FEATURES: document various missed changes

[unleashed/lotheac.git] / include / sys / strsubr.h

/*
 * 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 (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */


/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _SYS_STRSUBR_H
#define _SYS_STRSUBR_H

/*
 * WARNING:
 * Everything in this file is private, belonging to the
 * STREAMS subsystem.  The only guarantee made about the
 * contents of this file is that if you include it, your
 * code will not port to the next release.
 */
#include <sys/stream.h>
#include <sys/stropts.h>
#include <sys/kstat.h>
#include <sys/uio.h>
#include <sys/proc.h>
#include <sys/netstack.h>
#include <sys/modhash.h>

#ifdef  __cplusplus
extern "C" {
#endif

/*
 * In general, the STREAMS locks are disjoint; they are only held
 * locally, and not simultaneously by a thread.  However, module
 * code, including at the stream head, requires some locks to be
 * acquired in order for its safety.
 *      1. Stream level claim.  This prevents the value of q_next
 *              from changing while module code is executing.
 *      2. Queue level claim.  This prevents the value of q_ptr
 *              from changing while put or service code is executing.
 *              In addition, it provides for queue single-threading
 *              for QPAIR and PERQ MT-safe modules.
 *      3. Stream head lock.  May be held by the stream head module
 *              to implement a read/write/open/close monitor.
 *         Note: that the only types of twisted stream supported are
 *         the pipe and transports which have read and write service
 *         procedures on both sides of the twist.
 *      4. Queue lock.  May be acquired by utility routines on
 *              behalf of a module.
 */

/*
 * In general, sd_lock protects the consistency of the stdata
 * structure.  Additionally, it is used with sd_monitor
 * to implement an open/close monitor.  In particular, it protects
 * the following fields:
 *      sd_iocblk
 *      sd_flag
 *      sd_copyflag
 *      sd_iocid
 *      sd_iocwait
 *      sd_sidp
 *      sd_pgidp
 *      sd_wroff
 *      sd_tail
 *      sd_rerror
 *      sd_werror
 *      sd_pushcnt
 *      sd_sigflags
 *      sd_siglist
 *      sd_pollist
 *      sd_mark
 *      sd_closetime
 *      sd_wakeq
 *      sd_maxblk
 *
 * The following fields are modified only by the allocator, which
 * has exclusive access to them at that time:
 *      sd_wrq
 *      sd_strtab
 *
 * The following field is protected by the overlying file system
 * code, guaranteeing single-threading of opens:
 *      sd_vnode
 *
 * Stream-level locks should be acquired before any queue-level locks
 *      are acquired.
 *
 * The stream head write queue lock(sd_wrq) is used to protect the
 * fields qn_maxpsz and qn_minpsz because freezestr() which is
 * necessary for strqset() only gets the queue lock.
 */

/*
 * Function types for the parameterized stream head.
 * The msgfunc_t takes the parameters:
 *      msgfunc(vnode_t *vp, mblk_t *mp, strwakeup_t *wakeups,
 *              strsigset_t *firstmsgsigs, strsigset_t *allmsgsigs,
 *              strpollset_t *pollwakeups);
 * It returns an optional message to be processed by the stream head.
 *
 * The parameters for errfunc_t are:
 *      errfunc(vnode *vp, int ispeek, int *clearerr);
 * It returns an errno and zero if there was no pending error.
 */
typedef uint_t  strwakeup_t;
typedef uint_t  strsigset_t;
typedef short   strpollset_t;
typedef uintptr_t callbparams_id_t;
typedef mblk_t  *(*msgfunc_t)(vnode_t *, mblk_t *, strwakeup_t *,
                        strsigset_t *, strsigset_t *, strpollset_t *);
typedef int     (*errfunc_t)(vnode_t *, int, int *);

/*
 * Per stream sd_lock in putnext may be replaced by per cpu stream_putlocks
 * each living in a separate cache line. putnext/canputnext grabs only one of
 * stream_putlocks while strlock() (called on behalf of insertq()/removeq())
 * acquires all stream_putlocks. Normally stream_putlocks are only employed
 * for highly contended streams that have SQ_CIPUT queues in the critical path
 * (e.g. NFS/UDP stream).
 *
 * stream_putlocks are dynamically assigned to stdata structure through
 * sd_ciputctrl pointer possibly when a stream is already in use. Since
 * strlock() uses stream_putlocks only under sd_lock acquiring sd_lock when
 * assigning stream_putlocks to the stream ensures synchronization with
 * strlock().
 *
 * For lock ordering purposes stream_putlocks are treated as the extension of
 * sd_lock and are always grabbed right after grabbing sd_lock and released
 * right before releasing sd_lock except putnext/canputnext where only one of
 * stream_putlocks locks is used and where it is the first lock to grab.
 */

typedef struct ciputctrl_str {
        union _ciput_un {
                uchar_t pad[64];
                struct _ciput_str {
                        kmutex_t        ciput_lck;
                        ushort_t        ciput_cnt;
                } ciput_str;
        } ciput_un;
} ciputctrl_t;

#define ciputctrl_lock  ciput_un.ciput_str.ciput_lck
#define ciputctrl_count ciput_un.ciput_str.ciput_cnt

/*
 * Header for a stream: interface to rest of system.
 *
 * NOTE: While this is a consolidation-private structure, some unbundled and
 *       third-party products inappropriately make use of some of the fields.
 *       As such, please take care to not gratuitously change any offsets of
 *       existing members.
 */
typedef struct stdata {
        struct queue    *sd_wrq;        /* write queue */
        struct msgb     *sd_iocblk;     /* return block for ioctl */
        struct vnode    *sd_vnode;      /* pointer to associated vnode */
        struct streamtab *sd_strtab;    /* pointer to streamtab for stream */
        uint_t          sd_flag;        /* state/flags */
        uint_t          sd_iocid;       /* ioctl id */
        struct pid      *sd_sidp;       /* controlling session info */
        struct pid      *sd_pgidp;      /* controlling process group info */
        ushort_t        sd_tail;        /* reserved space in written mblks */
        ushort_t        sd_wroff;       /* write offset */
        int             sd_rerror;      /* error to return on read ops */
        int             sd_werror;      /* error to return on write ops */
        int             sd_pushcnt;     /* number of pushes done on stream */
        int             sd_sigflags;    /* logical OR of all siglist events */
        struct strsig   *sd_siglist;    /* pid linked list to rcv SIGPOLL sig */
        struct pollhead sd_pollist;     /* list of all pollers to wake up */
        struct msgb     *sd_mark;       /* "marked" message on read queue */
        clock_t         sd_closetime;   /* time to wait to drain q in close */
        kmutex_t        sd_lock;        /* protect head consistency */
        kcondvar_t      sd_monitor;     /* open/close/push/pop monitor */
        kcondvar_t      sd_iocmonitor;  /* ioctl single-threading */
        kcondvar_t      sd_refmonitor;  /* sd_refcnt monitor */
        ssize_t         sd_qn_minpsz;   /* These two fields are a performance */
        ssize_t         sd_qn_maxpsz;   /* enhancements, cache the values in */
                                        /* the stream head so we don't have */
                                        /* to ask the module below the stream */
                                        /* head to get this information. */
        struct stdata   *sd_mate;       /* pointer to twisted stream mate */
        kthread_id_t    sd_freezer;     /* thread that froze stream */
        kmutex_t        sd_reflock;     /* Protects sd_refcnt */
        int             sd_refcnt;      /* number of claimstr */
        uint_t          sd_wakeq;       /* strwakeq()'s copy of sd_flag */
        struct queue    *sd_struiordq;  /* sync barrier struio() read queue */
        struct queue    *sd_struiowrq;  /* sync barrier struio() write queue */
        char            sd_struiodnak;  /* defer NAK of M_IOCTL by rput() */
        struct msgb     *sd_struionak;  /* pointer M_IOCTL mblk(s) to NAK */
        caddr_t         sd_t_audit_data; /* For audit purposes only */
        ssize_t         sd_maxblk;      /* maximum message block size */
        uint_t          sd_rput_opt;    /* options/flags for strrput */
        uint_t          sd_wput_opt;    /* options/flags for write/putmsg */
        uint_t          sd_read_opt;    /* options/flags for strread */
        msgfunc_t       sd_rprotofunc;  /* rput M_*PROTO routine */
        msgfunc_t       sd_rputdatafunc; /* read M_DATA routine */
        msgfunc_t       sd_rmiscfunc;   /* rput routine (non-data/proto) */
        msgfunc_t       sd_wputdatafunc; /* wput M_DATA routine */
        errfunc_t       sd_rderrfunc;   /* read side error callback */
        errfunc_t       sd_wrerrfunc;   /* write side error callback */
        /*
         * support for low contention concurrent putnext.
         */
        ciputctrl_t     *sd_ciputctrl;
        uint_t          sd_nciputctrl;

