1 /*
2  * Basic HP/COMPAQ MSA 1000 support. This is only needed if your HW cannot be
3  * upgraded.
4  *
5  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
6  * Copyright (C) 2006 Mike Christie
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2, or (at your option)
11  * any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; see the file COPYING.  If not, write to
20  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 
23 #include <scsi/scsi.h>
24 #include <scsi/scsi_dbg.h>
25 #include <scsi/scsi_eh.h>
26 #include <scsi/scsi_dh.h>
27 
28 #define HP_SW_NAME	"hp_sw"
29 
30 #define HP_SW_TIMEOUT (60 * HZ)
31 #define HP_SW_RETRIES 3
32 
33 struct hp_sw_dh_data {
34 	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
35 	int retries;
36 };
37 
38 static inline struct hp_sw_dh_data *get_hp_sw_data(struct scsi_device *sdev)
39 {
40 	struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
41 	BUG_ON(scsi_dh_data == NULL);
42 	return ((struct hp_sw_dh_data *) scsi_dh_data->buf);
43 }
44 
45 static int hp_sw_done(struct scsi_device *sdev)
46 {
47 	struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
48 	struct scsi_sense_hdr sshdr;
49 	int rc;
50 
51 	sdev_printk(KERN_INFO, sdev, "hp_sw_done\n");
52 
53 	rc = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
54 	if (!rc)
55 		goto done;
56 	switch (sshdr.sense_key) {
57 	case NOT_READY:
58 		if ((sshdr.asc == 0x04) && (sshdr.ascq == 3)) {
59 			rc = SCSI_DH_RETRY;
60 			h->retries++;
61 			break;
62 		}
63 		/* fall through */
64 	default:
65 		h->retries++;
66 		rc = SCSI_DH_IMM_RETRY;
67 	}
68 
69 done:
70 	if (rc == SCSI_DH_OK || rc == SCSI_DH_IO)
71 		h->retries = 0;
72 	else if (h->retries > HP_SW_RETRIES) {
73 		h->retries = 0;
74 		rc = SCSI_DH_IO;
75 	}
76 	return rc;
77 }
78 
79 static int hp_sw_activate(struct scsi_device *sdev)
80 {
81 	struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
82 	struct request *req;
83 	int ret = SCSI_DH_RES_TEMP_UNAVAIL;
84 
85 	req = blk_get_request(sdev->request_queue, WRITE, GFP_ATOMIC);
86 	if (!req)
87 		goto done;
88 
89 	sdev_printk(KERN_INFO, sdev, "sending START_STOP.");
90 
91 	req->cmd_type = REQ_TYPE_BLOCK_PC;
92 	req->cmd_flags |= REQ_FAILFAST;
93 	req->cmd_len = COMMAND_SIZE(START_STOP);
94 	memset(req->cmd, 0, MAX_COMMAND_SIZE);
95 	req->cmd[0] = START_STOP;
96 	req->cmd[4] = 1;	/* Start spin cycle */
97 	req->timeout = HP_SW_TIMEOUT;
98 	req->sense = h->sense;
99 	memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
100 	req->sense_len = 0;
101 
102 	ret = blk_execute_rq(req->q, NULL, req, 1);
103 	if (!ret) /* SUCCESS */
104 		ret = hp_sw_done(sdev);
105 	else
106 		ret = SCSI_DH_IO;
107 done:
108 	return ret;
109 }
110 
111 static const struct {
112 	char *vendor;
113 	char *model;
114 } hp_sw_dh_data_list[] = {
115 	{"COMPAQ", "MSA"},
116 	{"HP", "HSV"},
117 	{"DEC", "HSG80"},
118 	{NULL, NULL},
119 };
120 
121 static int hp_sw_bus_notify(struct notifier_block *, unsigned long, void *);
122 
123 static struct scsi_device_handler hp_sw_dh = {
124 	.name		= HP_SW_NAME,
125 	.module		= THIS_MODULE,
126 	.nb.notifier_call = hp_sw_bus_notify,
127 	.activate	= hp_sw_activate,
128 };
129 
130 static int hp_sw_bus_notify(struct notifier_block *nb,
131 			    unsigned long action, void *data)
132 {
133 	struct device *dev = data;
134 	struct scsi_device *sdev;
135 	struct scsi_dh_data *scsi_dh_data;
136 	int i, found = 0;
137 	unsigned long flags;
138 
139 	if (!scsi_is_sdev_device(dev))
140 		return 0;
141 
142 	sdev = to_scsi_device(dev);
143 
144 	if (action == BUS_NOTIFY_ADD_DEVICE) {
145 		for (i = 0; hp_sw_dh_data_list[i].vendor; i++) {
146 			if (!strncmp(sdev->vendor, hp_sw_dh_data_list[i].vendor,
147 				     strlen(hp_sw_dh_data_list[i].vendor)) &&
148 			    !strncmp(sdev->model, hp_sw_dh_data_list[i].model,
149 				     strlen(hp_sw_dh_data_list[i].model))) {
150 				found = 1;
151 				break;
152 			}
153 		}
154 		if (!found)
155 			goto out;
156 
157 		scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
158 				+ sizeof(struct hp_sw_dh_data) , GFP_KERNEL);
159 		if (!scsi_dh_data) {
160 			sdev_printk(KERN_ERR, sdev, "Attach Failed %s.\n",
161 				    HP_SW_NAME);
162 			goto out;
163 		}
164 
165 		scsi_dh_data->scsi_dh = &hp_sw_dh;
166 		spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
167 		sdev->scsi_dh_data = scsi_dh_data;
168 		spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
169 		try_module_get(THIS_MODULE);
170 
171 		sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", HP_SW_NAME);
172 	} else if (action == BUS_NOTIFY_DEL_DEVICE) {
173 		if (sdev->scsi_dh_data == NULL ||
174 				sdev->scsi_dh_data->scsi_dh != &hp_sw_dh)
175 			goto out;
176 
177 		spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
178 		scsi_dh_data = sdev->scsi_dh_data;
179 		sdev->scsi_dh_data = NULL;
180 		spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
181 		module_put(THIS_MODULE);
182 
183 		sdev_printk(KERN_NOTICE, sdev, "Dettached %s.\n", HP_SW_NAME);
184 
185 		kfree(scsi_dh_data);
186 	}
187 
188 out:
189 	return 0;
190 }
191 
192 static int __init hp_sw_init(void)
193 {
194 	return scsi_register_device_handler(&hp_sw_dh);
195 }
196 
197 static void __exit hp_sw_exit(void)
198 {
199 	scsi_unregister_device_handler(&hp_sw_dh);
200 }
201 
202 module_init(hp_sw_init);
203 module_exit(hp_sw_exit);
204 
205 MODULE_DESCRIPTION("HP MSA 1000");
206 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu");
207 MODULE_LICENSE("GPL");
208