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local_t: mips extension
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Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mathieu Desnoyers authored and Linus Torvalds committed May 8, 2007
1 parent 4431f46 commit 7232311
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304 changes: 266 additions & 38 deletions include/asm-mips/local.h
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#ifndef _ASM_LOCAL_H
#define _ASM_LOCAL_H
#ifndef _ARCH_MIPS_LOCAL_H
#define _ARCH_MIPS_LOCAL_H

#include <linux/percpu.h>
#include <linux/bitops.h>
#include <asm/atomic.h>
#include <asm/war.h>

#ifdef CONFIG_32BIT
typedef struct
{
atomic_long_t a;
} local_t;

typedef atomic_t local_t;
#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) }

#define LOCAL_INIT(i) ATOMIC_INIT(i)
#define local_read(v) atomic_read(v)
#define local_set(v,i) atomic_set(v,i)
#define local_read(l) atomic_long_read(&(l)->a)
#define local_set(l,i) atomic_long_set(&(l)->a, (i))

#define local_inc(v) atomic_inc(v)
#define local_dec(v) atomic_dec(v)
#define local_add(i, v) atomic_add(i, v)
#define local_sub(i, v) atomic_sub(i, v)
#define local_add(i,l) atomic_long_add((i),(&(l)->a))
#define local_sub(i,l) atomic_long_sub((i),(&(l)->a))
#define local_inc(l) atomic_long_inc(&(l)->a)
#define local_dec(l) atomic_long_dec(&(l)->a)

#endif
/*
* Same as above, but return the result value
*/
static __inline__ long local_add_return(long i, local_t * l)
{
unsigned long result;

if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;

__asm__ __volatile__(
" .set mips3 \n"
"1:" __LL "%1, %2 # local_add_return \n"
" addu %0, %1, %3 \n"
__SC "%0, %2 \n"
" beqzl %0, 1b \n"
" addu %0, %1, %3 \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;

__asm__ __volatile__(
" .set mips3 \n"
"1:" __LL "%1, %2 # local_add_return \n"
" addu %0, %1, %3 \n"
__SC "%0, %2 \n"
" beqz %0, 1b \n"
" addu %0, %1, %3 \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
} else {
unsigned long flags;

#ifdef CONFIG_64BIT
local_irq_save(flags);
result = l->a.counter;
result += i;
l->a.counter = result;
local_irq_restore(flags);
}

typedef atomic64_t local_t;
return result;
}

#define LOCAL_INIT(i) ATOMIC64_INIT(i)
#define local_read(v) atomic64_read(v)
#define local_set(v,i) atomic64_set(v,i)
static __inline__ long local_sub_return(long i, local_t * l)
{
unsigned long result;

#define local_inc(v) atomic64_inc(v)
#define local_dec(v) atomic64_dec(v)
#define local_add(i, v) atomic64_add(i, v)
#define local_sub(i, v) atomic64_sub(i, v)
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;

#endif
__asm__ __volatile__(
" .set mips3 \n"
"1:" __LL "%1, %2 # local_sub_return \n"
" subu %0, %1, %3 \n"
__SC "%0, %2 \n"
" beqzl %0, 1b \n"
" subu %0, %1, %3 \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;

#define __local_inc(v) ((v)->counter++)
#define __local_dec(v) ((v)->counter--)
#define __local_add(i,v) ((v)->counter+=(i))
#define __local_sub(i,v) ((v)->counter-=(i))
__asm__ __volatile__(
" .set mips3 \n"
"1:" __LL "%1, %2 # local_sub_return \n"
" subu %0, %1, %3 \n"
__SC "%0, %2 \n"
" beqz %0, 1b \n"
" subu %0, %1, %3 \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
} else {
unsigned long flags;

local_irq_save(flags);
result = l->a.counter;
result -= i;
l->a.counter = result;
local_irq_restore(flags);
}

return result;
}

/*
* Use these for per-cpu local_t variables: on some archs they are
* local_sub_if_positive - conditionally subtract integer from atomic variable
* @i: integer value to subtract
* @l: pointer of type local_t
*
* Atomically test @l and subtract @i if @l is greater or equal than @i.
* The function returns the old value of @l minus @i.
*/
static __inline__ long local_sub_if_positive(long i, local_t * l)
{
unsigned long result;

if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long temp;

__asm__ __volatile__(
" .set mips3 \n"
"1:" __LL "%1, %2 # local_sub_if_positive\n"
" dsubu %0, %1, %3 \n"
" bltz %0, 1f \n"
__SC "%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), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
} else if (cpu_has_llsc) {
unsigned long temp;

