drivers/block/blk.h

/* */
This source file includes following definitions.
end_request
   1 #ifndef _BLK_H
   2 #define _BLK_H
   3 
   4 #include <linux/blkdev.h>
   5 #include <linux/locks.h>
   6 
   7 /*
   8  * NR_REQUEST is the number of entries in the request-queue.
   9  * NOTE that writes may use only the low 2/3 of these: reads
  10  * take precedence.
  11  *
  12  * 32 seems to be a reasonable number: enough to get some benefit
  13  * from the elevator-mechanism, but not so much as to lock a lot of
  14  * buffers when they are in the queue. 64 seems to be too many (easily
  15  * long pauses in reading when heavy writing/syncing is going on)
  16  */
  17 #define NR_REQUEST      64
  18 
  19 /*
  20  * This is used in the elevator algorithm: Note that
  21  * reads always go before writes. This is natural: reads
  22  * are much more time-critical than writes.
  23  */
  24 #define IN_ORDER(s1,s2) \
  25 ((s1)->cmd < (s2)->cmd || ((s1)->cmd == (s2)->cmd && \
  26 ((s1)->dev < (s2)->dev || (((s1)->dev == (s2)->dev && \
  27 (s1)->sector < (s2)->sector)))))
  28 
  29 /*
  30  * These will have to be changed to be aware of different buffer
  31  * sizes etc.. It actually needs a major cleanup.
  32  */
  33 #define SECTOR_MASK (blksize_size[MAJOR_NR] &&     \
  34         blksize_size[MAJOR_NR][MINOR(CURRENT->dev)] ? \
  35         ((blksize_size[MAJOR_NR][MINOR(CURRENT->dev)] >> 9) - 1) :  \
  36         ((BLOCK_SIZE >> 9)  -  1))
  37 
  38 #define SUBSECTOR(block) (CURRENT->current_nr_sectors > 0)
  39 
  40 extern unsigned long hd_init(unsigned long mem_start, unsigned long mem_end);
  41 extern unsigned long cdu31a_init(unsigned long mem_start, unsigned long mem_end);
  42 extern unsigned long mcd_init(unsigned long mem_start, unsigned long mem_end);
  43 #ifdef CONFIG_SBPCD
  44 extern unsigned long sbpcd_init(unsigned long, unsigned long);
  45 #endif CONFIG_SBPCD
  46 extern void set_device_ro(int dev,int flag);
  47 
  48 extern void rd_load(void);
  49 extern long rd_init(long mem_start, int length);
  50 extern int ramdisk_size;
  51 
  52 extern unsigned long xd_init(unsigned long mem_start, unsigned long mem_end);
  53 
  54 #define RO_IOCTLS(dev,where) \
  55   case BLKROSET: if (!suser()) return -EACCES; \
  56                  set_device_ro((dev),get_fs_long((long *) (where))); return 0; \
  57   case BLKROGET: { int __err = verify_area(VERIFY_WRITE, (void *) (where), sizeof(long)); \
  58                    if (!__err) put_fs_long(0!=is_read_only(dev),(long *) (where)); return __err; }
  59                  
  60 #ifdef MAJOR_NR
  61 
  62 /*
  63  * Add entries as needed. Currently the only block devices
  64  * supported are hard-disks and floppies.
