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Annotation of Gnu-Mach/linux/dev/drivers/scsi/sd.c, revision 1.1

1.1     ! root        1: /*
        !             2:  *      sd.c Copyright (C) 1992 Drew Eckhardt 
        !             3:  *           Copyright (C) 1993, 1994, 1995 Eric Youngdale
        !             4:  *
        !             5:  *      Linux scsi disk driver
        !             6:  *              Initial versions: Drew Eckhardt 
        !             7:  *              Subsequent revisions: Eric Youngdale
        !             8:  *
        !             9:  *      <[email protected]>
        !            10:  *
        !            11:  *       Modified by Eric Youngdale [email protected] to
        !            12:  *       add scatter-gather, multiple outstanding request, and other
        !            13:  *       enhancements.
        !            14:  *
        !            15:  *       Modified by Eric Youngdale [email protected] to support loadable
        !            16:  *       low-level scsi drivers.
        !            17:  */
        !            18: 
        !            19: #include <linux/module.h>
        !            20: #ifdef MODULE
        !            21: /*
        !            22:  * This is a variable in scsi.c that is set when we are processing something
        !            23:  * after boot time.  By definition, this is true when we are a loadable module
        !            24:  * ourselves.
        !            25:  */
        !            26: #define MODULE_FLAG 1
        !            27: #else
        !            28: #define MODULE_FLAG scsi_loadable_module_flag
        !            29: #endif /* MODULE */
        !            30: 
        !            31: #include <linux/fs.h>
        !            32: #include <linux/kernel.h>
        !            33: #include <linux/sched.h>
        !            34: #include <linux/mm.h>
        !            35: #include <linux/string.h>
        !            36: #include <linux/errno.h>
        !            37: #include <linux/interrupt.h>
        !            38: 
        !            39: #include <asm/system.h>
        !            40: 
        !            41: #define MAJOR_NR SCSI_DISK_MAJOR
        !            42: #include <linux/blk.h>
        !            43: #include "scsi.h"
        !            44: #include "hosts.h"
        !            45: #include "sd.h"
        !            46: #include <scsi/scsi_ioctl.h>
        !            47: #include "constants.h"
        !            48: 
        !            49: #include <linux/genhd.h>
        !            50: 
        !            51: /*
        !            52:  *  static const char RCSid[] = "$Header:";
        !            53:  */
        !            54: 
        !            55: #define MAX_RETRIES 5
        !            56: 
        !            57: /*
        !            58:  *  Time out in seconds for disks and Magneto-opticals (which are slower).
        !            59:  */
        !            60: 
        !            61: #define SD_TIMEOUT (20 * HZ)
        !            62: #define SD_MOD_TIMEOUT (25 * HZ)
        !            63: 
        !            64: #define CLUSTERABLE_DEVICE(SC) (SC->host->use_clustering && \
        !            65:                                SC->device->type != TYPE_MOD)
        !            66: 
        !            67: struct hd_struct * sd;
        !            68: 
        !            69: Scsi_Disk * rscsi_disks = NULL;
        !            70: static int * sd_sizes;
        !            71: static int * sd_blocksizes;
        !            72: static int * sd_hardsizes;              /* Hardware sector size */
        !            73: 
        !            74: extern int sd_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
        !            75: 
        !            76: static int check_scsidisk_media_change(kdev_t);
        !            77: static int fop_revalidate_scsidisk(kdev_t);
        !            78: 
        !            79: static int sd_init_onedisk(int);
        !            80: 
        !            81: static void requeue_sd_request (Scsi_Cmnd * SCpnt);
        !            82: 
        !            83: static int sd_init(void);
        !            84: static void sd_finish(void);
        !            85: static int sd_attach(Scsi_Device *);
        !            86: static int sd_detect(Scsi_Device *);
        !            87: static void sd_detach(Scsi_Device *);
        !            88: 
        !            89: struct Scsi_Device_Template sd_template = 
        !            90: { NULL, "disk", "sd", NULL, TYPE_DISK, 
        !            91:       SCSI_DISK_MAJOR, 0, 0, 0, 1,
        !            92:       sd_detect, sd_init,
        !            93:       sd_finish, sd_attach, sd_detach
        !            94: };
        !            95: 
        !            96: static int sd_open(struct inode * inode, struct file * filp)
        !            97: {
        !            98:     int target;
        !            99:     target =  DEVICE_NR(inode->i_rdev);
        !           100:     
        !           101:     if(target >= sd_template.dev_max || !rscsi_disks[target].device)
        !           102:        return -ENXIO;   /* No such device */
        !           103:     
        !           104:     /* 
        !           105:      * Make sure that only one process can do a check_change_disk at one time.
        !           106:      * This is also used to lock out further access when the partition table 
        !           107:      * is being re-read. 
        !           108:      */
        !           109:     
        !           110:     while (rscsi_disks[target].device->busy)
        !           111:         barrier();   
        !           112:     if(rscsi_disks[target].device->removable) {
        !           113:        check_disk_change(inode->i_rdev);
        !           114:        
        !           115:        /*
        !           116:         * If the drive is empty, just let the open fail.
        !           117:         */
        !           118:        if ( !rscsi_disks[target].ready )
        !           119:            return -ENXIO;
        !           120: 
        !           121:        /*
        !           122:         * Similarly, if the device has the write protect tab set,
        !           123:         * have the open fail if the user expects to be able to write
        !           124:         * to the thing.
        !           125:         */
        !           126:        if ( (rscsi_disks[target].write_prot) && (filp->f_mode & 2) )
        !           127:            return -EROFS;
        !           128:     }
        !           129: 
        !           130:     /*
        !           131:      * See if we are requesting a non-existent partition.  Do this
        !           132:      * after checking for disk change.
        !           133:      */
        !           134:     if(sd_sizes[MINOR(inode->i_rdev)] == 0)
        !           135:        return -ENXIO;
        !           136:     
        !           137:     if(rscsi_disks[target].device->removable)
        !           138:        if(!rscsi_disks[target].device->access_count)
        !           139:            sd_ioctl(inode, NULL, SCSI_IOCTL_DOORLOCK, 0);
        !           140: 
        !           141:     rscsi_disks[target].device->access_count++;
        !           142:     if (rscsi_disks[target].device->host->hostt->usage_count)
        !           143:        (*rscsi_disks[target].device->host->hostt->usage_count)++;
        !           144:     if(sd_template.usage_count) (*sd_template.usage_count)++;
        !           145:     return 0;
        !           146: }
        !           147: 
        !           148: static void sd_release(struct inode * inode, struct file * file)
        !           149: {
        !           150:     int target;
        !           151:     fsync_dev(inode->i_rdev);
        !           152:     
        !           153:     target =  DEVICE_NR(inode->i_rdev);
        !           154:     
        !           155:     rscsi_disks[target].device->access_count--;
        !           156:     if (rscsi_disks[target].device->host->hostt->usage_count)
        !           157:        (*rscsi_disks[target].device->host->hostt->usage_count)--;
        !           158:     if(sd_template.usage_count) (*sd_template.usage_count)--;
        !           159:     
        !           160:     if(rscsi_disks[target].device->removable) {
        !           161:        if(!rscsi_disks[target].device->access_count)
        !           162:            sd_ioctl(inode, NULL, SCSI_IOCTL_DOORUNLOCK, 0);
        !           163:     }
        !           164: }
        !           165: 
        !           166: static void sd_geninit(struct gendisk *);
        !           167: 
        !           168: static struct file_operations sd_fops = {
        !           169:     NULL,                        /* lseek - default */
        !           170:     block_read,                  /* read - general block-dev read */
        !           171:     block_write,                 /* write - general block-dev write */
        !           172:     NULL,                        /* readdir - bad */
        !           173:     NULL,                        /* select */
        !           174:     sd_ioctl,                    /* ioctl */
        !           175:     NULL,                        /* mmap */
        !           176:     sd_open,                     /* open code */
        !           177:     sd_release,                  /* release */
        !           178:     block_fsync,                 /* fsync */
        !           179:     NULL,                        /* fasync */
        !           180:     check_scsidisk_media_change, /* Disk change */
        !           181:     fop_revalidate_scsidisk      /* revalidate */
        !           182: };
        !           183: 
        !           184: static struct gendisk sd_gendisk = {
        !           185:     MAJOR_NR,                    /* Major number */
        !           186:     "sd",                        /* Major name */
        !           187:     4,                           /* Bits to shift to get real from partition */
        !           188:     1 << 4,                      /* Number of partitions per real */
        !           189:     0,                           /* maximum number of real */
        !           190:     sd_geninit,                  /* init function */
        !           191:     NULL,                        /* hd struct */
        !           192:     NULL,                        /* block sizes */
        !           193:     0,                           /* number */
        !           194:     NULL,                        /* internal */
        !           195:     NULL                         /* next */
        !           196: };
        !           197: 
        !           198: static void sd_geninit (struct gendisk *ignored)
        !           199: {
        !           200:     int i;
        !           201:     
        !           202:     for (i = 0; i < sd_template.dev_max; ++i)
        !           203:        if(rscsi_disks[i].device) 
        !           204:            sd[i << 4].nr_sects = rscsi_disks[i].capacity;
        !           205: #if 0
        !           206:     /* No longer needed - we keep track of this as we attach/detach */
        !           207:     sd_gendisk.nr_real = sd_template.dev_max;
        !           208: #endif
        !           209: }
        !           210: 
        !           211: /*
        !           212:  * rw_intr is the interrupt routine for the device driver.
        !           213:  * It will be notified on the end of a SCSI read / write, and
        !           214:  * will take one of several actions based on success or failure.
        !           215:  */
        !           216: 
        !           217: static void rw_intr (Scsi_Cmnd *SCpnt)
        !           218: {
        !           219:     int result = SCpnt->result;
        !           220:     int this_count = SCpnt->bufflen >> 9;
        !           221:     int good_sectors = (result == 0 ? this_count : 0);
        !           222:     int block_sectors = 1;
        !           223:     
        !           224: #ifdef DEBUG
        !           225:     printk("sd%c : rw_intr(%d, %d)\n", 'a' + MINOR(SCpnt->request.rq_dev), 
        !           226:           SCpnt->host->host_no, result);
        !           227: #endif
        !           228: 
        !           229:     /*
        !           230:       Handle MEDIUM ERRORs that indicate partial success.  Since this is a
        !           231:       relatively rare error condition, no care is taken to avoid unnecessary
        !           232:       additional work such as memcpy's that could be avoided.
