/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
- *
- * @APPLE_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 Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Copyright (c) 2000-2012 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * 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.
+ *
+ * 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.
- *
- * @APPLE_LICENSE_HEADER_END@
+ * 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_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* @OSF_COPYRIGHT@
*/
-/*
+/*
* Mach Operating System
* Copyright (c) 1991,1990,1989 Carnegie Mellon University
* All Rights Reserved.
- *
+ *
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
- *
+ *
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
- *
+ *
* Carnegie Mellon requests users of this software to return to
- *
+ *
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
- *
+ *
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
#ifndef _KERN_AST_H_
#define _KERN_AST_H_
-#include <cpus.h>
-#include <platforms.h>
#include <kern/assert.h>
-#include <kern/cpu_number.h>
#include <kern/macro_help.h>
-#include <kern/lock.h>
#include <kern/spl.h>
-#include <machine/ast.h>
/*
- * A CPU takes an AST when it is about to return to user code.
- * Instead of going back to user code, it calls ast_taken.
- * Machine-dependent code is responsible for maintaining
- * a set of reasons for an AST, and passing this set to ast_taken.
+ * A processor detects an AST when it is about to return from an
+ * interrupt context, and calls ast_taken_kernel or ast_taken_user
+ * depending on whether it was returning from userspace or kernelspace.
+ *
+ * Machine-dependent code is responsible for maintaining
+ * a set of reasons for an AST.
*/
-typedef unsigned int ast_t;
+typedef uint32_t ast_t;
/*
- * Bits for reasons
+ * When returning from interrupt/trap context to kernel mode,
+ * if AST_URGENT is set, then ast_taken_kernel is called, for
+ * instance to effect preemption of a kernel thread by a realtime
+ * thread.
+ *
+ * This is also done when re-enabling preemption or re-enabling
+ * interrupts, since an AST may have been set while preemption
+ * was disabled, and it should take effect as soon as possible.
+ *
+ * When returning from interrupt/trap/syscall context to user
+ * mode, any and all ASTs that are pending should be handled by
+ * calling ast_taken_user.
+ *
+ * If a thread context switches, only ASTs not in AST_PER_THREAD
+ * remain active. The per-thread ASTs are stored in the thread_t
+ * and re-enabled when the thread context switches back.
+ *
+ * Typically the preemption ASTs are set as a result of threads
+ * becoming runnable, threads changing priority, or quantum
+ * expiration. If a thread becomes runnable and is chosen
+ * to run on another processor, cause_ast_check() may be called
+ * to IPI that processor and request csw_check() be run there.
*/
-#define AST_HALT 0x01
-#define AST_TERMINATE 0x02
-#define AST_BLOCK 0x04
-#define AST_QUANTUM 0x08
-#define AST_URGENT 0x10
-#define AST_APC 0x20 /* migration APC hook */
+
/*
- * JMM - This is here temporarily. AST_BSD is used to simulate a
- * general purpose mechanism for setting asynchronous procedure calls
- * from the outside.
+ * Bits for reasons
+ * TODO: Split the context switch and return-to-user AST namespaces
+ * NOTE: Some of these are exported as the 'reason' code in scheduler tracepoints
*/
-#define AST_BSD 0x80
-#define AST_BSD_INIT 0x100
+#define AST_PREEMPT 0x01
+#define AST_QUANTUM 0x02
+#define AST_URGENT 0x04
+#define AST_HANDOFF 0x08
+#define AST_YIELD 0x10
+#define AST_APC 0x20 /* migration APC hook */
+#define AST_LEDGER 0x40
+#define AST_BSD 0x80
+#define AST_KPERF 0x100 /* kernel profiling */
+#define AST_MACF 0x200 /* MACF user ret pending */
+#define AST_RESET_PCS 0x400 /* restartable ranges */
+#define AST_ARCADE 0x800 /* arcade subsciption support */
+#define AST_GUARD 0x1000
+#define AST_TELEMETRY_USER 0x2000 /* telemetry sample requested on interrupt from userspace */
+#define AST_TELEMETRY_KERNEL 0x4000 /* telemetry sample requested on interrupt from kernel */
+#define AST_TELEMETRY_PMI 0x8000 /* telemetry sample requested on PMI */
+#define AST_SFI 0x10000 /* Evaluate if SFI wait is needed before return to userspace */
+#define AST_DTRACE 0x20000
+#define AST_TELEMETRY_IO 0x40000 /* telemetry sample requested for I/O */
+#define AST_KEVENT 0x80000
+#define AST_REBALANCE 0x100000 /* thread context switched due to rebalancing */
+#define AST_UNQUIESCE 0x200000 /* catch unquiesced processor before returning to userspace */
+
+#define AST_NONE 0x00
+#define AST_ALL (~AST_NONE)
+
+#define AST_SCHEDULING (AST_PREEMPTION | AST_YIELD | AST_HANDOFF)
+#define AST_PREEMPTION (AST_PREEMPT | AST_QUANTUM | AST_URGENT)
+
+#define AST_TELEMETRY_ALL (AST_TELEMETRY_USER | AST_TELEMETRY_KERNEL | \
+ AST_TELEMETRY_PMI | AST_TELEMETRY_IO)
+
+/* Per-thread ASTs follow the thread at context-switch time. */
+#define AST_PER_THREAD (AST_APC | AST_BSD | AST_MACF | AST_RESET_PCS | \
+ AST_ARCADE | AST_LEDGER | AST_GUARD | AST_TELEMETRY_ALL | AST_KEVENT)
+
+/* Handle AST_URGENT detected while in the kernel */
+extern void ast_taken_kernel(void);
+
+/* Handle an AST flag set while returning to user mode (may continue via thread_exception_return) */
+extern void ast_taken_user(void);
-#define AST_NONE 0x00
-#define AST_ALL (~AST_NONE)
+/* Check for pending ASTs */
+extern void ast_check(processor_t processor);
-#define AST_SCHEDULING (AST_HALT | AST_TERMINATE | AST_BLOCK)
-#define AST_PREEMPT (AST_BLOCK | AST_QUANTUM | AST_URGENT)
+/* Pending ast mask for the current processor */
+extern ast_t *ast_pending(void);
-extern volatile ast_t need_ast[NCPUS];
+/* Set AST flags on current processor */
+extern void ast_on(ast_t reasons);
-#ifdef MACHINE_AST
-/*
- * machine/ast.h is responsible for defining aston and astoff.
