[SCSI] scsi_dh: Update hp_sw hardware handler

This patch updates the hp_sw device handler to properly
check the return codes etc.
And adds the 'correct' machine definitions.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 234 insertions, 38 deletions

diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
index 78259bc5dfc..9c7a1f8ebb7 100644
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -4,6 +4,7 @@
  *
  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
  * Copyright (C) 2006 Mike Christie
+ * Copyright (C) 2008 Hannes Reinecke <hare@suse.de>
  *
  * 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
@@ -25,13 +26,18 @@
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_dh.h>
 
-#define HP_SW_NAME      "hp_sw"
+#define HP_SW_NAME                      "hp_sw"
 
-#define HP_SW_TIMEOUT (60 * HZ)
-#define HP_SW_RETRIES 3
+#define HP_SW_TIMEOUT                   (60 * HZ)
+#define HP_SW_RETRIES                   3
+
+#define HP_SW_PATH_UNINITIALIZED        -1
+#define HP_SW_PATH_ACTIVE               0
+#define HP_SW_PATH_PASSIVE              1
 
 struct hp_sw_dh_data {
         unsigned char sense[SCSI_SENSE_BUFFERSIZE];
+        int path_state;
         int retries;
 };
 
@@ -42,51 +48,161 @@ static inline struct hp_sw_dh_data *get_hp_sw_data(struct scsi_device *sdev)
         return ((struct hp_sw_dh_data *) scsi_dh_data->buf);
 }
 
-static int hp_sw_done(struct scsi_device *sdev)
+/*
+ * tur_done - Handle TEST UNIT READY return status
+ * @sdev: sdev the command has been sent to
+ * @errors: blk error code
+ *
+ * Returns SCSI_DH_DEV_OFFLINED if the sdev is on the passive path
+ */
+static int tur_done(struct scsi_device *sdev, unsigned char *sense)
 {
-        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");
+        int ret;
 
-        rc = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
-        if (!rc)
+        ret = scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
+        if (!ret) {
+                sdev_printk(KERN_WARNING, sdev,
+                            "%s: sending tur failed, no sense available\n",
+                            HP_SW_NAME);
+                ret = SCSI_DH_IO;
                 goto done;
+        }
         switch (sshdr.sense_key) {
+        case UNIT_ATTENTION:
+                ret = SCSI_DH_IMM_RETRY;
+                break;
         case NOT_READY:
-                if ((sshdr.asc == 0x04) && (sshdr.ascq == 3)) {
-                        rc = SCSI_DH_RETRY;
-                        h->retries++;
+                if ((sshdr.asc == 0x04) && (sshdr.ascq == 2)) {
+                        /*
+                         * LUN not ready - Initialization command required
+                         *
+                         * This is the passive path
+                         */
+                        ret = SCSI_DH_DEV_OFFLINED;
                         break;
                 }
-                /* fall through */
+                /* Fallthrough */
         default:
-                h->retries++;
-                rc = SCSI_DH_IMM_RETRY;
+                sdev_printk(KERN_WARNING, sdev,
+                           "%s: sending tur failed, sense %x/%x/%x\n",
+                           HP_SW_NAME, sshdr.sense_key, sshdr.asc,
+                           sshdr.ascq);
+                break;
         }
 
