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    Subject[patch 12/23] local_t m32r use architecture specific cmpxchg_local
    On m32r, use the new cmpxchg_local as primitive for the local_cmpxchg
    operation.

    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
    CC: takata@linux-m32r.org
    CC: linux-m32r@ml.linux-m32r.org
    ---
    include/asm-m32r/local.h | 362 ++++++++++++++++++++++++++++++++++++++++++++++-
    1 file changed, 361 insertions(+), 1 deletion(-)

    Index: linux-2.6-lttng/include/asm-m32r/local.h
    ===================================================================
    --- linux-2.6-lttng.orig/include/asm-m32r/local.h 2007-07-20 17:29:08.000000000 -0400
    +++ linux-2.6-lttng/include/asm-m32r/local.h 2007-07-20 17:43:28.000000000 -0400
    @@ -1,6 +1,366 @@
    #ifndef __M32R_LOCAL_H
    #define __M32R_LOCAL_H

    -#include <asm-generic/local.h>
    +/*
    + * linux/include/asm-m32r/local.h
    + *
    + * M32R version:
    + * Copyright (C) 2001, 2002 Hitoshi Yamamoto
    + * Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
    + * Copyright (C) 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
    + */
    +
    +#include <linux/percpu.h>
    +#include <asm/assembler.h>
    +#include <asm/system.h>
    +#include <asm/local.h>
    +
    +/*
    + * Atomic operations that C can't guarantee us. Useful for
    + * resource counting etc..
    + */
    +
    +/*
    + * Make sure gcc doesn't try to be clever and move things around
    + * on us. We need to use _exactly_ the address the user gave us,
    + * not some alias that contains the same information.
    + */
    +typedef struct { volatile int counter; } local_t;
    +
    +#define LOCAL_INIT(i) { (i) }
    +
    +/**
    + * local_read - read local variable
    + * @l: pointer of type local_t
    + *
    + * Atomically reads the value of @l.
    + */
    +#define local_read(l) ((l)->counter)
    +
    +/**
    + * local_set - set local variable
    + * @l: pointer of type local_t
    + * @i: required value
    + *
    + * Atomically sets the value of @l to @i.
    + */
    +#define local_set(l,i) (((l)->counter) = (i))
    +
    +/**
    + * local_add_return - add long to local variable and return it
    + * @i: long value to add
    + * @l: pointer of type local_t
    + *
    + * Atomically adds @i to @l and return (@i + @l).
    + */
    +static __inline__ long local_add_return(long i, local_t *l)
    +{
    + unsigned long flags;
    + long result;
    +
    + local_irq_save(flags);
    + __asm__ __volatile__ (
    + "# local_add_return \n\t"
    + DCACHE_CLEAR("%0", "r4", "%1")
    + "ld %0, @%1; \n\t"
    + "add %0, %2; \n\t"
    + "st %0, @%1; \n\t"
    + : "=&r" (result)
    + : "r" (&l->counter), "r" (i)
    + : "memory"
    +#ifdef CONFIG_CHIP_M32700_TS1
    + , "r4"
    +#endif /* CONFIG_CHIP_M32700_TS1 */
    + );
    + local_irq_restore(flags);
    +
    + return result;
    +}
    +
    +/**
    + * local_sub_return - subtract long from local variable and return it
    + * @i: long value to subtract
    + * @l: pointer of type local_t
    + *
    + * Atomically subtracts @i from @l and return (@l - @i).
    + */
    +static __inline__ long local_sub_return(long i, local_t *l)
    +{
    + unsigned long flags;
    + long result;
    +
    + local_irq_save(flags);
    + __asm__ __volatile__ (
    + "# local_sub_return \n\t"
    + DCACHE_CLEAR("%0", "r4", "%1")
    + "ld %0, @%1; \n\t"
    + "sub %0, %2; \n\t"
    + "st %0, @%1; \n\t"
    + : "=&r" (result)
    + : "r" (&l->counter), "r" (i)
    + : "memory"
    +#ifdef CONFIG_CHIP_M32700_TS1
    + , "r4"
    +#endif /* CONFIG_CHIP_M32700_TS1 */
    + );
    + local_irq_restore(flags);
    +
    + return result;
    +}
    +
    +/**
    + * local_add - add long to local variable
    + * @i: long value to add
    + * @l: pointer of type local_t
    + *
    + * Atomically adds @i to @l.
    + */
    +#define local_add(i,l) ((void) local_add_return((i), (l)))
    +
    +/**
    + * local_sub - subtract the local variable
    + * @i: long value to subtract
    + * @l: pointer of type local_t
    + *
    + * Atomically subtracts @i from @l.
    + */
    +#define local_sub(i,l) ((void) local_sub_return((i), (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_return - increment local variable and return it
    + * @l: pointer of type local_t
    + *
    + * Atomically increments @l by 1 and returns the result.
    + */
    +static __inline__ long local_inc_return(local_t *l)
    +{
