| /* | |
| * Atomic operations that C can't guarantee us. Useful for | |
| * resource counting etc.. | |
| * | |
| * But use these as seldom as possible since they are much more slower | |
| * than regular operations. | |
| * | |
| * This file is subject to the terms and conditions of the GNU General Public | |
| * License. See the file "COPYING" in the main directory of this archive | |
| * for more details. | |
| * | |
| * Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle | |
| */ | |
| #ifndef _ASM_ATOMIC_H | |
| #define _ASM_ATOMIC_H | |
| #include <linux/irqflags.h> | |
| #include <linux/types.h> | |
| #include <asm/barrier.h> | |
| #include <asm/compiler.h> | |
| #include <asm/cpu-features.h> | |
| #include <asm/cmpxchg.h> | |
| #include <asm/war.h> | |
| #define ATOMIC_INIT(i) { (i) } | |
| /* | |
| * atomic_read - read atomic variable | |
| * @v: pointer of type atomic_t | |
| * | |
| * Atomically reads the value of @v. | |
| */ | |
| #define atomic_read(v) READ_ONCE((v)->counter) | |
| /* | |
| * atomic_set - set atomic variable | |
| * @v: pointer of type atomic_t | |
| * @i: required value | |
| * | |
| * Atomically sets the value of @v to @i. | |
| */ | |
| #define atomic_set(v, i) WRITE_ONCE((v)->counter, (i)) | |
| #define ATOMIC_OP(op, c_op, asm_op) \ | |
| static __inline__ void atomic_##op(int i, atomic_t * v) \ | |
| { \ | |
| if (kernel_uses_llsc && R10000_LLSC_WAR) { \ | |
| int temp; \ | |
| \ | |
| __asm__ __volatile__( \ | |
| " .set arch=r4000 \n" \ | |
| "1: ll %0, %1 # atomic_" #op " \n" \ | |
| " " #asm_op " %0, %2 \n" \ | |
| " sc %0, %1 \n" \ | |
| " beqzl %0, 1b \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } else if (kernel_uses_llsc) { \ | |
| int temp; \ | |
| \ | |
| do { \ | |
| __asm__ __volatile__( \ | |
| " .set "MIPS_ISA_LEVEL" \n" \ | |
| " ll %0, %1 # atomic_" #op "\n" \ | |
| " " #asm_op " %0, %2 \n" \ | |
| " sc %0, %1 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } while (unlikely(!temp)); \ | |
| } else { \ | |
| unsigned long flags; \ | |
| \ | |
| raw_local_irq_save(flags); \ | |
| v->counter c_op i; \ | |
| raw_local_irq_restore(flags); \ | |
| } \ | |
| } | |
| #define ATOMIC_OP_RETURN(op, c_op, asm_op) \ | |
| static __inline__ int atomic_##op##_return_relaxed(int i, atomic_t * v) \ | |
| { \ | |
| int result; \ | |
| \ | |
| if (kernel_uses_llsc && R10000_LLSC_WAR) { \ | |
| int temp; \ | |
| \ | |
| __asm__ __volatile__( \ | |
| " .set arch=r4000 \n" \ | |
| "1: ll %1, %2 # atomic_" #op "_return \n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " sc %0, %2 \n" \ | |
| " beqzl %0, 1b \n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (result), "=&r" (temp), \ | |
| "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } else if (kernel_uses_llsc) { \ | |
| int temp; \ | |
| \ | |
| do { \ | |
| __asm__ __volatile__( \ | |
| " .set "MIPS_ISA_LEVEL" \n" \ | |
| " ll %1, %2 # atomic_" #op "_return \n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " sc %0, %2 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (result), "=&r" (temp), \ | |
| "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } while (unlikely(!result)); \ | |
| \ | |
| result = temp; result c_op i; \ | |
| } else { \ | |
| unsigned long flags; \ | |
| \ | |
| raw_local_irq_save(flags); \ | |
| result = v->counter; \ | |
| result c_op i; \ | |
