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 3
  42
  43 struct 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 transport_container rport_attr_cont;
  51 };
  52
  53 #define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
  54
  55 #define dev_to_rport(d) container_of(d, struct srp_rport, dev)
  56 #define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
  57
  58 static int srp_host_setup(struct transport_container *tc, struct device *dev,
  59                           struct device *cdev)
  60 {
  61         struct Scsi_Host *shost = dev_to_shost(dev);
  62         struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
  63
  64         atomic_set(&srp_host->next_port_id, 0);
  65         return 0;
  66 }
  67
  68 static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
  69                                NULL, NULL);
  70
  71 static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
  72                                NULL, NULL, NULL);
  73
  74 #define SRP_PID(p) \
  75         (p)->port_id[0], (p)->port_id[1], (p)->port_id[2], (p)->port_id[3], \
  76         (p)->port_id[4], (p)->port_id[5], (p)->port_id[6], (p)->port_id[7], \
  77         (p)->port_id[8], (p)->port_id[9], (p)->port_id[10], (p)->port_id[11], \
  78         (p)->port_id[12], (p)->port_id[13], (p)->port_id[14], (p)->port_id[15]
  79
  80 #define SRP_PID_FMT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:" \
  81         "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"
  82
  83 static ssize_t
  84 show_srp_rport_id(struct device *dev, struct device_attribute *attr,
  85                   char *buf)
  86 {
  87         struct srp_rport *rport = transport_class_to_srp_rport(dev);
  88         return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport));
  89 }
  90
  91 static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
  92
  93 static const struct {
  94         u32 value;
  95         char *name;
  96 } srp_rport_role_names[] = {
  97         {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
  98         {SRP_RPORT_ROLE_TARGET, "SRP Target"},
  99 };
 100
 101 static ssize_t
 102 show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
 103                      char *buf)
 104 {
 105         struct srp_rport *rport = transport_class_to_srp_rport(dev);
 106         int i;
 107         char *name = NULL;
 108
 109         for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
 110                 if (srp_rport_role_names[i].value == rport->roles) {
 111                         name = srp_rport_role_names[i].name;
 112                         break;
 113                 }
 114         return sprintf(buf, "%s\n", name ? : "unknown");
 115 }
 116
 117 static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
 118
 119 static ssize_t store_srp_rport_delete(struct device *dev,
 120                                       struct device_attribute *attr,
 121                                       const char *buf, size_t count)
 122 {
 123         struct srp_rport *rport = transport_class_to_srp_rport(dev);
 124         struct Scsi_Host *shost = dev_to_shost(dev);
 125         struct srp_internal *i = to_srp_internal(shost->transportt);
 126
 127         if (i->f->rport_delete) {
 128                 i->f->rport_delete(rport);
 129                 return count;
 130         } else {
 131                 return -ENOSYS;
 132         }
 133 }
 134
 135 static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete);
 136
 137 static void srp_rport_release(struct device *dev)
 138 {
 139         struct srp_rport *rport = dev_to_rport(dev);
 140
 141         put_device(dev->parent);
 142         kfree(rport);
 143 }
 144
 145 static int scsi_is_srp_rport(const struct device *dev)
 146 {
 147         return dev->release == srp_rport_release;
 148 }
 149
 150 static int srp_rport_match(struct attribute_container *cont,
 151                            struct device *dev)
 152 {
 153         struct Scsi_Host *shost;
 154         struct srp_internal *i;
 155
 156         if (!scsi_is_srp_rport(dev))
 157                 return 0;
 158
 159         shost = dev_to_shost(dev->parent);
 160         if (!shost->transportt)
 161                 return 0;
 162         if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
 163                 return 0;
 164
 165         i = to_srp_internal(shost->transportt);
 166         return &i->rport_attr_cont.ac == cont;
 167 }
 168
 169 static int srp_host_match(struct attribute_container *cont, struct device *dev)
 170 {
 171         struct Scsi_Host *shost;
 172         struct srp_internal *i;
 173
 174         if (!scsi_is_host_device(dev))
 175                 return 0;
 176
 177         shost = dev_to_shost(dev);
 178         if (!shost->transportt)
 179                 return 0;
 180         if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
 181                 return 0;
 182
 183         i = to_srp_internal(shost->transportt);
 184         return &i->t.host_attrs.ac == cont;
 185 }
 186
 187 /**
 188  * srp_rport_add - add a SRP remote port to the device hierarchy
 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         dev_set_name(&rport->dev, "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  * @rport:      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
 327         count = 0;
 328         i->rport_attrs[count++] = &dev_attr_port_id;
 329         i->rport_attrs[count++] = &dev_attr_roles;
 330         if (ft->rport_delete)
 331                 i->rport_attrs[count++] = &dev_attr_delete;
 332         i->rport_attrs[count++] = NULL;
 333         BUG_ON(count > ARRAY_SIZE(i->rport_attrs));
 334
 335         transport_container_register(&i->rport_attr_cont);
 336
 337         i->f = ft;
 338
 339         return &i->t;
 340 }
 341 EXPORT_SYMBOL_GPL(srp_attach_transport);
 342
 343 /**
 344  * srp_release_transport  -  release SRP transport template instance
 345  * @t:          transport template instance
 346  */
 347 void srp_release_transport(struct scsi_transport_template *t)
 348 {
 349         struct srp_internal *i = to_srp_internal(t);
 350
 351         transport_container_unregister(&i->t.host_attrs);
 352         transport_container_unregister(&i->rport_attr_cont);
 353
 354         kfree(i);
 355 }
 356 EXPORT_SYMBOL_GPL(srp_release_transport);
 357
 358 static __init int srp_transport_init(void)
 359 {
 360         int ret;
 361
 362         ret = transport_class_register(&srp_host_class);
 363         if (ret)
 364                 return ret;
 365         ret = transport_class_register(&srp_rport_class);
 366         if (ret)
 367                 goto unregister_host_class;
 368
 369         return 0;
 370 unregister_host_class:
 371         transport_class_unregister(&srp_host_class);
 372         return ret;
 373 }
 374
 375 static void __exit srp_transport_exit(void)
 376 {
 377         transport_class_unregister(&srp_host_class);
 378         transport_class_unregister(&srp_rport_class);
 379 }
 380
 381 MODULE_AUTHOR("FUJITA Tomonori");
 382 MODULE_DESCRIPTION("SRP Transport Attributes");
 383 MODULE_LICENSE("GPL");
 384
 385 module_init(srp_transport_init);
 386 module_exit(srp_transport_exit);