/**
* sd_init_command - build a scsi (read or write) command from
* information in the request structure.
* @SCpnt: pointer to mid-level's per scsi command structure that
* contains request and into which the scsi command is written
*
* Returns 1 if successful and 0 if error (or cannot be done now).
**/
static int sd_init_command(struct scsi_cmnd * SCpnt)
{
unsigned int this_count, timeout;
struct gendisk *disk;
sector_t block;
struct scsi_device *sdp = SCpnt->device;
timeout = sdp->timeout;
/*
* these are already setup, just copy cdb basically
*/
if (SCpnt->request->flags & REQ_BLOCK_PC) {
struct request *rq = SCpnt->request;
if (sizeof(rq->cmd) > sizeof(SCpnt->cmnd))
return 0;
memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd));
if (rq_data_dir(rq) == WRITE)
SCpnt->sc_data_direction = DMA_TO_DEVICE;
else if (rq->data_len)
SCpnt->sc_data_direction = DMA_FROM_DEVICE;
else
SCpnt->sc_data_direction = DMA_NONE;
this_count = rq->data_len;
if (rq->timeout)
timeout = rq->timeout;
SCpnt->transfersize = rq->data_len;
goto queue;
}
/*
* we only do REQ_CMD and REQ_BLOCK_PC
*/
if (!(SCpnt->request->flags & REQ_CMD))
return 0;
disk = SCpnt->request->rq_disk;
block = SCpnt->request->sector;
this_count = SCpnt->request_bufflen >> 9;
SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, "
"count=%d\n", disk->disk_name, (unsigned long long)block, this_count));
if (!sdp || !scsi_device_online(sdp) ||
block + SCpnt->request->nr_sectors > get_capacity(disk)) {
SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
SCpnt->request->nr_sectors));
SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
return 0;
}
if (sdp->changed) {
/*
* quietly refuse to do anything to a changed disc until
* the changed bit has been reset
*/
/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
return 0;
}
SCSI_LOG_HLQUEUE(2, printk("%s : block=%llu\n",
disk->disk_name, (unsigned long long)block));
/*
* If we have a 1K hardware sectorsize, prevent access to single
* 512 byte sectors. In theory we could handle this - in fact
* the scsi cdrom driver must be able to handle this because
* we typically use 1K blocksizes, and cdroms typically have
* 2K hardware sectorsizes. Of course, things are simpler
* with the cdrom, since it is read-only. For performance
* reasons, the filesystems should be able to handle this
* and not force the scsi disk driver to use bounce buffers
* for this.
*/
if (sdp->sector_size == 1024) {
if ((block & 1) || (SCpnt->request->nr_sectors & 1)) {
printk(KERN_ERR "sd: Bad block number requested");
return 0;
} else {
block = block >> 1;
this_count = this_count >> 1;
}
}
if (sdp->sector_size == 2048) {
if ((block & 3) || (SCpnt->request->nr_sectors & 3)) {
printk(KERN_ERR "sd: Bad block number requested");
return 0;
} else {
block = block >> 2;
this_count = this_count >> 2;
}
}
if (sdp->sector_size == 4096) {
if ((block & 7) || (SCpnt->request->nr_sectors & 7)) {
printk(KERN_ERR "sd: Bad block number requested");
return 0;
} else {
block = block >> 3;
this_count = this_count >> 3;
}
}
if (rq_data_dir(SCpnt->request) == WRITE) {
if (!sdp->writeable) {
return 0;
}
SCpnt->cmnd[0] = WRITE_6;
SCpnt->sc_data_direction = DMA_TO_DEVICE;
} else if (rq_data_dir(SCpnt->request) == READ) {
SCpnt->cmnd[0] = READ_6;
SCpnt->sc_data_direction = DMA_FROM_DEVICE;
} else {
printk(KERN_ERR "sd: Unknown command %lx\n",
SCpnt->request->flags);
/* overkill panic("Unknown sd command %lx\n", SCpnt->request->flags); */
return 0;
}
SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
disk->disk_name, (rq_data_dir(SCpnt->request) == WRITE) ?