| v->counter = result; \ | |
| raw_local_irq_restore(flags); \ | |
| } \ | |
| \ | |
| return result; \ | |
| } | |
| #define ATOMIC_FETCH_OP(op, c_op, asm_op) \ | |
| static __inline__ int atomic_fetch_##op##_relaxed(int i, atomic_t * v) \ | |
| { \ | |
| int result; \ | |
| \ | |
| if (kernel_uses_llsc && R10000_LLSC_WAR) { \ | |
| int temp; \ | |
| \ | |
| __asm__ __volatile__( \ | |
| " .set arch=r4000 \n" \ | |
| "1: ll %1, %2 # atomic_fetch_" #op " \n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " sc %0, %2 \n" \ | |
| " beqzl %0, 1b \n" \ | |
| " move %0, %1 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (result), "=&r" (temp), \ | |
| "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } else if (kernel_uses_llsc) { \ | |
| int temp; \ | |
| \ | |
| do { \ | |
| __asm__ __volatile__( \ | |
| " .set "MIPS_ISA_LEVEL" \n" \ | |
| " ll %1, %2 # atomic_fetch_" #op " \n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " sc %0, %2 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (result), "=&r" (temp), \ | |
| "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } while (unlikely(!result)); \ | |
| \ | |
| result = temp; \ | |
| } else { \ | |
| unsigned long flags; \ | |
| \ | |
| raw_local_irq_save(flags); \ | |
| result = v->counter; \ | |
| v->counter c_op i; \ | |
| raw_local_irq_restore(flags); \ | |
| } \ | |
| \ | |
| return result; \ | |
| } | |
| #define ATOMIC_OPS(op, c_op, asm_op) \ | |
| ATOMIC_OP(op, c_op, asm_op) \ | |
| ATOMIC_OP_RETURN(op, c_op, asm_op) \ | |
| ATOMIC_FETCH_OP(op, c_op, asm_op) | |
| ATOMIC_OPS(add, +=, addu) | |
| ATOMIC_OPS(sub, -=, subu) | |
| #define atomic_add_return_relaxed atomic_add_return_relaxed | |
| #define atomic_sub_return_relaxed atomic_sub_return_relaxed | |
| #define atomic_fetch_add_relaxed atomic_fetch_add_relaxed | |
| #define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed | |
| #undef ATOMIC_OPS | |
| #define ATOMIC_OPS(op, c_op, asm_op) \ | |
| ATOMIC_OP(op, c_op, asm_op) \ | |
| ATOMIC_FETCH_OP(op, c_op, asm_op) | |
| ATOMIC_OPS(and, &=, and) | |
| ATOMIC_OPS(or, |=, or) | |
| ATOMIC_OPS(xor, ^=, xor) | |
| #define atomic_fetch_and_relaxed atomic_fetch_and_relaxed | |
| #define atomic_fetch_or_relaxed atomic_fetch_or_relaxed | |
| #define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed | |
| #undef ATOMIC_OPS | |
| #undef ATOMIC_FETCH_OP | |
| #undef ATOMIC_OP_RETURN | |
| #undef ATOMIC_OP | |
| /* | |
| * atomic_sub_if_positive - conditionally subtract integer from atomic variable | |
| * @i: integer value to subtract | |
| * @v: pointer of type atomic_t | |
| * | |
| * Atomically test @v and subtract @i if @v is greater or equal than @i. | |
| * The function returns the old value of @v minus @i. | |
| */ | |
| static __inline__ int atomic_sub_if_positive(int i, atomic_t * v) | |
| { | |
| int result; | |
| smp_mb__before_llsc(); | |
| if (kernel_uses_llsc && R10000_LLSC_WAR) { | |
| int temp; | |
| __asm__ __volatile__( | |
| " .set arch=r4000 \n" | |
| "1: ll %1, %2 # atomic_sub_if_positive\n" | |
| " subu %0, %1, %3 \n" | |
| " bltz %0, 1f \n" | |
| " sc %0, %2 \n" | |
| " .set noreorder \n" | |
| " beqzl %0, 1b \n" | |
| " subu %0, %1, %3 \n" | |
| " .set reorder \n" | |
| "1: \n" | |
| " .set mips0 \n" | |
| : "=&r" (result), "=&r" (temp), | |
| "+" GCC_OFF_SMALL_ASM() (v->counter) | |
| : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) | |
| : "memory"); | |
| } else if (kernel_uses_llsc) { | |
| int temp; | |
| __asm__ __volatile__( | |
| " .set "MIPS_ISA_LEVEL" \n" | |
| "1: ll %1, %2 # atomic_sub_if_positive\n" | |
| " subu %0, %1, %3 \n" | |
| " bltz %0, 1f \n" | |
| " sc %0, %2 \n" | |
| " .set noreorder \n" | |
| " beqz %0, 1b \n" | |
| " subu %0, %1, %3 \n" | |
| " .set reorder \n" | |
| "1: \n" | |
| " .set mips0 \n" | |
| : "=&r" (result), "=&r" (temp), | |
| "+" GCC_OFF_SMALL_ASM() (v->counter) | |
| : "Ir" (i)); | |
| } else { | |
| unsigned long flags; | |
| raw_local_irq_save(flags); | |
| result = v->counter; | |
| result -= i; | |
| if (result >= 0) | |
| v->counter = result; | |
| raw_local_irq_restore(flags); | |
| } | |
| smp_llsc_mb(); | |
| return result; | |
| } | |
| #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) | |
| #define atomic_xchg(v, new) (xchg(&((v)->counter), (new))) | |
| /** | |
| * __atomic_add_unless - add unless the number is a given value | |
| * @v: pointer of type atomic_t | |
| * @a: the amount to add to v... | |
| * @u: ...unless v is equal to u. | |
| * | |
| * Atomically adds @a to @v, so long as it was not @u. | |
| * Returns the old value of @v. | |
| */ | |
| static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) | |
| { | |
| int c, old; | |
| c = atomic_read(v); | |
| for (;;) { | |
| if (unlikely(c == (u))) | |
| break; | |
| old = atomic_cmpxchg((v), c, c + (a)); | |
| if (likely(old == c)) | |
| break; | |
| c = old; | |
| } | |
| return c; | |
| } | |
| #define atomic_dec_return(v) atomic_sub_return(1, (v)) | |
| #define atomic_inc_return(v) atomic_add_return(1, (v)) | |
| /* | |
| * atomic_sub_and_test - subtract value from variable and test result | |
| * @i: integer value to subtract | |
| * @v: pointer of type atomic_t | |
| * | |
| * Atomically subtracts @i from @v and returns | |
| * true if the result is zero, or false for all | |
| * other cases. | |
| */ | |
| #define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) | |
| /* | |
| * atomic_inc_and_test - increment and test | |
| * @v: pointer of type atomic_t | |
| * | |
| * Atomically increments @v by 1 | |
| * and returns true if the result is zero, or false for all | |
| * other cases. | |
| */ | |
| #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) | |
| /* | |
| * atomic_dec_and_test - decrement by 1 and test | |
| * @v: pointer of type atomic_t | |
| * | |
| * Atomically decrements @v by 1 and | |
| * returns true if the result is 0, or false for all other | |
| * cases. | |
| */ | |
| #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) | |
| /* | |
| * atomic_dec_if_positive - decrement by 1 if old value positive | |
| * @v: pointer of type atomic_t | |
| */ | |
| #define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v) | |
| /* | |
| * atomic_inc - increment atomic variable | |
| * @v: pointer of type atomic_t | |
| * | |
| * Atomically increments @v by 1. | |
| */ | |
| #define atomic_inc(v) atomic_add(1, (v)) | |
| /* | |
| * atomic_dec - decrement and test | |
| * @v: pointer of type atomic_t | |
| * | |
| * Atomically decrements @v by 1. | |
| */ | |
| #define atomic_dec(v) atomic_sub(1, (v)) | |
| /* | |
| * atomic_add_negative - add and test if negative | |
| * @v: pointer of type atomic_t | |
| * @i: integer value to add | |
| * | |