        !           233:     */
        !           234: 
        !           235:     if (driver_byte(result) != 0 &&                /* An error occurred */
        !           236:        SCpnt->sense_buffer[0] == 0xF0 &&           /* Sense data is valid */
        !           237:        SCpnt->sense_buffer[2] == MEDIUM_ERROR)
        !           238:       {
        !           239:        long error_sector = (SCpnt->sense_buffer[3] << 24) |
        !           240:                            (SCpnt->sense_buffer[4] << 16) |
        !           241:                            (SCpnt->sense_buffer[5] << 8) |
        !           242:                            SCpnt->sense_buffer[6];
        !           243:        int sector_size =
        !           244:          rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].sector_size;
        !           245:        if (SCpnt->request.bh != NULL)
        !           246:          block_sectors = SCpnt->request.bh->b_size >> 9;
        !           247:        if (sector_size == 1024)
        !           248:          {
        !           249:            error_sector <<= 1;
        !           250:            if (block_sectors < 2) block_sectors = 2;
        !           251:          }
        !           252:        else if (sector_size == 256)
        !           253:          error_sector >>= 1;
        !           254:        error_sector -= sd[MINOR(SCpnt->request.rq_dev)].start_sect;
        !           255:        error_sector &= ~ (block_sectors - 1);
        !           256:        good_sectors = error_sector - SCpnt->request.sector;
        !           257:        if (good_sectors < 0 || good_sectors >= this_count)
        !           258:          good_sectors = 0;
        !           259:       }
        !           260:     
        !           261:     /*
        !           262:      * Handle RECOVERED ERRORs that indicate success after recovery action
        !           263:      * by the target device.
        !           264:      */
        !           265: 
        !           266:     if (SCpnt->sense_buffer[0] == 0xF0 &&          /* Sense data is valid */
        !           267:        SCpnt->sense_buffer[2] == RECOVERED_ERROR)
        !           268:       {
        !           269:        printk("scsidisk recovered I/O error: dev %s, sector %lu, absolute sector %lu\n",
        !           270:               kdevname(SCpnt->request.rq_dev), SCpnt->request.sector, 
        !           271:               SCpnt->request.sector + sd[MINOR(SCpnt->request.rq_dev)].start_sect);
        !           272:        good_sectors = this_count;
        !           273:        result = 0;
        !           274:       }
        !           275: 
        !           276:     /*
        !           277:      * First case : we assume that the command succeeded.  One of two things 
        !           278:      * will happen here.  Either we will be finished, or there will be more
        !           279:      * sectors that we were unable to read last time.
        !           280:      */
        !           281: 
        !           282:     if (good_sectors > 0) {
        !           283:        
        !           284: #ifdef DEBUG
        !           285:        printk("sd%c : %d sectors remain.\n", 'a' + MINOR(SCpnt->request.rq_dev),
        !           286:               SCpnt->request.nr_sectors);
        !           287:        printk("use_sg is %d\n ",SCpnt->use_sg);
        !           288: #endif
        !           289:        if (SCpnt->use_sg) {
        !           290:            struct scatterlist * sgpnt;
        !           291:            int i;
        !           292:            sgpnt = (struct scatterlist *) SCpnt->buffer;
        !           293:            for(i=0; i<SCpnt->use_sg; i++) {
        !           294: #ifdef DEBUG
        !           295:                printk(":%x %x %d\n",sgpnt[i].alt_address, sgpnt[i].address, 
        !           296:                       sgpnt[i].length);
        !           297: #endif
        !           298:                if (sgpnt[i].alt_address) {
        !           299:                    if (SCpnt->request.cmd == READ)
        !           300:                        memcpy(sgpnt[i].alt_address, sgpnt[i].address, 
        !           301:                               sgpnt[i].length);
        !           302:                    scsi_free(sgpnt[i].address, sgpnt[i].length);
        !           303:                }
        !           304:            }
        !           305: 
        !           306:            /* Free list of scatter-gather pointers */
        !           307:            scsi_free(SCpnt->buffer, SCpnt->sglist_len);  
        !           308:        } else {
        !           309:            if (SCpnt->buffer != SCpnt->request.buffer) {
        !           310: #ifdef DEBUG
        !           311:                printk("nosg: %x %x %d\n",SCpnt->request.buffer, SCpnt->buffer,
        !           312:                       SCpnt->bufflen);
        !           313: #endif  
        !           314:                if (SCpnt->request.cmd == READ)
        !           315:                    memcpy(SCpnt->request.buffer, SCpnt->buffer,
        !           316:                           SCpnt->bufflen);
        !           317:                scsi_free(SCpnt->buffer, SCpnt->bufflen);
        !           318:            }
        !           319:        }
        !           320:        /*
        !           321:         * If multiple sectors are requested in one buffer, then
        !           322:         * they will have been finished off by the first command.
        !           323:         * If not, then we have a multi-buffer command.
        !           324:         */
        !           325:        if (SCpnt->request.nr_sectors > this_count)
        !           326:        {
        !           327:            SCpnt->request.errors = 0;
        !           328:            
        !           329:            if (!SCpnt->request.bh)
        !           330:            {
        !           331: #ifdef DEBUG
        !           332:                printk("sd%c : handling page request, no buffer\n",
        !           333:                       'a' + MINOR(SCpnt->request.rq_dev));
        !           334: #endif
        !           335:                /*
        !           336:                 * The SCpnt->request.nr_sectors field is always done in 
        !           337:                 * 512 byte sectors, even if this really isn't the case.
        !           338:                 */
        !           339:                panic("sd.c: linked page request (%lx %x)",
        !           340:                      SCpnt->request.sector, this_count);
        !           341:            }
        !           342:        }
        !           343:        SCpnt = end_scsi_request(SCpnt, 1, good_sectors);
        !           344:        if (result == 0)
        !           345:          {
        !           346:            requeue_sd_request(SCpnt);
        !           347:            return;
        !           348:          }
        !           349:     }
        !           350:     
        !           351:     if (good_sectors == 0) {
        !           352: 
        !           353:     /* Free up any indirection buffers we allocated for DMA purposes. */
        !           354:     if (SCpnt->use_sg) {
        !           355:        struct scatterlist * sgpnt;
        !           356:        int i;
        !           357:        sgpnt = (struct scatterlist *) SCpnt->buffer;
        !           358:        for(i=0; i<SCpnt->use_sg; i++) {
        !           359: #ifdef DEBUG
        !           360:            printk("err: %x %x %d\n",SCpnt->request.buffer, SCpnt->buffer,
        !           361:                   SCpnt->bufflen);
        !           362: #endif
        !           363:            if (sgpnt[i].alt_address) {
        !           364:                scsi_free(sgpnt[i].address, sgpnt[i].length);
        !           365:            }
        !           366:        }
        !           367:        scsi_free(SCpnt->buffer, SCpnt->sglist_len);  /* Free list of scatter-gather pointers */
        !           368:     } else {
        !           369: #ifdef DEBUG
        !           370:        printk("nosgerr: %x %x %d\n",SCpnt->request.buffer, SCpnt->buffer,
        !           371:               SCpnt->bufflen);
        !           372: #endif
        !           373:        if (SCpnt->buffer != SCpnt->request.buffer)
        !           374:            scsi_free(SCpnt->buffer, SCpnt->bufflen);
        !           375:     }
        !           376:     }
        !           377: 
        !           378:     /*
        !           379:      * Now, if we were good little boys and girls, Santa left us a request
        !           380:      * sense buffer.  We can extract information from this, so we
        !           381:      * can choose a block to remap, etc.
        !           382:      */
        !           383: 
        !           384:     if (driver_byte(result) != 0) {
        !           385:        if (suggestion(result) == SUGGEST_REMAP) {
        !           386: #ifdef REMAP
        !           387:            /*
        !           388:             * Not yet implemented.  A read will fail after being remapped,
        !           389:             * a write will call the strategy routine again.
        !           390:             */
        !           391:            if rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].remap
        !           392:            {
        !           393:                result = 0;
        !           394:            }
        !           395:            else
        !           396: #endif
        !           397:        }
        !           398:        
        !           399:        if ((SCpnt->sense_buffer[0] & 0x7f) == 0x70) {
        !           400:            if ((SCpnt->sense_buffer[2] & 0xf) == UNIT_ATTENTION) {
        !           401:                if(rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].device->removable) {
        !           402:                    /* detected disc change.  set a bit and quietly refuse
        !           403:                     * further access.
        !           404:                     */  
        !           405:                    rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].device->changed = 1;
        !           406:                    SCpnt = end_scsi_request(SCpnt, 0, this_count);
        !           407:                    requeue_sd_request(SCpnt);
        !           408:                    return;
        !           409:                }
        !           410:                 else
        !           411:                 {
        !           412:                     /*
        !           413:                      * Must have been a power glitch, or a bus reset.
        !           414:                      * Could not have been a media change, so we just retry
        !           415:                      * the request and see what happens.
        !           416:                      */
        !           417:                     requeue_sd_request(SCpnt);
        !           418:                     return;
        !           419:                 }
        !           420:            }
        !           421:        }
        !           422:        
        !           423:        
        !           424:        /* If we had an ILLEGAL REQUEST returned, then we may have
        !           425:         * performed an unsupported command.  The only thing this should be 
        !           426:         * would be a ten byte read where only a six byte read was supported.
        !           427:         * Also, on a system where READ CAPACITY failed, we have read past
        !           428:         * the end of the disk. 
