X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/1c79356b52d46aa6b508fb032f5ae709b1f2897b..593a1d5fd87cdf5b46dd5fcb84467b432cea0f91:/osfmk/kern/ast.c

diff --git a/osfmk/kern/ast.c b/osfmk/kern/ast.c
index f454fe9a3..f0b75b59a 100644
--- a/osfmk/kern/ast.c
+++ b/osfmk/kern/ast.c
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2008 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * @OSF_COPYRIGHT@
@@ -60,242 +66,146 @@
  */
 
 #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>
-#include <kern/thread_swap.h>
 #include <kern/processor.h>
 #include <kern/spl.h>
+#include <kern/wait_queue.h>
 #include <mach/policy.h>
-#if	TASK_SWAPPER
-#include <kern/task_swap.h>
-#endif	/* TASK_SWAPPER */
-
-volatile ast_t need_ast[NCPUS];
+#include <machine/trap.h> // for CHUD AST hook
 
 void
 ast_init(void)
 {
-#ifndef	MACHINE_AST
-	register int i;
-
-	for (i=0; i<NCPUS; i++) {
-		need_ast[i] = AST_NONE;
-	}
-#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
-
-	mp_disable_preemption();
-	mycpu = cpu_number();
-	reasons = need_ast[mycpu] & mask;
-	need_ast[mycpu] &= ~reasons;
-	mp_enable_preemption();
-
-	ml_set_interrupts_enabled(interrupt);
-
-	/*
-	 * No ast for an idle thread
-	 */
-	if (self->state & TH_IDLE)
-		return;
+	boolean_t		preempt_trap = (reasons == AST_PREEMPTION);
+	ast_t			*myast = ast_pending();
+	thread_t		thread = current_thread();
 
 	/*
-	 * Check for preemption
+	 * CHUD hook - all threads including idle processor threads
 	 */
-	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(perfASTHook) {
+		if(*myast & AST_CHUD_ALL) {
+			perfASTHook(0, NULL, 0, 0);
+			
+			if(*myast == AST_NONE) {
+				return; // nothing left to do
 			}
-			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)));
 		}
-		if (reasons == 0)
-			return;
+	} else {
+		*myast &= ~AST_CHUD_ALL;
 	}
 
-#ifdef	MACH_BSD
+	reasons &= *myast;
+	*myast &= ~reasons;
+
 	/*
-	 * Check for BSD hardcoded hooks 
+	 * Handle ASTs for all threads
+	 * except idle processor threads.
 	 */
-	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();
-	}
-#endif
+	if (!(thread->state & TH_IDLE)) {
+		/*
+		 * Check for urgent preemption.
+		 */
+		if (	(reasons & AST_URGENT)				&&
+				wait_queue_assert_possible(thread)		) {
+			if (reasons & AST_PREEMPT) {
+				counter(c_ast_taken_block++);
+				thread_block_reason(THREAD_CONTINUE_NULL, NULL,
+										AST_PREEMPT | AST_URGENT);
+			}
 
-#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 */
+			reasons &= ~AST_PREEMPTION;
 		}
-		mp_enable_preemption();
-		splx(s);
-	}
-#endif	/* TASK_SWAPPER */
 
-	/* 
-	 * migration APC hook 
-	 */
-	if (reasons & AST_APC) {
-		act_execute_returnhandlers();
-	}
-
-	/* 
-	 *	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);
-		}
-		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);
+		 * The kernel preempt traps
+		 * skip all other ASTs.
 		 */
-		thread_block_reason((void (*)(void))0, reasons);
-	}
-}
+		if (!preempt_trap) {
+			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();
+#ifdef	MACH_BSD
+			/*
+			 * Handle BSD hook.
+			 */
+			if (reasons & AST_BSD) {
+				thread_ast_clear(thread, AST_BSD);
+				bsd_ast(thread);
+			}
+#endif
 
-	/*
-	 *	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;
+			/* 
+			 * Thread APC hook.
+			 */
+			if (reasons & AST_APC)
+				act_execute_returnhandlers();
 
-#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 */
+			ml_set_interrupts_enabled(FALSE);
 
-	    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;
+			/* 
+			 * Check for preemption.
+			 */
+			if (reasons & AST_PREEMPT) {
+				processor_t		myprocessor = current_processor();
 
-		/*
-		 *	Context switch check.
-		 */
-		if (csw_needed(thread, myprocessor)) {
-			ast_on((myprocessor->first_quantum ?
-			       AST_BLOCK : AST_QUANTUM));
+				if (csw_needed(thread, myprocessor))
+					reasons = AST_PREEMPT;
+				else
+					reasons = AST_NONE;
+			}
+			if (	(reasons & AST_PREEMPT)				&&
+					wait_queue_assert_possible(thread)		) {		
+				counter(c_ast_taken_block++);
+				thread_block_reason((thread_continue_t)thread_exception_return, NULL, AST_PREEMPT);
+			}
 		}
-		break;
-
-	    default:
-	        panic("ast_check: Bad processor state");
 	}
-	mp_enable_preemption();
-	splx(s);
+
+	ml_set_interrupts_enabled(enable);
 }
 
 /*
- * JMM - Temporary exports to other components
+ * Called at splsched.
  */
-#undef ast_on
-#undef ast_off
-
 void
-ast_on(ast_t reason)
+ast_check(
+	processor_t		processor)
 {
-	boolean_t	intr;
+	thread_t			thread = processor->active_thread;
 
-	intr = ml_set_interrupts_enabled(FALSE);
-	ast_on_fast(reason);
-	(void *)ml_set_interrupts_enabled(intr);
-}
+	processor->current_pri = thread->sched_pri;
+	if (	processor->state == PROCESSOR_RUNNING		||
+			processor->state == PROCESSOR_SHUTDOWN		) {
+		ast_t			preempt;
 
-void
-ast_off(ast_t reason)
-{
-	ast_off_fast(reason);
+		/*
+		 *	Propagate thread ast to processor.
+		 */
+		ast_propagate(thread->ast);
+
+		/*
+		 *	Context switch check.
+		 */
+		if ((preempt = csw_check(thread, processor)) != AST_NONE)
+			ast_on(preempt);
+	}
 }