| * Atomically adds @i to @v and returns true | |
| * if the result is negative, or false when | |
| * result is greater than or equal to zero. | |
| */ | |
| #define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0) | |
| #ifdef CONFIG_64BIT | |
| #define ATOMIC64_INIT(i) { (i) } | |
| /* | |
| * atomic64_read - read atomic variable | |
| * @v: pointer of type atomic64_t | |
| * | |
| */ | |
| #define atomic64_read(v) READ_ONCE((v)->counter) | |
| /* | |
| * atomic64_set - set atomic variable | |
| * @v: pointer of type atomic64_t | |
| * @i: required value | |
| */ | |
| #define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i)) | |
| #define ATOMIC64_OP(op, c_op, asm_op) \ | |
| static __inline__ void atomic64_##op(long i, atomic64_t * v) \ | |
| { \ | |
| if (kernel_uses_llsc && R10000_LLSC_WAR) { \ | |
| long temp; \ | |
| \ | |
| __asm__ __volatile__( \ | |
| " .set arch=r4000 \n" \ | |
| "1: lld %0, %1 # atomic64_" #op " \n" \ | |
| " " #asm_op " %0, %2 \n" \ | |
| " scd %0, %1 \n" \ | |
| " beqzl %0, 1b \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } else if (kernel_uses_llsc) { \ | |
| long temp; \ | |
| \ | |
| do { \ | |
| __asm__ __volatile__( \ | |
| " .set "MIPS_ISA_LEVEL" \n" \ | |
| " lld %0, %1 # atomic64_" #op "\n" \ | |
| " " #asm_op " %0, %2 \n" \ | |
| " scd %0, %1 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } while (unlikely(!temp)); \ | |
| } else { \ | |
| unsigned long flags; \ | |
| \ | |
| raw_local_irq_save(flags); \ | |
| v->counter c_op i; \ | |
| raw_local_irq_restore(flags); \ | |
| } \ | |
| } | |
| #define ATOMIC64_OP_RETURN(op, c_op, asm_op) \ | |
| static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v) \ | |
| { \ | |
| long result; \ | |
| \ | |
| if (kernel_uses_llsc && R10000_LLSC_WAR) { \ | |
| long temp; \ | |
| \ | |
| __asm__ __volatile__( \ | |
| " .set arch=r4000 \n" \ | |
| "1: lld %1, %2 # atomic64_" #op "_return\n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " scd %0, %2 \n" \ | |
| " beqzl %0, 1b \n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (result), "=&r" (temp), \ | |
| "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } else if (kernel_uses_llsc) { \ | |
| long temp; \ | |
| \ | |
| do { \ | |
| __asm__ __volatile__( \ | |
| " .set "MIPS_ISA_LEVEL" \n" \ | |
| " lld %1, %2 # atomic64_" #op "_return\n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " scd %0, %2 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (result), "=&r" (temp), \ | |
| "=" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "memory"); \ | |
| } while (unlikely(!result)); \ | |
| \ | |
| result = temp; result c_op i; \ | |
| } else { \ | |
| unsigned long flags; \ | |
| \ | |
| raw_local_irq_save(flags); \ | |
| result = v->counter; \ | |
| result c_op i; \ | |
| v->counter = result; \ | |
| raw_local_irq_restore(flags); \ | |
| } \ | |
| \ | |
| return result; \ | |
| } | |
| #define ATOMIC64_FETCH_OP(op, c_op, asm_op) \ | |
| static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v) \ | |
| { \ | |
| long result; \ | |
| \ | |
| if (kernel_uses_llsc && R10000_LLSC_WAR) { \ | |
| long temp; \ | |
| \ | |
| __asm__ __volatile__( \ | |
| " .set arch=r4000 \n" \ | |
| "1: lld %1, %2 # atomic64_fetch_" #op "\n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " scd %0, %2 \n" \ | |
| " beqzl %0, 1b \n" \ | |
