[SCSI] scsi_dh: add EMC Clariion device handler

This adds support for EMC Clariions. This patch has the features that currently exists in mainline and advanced features from Ed's patches. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: add EMC Clariion device handler
This adds support for EMC Clariions. This patch has the features that currently exists in mainline and advanced features from Ed's patches. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Chandra Seetharaman · James Bottomley
1 parent f6dd337ee4
Showing 3 changed files with 506 additions and 0 deletions Side-by-side Diff
drivers/scsi/device_handler/Kconfig
drivers/scsi/device_handler/Makefile
drivers/scsi/device_handler/scsi_dh_emc.c
@@ -24,4 +24,10 @@
 	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.
+
+config SCSI_DH_EMC
+	tristate "EMC CLARiiON Device Handler"
+	depends on SCSI_DH
+	help
+	If you have a EMC CLARiiON select y. Otherwise, say N.
@@ -4,4 +4,5 @@
 obj-$(CONFIG_SCSI_DH)		+= scsi_dh.o
 obj-$(CONFIG_SCSI_DH_RDAC)	+= scsi_dh_rdac.o
 obj-$(CONFIG_SCSI_DH_HP_SW)	+= scsi_dh_hp_sw.o
+obj-$(CONFIG_SCSI_DH_EMC)	+= scsi_dh_emc.o
+/*
+ * Target driver for EMC CLARiiON AX/CX-series hardware.
+ * Based on code from Lars Marowsky-Bree <lmb@suse.de>
+ * and Ed Goggin <egoggin@emc.com>.
+ *
+ * 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_eh.h>
+#include <scsi/scsi_dh.h>
+#include <scsi/scsi_device.h>
+
+#define CLARIION_NAME			"emc_clariion"
+
+#define CLARIION_TRESPASS_PAGE		0x22
+#define CLARIION_BUFFER_SIZE		0x80
+#define CLARIION_TIMEOUT		(60 * HZ)
+#define CLARIION_RETRIES		3
+#define CLARIION_UNBOUND_LU		-1
+
+static unsigned char long_trespass[] = {
+	0, 0, 0, 0,
+	CLARIION_TRESPASS_PAGE,	/* Page code */
+	0x09,			/* Page length - 2 */
+	0x81,			/* Trespass code + Honor reservation bit */
+	0xff, 0xff,		/* Trespass target */
+	0, 0, 0, 0, 0, 0	/* Reserved bytes / unknown */
+};
+
+static unsigned char long_trespass_hr[] = {
+	0, 0, 0, 0,
+	CLARIION_TRESPASS_PAGE,	/* Page code */
+	0x09,			/* Page length - 2 */
+	0x01,			/* Trespass code + Honor reservation bit */
+	0xff, 0xff,		/* Trespass target */
+	0, 0, 0, 0, 0, 0	/* Reserved bytes / unknown */
+};
+
+static unsigned char short_trespass[] = {
+	0, 0, 0, 0,
+	CLARIION_TRESPASS_PAGE,	/* Page code */
+	0x02,			/* Page length - 2 */
+	0x81,			/* Trespass code + Honor reservation bit */
+	0xff,			/* Trespass target */
+};
+
+static unsigned char short_trespass_hr[] = {
+	0, 0, 0, 0,
+	CLARIION_TRESPASS_PAGE,	/* Page code */
+	0x02,			/* Page length - 2 */
+	0x01,			/* Trespass code + Honor reservation bit */
+	0xff,			/* Trespass target */
+};
+
+struct clariion_dh_data {
+	/*
+	 * Use short trespass command (FC-series) or the long version
+	 * (default for AX/CX CLARiiON arrays).
+	 */
+	unsigned short_trespass;
+	/*
+	 * Whether or not (default) to honor SCSI reservations when
+	 * initiating a switch-over.
+	 */
+	unsigned hr;
+	/* I/O buffer for both MODE_SELECT and INQUIRY commands. */
+	char buffer[CLARIION_BUFFER_SIZE];
+	/*
+	 * SCSI sense buffer for commands -- assumes serial issuance
+	 * and completion sequence of all commands for same multipath.
+	 */
+	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
+	/* which SP (A=0,B=1,UNBOUND=-1) is dflt SP for path's mapped dev */
+	int default_sp;
+	/* which SP (A=0,B=1,UNBOUND=-1) is active for path's mapped dev */
+	int current_sp;
+};
+
+static inline struct clariion_dh_data
+			*get_clariion_data(struct scsi_device *sdev)
+{
+	struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
+	BUG_ON(scsi_dh_data == NULL);
+	return ((struct clariion_dh_data *) scsi_dh_data->buf);
+}
+
+/*
+ * Parse MODE_SELECT cmd reply.