        int             sd_anchor;      /* position of anchor in stream */
        /*
         * Service scheduling at the stream head.
         */
        kmutex_t        sd_qlock;
        struct queue    *sd_qhead;      /* Head of queues to be serviced. */
        struct queue    *sd_qtail;      /* Tail of queues to be serviced. */
        void            *sd_servid;     /* Service ID for bckgrnd schedule */
        ushort_t        sd_svcflags;    /* Servicing flags */
        short           sd_nqueues;     /* Number of queues in the list */
        kcondvar_t      sd_qcv;         /* Waiters for qhead to become empty */
        kcondvar_t      sd_zcopy_wait;
        uint_t          sd_copyflag;    /* copy-related flags */
        zoneid_t        sd_anchorzone;  /* Allow removal from same zone only */
        struct msgb     *sd_cmdblk;     /* reply from _I_CMD */
} stdata_t;

/*
 * stdata servicing flags.
 */
#define STRS_WILLSERVICE        0x01
#define STRS_SCHEDULED          0x02

#define STREAM_NEEDSERVICE(stp) ((stp)->sd_qhead != NULL)

/*
 * stdata flag field defines
 */
#define IOCWAIT         0x00000001      /* Someone is doing an ioctl */
#define RSLEEP          0x00000002      /* Someone wants to read/recv msg */
#define WSLEEP          0x00000004      /* Someone wants to write */
#define STRPRI          0x00000008      /* An M_PCPROTO is at stream head */
#define STRHUP          0x00000010      /* Device has vanished */
#define STWOPEN         0x00000020      /* waiting for 1st open */
#define STPLEX          0x00000040      /* stream is being multiplexed */
#define STRISTTY        0x00000080      /* stream is a terminal */
#define STRGETINPROG    0x00000100      /* (k)strgetmsg is running */
#define IOCWAITNE       0x00000200      /* STR_NOERROR ioctl running */
#define STRDERR         0x00000400      /* fatal read error from M_ERROR */
#define STWRERR         0x00000800      /* fatal write error from M_ERROR */
#define STRDERRNONPERSIST 0x00001000    /* nonpersistent read errors */
#define STWRERRNONPERSIST 0x00002000    /* nonpersistent write errors */
#define STRCLOSE        0x00004000      /* wait for a close to complete */
#define SNDMREAD        0x00008000      /* used for read notification */
#define OLDNDELAY       0x00010000      /* use old TTY semantics for */
                                        /* NDELAY reads and writes */
        /*              0x00020000         unused */
        /*              0x00040000         unused */
#define STRTOSTOP       0x00080000      /* block background writes */
#define STRCMDWAIT      0x00100000      /* someone is doing an _I_CMD */
        /*              0x00200000         unused */
#define STRMOUNT        0x00400000      /* stream is mounted */
#define STRNOTATMARK    0x00800000      /* Not at mark (when empty read q) */
#define STRDELIM        0x01000000      /* generate delimited messages */
#define STRATMARK       0x02000000      /* At mark (due to MSGMARKNEXT) */
#define STZCNOTIFY      0x04000000      /* wait for zerocopy mblk to be acked */
#define STRPLUMB        0x08000000      /* push/pop pending */
#define STREOF          0x10000000      /* End-of-file indication */
#define STREOPENFAIL    0x20000000      /* indicates if re-open has failed */
#define STRMATE         0x40000000      /* this stream is a mate */
#define STRHASLINKS     0x80000000      /* I_LINKs under this stream */

/*
 * Copy-related flags (sd_copyflag), set by SO_COPYOPT.
 */
#define STZCVMSAFE      0x00000001      /* safe to borrow file (segmapped) */
                                        /* pages instead of bcopy */
#define STZCVMUNSAFE    0x00000002      /* unsafe to borrow file pages */
#define STRCOPYCACHED   0x00000004      /* copy should NOT bypass cache */

/*
 * Options and flags for strrput (sd_rput_opt)
 */
#define SR_POLLIN       0x00000001      /* pollwakeup needed for band0 data */
#define SR_SIGALLDATA   0x00000002      /* Send SIGPOLL for all M_DATA */
#define SR_CONSOL_DATA  0x00000004      /* Consolidate M_DATA onto q_last */
#define SR_IGN_ZEROLEN  0x00000008      /* Ignore zero-length M_DATA */

/*
 * Options and flags for strwrite/strputmsg (sd_wput_opt)
 */
#define SW_SIGPIPE      0x00000001      /* Send SIGPIPE for write error */
#define SW_RECHECK_ERR  0x00000002      /* Recheck errors in strwrite loop */
#define SW_SNDZERO      0x00000004      /* send 0-length msg down pipe/FIFO */

/*
 * Options and flags for strread (sd_read_opt)
 */
#define RD_MSGDIS       0x00000001      /* read msg discard */
#define RD_MSGNODIS     0x00000002      /* read msg no discard */
#define RD_PROTDAT      0x00000004      /* read M_[PC]PROTO contents as data */
#define RD_PROTDIS      0x00000008      /* discard M_[PC]PROTO blocks and */
                                        /* retain data blocks */
/*
 * Flags parameter for strsetrputhooks() and strsetwputhooks().
 * These flags define the interface for setting the above internal
 * flags in sd_rput_opt and sd_wput_opt.
 */
#define SH_CONSOL_DATA  0x00000001      /* Consolidate M_DATA onto q_last */
#define SH_SIGALLDATA   0x00000002      /* Send SIGPOLL for all M_DATA */
#define SH_IGN_ZEROLEN  0x00000004      /* Drop zero-length M_DATA */

#define SH_SIGPIPE      0x00000100      /* Send SIGPIPE for write error */
#define SH_RECHECK_ERR  0x00000200      /* Recheck errors in strwrite loop */

