drivers/net/netdevsim/bus.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2017 Netronome Systems, Inc.
   3  * Copyright (C) 2019 Mellanox Technologies. All rights reserved
   4  */
   5
   6 #include <linux/device.h>
   7 #include <linux/idr.h>
   8 #include <linux/kernel.h>
   9 #include <linux/list.h>
  10 #include <linux/mutex.h>
  11 #include <linux/rtnetlink.h>
  12 #include <linux/slab.h>
  13 #include <linux/sysfs.h>
  14
  15 #include "netdevsim.h"
  16
  17 static DEFINE_IDA(nsim_bus_dev_ids);
  18 static LIST_HEAD(nsim_bus_dev_list);
  19 static DEFINE_MUTEX(nsim_bus_dev_list_lock);
  20 static bool nsim_bus_enable;
  21
  22 static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
  23 {
  24         return container_of(dev, struct nsim_bus_dev, dev);
  25 }
  26
  27 static int nsim_bus_dev_vfs_enable(struct nsim_bus_dev *nsim_bus_dev,
  28                                    unsigned int num_vfs)
  29 {
  30         nsim_bus_dev->vfconfigs = kcalloc(num_vfs,
  31                                           sizeof(struct nsim_vf_config),
  32                                           GFP_KERNEL | __GFP_NOWARN);
  33         if (!nsim_bus_dev->vfconfigs)
  34                 return -ENOMEM;
  35         nsim_bus_dev->num_vfs = num_vfs;
  36
  37         return 0;
  38 }
  39
  40 static void nsim_bus_dev_vfs_disable(struct nsim_bus_dev *nsim_bus_dev)
  41 {
  42         kfree(nsim_bus_dev->vfconfigs);
  43         nsim_bus_dev->vfconfigs = NULL;
  44         nsim_bus_dev->num_vfs = 0;
  45 }
  46
  47 static ssize_t
  48 nsim_bus_dev_numvfs_store(struct device *dev, struct device_attribute *attr,
  49                           const char *buf, size_t count)
  50 {
  51         struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
  52         unsigned int num_vfs;
  53         int ret;
  54
  55         ret = kstrtouint(buf, 0, &num_vfs);
  56         if (ret)
  57                 return ret;
  58
  59         rtnl_lock();
  60         if (nsim_bus_dev->num_vfs == num_vfs)
  61                 goto exit_good;
  62         if (nsim_bus_dev->num_vfs && num_vfs) {
  63                 ret = -EBUSY;
  64                 goto exit_unlock;
  65         }
  66
  67         if (num_vfs) {
  68                 ret = nsim_bus_dev_vfs_enable(nsim_bus_dev, num_vfs);
  69                 if (ret)
  70                         goto exit_unlock;
  71         } else {
  72                 nsim_bus_dev_vfs_disable(nsim_bus_dev);
  73         }
  74 exit_good:
  75         ret = count;
  76 exit_unlock:
  77         rtnl_unlock();
  78
  79         return ret;
  80 }
  81
  82 static ssize_t
  83 nsim_bus_dev_numvfs_show(struct device *dev,
  84                          struct device_attribute *attr, char *buf)
  85 {
  86         struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
  87
  88         return sprintf(buf, "%u\n", nsim_bus_dev->num_vfs);
  89 }
  90
  91 static struct device_attribute nsim_bus_dev_numvfs_attr =
  92         __ATTR(sriov_numvfs, 0664, nsim_bus_dev_numvfs_show,
  93                nsim_bus_dev_numvfs_store);
  94
  95 static ssize_t
  96 new_port_store(struct device *dev, struct device_attribute *attr,
  97                const char *buf, size_t count)
  98 {
  99         struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 100         struct nsim_dev *nsim_dev = dev_get_drvdata(dev);
 101         struct devlink *devlink;
 102         unsigned int port_index;
 103         int ret;
 104
 105         /* Prevent to use nsim_bus_dev before initialization. */
 106         if (!smp_load_acquire(&nsim_bus_dev->init))
 107                 return -EBUSY;
 108         ret = kstrtouint(buf, 0, &port_index);
 109         if (ret)
 110                 return ret;
 111
 112         devlink = priv_to_devlink(nsim_dev);
 113
 114         mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
 115         devlink_reload_disable(devlink);
 116         ret = nsim_dev_port_add(nsim_bus_dev, port_index);
 117         devlink_reload_enable(devlink);
 118         mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
 119         return ret ? ret : count;
 120 }
 121
 122 static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);
 123
 124 static ssize_t
 125 del_port_store(struct device *dev, struct device_attribute *attr,
 126                const char *buf, size_t count)
 127 {
 128         struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 129         struct nsim_dev *nsim_dev = dev_get_drvdata(dev);