+ */
+static int trespass_endio(struct scsi_device *sdev, int result)
+{
+	int err = SCSI_DH_OK;
+	struct scsi_sense_hdr sshdr;
+	struct clariion_dh_data *csdev = get_clariion_data(sdev);
+	char *sense = csdev->sense;
+
+	if (status_byte(result) == CHECK_CONDITION &&
+	    scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)) {
+		sdev_printk(KERN_ERR, sdev, "Found valid sense data 0x%2x, "
+			    "0x%2x, 0x%2x while sending CLARiiON trespass "
+			    "command.\n", sshdr.sense_key, sshdr.asc,
+			     sshdr.ascq);
+
+		if ((sshdr.sense_key == 0x05) && (sshdr.asc == 0x04) &&
+		     (sshdr.ascq == 0x00)) {
+			/*
+			 * Array based copy in progress -- do not send
+			 * mode_select or copy will be aborted mid-stream.
+			 */
+			sdev_printk(KERN_INFO, sdev, "Array Based Copy in "
+				    "progress while sending CLARiiON trespass "
+				    "command.\n");
+			err = SCSI_DH_DEV_TEMP_BUSY;
+		} else if ((sshdr.sense_key == 0x02) && (sshdr.asc == 0x04) &&
+			    (sshdr.ascq == 0x03)) {
+			/*
+			 * LUN Not Ready - Manual Intervention Required
+			 * indicates in-progress ucode upgrade (NDU).
+			 */
+			sdev_printk(KERN_INFO, sdev, "Detected in-progress "
+				    "ucode upgrade NDU operation while sending "
+				    "CLARiiON trespass command.\n");
+			err = SCSI_DH_DEV_TEMP_BUSY;
+		} else
+			err = SCSI_DH_DEV_FAILED;
+	} else if (result) {
+		sdev_printk(KERN_ERR, sdev, "Error 0x%x while sending "
+			    "CLARiiON trespass command.\n", result);
+		err = SCSI_DH_IO;
+	}
+
+	return err;
+}
+
+static int parse_sp_info_reply(struct scsi_device *sdev, int result,
+		int *default_sp, int *current_sp, int *new_current_sp)
+{
+	int err = SCSI_DH_OK;
+	struct clariion_dh_data *csdev = get_clariion_data(sdev);
+
+	if (result == 0) {
+		/* check for in-progress ucode upgrade (NDU) */
+		if (csdev->buffer[48] != 0) {
+			sdev_printk(KERN_NOTICE, sdev, "Detected in-progress "
+			       "ucode upgrade NDU operation while finding "
+			       "current active SP.");
+			err = SCSI_DH_DEV_TEMP_BUSY;
+		} else {
+			*default_sp = csdev->buffer[5];
+
+			if (csdev->buffer[4] == 2)
+				/* SP for path is current */
+				*current_sp = csdev->buffer[8];
+			else {
+				if (csdev->buffer[4] == 1)
+					/* SP for this path is NOT current */
+					if (csdev->buffer[8] == 0)
+						*current_sp = 1;
+					else
+						*current_sp = 0;
+				else
+					/* unbound LU or LUNZ */
+					*current_sp = CLARIION_UNBOUND_LU;
+			}
+			*new_current_sp =  csdev->buffer[8];
+		}
+	} else {
+		struct scsi_sense_hdr sshdr;
+
+		err = SCSI_DH_IO;
+
+		if (scsi_normalize_sense(csdev->sense, SCSI_SENSE_BUFFERSIZE,
+							   &sshdr))
+			sdev_printk(KERN_ERR, sdev, "Found valid sense data "
+			      "0x%2x, 0x%2x, 0x%2x while finding current "
+			      "active SP.", sshdr.sense_key, sshdr.asc,
+			      sshdr.ascq);
+		else
+			sdev_printk(KERN_ERR, sdev, "Error 0x%x finding "
+			      "current active SP.", result);
+	}
+
+	return err;
+}
+
+static int sp_info_endio(struct scsi_device *sdev, int result,
+					int mode_select_sent, int *done)
+{
+	struct clariion_dh_data *csdev = get_clariion_data(sdev);
+	int err_flags, default_sp, current_sp, new_current_sp;
+
+	err_flags = parse_sp_info_reply(sdev, result, &default_sp,
+					     &current_sp, &new_current_sp);
+
+	if (err_flags != SCSI_DH_OK)
+		goto done;
+
+	if (mode_select_sent) {
+		csdev->default_sp = default_sp;
+		csdev->current_sp = current_sp;
+	} else {
+		/*
+		 * Issue the actual module_selec request IFF either
+		 * (1) we do not know the identity of the current SP OR
+		 * (2) what we think we know is actually correct.
+		 */
+		if ((current_sp != CLARIION_UNBOUND_LU) &&
+		    (new_current_sp != current_sp)) {
+
+			csdev->default_sp = default_sp;
+			csdev->current_sp = current_sp;
+
+			sdev_printk(KERN_INFO, sdev, "Ignoring path group "
+			       "switch-over command for CLARiiON SP%s since "
+			       " mapped device is already initialized.",
+			       current_sp ? "B" : "A");
+			if (done)
+				*done = 1; /* as good as doing it */
+		}
+	}
+done:
+	return err_flags;
+}
+
+/*
+* Get block request for REQ_BLOCK_PC command issued to path.  Currently
+* limited to MODE_SELECT (trespass) and INQUIRY (VPD page 0xC0) commands.