/*
 * Each queue points to a sync queue (the inner perimeter) which keeps
 * track of the number of threads that are inside a given queue (sq_count)
 * and also is used to implement the asynchronous putnext
 * (by queuing messages if the queue can not be entered.)
 *
 * Messages are queued on sq_head/sq_tail including deferred qwriter(INNER)
 * messages. The sq_head/sq_tail list is a singly-linked list with
 * b_queue recording the queue and b_prev recording the function to
 * be called (either the put procedure or a qwriter callback function.)
 *
 * The sq_count counter tracks the number of threads that are
 * executing inside the perimeter or (in the case of outer perimeters)
 * have some work queued for them relating to the perimeter. The sq_rmqcount
 * counter tracks the subset which are in removeq() (usually invoked from
 * qprocsoff(9F)).
 *
 * In addition a module writer can declare that the module has an outer
 * perimeter (by setting D_MTOUTPERIM) in which case all inner perimeter
 * syncq's for the module point (through sq_outer) to an outer perimeter
 * syncq. The outer perimeter consists of the doubly linked list (sq_onext and
 * sq_oprev) linking all the inner perimeter syncq's with out outer perimeter
 * syncq. This is used to implement qwriter(OUTER) (an asynchronous way of
 * getting exclusive access at the outer perimeter) and outer_enter/exit
 * which are used by the framework to acquire exclusive access to the outer
 * perimeter during open and close of modules that have set D_MTOUTPERIM.
 *
 * In the inner perimeter case sq_save is available for use by machine
 * dependent code. sq_head/sq_tail are used to queue deferred messages on
 * the inner perimeter syncqs and to queue become_writer requests on the
 * outer perimeter syncqs.
 *
 * Note: machine dependent optimized versions of putnext may depend
 * on the order of sq_flags and sq_count (so that they can e.g.
 * read these two fields in a single load instruction.)
 *
 * Per perimeter SQLOCK/sq_count in putnext/put may be replaced by per cpu
 * sq_putlocks/sq_putcounts each living in a separate cache line. Obviously
 * sq_putlock[x] protects sq_putcount[x]. putnext/put routine will grab only 1
 * of sq_putlocks and update only 1 of sq_putcounts. strlock() and many
 * other routines in strsubr.c and ddi.c will grab all sq_putlocks (as well as
 * SQLOCK) and figure out the count value as the sum of sq_count and all of
 * sq_putcounts. The idea is to make critical fast path -- putnext -- much
 * faster at the expense of much less often used slower path like
 * strlock(). One known case where entersq/strlock is executed pretty often is
 * SpecWeb but since IP is SQ_CIOC and socket TCP/IP stream is nextless
 * there's no need to grab multiple sq_putlocks and look at sq_putcounts. See
 * strsubr.c for more comments.
 *
 * Note regular SQLOCK and sq_count are still used in many routines
 * (e.g. entersq(), rwnext()) in the same way as before sq_putlocks were
 * introduced.
 *
 * To understand when all sq_putlocks need to be held and all sq_putcounts
 * need to be added up one needs to look closely at putnext code. Basically if
 * a routine like e.g. wait_syncq() needs to be sure that perimeter is empty
 * all sq_putlocks/sq_putcounts need to be held/added up. On the other hand
 * there's no need to hold all sq_putlocks and count all sq_putcounts in
 * routines like leavesq()/dropsq() and etc. since the are usually exit
 * counterparts of entersq/outer_enter() and etc. which have already either
 * prevented put entry poins from executing or did not care about put
 * entrypoints. entersq() doesn't need to care about sq_putlocks/sq_putcounts
 * if the entry point has a shared access since put has the highest degree of
 * concurrency and such entersq() does not intend to block out put
 * entrypoints.
 *
 * Before sq_putcounts were introduced the standard way to wait for perimeter
 * to become empty was:
 *
 *      mutex_enter(SQLOCK(sq));
 *      while (sq->sq_count > 0) {
 *              sq->sq_flags |= SQ_WANTWAKEUP;
 *              cv_wait(&sq->sq_wait, SQLOCK(sq));
 *      }
 *      mutex_exit(SQLOCK(sq));
 *
 * The new way is:
 *
 *      mutex_enter(SQLOCK(sq));
 *      count = sq->sq_count;
 *      SQ_PUTLOCKS_ENTER(sq);
 *      SUM_SQ_PUTCOUNTS(sq, count);
 *      while (count != 0) {
 *              sq->sq_flags |= SQ_WANTWAKEUP;
 *              SQ_PUTLOCKS_EXIT(sq);
 *              cv_wait(&sq->sq_wait, SQLOCK(sq));
 *              count = sq->sq_count;
 *              SQ_PUTLOCKS_ENTER(sq);
 *              SUM_SQ_PUTCOUNTS(sq, count);
 *      }
 *      SQ_PUTLOCKS_EXIT(sq);
 *      mutex_exit(SQLOCK(sq));
 *
 * Note that SQ_WANTWAKEUP is set before dropping SQ_PUTLOCKS. This makes sure
 * putnext won't skip a wakeup.
 *
 * sq_putlocks are treated as the extension of SQLOCK for lock ordering
 * purposes and are always grabbed right after grabbing SQLOCK and released
 * right before releasing SQLOCK. This also allows dynamic creation of
 * sq_putlocks while holding SQLOCK (by making sq_ciputctrl non null even when
 * the stream is already in use). Only in putnext one of sq_putlocks
 * is grabbed instead of SQLOCK. putnext return path remembers what counter it
 * incremented and decrements the right counter on its way out.
 */

struct syncq {
        kmutex_t        sq_lock;        /* atomic access to syncq */
        uint16_t        sq_count;       /* # threads inside */
        uint16_t        sq_flags;       /* state and some type info */
        /*
         * Distributed syncq scheduling
         *  The list of queue's is handled by sq_head and
         *  sq_tail fields.
         *
         *  The list of events is handled by the sq_evhead and sq_evtail
         *  fields.
         */
        queue_t         *sq_head;       /* queue of deferred messages */
        queue_t         *sq_tail;       /* queue of deferred messages */
        mblk_t          *sq_evhead;     /* Event message on the syncq */
        mblk_t          *sq_evtail;
        uint_t          sq_nqueues;     /* # of queues on this sq */
        /*
         * Concurrency and condition variables
         */
        uint16_t        sq_type;        /* type (concurrency) of syncq */
        uint16_t        sq_rmqcount;    /* # threads inside removeq() */
        kcondvar_t      sq_wait;        /* block on this sync queue */
        kcondvar_t      sq_exitwait;    /* waiting for thread to leave the */
                                        /* inner perimeter */
        /*
         * Handling synchronous callbacks such as qtimeout and qbufcall
         */
        ushort_t        sq_callbflags;  /* flags for callback synchronization */
        callbparams_id_t sq_cancelid;   /* id of callback being cancelled */
        struct callbparams *sq_callbpend;       /* Pending callbacks */

        /*
         * Links forming an outer perimeter from one outer syncq and
         * a set of inner sync queues.
         */
        struct syncq    *sq_outer;      /* Pointer to outer perimeter */
        struct syncq    *sq_onext;      /* Linked list of syncq's making */
        struct syncq    *sq_oprev;      /* up the outer perimeter. */
        /*
         * support for low contention concurrent putnext.
         */
        ciputctrl_t     *sq_ciputctrl;
        uint_t          sq_nciputctrl;
        /*
         * Counter for the number of threads wanting to become exclusive.
         */
        uint_t          sq_needexcl;
        /*
         * These two fields are used for scheduling a syncq for
         * background processing. The sq_svcflag is protected by
         * SQLOCK lock.
         */
        struct syncq    *sq_next;       /* for syncq scheduling */
        void *          sq_servid;
        uint_t          sq_servcount;   /* # pending background threads */
        uint_t          sq_svcflags;    /* Scheduling flags     */
        clock_t         sq_tstamp;      /* Time when was enabled */
        /*
         * Maximum priority of the queues on this syncq.
         */
        pri_t           sq_pri;
};
typedef struct syncq syncq_t;