| " move %0, %1 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (result), "=&r" (temp), \ | |
| "+" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i)); \ | |
| } else if (kernel_uses_llsc) { \ | |
| long temp; \ | |
| \ | |
| do { \ | |
| __asm__ __volatile__( \ | |
| " .set "MIPS_ISA_LEVEL" \n" \ | |
| " lld %1, %2 # atomic64_fetch_" #op "\n" \ | |
| " " #asm_op " %0, %1, %3 \n" \ | |
| " scd %0, %2 \n" \ | |
| " .set mips0 \n" \ | |
| : "=&r" (result), "=&r" (temp), \ | |
| "=" GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \ | |
| : "memory"); \ | |
| } while (unlikely(!result)); \ | |
| \ | |
| result = temp; \ | |
| } else { \ | |
| unsigned long flags; \ | |
| \ | |
| raw_local_irq_save(flags); \ | |
| result = v->counter; \ | |
| v->counter c_op i; \ | |
| raw_local_irq_restore(flags); \ | |
| } \ | |
| \ | |
| return result; \ | |
| } | |
| #define ATOMIC64_OPS(op, c_op, asm_op) \ | |
| ATOMIC64_OP(op, c_op, asm_op) \ | |
| ATOMIC64_OP_RETURN(op, c_op, asm_op) \ | |
| ATOMIC64_FETCH_OP(op, c_op, asm_op) | |
| ATOMIC64_OPS(add, +=, daddu) | |
| ATOMIC64_OPS(sub, -=, dsubu) | |
| #define atomic64_add_return_relaxed atomic64_add_return_relaxed | |
| #define atomic64_sub_return_relaxed atomic64_sub_return_relaxed | |
| #define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed | |
| #define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed | |
| #undef ATOMIC64_OPS | |
| #define ATOMIC64_OPS(op, c_op, asm_op) \ | |
| ATOMIC64_OP(op, c_op, asm_op) \ | |
| ATOMIC64_FETCH_OP(op, c_op, asm_op) | |
| ATOMIC64_OPS(and, &=, and) | |
| ATOMIC64_OPS(or, |=, or) | |
| ATOMIC64_OPS(xor, ^=, xor) | |
| #define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed | |
| #define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed | |
| #define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed | |
| #undef ATOMIC64_OPS | |
| #undef ATOMIC64_FETCH_OP | |
| #undef ATOMIC64_OP_RETURN | |
| #undef ATOMIC64_OP | |
| /* | |
| * atomic64_sub_if_positive - conditionally subtract integer from atomic | |
| * variable | |
| * @i: integer value to subtract | |
| * @v: pointer of type atomic64_t | |
| * | |
| * Atomically test @v and subtract @i if @v is greater or equal than @i. | |
| * The function returns the old value of @v minus @i. | |
| */ | |
| static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v) | |
| { | |
| long result; | |
| smp_mb__before_llsc(); | |
| if (kernel_uses_llsc && R10000_LLSC_WAR) { | |
| long temp; | |
| __asm__ __volatile__( | |
| " .set arch=r4000 \n" | |
| "1: lld %1, %2 # atomic64_sub_if_positive\n" | |
| " dsubu %0, %1, %3 \n" | |
| " bltz %0, 1f \n" | |
| " scd %0, %2 \n" | |
| " .set noreorder \n" | |
| " beqzl %0, 1b \n" | |
| " dsubu %0, %1, %3 \n" | |
| " .set reorder \n" | |
| "1: \n" | |
| " .set mips0 \n" | |
| : "=&r" (result), "=&r" (temp), | |
| "=" GCC_OFF_SMALL_ASM() (v->counter) | |
| : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) | |
| : "memory"); | |
| } else if (kernel_uses_llsc) { | |
| long temp; | |
| __asm__ __volatile__( | |
| " .set "MIPS_ISA_LEVEL" \n" | |
| "1: lld %1, %2 # atomic64_sub_if_positive\n" | |
| " dsubu %0, %1, %3 \n" | |
| " bltz %0, 1f \n" | |
| " scd %0, %2 \n" | |
| " .set noreorder \n" | |
| " beqz %0, 1b \n" | |
| " dsubu %0, %1, %3 \n" | |
| " .set reorder \n" | |
| "1: \n" | |
| " .set mips0 \n" | |
