--- /dev/null
+/*
+ * 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) ACCESS_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) ((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)
+
+#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) ACCESS_ONCE((v)->counter)
+
+/*
+ * atomic64_set - set atomic variable
+ * @v: pointer of type atomic64_t
+ * @i: required value
+ */
+#define atomic64_set(v, i) ((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)
+
+#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 the old value of @v.
+ */
+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 */
Code Review / kvmfornfv.git / blobdiff