/*
 * sync queue scheduling flags (for sq_svcflags).
 */
#define SQ_SERVICE      0x1             /* being serviced */
#define SQ_BGTHREAD     0x2             /* awaiting service by bg thread */
#define SQ_DISABLED     0x4             /* don't put syncq in service list */

/*
 * FASTPUT bit in sd_count/putcount.
 */
#define SQ_FASTPUT      0x8000
#define SQ_FASTMASK     0x7FFF

/*
 * sync queue state flags
 */
#define SQ_EXCL         0x0001          /* exclusive access to inner */
                                        /*      perimeter */
#define SQ_BLOCKED      0x0002          /* qprocsoff */
#define SQ_FROZEN       0x0004          /* freezestr */
#define SQ_WRITER       0x0008          /* qwriter(OUTER) pending or running */
#define SQ_MESSAGES     0x0010          /* messages on syncq */
#define SQ_WANTWAKEUP   0x0020          /* do cv_broadcast on sq_wait */
#define SQ_WANTEXWAKEUP 0x0040          /* do cv_broadcast on sq_exitwait */
#define SQ_EVENTS       0x0080          /* Events pending */
#define SQ_QUEUED       (SQ_MESSAGES | SQ_EVENTS)
#define SQ_FLAGMASK     0x00FF

/*
 * Test a queue to see if inner perimeter is exclusive.
 */
#define PERIM_EXCL(q)   ((q)->q_syncq->sq_flags & SQ_EXCL)

/*
 * If any of these flags are set it is not possible for a thread to
 * enter a put or service procedure. Instead it must either block
 * or put the message on the syncq.
 */
#define SQ_GOAWAY       (SQ_EXCL|SQ_BLOCKED|SQ_FROZEN|SQ_WRITER|\
                        SQ_QUEUED)
/*
 * If any of these flags are set it not possible to drain the syncq
 */
#define SQ_STAYAWAY     (SQ_BLOCKED|SQ_FROZEN|SQ_WRITER)

/*
 * Flags to trigger syncq tail processing.
 */
#define SQ_TAIL         (SQ_QUEUED|SQ_WANTWAKEUP|SQ_WANTEXWAKEUP)

/*
 * Syncq types (stored in sq_type)
 * The SQ_TYPES_IN_FLAGS (ciput) are also stored in sq_flags
 * for performance reasons. Thus these type values have to be in the low
 * 16 bits and not conflict with the sq_flags values above.
 *
 * Notes:
 *  - putnext() and put() assume that the put procedures have the highest
 *    degree of concurrency. Thus if any of the SQ_CI* are set then SQ_CIPUT
 *    has to be set. This restriction can be lifted by adding code to putnext
 *    and put that check that sq_count == 0 like entersq does.
 *  - putnext() and put() does currently not handle !SQ_COPUT
 *  - In order to implement !SQ_COCB outer_enter has to be fixed so that
 *    the callback can be cancelled while cv_waiting in outer_enter.
 *  - If SQ_CISVC needs to be implemented, qprocsoff() needs to wait
 *    for the currently running services to stop (wait for QINSERVICE
 *    to go off). disable_svc called from qprcosoff disables only
 *    services that will be run in future.
 *
 * All the SQ_CO flags are set when there is no outer perimeter.
 */
#define SQ_CIPUT        0x0100          /* Concurrent inner put proc */
#define SQ_CISVC        0x0200          /* Concurrent inner svc proc */
#define SQ_CIOC         0x0400          /* Concurrent inner open/close */
#define SQ_CICB         0x0800          /* Concurrent inner callback */
#define SQ_COPUT        0x1000          /* Concurrent outer put proc */
#define SQ_COSVC        0x2000          /* Concurrent outer svc proc */
#define SQ_COOC         0x4000          /* Concurrent outer open/close */
#define SQ_COCB         0x8000          /* Concurrent outer callback */

/* Types also kept in sq_flags for performance */
#define SQ_TYPES_IN_FLAGS       (SQ_CIPUT)

#define SQ_CI           (SQ_CIPUT|SQ_CISVC|SQ_CIOC|SQ_CICB)
#define SQ_CO           (SQ_COPUT|SQ_COSVC|SQ_COOC|SQ_COCB)
#define SQ_TYPEMASK     (SQ_CI|SQ_CO)

/*
 * Flag combinations passed to entersq and leavesq to specify the type
 * of entry point.
 */
#define SQ_PUT          (SQ_CIPUT|SQ_COPUT)
#define SQ_SVC          (SQ_CISVC|SQ_COSVC)
#define SQ_OPENCLOSE    (SQ_CIOC|SQ_COOC)
#define SQ_CALLBACK     (SQ_CICB|SQ_COCB)

/*
 * Other syncq types which are not copied into flags.
 */
#define SQ_PERMOD       0x01            /* Syncq is PERMOD */

/*
 * Asynchronous callback qun*** flag.
 * The mechanism these flags are used in is one where callbacks enter
 * the perimeter thanks to framework support. To use this mechanism
 * the q* and qun* flavors of the callback routines must be used.
 * e.g. qtimeout and quntimeout. The synchronization provided by the flags
 * avoids deadlocks between blocking qun* routines and the perimeter
 * lock.
 */
#define SQ_CALLB_BYPASSED       0x01            /* bypassed callback fn */

/*
 * Cancel callback mask.
 * The mask expands as the number of cancelable callback types grows
 * Note - separate callback flag because different callbacks have
 * overlapping id space.
 */
#define SQ_CALLB_CANCEL_MASK    (SQ_CANCEL_TOUT|SQ_CANCEL_BUFCALL)

#define SQ_CANCEL_TOUT          0x02            /* cancel timeout request */
#define SQ_CANCEL_BUFCALL       0x04            /* cancel bufcall request */

typedef struct callbparams {
        syncq_t         *cbp_sq;
        void            (*cbp_func)(void *);
        void            *cbp_arg;
        callbparams_id_t cbp_id;
        uint_t          cbp_flags;
        struct callbparams *cbp_next;
        size_t          cbp_size;
} callbparams_t;

typedef struct strbufcall {
        void            (*bc_func)(void *);
        void            *bc_arg;
        size_t          bc_size;
        bufcall_id_t    bc_id;
        struct strbufcall *bc_next;
        kthread_id_t    bc_executor;
} strbufcall_t;

/*
 * Structure of list of processes to be sent SIGPOLL/SIGURG signal
 * on request.  The valid S_* events are defined in stropts.h.
 */
typedef struct strsig {
        struct pid      *ss_pidp;       /* pid/pgrp pointer */
        pid_t           ss_pid;         /* positive pid, negative pgrp */
        int             ss_events;      /* S_* events */
        struct strsig   *ss_next;
} strsig_t;

/*
 * bufcall list
 */
struct bclist {
        strbufcall_t    *bc_head;
        strbufcall_t    *bc_tail;
};

