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   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/scsi_tgt.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 (ids->roles == SRP_RPORT_ROLE_INITIATOR) {
 226                 ret = scsi_tgt_it_nexus_create(shost, (unsigned long)rport,
 227                                                rport->port_id);
 228                 if (ret) {
 229                         device_del(&rport->dev);
 230                         transport_destroy_device(&rport->dev);
 231                         put_device(&rport->dev);
 232                         return ERR_PTR(ret);
 233                 }
 234         }
 235
 236         transport_add_device(&rport->dev);
 237         transport_configure_device(&rport->dev);
 238
 239         return rport;
 240 }
 241 EXPORT_SYMBOL_GPL(srp_rport_add);
 242
 243 /**
 244  * srp_rport_del  --  remove a SRP remote port
 245  * @port:       SRP remote port to remove
 246  *
 247  * Removes the specified SRP remote port.
 248  */
 249 void srp_rport_del(struct srp_rport *rport)
 250 {
 251         struct device *dev = &rport->dev;
 252
 253         if (rport->roles == SRP_RPORT_ROLE_INITIATOR)
 254                 scsi_tgt_it_nexus_destroy(dev_to_shost(dev->parent),
 255                                           (unsigned long)rport);
 256
 257         transport_remove_device(dev);
 258         device_del(dev);
 259         transport_destroy_device(dev);
 260         put_device(dev);
 261 }
 262 EXPORT_SYMBOL_GPL(srp_rport_del);
 263
 264 static int do_srp_rport_del(struct device *dev, void *data)
 265 {
 266         srp_rport_del(dev_to_rport(dev));
 267         return 0;
 268 }
 269
 270 /**
 271  * srp_remove_host  --  tear down a Scsi_Host's SRP data structures
 272  * @shost:      Scsi Host that is torn down
 273  *
 274  * Removes all SRP remote ports for a given Scsi_Host.
 275  * Must be called just before scsi_remove_host for SRP HBAs.
 276  */
 277 void srp_remove_host(struct Scsi_Host *shost)
 278 {
 279         device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
 280 }
 281 EXPORT_SYMBOL_GPL(srp_remove_host);
 282
 283 static int srp_it_nexus_response(struct Scsi_Host *shost, u64 id, int result)
 284 {
 285         struct srp_internal *i = to_srp_internal(shost->transportt);
 286         return i->f->it_nexus_response(shost, id, result);
 287 }
 288
 289 /**
 290  * srp_attach_transport  --  instantiate SRP transport template
 291  * @ft:         SRP transport class function template
 292  */
 293 struct scsi_transport_template *
 294 srp_attach_transport(struct srp_function_template *ft)
 295 {
 296         int count;
 297         struct srp_internal *i;
 298
 299         i = kzalloc(sizeof(*i), GFP_KERNEL);
 300         if (!i)
 301                 return NULL;
 302
 303         i->t.it_nexus_response = srp_it_nexus_response;
 304
 305         i->t.host_size = sizeof(struct srp_host_attrs);
 306         i->t.host_attrs.ac.attrs = &i->host_attrs[0];
 307         i->t.host_attrs.ac.class = &srp_host_class.class;
 308         i->t.host_attrs.ac.match = srp_host_match;
 309         i->host_attrs[0] = NULL;
 310         transport_container_register(&i->t.host_attrs);
 311
 312         i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
 313         i->rport_attr_cont.ac.class = &srp_rport_class.class;
 314         i->rport_attr_cont.ac.match = srp_rport_match;
 315         transport_container_register(&i->rport_attr_cont);
 316
 317         count = 0;
 318         SETUP_RPORT_ATTRIBUTE_RD(port_id);
 319         SETUP_RPORT_ATTRIBUTE_RD(roles);
 320         i->rport_attrs[count] = NULL;
 321
 322         i->f = ft;
 323
 324         return &i->t;
 325 }
 326 EXPORT_SYMBOL_GPL(srp_attach_transport);
 327
 328 /**
 329  * srp_release_transport  --  release SRP transport template instance
 330  * @t:          transport template instance
 331  */
 332 void srp_release_transport(struct scsi_transport_template *t)
 333 {
 334         struct srp_internal *i = to_srp_internal(t);
 335
 336         transport_container_unregister(&i->t.host_attrs);
 337         transport_container_unregister(&i->rport_attr_cont);
 338
 339         kfree(i);
 340 }
 341 EXPORT_SYMBOL_GPL(srp_release_transport);
 342
 343 static __init int srp_transport_init(void)
 344 {
 345         int ret;
 346
 347         ret = transport_class_register(&srp_host_class);
 348         if (ret)
 349                 return ret;
 350         ret = transport_class_register(&srp_rport_class);
 351         if (ret)
 352                 goto unregister_host_class;
 353
 354         return 0;
 355 unregister_host_class:
 356         transport_class_unregister(&srp_host_class);
 357         return ret;
 358 }
 359
 360 static void __exit srp_transport_exit(void)
 361 {
 362         transport_class_unregister(&srp_host_class);
 363         transport_class_unregister(&srp_rport_class);
 364 }
 365
 366 MODULE_AUTHOR("FUJITA Tomonori");
 367 MODULE_DESCRIPTION("SRP Transport Attributes");
 368 MODULE_LICENSE("GPL");
 369
 370 module_init(srp_transport_init);
 371 module_exit(srp_transport_exit);