[SCSI] scsi_dh: add hp sw device handler

This patch provides the device handler to support the older hp boxes
which cannot be upgraded.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

3 files changed, 211 insertions, 0 deletions

diff --git a/drivers/scsi/device_handler/Kconfig b/drivers/scsi/device_handler/Kconfig
index 404f37732627..61578d84fa6e 100644
--- a/drivers/scsi/device_handler/Kconfig
+++ b/drivers/scsi/device_handler/Kconfig
@@ -16,3 +16,11 @@ config SCSI_DH_RDAC
         depends on SCSI_DH
         help
         If you have a LSI RDAC select y. Otherwise, say N.
+
+config SCSI_DH_HP_SW
+        tristate "HP/COMPAQ MSA Device Handler"
+        depends on SCSI_DH
+        help
+        If you have a HP/COMPAQ MSA device that requires START_STOP to
+        be sent to start it and cannot upgrade the firmware then select y.
+        Otherwise, say N.
diff --git a/drivers/scsi/device_handler/Makefile b/drivers/scsi/device_handler/Makefile
index 1a42b3498318..08ec1943f19e 100644
--- a/drivers/scsi/device_handler/Makefile
+++ b/drivers/scsi/device_handler/Makefile
@@ -3,3 +3,4 @@
 #
 obj-$(CONFIG_SCSI_DH)           += scsi_dh.o
 obj-$(CONFIG_SCSI_DH_RDAC)      += scsi_dh_rdac.o
+obj-$(CONFIG_SCSI_DH_HP_SW)     += scsi_dh_hp_sw.o
diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
new file mode 100644
index 000000000000..12ceab7b3662
--- /dev/null
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -0,0 +1,202 @@
+/*
+ * Basic HP/COMPAQ MSA 1000 support. This is only needed if your HW cannot be
+ * upgraded.
+ *
+ * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
+ * Copyright (C) 2006 Mike Christie
+ *
+ * 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, 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.  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; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_dh.h>
+
+#define HP_SW_NAME      "hp_sw"
+
+#define HP_SW_TIMEOUT (60 * HZ)
+#define HP_SW_RETRIES 3
+
+struct hp_sw_dh_data {
+        unsigned char sense[SCSI_SENSE_BUFFERSIZE];
+        int retries;
+};
+
+static inline struct hp_sw_dh_data *get_hp_sw_data(struct scsi_device *sdev)
+{
+        struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
+        BUG_ON(scsi_dh_data == NULL);
+        return ((struct hp_sw_dh_data *) scsi_dh_data->buf);
+}
+
+static int hp_sw_done(struct scsi_device *sdev)
+{
+        struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
+        struct scsi_sense_hdr sshdr;
+        int rc;
+
+        sdev_printk(KERN_INFO, sdev, "hp_sw_done\n");
+
+        rc = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
+        if (!rc)
+                goto done;
+        switch (sshdr.sense_key) {
+        case NOT_READY:
+                if ((sshdr.asc == 0x04) && (sshdr.ascq == 3)) {
+                        rc = SCSI_DH_RETRY;
+                        h->retries++;
+                        break;
+                }
+                /* fall through */
+        default:
+                h->retries++;
+                rc = SCSI_DH_IMM_RETRY;
+        }
+
+done:
+        if (rc == SCSI_DH_OK || rc == SCSI_DH_IO)
+                h->retries = 0;
+        else if (h->retries > HP_SW_RETRIES) {
+                h->retries = 0;
+                rc = SCSI_DH_IO;
+        }
+        return rc;
+}
+
+static int hp_sw_activate(struct scsi_device *sdev)
+{
+        struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
+        struct request *req;
+        int ret = SCSI_DH_RES_TEMP_UNAVAIL;
+
+        req = blk_get_request(sdev->request_queue, WRITE, GFP_ATOMIC);
+        if (!req)
+                goto done;
+
+        sdev_printk(KERN_INFO, sdev, "sending START_STOP.");
+
+        req->cmd_type = REQ_TYPE_BLOCK_PC;
+        req->cmd_flags |= REQ_FAILFAST;