        !           429:         */
        !           430: 
        !           431:        if (SCpnt->sense_buffer[2] == ILLEGAL_REQUEST) {
        !           432:            if (rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].ten) {
        !           433:                rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].ten = 0;
        !           434:                requeue_sd_request(SCpnt);
        !           435:                result = 0;
        !           436:            } else {
        !           437:                /* ???? */
        !           438:            }
        !           439:        }
        !           440: 
        !           441:        if (SCpnt->sense_buffer[2] == MEDIUM_ERROR) {
        !           442:            printk("scsi%d: MEDIUM ERROR on channel %d, id %d, lun %d, CDB: ",
        !           443:                   SCpnt->host->host_no, (int) SCpnt->channel, 
        !           444:                   (int) SCpnt->target, (int) SCpnt->lun);
        !           445:            print_command(SCpnt->cmnd);
        !           446:            print_sense("sd", SCpnt);
        !           447:            SCpnt = end_scsi_request(SCpnt, 0, block_sectors);
        !           448:            requeue_sd_request(SCpnt);
        !           449:            return;
        !           450:         }
        !           451:     }  /* driver byte != 0 */
        !           452:     if (result) {
        !           453:        printk("SCSI disk error : host %d channel %d id %d lun %d return code = %x\n",
        !           454:               rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].device->host->host_no,
        !           455:               rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].device->channel,
        !           456:           rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].device->id,
        !           457:             rscsi_disks[DEVICE_NR(SCpnt->request.rq_dev)].device->lun, result);
        !           458:        
        !           459:        if (driver_byte(result) & DRIVER_SENSE)
        !           460:            print_sense("sd", SCpnt);
        !           461:        SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.current_nr_sectors);
        !           462:        requeue_sd_request(SCpnt);
        !           463:        return;
        !           464:     }
        !           465: }
        !           466: 
        !           467: /*
        !           468:  * requeue_sd_request() is the request handler function for the sd driver.
        !           469:  * Its function in life is to take block device requests, and translate
        !           470:  * them to SCSI commands.
        !           471:  */
        !           472: 
        !           473: static void do_sd_request (void)
        !           474: {
        !           475:     Scsi_Cmnd * SCpnt = NULL;
        !           476:     Scsi_Device * SDev;
        !           477:     struct request * req = NULL;
        !           478:     unsigned long flags;
        !           479:     int flag = 0;
        !           480:     
        !           481:     save_flags(flags);
        !           482:     while (1==1){
        !           483:        cli();
        !           484:        if (CURRENT != NULL && CURRENT->rq_status == RQ_INACTIVE) {
        !           485:            restore_flags(flags);
        !           486:            return;
        !           487:        }
        !           488:        
        !           489:        INIT_SCSI_REQUEST;
        !           490:         SDev = rscsi_disks[DEVICE_NR(CURRENT->rq_dev)].device;
        !           491:         
        !           492:         /*
        !           493:          * I am not sure where the best place to do this is.  We need
        !           494:          * to hook in a place where we are likely to come if in user
        !           495:          * space.
        !           496:          */
        !           497:         if( SDev->was_reset )
        !           498:         {
        !           499:            /*
        !           500:             * We need to relock the door, but we might
        !           501:             * be in an interrupt handler.  Only do this
        !           502:             * from user space, since we do not want to
        !           503:             * sleep from an interrupt.
        !           504:             */
        !           505:            if( SDev->removable && !intr_count )
        !           506:            {
        !           507:                 scsi_ioctl(SDev, SCSI_IOCTL_DOORLOCK, 0);
        !           508:                /* scsi_ioctl may allow CURRENT to change, so start over. */
        !           509:                SDev->was_reset = 0;
        !           510:                continue;
        !           511:            }
        !           512:            SDev->was_reset = 0;
        !           513:         }
        !           514:                
        !           515:        /* We have to be careful here. allocate_device will get a free pointer,
        !           516:         * but there is no guarantee that it is queueable.  In normal usage, 
        !           517:         * we want to call this, because other types of devices may have the 
        !           518:         * host all tied up, and we want to make sure that we have at least 
        !           519:         * one request pending for this type of device. We can also come 
        !           520:         * through here while servicing an interrupt, because of the need to 
        !           521:         * start another command. If we call allocate_device more than once, 
        !           522:         * then the system can wedge if the command is not queueable. The 
        !           523:         * request_queueable function is safe because it checks to make sure 
        !           524:         * that the host is able to take another command before it returns
        !           525:         * a pointer.  
        !           526:         */
        !           527: 
        !           528:        if (flag++ == 0)
        !           529:            SCpnt = allocate_device(&CURRENT,
        !           530:                           rscsi_disks[DEVICE_NR(CURRENT->rq_dev)].device, 0); 
        !           531:        else SCpnt = NULL;
        !           532:        
        !           533:        /*
        !           534:         * The following restore_flags leads to latency problems.  FIXME.
        !           535:         * Using a "sti()" gets rid of the latency problems but causes
        !           536:         * race conditions and crashes.
        !           537:         */
        !           538:        restore_flags(flags);
        !           539: 
        !           540:        /* This is a performance enhancement. We dig down into the request 
        !           541:         * list and try to find a queueable request (i.e. device not busy, 
        !           542:         * and host able to accept another command. If we find one, then we 
        !           543:         * queue it. This can make a big difference on systems with more than 
        !           544:         * one disk drive.  We want to have the interrupts off when monkeying 
        !           545:         * with the request list, because otherwise the kernel might try to 
        !           546:         * slip in a request in between somewhere. 
        !           547:         */
        !           548: 
        !           549:        if (!SCpnt && sd_template.nr_dev > 1){
        !           550:            struct request *req1;
        !           551:            req1 = NULL;
        !           552:            cli();
        !           553:            req = CURRENT;
        !           554:            while(req){
        !           555:                SCpnt = request_queueable(req, 
        !           556:                                    rscsi_disks[DEVICE_NR(req->rq_dev)].device);
        !           557:                if(SCpnt) break;
        !           558:                req1 = req;
        !           559:                req = req->next;
        !           560:            }
        !           561:            if (SCpnt && req->rq_status == RQ_INACTIVE) {
        !           562:                if (req == CURRENT) 
        !           563:                    CURRENT = CURRENT->next;
        !           564:                else
        !           565:                    req1->next = req->next;
        !           566:            }
        !           567:            restore_flags(flags);
        !           568:        }
        !           569:        
        !           570:        if (!SCpnt) return; /* Could not find anything to do */
        !           571:        
        !           572:        /* Queue command */
        !           573:        requeue_sd_request(SCpnt);
        !           574:     }  /* While */
        !           575: }    
        !           576: 
        !           577: static void requeue_sd_request (Scsi_Cmnd * SCpnt)
        !           578: {
        !           579:     int dev, devm, block, this_count;
        !           580:     unsigned char cmd[10];
        !           581:     int bounce_size, contiguous;
        !           582:     int max_sg;
        !           583:     struct buffer_head * bh, *bhp;
        !           584:     char * buff, *bounce_buffer;
        !           585:     
        !           586:  repeat:
        !           587:     
        !           588:     if(!SCpnt || SCpnt->request.rq_status == RQ_INACTIVE) {
        !           589:        do_sd_request();
        !           590:        return;
        !           591:     }
        !           592:     
        !           593:     devm =  MINOR(SCpnt->request.rq_dev);
        !           594:     dev = DEVICE_NR(SCpnt->request.rq_dev);
        !           595: 
        !           596:     block = SCpnt->request.sector;
        !           597:     this_count = 0;
        !           598: 
        !           599: #ifdef DEBUG
        !           600:     printk("Doing sd request, dev = %d, block = %d\n", devm, block);
        !           601: #endif
        !           602:     
        !           603:     if (devm >= (sd_template.dev_max << 4) || 
        !           604:        !rscsi_disks[dev].device ||
        !           605:        block + SCpnt->request.nr_sectors > sd[devm].nr_sects)
        !           606:     {
        !           607:        SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.nr_sectors);
        !           608:        goto repeat;
        !           609:     }
        !           610:     
        !           611:     block += sd[devm].start_sect;
        !           612:     
        !           613:     if (rscsi_disks[dev].device->changed)
        !           614:     {
        !           615:        /*
        !           616:         * quietly refuse to do anything to a changed disc until the changed 
        !           617:         * bit has been reset
        !           618:         */
        !           619:        /* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
        !           620:        SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.nr_sectors);
        !           621:        goto repeat;
        !           622:     }
        !           623:     
        !           624: #ifdef DEBUG
        !           625:     printk("sd%c : real dev = /dev/sd%c, block = %d\n", 
        !           626:           'a' + devm, dev, block);
        !           627: #endif
        !           628:     
        !           629:     /*
        !           630:      * If we have a 1K hardware sectorsize, prevent access to single
        !           631:      * 512 byte sectors.  In theory we could handle this - in fact
        !           632:      * the scsi cdrom driver must be able to handle this because
        !           633:      * we typically use 1K blocksizes, and cdroms typically have
        !           634:      * 2K hardware sectorsizes.  Of course, things are simpler
        !           635:      * with the cdrom, since it is read-only.  For performance
        !           636:      * reasons, the filesystems should be able to handle this
        !           637:      * and not force the scsi disk driver to use bounce buffers
        !           638:      * for this.
        !           639:      */
        !           640:     if (rscsi_disks[dev].sector_size == 1024)
        !           641:        if((block & 1) || (SCpnt->request.nr_sectors & 1)) {
        !           642:            printk("sd.c:Bad block number requested");
        !           643:            SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.nr_sectors);
        !           644:            goto repeat;
        !           645:        }
        !           646:     
        !           647:     switch (SCpnt->request.cmd)
        !           648:     {
        !           649:     case WRITE :
        !           650:        if (!rscsi_disks[dev].device->writeable)
        !           651:        {
        !           652:            SCpnt = end_scsi_request(SCpnt, 0, SCpnt->request.nr_sectors);
        !           653:            goto repeat;
        !           654:        }
        !           655:        cmd[0] = WRITE_6;
        !           656:        break;
        !           657:     case READ :
        !           658:        cmd[0] = READ_6;
        !           659:        break;
        !           660:     default :
        !           661:        panic ("Unknown sd command %d\n", SCpnt->request.cmd);
        !           662:     }
        !           663:     
        !           664:     SCpnt->this_count = 0;
        !           665:     
        !           666:     /* If the host adapter can deal with very large scatter-gather
        !           667:      * requests, it is a waste of time to cluster 
        !           668:      */
        !           669:     contiguous = (!CLUSTERABLE_DEVICE(SCpnt) ? 0 :1);
        !           670:     bounce_buffer = NULL;
        !           671:     bounce_size = (SCpnt->request.nr_sectors << 9);
        !           672:     
        !           673:     /* First see if we need a bounce buffer for this request. If we do, make 
        !           674:      * sure that we can allocate a buffer. Do not waste space by allocating 
        !           675:      * a bounce buffer if we are straddling the 16Mb line 
        !           676:      */ 
        !           677:     if (contiguous && SCpnt->request.bh &&
        !           678:        ((long) SCpnt->request.bh->b_data) 
        !           679:        + (SCpnt->request.nr_sectors << 9) - 1 > ISA_DMA_THRESHOLD 
        !           680:        && SCpnt->host->unchecked_isa_dma) {
        !           681:        if(((long) SCpnt->request.bh->b_data) > ISA_DMA_THRESHOLD)
        !           682:            bounce_buffer = (char *) scsi_malloc(bounce_size);
        !           683:        if(!bounce_buffer) contiguous = 0;
        !           684:     }
        !           685:     
        !           686:     if(contiguous && SCpnt->request.bh && SCpnt->request.bh->b_reqnext)
        !           687:        for(bh = SCpnt->request.bh, bhp = bh->b_reqnext; bhp; bh = bhp, 
        !           688:            bhp = bhp->b_reqnext) {
        !           689:            if(!CONTIGUOUS_BUFFERS(bh,bhp)) { 
        !           690:                if(bounce_buffer) scsi_free(bounce_buffer, bounce_size);
        !           691:                contiguous = 0;
        !           692:                break;
        !           693:            } 
        !           694:        }
        !           695:     if (!SCpnt->request.bh || contiguous) {
        !           696:        
        !           697:        /* case of page request (i.e. raw device), or unlinked buffer */
        !           698:        this_count = SCpnt->request.nr_sectors;
        !           699:        buff = SCpnt->request.buffer;
        !           700:        SCpnt->use_sg = 0;
        !           701:        
        !           702:     } else if (SCpnt->host->sg_tablesize == 0 ||
        !           703:               (need_isa_buffer && dma_free_sectors <= 10)) {
        !           704:        
        !           705:        /* Case of host adapter that cannot scatter-gather.  We also
        !           706:         * come here if we are running low on DMA buffer memory.  We set
        !           707:         * a threshold higher than that we would need for this request so
        !           708:         * we leave room for other requests.  Even though we would not need
        !           709:         * it all, we need to be conservative, because if we run low enough
        !           710:         * we have no choice but to panic. 
