Messages in this thread Patch in this message | | | Date | Mon, 19 Dec 2005 02:34:55 +0100 | From | Ingo Molnar <> | Subject | [patch 03/15] Generic Mutex Subsystem, add-atomic-call-func-i386.patch |
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add two new atomic ops to i386: atomic_dec_call_if_negative() and atomic_inc_call_if_nonpositive(), which are conditional-call-if atomic operations. Needed by the new mutex code.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
----
include/asm-i386/atomic.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 57 insertions(+)
Index: linux/include/asm-i386/atomic.h =================================================================== --- linux.orig/include/asm-i386/atomic.h +++ linux/include/asm-i386/atomic.h @@ -240,6 +240,63 @@ static __inline__ int atomic_sub_return( #define atomic_inc_return(v) (atomic_add_return(1,v)) #define atomic_dec_return(v) (atomic_sub_return(1,v)) +/** + * atomic_dec_call_if_negative - decrement and call function if negative + * @v: pointer of type atomic_t + * @fn: function to call if the result is negative + * + * Atomically decrements @v and calls a function if the result is negative. + * NOTE: the function is type-checked and must be a fastcall. + */ +#define atomic_dec_call_if_negative(v, fn_name) \ +do { \ + fastcall void (*__tmp)(atomic_t *) = fn_name; \ + \ + (void)__tmp; \ + typecheck(atomic_t *, v); \ + \ + __asm__ __volatile__( \ + LOCK "decl (%%eax)\n" \ + "js 2f\n" \ + "1:\n" \ + LOCK_SECTION_START("") \ + "2: call "#fn_name"\n\t" \ + "jmp 1b\n" \ + LOCK_SECTION_END \ + : \ + :"a" (v) \ + :"memory","cx","dx"); \ +} while (0) + +/** + * atomic_inc_call_if_nonpositive - increment and call function if nonpositive + * @v: pointer of type atomic_t + * @fn: function to call if the result is nonpositive + * + * Atomically increments @v and calls a function if the result is nonpositive. + * NOTE: the function is type-checked and must be a fastcall. + */ +#define atomic_inc_call_if_nonpositive(v, fn_name) \ +do { \ + fastcall void (*__tmp)(atomic_t *) = fn_name; \ + \ + (void)__tmp; \ + typecheck(atomic_t *, v); \ + \ + __asm__ __volatile__( \ + LOCK "incl (%%eax)\n" \ + "jle 2f\n" \ + "1:\n" \ + LOCK_SECTION_START("") \ + "2: call "#fn_name"\n\t" \ + "jmp 1b\n" \ + LOCK_SECTION_END \ + : \ + :"a" (v) \ + :"memory","cx","dx"); \ +} while (0) + + /* These are x86-specific, used by some header files */ #define atomic_clear_mask(mask, addr) \ __asm__ __volatile__(LOCK "andl %0,%1" \ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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