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    Subject[tip:perfcounters/urgent] x86: atomic64: Code atomic(64)_read and atomic(64)_set in C not CPP
    Commit-ID:  8e049ef054f1cc765f05f13e1396bb9a17c19e66
    Gitweb: http://git.kernel.org/tip/8e049ef054f1cc765f05f13e1396bb9a17c19e66
    Author: Paul Mackerras <paulus@samba.org>
    AuthorDate: Thu, 2 Jul 2009 08:57:12 +1000
    Committer: Ingo Molnar <mingo@elte.hu>
    CommitDate: Fri, 3 Jul 2009 14:42:39 +0200

    x86: atomic64: Code atomic(64)_read and atomic(64)_set in C not CPP

    Occasionally we get bugs where atomic_read or atomic_set are
    used on atomic64_t variables or vice versa. These bugs don't
    generate warnings on x86 because atomic_read and atomic_set are
    coded as macros rather than C functions, so we don't get any
    type-checking on their arguments; similarly for atomic64_read
    and atomic64_set in 64-bit kernels.

    This converts them to C functions so that the arguments are
    type-checked and bugs like this will get caught more easily. It
    also converts atomic_cmpxchg and atomic_xchg, and
    atomic64_cmpxchg and atomic64_xchg on 64-bit, so we get
    type-checking on their arguments too.

    Compiling a typical 64-bit x86 config, this generates no new
    warnings, and the vmlinux text is 86 bytes smaller.

    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Mike Galbraith <efault@gmx.de>
    Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: David Howells <dhowells@redhat.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Arnd Bergmann <arnd@arndb.de>
    LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain>
    Signed-off-by: Ingo Molnar <mingo@elte.hu>


    ---
    arch/x86/include/asm/atomic_32.h | 16 +++++++++++--
    arch/x86/include/asm/atomic_64.h | 42 ++++++++++++++++++++++++++++++-------
    2 files changed, 47 insertions(+), 11 deletions(-)

    diff --git a/arch/x86/include/asm/atomic_32.h b/arch/x86/include/asm/atomic_32.h
    index b551bb1..aa045de 100644
    --- a/arch/x86/include/asm/atomic_32.h
    +++ b/arch/x86/include/asm/atomic_32.h
    @@ -31,7 +31,10 @@ static inline int atomic_read(const atomic_t *v)
    *
    * Atomically sets the value of @v to @i.
    */
    -#define atomic_set(v, i) (((v)->counter) = (i))
    +static inline void atomic_set(atomic_t *v, int i)
    +{
    + v->counter = i;
    +}

    /**
    * atomic_add - add integer to atomic variable
    @@ -203,8 +206,15 @@ static inline int atomic_sub_return(int i, atomic_t *v)
    return atomic_add_return(-i, v);
    }

    -#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
    -#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
    +static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
    +{
    + return cmpxchg(&v->counter, old, new);
    +}
    +
    +static inline int atomic_xchg(atomic_t *v, int new)
    +{
    + return xchg(&v->counter, new);
    +}

    /**
    * atomic_add_unless - add unless the number is already a given value
    diff --git a/arch/x86/include/asm/atomic_64.h b/arch/x86/include/asm/atomic_64.h
    index 0d63602..d605dc2 100644
    --- a/arch/x86/include/asm/atomic_64.h
    +++ b/arch/x86/include/asm/atomic_64.h
    @@ -18,7 +18,10 @@
    *
    * Atomically reads the value of @v.
    */
    -#define atomic_read(v) ((v)->counter)
    +static inline int atomic_read(const atomic_t *v)
    +{
    + return v->counter;
    +}

    /**
    * atomic_set - set atomic variable
    @@ -27,7 +30,10 @@
    *
    * Atomically sets the value of @v to @i.
    */
    -#define atomic_set(v, i) (((v)->counter) = (i))
    +static inline void atomic_set(atomic_t *v, int i)
    +{
    + v->counter = i;
    +}

    /**
    * atomic_add - add integer to atomic variable
    @@ -192,7 +198,10 @@ static inline int atomic_sub_return(int i, atomic_t *v)
    * Atomically reads the value of @v.
    * Doesn't imply a read memory barrier.
    */
    -#define atomic64_read(v) ((v)->counter)
    +static inline long atomic64_read(const atomic64_t *v)
    +{
    + return v->counter;
    +}

    /**
    * atomic64_set - set atomic64 variable
    @@ -201,7 +210,10 @@ static inline int atomic_sub_return(int i, atomic_t *v)
    *
    * Atomically sets the value of @v to @i.
    */
    -#define atomic64_set(v, i) (((v)->counter) = (i))
    +static inline void atomic64_set(atomic64_t *v, long i)
    +{
    + v->counter = i;
    +}

    /**
    * atomic64_add - add integer to atomic64 variable
    @@ -355,11 +367,25 @@ static inline long atomic64_sub_return(long i, atomic64_t *v)
    #define atomic64_inc_return(v) (atomic64_add_return(1, (v)))
    #define atomic64_dec_return(v) (atomic64_sub_return(1, (v)))

    -#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
    -#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
    +static inline long atomic64_cmpxchg(atomic64_t *v, long old, long new)
    +{
    + return cmpxchg(&v->counter, old, new);
    +}
    +
    +static inline long atomic64_xchg(atomic64_t *v, long new)
    +{
    + return xchg(&v->counter, new);
    +}

    -#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
    -#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
    +static inline long atomic_cmpxchg(atomic_t *v, int old, int new)
    +{
    + return cmpxchg(&v->counter, old, new);
    +}
    +
    +static inline long atomic_xchg(atomic_t *v, int new)
    +{
    + return xchg(&v->counter, new);
    +}

    /**
    * atomic_add_unless - add unless the number is a given value

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