  65  */
  66 
  67 #if (MAJOR_NR == MEM_MAJOR)
  68 
  69 /* ram disk */
  70 #define DEVICE_NAME "ramdisk"
  71 #define DEVICE_REQUEST do_rd_request
  72 #define DEVICE_NR(device) ((device) & 7)
  73 #define DEVICE_ON(device) 
  74 #define DEVICE_OFF(device)
  75 
  76 #elif (MAJOR_NR == FLOPPY_MAJOR)
  77 
  78 static void floppy_on(unsigned int nr);
  79 static void floppy_off(unsigned int nr);
  80 
  81 #define DEVICE_NAME "floppy"
  82 #define DEVICE_INTR do_floppy
  83 #define DEVICE_REQUEST do_fd_request
  84 #define DEVICE_NR(device) ( ((device) & 3) | (((device) & 0x80 ) >> 5 ))
  85 #define DEVICE_ON(device) floppy_on(DEVICE_NR(device))
  86 #define DEVICE_OFF(device) floppy_off(DEVICE_NR(device))
  87 
  88 #elif (MAJOR_NR == HD_MAJOR)
  89 
  90 /* harddisk: timeout is 6 seconds.. */
  91 #define DEVICE_NAME "harddisk"
  92 #define DEVICE_INTR do_hd
  93 #define DEVICE_TIMEOUT HD_TIMER
  94 #define TIMEOUT_VALUE 600
  95 #define DEVICE_REQUEST do_hd_request
  96 #define DEVICE_NR(device) (MINOR(device)>>6)
  97 #define DEVICE_ON(device)
  98 #define DEVICE_OFF(device)
  99 
 100 #elif (MAJOR_NR == SCSI_DISK_MAJOR)
 101 
 102 #define DEVICE_NAME "scsidisk"
 103 #define DEVICE_INTR do_sd  
 104 #define TIMEOUT_VALUE 200
 105 #define DEVICE_REQUEST do_sd_request
 106 #define DEVICE_NR(device) (MINOR(device) >> 4)
 107 #define DEVICE_ON(device)
 108 #define DEVICE_OFF(device)
 109 
 110 #elif (MAJOR_NR == SCSI_TAPE_MAJOR)
 111 
 112 #define DEVICE_NAME "scsitape"
 113 #define DEVICE_INTR do_st  
 114 #define DEVICE_NR(device) (MINOR(device))
 115 #define DEVICE_ON(device)
 116 #define DEVICE_OFF(device)
 117 
 118 #elif (MAJOR_NR == SCSI_CDROM_MAJOR)
 119 
 120 #define DEVICE_NAME "CD-ROM"
 121 #define DEVICE_INTR do_sr
 122 #define DEVICE_REQUEST do_sr_request
 123 #define DEVICE_NR(device) (MINOR(device))
 124 #define DEVICE_ON(device)
 125 #define DEVICE_OFF(device)
 126 
 127 #elif (MAJOR_NR == XT_DISK_MAJOR)
 128 
 129 #define DEVICE_NAME "xt disk"
 130 #define DEVICE_REQUEST do_xd_request
 131 #define DEVICE_NR(device) (MINOR(device) >> 6)
 132 #define DEVICE_ON(device)
 133 #define DEVICE_OFF(device)
 134 
 135 #elif (MAJOR_NR == CDU31A_CDROM_MAJOR)
 136 
 137 #define DEVICE_NAME "CDU31A"
 138 #define DEVICE_REQUEST do_cdu31a_request
 139 #define DEVICE_NR(device) (MINOR(device))
 140 #define DEVICE_ON(device)
 141 #define DEVICE_OFF(device)
 142 
 143 #elif (MAJOR_NR == MITSUMI_CDROM_MAJOR)
 144 
 145 #define DEVICE_NAME "Mitsumi CD-ROM"
 146 /* #define DEVICE_INTR do_mcd */
 147 #define DEVICE_REQUEST do_mcd_request
 148 #define DEVICE_NR(device) (MINOR(device))
 149 #define DEVICE_ON(device)
 150 #define DEVICE_OFF(device)
 151 
 152 #elif (MAJOR_NR == MATSUSHITA_CDROM_MAJOR)
 153 
 154 #define DEVICE_NAME "Matsushita CD-ROM controller #1"
 155 #define DEVICE_REQUEST do_sbpcd_request
 156 #define DEVICE_NR(device) (MINOR(device))
 157 #define DEVICE_ON(device)
 158 #define DEVICE_OFF(device)
 159 
 160 #elif (MAJOR_NR == MATSUSHITA_CDROM2_MAJOR)
 161 
 162 #define DEVICE_NAME "Matsushita CD-ROM controller #2"
 163 #define DEVICE_REQUEST do_sbpcd2_request
 164 #define DEVICE_NR(device) (MINOR(device))
 165 #define DEVICE_ON(device)
 166 #define DEVICE_OFF(device)
 167 
 168 #elif (MAJOR_NR == MATSUSHITA_CDROM3_MAJOR)
 169 
 170 #define DEVICE_NAME "Matsushita CD-ROM controller #3"
 171 #define DEVICE_REQUEST do_sbpcd3_request
 172 #define DEVICE_NR(device) (MINOR(device))
 173 #define DEVICE_ON(device)
 174 #define DEVICE_OFF(device)
 175 