+*
+* Uses data and sense buffers in hardware handler context structure and
+* assumes serial servicing of commands, both issuance and completion.
+*/
+static struct request *get_req(struct scsi_device *sdev, int cmd)
+{
+	struct clariion_dh_data *csdev = get_clariion_data(sdev);
+	struct request *rq;
+	unsigned char *page22;
+	int len = 0;
+
+	rq = blk_get_request(sdev->request_queue,
+			(cmd == MODE_SELECT) ? WRITE : READ, GFP_ATOMIC);
+	if (!rq) {
+		sdev_printk(KERN_INFO, sdev, "get_req: blk_get_request failed");
+		return NULL;
+	}
+
+	memset(&rq->cmd, 0, BLK_MAX_CDB);
+	rq->cmd[0] = cmd;
+	rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
+
+	switch (cmd) {
+	case MODE_SELECT:
+		if (csdev->short_trespass) {
+			page22 = csdev->hr ? short_trespass_hr : short_trespass;
+			len = sizeof(short_trespass);
+		} else {
+			page22 = csdev->hr ? long_trespass_hr : long_trespass;
+			len = sizeof(long_trespass);
+		}
+		/*
+		 * Can't DMA from kernel BSS -- must copy selected trespass
+		 * command mode page contents to context buffer which is
+		 * allocated by kmalloc.
+		 */
+		BUG_ON((len > CLARIION_BUFFER_SIZE));
+		memcpy(csdev->buffer, page22, len);
+		rq->cmd_flags |= REQ_RW;
+		rq->cmd[1] = 0x10;
+		break;
+	case INQUIRY:
+		rq->cmd[1] = 0x1;
+		rq->cmd[2] = 0xC0;
+		len = CLARIION_BUFFER_SIZE;
+		memset(csdev->buffer, 0, CLARIION_BUFFER_SIZE);
+		break;
+	default:
+		BUG_ON(1);
+		break;
+	}
+
+	rq->cmd[4] = len;
+	rq->cmd_type = REQ_TYPE_BLOCK_PC;
+	rq->cmd_flags |= REQ_FAILFAST;
+	rq->timeout = CLARIION_TIMEOUT;
+	rq->retries = CLARIION_RETRIES;
+
+	rq->sense = csdev->sense;
+	memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
+	rq->sense_len = 0;
+
+	if (blk_rq_map_kern(sdev->request_queue, rq, csdev->buffer,
+							len, GFP_ATOMIC)) {
+		__blk_put_request(rq->q, rq);
+		return NULL;
+	}
+
+	return rq;
+}
+
+static int send_cmd(struct scsi_device *sdev, int cmd)
+{
+	struct request *rq = get_req(sdev, cmd);
+
+	if (!rq)
+		return SCSI_DH_RES_TEMP_UNAVAIL;
+
+	return blk_execute_rq(sdev->request_queue, NULL, rq, 1);
+}
+
+static int clariion_activate(struct scsi_device *sdev)
+{
+	int result, done = 0;
+
+	result = send_cmd(sdev, INQUIRY);
+	result = sp_info_endio(sdev, result, 0, &done);
+	if (result || done)
+		goto done;
+
+	result = send_cmd(sdev, MODE_SELECT);
+	result = trespass_endio(sdev, result);
+	if (result)
+		goto done;
+
+	result = send_cmd(sdev, INQUIRY);
+	result = sp_info_endio(sdev, result, 1, NULL);
+done:
+	return result;
+}
+
+static int clariion_check_sense(struct scsi_device *sdev,
+				struct scsi_sense_hdr *sense_hdr)
+{
+	switch (sense_hdr->sense_key) {
+	case NOT_READY:
+		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
+			/*
+			 * LUN Not Ready - Manual Intervention Required
+			 * indicates this is a passive path.
+			 *
+			 * FIXME: However, if this is seen and EVPD C0
+			 * indicates that this is due to a NDU in
+			 * progress, we should set FAIL_PATH too.
+			 * This indicates we might have to do a SCSI
+			 * inquiry in the end_io path. Ugh.
+			 *
+			 * Can return FAILED only when we want the error
+			 * recovery process to kick in.
+			 */
+			return SUCCESS;
+		break;
+	case ILLEGAL_REQUEST:
+		if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
+			/*
+			 * An array based copy is in progress. Do not
+			 * fail the path, do not bypass to another PG,
+			 * do not retry. Fail the IO immediately.
+			 * (Actually this is the same conclusion as in
+			 * the default handler, but lets make sure.)
+			 *
+			 * Can return FAILED only when we want the error
+			 * recovery process to kick in.
+			 */
+			return SUCCESS;
+		break;
+	case UNIT_ATTENTION:
+		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
+			/*
+			 * Unit Attention Code. This is the first IO
+			 * to the new path, so just retry.