 done:
-        if (rc == SCSI_DH_OK || rc == SCSI_DH_IO)
-                h->retries = 0;
-        else if (h->retries > HP_SW_RETRIES) {
-                h->retries = 0;
+        return ret;
+}
+
+/*
+ * hp_sw_tur - Send TEST UNIT READY
+ * @sdev: sdev command should be sent to
+ *
+ * Use the TEST UNIT READY command to determine
+ * the path state.
+ */
+static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
+{
+        struct request *req;
+        int ret;
+
+        req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
+        if (!req)
+                return SCSI_DH_RES_TEMP_UNAVAIL;
+
+        req->cmd_type = REQ_TYPE_BLOCK_PC;
+        req->cmd_flags |= REQ_FAILFAST;
+        req->cmd_len = COMMAND_SIZE(TEST_UNIT_READY);
+        memset(req->cmd, 0, MAX_COMMAND_SIZE);
+        req->cmd[0] = TEST_UNIT_READY;
+        req->timeout = HP_SW_TIMEOUT;
+        req->sense = h->sense;
+        memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
+        req->sense_len = 0;
+
+retry:
+        ret = blk_execute_rq(req->q, NULL, req, 1);
+        if (ret == -EIO) {
+                if (req->sense_len > 0) {
+                        ret = tur_done(sdev, h->sense);
+                } else {
+                        sdev_printk(KERN_WARNING, sdev,
+                                    "%s: sending tur failed with %x\n",
+                                    HP_SW_NAME, req->errors);
+                        ret = SCSI_DH_IO;
+                }
+        } else {
+                h->path_state = HP_SW_PATH_ACTIVE;
+                ret = SCSI_DH_OK;
+        }
+        if (ret == SCSI_DH_IMM_RETRY)
+                goto retry;
+        if (ret == SCSI_DH_DEV_OFFLINED) {
+                h->path_state = HP_SW_PATH_PASSIVE;
+                ret = SCSI_DH_OK;
+        }
+
+        blk_put_request(req);
+
+        return ret;
+}
+
+/*
+ * start_done - Handle START STOP UNIT return status
+ * @sdev: sdev the command has been sent to
+ * @errors: blk error code
+ */
+static int start_done(struct scsi_device *sdev, unsigned char *sense)
+{
+        struct scsi_sense_hdr sshdr;
+        int rc;
+
+        rc = scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
+        if (!rc) {
+                sdev_printk(KERN_WARNING, sdev,
+                            "%s: sending start_stop_unit failed, "
+                            "no sense available\n",
+                            HP_SW_NAME);
+                return SCSI_DH_IO;
+        }
+        switch (sshdr.sense_key) {
+        case NOT_READY:
+                if ((sshdr.asc == 0x04) && (sshdr.ascq == 3)) {
+                        /*
+                         * LUN not ready - manual intervention required
+                         *
+                         * Switch-over in progress, retry.
+                         */
+                        rc = SCSI_DH_RETRY;
+                        break;
+                }
+                /* fall through */
+        default:
+                sdev_printk(KERN_WARNING, sdev,
+                           "%s: sending start_stop_unit failed, sense %x/%x/%x\n",
+                           HP_SW_NAME, sshdr.sense_key, sshdr.asc,
+                           sshdr.ascq);
                 rc = SCSI_DH_IO;
         }
+
         return rc;
 }
 
-static int hp_sw_activate(struct scsi_device *sdev)
+/*
+ * hp_sw_start_stop - Send START STOP UNIT command
+ * @sdev: sdev command should be sent to
+ *
+ * Sending START STOP UNIT activates the SP.
+ */
+static int hp_sw_start_stop(struct scsi_device *sdev, struct hp_sw_dh_data *h)
 {
-        struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
         struct request *req;
-        int ret = SCSI_DH_RES_TEMP_UNAVAIL;
+        int ret, retry;
 
-        req = blk_get_request(sdev->request_queue, WRITE, GFP_ATOMIC);
+        req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
         if (!req)
-                goto done;
-
-        sdev_printk(KERN_INFO, sdev, "sending START_STOP.");
+                return SCSI_DH_RES_TEMP_UNAVAIL;
 
         req->cmd_type = REQ_TYPE_BLOCK_PC;
         req->cmd_flags |= REQ_FAILFAST;
@@ -98,19 +214,78 @@ static int hp_sw_activate(struct scsi_device *sdev)
         req->sense = h->sense;
         memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
         req->sense_len = 0;
+        retry = h->retries;
 
