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/drivers/scsi/scsi_transport_srp.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 383 lines | 266 code | 69 blank | 48 comment | 27 complexity | cb8d32fffc75c81d385ffb6408b3959f MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
  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
 35struct 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
 43struct srp_internal {
 44	struct scsi_transport_template t;
 45	struct srp_function_template *f;
 46
 47	struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
 48
 49	struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
 50	struct 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(dev) dev_to_rport((dev)->parent)
 58
 59static int srp_host_setup(struct transport_container *tc, struct device *dev,
 60			  struct 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
 69static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
 70			       NULL, NULL);
 71
 72static 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] = dev_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
102static ssize_t
103show_srp_rport_id(struct device *dev, struct device_attribute *attr,
104		  char *buf)
105{
106	struct srp_rport *rport = transport_class_to_srp_rport(dev);
107	return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport));
108}
109
110static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
111
112static const struct {
113	u32 value;
114	char *name;
115} srp_rport_role_names[] = {
116	{SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
117	{SRP_RPORT_ROLE_TARGET, "SRP Target"},
118};
119
120static ssize_t
121show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
122		     char *buf)
123{
124	struct srp_rport *rport = transport_class_to_srp_rport(dev);
125	int i;
126	char *name = NULL;
127
128	for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
129		if (srp_rport_role_names[i].value == rport->roles) {
130			name = srp_rport_role_names[i].name;
131			break;
132		}
133	return sprintf(buf, "%s\n", name ? : "unknown");
134}
135
136static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
137
138static void srp_rport_release(struct device *dev)
139{
140	struct srp_rport *rport = dev_to_rport(dev);
141
142	put_device(dev->parent);
143	kfree(rport);
144}
145
146static int scsi_is_srp_rport(const struct device *dev)
147{
148	return dev->release == srp_rport_release;
149}
150
151static int srp_rport_match(struct attribute_container *cont,
152			   struct device *dev)
153{
154	struct Scsi_Host *shost;
155	struct srp_internal *i;
156
157	if (!scsi_is_srp_rport(dev))
158		return 0;
159
160	shost = dev_to_shost(dev->parent);
161	if (!shost->transportt)
162		return 0;
163	if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
164		return 0;
165
166	i = to_srp_internal(shost->transportt);
167	return &i->rport_attr_cont.ac == cont;
168}
169
170static int srp_host_match(struct attribute_container *cont, struct device *dev)
171{
172	struct Scsi_Host *shost;
173	struct srp_internal *i;
174
175	if (!scsi_is_host_device(dev))
176		return 0;
177
178	shost = dev_to_shost(dev);
179	if (!shost->transportt)
180		return 0;
181	if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
182		return 0;
183
184	i = to_srp_internal(shost->transportt);
185	return &i->t.host_attrs.ac == cont;
186}
187
188/**
189 * srp_rport_add - add a SRP remote port to the device hierarchy
190 * @shost:	scsi host the remote port is connected to.
191 * @ids:	The port id for the remote port.
192 *
193 * Publishes a port to the rest of the system.
194 */
195struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
196				struct srp_rport_identifiers *ids)
197{
198	struct srp_rport *rport;
199	struct device *parent = &shost->shost_gendev;
200	int id, ret;
201
202	rport = kzalloc(sizeof(*rport), GFP_KERNEL);
203	if (!rport)
204		return ERR_PTR(-ENOMEM);
205
206	device_initialize(&rport->dev);
207
208	rport->dev.parent = get_device(parent);
209	rport->dev.release = srp_rport_release;
210
211	memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
212	rport->roles = ids->roles;
213
214	id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
215	dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id);
216
217	transport_setup_device(&rport->dev);
218
219	ret = device_add(&rport->dev);
220	if (ret) {
221		transport_destroy_device(&rport->dev);
222		put_device(&rport->dev);
223		return ERR_PTR(ret);
224	}
225
226	if (shost->active_mode & MODE_TARGET &&
227	    ids->roles == SRP_RPORT_ROLE_INITIATOR) {
228		ret = srp_tgt_it_nexus_create(shost, (unsigned long)rport,
229					      rport->port_id);
230		if (ret) {
231			device_del(&rport->dev);
232			transport_destroy_device(&rport->dev);
233			put_device(&rport->dev);
234			return ERR_PTR(ret);
235		}
236	}
237
238	transport_add_device(&rport->dev);
239	transport_configure_device(&rport->dev);
240
241	return rport;
242}
243EXPORT_SYMBOL_GPL(srp_rport_add);
244
245/**
246 * srp_rport_del  -  remove a SRP remote port
247 * @rport:	SRP remote port to remove
248 *
249 * Removes the specified SRP remote port.