/*
 * Structure used to track mux links and unlinks.
 */
struct mux_node {
        major_t          mn_imaj;       /* internal major device number */
        uint16_t         mn_indegree;   /* number of incoming edges */
        struct mux_node *mn_originp;    /* where we came from during search */
        struct mux_edge *mn_startp;     /* where search left off in mn_outp */
        struct mux_edge *mn_outp;       /* list of outgoing edges */
        uint_t           mn_flags;      /* see below */
};

/*
 * Flags for mux_nodes.
 */
#define VISITED 1

/*
 * Edge structure - a list of these is hung off the
 * mux_node to represent the outgoing edges.
 */
struct mux_edge {
        struct mux_node *me_nodep;      /* edge leads to this node */
        struct mux_edge *me_nextp;      /* next edge */
        int              me_muxid;      /* id of link */
        dev_t            me_dev;        /* dev_t - used for kernel PUNLINK */
};

/*
 * Queue info
 *
 * The syncq is included here to reduce memory fragmentation
 * for kernel memory allocators that only allocate in sizes that are
 * powers of two. If the kernel memory allocator changes this should
 * be revisited.
 */
typedef struct queinfo {
        struct queue    qu_rqueue;      /* read queue - must be first */
        struct queue    qu_wqueue;      /* write queue - must be second */
        struct syncq    qu_syncq;       /* syncq - must be third */
} queinfo_t;

/*
 * Multiplexed streams info
 */
typedef struct linkinfo {
        struct linkblk  li_lblk;        /* must be first */
        struct file     *li_fpdown;     /* file pointer for lower stream */
        struct linkinfo *li_next;       /* next in list */
        struct linkinfo *li_prev;       /* previous in list */
} linkinfo_t;

/*
 * List of syncq's used by freeezestr/unfreezestr
 */
typedef struct syncql {
        struct syncql   *sql_next;
        syncq_t         *sql_sq;
} syncql_t;

typedef struct sqlist {
        syncql_t        *sqlist_head;
        size_t          sqlist_size;            /* structure size in bytes */
        size_t          sqlist_index;           /* next free entry in array */
        syncql_t        sqlist_array[4];        /* 4 or more entries */
} sqlist_t;

typedef struct perdm {
        struct perdm            *dm_next;
        syncq_t                 *dm_sq;
        struct streamtab        *dm_str;
        uint_t                  dm_ref;
} perdm_t;

#define NEED_DM(dmp, qflag) \
        (dmp == NULL && (qflag & (QPERMOD | QMTOUTPERIM)))

/*
 * fmodsw_impl_t is used within the kernel. fmodsw is used by
 * the modules/drivers. The information is copied from fmodsw
 * defined in the module/driver into the fmodsw_impl_t structure
 * during the module/driver initialization.
 */
typedef struct fmodsw_impl      fmodsw_impl_t;

struct fmodsw_impl {
        fmodsw_impl_t           *f_next;
        char                    f_name[FMNAMESZ + 1];
        struct streamtab        *f_str;
        uint32_t                f_qflag;
        uint32_t                f_sqtype;
        perdm_t                 *f_dmp;
        uint32_t                f_ref;
        uint32_t                f_hits;
};

typedef enum {
        FMODSW_HOLD =   0x00000001,
        FMODSW_LOAD =   0x00000002
} fmodsw_flags_t;

typedef struct cdevsw_impl {
        struct streamtab        *d_str;
        uint32_t                d_qflag;
        uint32_t                d_sqtype;
        perdm_t                 *d_dmp;
} cdevsw_impl_t;

/*
 * Enumeration of the types of access that can be requested for a
 * controlling terminal under job control.
 */
enum jcaccess {
        JCREAD,                 /* read data on a ctty */
        JCWRITE,                /* write data to a ctty */
        JCSETP,                 /* set ctty parameters */
        JCGETP                  /* get ctty parameters */
};

struct str_stack {
        netstack_t      *ss_netstack;   /* Common netstack */

        kmutex_t        ss_sad_lock;    /* autopush lock */
        mod_hash_t      *ss_sad_hash;
        size_t          ss_sad_hash_nchains;
        struct saddev   *ss_saddev;     /* sad device array */
        int             ss_sadcnt;      /* number of sad devices */

        int             ss_devcnt;      /* number of mux_nodes */
        struct mux_node *ss_mux_nodes;  /* mux info for cycle checking */
};
typedef struct str_stack str_stack_t;

/*
 * Finding related queues
 */
#define STREAM(q)       ((q)->q_stream)
#define SQ(rq)          ((syncq_t *)((rq) + 2))

/*
 * Get the module/driver name for a queue.  Since some queues don't have
 * q_info structures (e.g., see log_makeq()), fall back to "?".
 */
#define Q2NAME(q) \
        (((q)->q_qinfo != NULL && (q)->q_qinfo->qi_minfo->mi_idname != NULL) ? \
        (q)->q_qinfo->qi_minfo->mi_idname : "?")

/*
 * Locking macros
 */
#define QLOCK(q)        (&(q)->q_lock)
#define SQLOCK(sq)      (&(sq)->sq_lock)

#define STREAM_PUTLOCKS_ENTER(stp) {                                           \
                ASSERT(MUTEX_HELD(&(stp)->sd_lock));                           \
                if ((stp)->sd_ciputctrl != NULL) {                             \
                        int i;                                                 \
                        int nlocks = (stp)->sd_nciputctrl;                     \
                        ciputctrl_t *cip = (stp)->sd_ciputctrl;                \
                        for (i = 0; i <= nlocks; i++) {                        \
                                mutex_enter(&cip[i].ciputctrl_lock);           \
                        }                                                      \
                }                                                              \
        }

#define STREAM_PUTLOCKS_EXIT(stp) {                                            \
                ASSERT(MUTEX_HELD(&(stp)->sd_lock));                           \
                if ((stp)->sd_ciputctrl != NULL) {                             \
                        int i;                                                 \
                        int nlocks = (stp)->sd_nciputctrl;                     \
                        ciputctrl_t *cip = (stp)->sd_ciputctrl;                \
                        for (i = 0; i <= nlocks; i++) {                        \
                                mutex_exit(&cip[i].ciputctrl_lock);            \
                        }                                                      \
                }                                                              \
        }

#define SQ_PUTLOCKS_ENTER(sq) {                                                \
                ASSERT(MUTEX_HELD(SQLOCK(sq)));                                \
                if ((sq)->sq_ciputctrl != NULL) {                              \
                        int i;                                                 \
                        int nlocks = (sq)->sq_nciputctrl;                      \
                        ciputctrl_t *cip = (sq)->sq_ciputctrl;                 \
                        ASSERT((sq)->sq_type & SQ_CIPUT);                      \
                        for (i = 0; i <= nlocks; i++) {                        \
                                mutex_enter(&cip[i].ciputctrl_lock);           \
                        }                                                      \
                }                                                              \
        }

#define SQ_PUTLOCKS_EXIT(sq) {                                                 \
                ASSERT(MUTEX_HELD(SQLOCK(sq)));                                \
                if ((sq)->sq_ciputctrl != NULL) {                              \
                        int i;                                                 \
                        int nlocks = (sq)->sq_nciputctrl;                      \
                        ciputctrl_t *cip = (sq)->sq_ciputctrl;                 \
                        ASSERT((sq)->sq_type & SQ_CIPUT);                      \
                        for (i = 0; i <= nlocks; i++) {                        \
                                mutex_exit(&cip[i].ciputctrl_lock);            \
                        }                                                      \
                }                                                              \
        }

