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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
  34 struct srp_host_attrs {
  35         atomic_t next_port_id;
  36 };
  37 #define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
  38
  39 #define SRP_HOST_ATTRS 0
  40 #define SRP_RPORT_ATTRS 2
  41
  42 struct srp_internal {
  43         struct scsi_transport_template t;
  44         struct srp_function_template *f;
  45
  46         struct class_device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
  47
  48         struct class_device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
  49         struct class_device_attribute private_rport_attrs[SRP_RPORT_ATTRS];
  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(cdev) dev_to_rport((cdev)->dev)
  57
  58 static int srp_host_setup(struct transport_container *tc, struct device *dev,
  59                           struct class_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 SETUP_TEMPLATE(attrb, field, perm, test, ro_test, ro_perm)      \
  75         i->private_##attrb[count] = class_device_attr_##field;          \
  76         i->private_##attrb[count].attr.mode = perm;                     \
  77         if (ro_test) {                                                  \
  78                 i->private_##attrb[count].attr.mode = ro_perm;          \
  79                 i->private_##attrb[count].store = NULL;                 \
  80         }                                                               \
  81         i->attrb[count] = &i->private_##attrb[count];                   \
  82         if (test)                                                       \
  83                 count++
  84
  85 #define SETUP_RPORT_ATTRIBUTE_RD(field)                                 \
  86         SETUP_TEMPLATE(rport_attrs, field, S_IRUGO, 1, 0, 0)
  87
  88 #define SETUP_RPORT_ATTRIBUTE_RW(field)                                 \
  89         SETUP_TEMPLATE(rport_attrs, field, S_IRUGO | S_IWUSR,           \
  90                        1, 1, S_IRUGO)
  91
  92 #define SRP_PID(p) \
  93         (p)->port_id[0], (p)->port_id[1], (p)->port_id[2], (p)->port_id[3], \
  94         (p)->port_id[4], (p)->port_id[5], (p)->port_id[6], (p)->port_id[7], \
  95         (p)->port_id[8], (p)->port_id[9], (p)->port_id[10], (p)->port_id[11], \
  96         (p)->port_id[12], (p)->port_id[13], (p)->port_id[14], (p)->port_id[15]
  97
  98 #define SRP_PID_FMT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:" \
  99         "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"
 100
 101 static ssize_t
 102 show_srp_rport_id(struct class_device *cdev, char *buf)
 103 {
 104         struct srp_rport *rport = transport_class_to_srp_rport(cdev);
 105         return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport));
 106 }
 107
 108 static CLASS_DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
 109
 110 static const struct {
 111         u32 value;
 112         char *name;
 113 } srp_rport_role_names[] = {
 114         {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
 115         {SRP_RPORT_ROLE_TARGET, "SRP Target"},
 116 };
 117
 118 static ssize_t
 119 show_srp_rport_roles(struct class_device *cdev, char *buf)
 120 {
 121         struct srp_rport *rport = transport_class_to_srp_rport(cdev);
 122         int i;
 123         char *name = NULL;
 124
 125         for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
 126                 if (srp_rport_role_names[i].value == rport->roles) {
 127                         name = srp_rport_role_names[i].name;
 128                         break;
 129                 }
 130         return sprintf(buf, "%s\n", name ? : "unknown");
 131 }
 132
 133 static CLASS_DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
 134
 135 static void srp_rport_release(struct device *dev)
 136 {
 137         struct srp_rport *rport = dev_to_rport(dev);
 138
 139         put_device(dev->parent);
 140         kfree(rport);
 141 }
 142
 143 static int scsi_is_srp_rport(const struct device *dev)
 144 {
 145         return dev->release == srp_rport_release;
 146 }
 147
 148 static int srp_rport_match(struct attribute_container *cont,
 149                            struct device *dev)
 150 {
 151         struct Scsi_Host *shost;
 152         struct srp_internal *i;
 153
 154         if (!scsi_is_srp_rport(dev))
 155                 return 0;
 156
 157         shost = dev_to_shost(dev->parent);
 158         if (!shost->transportt)
 159                 return 0;
 160         if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
 161                 return 0;
 162
 163         i = to_srp_internal(shost->transportt);
 164         return &i->rport_attr_cont.ac == cont;
 165 }
 166
 167 static int srp_host_match(struct attribute_container *cont, struct device *dev)
 168 {
 169         struct Scsi_Host *shost;
 170         struct srp_internal *i;
 171
 172         if (!scsi_is_host_device(dev))
 173                 return 0;
 174
 175         shost = dev_to_shost(dev);
 176         if (!shost->transportt)
 177                 return 0;
 178         if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
 179                 return 0;
 180
 181         i = to_srp_internal(shost->transportt);
 182         return &i->t.host_attrs.ac == cont;
 183 }
 184
 185 /**
 186  * srp_rport_add - add a SRP remote port to the device hierarchy
 187  *
 188  * @shost:      scsi host the remote port is connected to.
 189  * @ids:        The port id for the remote port.
