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/asm.h> 9 #include <asm/cmpxchg.h> 10 #include <asm/compiler.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) { 35 unsigned long temp; 36 37 __asm__ __volatile__( 38 " .set push \n" 39 " .set "MIPS_ISA_ARCH_LEVEL" \n" 40 __SYNC(full, loongson3_war) " \n" 41 "1:" __stringify(LONG_LL) " %1, %2 \n" 42 __stringify(LONG_ADDU) " %0, %1, %3 \n" 43 __stringify(LONG_SC) " %0, %2 \n" 44 __stringify(SC_BEQZ) " %0, 1b \n" 45 __stringify(LONG_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 { 51 unsigned long flags; 52 53 local_irq_save(flags); 54 result = l->a.counter; 55 result += i; 56 l->a.counter = result; 57 local_irq_restore(flags); 58 } 59 60 return result; 61 } 62 63 static __inline__ long local_sub_return(long i, local_t * l) 64 { 65 unsigned long result; 66 67 if (kernel_uses_llsc) { 68 unsigned long temp; 69 70 __asm__ __volatile__( 71 " .set push \n" 72 " .set "MIPS_ISA_ARCH_LEVEL" \n" 73 __SYNC(full, loongson3_war) " \n" 74 "1:" __stringify(LONG_LL) " %1, %2 \n" 75 __stringify(LONG_SUBU) " %0, %1, %3 \n" 76 __stringify(LONG_SUBU) " %0, %1, %3 \n" 77 __stringify(LONG_SC) " %0, %2 \n" 78 __stringify(SC_BEQZ) " %0, 1b \n" 79 __stringify(LONG_SUBU) " %0, %1, %3 \n" 80 " .set pop \n" 81 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter) 82 : "Ir" (i), "m" (l->a.counter) 83 : "memory"); 84 } else { 85 unsigned long flags; 86 87 local_irq_save(flags); 88 result = l->a.counter; 89 result -= i; 90 l->a.counter = result; 91 local_irq_restore(flags); 92 } 93 94 return result; 95 } 96 97 static __inline__ long local_cmpxchg(local_t *l, long old, long new) 98 { 99 return cmpxchg_local(&l->a.counter, old, new); 100 } 101 102 static __inline__ bool local_try_cmpxchg(local_t *l, long *old, long new) 103 { 104 return try_cmpxchg_local(&l->a.counter, 105 (typeof(l->a.counter) *) old, new); 106 } 107 108 #define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n))) 109 110 /** 111 * local_add_unless - add unless the number is already a given value 112 * @l: pointer of type local_t 113 * @a: the amount to add to l... 114 * @u: ...unless l is equal to u. 115 * 116 * Atomically adds @a to @l, if @v was not already @u. 117 * Returns true if the addition was done. 118 */ 119 static __inline__ bool 120 local_add_unless(local_t *l, long a, long u) 121 { 122 long c = local_read(l); 123 124 do { 125 if (unlikely(c == u)) 126 return false; 127 } while (!local_try_cmpxchg(l, &c, c + a)); 128 129 return true; 130 } 131 132 #define local_inc_not_zero(l) local_add_unless((l), 1, 0) 133 134 #define local_dec_return(l) local_sub_return(1, (l)) 135 #define local_inc_return(l) local_add_return(1, (l)) 136 137 /* 138 * local_sub_and_test - subtract value from variable and test result 139 * @i: integer value to subtract 140 * @l: pointer of type local_t 141 * 142 * Atomically subtracts @i from @l and returns 143 * true if the result is zero, or false for all 144 * other cases. 145 */ 146 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0) 147 148 /* 149 * local_inc_and_test - increment and test 150 * @l: pointer of type local_t 151 * 152 * Atomically increments @l by 1 153 * and returns true if the result is zero, or false for all 154 * other cases. 155 */ 156 #define local_inc_and_test(l) (local_inc_return(l) == 0) 157 158 /* 159 * local_dec_and_test - decrement by 1 and test 160 * @l: pointer of type local_t 161 * 162 * Atomically decrements @l by 1 and 163 * returns true if the result is 0, or false for all other 164 * cases. 165 */ 166 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0) 167 168 /* 169 * local_add_negative - add and test if negative 170 * @l: pointer of type local_t 171 * @i: integer value to add 172 * 173 * Atomically adds @i to @l and returns true 174 * if the result is negative, or false when 175 * result is greater than or equal to zero. 176 */ 177 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0) 178 179 /* Use these for per-cpu local_t variables: on some archs they are 180 * much more efficient than these naive implementations. Note they take 181 * a variable, not an address. 182 */ 183 184 #define __local_inc(l) ((l)->a.counter++) 185 #define __local_dec(l) ((l)->a.counter++) 186 #define __local_add(i, l) ((l)->a.counter+=(i)) 187 #define __local_sub(i, l) ((l)->a.counter-=(i)) 188 189 #endif /* _ARCH_MIPS_LOCAL_H */ 190