+			 */
+			return NEEDS_RETRY;
+		break;
+	}
+
+	/* success just means we do not care what scsi-ml does */
+	return SUCCESS;
+}
+
+static const struct {
+	char *vendor;
+	char *model;
+} clariion_dev_list[] = {
+	{"DGC", "RAID"},
+	{"DGC", "DISK"},
+	{NULL, NULL},
+};
+
+static int clariion_bus_notify(struct notifier_block *, unsigned long, void *);
+
+static struct scsi_device_handler clariion_dh = {
+	.name		= CLARIION_NAME,
+	.module		= THIS_MODULE,
+	.nb.notifier_call = clariion_bus_notify,
+	.check_sense	= clariion_check_sense,
+	.activate	= clariion_activate,
+};
+
+/*
+ * TODO: need some interface so we can set trespass values
+ */
+static int clariion_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;
+	struct clariion_dh_data *h;
+	int i, found = 0;
+	unsigned long flags;
+
+	if (action == BUS_NOTIFY_ADD_DEVICE) {
+		for (i = 0; clariion_dev_list[i].vendor; i++) {
+			if (!strncmp(sdev->vendor, clariion_dev_list[i].vendor,
+				     strlen(clariion_dev_list[i].vendor)) &&
+			    !strncmp(sdev->model, clariion_dev_list[i].model,
+				     strlen(clariion_dev_list[i].model))) {
+				found = 1;
+				break;
+			}
+		}
+		if (!found)
+			goto out;
+
+		scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
+				+ sizeof(*h) , GFP_KERNEL);
+		if (!scsi_dh_data) {
+			sdev_printk(KERN_ERR, sdev, "Attach failed %s.\n",
+				    CLARIION_NAME);
+			goto out;
+		}
+
+		scsi_dh_data->scsi_dh = &clariion_dh;
+		h = (struct clariion_dh_data *) scsi_dh_data->buf;
+		h->default_sp = CLARIION_UNBOUND_LU;
+		h->current_sp = CLARIION_UNBOUND_LU;
+
+		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);
+
+		sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", CLARIION_NAME);
+		try_module_get(THIS_MODULE);
+
+	} else if (action == BUS_NOTIFY_DEL_DEVICE) {
+		if (sdev->scsi_dh_data == NULL ||
+				sdev->scsi_dh_data->scsi_dh != &clariion_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);
+
+		sdev_printk(KERN_NOTICE, sdev, "Dettached %s.\n",
+			    CLARIION_NAME);
+
+		kfree(scsi_dh_data);
+		module_put(THIS_MODULE);
+	}
+
+out:
+	return 0;
+}
+
+static int __init clariion_init(void)
+{
+	int r;
+
+	r = scsi_register_device_handler(&clariion_dh);
+	if (r != 0)
+		printk(KERN_ERR "Failed to register scsi device handler.");
+	return r;
+}
+
+static void __exit clariion_exit(void)
+{
+	scsi_unregister_device_handler(&clariion_dh);
+}
+
+module_init(clariion_init);
+module_exit(clariion_exit);
+
+MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
+MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
+MODULE_LICENSE("GPL");
...	...	@@ -24,4 +24,10 @@
24	24	If you have a HP/COMPAQ MSA device that requires START_STOP to
25	25	be sent to start it and cannot upgrade the firmware then select y.
26	26	Otherwise, say N.
	27	+
	28	+config SCSI_DH_EMC
	29	+ tristate "EMC CLARiiON Device Handler"
	30	+ depends on SCSI_DH
	31	+ help
	32	+ If you have a EMC CLARiiON select y. Otherwise, say N.
...	...	@@ -4,4 +4,5 @@
4	4	obj-$(CONFIG_SCSI_DH) += scsi_dh.o
5	5	obj-$(CONFIG_SCSI_DH_RDAC) += scsi_dh_rdac.o
6	6	obj-$(CONFIG_SCSI_DH_HP_SW) += scsi_dh_hp_sw.o
	7	+obj-$(CONFIG_SCSI_DH_EMC) += scsi_dh_emc.o
	1	+/*
	2	+ * Target driver for EMC CLARiiON AX/CX-series hardware.
	3	+ * Based on code from Lars Marowsky-Bree <lmb@suse.de>
	4	+ * and Ed Goggin <egoggin@emc.com>.
	5	+ *
	6	+ * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
	7	+ * Copyright (C) 2006 Mike Christie
	8	+ *
	9	+ * This program is free software; you can redistribute it and/or modify
	10	+ * it under the terms of the GNU General Public License as published by
	11	+ * the Free Software Foundation; either version 2, or (at your option)
	12	+ * any later version.
	13	+ *
	14	+ * This program is distributed in the hope that it will be useful,
	15	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	+ * GNU General Public License for more details.
