| /* |
| * 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(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_" #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); \ |
| } \ |
| \ |
| smp_llsc_mb(); \ |
| \ |
| 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_OPS(add, +=, addu) |
| ATOMIC_OPS(sub, -=, subu) |
| |
| ATOMIC_OP(and, &=, and) |
| ATOMIC_OP(or, |=, or) |
| ATOMIC_OP(xor, ^=, xor) |
| |
| #undef ATOMIC_OPS |
| #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(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_" #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); \ |
| } \ |
| \ |
| smp_llsc_mb(); \ |
| \ |
| 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_OPS(add, +=, daddu) |
| ATOMIC64_OPS(sub, -=, dsubu) |
| ATOMIC64_OP(and, &=, and) |
| ATOMIC64_OP(or, |=, or) |
| ATOMIC64_OP(xor, ^=, xor) |
| |
| #undef ATOMIC64_OPS |
| #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 */ |
