zfs-builds-mm/zfs-2.0.0-rc6/include/os/freebsd/spl/sys/callb.h
2020-11-15 11:35:49 +01:00

213 lines
7 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_CALLB_H
#define _SYS_CALLB_H
#include <sys/condvar.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* definitions of callback classes (c_class)
*
* Callbacks belong in the same class if (1) their callback routines
* do the same kind of processing (ideally, using the same callback function)
* and (2) they can/should be executed at the same time in a cpr
* suspend/resume operation.
*
* Note: The DAEMON class, in particular, is for stopping kernel threads
* and nothing else. The CALLB_* macros below should be used to deal
* with kernel threads, and the callback function should be callb_generic_cpr.
* Another idiosyncrasy of the DAEMON class is that if a suspend operation
* fails, some of the callback functions may be called with the RESUME
* code which were never called with SUSPEND. Not a problem currently,
* but see bug 4201851.
*/
#define CB_CL_CPR_DAEMON 0
#define CB_CL_CPR_VM 1
#define CB_CL_CPR_CALLOUT 2
#define CB_CL_CPR_OBP 3
#define CB_CL_CPR_FB 4
#define CB_CL_PANIC 5
#define CB_CL_CPR_RPC 6
#define CB_CL_CPR_PROMPRINTF 7
#define CB_CL_UADMIN 8
#define CB_CL_CPR_PM 9
#define CB_CL_HALT 10
#define CB_CL_CPR_DMA 11
#define CB_CL_CPR_POST_USER 12
#define CB_CL_UADMIN_PRE_VFS 13
#define CB_CL_MDBOOT CB_CL_UADMIN
#define CB_CL_ENTER_DEBUGGER 14
#define CB_CL_CPR_POST_KERNEL 15
#define CB_CL_CPU_DEEP_IDLE 16
#define NCBCLASS 17 /* CHANGE ME if classes are added/removed */
/*
* CB_CL_CPR_DAEMON class specific definitions are given below:
*/
/*
* code for CPR callb_execute_class
*/
#define CB_CODE_CPR_CHKPT 0
#define CB_CODE_CPR_RESUME 1
typedef void * callb_id_t;
/*
* Per kernel thread structure for CPR daemon callbacks.
* Must be protected by either a existing lock in the daemon or
* a new lock created for such a purpose.
*/
typedef struct callb_cpr {
kmutex_t *cc_lockp; /* lock to protect this struct */
char cc_events; /* various events for CPR */
callb_id_t cc_id; /* callb id address */
kcondvar_t cc_callb_cv; /* cv for callback waiting */
kcondvar_t cc_stop_cv; /* cv to checkpoint block */
} callb_cpr_t;
/*
* cc_events definitions
*/
#define CALLB_CPR_START 1 /* a checkpoint request's started */
#define CALLB_CPR_SAFE 2 /* thread is safe for CPR */
#define CALLB_CPR_ALWAYS_SAFE 4 /* thread is ALWAYS safe for CPR */
/*
* Used when checking that all kernel threads are stopped.
*/
#define CALLB_MAX_RETRY 3 /* when waiting for kthread to sleep */
#define CALLB_THREAD_DELAY 10 /* ticks allowed to reach sleep */
#define CPR_KTHREAD_TIMEOUT_SEC 90 /* secs before callback times out -- */
/* due to pwr mgmt of disks, make -- */
/* big enough for worst spinup time */
/*
*
* CALLB_CPR_INIT macro is used by kernel threads to add their entry to
* the callback table and perform other initialization. It automatically
* adds the thread as being in the callback class CB_CL_CPR_DAEMON.
*
* cp - ptr to the callb_cpr_t structure for this kernel thread
*
* lockp - pointer to mutex protecting the callb_cpr_t struct
*
* func - pointer to the callback function for this kernel thread.