	18	+ *
	19	+ * You should have received a copy of the GNU General Public License
	20	+ * along with this program; see the file COPYING. If not, write to
	21	+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
	22	+ */
	23	+#include <scsi/scsi.h>
	24	+#include <scsi/scsi_eh.h>
	25	+#include <scsi/scsi_dh.h>
	26	+#include <scsi/scsi_device.h>
	27	+
	28	+#define CLARIION_NAME "emc_clariion"
	29	+
	30	+#define CLARIION_TRESPASS_PAGE 0x22
	31	+#define CLARIION_BUFFER_SIZE 0x80
	32	+#define CLARIION_TIMEOUT (60 * HZ)
	33	+#define CLARIION_RETRIES 3
	34	+#define CLARIION_UNBOUND_LU -1
	35	+
	36	+static unsigned char long_trespass[] = {
	37	+ 0, 0, 0, 0,
	38	+ CLARIION_TRESPASS_PAGE, /* Page code */
	39	+ 0x09, /* Page length - 2 */
	40	+ 0x81, /* Trespass code + Honor reservation bit */
	41	+ 0xff, 0xff, /* Trespass target */
	42	+ 0, 0, 0, 0, 0, 0 /* Reserved bytes / unknown */
	43	+};
	44	+
	45	+static unsigned char long_trespass_hr[] = {
	46	+ 0, 0, 0, 0,
	47	+ CLARIION_TRESPASS_PAGE, /* Page code */
	48	+ 0x09, /* Page length - 2 */
	49	+ 0x01, /* Trespass code + Honor reservation bit */
	50	+ 0xff, 0xff, /* Trespass target */
	51	+ 0, 0, 0, 0, 0, 0 /* Reserved bytes / unknown */
	52	+};
	53	+
	54	+static unsigned char short_trespass[] = {
	55	+ 0, 0, 0, 0,
	56	+ CLARIION_TRESPASS_PAGE, /* Page code */
	57	+ 0x02, /* Page length - 2 */
	58	+ 0x81, /* Trespass code + Honor reservation bit */
	59	+ 0xff, /* Trespass target */
	60	+};
	61	+
	62	+static unsigned char short_trespass_hr[] = {
	63	+ 0, 0, 0, 0,
	64	+ CLARIION_TRESPASS_PAGE, /* Page code */
	65	+ 0x02, /* Page length - 2 */
	66	+ 0x01, /* Trespass code + Honor reservation bit */
	67	+ 0xff, /* Trespass target */
	68	+};
	69	+
	70	+struct clariion_dh_data {
	71	+ /*
	72	+ * Use short trespass command (FC-series) or the long version
	73	+ * (default for AX/CX CLARiiON arrays).
	74	+ */
	75	+ unsigned short_trespass;
	76	+ /*
	77	+ * Whether or not (default) to honor SCSI reservations when
	78	+ * initiating a switch-over.
	79	+ */
	80	+ unsigned hr;
	81	+ /* I/O buffer for both MODE_SELECT and INQUIRY commands. */
	82	+ char buffer[CLARIION_BUFFER_SIZE];
	83	+ /*
	84	+ * SCSI sense buffer for commands -- assumes serial issuance
	85	+ * and completion sequence of all commands for same multipath.
	86	+ */
	87	+ unsigned char sense[SCSI_SENSE_BUFFERSIZE];
	88	+ /* which SP (A=0,B=1,UNBOUND=-1) is dflt SP for path's mapped dev */
	89	+ int default_sp;
	90	+ /* which SP (A=0,B=1,UNBOUND=-1) is active for path's mapped dev */
	91	+ int current_sp;
	92	+};
	93	+
	94	+static inline struct clariion_dh_data
	95	+ get_clariion_data(struct scsi_device sdev)
	96	+{
	97	+ struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
	98	+ BUG_ON(scsi_dh_data == NULL);
	99	+ return ((struct clariion_dh_data *) scsi_dh_data->buf);
	100	+}
	101	+
	102	+/*
	103	+ * Parse MODE_SELECT cmd reply.
	104	+ */
	105	+static int trespass_endio(struct scsi_device *sdev, int result)
	106	+{
	107	+ int err = SCSI_DH_OK;
	108	+ struct scsi_sense_hdr sshdr;
	109	+ struct clariion_dh_data *csdev = get_clariion_data(sdev);
	110	+ char *sense = csdev->sense;
	111	+
	112	+ if (status_byte(result) == CHECK_CONDITION &&
	113	+ scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)) {
	114	+ sdev_printk(KERN_ERR, sdev, "Found valid sense data 0x%2x, "
	115	+ "0x%2x, 0x%2x while sending CLARiiON trespass "
	116	+ "command.\n", sshdr.sense_key, sshdr.asc,
	117	+ sshdr.ascq);
	118	+
	119	+ if ((sshdr.sense_key == 0x05) && (sshdr.asc == 0x04) &&
	120	+ (sshdr.ascq == 0x00)) {
	121	+ /*
	122	+ * Array based copy in progress -- do not send
	123	+ * mode_select or copy will be aborted mid-stream.
	124	+ */
	125	+ sdev_printk(KERN_INFO, sdev, "Array Based Copy in "
	126	+ "progress while sending CLARiiON trespass "
	127	+ "command.\n");
	128	+ err = SCSI_DH_DEV_TEMP_BUSY;
	129	+ } else if ((sshdr.sense_key == 0x02) && (sshdr.asc == 0x04) &&
	130	+ (sshdr.ascq == 0x03)) {
	131	+ /*
	132	+ * LUN Not Ready - Manual Intervention Required
	133	+ * indicates in-progress ucode upgrade (NDU).
