void
ast_taken(void)
{
thread_t self = current_thread();
ast_t reasons;
/*
* Interrupts are still disabled.
* We must clear need_ast and then enable interrupts.
*/
reasons = need_ast[cpu_number()];
need_ast[cpu_number()] = AST_ZILCH;
(void) spl0();
/*
* These actions must not block.
*/
if (reasons & AST_NETWORK)
net_ast();
/*
* Make darn sure that we don't call thread_halt_self
* or thread_block from the idle thread.
*/
if (self != current_processor()->idle_thread) {
#ifndef MIGRATING_THREADS
while (thread_should_halt(self))
thread_halt_self();
#endif
/*
* One of the previous actions might well have
* woken a high-priority thread, so we use
* csw_needed in addition to AST_BLOCK.
*/
if ((reasons & AST_BLOCK) ||
csw_needed(self, current_processor())) {
counter(c_ast_taken_block++);
thread_block(thread_exception_return);
}
}
}
/*
* Called at splsched.
*/
void
ast_taken(
ast_t reasons,
boolean_t enable
)
{
register thread_t self = current_thread();
register int mycpu = cpu_number();
boolean_t preempt_trap = (reasons == AST_PREEMPTION);
reasons &= need_ast[mycpu];
need_ast[mycpu] &= ~reasons;
/*
* Handle ASTs for all threads
* except idle processor threads.
*/
if (!(self->state & TH_IDLE)) {
/*
* Check for urgent preemption.
*/
if ( (reasons & AST_URGENT) &&
wait_queue_assert_possible(self) ) {
if (reasons & AST_PREEMPT) {
counter(c_ast_taken_block++);
thread_block_reason(THREAD_CONTINUE_NULL,
AST_PREEMPT | AST_URGENT);
}
reasons &= ~AST_PREEMPTION;
}
/*
* The kernel preempt traps
* skip all other ASTs.
*/
if (!preempt_trap) {
ml_set_interrupts_enabled(enable);
#ifdef MACH_BSD
/*
* Handle BSD hook.
*/
if (reasons & AST_BSD) {
extern void bsd_ast(thread_act_t act);
thread_act_t act = self->top_act;
thread_ast_clear(act, AST_BSD);
bsd_ast(act);
}
#endif
/*
* Thread APC hook.
*/
if (reasons & AST_APC)
act_execute_returnhandlers();
ml_set_interrupts_enabled(FALSE);
/*
* Check for preemption.
*/
if (reasons & AST_PREEMPT) {
processor_t myprocessor = current_processor();
if (csw_needed(self, myprocessor))
reasons = AST_PREEMPT;
else
reasons = AST_NONE;
}
if ( (reasons & AST_PREEMPT) &&
wait_queue_assert_possible(self) ) {
counter(c_ast_taken_block++);
thread_block_reason(thread_exception_return, AST_PREEMPT);
}
}
}
ml_set_interrupts_enabled(enable);
}
void
ast_check(void)
{
register int mycpu;
register processor_t myprocessor;
register thread_t thread = current_thread();
spl_t s = splsched();
mp_disable_preemption();
mycpu = cpu_number();
/*
* Check processor state for ast conditions.
*/
myprocessor = cpu_to_processor(mycpu);
switch(myprocessor->state) {
case PROCESSOR_OFF_LINE:
case PROCESSOR_IDLE:
case PROCESSOR_DISPATCHING:
/*
* No ast.
*/
break;
#if NCPUS > 1
case PROCESSOR_ASSIGN:
case PROCESSOR_SHUTDOWN:
/*
* Need ast to force action thread onto processor.
*
* XXX Should check if action thread is already there.
*/
ast_on(mycpu, AST_BLOCK);
break;
#endif /* NCPUS > 1 */
case PROCESSOR_RUNNING:
case PROCESSOR_VIDLE:
/*
* Propagate thread ast to processor. If we already
* need an ast, don't look for more reasons.
*/
ast_propagate(current_act(), mycpu);
if (ast_needed(mycpu))
break;
/*
* Context switch check.
*/
if (csw_needed(thread, myprocessor)) {
ast_on(mycpu, (myprocessor->first_quantum ?
AST_BLOCK : AST_QUANTUM));
}
break;
default:
panic("ast_check: Bad processor state");
}
mp_enable_preemption();
splx(s);
}
void
ast_taken(
boolean_t preemption,
ast_t mask,
spl_t old_spl
#if FAST_IDLE
,int thread_type
#endif /* FAST_IDLE */
)
{
register thread_t self = current_thread();
register processor_t mypr;
register ast_t reasons;
register int mycpu;
thread_act_t act = self->top_act;
/*
* Interrupts are still disabled.
* We must clear need_ast and then enable interrupts.
*/
extern void log_thread_action(thread_t, char *);
#if 0
log_thread_action (current_thread(), "ast_taken");
#endif
mp_disable_preemption();
mycpu = cpu_number();
reasons = need_ast[mycpu] & mask;
need_ast[mycpu] &= ~reasons;
mp_enable_preemption();
splx(old_spl);
/*
* These actions must not block.
