Pull bugzilla-9194 into release branch
[linux-2.6] / drivers / scsi / scsi_transport_srp.c
1 /*
2  * SCSI RDMA (SRP) transport class
3  *
4  * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation, version 2 of the
9  * License.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19  * 02110-1301 USA
20  */
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/jiffies.h>
24 #include <linux/err.h>
25 #include <linux/slab.h>
26 #include <linux/string.h>
27
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_host.h>
31 #include <scsi/scsi_transport.h>
32 #include <scsi/scsi_transport_srp.h>
33 #include "scsi_transport_srp_internal.h"
34
35 struct srp_host_attrs {
36         atomic_t next_port_id;
37 };
38 #define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
39
40 #define SRP_HOST_ATTRS 0
41 #define SRP_RPORT_ATTRS 2
42
43 struct srp_internal {
44         struct scsi_transport_template t;
45         struct srp_function_template *f;
46
47         struct class_device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
48
49         struct class_device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
50         struct class_device_attribute private_rport_attrs[SRP_RPORT_ATTRS];
51         struct transport_container rport_attr_cont;
52 };
53
54 #define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
55
56 #define dev_to_rport(d) container_of(d, struct srp_rport, dev)
57 #define transport_class_to_srp_rport(cdev) dev_to_rport((cdev)->dev)
58
59 static int srp_host_setup(struct transport_container *tc, struct device *dev,
60                           struct class_device *cdev)
61 {
62         struct Scsi_Host *shost = dev_to_shost(dev);
63         struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
64
65         atomic_set(&srp_host->next_port_id, 0);
66         return 0;
67 }
68
69 static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
70                                NULL, NULL);
71
72 static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
73                                NULL, NULL, NULL);
74
75 #define SETUP_TEMPLATE(attrb, field, perm, test, ro_test, ro_perm)      \
76         i->private_##attrb[count] = class_device_attr_##field;          \
77         i->private_##attrb[count].attr.mode = perm;                     \
78         if (ro_test) {                                                  \
79                 i->private_##attrb[count].attr.mode = ro_perm;          \
80                 i->private_##attrb[count].store = NULL;                 \
81         }                                                               \
82         i->attrb[count] = &i->private_##attrb[count];                   \
83         if (test)                                                       \
84                 count++
85
86 #define SETUP_RPORT_ATTRIBUTE_RD(field)                                 \
87         SETUP_TEMPLATE(rport_attrs, field, S_IRUGO, 1, 0, 0)
88
89 #define SETUP_RPORT_ATTRIBUTE_RW(field)                                 \
90         SETUP_TEMPLATE(rport_attrs, field, S_IRUGO | S_IWUSR,           \
91                        1, 1, S_IRUGO)
92
93 #define SRP_PID(p) \
94         (p)->port_id[0], (p)->port_id[1], (p)->port_id[2], (p)->port_id[3], \
95         (p)->port_id[4], (p)->port_id[5], (p)->port_id[6], (p)->port_id[7], \
96         (p)->port_id[8], (p)->port_id[9], (p)->port_id[10], (p)->port_id[11], \
97         (p)->port_id[12], (p)->port_id[13], (p)->port_id[14], (p)->port_id[15]
98
99 #define SRP_PID_FMT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:" \
100         "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"
101
102 static ssize_t
103 show_srp_rport_id(struct class_device *cdev, char *buf)
104 {
105         struct srp_rport *rport = transport_class_to_srp_rport(cdev);
106         return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport));
107 }
108
109 static CLASS_DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
110
111 static const struct {
112         u32 value;
113         char *name;
114 } srp_rport_role_names[] = {
115         {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
116         {SRP_RPORT_ROLE_TARGET, "SRP Target"},
117 };
118
119 static ssize_t
120 show_srp_rport_roles(struct class_device *cdev, char *buf)