        !           711:         */
        !           712:        if (SCpnt->host->sg_tablesize != 0 &&
        !           713:            need_isa_buffer && 
        !           714:            dma_free_sectors <= 10)
        !           715:            printk("Warning: SCSI DMA buffer space running low.  Using non scatter-gather I/O.\n");
        !           716:        
        !           717:        this_count = SCpnt->request.current_nr_sectors;
        !           718:        buff = SCpnt->request.buffer;
        !           719:        SCpnt->use_sg = 0;
        !           720:        
        !           721:     } else {
        !           722:        
        !           723:        /* Scatter-gather capable host adapter */
        !           724:        struct scatterlist * sgpnt;
        !           725:        int count, this_count_max;
        !           726:        int counted;
        !           727:        
        !           728:        bh = SCpnt->request.bh;
        !           729:        this_count = 0;
        !           730:        this_count_max = (rscsi_disks[dev].ten ? 0xffff : 0xff);
        !           731:        count = 0;
        !           732:        bhp = NULL;
        !           733:        while(bh) {
        !           734:            if ((this_count + (bh->b_size >> 9)) > this_count_max) break;
        !           735:            if(!bhp || !CONTIGUOUS_BUFFERS(bhp,bh) ||
        !           736:               !CLUSTERABLE_DEVICE(SCpnt) ||
        !           737:               (SCpnt->host->unchecked_isa_dma &&
        !           738:                ((unsigned long) bh->b_data-1) == ISA_DMA_THRESHOLD)) {
        !           739:                if (count < SCpnt->host->sg_tablesize) count++;
        !           740:                else break;
        !           741:            }
        !           742:            this_count += (bh->b_size >> 9);
        !           743:            bhp = bh;
        !           744:            bh = bh->b_reqnext;
        !           745:        }
        !           746: #if 0
        !           747:        if(SCpnt->host->unchecked_isa_dma &&
        !           748:           ((unsigned int) SCpnt->request.bh->b_data-1) == ISA_DMA_THRESHOLD) count--;
        !           749: #endif
        !           750:        SCpnt->use_sg = count;  /* Number of chains */
        !           751:        /* scsi_malloc can only allocate in chunks of 512 bytes */
        !           752:        count  = (SCpnt->use_sg * sizeof(struct scatterlist) + 511) & ~511;
        !           753: 
        !           754:        SCpnt->sglist_len = count;
        !           755:        max_sg = count / sizeof(struct scatterlist);
        !           756:        if(SCpnt->host->sg_tablesize < max_sg) 
        !           757:            max_sg = SCpnt->host->sg_tablesize;
        !           758:        sgpnt = (struct scatterlist * ) scsi_malloc(count);
        !           759:        if (!sgpnt) {
        !           760:            printk("Warning - running *really* short on DMA buffers\n");
        !           761:            SCpnt->use_sg = 0;    /* No memory left - bail out */
        !           762:            this_count = SCpnt->request.current_nr_sectors;
        !           763:            buff = SCpnt->request.buffer;
        !           764:        } else {
        !           765:            memset(sgpnt, 0, count);  /* Zero so it is easy to fill, but only
        !           766:                                       * if memory is available 
        !           767:                                       */
        !           768:            buff = (char *) sgpnt;
        !           769:            counted = 0;
        !           770:            for(count = 0, bh = SCpnt->request.bh, bhp = bh->b_reqnext;
        !           771:                count < SCpnt->use_sg && bh; 
        !           772:                count++, bh = bhp) {
        !           773:                
        !           774:                bhp = bh->b_reqnext;
        !           775:                
        !           776:                if(!sgpnt[count].address) sgpnt[count].address = bh->b_data;
        !           777:                sgpnt[count].length += bh->b_size;
        !           778:                counted += bh->b_size >> 9;
        !           779:                
        !           780:                if (((long) sgpnt[count].address) + sgpnt[count].length - 1 > 
        !           781:                    ISA_DMA_THRESHOLD && (SCpnt->host->unchecked_isa_dma) &&
        !           782:                    !sgpnt[count].alt_address) {
        !           783:                    sgpnt[count].alt_address = sgpnt[count].address;
        !           784:                    /* We try to avoid exhausting the DMA pool, since it is 
        !           785:                     * easier to control usage here. In other places we might 
        !           786:                     * have a more pressing need, and we would be screwed if 
        !           787:                     * we ran out */
        !           788:                    if(dma_free_sectors < (sgpnt[count].length >> 9) + 10) {
        !           789:                        sgpnt[count].address = NULL;
        !           790:                    } else {
        !           791:                        sgpnt[count].address = 
        !           792:                            (char *) scsi_malloc(sgpnt[count].length);
        !           793:                    }
        !           794:                    /* If we start running low on DMA buffers, we abort the 
        !           795:                     * scatter-gather operation, and free all of the memory 
        !           796:                     * we have allocated.  We want to ensure that all scsi 
        !           797:                     * operations are able to do at least a non-scatter/gather
        !           798:                     * operation */
        !           799:                    if(sgpnt[count].address == NULL){ /* Out of dma memory */
        !           800: #if 0
        !           801:                        printk("Warning: Running low on SCSI DMA buffers");
        !           802:                        /* Try switching back to a non s-g operation. */
        !           803:                        while(--count >= 0){
        !           804:                            if(sgpnt[count].alt_address) 
        !           805:                                scsi_free(sgpnt[count].address, 
        !           806:                                          sgpnt[count].length);
        !           807:                        }
        !           808:                        this_count = SCpnt->request.current_nr_sectors;
        !           809:                        buff = SCpnt->request.buffer;
        !           810:                        SCpnt->use_sg = 0;
        !           811:                        scsi_free(sgpnt, SCpnt->sglist_len);
        !           812: #endif
        !           813:                        SCpnt->use_sg = count;
        !           814:                        this_count = counted -= bh->b_size >> 9;
        !           815:                        break;
        !           816:                    }               
        !           817:                }
        !           818:                
        !           819:                /* Only cluster buffers if we know that we can supply DMA 
        !           820:                 * buffers large enough to satisfy the request. Do not cluster
        !           821:                 * a new request if this would mean that we suddenly need to 
        !           822:                 * start using DMA bounce buffers */
        !           823:                if(bhp && CONTIGUOUS_BUFFERS(bh,bhp) 
        !           824:                   && CLUSTERABLE_DEVICE(SCpnt)) {
        !           825:                    char * tmp;
        !           826:                    
        !           827:                    if (((long) sgpnt[count].address) + sgpnt[count].length +
        !           828:                        bhp->b_size - 1 > ISA_DMA_THRESHOLD && 
        !           829:                        (SCpnt->host->unchecked_isa_dma) &&
        !           830:                        !sgpnt[count].alt_address) continue;
        !           831:                    
        !           832:                    if(!sgpnt[count].alt_address) {count--; continue; }
        !           833:                    if(dma_free_sectors > 10)
        !           834:                        tmp = (char *) scsi_malloc(sgpnt[count].length 
        !           835:                                                   + bhp->b_size);
        !           836:                    else {
        !           837:                        tmp = NULL;
        !           838:                        max_sg = SCpnt->use_sg;
        !           839:                    }
        !           840:                    if(tmp){
        !           841:                        scsi_free(sgpnt[count].address, sgpnt[count].length);
        !           842:                        sgpnt[count].address = tmp;
        !           843:                        count--;
        !           844:                        continue;
        !           845:                    }
        !           846:                    
        !           847:                    /* If we are allowed another sg chain, then increment 
        !           848:                     * counter so we can insert it.  Otherwise we will end 
        !           849:                     up truncating */
        !           850:                    
        !           851:                    if (SCpnt->use_sg < max_sg) SCpnt->use_sg++;
        !           852:                }  /* contiguous buffers */
        !           853:            } /* for loop */
        !           854:            
        !           855:            /* This is actually how many we are going to transfer */
        !           856:            this_count = counted; 
        !           857:            
        !           858:            if(count < SCpnt->use_sg || SCpnt->use_sg 
        !           859:               > SCpnt->host->sg_tablesize){
        !           860:                bh = SCpnt->request.bh;
        !           861:                printk("Use sg, count %d %x %d\n", 
        !           862:                       SCpnt->use_sg, count, dma_free_sectors);
        !           863:                printk("maxsg = %x, counted = %d this_count = %d\n", 
        !           864:                       max_sg, counted, this_count);
        !           865:                while(bh){
        !           866:                    printk("[%p %lx] ", bh->b_data, bh->b_size);
        !           867:                    bh = bh->b_reqnext;
        !           868:                }
        !           869:                if(SCpnt->use_sg < 16)
        !           870:                    for(count=0; count<SCpnt->use_sg; count++)
        !           871:                        printk("{%d:%p %p %d}  ", count,
        !           872:                               sgpnt[count].address,
        !           873:                               sgpnt[count].alt_address,
        !           874:                               sgpnt[count].length);
        !           875:                panic("Ooops");
        !           876:            }
        !           877:            
        !           878:            if (SCpnt->request.cmd == WRITE)
        !           879:                for(count=0; count<SCpnt->use_sg; count++)