#define SQ_PUTCOUNT_SETFAST(sq) {                                       \
                ASSERT(MUTEX_HELD(SQLOCK(sq)));                         \
                if ((sq)->sq_ciputctrl != NULL) {                       \
                        int i;                                          \
                        int nlocks = (sq)->sq_nciputctrl;               \
                        ciputctrl_t *cip = (sq)->sq_ciputctrl;          \
                        ASSERT((sq)->sq_type & SQ_CIPUT);               \
                        for (i = 0; i <= nlocks; i++) {                 \
                                mutex_enter(&cip[i].ciputctrl_lock);    \
                                cip[i].ciputctrl_count |= SQ_FASTPUT;   \
                                mutex_exit(&cip[i].ciputctrl_lock);     \
                        }                                               \
                }                                                       \
        }

#define SQ_PUTCOUNT_CLRFAST(sq) {                                       \
                ASSERT(MUTEX_HELD(SQLOCK(sq)));                         \
                if ((sq)->sq_ciputctrl != NULL) {                       \
                        int i;                                          \
                        int nlocks = (sq)->sq_nciputctrl;               \
                        ciputctrl_t *cip = (sq)->sq_ciputctrl;          \
                        ASSERT((sq)->sq_type & SQ_CIPUT);               \
                        for (i = 0; i <= nlocks; i++) {                 \
                                mutex_enter(&cip[i].ciputctrl_lock);    \
                                cip[i].ciputctrl_count &= ~SQ_FASTPUT;  \
                                mutex_exit(&cip[i].ciputctrl_lock);     \
                        }                                               \
                }                                                       \
        }


#ifdef  DEBUG

#define SQ_PUTLOCKS_HELD(sq) {                                                 \
                ASSERT(MUTEX_HELD(SQLOCK(sq)));                                \
                if ((sq)->sq_ciputctrl != NULL) {                              \
                        int i;                                                 \
                        int nlocks = (sq)->sq_nciputctrl;                      \
                        ciputctrl_t *cip = (sq)->sq_ciputctrl;                 \
                        ASSERT((sq)->sq_type & SQ_CIPUT);                      \
                        for (i = 0; i <= nlocks; i++) {                        \
                                ASSERT(MUTEX_HELD(&cip[i].ciputctrl_lock));    \
                        }                                                      \
                }                                                              \
        }

#define SUMCHECK_SQ_PUTCOUNTS(sq, countcheck) {                                \
                if ((sq)->sq_ciputctrl != NULL) {                              \
                        int i;                                                 \
                        uint_t count = 0;                                      \
                        int ncounts = (sq)->sq_nciputctrl;                     \
                        ASSERT((sq)->sq_type & SQ_CIPUT);                      \
                        for (i = 0; i <= ncounts; i++) {                       \
                                count +=                                       \
                                    (((sq)->sq_ciputctrl[i].ciputctrl_count) & \
                                    SQ_FASTMASK);                              \
                        }                                                      \
                        ASSERT(count == (countcheck));                         \
                }                                                              \
        }

#define SUMCHECK_CIPUTCTRL_COUNTS(ciput, nciput, countcheck) {                 \
                int i;                                                         \
                uint_t count = 0;                                              \
                ASSERT((ciput) != NULL);                                       \
                for (i = 0; i <= (nciput); i++) {                              \
                        count += (((ciput)[i].ciputctrl_count) &               \
                            SQ_FASTMASK);                                      \
                }                                                              \
                ASSERT(count == (countcheck));                                 \
        }

#else   /* DEBUG */

#define SQ_PUTLOCKS_HELD(sq)
#define SUMCHECK_SQ_PUTCOUNTS(sq, countcheck)
#define SUMCHECK_CIPUTCTRL_COUNTS(sq, nciput, countcheck)

#endif  /* DEBUG */

#define SUM_SQ_PUTCOUNTS(sq, count) {                                          \
                if ((sq)->sq_ciputctrl != NULL) {                              \
                        int i;                                                 \
                        int ncounts = (sq)->sq_nciputctrl;                     \
                        ciputctrl_t *cip = (sq)->sq_ciputctrl;                 \
                        ASSERT((sq)->sq_type & SQ_CIPUT);                      \
                        for (i = 0; i <= ncounts; i++) {                       \
                                (count) += ((cip[i].ciputctrl_count) &         \
                                    SQ_FASTMASK);                              \
                        }                                                      \
                }                                                              \
        }

#define CLAIM_QNEXT_LOCK(stp)   mutex_enter(&(stp)->sd_lock)
#define RELEASE_QNEXT_LOCK(stp) mutex_exit(&(stp)->sd_lock)

/*
 * syncq message manipulation macros.
 */
/*
 * Put a message on the queue syncq.
 * Assumes QLOCK held.
 */
#define SQPUT_MP(qp, mp)                                                \
        {                                                               \
                qp->q_syncqmsgs++;                                      \
                if (qp->q_sqhead == NULL) {                             \
                        qp->q_sqhead = qp->q_sqtail = mp;               \
                } else {                                                \
                        qp->q_sqtail->b_next = mp;                      \
                        qp->q_sqtail = mp;                              \
                }                                                       \
                set_qfull(qp);                                          \
        }

/*
 * Miscellaneous parameters and flags.
 */

/*
 * Default timeout in milliseconds for ioctls and close
 */
#define STRTIMOUT 15000

/*
 * Flag values for stream io
 */
#define WRITEWAIT       0x1     /* waiting for write event */
#define READWAIT        0x2     /* waiting for read event */
#define NOINTR          0x4     /* error is not to be set for signal */
#define GETWAIT         0x8     /* waiting for getmsg event */

/*
 * These flags need to be unique for stream io name space
 * and copy modes name space.  These flags allow strwaitq
 * and strdoioctl to proceed as if signals or errors on the stream
 * head have not occurred; i.e. they will be detected by some other
 * means.
 * STR_NOSIG does not allow signals to interrupt the call
 * STR_NOERROR does not allow stream head read, write or hup errors to
 * affect the call.  When used with strdoioctl(), if a previous ioctl
 * is pending and times out, STR_NOERROR will cause strdoioctl() to not
 * return ETIME. If, however, the requested ioctl times out, ETIME
 * will be returned (use ic_timout instead)
 * STR_PEEK is used to inform strwaitq that the reader is peeking at data
 * and that a non-persistent error should not be cleared.
 * STR_DELAYERR is used to inform strwaitq that it should not check errors
 * after being awoken since, in addition to an error, there might also be
 * data queued on the stream head read queue.
 */
#define STR_NOSIG       0x10    /* Ignore signals during strdoioctl/strwaitq */
#define STR_NOERROR     0x20    /* Ignore errors during strdoioctl/strwaitq */
#define STR_PEEK        0x40    /* Peeking behavior on non-persistent errors */
#define STR_DELAYERR    0x80    /* Do not check errors on return */

/*
 * Copy modes for tty and I_STR ioctls
 */
#define U_TO_K  01                      /* User to Kernel */
#define K_TO_K  02                      /* Kernel to Kernel */

/*
 * Mux defines.
 */
#define LINKNORMAL      0x01            /* normal mux link */
#define LINKPERSIST     0x02            /* persistent mux link */
#define LINKTYPEMASK    0x03            /* bitmask of all link types */
#define LINKCLOSE       0x04            /* unlink from strclose */

/*
 * Definitions of Streams macros and function interfaces.
 */

/*
 * Obsolete queue scheduling macros. They are not used anymore, but still kept
 * here for 3-d party modules and drivers who might still use them.
 */
#define setqsched()
#define qready()        1

