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    arch=r4000                              \n"
  39                 "1:"    __LL    "%1, %2         # local_add_return      \n"
  40                 "       addu    %0, %1, %3                              \n"
  41                         __SC    "%0, %2                                 \n"
  42                 "       beqzl   %0, 1b                                  \n"
  43                 "       addu    %0, %1, %3                              \n"
  44                 "       .set    mips0                                   \n"
  45                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  46                 : "Ir" (i), "m" (l->a.counter)
  47                 : "memory");
  48         } else if (kernel_uses_llsc) {
  49                 unsigned long temp;
  50
  51                 __asm__ __volatile__(
  52                 "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
  53                 "1:"    __LL    "%1, %2         # local_add_return      \n"
  54                 "       addu    %0, %1, %3                              \n"
  55                         __SC    "%0, %2                                 \n"
  56                 "       beqz    %0, 1b                                  \n"
  57                 "       addu    %0, %1, %3                              \n"
  58                 "       .set    mips0                                   \n"
  59                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  60                 : "Ir" (i), "m" (l->a.counter)
  61                 : "memory");
  62         } else {
  63                 unsigned long flags;
  64
  65                 local_irq_save(flags);
  66                 result = l->a.counter;
  67                 result += i;
  68                 l->a.counter = result;
  69                 local_irq_restore(flags);
  70         }
  71
  72         return result;
  73 }
  74
  75 static __inline__ long local_sub_return(long i, local_t * l)
  76 {
  77         unsigned long result;
  78
  79         if (kernel_uses_llsc && R10000_LLSC_WAR) {
  80                 unsigned long temp;
  81
  82                 __asm__ __volatile__(
  83                 "       .set    arch=r4000                              \n"
  84                 "1:"    __LL    "%1, %2         # local_sub_return      \n"
  85                 "       subu    %0, %1, %3                              \n"
  86                         __SC    "%0, %2                                 \n"
  87                 "       beqzl   %0, 1b                                  \n"
  88                 "       subu    %0, %1, %3                              \n"
  89                 "       .set    mips0                                   \n"
  90                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
  91                 : "Ir" (i), "m" (l->a.counter)
  92                 : "memory");
  93         } else if (kernel_uses_llsc) {
  94                 unsigned long temp;
  95
  96                 __asm__ __volatile__(
  97                 "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
  98                 "1:"    __LL    "%1, %2         # local_sub_return      \n"
  99                 "       subu    %0, %1, %3                              \n"
 100                         __SC    "%0, %2                                 \n"
 101                 "       beqz    %0, 1b                                  \n"
 102                 "       subu    %0, %1, %3                              \n"
 103                 "       .set    mips0                                   \n"
 104                 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
 105                 : "Ir" (i), "m" (l->a.counter)
 106                 : "memory");
 107         } else {
 108                 unsigned long flags;
 109
 110                 local_irq_save(flags);
 111                 result = l->a.counter;
 112                 result -= i;
 113                 l->a.counter = result;
 114                 local_irq_restore(flags);
 115         }
 116
 117         return result;
 118 }
 119
 120 #define local_cmpxchg(l, o, n) \
 121         ((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
 122 #define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
 123
 124 /**
 125  * local_add_unless - add unless the number is a given value
 126  * @l: pointer of type local_t
 127  * @a: the amount to add to l...
 128  * @u: ...unless l is equal to u.
 129  *
 130  * Atomically adds @a to @l, so long as it was not @u.
 131  * Returns non-zero if @l was not @u, and zero otherwise.
 132  */
 133 #define local_add_unless(l, a, u)                               \
 134 ({                                                              \
 135         long c, old;                                            \
 136         c = local_read(l);                                      \
 137         while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
 138                 c = old;                                        \
 139         c != (u);                                               \
 140 })
 141 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
 142
 143 #define local_dec_return(l) local_sub_return(1, (l))
 144 #define local_inc_return(l) local_add_return(1, (l))
 145
 146 /*
 147  * local_sub_and_test - subtract value from variable and test result
 148  * @i: integer value to subtract
 149  * @l: pointer of type local_t
 150  *
 151  * Atomically subtracts @i from @l and returns
 152  * true if the result is zero, or false for all
 153  * other cases.
 154  */
 155 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
 156
 157 /*
 158  * local_inc_and_test - increment and test
 159  * @l: pointer of type local_t
 160  *
 161  * Atomically increments @l by 1
 162  * and returns true if the result is zero, or false for all
 163  * other cases.
 164  */
 165 #define local_inc_and_test(l) (local_inc_return(l) == 0)
 166
 167 /*
 168  * local_dec_and_test - decrement by 1 and test
 169  * @l: pointer of type local_t
 170  *
 171  * Atomically decrements @l by 1 and
 172  * returns true if the result is 0, or false for all other
 173  * cases.
 174  */
 175 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
 176
 177 /*
 178  * local_add_negative - add and test if negative
 179  * @l: pointer of type local_t
 180  * @i: integer value to add
 181  *
 182  * Atomically adds @i to @l and returns true
 183  * if the result is negative, or false when
 184  * result is greater than or equal to zero.
 185  */
 186 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
 187
 188 /* Use these for per-cpu local_t variables: on some archs they are
 189  * much more efficient than these naive implementations.  Note they take
 190  * a variable, not an address.
 191  */
 192
 193 #define __local_inc(l)          ((l)->a.counter++)
 194 #define __local_dec(l)          ((l)->a.counter++)
 195 #define __local_add(i, l)       ((l)->a.counter+=(i))
 196 #define __local_sub(i, l)       ((l)->a.counter-=(i))
 197
 198 #endif /* _ARCH_MIPS_LOCAL_H */