        !           880:                    if(sgpnt[count].alt_address)
        !           881:                        memcpy(sgpnt[count].address, sgpnt[count].alt_address, 
        !           882:                               sgpnt[count].length);
        !           883:        }  /* Able to malloc sgpnt */
        !           884:     }  /* Host adapter capable of scatter-gather */
        !           885:     
        !           886:     /* Now handle the possibility of DMA to addresses > 16Mb */
        !           887:     
        !           888:     if(SCpnt->use_sg == 0){
        !           889:        if (((long) buff) + (this_count << 9) - 1 > ISA_DMA_THRESHOLD && 
        !           890:            (SCpnt->host->unchecked_isa_dma)) {
        !           891:            if(bounce_buffer)
        !           892:                buff = bounce_buffer;
        !           893:            else
        !           894:                buff = (char *) scsi_malloc(this_count << 9);
        !           895:            if(buff == NULL) {  /* Try backing off a bit if we are low on mem*/
        !           896:                this_count = SCpnt->request.current_nr_sectors;
        !           897:                buff = (char *) scsi_malloc(this_count << 9);
        !           898:                if(!buff) panic("Ran out of DMA buffers.");
        !           899:            }
        !           900:            if (SCpnt->request.cmd == WRITE)
        !           901:                memcpy(buff, (char *)SCpnt->request.buffer, this_count << 9);
        !           902:        }
        !           903:     }
        !           904: #ifdef DEBUG
        !           905:     printk("sd%c : %s %d/%d 512 byte blocks.\n", 
        !           906:           'a' + devm,
        !           907:           (SCpnt->request.cmd == WRITE) ? "writing" : "reading",
        !           908:           this_count, SCpnt->request.nr_sectors);
        !           909: #endif
        !           910:     
        !           911:     cmd[1] = (SCpnt->lun << 5) & 0xe0;
        !           912:     
        !           913:     if (rscsi_disks[dev].sector_size == 1024){
        !           914:        if(block & 1) panic("sd.c:Bad block number requested");
        !           915:        if(this_count & 1) panic("sd.c:Bad block number requested");
        !           916:        block = block >> 1;
        !           917:        this_count = this_count >> 1;
        !           918:     }
        !           919:     
        !           920:     if (rscsi_disks[dev].sector_size == 256){
        !           921:        block = block << 1;
        !           922:        this_count = this_count << 1;
        !           923:     }
        !           924:     
        !           925:     if (((this_count > 0xff) ||  (block > 0x1fffff)) && rscsi_disks[dev].ten)
        !           926:     {
        !           927:        if (this_count > 0xffff)
        !           928:            this_count = 0xffff;
        !           929:        
        !           930:        cmd[0] += READ_10 - READ_6 ;
        !           931:        cmd[2] = (unsigned char) (block >> 24) & 0xff;
        !           932:        cmd[3] = (unsigned char) (block >> 16) & 0xff;
        !           933:        cmd[4] = (unsigned char) (block >> 8) & 0xff;
        !           934:        cmd[5] = (unsigned char) block & 0xff;
        !           935:        cmd[6] = cmd[9] = 0;
        !           936:        cmd[7] = (unsigned char) (this_count >> 8) & 0xff;
        !           937:        cmd[8] = (unsigned char) this_count & 0xff;
        !           938:     }
        !           939:     else
        !           940:     {
        !           941:        if (this_count > 0xff)
        !           942:            this_count = 0xff;
        !           943:        
        !           944:        cmd[1] |= (unsigned char) ((block >> 16) & 0x1f);
        !           945:        cmd[2] = (unsigned char) ((block >> 8) & 0xff);
        !           946:        cmd[3] = (unsigned char) block & 0xff;
        !           947:        cmd[4] = (unsigned char) this_count;
        !           948:        cmd[5] = 0;
        !           949:     }
        !           950:     
        !           951:     /*
        !           952:      * We shouldn't disconnect in the middle of a sector, so with a dumb 
        !           953:      * host adapter, it's safe to assume that we can at least transfer 
        !           954:      * this many bytes between each connect / disconnect.  
        !           955:      */
        !           956:     
        !           957:     SCpnt->transfersize = rscsi_disks[dev].sector_size;
        !           958:     SCpnt->underflow = this_count << 9; 
        !           959:     scsi_do_cmd (SCpnt, (void *) cmd, buff, 
        !           960:                 this_count * rscsi_disks[dev].sector_size,
        !           961:                 rw_intr, 
        !           962:                 (SCpnt->device->type == TYPE_DISK ? 
        !           963:                  SD_TIMEOUT : SD_MOD_TIMEOUT),
        !           964:                 MAX_RETRIES);
        !           965: }
        !           966: 
        !           967: static int check_scsidisk_media_change(kdev_t full_dev){
        !           968:     int retval;
        !           969:     int target;
        !           970:     struct inode inode;
        !           971:     int flag = 0;
        !           972:     
        !           973:     target =  DEVICE_NR(full_dev);
        !           974:     
        !           975:     if (target >= sd_template.dev_max ||
        !           976:        !rscsi_disks[target].device) {
        !           977:        printk("SCSI disk request error: invalid device.\n");
        !           978:        return 0;
        !           979:     }
        !           980:     
        !           981:     if(!rscsi_disks[target].device->removable) return 0;
        !           982:     
        !           983:     inode.i_rdev = full_dev;  /* This is all we really need here */
        !           984: 
        !           985:     /* Using Start/Stop enables differentiation between drive with
        !           986:      * no cartridge loaded - NOT READY, drive with changed cartridge -
        !           987:      * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
        !           988:      * This also handles drives that auto spin down. eg iomega jaz 1GB
        !           989:      * as this will spin up the drive.
        !           990:      */
        !           991:     retval = sd_ioctl(&inode, NULL, SCSI_IOCTL_START_UNIT, 0);
        !           992:     
        !           993:     if(retval){ /* Unable to test, unit probably not ready.  This usually
        !           994:                 * means there is no disc in the drive.  Mark as changed,
        !           995:                 * and we will figure it out later once the drive is
        !           996:                 * available again.  */
        !           997:        
        !           998:        rscsi_disks[target].ready = 0;
        !           999:        rscsi_disks[target].device->changed = 1;
        !          1000:        return 1; /* This will force a flush, if called from
        !          1001:                   * check_disk_change */
        !          1002:     }
        !          1003:     
        !          1004:     /* 
        !          1005:      * for removable scsi disk ( FLOPTICAL ) we have to recognise the
        !          1006:      * presence of disk in the drive. This is kept in the Scsi_Disk
        !          1007:      * struct and tested at open !  Daniel Roche ( [email protected] ) 
        !          1008:      */
        !          1009:     
        !          1010:     rscsi_disks[target].ready = 1;     /* FLOPTICAL */
        !          1011: 
        !          1012:     retval = rscsi_disks[target].device->changed;
        !          1013:     if(!flag) rscsi_disks[target].device->changed = 0;
        !          1014:     return retval;
        !          1015: }
        !          1016: 
        !          1017: static void sd_init_done (Scsi_Cmnd * SCpnt)
        !          1018: {
        !          1019:     struct request * req;
        !          1020:     
        !          1021:     req = &SCpnt->request;
        !          1022:     req->rq_status = RQ_SCSI_DONE; /* Busy, but indicate request done */
        !          1023:     
        !          1024:     if (req->sem != NULL) {
        !          1025:        up(req->sem);
        !          1026:     }
        !          1027: }
        !          1028: 
        !          1029: static int sd_init_onedisk(int i)
        !          1030: {
        !          1031:     unsigned char cmd[10];
        !          1032:     unsigned char *buffer;
        !          1033:     unsigned long spintime;
        !          1034:     int the_result, retries;
        !          1035:     Scsi_Cmnd * SCpnt;
        !          1036:     
        !          1037:     /* We need to retry the READ_CAPACITY because a UNIT_ATTENTION is 
        !          1038:      * considered a fatal error, and many devices report such an error 
        !          1039:      * just after a scsi bus reset. 
        !          1040:      */
        !          1041:     
        !          1042:     SCpnt = allocate_device(NULL, rscsi_disks[i].device, 1);
        !          1043:     buffer = (unsigned char *) scsi_malloc(512);
        !          1044:     
        !          1045:     spintime = 0;
        !          1046:     
        !          1047:     /* Spin up drives, as required.  Only do this at boot time */
        !          1048:     /* Spinup needs to be done for module loads too. */
        !          1049:        do{
        !          1050:            retries = 0;
        !          1051:            while(retries < 3)
        !          1052:            {
        !          1053:                cmd[0] = TEST_UNIT_READY;
        !          1054:                cmd[1] = (rscsi_disks[i].device->lun << 5) & 0xe0;
        !          1055:                memset ((void *) &cmd[2], 0, 8);
        !          1056:                SCpnt->cmd_len = 0;
        !          1057:                SCpnt->sense_buffer[0] = 0;
        !          1058:                SCpnt->sense_buffer[2] = 0;
        !          1059: 
        !          1060:                {
        !          1061:                    struct semaphore sem = MUTEX_LOCKED;
        !          1062:                    /* Mark as really busy again */
        !          1063:                    SCpnt->request.rq_status = RQ_SCSI_BUSY;
        !          1064:                    SCpnt->request.sem = &sem;
        !          1065:                    scsi_do_cmd (SCpnt,
        !          1066:                                 (void *) cmd, (void *) buffer,
        !          1067:                                 512, sd_init_done,  SD_TIMEOUT,
        !          1068:                                 MAX_RETRIES);
        !          1069:                    down(&sem);
        !          1070:                }
        !          1071: 
        !          1072:                the_result = SCpnt->result;
        !          1073:                retries++;
        !          1074:                if(   the_result == 0
        !          1075:                   || SCpnt->sense_buffer[2] != UNIT_ATTENTION)
        !          1076:                    break;
        !          1077:            }
        !          1078:            
        !          1079:            /* Look for non-removable devices that return NOT_READY.  