 130         struct devlink *devlink;
 131         unsigned int port_index;
 132         int ret;
 133
 134         /* Prevent to use nsim_bus_dev before initialization. */
 135         if (!smp_load_acquire(&nsim_bus_dev->init))
 136                 return -EBUSY;
 137         ret = kstrtouint(buf, 0, &port_index);
 138         if (ret)
 139                 return ret;
 140
 141         devlink = priv_to_devlink(nsim_dev);
 142
 143         mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
 144         devlink_reload_disable(devlink);
 145         ret = nsim_dev_port_del(nsim_bus_dev, port_index);
 146         devlink_reload_enable(devlink);
 147         mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
 148         return ret ? ret : count;
 149 }
 150
 151 static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);
 152
 153 static struct attribute *nsim_bus_dev_attrs[] = {
 154         &nsim_bus_dev_numvfs_attr.attr,
 155         &nsim_bus_dev_new_port_attr.attr,
 156         &nsim_bus_dev_del_port_attr.attr,
 157         NULL,
 158 };
 159
 160 static const struct attribute_group nsim_bus_dev_attr_group = {
 161         .attrs = nsim_bus_dev_attrs,
 162 };
 163
 164 static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
 165         &nsim_bus_dev_attr_group,
 166         NULL,
 167 };
 168
 169 static void nsim_bus_dev_release(struct device *dev)
 170 {
 171         struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 172
 173         nsim_bus_dev_vfs_disable(nsim_bus_dev);
 174 }
 175
 176 static struct device_type nsim_bus_dev_type = {
 177         .groups = nsim_bus_dev_attr_groups,
 178         .release = nsim_bus_dev_release,
 179 };
 180
 181 static struct nsim_bus_dev *
 182 nsim_bus_dev_new(unsigned int id, unsigned int port_count);
 183
 184 static ssize_t
 185 new_device_store(struct bus_type *bus, const char *buf, size_t count)
 186 {
 187         struct nsim_bus_dev *nsim_bus_dev;
 188         unsigned int port_count;
 189         unsigned int id;
 190         int err;
 191
 192         err = sscanf(buf, "%u %u", &id, &port_count);
 193         switch (err) {
 194         case 1:
 195                 port_count = 1;
 196                 /* fall through */
 197         case 2:
 198                 if (id > INT_MAX) {
 199                         pr_err("Value of \"id\" is too big.\n");
 200                         return -EINVAL;
 201                 }
 202                 break;
 203         default:
 204                 pr_err("Format for adding new device is \"id port_count\" (uint uint).\n");
 205                 return -EINVAL;
 206         }
 207
 208         mutex_lock(&nsim_bus_dev_list_lock);
 209         /* Prevent to use resource before initialization. */
 210         if (!smp_load_acquire(&nsim_bus_enable)) {
 211                 err = -EBUSY;
 212                 goto err;
 213         }
 214
 215         nsim_bus_dev = nsim_bus_dev_new(id, port_count);
 216         if (IS_ERR(nsim_bus_dev)) {
 217                 err = PTR_ERR(nsim_bus_dev);
 218                 goto err;
 219         }
 220
 221         /* Allow using nsim_bus_dev */
 222         smp_store_release(&nsim_bus_dev->init, true);
 223
 224         list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
 225         mutex_unlock(&nsim_bus_dev_list_lock);
 226
 227         return count;
 228 err:
 229         mutex_unlock(&nsim_bus_dev_list_lock);
 230         return err;
 231 }
 232 static BUS_ATTR_WO(new_device);
 233
 234 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
 235
 236 static ssize_t
 237 del_device_store(struct bus_type *bus, const char *buf, size_t count)
 238 {
 239         struct nsim_bus_dev *nsim_bus_dev, *tmp;
 240         unsigned int id;
 241         int err;
 242
 243         err = sscanf(buf, "%u", &id);
 244         switch (err) {
 245         case 1:
 246                 if (id > INT_MAX) {
 247                         pr_err("Value of \"id\" is too big.\n");
 248                         return -EINVAL;
 249                 }
 250                 break;
 251         default:
 252                 pr_err("Format for deleting device is \"id\" (uint).\n");
 253                 return -EINVAL;
 254         }
 255
 256         err = -ENOENT;
 257         mutex_lock(&nsim_bus_dev_list_lock);
 258         /* Prevent to use resource before initialization. */
 259         if (!smp_load_acquire(&nsim_bus_enable)) {
 260                 mutex_unlock(&nsim_bus_dev_list_lock);
 261                 return -EBUSY;