121 {
122         struct srp_rport *rport = transport_class_to_srp_rport(cdev);
123         int i;
124         char *name = NULL;
125
126         for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
127                 if (srp_rport_role_names[i].value == rport->roles) {
128                         name = srp_rport_role_names[i].name;
129                         break;
130                 }
131         return sprintf(buf, "%s\n", name ? : "unknown");
132 }
133
134 static CLASS_DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
135
136 static void srp_rport_release(struct device *dev)
137 {
138         struct srp_rport *rport = dev_to_rport(dev);
139
140         put_device(dev->parent);
141         kfree(rport);
142 }
143
144 static int scsi_is_srp_rport(const struct device *dev)
145 {
146         return dev->release == srp_rport_release;
147 }
148
149 static int srp_rport_match(struct attribute_container *cont,
150                            struct device *dev)
151 {
152         struct Scsi_Host *shost;
153         struct srp_internal *i;
154
155         if (!scsi_is_srp_rport(dev))
156                 return 0;
157
158         shost = dev_to_shost(dev->parent);
159         if (!shost->transportt)
160                 return 0;
161         if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
162                 return 0;
163
164         i = to_srp_internal(shost->transportt);
165         return &i->rport_attr_cont.ac == cont;
166 }
167
168 static int srp_host_match(struct attribute_container *cont, struct device *dev)
169 {
170         struct Scsi_Host *shost;
171         struct srp_internal *i;
172
173         if (!scsi_is_host_device(dev))
174                 return 0;
175
176         shost = dev_to_shost(dev);
177         if (!shost->transportt)
178                 return 0;
179         if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
180                 return 0;
181
182         i = to_srp_internal(shost->transportt);
183         return &i->t.host_attrs.ac == cont;
184 }
185
186 /**
187  * srp_rport_add - add a SRP remote port to the device hierarchy
188  *
189  * @shost:      scsi host the remote port is connected to.
190  * @ids:        The port id for the remote port.
191  *
192  * publishes a port to the rest of the system
193  */
194 struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
195                                 struct srp_rport_identifiers *ids)
196 {
197         struct srp_rport *rport;
198         struct device *parent = &shost->shost_gendev;
199         int id, ret;
200
201         rport = kzalloc(sizeof(*rport), GFP_KERNEL);
202         if (!rport)
203                 return ERR_PTR(-ENOMEM);
204
205         device_initialize(&rport->dev);
206
207         rport->dev.parent = get_device(parent);
208         rport->dev.release = srp_rport_release;
209
210         memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
211         rport->roles = ids->roles;
212
213         id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
214         sprintf(rport->dev.bus_id, "port-%d:%d", shost->host_no, id);
215
216         transport_setup_device(&rport->dev);
217
218         ret = device_add(&rport->dev);
219         if (ret) {
220                 transport_destroy_device(&rport->dev);
221                 put_device(&rport->dev);
222                 return ERR_PTR(ret);
223         }
224
225         if (shost->active_mode & MODE_TARGET &&
226             ids->roles == SRP_RPORT_ROLE_INITIATOR) {
227                 ret = srp_tgt_it_nexus_create(shost, (unsigned long)rport,
228                                               rport->port_id);
229                 if (ret) {
230                         device_del(&rport->dev);
231                         transport_destroy_device(&rport->dev);
232                         put_device(&rport->dev);
233                         return ERR_PTR(ret);
234                 }
235         }
236
237         transport_add_device(&rport->dev);
238         transport_configure_device(&rport->dev);
239
240         return rport;
241 }
242 EXPORT_SYMBOL_GPL(srp_rport_add);
243
244 /**
245  * srp_rport_del  --  remove a SRP remote port
246  * @port:       SRP remote port to remove
247  *
248  * Removes the specified SRP remote port.
