X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/1c79356b52d46aa6b508fb032f5ae709b1f2897b..a3d08fcd5120d2aa8303b6349ca8b14e3f284af3:/osfmk/kern/ast.c?ds=sidebyside

diff --git a/osfmk/kern/ast.c b/osfmk/kern/ast.c
index f454fe9a3..7540375ce 100644
--- a/osfmk/kern/ast.c
+++ b/osfmk/kern/ast.c
@@ -62,14 +62,12 @@
 #include <cputypes.h>
 #include <cpus.h>
 #include <platforms.h>
-#include <task_swapper.h>
 
 #include <kern/ast.h>
 #include <kern/counters.h>
 #include <kern/cpu_number.h>
 #include <kern/misc_protos.h>
 #include <kern/queue.h>
-#include <kern/sched.h>
 #include <kern/sched_prim.h>
 #include <kern/thread.h>
 #include <kern/thread_act.h>
@@ -77,9 +75,6 @@
 #include <kern/processor.h>
 #include <kern/spl.h>
 #include <mach/policy.h>
-#if	TASK_SWAPPER
-#include <kern/task_swap.h>
-#endif	/* TASK_SWAPPER */
 
 volatile ast_t need_ast[NCPUS];
 
@@ -95,207 +90,122 @@ ast_init(void)
 #endif	/* MACHINE_AST */
 }
 
+/*
+ * Called at splsched.
+ */
 void
 ast_taken(
-	boolean_t		preemption,
-	ast_t			mask,
-	boolean_t		interrupt
+	ast_t			reasons,
+	boolean_t		enable
 )
 {
-	register thread_t	self = current_thread();
-	register processor_t	mypr;
-	register ast_t		reasons;
-	register int		mycpu;
-	thread_act_t		act = self->top_act;
-#ifdef	MACH_BSD
-	extern void		bsd_ast(thread_act_t);
-	extern void		bsdinit_task(void);
-#endif
+	register thread_t		self = current_thread();
+	register int			mycpu = cpu_number();
+	boolean_t				preempt_trap = (reasons == AST_PREEMPTION);
 
-	mp_disable_preemption();
-	mycpu = cpu_number();
-	reasons = need_ast[mycpu] & mask;
+	reasons &= need_ast[mycpu];
 	need_ast[mycpu] &= ~reasons;
-	mp_enable_preemption();
-
-	ml_set_interrupts_enabled(interrupt);
 
 	/*
-	 * No ast for an idle thread
+	 * Handle ASTs for all threads
+	 * except idle processor threads.
 	 */
-	if (self->state & TH_IDLE)
-		return;
-
-	/*
-	 * Check for preemption
-	 */
-	if ((reasons & AST_URGENT) && (wait_queue_assert_possible(self))) {
-		reasons &= ~AST_URGENT;
-		if ((reasons & (AST_BLOCK|AST_QUANTUM)) == 0) {
-			mp_disable_preemption();
-			mypr = current_processor();
-			if (csw_needed(self, mypr)) {
-				reasons |= (mypr->first_quantum ? AST_BLOCK : AST_QUANTUM);
+	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);
 			}
-			mp_enable_preemption();
-		}
-		if (reasons & (AST_BLOCK | AST_QUANTUM)) {
-			counter(c_ast_taken_block++);
-			thread_block_reason((void (*)(void))0, 
-								(reasons & (AST_BLOCK | AST_QUANTUM)));
+
+			reasons &= ~AST_PREEMPTION;
 		}
-		if (reasons == 0)
-			return;
-	}
+
+		/*
+		 * The kernel preempt traps
+		 * skip all other ASTs.
+		 */
+		if (!preempt_trap) {
+			ml_set_interrupts_enabled(enable);
 
 #ifdef	MACH_BSD
-	/*
-	 * Check for BSD hardcoded hooks 
-	 */
-	if (reasons & AST_BSD) {
-		thread_ast_clear(act,AST_BSD);
-		bsd_ast(act);
-	}
-	if (reasons & AST_BSD_INIT) {
-		thread_ast_clear(act,AST_BSD_INIT);
-		bsdinit_task();
-	}
+			/*
+			 * 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
 
