rf_diskqueue.h revision 1.21 
1/*	$NetBSD: rf_diskqueue.h,v 1.21 2005/12/11 12:23:37 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@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 */
56struct 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	caddr_t 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 *) */
89struct 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
104struct 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
151int rf_ConfigureDiskQueueSystem(RF_ShutdownList_t **);
152int rf_ConfigureDiskQueues(RF_ShutdownList_t **, RF_Raid_t *, RF_Config_t *);
153void rf_DiskIOEnqueue(RF_DiskQueue_t *, RF_DiskQueueData_t *, int);
154void rf_DiskIOComplete(RF_DiskQueue_t *, RF_DiskQueueData_t *, int);
155int rf_DiskIOPromote(RF_DiskQueue_t *, RF_StripeNum_t,  RF_ReconUnitNum_t);
156RF_DiskQueueData_t *rf_CreateDiskQueueData(RF_IoType_t, RF_SectorNum_t,
157					   RF_SectorCount_t , caddr_t,
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);
164void rf_FreeDiskQueueData(RF_DiskQueueData_t *);
165int 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