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    Subject[PATCH 6/24] make atomic_read() behave consistently on frv
    From: Chris Snook <csnook@redhat.com>

    Make atomic_read() volatile on frv. This ensures that busy-waiting
    for an interrupt handler to change an atomic_t won't get compiled to an
    infinite loop, consistent with SMP architectures.

    Signed-off-by: Chris Snook <csnook@redhat.com>

    --- linux-2.6.23-rc2-orig/include/asm-frv/atomic.h 2007-07-08 19:32:17.000000000 -0400
    +++ linux-2.6.23-rc2/include/asm-frv/atomic.h 2007-08-09 06:41:48.000000000 -0400
    @@ -40,7 +40,12 @@ typedef struct {
    } atomic_t;

    #define ATOMIC_INIT(i) { (i) }
    -#define atomic_read(v) ((v)->counter)
    +
    +/*
    + * Casting to volatile here minimizes the need for barriers,
    + * without having to declare the type itself as volatile.
    + */
    +#define atomic_read(v) (*(volatile int *)&(v)->counter)
    #define atomic_set(v, i) (((v)->counter) = (i))

    #ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
    -
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