-#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 */
+			/* 
+			 * Thread APC hook.
+			 */
+			if (reasons & AST_APC)
+				act_execute_returnhandlers();
 
-	/* 
-	 * migration APC hook 
-	 */
-	if (reasons & AST_APC) {
-		act_execute_returnhandlers();
-	}
+			ml_set_interrupts_enabled(FALSE);
 
-	/* 
-	 *	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.
-	 */
-	reasons &= (AST_BLOCK | AST_QUANTUM);
-	if (reasons == 0) {
-		mp_disable_preemption();
-		mypr = current_processor();
-		if (csw_needed(self, mypr)) {
-			reasons = (mypr->first_quantum ? AST_BLOCK : AST_QUANTUM);
+			/* 
+			 * 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);
+			}
 		}
-		mp_enable_preemption();
-	}
-	if ((reasons & (AST_BLOCK | AST_QUANTUM)) &&
-	    (wait_queue_assert_possible(self))) {
-		counter(c_ast_taken_block++);
-		/*
-		 * JMM - SMP machines don't like blocking at a continuation
-		 * here - why not?  Could be a combination of set_state and
-		 * suspension on the thread_create_running API?
-		 *
-		 * thread_block_reason(thread_exception_return, reasons);
-		 */
-		thread_block_reason((void (*)(void))0, reasons);
 	}
+
+	ml_set_interrupts_enabled(enable);
 }
 
+/*
+ * Called at splsched.
+ */
 void
-ast_check(void)
+ast_check(
+	processor_t		processor)
 {
-	register int		mycpu;
-	register processor_t	myprocessor;
-	register thread_t	thread = current_thread();
-	spl_t			s = splsched();
+	register thread_t		self = processor->active_thread;
 
-	mp_disable_preemption();
-	mycpu = cpu_number();
+	processor->current_pri = self->sched_pri;
+	if (processor->state == PROCESSOR_RUNNING) {
+		register ast_t		preempt;
+processor_running:
 
-	/*
-	 *	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.
+		 *	Propagate thread ast to processor.
 		 */
-	    	break;
-
-#if	NCPUS > 1
-	    case PROCESSOR_ASSIGN:
-	        /*
-		 * 	Need ast to force action thread onto processor.
-		 *
-		 * XXX  Should check if action thread is already there.
-		 */
-		ast_on(AST_BLOCK);
-		break;
-#endif	/* NCPUS > 1 */
-
-	    case PROCESSOR_RUNNING:
-	    case PROCESSOR_SHUTDOWN:
-		/*
-		 *	Propagate thread ast to processor.  If we already
-		 *	need an ast, don't look for more reasons.
-		 */
-		ast_propagate(current_act()->ast);
-		if (ast_needed(mycpu))
-			break;
+		ast_propagate(self->top_act->ast);
 
 		/*
 		 *	Context switch check.
 		 */
-		if (csw_needed(thread, myprocessor)) {
-			ast_on((myprocessor->first_quantum ?
-			       AST_BLOCK : AST_QUANTUM));
-		}
-		break;
-
-	    default:
-	        panic("ast_check: Bad processor state");
+		if ((preempt = csw_check(self, processor)) != AST_NONE)
+			ast_on(preempt);
 	}
-	mp_enable_preemption();
-	splx(s);
-}
-
-/*
- * JMM - Temporary exports to other components
- */
-#undef ast_on
-#undef ast_off
-
-void
-ast_on(ast_t reason)
-{
-	boolean_t	intr;
-
-	intr = ml_set_interrupts_enabled(FALSE);
-	ast_on_fast(reason);
-	(void *)ml_set_interrupts_enabled(intr);
-}
-
-void
-ast_off(ast_t reason)
-{
-	ast_off_fast(reason);
+	else
+	if (	processor->state == PROCESSOR_DISPATCHING	||
+			processor->state == PROCESSOR_IDLE			) {
+		return;
+	}
+	else
+	if (processor->state == PROCESSOR_SHUTDOWN)
+		goto processor_running;
 }