mirror of
https://sourceware.org/git/glibc.git
synced 2025-04-20 12:27:47 +03:00
32 lines
1.2 KiB
Plaintext
32 lines
1.2 KiB
Plaintext
/*
|
|
* @(#)sparc.gcc 10.1 (Sleepycat) 4/12/97
|
|
*
|
|
* The ldstub instruction takes the location specified by its first argument
|
|
* (a register containing a memory address) and loads its contents into its
|
|
* second argument (a register) and atomically sets the contents the location
|
|
* specified by its first argument to a byte of 1s. (The value in the second
|
|
* argument is never read, but only overwritten.)
|
|
*
|
|
* The membar instructions are needed to ensure that writes to the lock are
|
|
* correctly ordered with writes that occur later in the instruction stream.
|
|
*
|
|
* For gcc/sparc, 0 is clear, 1 is set.
|
|
*/
|
|
|
|
/* The stbar is needed for v8, and is implemented as membar #sync on v9,
|
|
so is functional there as well. For v7, stbar may generate an illegal
|
|
instruction and we have no way to tell what we're running on. Some
|
|
operating systems notice and skip this instruction in the fault handler. */
|
|
|
|
#define TSL_SET(tsl) ({ \
|
|
register tsl_t *__l = (tsl); \
|
|
register tsl_t __r; \
|
|
__asm__ volatile \
|
|
("ldstub [%1],%0; stbar" \
|
|
: "=r"( __r) : "r" (__l)); \
|
|
!__r; \
|
|
})
|
|
|
|
#define TSL_UNSET(tsl) (*(tsl) = 0)
|
|
#define TSL_INIT(tsl) TSL_UNSET(tsl)
|