272 lines
6.5 KiB
C
272 lines
6.5 KiB
C
/*
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* Basic HP/COMPAQ MSA 1000 support. This is only needed if your HW cannot be
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* upgraded.
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*
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* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
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* Copyright (C) 2006 Mike Christie
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* Copyright (C) 2008 Hannes Reinecke <hare@suse.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_dbg.h>
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#include <scsi/scsi_eh.h>
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#include <scsi/scsi_dh.h>
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#define HP_SW_NAME "hp_sw"
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#define HP_SW_TIMEOUT (60 * HZ)
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#define HP_SW_RETRIES 3
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#define HP_SW_PATH_UNINITIALIZED -1
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#define HP_SW_PATH_ACTIVE 0
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#define HP_SW_PATH_PASSIVE 1
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struct hp_sw_dh_data {
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int path_state;
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int retries;
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int retry_cnt;
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struct scsi_device *sdev;
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};
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static int hp_sw_start_stop(struct hp_sw_dh_data *);
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/*
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* tur_done - Handle TEST UNIT READY return status
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* @sdev: sdev the command has been sent to
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* @errors: blk error code
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*
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* Returns SCSI_DH_DEV_OFFLINED if the sdev is on the passive path
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*/
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static int tur_done(struct scsi_device *sdev, struct hp_sw_dh_data *h,
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struct scsi_sense_hdr *sshdr)
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{
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int ret = SCSI_DH_IO;
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switch (sshdr->sense_key) {
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case UNIT_ATTENTION:
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ret = SCSI_DH_IMM_RETRY;
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break;
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case NOT_READY:
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if (sshdr->asc == 0x04 && sshdr->ascq == 2) {
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/*
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* LUN not ready - Initialization command required
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*
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* This is the passive path
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*/
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h->path_state = HP_SW_PATH_PASSIVE;
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ret = SCSI_DH_OK;
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break;
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}
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/* Fallthrough */
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default:
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sdev_printk(KERN_WARNING, sdev,
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"%s: sending tur failed, sense %x/%x/%x\n",
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HP_SW_NAME, sshdr->sense_key, sshdr->asc,
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sshdr->ascq);
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break;
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}
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return ret;
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}
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/*
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* hp_sw_tur - Send TEST UNIT READY
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* @sdev: sdev command should be sent to
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*
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* Use the TEST UNIT READY command to determine
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* the path state.
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*/
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static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
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{
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unsigned char cmd[6] = { TEST_UNIT_READY };
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struct scsi_sense_hdr sshdr;
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int ret = SCSI_DH_OK, res;
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u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
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REQ_FAILFAST_DRIVER;
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retry:
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res = scsi_execute(sdev, cmd, DMA_NONE, NULL, 0, NULL, &sshdr,
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HP_SW_TIMEOUT, HP_SW_RETRIES, req_flags, 0, NULL);
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if (res) {
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if (scsi_sense_valid(&sshdr))
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ret = tur_done(sdev, h, &sshdr);
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else {
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sdev_printk(KERN_WARNING, sdev,
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"%s: sending tur failed with %x\n",
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HP_SW_NAME, res);
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ret = SCSI_DH_IO;
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}
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} else {
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h->path_state = HP_SW_PATH_ACTIVE;
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ret = SCSI_DH_OK;
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}
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if (ret == SCSI_DH_IMM_RETRY)
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goto retry;
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return ret;
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}
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/*
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* hp_sw_start_stop - Send START STOP UNIT command
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* @sdev: sdev command should be sent to
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*
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* Sending START STOP UNIT activates the SP.
