arch/mips/include/asm/local.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ARCH_MIPS_LOCAL_H
   3 #define _ARCH_MIPS_LOCAL_H
   4
   5 #include <linux/percpu.h>
   6 #include <linux/bitops.h>
   7 #include <linux/atomic.h>
   8 #include <asm/cmpxchg.h>
   9 #include <asm/compiler.h>
  10 #include <asm/war.h>
  11
  12 typedef struct
  13 {
  14         atomic_long_t a;
  15 } local_t;
  16
  17 #define LOCAL_INIT(i)   { ATOMIC_LONG_INIT(i) }
  18
  19 #define local_read(l)   atomic_long_read(&(l)->a)
  20 #define local_set(l, i) atomic_long_set(&(l)->a, (i))
  21
  22 #define local_add(i, l) atomic_long_add((i), (&(l)->a))
  23 #define local_sub(i, l) atomic_long_sub((i), (&(l)->a))
  24 #define local_inc(l)    atomic_long_inc(&(l)->a)
  25 #define local_dec(l)    atomic_long_dec(&(l)->a)
  26
  27 /*
  28  * Same as above, but return the result value
  29  */
  30 static __inline__ long local_add_return(long i, local_t * l)
  31 {
  32         unsigned long result;
  33
  34         if (kernel_uses_llsc && R10000_LLSC_WAR) {
  35                 unsigned long temp;
  36
  37                 __asm__ __volatile__(
  38                 "       .set    push                                    \n"
  39                 "       .set    arch=r4000                              \n"
  40                         __SYNC(full, loongson3_war) "                   \n"
  41                 "1:"    __LL    "%1, %2         # local_add_return      \n"
  42                 "       addu    %0, %1, %3                              \n"
  43                         __SC    "%0, %2                                 \n"
  44                 "       beqzl   %0, 1b                                  \n"
  45                 "       addu    %0, %1, %3                              \n"
  46                 "       .set    pop                                     \n"
  47                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  48                 : "Ir" (i), "m" (l->a.counter)
  49                 : "memory");
  50         } else if (kernel_uses_llsc) {
  51                 unsigned long temp;
  52
  53                 __asm__ __volatile__(
  54                 "       .set    push                                    \n"
  55                 "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
  56                         __SYNC(full, loongson3_war) "                   \n"
  57                 "1:"    __LL    "%1, %2         # local_add_return      \n"
  58                 "       addu    %0, %1, %3                              \n"
  59                         __SC    "%0, %2                                 \n"
  60                 "       beqz    %0, 1b                                  \n"
  61                 "       addu    %0, %1, %3                              \n"
  62                 "       .set    pop                                     \n"
  63                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  64                 : "Ir" (i), "m" (l->a.counter)
  65                 : "memory");
  66         } else {
  67                 unsigned long flags;
  68
  69                 local_irq_save(flags);
  70                 result = l->a.counter;
  71                 result += i;
  72                 l->a.counter = result;
  73                 local_irq_restore(flags);
  74         }
  75
  76         return result;
  77 }
  78
  79 static __inline__ long local_sub_return(long i, local_t * l)
  80 {
  81         unsigned long result;
  82
  83         if (kernel_uses_llsc && R10000_LLSC_WAR) {
  84                 unsigned long temp;
  85
  86                 __asm__ __volatile__(
  87                 "       .set    push                                    \n"
  88                 "       .set    arch=r4000                              \n"
  89                         __SYNC(full, loongson3_war) "                   \n"
  90                 "1:"    __LL    "%1, %2         # local_sub_return      \n"
  91                 "       subu    %0, %1, %3                              \n"
  92                         __SC    "%0, %2                                 \n"
  93                 "       beqzl   %0, 1b                                  \n"
  94                 "       subu    %0, %1, %3                              \n"
  95                 "       .set    pop                                     \n"
  96                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  97                 : "Ir" (i), "m" (l->a.counter)
  98                 : "memory");
  99         } else if (kernel_uses_llsc) {
 100                 unsigned long temp;
 101
 102                 __asm__ __volatile__(
 103                 "       .set    push                                    \n"
 104                 "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
 105                         __SYNC(full, loongson3_war) "                   \n"
 106                 "1:"    __LL    "%1, %2         # local_sub_return      \n"
 107                 "       subu    %0, %1, %3                              \n"
 108                         __SC    "%0, %2                                 \n"
 109                 "       beqz    %0, 1b                                  \n"
 110                 "       subu    %0, %1, %3                              \n"
 111                 "       .set    pop                                     \n"
 112                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
 113                 : "Ir" (i), "m" (l->a.counter)
 114                 : "memory");
 115         } else {
 116                 unsigned long flags;
 117
 118                 local_irq_save(flags);
 119                 result = l->a.counter;
 120                 result -= i;
 121                 l->a.counter = result;
 122                 local_irq_restore(flags);
 123         }
 124
 125         return result;
 126 }
 127
 128 #define local_cmpxchg(l, o, n) \
 129         ((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
 130 #define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
 131
 132 /**
 133  * local_add_unless - add unless the number is a given value
 134  * @l: pointer of type local_t
 135  * @a: the amount to add to l...
 136  * @u: ...unless l is equal to u.
 137  *
 138  * Atomically adds @a to @l, so long as it was not @u.
 139  * Returns non-zero if @l was not @u, and zero otherwise.
 140  */
 141 #define local_add_unless(l, a, u)                               \
 142 ({                                                              \
 143         long c, old;                                            \
 144         c = local_read(l);                                      \
 145         while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
 146                 c = old;                                        \
 147         c != (u);                                               \
 148 })
 149 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
 150
 151 #define local_dec_return(l) local_sub_return(1, (l))
 152 #define local_inc_return(l) local_add_return(1, (l))
 153
 154 /*
 155  * local_sub_and_test - subtract value from variable and test result
 156  * @i: integer value to subtract
 157  * @l: pointer of type local_t
 158  *
 159  * Atomically subtracts @i from @l and returns
 160  * true if the result is zero, or false for all
 161  * other cases.
 162  */
 163 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
 164
 165 /*
 166  * local_inc_and_test - increment and test
 167  * @l: pointer of type local_t
 168  *
 169  * Atomically increments @l by 1
 170  * and returns true if the result is zero, or false for all
 171  * other cases.
 172  */
 173 #define local_inc_and_test(l) (local_inc_return(l) == 0)
 174
 175 /*
 176  * local_dec_and_test - decrement by 1 and test
 177  * @l: pointer of type local_t
 178  *
 179  * Atomically decrements @l by 1 and
 180  * returns true if the result is 0, or false for all other
 181  * cases.
 182  */
 183 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
 184
 185 /*
 186  * local_add_negative - add and test if negative
 187  * @l: pointer of type local_t
 188  * @i: integer value to add
 189  *
 190  * Atomically adds @i to @l and returns true
 191  * if the result is negative, or false when
 192  * result is greater than or equal to zero.
 193  */
 194 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
 195
 196 /* Use these for per-cpu local_t variables: on some archs they are
 197  * much more efficient than these naive implementations.  Note they take
 198  * a variable, not an address.
 199  */
 200
 201 #define __local_inc(l)          ((l)->a.counter++)
 202 #define __local_dec(l)          ((l)->a.counter++)
 203 #define __local_add(i, l)       ((l)->a.counter+=(i))
 204 #define __local_sub(i, l)       ((l)->a.counter-=(i))
 205
 206 #endif /* _ARCH_MIPS_LOCAL_H */