"writing" : "reading", this_count, SCpnt->request->nr_sectors));
SCpnt->cmnd[1] = 0;
if (block > 0xffffffff) {
SCpnt->cmnd[0] += READ_16 - READ_6;
SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
SCpnt->cmnd[9] = (unsigned char) block & 0xff;
SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
} else if ((this_count > 0xff) || (block > 0x1fffff) ||
static int sd_init_command(Scsi_Cmnd * SCpnt)
{
int dev, block, this_count;
struct hd_struct *ppnt;
Scsi_Disk *dpnt;
#if CONFIG_SCSI_LOGGING
char nbuff[6];
#endif
ppnt = &sd_gendisks[SD_MAJOR_IDX(SCpnt->request.rq_dev)].part[MINOR(SCpnt->request.rq_dev)];
dev = DEVICE_NR(SCpnt->request.rq_dev);
block = SCpnt->request.sector;
this_count = SCpnt->request_bufflen >> 9;
SCSI_LOG_HLQUEUE(1, printk("Doing sd request, dev = 0x%x, block = %d\n",
SCpnt->request.rq_dev, block));
dpnt = &rscsi_disks[dev];
if (dev >= sd_template.dev_max ||
!dpnt->device ||
!dpnt->device->online ||
block + SCpnt->request.nr_sectors > ppnt->nr_sects) {
SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", SCpnt->request.nr_sectors));
SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
return 0;
}
block += ppnt->start_sect;
if (dpnt->device->changed) {
/*
* quietly refuse to do anything to a changed disc until the changed
* bit has been reset
*/
/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
return 0;
}
SCSI_LOG_HLQUEUE(2, sd_devname(dev, nbuff));
SCSI_LOG_HLQUEUE(2, printk("%s : real dev = /dev/%d, block = %d\n",
nbuff, dev, block));
/*
* If we have a 1K hardware sectorsize, prevent access to single
* 512 byte sectors. In theory we could handle this - in fact
* the scsi cdrom driver must be able to handle this because
* we typically use 1K blocksizes, and cdroms typically have
* 2K hardware sectorsizes. Of course, things are simpler
* with the cdrom, since it is read-only. For performance
* reasons, the filesystems should be able to handle this
* and not force the scsi disk driver to use bounce buffers
* for this.
*/
if (dpnt->device->sector_size == 1024) {
if ((block & 1) || (SCpnt->request.nr_sectors & 1)) {
printk("sd.c:Bad block number requested");
return 0;
} else {
block = block >> 1;
this_count = this_count >> 1;
}
}
if (dpnt->device->sector_size == 2048) {
if ((block & 3) || (SCpnt->request.nr_sectors & 3)) {
printk("sd.c:Bad block number requested");
return 0;
} else {
block = block >> 2;
this_count = this_count >> 2;
}
}
if (dpnt->device->sector_size == 4096) {
if ((block & 7) || (SCpnt->request.nr_sectors & 7)) {
printk("sd.c:Bad block number requested");
return 0;
} else {
block = block >> 3;
this_count = this_count >> 3;
}
}
switch (SCpnt->request.cmd) {
case WRITE:
if (!dpnt->device->writeable) {
return 0;
}
SCpnt->cmnd[0] = WRITE_6;
SCpnt->sc_data_direction = SCSI_DATA_WRITE;
break;
case READ:
SCpnt->cmnd[0] = READ_6;
SCpnt->sc_data_direction = SCSI_DATA_READ;
break;
default:
panic("Unknown sd command %d\n", SCpnt->request.cmd);
}
SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
nbuff,
(SCpnt->request.cmd == WRITE) ? "writing" : "reading",
this_count, SCpnt->request.nr_sectors));
SCpnt->cmnd[1] = (SCpnt->device->scsi_level <= SCSI_2) ?
((SCpnt->lun << 5) & 0xe0) : 0;
if (((this_count > 0xff) || (block > 0x1fffff)) || SCpnt->device->ten) {
if (this_count > 0xffff)
this_count = 0xffff;
SCpnt->cmnd[0] += READ_10 - READ_6;
SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
SCpnt->cmnd[5] = (unsigned char) block & 0xff;
SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
} else {
if (this_count > 0xff)
