*/
static bool irq_work_claim(struct irq_work *work)
{
- int flags, oflags, nflags;
+ int oflags;
+ oflags = atomic_fetch_or(IRQ_WORK_CLAIMED, &work->flags);
/*
- * Start with our best wish as a premise but only trust any
- * flag value after cmpxchg() result.
+ * If the work is already pending, no need to raise the IPI.
+ * The pairing atomic_xchg() in irq_work_run() makes sure
+ * everything we did before is visible.
*/
- flags = atomic_read(&work->flags) & ~IRQ_WORK_PENDING;
- for (;;) {
- nflags = flags | IRQ_WORK_CLAIMED;
- oflags = atomic_cmpxchg(&work->flags, flags, nflags);
- if (oflags == flags)
- break;
- if (oflags & IRQ_WORK_PENDING)
- return false;
- flags = oflags;
- cpu_relax();
- }
-
+ if (oflags & IRQ_WORK_PENDING)
+ return false;
return true;
}