* It has the prototype boolean_t <func>(void *arg, int code)
* where: arg - ptr to the callb_cpr_t structure
* code - not used for this type of callback
* returns: B_TRUE if successful; B_FALSE if unsuccessful.
*
* name - a string giving the name of the kernel thread
*
* Note: lockp is the lock to protect the callb_cpr_t (cp) structure
* later on. No lock held is needed for this initialization.
*/
#define CALLB_CPR_INIT(cp, lockp, func, name) { \
strlcpy(curthread->td_name, (name), \
sizeof (curthread->td_name)); \
bzero((caddr_t)(cp), sizeof (callb_cpr_t)); \
(cp)->cc_lockp = lockp; \
(cp)->cc_id = callb_add(func, (void *)(cp), \
CB_CL_CPR_DAEMON, name); \
cv_init(&(cp)->cc_callb_cv, NULL, CV_DEFAULT, NULL); \
cv_init(&(cp)->cc_stop_cv, NULL, CV_DEFAULT, NULL); \
}
#ifndef __lock_lint
#define CALLB_CPR_ASSERT(cp) ASSERT(MUTEX_HELD((cp)->cc_lockp));
#else
#define CALLB_CPR_ASSERT(cp)
#endif
/*
* Some threads (like the idle threads) do not adhere to the callback
* protocol and are always considered safe. Such threads must never exit.
* They register their presence by calling this macro during their
* initialization.
*
* Args:
* t - thread pointer of the client kernel thread
* name - a string giving the name of the kernel thread
*/
#define CALLB_CPR_INIT_SAFE(t, name) { \
(void) callb_add_thread(callb_generic_cpr_safe, \
(void *) &callb_cprinfo_safe, CB_CL_CPR_DAEMON, \
name, t); \
}
/*
* The lock to protect cp's content must be held before
* calling the following two macros.
*
* Any code region between CALLB_CPR_SAFE_BEGIN and CALLB_CPR_SAFE_END
* is safe for checkpoint/resume.
*/
#define CALLB_CPR_SAFE_BEGIN(cp) { \
CALLB_CPR_ASSERT(cp) \
(cp)->cc_events |= CALLB_CPR_SAFE; \
if ((cp)->cc_events & CALLB_CPR_START) \
cv_signal(&(cp)->cc_callb_cv); \
}
#define CALLB_CPR_SAFE_END(cp, lockp) { \
CALLB_CPR_ASSERT(cp) \
while ((cp)->cc_events & CALLB_CPR_START) \
cv_wait(&(cp)->cc_stop_cv, lockp); \
(cp)->cc_events &= ~CALLB_CPR_SAFE; \
}
/*
* cv_destroy is nop right now but may be needed in the future.
*/
#define CALLB_CPR_EXIT(cp) { \
CALLB_CPR_ASSERT(cp) \
(cp)->cc_events |= CALLB_CPR_SAFE; \
if ((cp)->cc_events & CALLB_CPR_START) \
cv_signal(&(cp)->cc_callb_cv); \
mutex_exit((cp)->cc_lockp); \
(void) callb_delete((cp)->cc_id); \
cv_destroy(&(cp)->cc_callb_cv); \
cv_destroy(&(cp)->cc_stop_cv); \
}
extern callb_cpr_t callb_cprinfo_safe;
extern callb_id_t callb_add(boolean_t (*)(void *, int), void *, int, char *);
extern callb_id_t callb_add_thread(boolean_t (*)(void *, int),
void *, int, char *, kthread_id_t);
extern int callb_delete(callb_id_t);
extern void callb_execute(callb_id_t, int);
extern void *callb_execute_class(int, int);
extern boolean_t callb_generic_cpr(void *, int);
extern boolean_t callb_generic_cpr_safe(void *, int);
extern boolean_t callb_is_stopped(kthread_id_t, caddr_t *);
extern void callb_lock_table(void);
extern void callb_unlock_table(void);
#ifdef __cplusplus
}
#endif
#endif /* _SYS_CALLB_H */