Deep Blue Solutions Ltd.
   6  * Copyright (C) 2012 ARM Ltd.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20 #ifndef __ASM_ATOMIC_H
  21 #define __ASM_ATOMIC_H
  22
  23 #include <linux/compiler.h>
  24 #include <linux/types.h>
  25
  26 #include <asm/barrier.h>
  27 #include <asm/lse.h>
  28
  29 #ifdef __KERNEL__
  30
  31 #define __ARM64_IN_ATOMIC_IMPL
  32
  33 #if defined(CONFIG_ARM64_LSE_ATOMICS) && defined(CONFIG_AS_LSE)
  34 #include <asm/atomic_lse.h>
  35 #else
  36 #include <asm/atomic_ll_sc.h>
  37 #endif
  38
  39 #undef __ARM64_IN_ATOMIC_IMPL
  40
  41 #include <asm/cmpxchg.h>
  42
  43 #define ___atomic_add_unless(v, a, u, sfx)                              \
  44 ({                                                                      \
  45         typeof((v)->counter) c, old;                                    \
  46                                                                         \
  47         c = atomic##sfx##_read(v);                                      \
  48         while (c != (u) &&                                              \
  49               (old = atomic##sfx##_cmpxchg((v), c, c + (a))) != c)      \
  50                 c = old;                                                \
  51         c;                                                              \
  52  })
  53
  54 #define ATOMIC_INIT(i)  { (i) }
  55
  56 #define atomic_read(v)                  READ_ONCE((v)->counter)
  57 #define atomic_set(v, i)                WRITE_ONCE(((v)->counter), (i))
  58 #define atomic_xchg(v, new)             xchg(&((v)->counter), (new))
  59 #define atomic_cmpxchg(v, old, new)     cmpxchg(&((v)->counter), (old), (new))
  60
  61 #define atomic_inc(v)                   atomic_add(1, (v))
  62 #define atomic_dec(v)                   atomic_sub(1, (v))
  63 #define atomic_inc_return(v)            atomic_add_return(1, (v))
  64 #define atomic_dec_return(v)            atomic_sub_return(1, (v))
  65 #define atomic_inc_and_test(v)          (atomic_inc_return(v) == 0)
  66 #define atomic_dec_and_test(v)          (atomic_dec_return(v) == 0)
  67 #define atomic_sub_and_test(i, v)       (atomic_sub_return((i), (v)) == 0)
  68 #define atomic_add_negative(i, v)       (atomic_add_return((i), (v)) < 0)
  69 #define __atomic_add_unless(v, a, u)    ___atomic_add_unless(v, a, u,)
  70 #define atomic_andnot                   atomic_andnot
  71
  72 /*
  73  * 64-bit atomic operations.
  74  */
  75 #define ATOMIC64_INIT                   ATOMIC_INIT
  76 #define atomic64_read                   atomic_read
  77 #define atomic64_set                    atomic_set
  78 #define atomic64_xchg                   atomic_xchg
  79 #define atomic64_cmpxchg                atomic_cmpxchg
  80
  81 #define atomic64_inc(v)                 atomic64_add(1, (v))
  82 #define atomic64_dec(v)                 atomic64_sub(1, (v))
  83 #define atomic64_inc_return(v)          atomic64_add_return(1, (v))
  84 #define atomic64_dec_return(v)          atomic64_sub_return(1, (v))
  85 #define atomic64_inc_and_test(v)        (atomic64_inc_return(v) == 0)
  86 #define atomic64_dec_and_test(v)        (atomic64_dec_return(v) == 0)
  87 #define atomic64_sub_and_test(i, v)     (atomic64_sub_return((i), (v)) == 0)
  88 #define atomic64_add_negative(i, v)     (atomic64_add_return((i), (v)) < 0)
  89 #define atomic64_add_unless(v, a, u)    (___atomic_add_unless(v, a, u, 64) != u)
  90 #define atomic64_andnot                 atomic64_andnot
  91
  92 #define atomic64_inc_not_zero(v)        atomic64_add_unless((v), 1, 0)
  93
  94 #endif
  95 #endif