+retry:
         ret = blk_execute_rq(req->q, NULL, req, 1);
-        if (!ret) /* SUCCESS */
-                ret = hp_sw_done(sdev);
-        else
+        if (ret == -EIO) {
+                if (req->sense_len > 0) {
+                        ret = start_done(sdev, h->sense);
+                } else {
+                        sdev_printk(KERN_WARNING, sdev,
+                                    "%s: sending start_stop_unit failed with %x\n",
+                                    HP_SW_NAME, req->errors);
+                        ret = SCSI_DH_IO;
+                }
+        } else
+                ret = SCSI_DH_OK;
+
+        if (ret == SCSI_DH_RETRY) {
+                if (--retry)
+                        goto retry;
                 ret = SCSI_DH_IO;
-done:
+        }
+
+        blk_put_request(req);
+
+        return ret;
+}
+
+static int hp_sw_prep_fn(struct scsi_device *sdev, struct request *req)
+{
+        struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
+        int ret = BLKPREP_OK;
+
+        if (h->path_state != HP_SW_PATH_ACTIVE) {
+                ret = BLKPREP_KILL;
+                req->cmd_flags |= REQ_QUIET;
+        }
+        return ret;
+
+}
+
+/*
+ * hp_sw_activate - Activate a path
+ * @sdev: sdev on the path to be activated
+ *
+ * The HP Active/Passive firmware is pretty simple;
+ * the passive path reports NOT READY with sense codes
+ * 0x04/0x02; a START STOP UNIT command will then
+ * activate the passive path (and deactivate the
+ * previously active one).
+ */
+static int hp_sw_activate(struct scsi_device *sdev)
+{
+        int ret = SCSI_DH_OK;
+        struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
+
+        ret = hp_sw_tur(sdev, h);
+
+        if (ret == SCSI_DH_OK && h->path_state == HP_SW_PATH_PASSIVE) {
+                ret = hp_sw_start_stop(sdev, h);
+                if (ret == SCSI_DH_OK)
+                        sdev_printk(KERN_INFO, sdev,
+                                    "%s: activated path\n",
+                                    HP_SW_NAME);
+        }
+
         return ret;
 }
 
 const struct scsi_dh_devlist hp_sw_dh_data_list[] = {
-        {"COMPAQ", "MSA"},
-        {"HP", "HSV"},
+        {"COMPAQ", "MSA1000 VOLUME"},
+        {"COMPAQ", "HSV110"},
+        {"HP", "HSV100"},
         {"DEC", "HSG80"},
         {NULL, NULL},
 };
@@ -125,30 +300,51 @@ static struct scsi_device_handler hp_sw_dh = {
         .attach         = hp_sw_bus_attach,
         .detach         = hp_sw_bus_detach,
         .activate       = hp_sw_activate,
+        .prep_fn        = hp_sw_prep_fn,
 };
 
 static int hp_sw_bus_attach(struct scsi_device *sdev)
 {
         struct scsi_dh_data *scsi_dh_data;
+        struct hp_sw_dh_data *h;
         unsigned long flags;
+        int ret;
 
         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",
+                sdev_printk(KERN_ERR, sdev, "%s: Attach Failed\n",
                             HP_SW_NAME);
                 return 0;
         }
 
         scsi_dh_data->scsi_dh = &hp_sw_dh;
+        h = (struct hp_sw_dh_data *) scsi_dh_data->buf;
+        h->path_state = HP_SW_PATH_UNINITIALIZED;
+        h->retries = HP_SW_RETRIES;
+
+        ret = hp_sw_tur(sdev, h);
+        if (ret != SCSI_DH_OK || h->path_state == HP_SW_PATH_UNINITIALIZED)
+                goto failed;
+
+        if (!try_module_get(THIS_MODULE))
+                goto failed;
+
         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);
+        sdev_printk(KERN_INFO, sdev, "%s: attached to %s path\n",
+                    HP_SW_NAME, h->path_state == HP_SW_PATH_ACTIVE?
+                    "active":"passive");
 
         return 0;
+
+failed:
+        kfree(scsi_dh_data);
+        sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
+                    HP_SW_NAME);
+        return -EINVAL;
 }
 
 static void hp_sw_bus_detach( struct scsi_device *sdev )
@@ -162,7 +358,7 @@ static void hp_sw_bus_detach( struct scsi_device *sdev )
         spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
         module_put(THIS_MODULE);
 
-        sdev_printk(KERN_NOTICE, sdev, "Detached %s\n", HP_SW_NAME);
+        sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", HP_SW_NAME);
 
         kfree(scsi_dh_data);
 }
@@ -180,6 +376,6 @@ static void __exit hp_sw_exit(void)
 module_init(hp_sw_init);
 module_exit(hp_sw_exit);
 
-MODULE_DESCRIPTION("HP MSA 1000");
+MODULE_DESCRIPTION("HP Active/Passive driver");
 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu");
 MODULE_LICENSE("GPL");