diff options
Diffstat (limited to 'drivers/block/cciss_scsi.h')
-rw-r--r-- | drivers/block/cciss_scsi.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/drivers/block/cciss_scsi.h b/drivers/block/cciss_scsi.h new file mode 100644 index 00000000000..5e7e06c07d6 --- /dev/null +++ b/drivers/block/cciss_scsi.h @@ -0,0 +1,79 @@ +/* + * Disk Array driver for Compaq SA53xx Controllers, SCSI Tape module + * Copyright 2001 Compaq Computer Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * Questions/Comments/Bugfixes to iss_storagedev@hp.com + * + */ +#ifdef CONFIG_CISS_SCSI_TAPE +#ifndef _CCISS_SCSI_H_ +#define _CCISS_SCSI_H_ + +#include <scsi/scsicam.h> /* possibly irrelevant, since we don't show disks */ + + // the scsi id of the adapter... +#define SELF_SCSI_ID 15 + // 15 is somewhat arbitrary, since the scsi-2 bus + // that's presented by the driver to the OS is + // fabricated. The "real" scsi-3 bus the + // hardware presents is fabricated too. + // The actual, honest-to-goodness physical + // bus that the devices are attached to is not + // addressible natively, and may in fact turn + // out to be not scsi at all. + +#define SCSI_CCISS_CAN_QUEUE 2 + +/* + +Note, cmd_per_lun could give us some trouble, so I'm setting it very low. +Likewise, SCSI_CCISS_CAN_QUEUE is set very conservatively. + +If the upper scsi layer tries to track how many commands we have +outstanding, it will be operating under the misapprehension that it is +the only one sending us requests. We also have the block interface, +which is where most requests must surely come from, so the upper layer's +notion of how many requests we have outstanding will be wrong most or +all of the time. + +Note, the normal SCSI mid-layer error handling doesn't work well +for this driver because 1) it takes the io_request_lock before +calling error handlers and uses a local variable to store flags, +so the io_request_lock cannot be released and interrupts enabled +inside the error handlers, and, the error handlers cannot poll +for command completion because they might get commands from the +block half of the driver completing, and not know what to do +with them. That's what we get for making a hybrid scsi/block +driver, I suppose. + +*/ + +struct cciss_scsi_dev_t { + int devtype; + int bus, target, lun; /* as presented to the OS */ + unsigned char scsi3addr[8]; /* as presented to the HW */ +}; + +struct cciss_scsi_hba_t { + char *name; + int ndevices; +#define CCISS_MAX_SCSI_DEVS_PER_HBA 16 + struct cciss_scsi_dev_t dev[CCISS_MAX_SCSI_DEVS_PER_HBA]; +}; + +#endif /* _CCISS_SCSI_H_ */ +#endif /* CONFIG_CISS_SCSI_TAPE */ |