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
  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 3
  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 void srp_rport_release(struct device *dev)
 111 {
 112         struct srp_rport *rport = dev_to_rport(dev);
 113
 114         put_device(dev->parent);
 115         kfree(rport);
 116 }
 117
 118 static int scsi_is_srp_rport(const struct device *dev)
 119 {
 120         return dev->release == srp_rport_release;
 121 }
 122
 123 static int srp_rport_match(struct attribute_container *cont,
 124                            struct device *dev)
 125 {
 126         struct Scsi_Host *shost;
 127         struct srp_internal *i;
 128
 129         if (!scsi_is_srp_rport(dev))
 130                 return 0;
 131
 132         shost = dev_to_shost(dev->parent);
 133         if (!shost->transportt)
 134                 return 0;
 135         if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
 136                 return 0;
 137
 138         i = to_srp_internal(shost->transportt);
 139         return &i->rport_attr_cont.ac == cont;
 140 }
 141
 142 static int srp_host_match(struct attribute_container *cont, struct device *dev)
 143 {
 144         struct Scsi_Host *shost;
 145         struct srp_internal *i;
 146
 147         if (!scsi_is_host_device(dev))
 148                 return 0;
 149
 150         shost = dev_to_shost(dev);
 151         if (!shost->transportt)
 152                 return 0;
 153         if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
 154                 return 0;
 155
 156         i = to_srp_internal(shost->transportt);
 157         return &i->t.host_attrs.ac == cont;
 158 }
 159
 160 /**
 161  * srp_rport_add - add a SRP remote port to the device hierarchy
 162  *
 163  * @shost:      scsi host the remote port is connected to.
 164  * @ids:        The port id for the remote port.
 165  *
 166  * publishes a port to the rest of the system
 167  */
 168 struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
 169                                 struct srp_rport_identifiers *ids)
 170 {
 171         struct srp_rport *rport;
 172         struct device *parent = &shost->shost_gendev;
 173         int id, ret;
 174
 175         rport = kzalloc(sizeof(*rport), GFP_KERNEL);
 176         if (!rport)
 177                 return ERR_PTR(-ENOMEM);
 178
 179         device_initialize(&rport->dev);
 180
 181         rport->dev.parent = get_device(parent);
 182         rport->dev.release = srp_rport_release;
 183
 184         memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
 185
 186         id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
 187         sprintf(rport->dev.bus_id, "port-%d:%d", shost->host_no, id);
 188
 189         transport_setup_device(&rport->dev);
 190
 191         ret = device_add(&rport->dev);
 192         if (ret) {
 193                 transport_destroy_device(&rport->dev);
 194                 put_device(&rport->dev);
 195                 return ERR_PTR(ret);
 196         }
 197
 198         transport_add_device(&rport->dev);
 199         transport_configure_device(&rport->dev);
 200
 201         return rport;
 202 }
 203 EXPORT_SYMBOL_GPL(srp_rport_add);
 204
 205 /**
 206  * srp_rport_del  --  remove a SRP remote port
 207  * @port:       SRP remote port to remove
 208  *
 209  * Removes the specified SRP remote port.
 210  */
 211 void srp_rport_del(struct srp_rport *rport)
 212 {
 213         struct device *dev = &rport->dev;
 214
 215         transport_remove_device(dev);
 216         device_del(dev);
 217         transport_destroy_device(dev);
 218         put_device(dev);
 219 }
 220 EXPORT_SYMBOL_GPL(srp_rport_del);
 221
 222 static int do_srp_rport_del(struct device *dev, void *data)
 223 {
 224         srp_rport_del(dev_to_rport(dev));
 225         return 0;
 226 }
 227
 228 /**
 229  * srp_remove_host  --  tear down a Scsi_Host's SRP data structures
 230  * @shost:      Scsi Host that is torn down
 231  *
 232  * Removes all SRP remote ports for a given Scsi_Host.
 233  * Must be called just before scsi_remove_host for SRP HBAs.
 234  */
 235 void srp_remove_host(struct Scsi_Host *shost)
 236 {
 237         device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
 238 }
 239 EXPORT_SYMBOL_GPL(srp_remove_host);
 240
 241 /**
 242  * srp_attach_transport  --  instantiate SRP transport template
 243  * @ft:         SRP transport class function template
 244  */
 245 struct scsi_transport_template *
 246 srp_attach_transport(struct srp_function_template *ft)
 247 {
 248         int count;
 249         struct srp_internal *i;
 250
 251         i = kzalloc(sizeof(*i), GFP_KERNEL);
 252         if (!i)
 253                 return NULL;
 254
 255         i->t.host_size = sizeof(struct srp_host_attrs);
 256         i->t.host_attrs.ac.attrs = &i->host_attrs[0];
 257         i->t.host_attrs.ac.class = &srp_host_class.class;
 258         i->t.host_attrs.ac.match = srp_host_match;
 259         i->host_attrs[0] = NULL;
 260         transport_container_register(&i->t.host_attrs);
 261
 262         i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
 263         i->rport_attr_cont.ac.class = &srp_rport_class.class;
 264         i->rport_attr_cont.ac.match = srp_rport_match;
 265         transport_container_register(&i->rport_attr_cont);
 266
 267         count = 0;
 268         SETUP_RPORT_ATTRIBUTE_RD(port_id);
 269         i->rport_attrs[count] = NULL;
 270
 271         i->f = ft;
 272
 273         return &i->t;
 274 }
 275 EXPORT_SYMBOL_GPL(srp_attach_transport);
 276
 277 /**
 278  * srp_release_transport  --  release SRP transport template instance
 279  * @t:          transport template instance
 280  */
 281 void srp_release_transport(struct scsi_transport_template *t)
 282 {
 283         struct srp_internal *i = to_srp_internal(t);
 284
 285         transport_container_unregister(&i->t.host_attrs);
 286         transport_container_unregister(&i->rport_attr_cont);
 287
 288         kfree(i);
 289 }
 290 EXPORT_SYMBOL_GPL(srp_release_transport);
 291
 292 static __init int srp_transport_init(void)
 293 {
 294         int ret;
 295
 296         ret = transport_class_register(&srp_host_class);
 297         if (ret)
 298                 return ret;
 299         ret = transport_class_register(&srp_rport_class);
 300         if (ret)
 301                 goto unregister_host_class;
 302
 303         return 0;
 304 unregister_host_class:
 305         transport_class_unregister(&srp_host_class);
 306         return ret;
 307 }
 308
 309 static void __exit srp_transport_exit(void)
 310 {
 311         transport_class_unregister(&srp_host_class);
 312         transport_class_unregister(&srp_rport_class);
 313 }
 314
 315 MODULE_AUTHOR("FUJITA Tomonori");
 316 MODULE_DESCRIPTION("SRP Transport Attributes");
 317 MODULE_LICENSE("GPL");
 318
 319 module_init(srp_transport_init);
 320 module_exit(srp_transport_exit);