    + unsigned long flags;
    + long result;
    +
    + local_irq_save(flags);
    + __asm__ __volatile__ (
    + "# local_inc_return \n\t"
    + DCACHE_CLEAR("%0", "r4", "%1")
    + "ld %0, @%1; \n\t"
    + "addi %0, #1; \n\t"
    + "st %0, @%1; \n\t"
    + : "=&r" (result)
    + : "r" (&l->counter)
    + : "memory"
    +#ifdef CONFIG_CHIP_M32700_TS1
    + , "r4"
    +#endif /* CONFIG_CHIP_M32700_TS1 */
    + );
    + local_irq_restore(flags);
    +
    + return result;
    +}
    +
    +/**
    + * local_dec_return - decrement local variable and return it
    + * @l: pointer of type local_t
    + *
    + * Atomically decrements @l by 1 and returns the result.
    + */
    +static __inline__ long local_dec_return(local_t *l)
    +{
    + unsigned long flags;
    + long result;
    +
    + local_irq_save(flags);
    + __asm__ __volatile__ (
    + "# local_dec_return \n\t"
    + DCACHE_CLEAR("%0", "r4", "%1")
    + "ld %0, @%1; \n\t"
    + "addi %0, #-1; \n\t"
    + "st %0, @%1; \n\t"
    + : "=&r" (result)
    + : "r" (&l->counter)
    + : "memory"
    +#ifdef CONFIG_CHIP_M32700_TS1
    + , "r4"
    +#endif /* CONFIG_CHIP_M32700_TS1 */
    + );
    + local_irq_restore(flags);
    +
    + return result;
    +}
    +
    +/**
    + * local_inc - increment local variable
    + * @l: pointer of type local_t
    + *
    + * Atomically increments @l by 1.
    + */
    +#define local_inc(l) ((void)local_inc_return(l))
    +
    +/**
    + * local_dec - decrement local variable
    + * @l: pointer of type local_t
    + *
    + * Atomically decrements @l by 1.
    + */
    +#define local_dec(l) ((void)local_dec_return(l))
    +
    +/**
    + * 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 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_dec_return(l) == 0)
    +
    +/**
    + * 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)
    +
    +#define local_cmpxchg(l, o, n) (cmpxchg_local(&((l)->counter), (o), (n)))
    +#define local_xchg(v, new) (xchg_local(&((l)->counter), new))
    +
    +/**
    + * 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.
    + */
    +static __inline__ int local_add_unless(local_t *l, long a, long u)
    +{
    + long c, old;
    + c = local_read(l);
    + for (;;) {
    + if (unlikely(c == (u)))
    + break;
    + old = local_cmpxchg((l), c, c + (a));
    + if (likely(old == c))
    + break;
    + c = old;
    + }
    + return c != (u);
    +}
    +
    +#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
    +
    +static __inline__ void local_clear_mask(unsigned long mask, local_t *addr)
    +{
    + unsigned long flags;
    + unsigned long tmp;
    +
    + local_irq_save(flags);
    + __asm__ __volatile__ (
    + "# local_clear_mask \n\t"
    + DCACHE_CLEAR("%0", "r5", "%1")
    + "ld %0, @%1; \n\t"
    + "and %0, %2; \n\t"
    + "st %0, @%1; \n\t"
    + : "=&r" (tmp)
    + : "r" (addr), "r" (~mask)
    + : "memory"
    +#ifdef CONFIG_CHIP_M32700_TS1
    + , "r5"
    +#endif /* CONFIG_CHIP_M32700_TS1 */
    + );
    + local_irq_restore(flags);
    +}
    +
    +static __inline__ void local_set_mask(unsigned long mask, local_t *addr)
    +{
    + unsigned long flags;
    + unsigned long tmp;
    +
    + local_irq_save(flags);
    + __asm__ __volatile__ (
    + "# local_set_mask \n\t"
    + DCACHE_CLEAR("%0", "r5", "%1")
    + "ld %0, @%1; \n\t"
    + "or %0, %2; \n\t"
    + "st %0, @%1; \n\t"
    + : "=&r" (tmp)
    + : "r" (addr), "r" (mask)
    + : "memory"
    +#ifdef CONFIG_CHIP_M32700_TS1
    + , "r5"
    +#endif /* CONFIG_CHIP_M32700_TS1 */
    + );
    + local_irq_restore(flags);
    +}
    +
    +/* Atomic operations are already serializing on m32r */
    +#define smp_mb__before_local_dec() barrier()
    +#define smp_mb__after_local_dec() barrier()
    +#define smp_mb__before_local_inc() barrier()
    +#define smp_mb__after_local_inc() barrier()
    +
    +/* 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 __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))
    +
    +/* 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.
    + */
    +
    +/* Need to disable preemption for the cpu local counters otherwise we could
    + still access a variable of a previous CPU in a non local 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(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 /* __M32R_LOCAL_H */
    --
    Mathieu Desnoyers
    Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
    OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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