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rf_diskqueue.h revision 1.22
      1 /*	$NetBSD: rf_diskqueue.h,v 1.22 2007/03/04 06:02:37 christos Exp $	*/
      2 /*
      3  * Copyright (c) 1995 Carnegie-Mellon University.
      4  * All rights reserved.
      5  *
      6  * Author: Mark Holland
      7  *
      8  * Permission to use, copy, modify and distribute this software and
      9  * its documentation is hereby granted, provided that both the copyright
     10  * notice and this permission notice appear in all copies of the
     11  * software, derivative works or modified versions, and any portions
     12  * thereof, and that both notices appear in supporting documentation.
     13  *
     14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     16  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     17  *
     18  * Carnegie Mellon requests users of this software to return to
     19  *
     20  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     21  *  School of Computer Science
     22  *  Carnegie Mellon University
     23  *  Pittsburgh PA 15213-3890
     24  *
     25  * any improvements or extensions that they make and grant Carnegie the
     26  * rights to redistribute these changes.
     27  */
     28 
     29 /*****************************************************************************************
     30  *
     31  * rf_diskqueue.h -- header file for disk queues
     32  *
     33  * see comments in rf_diskqueue.c
     34  *
     35  ****************************************************************************************/
     36 
     37 
     38 #ifndef _RF__RF_DISKQUEUE_H_
     39 #define _RF__RF_DISKQUEUE_H_
     40 
     41 #include <sys/queue.h>
     42 
     43 #include <dev/raidframe/raidframevar.h>
     44 
     45 #include "rf_threadstuff.h"
     46 #include "rf_acctrace.h"
     47 #include "rf_alloclist.h"
     48 #include "rf_etimer.h"
     49 #include "rf_netbsd.h"
     50 
     51 
     52 #define RF_IO_NORMAL_PRIORITY 1
     53 #define RF_IO_LOW_PRIORITY    0
     54 
     55 /* the data held by a disk queue entry */
     56 struct RF_DiskQueueData_s {
     57 	RF_SectorNum_t sectorOffset;	/* sector offset into the disk */
     58 	RF_SectorCount_t numSector;	/* number of sectors to read/write */
     59 	RF_IoType_t type;	/* read/write/nop */
     60 	void *buf;		/* buffer pointer */
     61 	RF_StripeNum_t parityStripeID;	/* the RAID parity stripe ID this
     62 					 * access is for */
     63 	RF_ReconUnitNum_t which_ru;	/* which RU within this parity stripe */
     64 	int     priority;	/* the priority of this request */
     65 	int     (*CompleteFunc) (void *, int);	/* function to be called upon
     66 						 * completion */
     67 	void   *argument;	/* argument to be passed to CompleteFunc */
     68 	RF_Raid_t *raidPtr;	/* needed for simulation */
     69 	RF_AccTraceEntry_t *tracerec;	/* perf mon only */
     70 	RF_Etimer_t qtime;	/* perf mon only - time request is in queue */
     71 	RF_DiskQueueData_t *next;
     72 	RF_DiskQueueData_t *prev;
     73 	RF_DiskQueue_t *queue;	/* the disk queue to which this req is
     74 				 * targeted */
     75 	RF_DiskQueueDataFlags_t flags;	/* flags controlling operation */
     76 
     77 	struct proc *b_proc;	/* the b_proc from the original bp passed into
     78 				 * the driver for this I/O */
     79 	struct buf *bp;		/* a bp to use to get this I/O done */
     80 	/* TAILQ bits for a queue for completed I/O requests */
     81 	TAILQ_ENTRY(RF_DiskQueueData_s) iodone_entries;
     82 	int  error;             /* Indicate if an error occurred
     83 				   on this I/O (1=yes, 0=no) */
     84 };
     85 #define RF_LOCK_DISK_QUEUE   0x01
     86 #define RF_UNLOCK_DISK_QUEUE 0x02
     87 
     88 /* note: "Create" returns type-specific queue header pointer cast to (void *) */
     89 struct RF_DiskQueueSW_s {
     90 	RF_DiskQueueType_t queueType;
     91 	void   *(*Create) (RF_SectorCount_t, RF_AllocListElem_t *, RF_ShutdownList_t **);	/* creation routine --
     92 												 * one call per queue in
     93 												 * system */