__asm__ __volatile__(
" .set mips3 \n"
"1:" __LL "%1, %2 # local_sub_if_positive\n"
" dsubu %0, %1, %3 \n"
" bltz %0, 1f \n"
__SC "%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), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
} else {
unsigned long flags;

local_irq_save(flags);
result = l->a.counter;
result -= i;
if (result >= 0)
l->a.counter = result;
local_irq_restore(flags);
}

return result;
}

#define local_cmpxchg(l, o, n) \
((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
#define local_xchg(l, n) (xchg_local(&((l)->a.counter),(n)))

/**
* local_add_unless - add unless the number is a given value
* @l: pointer of type local_t
* @a: the amount to add to l...
* @u: ...unless l is equal to u.
*
* Atomically adds @a to @l, so long as it was not @u.
* Returns non-zero if @l was not @u, and zero otherwise.
*/
#define local_add_unless(l, a, u) \
({ \
long c, old; \
c = local_read(l); \
while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
c = old; \
c != (u); \
})
#define local_inc_not_zero(l) local_add_unless((l), 1, 0)

#define local_dec_return(l) local_sub_return(1,(l))
#define local_inc_return(l) local_add_return(1,(l))

/*
* local_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @l: pointer of type local_t
*
* Atomically subtracts @i from @l and returns
* true if the result is zero, or false for all
* other cases.
*/
#define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)

/*
* local_inc_and_test - increment and test
* @l: pointer of type local_t
*
* Atomically increments @l by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define local_inc_and_test(l) (local_inc_return(l) == 0)

/*
* local_dec_and_test - decrement by 1 and test
* @l: pointer of type local_t
*
* Atomically decrements @l by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)

/*
* local_dec_if_positive - decrement by 1 if old value positive
* @l: pointer of type local_t
*/
#define local_dec_if_positive(l) local_sub_if_positive(1, l)

/*
* local_add_negative - add and test if negative
* @l: pointer of type local_t
* @i: integer value to add
*
* Atomically adds @i to @l and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
#define local_add_negative(i,l) (local_add_return(i, (l)) < 0)

/* Use these for per-cpu local_t variables: on some archs they are
* much more efficient than these naive implementations. Note they take
* a variable, not an address.
*/
#define cpu_local_read(v) local_read(&__get_cpu_var(v))
#define cpu_local_set(v, i) local_set(&__get_cpu_var(v), (i))

#define cpu_local_inc(v) local_inc(&__get_cpu_var(v))
#define cpu_local_dec(v) local_dec(&__get_cpu_var(v))
#define cpu_local_add(i, v) local_add((i), &__get_cpu_var(v))
#define cpu_local_sub(i, v) local_sub((i), &__get_cpu_var(v))
#define __local_inc(l) ((l)->a.counter++)
#define __local_dec(l) ((l)->a.counter++)
#define __local_add(i,l) ((l)->a.counter+=(i))
#define __local_sub(i,l) ((l)->a.counter-=(i))

/* Need to disable preemption for the cpu local counters otherwise we could
still access a variable of a previous CPU in a non atomic way. */
#define cpu_local_wrap_v(l) \
({ local_t res__; \
preempt_disable(); \
res__ = (l); \
preempt_enable(); \
res__; })
#define cpu_local_wrap(l) \
({ preempt_disable(); \
l; \
preempt_enable(); }) \

#define cpu_local_read(l) cpu_local_wrap_v(local_read(&__get_cpu_var(l)))
#define cpu_local_set(l, i) cpu_local_wrap(local_set(&__get_cpu_var(l), (i)))
#define cpu_local_inc(l) cpu_local_wrap(local_inc(&__get_cpu_var(l)))
#define cpu_local_dec(l) cpu_local_wrap(local_dec(&__get_cpu_var(l)))
#define cpu_local_add(i, l) cpu_local_wrap(local_add((i), &__get_cpu_var(l)))
#define cpu_local_sub(i, l) cpu_local_wrap(local_sub((i), &__get_cpu_var(l)))

#define __cpu_local_inc(v) __local_inc(&__get_cpu_var(v))
#define __cpu_local_dec(v) __local_dec(&__get_cpu_var(v))
#define __cpu_local_add(i, v) __local_add((i), &__get_cpu_var(v))
#define __cpu_local_sub(i, v) __local_sub((i), &__get_cpu_var(v))
#define __cpu_local_inc(l) cpu_local_inc(l)
#define __cpu_local_dec(l) cpu_local_dec(l)
#define __cpu_local_add(i, l) cpu_local_add((i), (l))
#define __cpu_local_sub(i, l) cpu_local_sub((i), (l))

#endif /* _ASM_LOCAL_H */
#endif /* _ARCH_MIPS_LOCAL_H */

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