	134	+ */
	135	+ sdev_printk(KERN_INFO, sdev, "Detected in-progress "
	136	+ "ucode upgrade NDU operation while sending "
	137	+ "CLARiiON trespass command.\n");
	138	+ err = SCSI_DH_DEV_TEMP_BUSY;
	139	+ } else
	140	+ err = SCSI_DH_DEV_FAILED;
	141	+ } else if (result) {
	142	+ sdev_printk(KERN_ERR, sdev, "Error 0x%x while sending "
	143	+ "CLARiiON trespass command.\n", result);
	144	+ err = SCSI_DH_IO;
	145	+ }
	146	+
	147	+ return err;
	148	+}
	149	+
	150	+static int parse_sp_info_reply(struct scsi_device *sdev, int result,
	151	+ int default_sp, int current_sp, int *new_current_sp)
	152	+{
	153	+ int err = SCSI_DH_OK;
	154	+ struct clariion_dh_data *csdev = get_clariion_data(sdev);
	155	+
	156	+ if (result == 0) {
	157	+ /* check for in-progress ucode upgrade (NDU) */
	158	+ if (csdev->buffer[48] != 0) {
	159	+ sdev_printk(KERN_NOTICE, sdev, "Detected in-progress "
	160	+ "ucode upgrade NDU operation while finding "
	161	+ "current active SP.");
	162	+ err = SCSI_DH_DEV_TEMP_BUSY;
	163	+ } else {
	164	+ *default_sp = csdev->buffer[5];
	165	+
	166	+ if (csdev->buffer[4] == 2)
	167	+ /* SP for path is current */
	168	+ *current_sp = csdev->buffer[8];
	169	+ else {
	170	+ if (csdev->buffer[4] == 1)
	171	+ /* SP for this path is NOT current */
	172	+ if (csdev->buffer[8] == 0)
	173	+ *current_sp = 1;
	174	+ else
	175	+ *current_sp = 0;
	176	+ else
	177	+ /* unbound LU or LUNZ */
	178	+ *current_sp = CLARIION_UNBOUND_LU;
	179	+ }
	180	+ *new_current_sp = csdev->buffer[8];
	181	+ }
	182	+ } else {
	183	+ struct scsi_sense_hdr sshdr;
	184	+
	185	+ err = SCSI_DH_IO;
	186	+
	187	+ if (scsi_normalize_sense(csdev->sense, SCSI_SENSE_BUFFERSIZE,
	188	+ &sshdr))
	189	+ sdev_printk(KERN_ERR, sdev, "Found valid sense data "
	190	+ "0x%2x, 0x%2x, 0x%2x while finding current "
	191	+ "active SP.", sshdr.sense_key, sshdr.asc,
	192	+ sshdr.ascq);
	193	+ else
	194	+ sdev_printk(KERN_ERR, sdev, "Error 0x%x finding "
	195	+ "current active SP.", result);
	196	+ }
	197	+
	198	+ return err;
	199	+}
	200	+
	201	+static int sp_info_endio(struct scsi_device *sdev, int result,
	202	+ int mode_select_sent, int *done)
	203	+{
	204	+ struct clariion_dh_data *csdev = get_clariion_data(sdev);
	205	+ int err_flags, default_sp, current_sp, new_current_sp;
	206	+
	207	+ err_flags = parse_sp_info_reply(sdev, result, &default_sp,
	208	+ &current_sp, &new_current_sp);
	209	+
	210	+ if (err_flags != SCSI_DH_OK)
	211	+ goto done;
	212	+
	213	+ if (mode_select_sent) {
	214	+ csdev->default_sp = default_sp;
	215	+ csdev->current_sp = current_sp;
	216	+ } else {
	217	+ /*
	218	+ * Issue the actual module_selec request IFF either
	219	+ * (1) we do not know the identity of the current SP OR
	220	+ * (2) what we think we know is actually correct.
	221	+ */
	222	+ if ((current_sp != CLARIION_UNBOUND_LU) &&
	223	+ (new_current_sp != current_sp)) {
	224	+
	225	+ csdev->default_sp = default_sp;
	226	+ csdev->current_sp = current_sp;
	227	+
	228	+ sdev_printk(KERN_INFO, sdev, "Ignoring path group "
	229	+ "switch-over command for CLARiiON SP%s since "
	230	+ " mapped device is already initialized.",
	231	+ current_sp ? "B" : "A");
	232	+ if (done)
	233	+ done = 1; / as good as doing it */
	234	+ }
	235	+ }
	236	+done:
	237	+ return err_flags;
	238	+}
	239	+
	240	+/*
	241	+* Get block request for REQ_BLOCK_PC command issued to path. Currently
	242	+* limited to MODE_SELECT (trespass) and INQUIRY (VPD page 0xC0) commands.
	243	+*
	244	+* Uses data and sense buffers in hardware handler context structure and
	245	+* assumes serial servicing of commands, both issuance and completion.