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*/
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static int hp_sw_start_stop(struct hp_sw_dh_data *h)
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{
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unsigned char cmd[6] = { START_STOP, 0, 0, 0, 1, 0 };
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struct scsi_sense_hdr sshdr;
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struct scsi_device *sdev = h->sdev;
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int res, rc = SCSI_DH_OK;
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int retry_cnt = HP_SW_RETRIES;
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u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
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REQ_FAILFAST_DRIVER;
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retry:
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res = scsi_execute(sdev, cmd, DMA_NONE, NULL, 0, NULL, &sshdr,
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HP_SW_TIMEOUT, HP_SW_RETRIES, req_flags, 0, NULL);
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if (res) {
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if (!scsi_sense_valid(&sshdr)) {
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sdev_printk(KERN_WARNING, sdev,
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"%s: sending start_stop_unit failed, "
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"no sense available\n", HP_SW_NAME);
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return SCSI_DH_IO;
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}
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switch (sshdr.sense_key) {
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case NOT_READY:
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if (sshdr.asc == 0x04 && sshdr.ascq == 3) {
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/*
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* LUN not ready - manual intervention required
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*
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* Switch-over in progress, retry.
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*/
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if (--retry_cnt)
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goto retry;
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rc = SCSI_DH_RETRY;
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break;
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}
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/* fall through */
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default:
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sdev_printk(KERN_WARNING, sdev,
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"%s: sending start_stop_unit failed, "
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"sense %x/%x/%x\n", HP_SW_NAME,
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sshdr.sense_key, sshdr.asc, sshdr.ascq);
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rc = SCSI_DH_IO;
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}
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}
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return rc;
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}
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static int hp_sw_prep_fn(struct scsi_device *sdev, struct request *req)
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{
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struct hp_sw_dh_data *h = sdev->handler_data;
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int ret = BLKPREP_OK;
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if (h->path_state != HP_SW_PATH_ACTIVE) {
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ret = BLKPREP_KILL;
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req->rq_flags |= RQF_QUIET;
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}
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return ret;
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}
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/*
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* hp_sw_activate - Activate a path
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* @sdev: sdev on the path to be activated
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*
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* The HP Active/Passive firmware is pretty simple;
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* the passive path reports NOT READY with sense codes
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* 0x04/0x02; a START STOP UNIT command will then
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* activate the passive path (and deactivate the
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* previously active one).
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*/
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static int hp_sw_activate(struct scsi_device *sdev,
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activate_complete fn, void *data)
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{
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int ret = SCSI_DH_OK;
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struct hp_sw_dh_data *h = sdev->handler_data;
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ret = hp_sw_tur(sdev, h);
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if (ret == SCSI_DH_OK && h->path_state == HP_SW_PATH_PASSIVE)
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ret = hp_sw_start_stop(h);
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if (fn)
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fn(data, ret);
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return 0;
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}
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static int hp_sw_bus_attach(struct scsi_device *sdev)
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{
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struct hp_sw_dh_data *h;
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int ret;
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h = kzalloc(sizeof(*h), GFP_KERNEL);
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if (!h)
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return -ENOMEM;
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h->path_state = HP_SW_PATH_UNINITIALIZED;
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h->retries = HP_SW_RETRIES;
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h->sdev = sdev;
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ret = hp_sw_tur(sdev, h);
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if (ret != SCSI_DH_OK || h->path_state == HP_SW_PATH_UNINITIALIZED)
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goto failed;
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sdev_printk(KERN_INFO, sdev, "%s: attached to %s path\n",
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HP_SW_NAME, h->path_state == HP_SW_PATH_ACTIVE?
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"active":"passive");
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sdev->handler_data = h;
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return 0;
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failed:
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kfree(h);
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return -EINVAL;
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}
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static void hp_sw_bus_detach( struct scsi_device *sdev )
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{
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kfree(sdev->handler_data);
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sdev->handler_data = NULL;
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}
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static struct scsi_device_handler hp_sw_dh = {
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.name = HP_SW_NAME,
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.module = THIS_MODULE,
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.attach = hp_sw_bus_attach,
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.detach = hp_sw_bus_detach,
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.activate = hp_sw_activate,
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.prep_fn = hp_sw_prep_fn,
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};
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static int __init hp_sw_init(void)
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{
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return scsi_register_device_handler(&hp_sw_dh);
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}
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static void __exit hp_sw_exit(void)
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{
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scsi_unregister_device_handler(&hp_sw_dh);
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}
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module_init(hp_sw_init);
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module_exit(hp_sw_exit);
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MODULE_DESCRIPTION("HP Active/Passive driver");
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MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu");
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MODULE_LICENSE("GPL");
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