     94 	void    (*Enqueue) (void *, RF_DiskQueueData_t *, int);	/* enqueue routine */
     95 	RF_DiskQueueData_t *(*Dequeue) (void *);	/* dequeue routine */
     96 	RF_DiskQueueData_t *(*Peek) (void *);	/* peek at head of queue */
     97 
     98 	/* the rest are optional:  they improve performance, but the driver
     99 	 * will deal with it if they don't exist */
    100 	int     (*Promote) (void *, RF_StripeNum_t, RF_ReconUnitNum_t);	/* promotes priority of
    101 									 * tagged accesses */
    102 };
    103 
    104 struct RF_DiskQueue_s {
    105 	const RF_DiskQueueSW_t *qPtr;	/* access point to queue functions */
    106 	void   *qHdr;		/* queue header, of whatever type */
    107         RF_DECLARE_MUTEX(mutex)	/* mutex locking data structures */
    108         RF_DECLARE_COND(cond)	/* condition variable for
    109 				 * synchronization */
    110 	long    numOutstanding;	/* number of I/Os currently outstanding on
    111 				 * disk */
    112 	long    maxOutstanding;	/* max # of I/Os that can be outstanding on a
    113 				 * disk (in-kernel only) */
    114 	int     curPriority;	/* the priority of accs all that are currently
    115 				 * outstanding */
    116 	long    queueLength;	/* number of requests in queue */
    117 	RF_DiskQueueData_t *nextLockingOp;	/* a locking op that has
    118 						 * arrived at the head of the
    119 						 * queue & is waiting for
    120 						 * drainage */
    121 	RF_DiskQueueFlags_t flags;	/* terminate, locked */
    122 	RF_Raid_t *raidPtr;	/* associated array */
    123 	dev_t   dev;		/* device number for kernel version */
    124 	RF_SectorNum_t last_deq_sector;	/* last sector number dequeued or
    125 					 * dispatched */
    126 	int     col;	/* debug only */
    127 	struct raidcinfo *rf_cinfo;	/* disks component info.. */
    128 };
    129 #define RF_DQ_LOCKED  0x02	/* no new accs allowed until queue is
    130 				 * explicitly unlocked */
    131 
    132 /* macros setting & returning information about queues and requests */
    133 #define RF_QUEUE_LOCKED(_q)                 ((_q)->flags & RF_DQ_LOCKED)
    134 #define RF_QUEUE_EMPTY(_q)                  (((_q)->numOutstanding == 0) && ((_q)->nextLockingOp == NULL) && !RF_QUEUE_LOCKED(_q))
    135 #define RF_QUEUE_FULL(_q)                   ((_q)->numOutstanding == (_q)->maxOutstanding)
    136 
    137 #define RF_LOCK_QUEUE(_q)                   (_q)->flags |= RF_DQ_LOCKED
    138 #define RF_UNLOCK_QUEUE(_q)                 (_q)->flags &= ~RF_DQ_LOCKED
    139 
    140 #define RF_LOCK_QUEUE_MUTEX(_q_,_wh_)   RF_LOCK_MUTEX((_q_)->mutex)
    141 #define RF_UNLOCK_QUEUE_MUTEX(_q_,_wh_) RF_UNLOCK_MUTEX((_q_)->mutex)
    142 
    143 #define RF_LOCKING_REQ(_r)                  ((_r)->flags & RF_LOCK_DISK_QUEUE)
    144 #define RF_UNLOCKING_REQ(_r)                ((_r)->flags & RF_UNLOCK_DISK_QUEUE)
    145 
    146 /* whether it is ok to dispatch a regular request */
    147 #define RF_OK_TO_DISPATCH(_q_,_r_) \
    148   (RF_QUEUE_EMPTY(_q_) || \
    149     (!RF_QUEUE_FULL(_q_) && ((_r_)->priority >= (_q_)->curPriority)))
    150 
    151 int rf_ConfigureDiskQueueSystem(RF_ShutdownList_t **);
    152 int rf_ConfigureDiskQueues(RF_ShutdownList_t **, RF_Raid_t *, RF_Config_t *);
    153 void rf_DiskIOEnqueue(RF_DiskQueue_t *, RF_DiskQueueData_t *, int);
    154 void rf_DiskIOComplete(RF_DiskQueue_t *, RF_DiskQueueData_t *, int);
    155 int rf_DiskIOPromote(RF_DiskQueue_t *, RF_StripeNum_t,  RF_ReconUnitNum_t);
    156 RF_DiskQueueData_t *rf_CreateDiskQueueData(RF_IoType_t, RF_SectorNum_t,
    157 					   RF_SectorCount_t , void *,
    158 					   RF_StripeNum_t, RF_ReconUnitNum_t,
    159 					   int (*wakeF) (void *, int),
    160 					   void *,
    161 					   RF_AccTraceEntry_t *, RF_Raid_t *,
    162 					   RF_DiskQueueDataFlags_t,
    163 					   void *, int);
    164 void rf_FreeDiskQueueData(RF_DiskQueueData_t *);
    165 int rf_ConfigureDiskQueue(RF_Raid_t *, RF_DiskQueue_t *,
    166 			  RF_RowCol_t, const RF_DiskQueueSW_t *,
    167 			  RF_SectorCount_t, dev_t, int,
    168 			  RF_ShutdownList_t **,
    169 			  RF_AllocListElem_t *);
    170 
    171 #endif				/* !_RF__RF_DISKQUEUE_H_ */
    172