250 */
251void srp_rport_del(struct srp_rport *rport)
252{
253	struct device *dev = &rport->dev;
254	struct Scsi_Host *shost = dev_to_shost(dev->parent);
255
256	if (shost->active_mode & MODE_TARGET &&
257	    rport->roles == SRP_RPORT_ROLE_INITIATOR)
258		srp_tgt_it_nexus_destroy(shost, (unsigned long)rport);
259
260	transport_remove_device(dev);
261	device_del(dev);
262	transport_destroy_device(dev);
263	put_device(dev);
264}
265EXPORT_SYMBOL_GPL(srp_rport_del);
266
267static int do_srp_rport_del(struct device *dev, void *data)
268{
269	if (scsi_is_srp_rport(dev))
270		srp_rport_del(dev_to_rport(dev));
271	return 0;
272}
273
274/**
275 * srp_remove_host  -  tear down a Scsi_Host's SRP data structures
276 * @shost:	Scsi Host that is torn down
277 *
278 * Removes all SRP remote ports for a given Scsi_Host.
279 * Must be called just before scsi_remove_host for SRP HBAs.
280 */
281void srp_remove_host(struct Scsi_Host *shost)
282{
283	device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
284}
285EXPORT_SYMBOL_GPL(srp_remove_host);
286
287static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id,
288				 int result)
289{
290	struct srp_internal *i = to_srp_internal(shost->transportt);
291	return i->f->tsk_mgmt_response(shost, nexus, tm_id, result);
292}
293
294static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result)
295{
296	struct srp_internal *i = to_srp_internal(shost->transportt);
297	return i->f->it_nexus_response(shost, nexus, result);
298}
299
300/**
301 * srp_attach_transport  -  instantiate SRP transport template
302 * @ft:		SRP transport class function template
303 */
304struct scsi_transport_template *
305srp_attach_transport(struct srp_function_template *ft)
306{
307	int count;
308	struct srp_internal *i;
309
310	i = kzalloc(sizeof(*i), GFP_KERNEL);
311	if (!i)
312		return NULL;
313
314	i->t.tsk_mgmt_response = srp_tsk_mgmt_response;
315	i->t.it_nexus_response = srp_it_nexus_response;
316
317	i->t.host_size = sizeof(struct srp_host_attrs);
318	i->t.host_attrs.ac.attrs = &i->host_attrs[0];
319	i->t.host_attrs.ac.class = &srp_host_class.class;
320	i->t.host_attrs.ac.match = srp_host_match;
321	i->host_attrs[0] = NULL;
322	transport_container_register(&i->t.host_attrs);
323
324	i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
325	i->rport_attr_cont.ac.class = &srp_rport_class.class;
326	i->rport_attr_cont.ac.match = srp_rport_match;
327	transport_container_register(&i->rport_attr_cont);
328
329	count = 0;
330	SETUP_RPORT_ATTRIBUTE_RD(port_id);
331	SETUP_RPORT_ATTRIBUTE_RD(roles);
332	i->rport_attrs[count] = NULL;
333
334	i->f = ft;
335
336	return &i->t;
337}
338EXPORT_SYMBOL_GPL(srp_attach_transport);
339
340/**
341 * srp_release_transport  -  release SRP transport template instance
342 * @t:		transport template instance
343 */
344void srp_release_transport(struct scsi_transport_template *t)
345{
346	struct srp_internal *i = to_srp_internal(t);
347
348	transport_container_unregister(&i->t.host_attrs);
349	transport_container_unregister(&i->rport_attr_cont);
350
351	kfree(i);
352}
353EXPORT_SYMBOL_GPL(srp_release_transport);
354
355static __init int srp_transport_init(void)
356{
357	int ret;
358
359	ret = transport_class_register(&srp_host_class);
360	if (ret)
361		return ret;
362	ret = transport_class_register(&srp_rport_class);
363	if (ret)
364		goto unregister_host_class;
365
366	return 0;
367unregister_host_class:
368	transport_class_unregister(&srp_host_class);
369	return ret;
370}
371
372static void __exit srp_transport_exit(void)
373{
374	transport_class_unregister(&srp_host_class);
375	transport_class_unregister(&srp_rport_class);
376}
377
378MODULE_AUTHOR("FUJITA Tomonori");
379MODULE_DESCRIPTION("SRP Transport Attributes");
380MODULE_LICENSE("GPL");
381
382module_init(srp_transport_init);
383module_exit(srp_transport_exit);