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 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
  59 static 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
  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] = 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
 102 static ssize_t
 103 show_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
 110 static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
 111
 112 static 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
 120 static ssize_t
 121 show_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
 136 static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
 137
 138 static 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
 146 static int scsi_is_srp_rport(const struct device *dev)
 147 {
 148         return dev->release == srp_rport_release;
 149 }
 150
 151 static 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
 170 static 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  */
 195 struct 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 }
 243 EXPORT_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  */
 251 void 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 }
 265 EXPORT_SYMBOL_GPL(srp_rport_del);
 266
 267 static 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  */
 281 void srp_remove_host(struct Scsi_Host *shost)
 282 {
 283         device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
 284 }
 285 EXPORT_SYMBOL_GPL(srp_remove_host);
 286
 287 static 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
 294 static 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  */
 304 struct scsi_transport_template *
 305 srp_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 }
 338 EXPORT_SYMBOL_GPL(srp_attach_transport);
 339
 340 /**
 341  * srp_release_transport  -  release SRP transport template instance
 342  * @t:          transport template instance
 343  */
 344 void 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 }
 353 EXPORT_SYMBOL_GPL(srp_release_transport);
 354
 355 static __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;
 367 unregister_host_class:
 368         transport_class_unregister(&srp_host_class);
 369         return ret;
 370 }
 371
 372 static void __exit srp_transport_exit(void)
 373 {
 374         transport_class_unregister(&srp_host_class);
 375         transport_class_unregister(&srp_rport_class);
 376 }
 377
 378 MODULE_AUTHOR("FUJITA Tomonori");
 379 MODULE_DESCRIPTION("SRP Transport Attributes");
 380 MODULE_LICENSE("GPL");
 381
 382 module_init(srp_transport_init);
 383 module_exit(srp_transport_exit);