 176 #elif (MAJOR_NR == MATSUSHITA_CDROM4_MAJOR)
 177 
 178 #define DEVICE_NAME "Matsushita CD-ROM controller #4"
 179 #define DEVICE_REQUEST do_sbpcd4_request
 180 #define DEVICE_NR(device) (MINOR(device))
 181 #define DEVICE_ON(device)
 182 #define DEVICE_OFF(device)
 183 
 184 #endif
 185 
 186 #if (MAJOR_NR != SCSI_TAPE_MAJOR)
 187 
 188 #ifndef CURRENT
 189 #define CURRENT (blk_dev[MAJOR_NR].current_request)
 190 #endif
 191 
 192 #define CURRENT_DEV DEVICE_NR(CURRENT->dev)
 193 
 194 #ifdef DEVICE_INTR
 195 void (*DEVICE_INTR)(void) = NULL;
 196 #endif
 197 #ifdef DEVICE_TIMEOUT
 198 
 199 #define SET_TIMER \
 200 ((timer_table[DEVICE_TIMEOUT].expires = jiffies + TIMEOUT_VALUE), \
 201 (timer_active |= 1<<DEVICE_TIMEOUT))
 202 
 203 #define CLEAR_TIMER \
 204 timer_active &= ~(1<<DEVICE_TIMEOUT)
 205 
 206 #define SET_INTR(x) \
 207 if ((DEVICE_INTR = (x)) != NULL) \
 208         SET_TIMER; \
 209 else \
 210         CLEAR_TIMER;
 211 
 212 #else
 213 
 214 #define SET_INTR(x) (DEVICE_INTR = (x))
 215 
 216 #endif
 217 static void (DEVICE_REQUEST)(void);
 218 
 219 /* end_request() - SCSI devices have their own version */
 220 
 221 #if ! SCSI_MAJOR(MAJOR_NR)
 222 
 223 static void end_request(int uptodate)
     /*  */
 224 {
 225         struct request * req;
 226         struct buffer_head * bh;
 227 
 228         req = CURRENT;
 229         req->errors = 0;
 230         if (!uptodate) {
 231                 printk(DEVICE_NAME " I/O error\n");
 232                 printk("dev %04lX, sector %lu\n",
 233                        (unsigned long)req->dev, req->sector);
 234                 req->nr_sectors--;
 235                 req->nr_sectors &= ~SECTOR_MASK;
 236                 req->sector += (BLOCK_SIZE / 512);
 237                 req->sector &= ~SECTOR_MASK;            
 238         }
 239 
 240         if ((bh = req->bh) != NULL) {
 241                 req->bh = bh->b_reqnext;
 242                 bh->b_reqnext = NULL;
 243                 bh->b_uptodate = uptodate;              
 244                 if (!uptodate) bh->b_req = 0; /* So no "Weird" errors */
 245                 unlock_buffer(bh);
 246                 if ((bh = req->bh) != NULL) {
 247                         req->current_nr_sectors = bh->b_size >> 9;
 248                         if (req->nr_sectors < req->current_nr_sectors) {
 249                                 req->nr_sectors = req->current_nr_sectors;
 250                                 printk("end_request: buffer-list destroyed\n");
 251                         }
 252                         req->buffer = bh->b_data;
 253                         return;
 254                 }
 255         }
 256         DEVICE_OFF(req->dev);
 257         CURRENT = req->next;
 258         if (req->sem != NULL)
 259                 up(req->sem);
 260         req->dev = -1;
 261         wake_up(&wait_for_request);
 262 }
 263 #endif
 264 
 265 #ifdef DEVICE_INTR
 266 #define CLEAR_INTR SET_INTR(NULL)
 267 #else
 268 #define CLEAR_INTR
 269 #endif
 270 
 271 #define INIT_REQUEST \
 272         if (!CURRENT) {\
 273                 CLEAR_INTR; \
 274                 return; \
 275         } \
 276         if (MAJOR(CURRENT->dev) != MAJOR_NR) \
 277                 panic(DEVICE_NAME ": request list destroyed"); \
 278         if (CURRENT->bh) { \
 279                 if (!CURRENT->bh->b_lock) \
 280                         panic(DEVICE_NAME ": block not locked"); \
 281         }
 282 
 283 #endif
 284 
 285 #endif
 286 #endif
/* */
root/drivers/block/blk.h

INCLUDED FROM

DEFINITIONS
