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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, 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. */ /* */ /* * kern/ast.h: Definitions for Asynchronous System Traps. */ #ifndef _KERN_AST_H_ #define _KERN_AST_H_ #include <kern/assert.h> #include <kern/macro_help.h> #include <kern/spl.h> /* * 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 uint32_t ast_t; /* * 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. */ /* * 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_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); /* Check for pending ASTs */ extern void ast_check(processor_t processor); /* Pending ast mask for the current processor */ extern ast_t *ast_pending(void); /* Set AST flags on current processor */ extern void ast_on(ast_t reasons); /* Clear AST flags on current processor */ extern void ast_off(ast_t reasons); /* Consume specified AST flags from current processor */ extern ast_t ast_consume(ast_t reasons); /* Read specified AST flags from current processor */ extern ast_t ast_peek(ast_t reasons); /* Re-set current processor's per-thread AST flags to those set on thread */ extern void ast_context(thread_t thread); /* Propagate ASTs set on a thread to the current processor */ extern void ast_propagate(thread_t thread); /* * 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. */ #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)) #ifdef MACH_BSD extern void act_set_astbsd(thread_t); extern void bsd_ast(thread_t); #endif /* MACH_BSD */ #ifdef CONFIG_DTRACE extern void ast_dtrace_on(void); extern void dtrace_ast(void); #endif /* CONFIG_DTRACE */ 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_ */