#ifdef _KERNEL
#define runqueues()
#define queuerun()
#endif

/* compatibility module for style 2 drivers with DR race condition */
#define DRMODNAME       "drcompat"

/*
 * Macros dealing with mux_nodes.
 */
#define MUX_VISIT(X)    ((X)->mn_flags |= VISITED)
#define MUX_CLEAR(X)    ((X)->mn_flags &= (~VISITED)); \
                        ((X)->mn_originp = NULL)
#define MUX_DIDVISIT(X) ((X)->mn_flags & VISITED)


/*
 * Twisted stream macros
 */
#define STRMATED(X)     ((X)->sd_flag & STRMATE)
#define STRLOCKMATES(X) if (&((X)->sd_lock) > &(((X)->sd_mate)->sd_lock)) { \
                                mutex_enter(&((X)->sd_lock)); \
                                mutex_enter(&(((X)->sd_mate)->sd_lock));  \
                        } else {  \
                                mutex_enter(&(((X)->sd_mate)->sd_lock)); \
                                mutex_enter(&((X)->sd_lock)); \
                        }
#define STRUNLOCKMATES(X)       mutex_exit(&((X)->sd_lock)); \
                        mutex_exit(&(((X)->sd_mate)->sd_lock))

#ifdef _KERNEL

extern void strinit(void);
extern int strdoioctl(struct stdata *, struct strioctl *, int, int,
    cred_t *, int *);
extern void strsendsig(struct strsig *, int, uchar_t, int);
extern void str_sendsig(vnode_t *, int, uchar_t, int);
extern void strhup(struct stdata *);
extern int qattach(queue_t *, dev_t *, int, cred_t *, fmodsw_impl_t *,
    boolean_t);
extern int qreopen(queue_t *, dev_t *, int, cred_t *);
extern void qdetach(queue_t *, int, int, cred_t *, boolean_t);
extern void enterq(queue_t *);
extern void leaveq(queue_t *);
extern int putiocd(mblk_t *, caddr_t, int, cred_t *);
extern int getiocd(mblk_t *, caddr_t, int);
extern struct linkinfo *alloclink(queue_t *, queue_t *, struct file *);
extern void lbfree(struct linkinfo *);
extern int linkcycle(stdata_t *, stdata_t *, str_stack_t *);
extern struct linkinfo *findlinks(stdata_t *, int, int, str_stack_t *);
extern queue_t *getendq(queue_t *);
extern int mlink(vnode_t *, int, int, cred_t *, int *, int);
extern int mlink_file(vnode_t *, int, struct file *, cred_t *, int *, int);
extern int munlink(struct stdata *, struct linkinfo *, int, cred_t *, int *,
    str_stack_t *);
extern int munlinkall(struct stdata *, int, cred_t *, int *, str_stack_t *);
extern void mux_addedge(stdata_t *, stdata_t *, int, str_stack_t *);
extern void mux_rmvedge(stdata_t *, int, str_stack_t *);
extern int devflg_to_qflag(struct streamtab *, uint32_t, uint32_t *,
    uint32_t *);
extern void setq(queue_t *, struct qinit *, struct qinit *, perdm_t *,
    uint32_t, uint32_t, boolean_t);
extern perdm_t *hold_dm(struct streamtab *, uint32_t, uint32_t);
extern void rele_dm(perdm_t *);
extern int strmakectl(struct strbuf *, int32_t, int32_t, mblk_t **);
extern int strmakedata(ssize_t *, struct uio *, stdata_t *, int32_t, mblk_t **);
extern int strmakemsg(struct strbuf *, ssize_t *, struct uio *,
    struct stdata *, int32_t, mblk_t **);
extern int strgetmsg(vnode_t *, struct strbuf *, struct strbuf *, uchar_t *,
    int *, int, rval_t *);
extern int strputmsg(vnode_t *, struct strbuf *, struct strbuf *, uchar_t,
    int flag, int fmode);
extern int strstartplumb(struct stdata *, int, int);
extern void strendplumb(struct stdata *);
extern int stropen(struct vnode *, dev_t *, int, cred_t *);
extern int strclose(struct vnode *, int, cred_t *);
extern int strpoll(register struct stdata *, short, int, short *,
    struct pollhead **);
extern void strclean(struct vnode *);
extern void str_cn_clean();     /* XXX hook for consoles signal cleanup */
extern int strwrite(struct vnode *, struct uio *, cred_t *);
extern int strwrite_common(struct vnode *, struct uio *, cred_t *, int);
extern int strread(struct vnode *, struct uio *, cred_t *);
extern int strioctl(struct vnode *, int, intptr_t, int, int, cred_t *, int *);
extern int strrput(queue_t *, mblk_t *);
extern int strrput_nondata(queue_t *, mblk_t *);
extern mblk_t *strrput_proto(vnode_t *, mblk_t *,
    strwakeup_t *, strsigset_t *, strsigset_t *, strpollset_t *);
extern mblk_t *strrput_misc(vnode_t *, mblk_t *,
    strwakeup_t *, strsigset_t *, strsigset_t *, strpollset_t *);
extern int getiocseqno(void);
extern int strwaitbuf(size_t, int);
extern int strwaitq(stdata_t *, int, ssize_t, int, clock_t, int *);
extern struct stdata *shalloc(queue_t *);
extern void shfree(struct stdata *s);
extern queue_t *allocq(void);
extern void freeq(queue_t *);
extern qband_t *allocband(void);
extern void freeband(qband_t *);
extern void freebs_enqueue(mblk_t *, dblk_t *);
extern void setqback(queue_t *, unsigned char);
extern int strcopyin(void *, void *, size_t, int);
extern int strcopyout(void *, void *, size_t, int);
extern void strsignal(struct stdata *, int, int32_t);
extern clock_t str_cv_wait(kcondvar_t *, kmutex_t *, clock_t, int);
extern void disable_svc(queue_t *);
extern void enable_svc(queue_t *);
extern void remove_runlist(queue_t *);
extern void wait_svc(queue_t *);
extern void backenable(queue_t *, uchar_t);
extern void set_qend(queue_t *);
extern int strgeterr(stdata_t *, int32_t, int);
extern void qenable_locked(queue_t *);
extern mblk_t *getq_noenab(queue_t *, ssize_t);
extern void rmvq_noenab(queue_t *, mblk_t *);
extern void qbackenable(queue_t *, uchar_t);
extern void set_qfull(queue_t *);

extern void strblock(queue_t *);
extern void strunblock(queue_t *);
extern int qclaimed(queue_t *);
extern int straccess(struct stdata *, enum jcaccess);

extern void entersq(syncq_t *, int);
extern void leavesq(syncq_t *, int);
extern void claimq(queue_t *);
extern void releaseq(queue_t *);
extern void claimstr(queue_t *);
extern void releasestr(queue_t *);
extern void removeq(queue_t *);
extern void insertq(struct stdata *, queue_t *);
extern void drain_syncq(syncq_t *);
extern void qfill_syncq(syncq_t *, queue_t *, mblk_t *);
extern void qdrain_syncq(syncq_t *, queue_t *);
extern int flush_syncq(syncq_t *, queue_t *);
extern void wait_sq_svc(syncq_t *);

extern void outer_enter(syncq_t *, uint16_t);
extern void outer_exit(syncq_t *);
extern void qwriter_inner(queue_t *, mblk_t *, void (*)());
extern void qwriter_outer(queue_t *, mblk_t *, void (*)());