        !          1080:             * Issue command to spin up drive for these cases. */
        !          1081:            if(the_result && !rscsi_disks[i].device->removable && 
        !          1082:               SCpnt->sense_buffer[2] == NOT_READY) {
        !          1083:                unsigned long time1;
        !          1084:                if(!spintime){
        !          1085: #ifdef MACH
        !          1086:                     printk( "sd%d: Spinning up disk...", i);
        !          1087: #else
        !          1088:                    printk( "sd%c: Spinning up disk...", 'a' + i );
        !          1089: #endif
        !          1090:                    cmd[0] = START_STOP;
        !          1091:                    cmd[1] = (rscsi_disks[i].device->lun << 5) & 0xe0;
        !          1092:                    cmd[1] |= 1;  /* Return immediately */
        !          1093:                    memset ((void *) &cmd[2], 0, 8);
        !          1094:                    cmd[4] = 1; /* Start spin cycle */
        !          1095:                    SCpnt->cmd_len = 0;
        !          1096:                    SCpnt->sense_buffer[0] = 0;
        !          1097:                    SCpnt->sense_buffer[2] = 0;
        !          1098:                    
        !          1099:                    {
        !          1100:                        struct semaphore sem = MUTEX_LOCKED;
        !          1101:                        /* Mark as really busy again */
        !          1102:                        SCpnt->request.rq_status = RQ_SCSI_BUSY; 
        !          1103:                        SCpnt->request.sem = &sem;
        !          1104:                        scsi_do_cmd (SCpnt,
        !          1105:                                     (void *) cmd, (void *) buffer,
        !          1106:                                     512, sd_init_done,  SD_TIMEOUT,
        !          1107:                                     MAX_RETRIES);
        !          1108:                        down(&sem);
        !          1109:                    }
        !          1110:                    
        !          1111:                    spintime = jiffies;
        !          1112:                }
        !          1113:                
        !          1114:                time1 = jiffies + HZ;
        !          1115:                while(jiffies < time1); /* Wait 1 second for next try */
        !          1116:                printk( "." );
        !          1117:            }
        !          1118:        } while(the_result && spintime && spintime+100*HZ > jiffies);
        !          1119:        if (spintime) {
        !          1120:            if (the_result)
        !          1121:                printk( "not responding...\n" );
        !          1122:            else
        !          1123:                printk( "ready\n" );
        !          1124:        }
        !          1125:     
        !          1126:     retries = 3;
        !          1127:     do {
        !          1128:        cmd[0] = READ_CAPACITY;
        !          1129:        cmd[1] = (rscsi_disks[i].device->lun << 5) & 0xe0;
        !          1130:        memset ((void *) &cmd[2], 0, 8);
        !          1131:        memset ((void *) buffer, 0, 8);
        !          1132:        SCpnt->cmd_len = 0;
        !          1133:        SCpnt->sense_buffer[0] = 0;
        !          1134:        SCpnt->sense_buffer[2] = 0;
        !          1135: 
        !          1136:        {
        !          1137:            struct semaphore sem = MUTEX_LOCKED;
        !          1138:            /* Mark as really busy again */
        !          1139:            SCpnt->request.rq_status = RQ_SCSI_BUSY;
        !          1140:            SCpnt->request.sem = &sem;
        !          1141:            scsi_do_cmd (SCpnt,
        !          1142:                         (void *) cmd, (void *) buffer,
        !          1143:                         8, sd_init_done,  SD_TIMEOUT,
        !          1144:                         MAX_RETRIES);
        !          1145:            down(&sem); /* sleep until it is ready */
        !          1146:        }
        !          1147:        
        !          1148:        the_result = SCpnt->result;
        !          1149:        retries--;
        !          1150:        
        !          1151:     } while(the_result && retries);
        !          1152:     
        !          1153:     SCpnt->request.rq_status = RQ_INACTIVE;  /* Mark as not busy */
        !          1154:     
        !          1155:     wake_up(&SCpnt->device->device_wait); 
        !          1156:     
        !          1157:     /* Wake up a process waiting for device */
        !          1158:     
        !          1159:     /*
        !          1160:      * The SCSI standard says: 
        !          1161:      * "READ CAPACITY is necessary for self configuring software"
        !          1162:      *  While not mandatory, support of READ CAPACITY is strongly encouraged.
        !          1163:      *  We used to die if we couldn't successfully do a READ CAPACITY.
        !          1164:      *  But, now we go on about our way.  The side effects of this are
        !          1165:      *
        !          1166:      *  1. We can't know block size with certainty. I have said "512 bytes 
        !          1167:      *     is it" as this is most common.
        !          1168:      *
        !          1169:      *  2. Recovery from when some one attempts to read past the end of the 
        !          1170:      *     raw device will be slower.
        !          1171:      */
        !          1172:     
        !          1173:     if (the_result)
        !          1174:     {
        !          1175: #ifdef MACH
        !          1176:        printk ("sd%d : READ CAPACITY failed.\n"
        !          1177:                "sd%d : status = %x, message = %02x, host = %d, driver = %02x \n",
        !          1178:                 i, i,
        !          1179: #else
        !          1180:        printk ("sd%c : READ CAPACITY failed.\n"
        !          1181:                "sd%c : status = %x, message = %02x, host = %d, driver = %02x \n",
        !          1182:                'a' + i, 'a' + i,
        !          1183: #endif
        !          1184:                status_byte(the_result),
        !          1185:                msg_byte(the_result),
        !          1186:                host_byte(the_result),
        !          1187:                driver_byte(the_result)
        !          1188:                );
        !          1189:        if (driver_byte(the_result)  & DRIVER_SENSE)
        !          1190: #ifdef MACH
        !          1191:            printk("sd%d : extended sense code = %1x \n", 
        !          1192:                   i, SCpnt->sense_buffer[2] & 0xf);
        !          1193: #else
        !          1194:            printk("sd%c : extended sense code = %1x \n", 
        !          1195:                   'a' + i, SCpnt->sense_buffer[2] & 0xf);
        !          1196: #endif
        !          1197:        else
        !          1198: #ifdef MACH
        !          1199:            printk("sd%d : sense not available. \n", i);
        !          1200: #else
        !          1201:            printk("sd%c : sense not available. \n", 'a' + i);
        !          1202: #endif
        !          1203: 
        !          1204: #ifdef MACH
        !          1205:        printk("sd%d : block size assumed to be 512 bytes, disk size 1GB.  \n",
        !          1206:               i);
        !          1207: #else
        !          1208:        printk("sd%c : block size assumed to be 512 bytes, disk size 1GB.  \n",
        !          1209:               'a' + i);
        !          1210: #endif
        !          1211:        rscsi_disks[i].capacity = 0x1fffff;
        !          1212:        rscsi_disks[i].sector_size = 512;
        !          1213:        
        !          1214:        /* Set dirty bit for removable devices if not ready - sometimes drives
        !          1215:         * will not report this properly. */
        !          1216:        if(rscsi_disks[i].device->removable && 
        !          1217:           SCpnt->sense_buffer[2] == NOT_READY)
        !          1218:            rscsi_disks[i].device->changed = 1;
        !          1219:        
        !          1220:     }
        !          1221:     else
        !          1222:     {
        !          1223:        /*
        !          1224:         * FLOPTICAL , if read_capa is ok , drive is assumed to be ready 
        !          1225:         */
        !          1226:        rscsi_disks[i].ready = 1;
        !          1227: 
        !          1228:        rscsi_disks[i].capacity = 1 + ((buffer[0] << 24) |
        !          1229:                                       (buffer[1] << 16) |
        !          1230:                                       (buffer[2] << 8) |
        !          1231:                                       buffer[3]);
        !          1232:        
        !          1233:        rscsi_disks[i].sector_size = (buffer[4] << 24) |
        !          1234:            (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
        !          1235: 
        !          1236:        if (rscsi_disks[i].sector_size == 0) {
        !          1237:          rscsi_disks[i].sector_size = 512;
        !          1238: #ifdef MACH
        !          1239:          printk("sd%d : sector size 0 reported, assuming 512.\n", i);
        !          1240: #else
        !          1241:          printk("sd%c : sector size 0 reported, assuming 512.\n", 'a' + i);
        !          1242: #endif
        !          1243:        }
        !          1244:  
        !          1245:        
        !          1246:        if (rscsi_disks[i].sector_size != 512 &&
        !          1247:            rscsi_disks[i].sector_size != 1024 &&
        !          1248:            rscsi_disks[i].sector_size != 256)
        !          1249:        {
        !          1250: #ifdef MACH
        !          1251:            printk ("sd%d : unsupported sector size %d.\n",
        !          1252:                    i, rscsi_disks[i].sector_size);
        !          1253: #else
        !          1254:            printk ("sd%c : unsupported sector size %d.\n",
        !          1255:                    'a' + i, rscsi_disks[i].sector_size);
        !          1256: #endif
        !          1257:            if(rscsi_disks[i].device->removable){
        !          1258:                rscsi_disks[i].capacity = 0;
        !          1259:            } else {
        !          1260:                printk ("scsi : deleting disk entry.\n");
        !          1261:                rscsi_disks[i].device = NULL;
        !          1262:                sd_template.nr_dev--;
        !          1263:                sd_gendisk.nr_real--;
        !          1264:                return i;
        !          1265:            }
        !          1266:        }
        !          1267:     {
        !          1268:        /*
        !          1269:         * The msdos fs needs to know the hardware sector size
        !          1270:         * So I have created this table. See ll_rw_blk.c
        !          1271:         * Jacques Gelinas ([email protected])
        !          1272:         */
        !          1273:        int m, mb;
        !          1274:         int sz_quot, sz_rem;
        !          1275:        int hard_sector = rscsi_disks[i].sector_size;
        !          1276:        /* There are 16 minors allocated for each major device */
        !          1277:        for (m=i<<4; m<((i+1)<<4); m++){
        !          1278:            sd_hardsizes[m] = hard_sector;
        !          1279:        }
        !          1280:         mb = rscsi_disks[i].capacity / 1024 * hard_sector / 1024;
        !          1281:         /* sz = div(m/100, 10);  this seems to not be in the libr */
        !          1282:         m = (mb + 50) / 100;
        !          1283:         sz_quot = m / 10;
        !          1284:         sz_rem = m - (10 * sz_quot);
        !          1285: #ifdef MACH
        !          1286:        printk ("SCSI device sd%d: hdwr sector= %d bytes."
