Generic Mutex Subsystem, add-atomic-call-func-i386.patch
PATCH 3/15 Generic Mutex Subsystem, add-atomic-call-func-i386.patch
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 <[email protected]>
----
include/asm-i386/atomic.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 57 insertions(+)
include/asm-i386/atomic.h +57 -0
@@ -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" \