249  */
250 void srp_rport_del(struct srp_rport *rport)
251 {
252         struct device *dev = &rport->dev;
253         struct Scsi_Host *shost = dev_to_shost(dev->parent);
254
255         if (shost->active_mode & MODE_TARGET &&
256             rport->roles == SRP_RPORT_ROLE_INITIATOR)
257                 srp_tgt_it_nexus_destroy(shost, (unsigned long)rport);
258
259         transport_remove_device(dev);
260         device_del(dev);
261         transport_destroy_device(dev);
262         put_device(dev);
263 }
264 EXPORT_SYMBOL_GPL(srp_rport_del);
265
266 static int do_srp_rport_del(struct device *dev, void *data)
267 {
268         if (scsi_is_srp_rport(dev))
269                 srp_rport_del(dev_to_rport(dev));
270         return 0;
271 }
272
273 /**
274  * srp_remove_host  --  tear down a Scsi_Host's SRP data structures
275  * @shost:      Scsi Host that is torn down
276  *
277  * Removes all SRP remote ports for a given Scsi_Host.
278  * Must be called just before scsi_remove_host for SRP HBAs.
279  */
280 void srp_remove_host(struct Scsi_Host *shost)
281 {
282         device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
283 }
284 EXPORT_SYMBOL_GPL(srp_remove_host);
285
286 static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id,
287                                  int result)
288 {
289         struct srp_internal *i = to_srp_internal(shost->transportt);
290         return i->f->tsk_mgmt_response(shost, nexus, tm_id, result);
291 }
292
293 static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result)
294 {
295         struct srp_internal *i = to_srp_internal(shost->transportt);
296         return i->f->it_nexus_response(shost, nexus, result);
297 }
298
299 /**
300  * srp_attach_transport  --  instantiate SRP transport template
301  * @ft:         SRP transport class function template
302  */
303 struct scsi_transport_template *
304 srp_attach_transport(struct srp_function_template *ft)
305 {
306         int count;
307         struct srp_internal *i;
308
309         i = kzalloc(sizeof(*i), GFP_KERNEL);
310         if (!i)
311                 return NULL;
312
313         i->t.tsk_mgmt_response = srp_tsk_mgmt_response;
314         i->t.it_nexus_response = srp_it_nexus_response;
315
316         i->t.host_size = sizeof(struct srp_host_attrs);
317         i->t.host_attrs.ac.attrs = &i->host_attrs[0];
318         i->t.host_attrs.ac.class = &srp_host_class.class;
319         i->t.host_attrs.ac.match = srp_host_match;
320         i->host_attrs[0] = NULL;
321         transport_container_register(&i->t.host_attrs);
322
323         i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
324         i->rport_attr_cont.ac.class = &srp_rport_class.class;
325         i->rport_attr_cont.ac.match = srp_rport_match;
326         transport_container_register(&i->rport_attr_cont);
327
328         count = 0;
329         SETUP_RPORT_ATTRIBUTE_RD(port_id);
330         SETUP_RPORT_ATTRIBUTE_RD(roles);
331         i->rport_attrs[count] = NULL;
332
333         i->f = ft;
334
335         return &i->t;
336 }
337 EXPORT_SYMBOL_GPL(srp_attach_transport);
338
339 /**
340  * srp_release_transport  --  release SRP transport template instance
341  * @t:          transport template instance
342  */
343 void srp_release_transport(struct scsi_transport_template *t)
344 {
345         struct srp_internal *i = to_srp_internal(t);
346
347         transport_container_unregister(&i->t.host_attrs);
348         transport_container_unregister(&i->rport_attr_cont);
349
350         kfree(i);
351 }
352 EXPORT_SYMBOL_GPL(srp_release_transport);
353
354 static __init int srp_transport_init(void)
355 {
356         int ret;
357
358         ret = transport_class_register(&srp_host_class);
359         if (ret)
360                 return ret;
361         ret = transport_class_register(&srp_rport_class);
362         if (ret)
363                 goto unregister_host_class;
364
365         return 0;
366 unregister_host_class:
367         transport_class_unregister(&srp_host_class);
368         return ret;
369 }
370
371 static void __exit srp_transport_exit(void)
372 {
373         transport_class_unregister(&srp_host_class);
374         transport_class_unregister(&srp_rport_class);
375 }
376
377 MODULE_AUTHOR("FUJITA Tomonori");
378 MODULE_DESCRIPTION("SRP Transport Attributes");
379 MODULE_LICENSE("GPL");
380
381 module_init(srp_transport_init);
382 module_exit(srp_transport_exit);