        !          1287:                " Sectors= %d [%d MB] [%d.%1d GB]\n",
        !          1288:                i, hard_sector, rscsi_disks[i].capacity, 
        !          1289:                 mb, sz_quot, sz_rem);
        !          1290: #else
        !          1291:        printk ("SCSI device sd%c: hdwr sector= %d bytes."
        !          1292:                " Sectors= %d [%d MB] [%d.%1d GB]\n",
        !          1293:                i+'a', hard_sector, rscsi_disks[i].capacity, 
        !          1294:                 mb, sz_quot, sz_rem);
        !          1295: #endif
        !          1296:     }
        !          1297:        if(rscsi_disks[i].sector_size == 1024)
        !          1298:            rscsi_disks[i].capacity <<= 1;  /* Change into 512 byte sectors */
        !          1299:        if(rscsi_disks[i].sector_size == 256)
        !          1300:            rscsi_disks[i].capacity >>= 1;  /* Change into 512 byte sectors */
        !          1301:     }
        !          1302:     
        !          1303: 
        !          1304:     /*
        !          1305:      * Unless otherwise specified, this is not write protected.
        !          1306:      */
        !          1307:     rscsi_disks[i].write_prot = 0;
        !          1308:     if ( rscsi_disks[i].device->removable && rscsi_disks[i].ready ) {
        !          1309:        /* FLOPTICAL */
        !          1310: 
        !          1311:        /* 
        !          1312:         *      for removable scsi disk ( FLOPTICAL ) we have to recognise  
        !          1313:         * the Write Protect Flag. This flag is kept in the Scsi_Disk struct
        !          1314:         * and tested at open !
        !          1315:         * Daniel Roche ( [email protected] )
        !          1316:         */
        !          1317:        
        !          1318:        memset ((void *) &cmd[0], 0, 8);
        !          1319:        cmd[0] = MODE_SENSE;
        !          1320:        cmd[1] = (rscsi_disks[i].device->lun << 5) & 0xe0;
        !          1321:        cmd[2] = 1;      /* page code 1 ?? */
        !          1322:        cmd[4] = 12;
        !          1323:        SCpnt->cmd_len = 0;
        !          1324:        SCpnt->sense_buffer[0] = 0;
        !          1325:        SCpnt->sense_buffer[2] = 0;
        !          1326: 
        !          1327:        /* same code as READCAPA !! */
        !          1328:        {
        !          1329:            struct semaphore sem = MUTEX_LOCKED;
        !          1330:            SCpnt->request.rq_status = RQ_SCSI_BUSY;  /* Mark as really busy again */
        !          1331:            SCpnt->request.sem = &sem;
        !          1332:            scsi_do_cmd (SCpnt,
        !          1333:                         (void *) cmd, (void *) buffer,
        !          1334:                         512, sd_init_done,  SD_TIMEOUT,
        !          1335:                         MAX_RETRIES);
        !          1336:            down(&sem);
        !          1337:        }
        !          1338:        
        !          1339:        the_result = SCpnt->result;
        !          1340:        SCpnt->request.rq_status = RQ_INACTIVE;  /* Mark as not busy */
        !          1341:        wake_up(&SCpnt->device->device_wait); 
        !          1342:        
        !          1343:        if ( the_result ) {
        !          1344: #ifdef MACH
        !          1345:            printk ("sd%d: test WP failed, assume Write Protected\n",i);
        !          1346: #else
        !          1347:            printk ("sd%c: test WP failed, assume Write Protected\n",i+'a');
        !          1348: #endif
        !          1349:            rscsi_disks[i].write_prot = 1;
        !          1350:        } else {
        !          1351:            rscsi_disks[i].write_prot = ((buffer[2] & 0x80) != 0);
        !          1352: #ifdef MACH
        !          1353:            printk ("sd%d: Write Protect is %s\n",i,
        !          1354:                    rscsi_disks[i].write_prot ? "on" : "off");
        !          1355: #else
        !          1356:            printk ("sd%c: Write Protect is %s\n",i+'a',
        !          1357:                    rscsi_disks[i].write_prot ? "on" : "off");
        !          1358: #endif
        !          1359:        }
        !          1360:        
        !          1361:     }  /* check for write protect */
        !          1362:  
        !          1363:     rscsi_disks[i].ten = 1;
        !          1364:     rscsi_disks[i].remap = 1;
        !          1365:     scsi_free(buffer, 512);
        !          1366:     return i;
        !          1367: }
        !          1368: 
        !          1369: /*
        !          1370:  * The sd_init() function looks at all SCSI drives present, determines
        !          1371:  * their size, and reads partition table entries for them.
        !          1372:  */
        !          1373: 
        !          1374: static int sd_registered = 0;
        !          1375: 
        !          1376: static int sd_init()
        !          1377: {
        !          1378:     int i;
        !          1379:     
        !          1380:     if (sd_template.dev_noticed == 0) return 0;
        !          1381:     
        !          1382:     if(!sd_registered) {
        !          1383:          if (register_blkdev(MAJOR_NR,"sd",&sd_fops)) {
        !          1384:              printk("Unable to get major %d for SCSI disk\n",MAJOR_NR);
        !          1385:              return 1;
        !          1386:          }
        !          1387:          sd_registered++;
        !          1388:       }
        !          1389:     
        !          1390:     /* We do not support attaching loadable devices yet. */
        !          1391:     if(rscsi_disks) return 0;
        !          1392:     
        !          1393:     sd_template.dev_max = sd_template.dev_noticed + SD_EXTRA_DEVS;
        !          1394:     
        !          1395:     rscsi_disks = (Scsi_Disk *) 
        !          1396:        scsi_init_malloc(sd_template.dev_max * sizeof(Scsi_Disk), GFP_ATOMIC);
        !          1397:     memset(rscsi_disks, 0, sd_template.dev_max * sizeof(Scsi_Disk));
        !          1398:     
        !          1399:     sd_sizes = (int *) scsi_init_malloc((sd_template.dev_max << 4) * 
        !          1400:                                        sizeof(int), GFP_ATOMIC);
        !          1401:     memset(sd_sizes, 0, (sd_template.dev_max << 4) * sizeof(int));
        !          1402:     
        !          1403:     sd_blocksizes = (int *) scsi_init_malloc((sd_template.dev_max << 4) * 
        !          1404:                                             sizeof(int), GFP_ATOMIC);
        !          1405:     
        !          1406:     sd_hardsizes = (int *) scsi_init_malloc((sd_template.dev_max << 4) * 
        !          1407:                                            sizeof(int), GFP_ATOMIC);
        !          1408:     
        !          1409:     for(i=0;i<(sd_template.dev_max << 4);i++){
        !          1410:        sd_blocksizes[i] = 1024;
        !          1411:        sd_hardsizes[i] = 512;
        !          1412:     }
        !          1413:     blksize_size[MAJOR_NR] = sd_blocksizes;
        !          1414:     hardsect_size[MAJOR_NR] = sd_hardsizes;
        !          1415:     sd = (struct hd_struct *) scsi_init_malloc((sd_template.dev_max << 4) *
        !          1416:                                               sizeof(struct hd_struct),
        !          1417:                                               GFP_ATOMIC);
        !          1418:     
        !          1419:     
        !          1420:     sd_gendisk.max_nr = sd_template.dev_max;
        !          1421:     sd_gendisk.part = sd;
        !          1422:     sd_gendisk.sizes = sd_sizes;
        !          1423:     sd_gendisk.real_devices = (void *) rscsi_disks;
        !          1424:     return 0;
        !          1425: }
        !          1426: 
        !          1427: static void sd_finish(void)
        !          1428: {
        !          1429:     struct gendisk *gendisk;
        !          1430:     int i;
        !          1431: 
        !          1432:     blk_dev[MAJOR_NR].request_fn = DEVICE_REQUEST;
        !          1433:     
        !          1434:     for (gendisk = gendisk_head; gendisk != NULL; gendisk = gendisk->next)
        !          1435:       if (gendisk == &sd_gendisk)
        !          1436:        break;
        !          1437:     if (gendisk == NULL)
        !          1438:       {
        !          1439:        sd_gendisk.next = gendisk_head;
        !          1440:        gendisk_head = &sd_gendisk;
        !          1441:       }
        !          1442:     
        !          1443:     for (i = 0; i < sd_template.dev_max; ++i)
        !          1444:        if (!rscsi_disks[i].capacity && 
        !          1445:            rscsi_disks[i].device)
        !          1446:        {
        !          1447:            if (MODULE_FLAG
        !          1448:                && !rscsi_disks[i].has_part_table) {
        !          1449:                sd_sizes[i << 4] = rscsi_disks[i].capacity;
        !          1450:                /* revalidate does sd_init_onedisk via MAYBE_REINIT*/
        !          1451:                revalidate_scsidisk(MKDEV(MAJOR_NR, i << 4), 0);
        !          1452:            }
        !          1453:            else
        !          1454:                i=sd_init_onedisk(i);
        !          1455:            rscsi_disks[i].has_part_table = 1;
        !          1456:        }
        !          1457:     
        !          1458:     /* If our host adapter is capable of scatter-gather, then we increase
        !          1459:      * the read-ahead to 16 blocks (32 sectors).  If not, we use
        !          1460:      * a two block (4 sector) read ahead. 
