| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Disk Array driver for Compaq SA53xx Controllers, SCSI Tape module |
| 3 | * Copyright 2001 Compaq Computer Corporation |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or |
| 13 | * NON INFRINGEMENT. See the GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 18 | * |
| 19 | * Questions/Comments/Bugfixes to iss_storagedev@hp.com |
| 20 | * |
| 21 | */ |
| 22 | #ifdef CONFIG_CISS_SCSI_TAPE |
| 23 | #ifndef _CCISS_SCSI_H_ |
| 24 | #define _CCISS_SCSI_H_ |
| 25 | |
| 26 | #include <scsi/scsicam.h> /* possibly irrelevant, since we don't show disks */ |
| 27 | |
| 28 | // the scsi id of the adapter... |
| 29 | #define SELF_SCSI_ID 15 |
| 30 | // 15 is somewhat arbitrary, since the scsi-2 bus |
| 31 | // that's presented by the driver to the OS is |
| 32 | // fabricated. The "real" scsi-3 bus the |
| 33 | // hardware presents is fabricated too. |
| 34 | // The actual, honest-to-goodness physical |
| 35 | // bus that the devices are attached to is not |
| 36 | // addressible natively, and may in fact turn |
| 37 | // out to be not scsi at all. |
| 38 | |
| 39 | #define SCSI_CCISS_CAN_QUEUE 2 |
| 40 | |
| 41 | /* |
| 42 | |
| 43 | Note, cmd_per_lun could give us some trouble, so I'm setting it very low. |
| 44 | Likewise, SCSI_CCISS_CAN_QUEUE is set very conservatively. |
| 45 | |
| 46 | If the upper scsi layer tries to track how many commands we have |
| 47 | outstanding, it will be operating under the misapprehension that it is |
| 48 | the only one sending us requests. We also have the block interface, |
| 49 | which is where most requests must surely come from, so the upper layer's |
| 50 | notion of how many requests we have outstanding will be wrong most or |
| 51 | all of the time. |
| 52 | |
| 53 | Note, the normal SCSI mid-layer error handling doesn't work well |
| 54 | for this driver because 1) it takes the io_request_lock before |
| 55 | calling error handlers and uses a local variable to store flags, |
| 56 | so the io_request_lock cannot be released and interrupts enabled |
| 57 | inside the error handlers, and, the error handlers cannot poll |
| 58 | for command completion because they might get commands from the |
| 59 | block half of the driver completing, and not know what to do |
| 60 | with them. That's what we get for making a hybrid scsi/block |
| 61 | driver, I suppose. |
| 62 | |
| 63 | */ |
| 64 | |
| 65 | struct cciss_scsi_dev_t { |
| 66 | int devtype; |
| 67 | int bus, target, lun; /* as presented to the OS */ |
| 68 | unsigned char scsi3addr[8]; /* as presented to the HW */ |
| 69 | }; |
| 70 | |
| 71 | struct cciss_scsi_hba_t { |
| 72 | char *name; |
| 73 | int ndevices; |
| 74 | #define CCISS_MAX_SCSI_DEVS_PER_HBA 16 |
| 75 | struct cciss_scsi_dev_t dev[CCISS_MAX_SCSI_DEVS_PER_HBA]; |
| 76 | }; |
| 77 | |
| 78 | #endif /* _CCISS_SCSI_H_ */ |
| 79 | #endif /* CONFIG_CISS_SCSI_TAPE */ |