	246	+*/
	247	+static struct request get_req(struct scsi_device sdev, int cmd)
	248	+{
	249	+ struct clariion_dh_data *csdev = get_clariion_data(sdev);
	250	+ struct request *rq;
	251	+ unsigned char *page22;
	252	+ int len = 0;
	253	+
	254	+ rq = blk_get_request(sdev->request_queue,
	255	+ (cmd == MODE_SELECT) ? WRITE : READ, GFP_ATOMIC);
	256	+ if (!rq) {
	257	+ sdev_printk(KERN_INFO, sdev, "get_req: blk_get_request failed");
	258	+ return NULL;
	259	+ }
	260	+
	261	+ memset(&rq->cmd, 0, BLK_MAX_CDB);
	262	+ rq->cmd[0] = cmd;
	263	+ rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
	264	+
	265	+ switch (cmd) {
	266	+ case MODE_SELECT:
	267	+ if (csdev->short_trespass) {
	268	+ page22 = csdev->hr ? short_trespass_hr : short_trespass;
	269	+ len = sizeof(short_trespass);
	270	+ } else {
	271	+ page22 = csdev->hr ? long_trespass_hr : long_trespass;
	272	+ len = sizeof(long_trespass);
	273	+ }
	274	+ /*
	275	+ * Can't DMA from kernel BSS -- must copy selected trespass
	276	+ * command mode page contents to context buffer which is
	277	+ * allocated by kmalloc.
	278	+ */
	279	+ BUG_ON((len > CLARIION_BUFFER_SIZE));
	280	+ memcpy(csdev->buffer, page22, len);
	281	+ rq->cmd_flags \|= REQ_RW;
	282	+ rq->cmd[1] = 0x10;
	283	+ break;
	284	+ case INQUIRY:
	285	+ rq->cmd[1] = 0x1;
	286	+ rq->cmd[2] = 0xC0;
	287	+ len = CLARIION_BUFFER_SIZE;
	288	+ memset(csdev->buffer, 0, CLARIION_BUFFER_SIZE);
	289	+ break;
	290	+ default:
	291	+ BUG_ON(1);
	292	+ break;
	293	+ }
	294	+
	295	+ rq->cmd[4] = len;
	296	+ rq->cmd_type = REQ_TYPE_BLOCK_PC;
	297	+ rq->cmd_flags \|= REQ_FAILFAST;
	298	+ rq->timeout = CLARIION_TIMEOUT;
	299	+ rq->retries = CLARIION_RETRIES;
	300	+
	301	+ rq->sense = csdev->sense;
	302	+ memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
	303	+ rq->sense_len = 0;
	304	+
	305	+ if (blk_rq_map_kern(sdev->request_queue, rq, csdev->buffer,
	306	+ len, GFP_ATOMIC)) {
	307	+ __blk_put_request(rq->q, rq);
	308	+ return NULL;
	309	+ }
	310	+
	311	+ return rq;
	312	+}
	313	+
	314	+static int send_cmd(struct scsi_device *sdev, int cmd)
	315	+{
	316	+ struct request *rq = get_req(sdev, cmd);
	317	+
	318	+ if (!rq)
	319	+ return SCSI_DH_RES_TEMP_UNAVAIL;
	320	+
	321	+ return blk_execute_rq(sdev->request_queue, NULL, rq, 1);
	322	+}
	323	+
	324	+static int clariion_activate(struct scsi_device *sdev)
	325	+{
	326	+ int result, done = 0;
	327	+
	328	+ result = send_cmd(sdev, INQUIRY);
	329	+ result = sp_info_endio(sdev, result, 0, &done);
	330	+ if (result \|\| done)
	331	+ goto done;
	332	+
	333	+ result = send_cmd(sdev, MODE_SELECT);
	334	+ result = trespass_endio(sdev, result);
	335	+ if (result)
	336	+ goto done;
	337	+
	338	+ result = send_cmd(sdev, INQUIRY);
	339	+ result = sp_info_endio(sdev, result, 1, NULL);
	340	+done:
	341	+ return result;
	342	+}
	343	+
	344	+static int clariion_check_sense(struct scsi_device *sdev,
	345	+ struct scsi_sense_hdr *sense_hdr)
	346	+{
	347	+ switch (sense_hdr->sense_key) {
	348	+ case NOT_READY:
	349	+ if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
	350	+ /*
	351	+ * LUN Not Ready - Manual Intervention Required
	352	+ * indicates this is a passive path.
	353	+ *
	354	+ * FIXME: However, if this is seen and EVPD C0
	355	+ * indicates that this is due to a NDU in
	356	+ * progress, we should set FAIL_PATH too.
	357	+ * This indicates we might have to do a SCSI
	358	+ * inquiry in the end_io path. Ugh.
	359	+ *
	360	+ * Can return FAILED only when we want the error
	361	+ * recovery process to kick in.
	362	+ */
	363	+ return SUCCESS;
	364	+ break;
	365	+ case ILLEGAL_REQUEST:
	366	+ if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
	367	+ /*
	368	+ * An array based copy is in progress. Do not
	369	+ * fail the path, do not bypass to another PG,
	370	+ * do not retry. Fail the IO immediately.