        !          1461:      */
        !          1462:     if(rscsi_disks[0].device && rscsi_disks[0].device->host->sg_tablesize)
        !          1463:        read_ahead[MAJOR_NR] = 120;  /* 120 sector read-ahead */
        !          1464:     else
        !          1465:        read_ahead[MAJOR_NR] = 4;  /* 4 sector read-ahead */
        !          1466: 
        !          1467:     return;
        !          1468: }
        !          1469: 
        !          1470: static int sd_detect(Scsi_Device * SDp){
        !          1471:     if(SDp->type != TYPE_DISK && SDp->type != TYPE_MOD) return 0;
        !          1472: 
        !          1473: #ifdef MACH
        !          1474:     printk("Detected scsi %sdisk sd%d at scsi%d, channel %d, id %d, lun %d\n", 
        !          1475:            SDp->removable ? "removable " : "",
        !          1476:           sd_template.dev_noticed++,
        !          1477:           SDp->host->host_no, SDp->channel, SDp->id, SDp->lun);
        !          1478: #else
        !          1479:     printk("Detected scsi %sdisk sd%c at scsi%d, channel %d, id %d, lun %d\n", 
        !          1480:            SDp->removable ? "removable " : "",
        !          1481:           'a'+ (sd_template.dev_noticed++),
        !          1482:           SDp->host->host_no, SDp->channel, SDp->id, SDp->lun);
        !          1483: #endif
        !          1484:     
        !          1485:     return 1;
        !          1486: }
        !          1487: 
        !          1488: static int sd_attach(Scsi_Device * SDp){
        !          1489:     Scsi_Disk * dpnt;
        !          1490:     int i;
        !          1491:     
        !          1492:     if(SDp->type != TYPE_DISK && SDp->type != TYPE_MOD) return 0;
        !          1493:     
        !          1494:     if(sd_template.nr_dev >= sd_template.dev_max) {
        !          1495:        SDp->attached--;
        !          1496:        return 1;
        !          1497:     }
        !          1498:     
        !          1499:     for(dpnt = rscsi_disks, i=0; i<sd_template.dev_max; i++, dpnt++) 
        !          1500:        if(!dpnt->device) break;
        !          1501:     
        !          1502:     if(i >= sd_template.dev_max) panic ("scsi_devices corrupt (sd)");
        !          1503:     
        !          1504:     SDp->scsi_request_fn = do_sd_request;
        !          1505:     rscsi_disks[i].device = SDp;
        !          1506:     rscsi_disks[i].has_part_table = 0;
        !          1507:     sd_template.nr_dev++;
        !          1508:     sd_gendisk.nr_real++;
        !          1509:     return 0;
        !          1510: }
        !          1511: 
        !          1512: #define DEVICE_BUSY rscsi_disks[target].device->busy
        !          1513: #define USAGE rscsi_disks[target].device->access_count
        !          1514: #define CAPACITY rscsi_disks[target].capacity
        !          1515: #define MAYBE_REINIT  sd_init_onedisk(target)
        !          1516: #define GENDISK_STRUCT sd_gendisk
        !          1517: 
        !          1518: /* This routine is called to flush all partitions and partition tables
        !          1519:  * for a changed scsi disk, and then re-read the new partition table.
        !          1520:  * If we are revalidating a disk because of a media change, then we
        !          1521:  * enter with usage == 0.  If we are using an ioctl, we automatically have
        !          1522:  * usage == 1 (we need an open channel to use an ioctl :-), so this
        !          1523:  * is our limit.
        !          1524:  */
        !          1525: int revalidate_scsidisk(kdev_t dev, int maxusage){
        !          1526:     int target;
        !          1527:     struct gendisk * gdev;
        !          1528:     unsigned long flags;
        !          1529:     int max_p;
        !          1530:     int start;
        !          1531:     int i;
        !          1532:     
        !          1533:     target =  DEVICE_NR(dev);
        !          1534:     gdev = &GENDISK_STRUCT;
        !          1535:     
        !          1536:     save_flags(flags);
        !          1537:     cli();
        !          1538:     if (DEVICE_BUSY || USAGE > maxusage) {
        !          1539:        restore_flags(flags);
        !          1540:        printk("Device busy for revalidation (usage=%d)\n", USAGE);
        !          1541:        return -EBUSY;
        !          1542:     }
        !          1543:     DEVICE_BUSY = 1;
        !          1544:     restore_flags(flags);
        !          1545:     
        !          1546:     max_p = gdev->max_p;
        !          1547:     start = target << gdev->minor_shift;
        !          1548:     
        !          1549:     for (i=max_p - 1; i >=0 ; i--) {
        !          1550:        int minor = start+i;
        !          1551:        kdev_t devi = MKDEV(MAJOR_NR, minor);
        !          1552:        sync_dev(devi);
        !          1553:        invalidate_inodes(devi);
        !          1554:        invalidate_buffers(devi);
        !          1555:        gdev->part[minor].start_sect = 0;
        !          1556:        gdev->part[minor].nr_sects = 0;
        !          1557:         /*
        !          1558:          * Reset the blocksize for everything so that we can read
        !          1559:          * the partition table.
        !          1560:          */
        !          1561:         blksize_size[MAJOR_NR][minor] = 1024;
        !          1562:     }
        !          1563:     
        !          1564: #ifdef MAYBE_REINIT
        !          1565:     MAYBE_REINIT;
        !          1566: #endif
        !          1567:     
        !          1568:     gdev->part[start].nr_sects = CAPACITY;
        !          1569:     resetup_one_dev(gdev, target);
        !          1570:     
        !          1571:     DEVICE_BUSY = 0;
        !          1572:     return 0;
        !          1573: }
        !          1574: 
        !          1575: static int fop_revalidate_scsidisk(kdev_t dev){
        !          1576:     return revalidate_scsidisk(dev, 0);
        !          1577: }
        !          1578: 
        !          1579: 
        !          1580: static void sd_detach(Scsi_Device * SDp)
        !          1581: {
        !          1582:     Scsi_Disk * dpnt;
        !          1583:     int i;
        !          1584:     int max_p;
        !          1585:     int start;
        !          1586:     
        !          1587:     for(dpnt = rscsi_disks, i=0; i<sd_template.dev_max; i++, dpnt++) 
        !          1588:        if(dpnt->device == SDp) {
        !          1589:            
        !          1590:            /* If we are disconnecting a disk driver, sync and invalidate 
        !          1591:             * everything */
        !          1592:            max_p = sd_gendisk.max_p;
        !          1593:            start = i << sd_gendisk.minor_shift;
        !          1594:            
        !          1595:            for (i=max_p - 1; i >=0 ; i--) {
        !          1596:                int minor = start+i;
        !          1597:                kdev_t devi = MKDEV(MAJOR_NR, minor);
        !          1598:                sync_dev(devi);
        !          1599:                invalidate_inodes(devi);
        !          1600:                invalidate_buffers(devi);
        !          1601:                sd_gendisk.part[minor].start_sect = 0;
        !          1602:                sd_gendisk.part[minor].nr_sects = 0;
        !          1603:                sd_sizes[minor] = 0;
        !          1604:            }
        !          1605:            
        !          1606:            dpnt->has_part_table = 0;
        !          1607:            dpnt->device = NULL;
        !          1608:            dpnt->capacity = 0;
        !          1609:            SDp->attached--;
        !          1610:            sd_template.dev_noticed--;
        !          1611:            sd_template.nr_dev--;
        !          1612:            sd_gendisk.nr_real--;
        !          1613:            return;
        !          1614:        }
        !          1615:     return;
        !          1616: }
        !          1617: 
        !          1618: #ifdef MODULE
        !          1619: 
        !          1620: int init_module(void) {
        !          1621:     sd_template.usage_count = &mod_use_count_;
        !          1622:     return scsi_register_module(MODULE_SCSI_DEV, &sd_template);
        !          1623: }
        !          1624: 
        !          1625: void cleanup_module( void) 
        !          1626: {
        !          1627:     struct gendisk * prev_sdgd;
        !          1628:     struct gendisk * sdgd;
        !          1629:     
        !          1630:     scsi_unregister_module(MODULE_SCSI_DEV, &sd_template);
        !          1631:     unregister_blkdev(SCSI_DISK_MAJOR, "sd");
        !          1632:     sd_registered--;
        !          1633:     if( rscsi_disks != NULL )
        !          1634:     {
        !          1635:        scsi_init_free((char *) rscsi_disks,
        !          1636:                       (sd_template.dev_noticed + SD_EXTRA_DEVS) 
        !          1637:                       * sizeof(Scsi_Disk));
        !          1638:        
        !          1639:        scsi_init_free((char *) sd_sizes, sd_template.dev_max * sizeof(int));
        !          1640:        scsi_init_free((char *) sd_blocksizes, sd_template.dev_max * sizeof(int));
        !          1641:        scsi_init_free((char *) sd_hardsizes, sd_template.dev_max * sizeof(int));
        !          1642:        scsi_init_free((char *) sd, 
        !          1643:                       (sd_template.dev_max << 4) * sizeof(struct hd_struct));
        !          1644:        /*
        !          1645:         * Now remove sd_gendisk from the linked list
        !          1646:         */
        !          1647:        sdgd = gendisk_head;
        !          1648:        prev_sdgd = NULL;
        !          1649:        while(sdgd != &sd_gendisk)
        !          1650:        {
        !          1651:            prev_sdgd = sdgd;
        !          1652:            sdgd = sdgd->next;
        !          1653:        }
        !          1654:        
        !          1655:        if(sdgd != &sd_gendisk)
        !          1656:            printk("sd_gendisk not in disk chain.\n");
        !          1657:        else {
        !          1658:            if(prev_sdgd != NULL)
        !          1659:                prev_sdgd->next = sdgd->next;
        !          1660:            else
        !          1661:                gendisk_head = sdgd->next;
        !          1662:        }
        !          1663:     }
        !          1664:     
        !          1665:     blksize_size[MAJOR_NR] = NULL;
        !          1666:     blk_dev[MAJOR_NR].request_fn = NULL;
        !          1667:     blk_size[MAJOR_NR] = NULL;  
        !          1668:     hardsect_size[MAJOR_NR] = NULL;
        !          1669:     read_ahead[MAJOR_NR] = 0;
        !          1670:     sd_template.dev_max = 0;
        !          1671: }
        !          1672: #endif /* MODULE */
        !          1673: 
        !          1674: /*
        !          1675:  * Overrides for Emacs so that we almost follow Linus's tabbing style.
        !          1676:  * Emacs will notice this stuff at the end of the file and automatically
        !          1677:  * adjust the settings for this buffer only.  This must remain at the end
        !          1678:  * of the file.
        !          1679:  * ---------------------------------------------------------------------------
        !          1680:  * Local variables:
        !          1681:  * c-indent-level: 4
        !          1682:  * c-brace-imaginary-offset: 0
        !          1683:  * c-brace-offset: -4
        !          1684:  * c-argdecl-indent: 4
        !          1685:  * c-label-offset: -4
        !          1686:  * c-continued-statement-offset: 4
        !          1687:  * c-continued-brace-offset: 0
        !          1688:  * indent-tabs-mode: nil
        !          1689:  * tab-width: 8
        !          1690:  * End:
        !          1691:  */

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