| : "=&r" (result), "=&r" (temp), | |
| "+" GCC_OFF_SMALL_ASM() (v->counter) | |
| : "Ir" (i)); | |
| } else { | |
| unsigned long flags; | |
| raw_local_irq_save(flags); | |
| result = v->counter; | |
| result -= i; | |
| if (result >= 0) | |
| v->counter = result; | |
| raw_local_irq_restore(flags); | |
| } | |
| smp_llsc_mb(); | |
| return result; | |
| } | |
| #define atomic64_cmpxchg(v, o, n) \ | |
| ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n))) | |
| #define atomic64_xchg(v, new) (xchg(&((v)->counter), (new))) | |
| /** | |
| * atomic64_add_unless - add unless the number is a given value | |
| * @v: pointer of type atomic64_t | |
| * @a: the amount to add to v... | |
| * @u: ...unless v is equal to u. | |
| * | |
| * Atomically adds @a to @v, so long as it was not @u. | |
| * Returns true iff @v was not @u. | |
| */ | |
| static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) | |
| { | |
| long c, old; | |
| c = atomic64_read(v); | |
| for (;;) { | |
| if (unlikely(c == (u))) | |
| break; | |
| old = atomic64_cmpxchg((v), c, c + (a)); | |
| if (likely(old == c)) | |
| break; | |
| c = old; | |
| } | |
| return c != (u); | |
| } | |
| #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) | |
| #define atomic64_dec_return(v) atomic64_sub_return(1, (v)) | |
| #define atomic64_inc_return(v) atomic64_add_return(1, (v)) | |
| /* | |
| * atomic64_sub_and_test - subtract value from variable and test result | |
| * @i: integer value to subtract | |
| * @v: pointer of type atomic64_t | |
| * | |
| * Atomically subtracts @i from @v and returns | |
| * true if the result is zero, or false for all | |
| * other cases. | |
| */ | |
| #define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0) | |
| /* | |
| * atomic64_inc_and_test - increment and test | |
| * @v: pointer of type atomic64_t | |
| * | |
| * Atomically increments @v by 1 | |
| * and returns true if the result is zero, or false for all | |
| * other cases. | |
| */ | |
| #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) | |
| /* | |
| * atomic64_dec_and_test - decrement by 1 and test | |
| * @v: pointer of type atomic64_t | |
| * | |
| * Atomically decrements @v by 1 and | |
| * returns true if the result is 0, or false for all other | |
| * cases. | |
| */ | |
| #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0) | |
| /* | |
| * atomic64_dec_if_positive - decrement by 1 if old value positive | |
| * @v: pointer of type atomic64_t | |
| */ | |
| #define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v) | |
| /* | |
| * atomic64_inc - increment atomic variable | |
| * @v: pointer of type atomic64_t | |
| * | |
| * Atomically increments @v by 1. | |
| */ | |
| #define atomic64_inc(v) atomic64_add(1, (v)) | |
| /* | |
| * atomic64_dec - decrement and test | |
| * @v: pointer of type atomic64_t | |
| * | |
| * Atomically decrements @v by 1. | |
| */ | |
| #define atomic64_dec(v) atomic64_sub(1, (v)) | |
| /* | |
| * atomic64_add_negative - add and test if negative | |
| * @v: pointer of type atomic64_t | |
| * @i: integer value to add | |
| * | |
| * Atomically adds @i to @v and returns true | |
| * if the result is negative, or false when | |
| * result is greater than or equal to zero. | |
| */ | |
| #define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0) | |
| #endif /* CONFIG_64BIT */ | |
| #endif /* _ASM_ATOMIC_H */ |