 262         }
 263         list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
 264                 if (nsim_bus_dev->dev.id != id)
 265                         continue;
 266                 list_del(&nsim_bus_dev->list);
 267                 nsim_bus_dev_del(nsim_bus_dev);
 268                 err = 0;
 269                 break;
 270         }
 271         mutex_unlock(&nsim_bus_dev_list_lock);
 272         return !err ? count : err;
 273 }
 274 static BUS_ATTR_WO(del_device);
 275
 276 static struct attribute *nsim_bus_attrs[] = {
 277         &bus_attr_new_device.attr,
 278         &bus_attr_del_device.attr,
 279         NULL
 280 };
 281 ATTRIBUTE_GROUPS(nsim_bus);
 282
 283 static int nsim_bus_probe(struct device *dev)
 284 {
 285         struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 286
 287         return nsim_dev_probe(nsim_bus_dev);
 288 }
 289
 290 static int nsim_bus_remove(struct device *dev)
 291 {
 292         struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 293
 294         nsim_dev_remove(nsim_bus_dev);
 295         return 0;
 296 }
 297
 298 static int nsim_num_vf(struct device *dev)
 299 {
 300         struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 301
 302         return nsim_bus_dev->num_vfs;
 303 }
 304
 305 static struct bus_type nsim_bus = {
 306         .name           = DRV_NAME,
 307         .dev_name       = DRV_NAME,
 308         .bus_groups     = nsim_bus_groups,
 309         .probe          = nsim_bus_probe,
 310         .remove         = nsim_bus_remove,
 311         .num_vf         = nsim_num_vf,
 312 };
 313
 314 static struct nsim_bus_dev *
 315 nsim_bus_dev_new(unsigned int id, unsigned int port_count)
 316 {
 317         struct nsim_bus_dev *nsim_bus_dev;
 318         int err;
 319
 320         nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
 321         if (!nsim_bus_dev)
 322                 return ERR_PTR(-ENOMEM);
 323
 324         err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
 325         if (err < 0)
 326                 goto err_nsim_bus_dev_free;
 327         nsim_bus_dev->dev.id = err;
 328         nsim_bus_dev->dev.bus = &nsim_bus;
 329         nsim_bus_dev->dev.type = &nsim_bus_dev_type;
 330         nsim_bus_dev->port_count = port_count;
 331         nsim_bus_dev->initial_net = current->nsproxy->net_ns;
 332         mutex_init(&nsim_bus_dev->nsim_bus_reload_lock);
 333         /* Disallow using nsim_bus_dev */
 334         smp_store_release(&nsim_bus_dev->init, false);
 335
 336         err = device_register(&nsim_bus_dev->dev);
 337         if (err)
 338                 goto err_nsim_bus_dev_id_free;
 339         return nsim_bus_dev;
 340
 341 err_nsim_bus_dev_id_free:
 342         ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
 343 err_nsim_bus_dev_free:
 344         kfree(nsim_bus_dev);
 345         return ERR_PTR(err);
 346 }
 347
 348 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
 349 {
 350         /* Disallow using nsim_bus_dev */
 351         smp_store_release(&nsim_bus_dev->init, false);
 352         device_unregister(&nsim_bus_dev->dev);
 353         ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
 354         kfree(nsim_bus_dev);
 355 }
 356
 357 static struct device_driver nsim_driver = {
 358         .name           = DRV_NAME,
 359         .bus            = &nsim_bus,
 360         .owner          = THIS_MODULE,
 361 };
 362
 363 int nsim_bus_init(void)
 364 {
 365         int err;
 366
 367         err = bus_register(&nsim_bus);
 368         if (err)
 369                 return err;
 370         err = driver_register(&nsim_driver);
 371         if (err)
 372                 goto err_bus_unregister;
 373         /* Allow using resources */
 374         smp_store_release(&nsim_bus_enable, true);
 375         return 0;
 376
 377 err_bus_unregister:
 378         bus_unregister(&nsim_bus);
 379         return err;
 380 }
 381
 382 void nsim_bus_exit(void)
 383 {
 384         struct nsim_bus_dev *nsim_bus_dev, *tmp;
 385
 386         /* Disallow using resources */
 387         smp_store_release(&nsim_bus_enable, false);
 388
 389         mutex_lock(&nsim_bus_dev_list_lock);
 390         list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
 391                 list_del(&nsim_bus_dev->list);
 392                 nsim_bus_dev_del(nsim_bus_dev);
 393         }
 394         mutex_unlock(&nsim_bus_dev_list_lock);
 395
 396         driver_unregister(&nsim_driver);
 397         bus_unregister(&nsim_bus);
 398 }