*/
#if MCMSG
if (reasons & AST_MCMSG)
mcmsg_ast();
#endif /* MCMSG */
if (reasons & AST_NETWORK)
net_ast();
#if MCMSG_ENG
if (reasons & AST_RPCREQ)
rpc_engine_request_intr();
if (reasons & AST_RPCREPLY)
rpc_engine_reply_intr();
if (reasons & AST_RPCDEPART)
rpc_engine_depart_intr();
if (reasons & AST_RDMASEND)
rdma_engine_send_intr();
if (reasons & AST_RDMARECV)
rdma_engine_recv_intr();
if (reasons & AST_RDMATXF)
rdma_engine_send_fault_intr();
if (reasons & AST_RDMARXF)
rdma_engine_recv_fault_intr();
#endif /* MCMSG_ENG */
#if PARAGON860 && MCMSG_ENG
if (reasons & AST_SCAN_INPUT)
scan_input_ast();
#endif /* PARAGON860 */
#if DIPC
if (reasons & AST_DIPC)
dipc_ast();
#endif /* DIPC */
/*
* Make darn sure that we don't call thread_halt_self
* or thread_block from the idle thread.
*/
/* XXX - this isn't currently right for the HALT case... */
mp_disable_preemption();
mypr = current_processor();
if (self == mypr->idle_thread) {
#if NCPUS == 1
if (reasons & AST_URGENT) {
if (!preemption)
panic("ast_taken: AST_URGENT for idle_thr w/o preemption");
}
#endif
mp_enable_preemption();
return;
}
mp_enable_preemption();
#if FAST_IDLE
if (thread_type != NO_IDLE_THREAD)
return;
#endif /* FAST_IDLE */
#if TASK_SWAPPER
/* must be before AST_APC */
if (reasons & AST_SWAPOUT) {
spl_t s;
swapout_ast();
s = splsched();
mp_disable_preemption();
mycpu = cpu_number();
if (need_ast[mycpu] & AST_APC) {
/* generated in swapout_ast() to get suspended */
reasons |= AST_APC; /* process now ... */
need_ast[mycpu] &= ~AST_APC; /* ... and not later */
}
mp_enable_preemption();
splx(s);
}
#endif /* TASK_SWAPPER */
/* migration APC hook */
if (reasons & AST_APC) {
act_execute_returnhandlers();
return; /* auto-retry will catch anything new */
}
/*
* thread_block needs to know if the thread's quantum
* expired so the thread can be put on the tail of
* run queue. One of the previous actions might well
* have woken a high-priority thread, so we also use
* csw_needed check.
*/
{ void (*safept)(void) = (void (*)(void))SAFE_EXCEPTION_RETURN;
if (reasons &= AST_PREEMPT) {
if (preemption)
safept = (void (*)(void)) 0;
} else {
mp_disable_preemption();
mypr = current_processor();
if (csw_needed(self, mypr)) {
reasons = (mypr->first_quantum
? AST_BLOCK
: AST_QUANTUM);
}
mp_enable_preemption();
}
if (reasons) {
counter(c_ast_taken_block++);
thread_block_reason(safept, reasons);
}
}
}
void
ast_check(void)
{
int mycpu = cpu_number();
processor_t myprocessor;
thread_t thread = current_thread();
run_queue_t rq;
spl_t s = splsched();
/*
* Check processor state for ast conditions.
*/
myprocessor = cpu_to_processor(mycpu);
switch(myprocessor->state) {
case PROCESSOR_OFF_LINE:
case PROCESSOR_IDLE:
case PROCESSOR_DISPATCHING:
/*
* No ast.
*/
break;
#if NCPUS > 1
case PROCESSOR_ASSIGN:
case PROCESSOR_SHUTDOWN:
/*
* Need ast to force action thread onto processor.
*
* XXX Should check if action thread is already there.
*/
ast_on(mycpu, AST_BLOCK);
break;
#endif /* NCPUS > 1 */
case PROCESSOR_RUNNING:
/*
* Propagate thread ast to processor. If we already
* need an ast, don't look for more reasons.
*/
ast_propagate(thread, mycpu);
if (ast_needed(mycpu))
break;
/*
* Context switch check. The csw_needed macro isn't
* used here because the rq->low hint may be wrong,
* and fixing it here avoids an extra ast.
* First check the easy cases.
*/
if (thread->state & TH_SUSP || myprocessor->runq.count > 0) {
ast_on(mycpu, AST_BLOCK);
break;
}
/*
* Update lazy evaluated runq->low if only timesharing.
*/
#if MACH_FIXPRI
if (myprocessor->processor_set->policies & POLICY_FIXEDPRI) {
if (csw_needed(thread,myprocessor)) {
ast_on(mycpu, AST_BLOCK);
break;
}
else {
/*
* For fixed priority threads, set first_quantum
* so entire new quantum is used.
*/
if (thread->policy == POLICY_FIXEDPRI)
myprocessor->first_quantum = TRUE;
}
}
else {
#endif /* MACH_FIXPRI */
rq = &(myprocessor->processor_set->runq);
if (!(myprocessor->first_quantum) && (rq->count > 0)) {
queue_t q;
/*
* This is not the first quantum, and there may
* be something in the processor_set runq.
* Check whether low hint is accurate.
*/
q = rq->runq + *(volatile int *)&rq->low;
if (queue_empty(q)) {
int i;
/*
* Need to recheck and possibly update hint.
*/
simple_lock(&rq->lock);
q = rq->runq + rq->low;
if (rq->count > 0) {
for (i = rq->low; i < NRQS; i++) {
if(!(queue_empty(q)))
break;
q++;
}
rq->low = i;
}
simple_unlock(&rq->lock);
}
if (rq->low <= thread->sched_pri) {
ast_on(mycpu, AST_BLOCK);
break;
}
}
#if MACH_FIXPRI
}
#endif /* MACH_FIXPRI */
break;
default:
panic("ast_check: Bad processor state (cpu %d processor %08x) state: %d",
mycpu, myprocessor, myprocessor->state);
}
(void) splx(s);
}