	371	+ * (Actually this is the same conclusion as in
	372	+ * the default handler, but lets make sure.)
	373	+ *
	374	+ * Can return FAILED only when we want the error
	375	+ * recovery process to kick in.
	376	+ */
	377	+ return SUCCESS;
	378	+ break;
	379	+ case UNIT_ATTENTION:
	380	+ if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
	381	+ /*
	382	+ * Unit Attention Code. This is the first IO
	383	+ * to the new path, so just retry.
	384	+ */
	385	+ return NEEDS_RETRY;
	386	+ break;
	387	+ }
	388	+
	389	+ /* success just means we do not care what scsi-ml does */
	390	+ return SUCCESS;
	391	+}
	392	+
	393	+static const struct {
	394	+ char *vendor;
	395	+ char *model;
	396	+} clariion_dev_list[] = {
	397	+ {"DGC", "RAID"},
	398	+ {"DGC", "DISK"},
	399	+ {NULL, NULL},
	400	+};
	401	+
	402	+static int clariion_bus_notify(struct notifier_block , unsigned long, void );
	403	+
	404	+static struct scsi_device_handler clariion_dh = {
	405	+ .name = CLARIION_NAME,
	406	+ .module = THIS_MODULE,
	407	+ .nb.notifier_call = clariion_bus_notify,
	408	+ .check_sense = clariion_check_sense,
	409	+ .activate = clariion_activate,
	410	+};
	411	+
	412	+/*
	413	+ * TODO: need some interface so we can set trespass values
	414	+ */
	415	+static int clariion_bus_notify(struct notifier_block *nb,
	416	+ unsigned long action, void *data)
	417	+{
	418	+ struct device *dev = data;
	419	+ struct scsi_device *sdev = to_scsi_device(dev);
	420	+ struct scsi_dh_data *scsi_dh_data;
	421	+ struct clariion_dh_data *h;
	422	+ int i, found = 0;
	423	+ unsigned long flags;
	424	+
	425	+ if (action == BUS_NOTIFY_ADD_DEVICE) {
	426	+ for (i = 0; clariion_dev_list[i].vendor; i++) {
	427	+ if (!strncmp(sdev->vendor, clariion_dev_list[i].vendor,
	428	+ strlen(clariion_dev_list[i].vendor)) &&
	429	+ !strncmp(sdev->model, clariion_dev_list[i].model,
	430	+ strlen(clariion_dev_list[i].model))) {
	431	+ found = 1;
	432	+ break;
	433	+ }
	434	+ }
	435	+ if (!found)
	436	+ goto out;
	437	+
	438	+ scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
	439	+ + sizeof(*h) , GFP_KERNEL);
	440	+ if (!scsi_dh_data) {
	441	+ sdev_printk(KERN_ERR, sdev, "Attach failed %s.\n",
	442	+ CLARIION_NAME);
	443	+ goto out;
	444	+ }
	445	+
	446	+ scsi_dh_data->scsi_dh = &clariion_dh;
	447	+ h = (struct clariion_dh_data *) scsi_dh_data->buf;
	448	+ h->default_sp = CLARIION_UNBOUND_LU;
	449	+ h->current_sp = CLARIION_UNBOUND_LU;
	450	+
	451	+ spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
	452	+ sdev->scsi_dh_data = scsi_dh_data;
	453	+ spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
	454	+
	455	+ sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", CLARIION_NAME);
	456	+ try_module_get(THIS_MODULE);
	457	+
	458	+ } else if (action == BUS_NOTIFY_DEL_DEVICE) {
	459	+ if (sdev->scsi_dh_data == NULL \|\|
	460	+ sdev->scsi_dh_data->scsi_dh != &clariion_dh)
	461	+ goto out;
	462	+
	463	+ spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
	464	+ scsi_dh_data = sdev->scsi_dh_data;
	465	+ sdev->scsi_dh_data = NULL;
	466	+ spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
	467	+
	468	+ sdev_printk(KERN_NOTICE, sdev, "Dettached %s.\n",
	469	+ CLARIION_NAME);
	470	+
	471	+ kfree(scsi_dh_data);
	472	+ module_put(THIS_MODULE);
	473	+ }
	474	+
	475	+out:
	476	+ return 0;
	477	+}
	478	+
	479	+static int __init clariion_init(void)
	480	+{
	481	+ int r;
	482	+
	483	+ r = scsi_register_device_handler(&clariion_dh);
	484	+ if (r != 0)
	485	+ printk(KERN_ERR "Failed to register scsi device handler.");
	486	+ return r;
	487	+}
	488	+
	489	+static void __exit clariion_exit(void)
	490	+{
	491	+ scsi_unregister_device_handler(&clariion_dh);
	492	+}
	493	+
	494	+module_init(clariion_init);
	495	+module_exit(clariion_exit);
	496	+
	497	+MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
	498	+MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
	499	+MODULE_LICENSE("GPL");