 190  *
 191  * publishes a port to the rest of the system
 192  */
 193 struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
 194                                 struct srp_rport_identifiers *ids)
 195 {
 196         struct srp_rport *rport;
 197         struct device *parent = &shost->shost_gendev;
 198         int id, ret;
 199
 200         rport = kzalloc(sizeof(*rport), GFP_KERNEL);
 201         if (!rport)
 202                 return ERR_PTR(-ENOMEM);
 203
 204         device_initialize(&rport->dev);
 205
 206         rport->dev.parent = get_device(parent);
 207         rport->dev.release = srp_rport_release;
 208
 209         memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
 210         rport->roles = ids->roles;
 211
 212         id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
 213         sprintf(rport->dev.bus_id, "port-%d:%d", shost->host_no, id);
 214
 215         transport_setup_device(&rport->dev);
 216
 217         ret = device_add(&rport->dev);
 218         if (ret) {
 219                 transport_destroy_device(&rport->dev);
 220                 put_device(&rport->dev);
 221                 return ERR_PTR(ret);
 222         }
 223
 224         transport_add_device(&rport->dev);
 225         transport_configure_device(&rport->dev);
 226
 227         return rport;
 228 }
 229 EXPORT_SYMBOL_GPL(srp_rport_add);
 230
 231 /**
 232  * srp_rport_del  --  remove a SRP remote port
 233  * @port:       SRP remote port to remove
 234  *
 235  * Removes the specified SRP remote port.
 236  */
 237 void srp_rport_del(struct srp_rport *rport)
 238 {
 239         struct device *dev = &rport->dev;
 240
 241         transport_remove_device(dev);
 242         device_del(dev);
 243         transport_destroy_device(dev);
 244         put_device(dev);
 245 }
 246 EXPORT_SYMBOL_GPL(srp_rport_del);
 247
 248 static int do_srp_rport_del(struct device *dev, void *data)
 249 {
 250         srp_rport_del(dev_to_rport(dev));
 251         return 0;
 252 }
 253
 254 /**
 255  * srp_remove_host  --  tear down a Scsi_Host's SRP data structures
 256  * @shost:      Scsi Host that is torn down
 257  *
 258  * Removes all SRP remote ports for a given Scsi_Host.
 259  * Must be called just before scsi_remove_host for SRP HBAs.
 260  */
 261 void srp_remove_host(struct Scsi_Host *shost)
 262 {
 263         device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
 264 }
 265 EXPORT_SYMBOL_GPL(srp_remove_host);
 266
 267 /**
 268  * srp_attach_transport  --  instantiate SRP transport template
 269  * @ft:         SRP transport class function template
 270  */
 271 struct scsi_transport_template *
 272 srp_attach_transport(struct srp_function_template *ft)
 273 {
 274         int count;
 275         struct srp_internal *i;
 276
 277         i = kzalloc(sizeof(*i), GFP_KERNEL);
 278         if (!i)
 279                 return NULL;
 280
 281         i->t.host_size = sizeof(struct srp_host_attrs);
 282         i->t.host_attrs.ac.attrs = &i->host_attrs[0];
 283         i->t.host_attrs.ac.class = &srp_host_class.class;
 284         i->t.host_attrs.ac.match = srp_host_match;
 285         i->host_attrs[0] = NULL;
 286         transport_container_register(&i->t.host_attrs);
 287
 288         i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
 289         i->rport_attr_cont.ac.class = &srp_rport_class.class;
 290         i->rport_attr_cont.ac.match = srp_rport_match;
 291         transport_container_register(&i->rport_attr_cont);
 292
 293         count = 0;
 294         SETUP_RPORT_ATTRIBUTE_RD(port_id);
 295         SETUP_RPORT_ATTRIBUTE_RD(roles);
 296         i->rport_attrs[count] = NULL;
 297
 298         i->f = ft;
 299
 300         return &i->t;
 301 }
 302 EXPORT_SYMBOL_GPL(srp_attach_transport);
 303
 304 /**
 305  * srp_release_transport  --  release SRP transport template instance
 306  * @t:          transport template instance
 307  */
 308 void srp_release_transport(struct scsi_transport_template *t)
 309 {
 310         struct srp_internal *i = to_srp_internal(t);
 311
 312         transport_container_unregister(&i->t.host_attrs);
 313         transport_container_unregister(&i->rport_attr_cont);
 314
 315         kfree(i);
 316 }
 317 EXPORT_SYMBOL_GPL(srp_release_transport);
 318
 319 static __init int srp_transport_init(void)
 320 {
 321         int ret;
 322
 323         ret = transport_class_register(&srp_host_class);
 324         if (ret)
 325                 return ret;
 326         ret = transport_class_register(&srp_rport_class);
 327         if (ret)
 328                 goto unregister_host_class;
 329
 330         return 0;
 331 unregister_host_class:
 332         transport_class_unregister(&srp_host_class);
 333         return ret;
 334 }
 335
 336 static void __exit srp_transport_exit(void)
 337 {
 338         transport_class_unregister(&srp_host_class);
 339         transport_class_unregister(&srp_rport_class);
 340 }
 341
 342 MODULE_AUTHOR("FUJITA Tomonori");
 343 MODULE_DESCRIPTION("SRP Transport Attributes");
 344 MODULE_LICENSE("GPL");
 345
 346 module_init(srp_transport_init);
 347 module_exit(srp_transport_exit);