- */
-#else /* MACHINE_AST */
+/* Clear AST flags on current processor */
+extern void ast_off(ast_t reasons);
-#define aston(mycpu)
-#define astoff(mycpu)
+/* Consume specified AST flags from current processor */
+extern ast_t ast_consume(ast_t reasons);
-#endif /* MACHINE_AST */
+/* Read specified AST flags from current processor */
+extern ast_t ast_peek(ast_t reasons);
-/* Initialize module */
-extern void ast_init(void);
+/* Re-set current processor's per-thread AST flags to those set on thread */
+extern void ast_context(thread_t thread);
-/* Handle ASTs */
-extern void ast_taken(
- ast_t mask,
- boolean_t enable);
-
-/* Check for pending ASTs */
-extern void ast_check(void);
+/* Propagate ASTs set on a thread to the current processor */
+extern void ast_propagate(thread_t thread);
/*
- * Per-thread ASTs are reset at context-switch time.
+ * Set an AST on a thread with thread_ast_set.
+ *
+ * You can then propagate it to the current processor with ast_propagate(),
+ * or tell another processor to act on it with cause_ast_check().
+ *
+ * See act_set_ast() for an example.
*/
-#ifndef MACHINE_AST_PER_THREAD
-#define MACHINE_AST_PER_THREAD 0
-#endif
+#define thread_ast_set(act, reason) ((void)os_atomic_or(&(act)->ast, (reason), relaxed))
+#define thread_ast_clear(act, reason) ((void)os_atomic_andnot(&(act)->ast, (reason), relaxed))
-#define AST_PER_THREAD ( AST_HALT | AST_TERMINATE | AST_APC | AST_BSD | \
- MACHINE_AST_PER_THREAD )
-/*
- * ast_needed(), ast_on(), ast_off(), ast_context(), and ast_propagate()
- * assume splsched.
- */
-#define ast_needed(mycpu) need_ast[mycpu]
-
-#define ast_on_fast(reasons) \
-MACRO_BEGIN \
- int mycpu = cpu_number(); \
- if ((need_ast[mycpu] |= (reasons)) != AST_NONE) \
- { aston(mycpu); } \
-MACRO_END
-
-#define ast_off_fast(reasons) \
-MACRO_BEGIN \
- int mycpu = cpu_number(); \
- if ((need_ast[mycpu] &= ~(reasons)) == AST_NONE) \
- { astoff(mycpu); } \
-MACRO_END
-
-#define ast_propagate(reasons) ast_on(reasons)
-
-#define ast_context(act, mycpu) \
-MACRO_BEGIN \
- assert((mycpu) == cpu_number()); \
- if ((need_ast[mycpu] = \
- ((need_ast[mycpu] &~ AST_PER_THREAD) | (act)->ast)) != AST_NONE) \
- { aston(mycpu); } \
- else \
- { astoff(mycpu); } \
-MACRO_END
-
-#define ast_on(reason) ast_on_fast(reason)
-#define ast_off(reason) ast_off_fast(reason)
-
-#define thread_ast_set(act, reason) ((act)->ast |= (reason))
-#define thread_ast_clear(act, reason) ((act)->ast &= ~(reason))
-#define thread_ast_clear_all(act) ((act)->ast = AST_NONE)
+#ifdef MACH_BSD
-/*
- * NOTE: if thread is the current thread, thread_ast_set() should
- * be followed by ast_propagate().
- */
+extern void act_set_astbsd(thread_t);
+extern void bsd_ast(thread_t);
-#ifdef MACH_KERNEL_PRIVATE
+#endif /* MACH_BSD */
-#define ast_urgency() (need_ast[cpu_number()] & AST_URGENT)
+#ifdef CONFIG_DTRACE
+extern void ast_dtrace_on(void);
+extern void dtrace_ast(void);
+#endif /* CONFIG_DTRACE */
-#endif /* MACH_KERNEL_PRIVATE */
+extern void kevent_ast(thread_t thread, uint16_t bits);
+extern void act_set_astkevent(thread_t thread, uint16_t bits);
+extern uint16_t act_clear_astkevent(thread_t thread, uint16_t bits);
+extern void act_set_ast_reset_pcs(thread_t thread);
#endif /* _KERN_AST_H_ */
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