+        req->cmd_len = COMMAND_SIZE(START_STOP);
+        memset(req->cmd, 0, MAX_COMMAND_SIZE);
+        req->cmd[0] = START_STOP;
+        req->cmd[4] = 1;        /* Start spin cycle */
+        req->timeout = HP_SW_TIMEOUT;
+        req->sense = h->sense;
+        memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
+        req->sense_len = 0;
+
+        ret = blk_execute_rq(req->q, NULL, req, 1);
+        if (!ret) /* SUCCESS */
+                ret = hp_sw_done(sdev);
+        else
+                ret = SCSI_DH_IO;
+done:
+        return ret;
+}
+
+static const struct {
+        char *vendor;
+        char *model;
+} hp_sw_dh_data_list[] = {
+        {"COMPAQ", "MSA"},
+        {"HP", "HSV"},
+        {"DEC", "HSG80"},
+        {NULL, NULL},
+};
+
+static int hp_sw_bus_notify(struct notifier_block *, unsigned long, void *);
+
+static struct scsi_device_handler hp_sw_dh = {
+        .name           = HP_SW_NAME,
+        .module         = THIS_MODULE,
+        .nb.notifier_call = hp_sw_bus_notify,
+        .activate       = hp_sw_activate,
+};
+
+static int hp_sw_bus_notify(struct notifier_block *nb,
+                            unsigned long action, void *data)
+{
+        struct device *dev = data;
+        struct scsi_device *sdev = to_scsi_device(dev);
+        struct scsi_dh_data *scsi_dh_data;
+        int i, found = 0;
+        unsigned long flags;
+
+        if (action == BUS_NOTIFY_ADD_DEVICE) {
+                for (i = 0; hp_sw_dh_data_list[i].vendor; i++) {
+                        if (!strncmp(sdev->vendor, hp_sw_dh_data_list[i].vendor,
+                                     strlen(hp_sw_dh_data_list[i].vendor)) &&
+                            !strncmp(sdev->model, hp_sw_dh_data_list[i].model,
+                                     strlen(hp_sw_dh_data_list[i].model))) {
+                                found = 1;
+                                break;
+                        }
+                }
+                if (!found)
+                        goto out;
+
+                scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
+                                + sizeof(struct hp_sw_dh_data) , GFP_KERNEL);
+                if (!scsi_dh_data) {
+                        sdev_printk(KERN_ERR, sdev, "Attach Failed %s.\n",
+                                    HP_SW_NAME);
+                        goto out;
+                }
+
+                scsi_dh_data->scsi_dh = &hp_sw_dh;
+                spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
+                sdev->scsi_dh_data = scsi_dh_data;
+                spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
+                try_module_get(THIS_MODULE);
+
+                sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", HP_SW_NAME);
+        } else if (action == BUS_NOTIFY_DEL_DEVICE) {
+                if (sdev->scsi_dh_data == NULL ||
+                                sdev->scsi_dh_data->scsi_dh != &hp_sw_dh)
+                        goto out;
+
+                spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
+                scsi_dh_data = sdev->scsi_dh_data;
+                sdev->scsi_dh_data = NULL;
+                spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
+                module_put(THIS_MODULE);
+
+                sdev_printk(KERN_NOTICE, sdev, "Dettached %s.\n", HP_SW_NAME);
+
+                kfree(scsi_dh_data);
+        }
+
+out:
+        return 0;
+}
+
+static int __init hp_sw_init(void)
+{
+        return scsi_register_device_handler(&hp_sw_dh);
+}
+
+static void __exit hp_sw_exit(void)
+{
+        scsi_unregister_device_handler(&hp_sw_dh);
+}
+
+module_init(hp_sw_init);
+module_exit(hp_sw_exit);
+
+MODULE_DESCRIPTION("HP MSA 1000");
+MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu");
+MODULE_LICENSE("GPL");