extern callbparams_t *callbparams_alloc(syncq_t *, void (*)(void *),
    void *, int);
extern void callbparams_free(syncq_t *, callbparams_t *);
extern void callbparams_free_id(syncq_t *, callbparams_id_t, int32_t);
extern void qcallbwrapper(void *);

extern mblk_t *esballoc_wait(unsigned char *, size_t, uint_t, frtn_t *);
extern mblk_t *esballoca(unsigned char *, size_t, uint_t, frtn_t *);
extern mblk_t *desballoca(unsigned char *, size_t, uint_t, frtn_t *);
extern int do_sendfp(struct stdata *, struct file *, struct cred *);
extern int frozenstr(queue_t *);
extern size_t xmsgsize(mblk_t *);

extern void putnext_tail(syncq_t *, queue_t *, uint32_t);
extern void stream_willservice(stdata_t *);
extern void stream_runservice(stdata_t *);

extern void strmate(vnode_t *, vnode_t *);
extern queue_t *strvp2wq(vnode_t *);
extern vnode_t *strq2vp(queue_t *);
extern mblk_t *allocb_wait(size_t, uint_t, uint_t, int *);
extern mblk_t *allocb_cred(size_t, cred_t *, pid_t);
extern mblk_t *allocb_cred_wait(size_t, uint_t, int *, cred_t *, pid_t);
extern mblk_t *allocb_tmpl(size_t, const mblk_t *);
extern mblk_t *allocb_tryhard(size_t);
extern void mblk_copycred(mblk_t *, const mblk_t *);
extern void mblk_setcred(mblk_t *, cred_t *, pid_t);
extern cred_t *msg_getcred(const mblk_t *, pid_t *);
extern cred_t *msg_extractcred(mblk_t *, pid_t *);
extern void strpollwakeup(vnode_t *, short);
extern int putnextctl_wait(queue_t *, int);

extern int kstrputmsg(struct vnode *, mblk_t *, struct uio *, ssize_t,
    unsigned char, int, int);
extern int kstrgetmsg(struct vnode *, mblk_t **, struct uio *,
    unsigned char *, int *, clock_t, rval_t *);

extern void strsetrerror(vnode_t *, int, int, errfunc_t);
extern void strsetwerror(vnode_t *, int, int, errfunc_t);
extern void strseteof(vnode_t *, int);
extern void strflushrq(vnode_t *, int);
extern void strsetrputhooks(vnode_t *, uint_t, msgfunc_t, msgfunc_t);
extern void strsetwputhooks(vnode_t *, uint_t, clock_t);
extern void strsetrwputdatahooks(vnode_t *, msgfunc_t, msgfunc_t);
extern int strwaitmark(vnode_t *);
extern void strsignal_nolock(stdata_t *, int, uchar_t);

struct multidata_s;
struct pdesc_s;
extern int hcksum_assoc(mblk_t *, struct multidata_s *, struct pdesc_s  *,
    uint32_t, uint32_t, uint32_t, uint32_t, uint32_t, int);
extern void hcksum_retrieve(mblk_t *, struct multidata_s *, struct pdesc_s *,
    uint32_t *, uint32_t *, uint32_t *, uint32_t *, uint32_t *);
extern void lso_info_set(mblk_t *, uint32_t, uint32_t);
extern void lso_info_cleanup(mblk_t *);
extern unsigned int bcksum(uchar_t *, int, unsigned int);
extern boolean_t is_vmloaned_mblk(mblk_t *, struct multidata_s *,
    struct pdesc_s *);

extern int fmodsw_register(const char *, struct streamtab *, int);
extern int fmodsw_unregister(const char *);
extern fmodsw_impl_t *fmodsw_find(const char *, fmodsw_flags_t);
extern void fmodsw_rele(fmodsw_impl_t *);

extern void freemsgchain(mblk_t *);
extern mblk_t *copymsgchain(mblk_t *);

extern mblk_t *mcopyinuio(struct stdata *, uio_t *, ssize_t, ssize_t, int *);

/*
 * shared or externally configured data structures
 */
extern ssize_t strmsgsz;                /* maximum stream message size */
extern ssize_t strctlsz;                /* maximum size of ctl message */
extern int nstrpush;                    /* maximum number of pushes allowed */

/*
 * Bufcalls related variables.
 */
extern struct bclist strbcalls;         /* List of bufcalls */
extern kmutex_t strbcall_lock;          /* Protects the list of bufcalls */
extern kcondvar_t strbcall_cv;          /* Signaling when a bufcall is added */
extern kcondvar_t bcall_cv;     /* wait of executing bufcall completes */

extern frtn_t frnop;

extern struct kmem_cache *ciputctrl_cache;
extern int n_ciputctrl;
extern int max_n_ciputctrl;
extern int min_n_ciputctrl;

extern cdevsw_impl_t *devimpl;

/*
 * esballoc queue for throttling
 */
typedef struct esb_queue {
        kmutex_t        eq_lock;
        uint_t          eq_len;         /* number of queued messages */
        mblk_t          *eq_head;       /* head of queue */
        mblk_t          *eq_tail;       /* tail of queue */
        uint_t          eq_flags;       /* esballoc queue flags */
} esb_queue_t;

/*
 * esballoc flags for queue processing.
 */
#define ESBQ_PROCESSING 0x01    /* queue is being processed */
#define ESBQ_TIMER      0x02    /* timer is active */

extern void esballoc_queue_init(void);

#endif  /* _KERNEL */

/*
 * Note: Use of these macros are restricted to kernel/unix and
 * intended for the STREAMS framework.
 * All modules/drivers should include sys/ddi.h.
 *
 * Finding related queues
 */
#define         _OTHERQ(q)      ((q)->q_flag&QREADR? (q)+1: (q)-1)
#define         _WR(q)          ((q)->q_flag&QREADR? (q)+1: (q))
#define         _RD(q)          ((q)->q_flag&QREADR? (q): (q)-1)
#define         _SAMESTR(q)     (!((q)->q_flag & QEND))

/*
 * These are also declared here for modules/drivers that erroneously
 * include strsubr.h after ddi.h or fail to include ddi.h at all.
 */
extern struct queue *OTHERQ(queue_t *); /* stream.h */
extern struct queue *RD(queue_t *);
extern struct queue *WR(queue_t *);
extern int SAMESTR(queue_t *);

/*
 * The following hardware checksum related macros are private
 * interfaces that are subject to change without notice.
 */
#ifdef _KERNEL
#define DB_CKSUMSTART(mp)       ((mp)->b_datap->db_cksumstart)
#define DB_CKSUMEND(mp)         ((mp)->b_datap->db_cksumend)
#define DB_CKSUMSTUFF(mp)       ((mp)->b_datap->db_cksumstuff)
#define DB_CKSUMFLAGS(mp)       ((mp)->b_datap->db_struioun.cksum.flags)
#define DB_CKSUM16(mp)          ((mp)->b_datap->db_cksum16)
#define DB_CKSUM32(mp)          ((mp)->b_datap->db_cksum32)
#define DB_LSOFLAGS(mp)         ((mp)->b_datap->db_struioun.cksum.flags)
#define DB_LSOMSS(mp)           ((mp)->b_datap->db_struioun.cksum.pad)
#endif  /* _KERNEL */

#ifdef  __cplusplus
}
#endif


#endif  /* _SYS_STRSUBR_H */