drivers/s390/cio/scm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Recognize and maintain s390 storage class memory.
   4  *
   5  * Copyright IBM Corp. 2012
   6  * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
   7  */
   8
   9 #include <linux/device.h>
  10 #include <linux/module.h>
  11 #include <linux/mutex.h>
  12 #include <linux/slab.h>
  13 #include <linux/init.h>
  14 #include <linux/err.h>
  15 #include <asm/eadm.h>
  16 #include "chsc.h"
  17
  18 static struct device *scm_root;
  19
  20 #define to_scm_dev(n) container_of(n, struct scm_device, dev)
  21 #define to_scm_drv(d) container_of(d, struct scm_driver, drv)
  22
  23 static int scmdev_probe(struct device *dev)
  24 {
  25         struct scm_device *scmdev = to_scm_dev(dev);
  26         struct scm_driver *scmdrv = to_scm_drv(dev->driver);
  27
  28         return scmdrv->probe ? scmdrv->probe(scmdev) : -ENODEV;
  29 }
  30
  31 static void scmdev_remove(struct device *dev)
  32 {
  33         struct scm_device *scmdev = to_scm_dev(dev);
  34         struct scm_driver *scmdrv = to_scm_drv(dev->driver);
  35
  36         if (scmdrv->remove)
  37                 scmdrv->remove(scmdev);
  38 }
  39
  40 static int scmdev_uevent(const struct device *dev, struct kobj_uevent_env *env)
  41 {
  42         return add_uevent_var(env, "MODALIAS=scm:scmdev");
  43 }
  44
  45 static struct bus_type scm_bus_type = {
  46         .name  = "scm",
  47         .probe = scmdev_probe,
  48         .remove = scmdev_remove,
  49         .uevent = scmdev_uevent,
  50 };
  51
  52 /**
  53  * scm_driver_register() - register a scm driver
  54  * @scmdrv: driver to be registered
  55  */
  56 int scm_driver_register(struct scm_driver *scmdrv)
  57 {
  58         struct device_driver *drv = &scmdrv->drv;
  59
  60         drv->bus = &scm_bus_type;
  61
  62         return driver_register(drv);
  63 }
  64 EXPORT_SYMBOL_GPL(scm_driver_register);
  65
  66 /**
  67  * scm_driver_unregister() - deregister a scm driver
  68  * @scmdrv: driver to be deregistered
  69  */
  70 void scm_driver_unregister(struct scm_driver *scmdrv)
  71 {
  72         driver_unregister(&scmdrv->drv);
  73 }
  74 EXPORT_SYMBOL_GPL(scm_driver_unregister);
  75
  76 void scm_irq_handler(struct aob *aob, blk_status_t error)
  77 {
  78         struct aob_rq_header *aobrq = (void *) aob->request.data;
  79         struct scm_device *scmdev = aobrq->scmdev;
  80         struct scm_driver *scmdrv = to_scm_drv(scmdev->dev.driver);
  81
  82         scmdrv->handler(scmdev, aobrq->data, error);
  83 }
  84 EXPORT_SYMBOL_GPL(scm_irq_handler);
  85
  86 #define scm_attr(name)                                                  \
  87 static ssize_t show_##name(struct device *dev,                          \
  88                struct device_attribute *attr, char *buf)                \
  89 {                                                                       \
  90         struct scm_device *scmdev = to_scm_dev(dev);                    \
  91         int ret;                                                        \
  92                                                                         \
  93         device_lock(dev);                                               \
  94         ret = sprintf(buf, "%u\n", scmdev->attrs.name);                 \
  95         device_unlock(dev);                                             \
  96                                                                         \
  97         return ret;                                                     \
  98 }                                                                       \
  99 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
 100
 101 scm_attr(persistence);
 102 scm_attr(oper_state);
 103 scm_attr(data_state);
 104 scm_attr(rank);
 105 scm_attr(release);
 106 scm_attr(res_id);
 107
 108 static struct attribute *scmdev_attrs[] = {
 109         &dev_attr_persistence.attr,
 110         &dev_attr_oper_state.attr,
 111         &dev_attr_data_state.attr,
 112         &dev_attr_rank.attr,
 113         &dev_attr_release.attr,
 114         &dev_attr_res_id.attr,
 115         NULL,
 116 };
 117
 118 static struct attribute_group scmdev_attr_group = {
 119         .attrs = scmdev_attrs,
 120 };
 121
 122 static const struct attribute_group *scmdev_attr_groups[] = {
 123         &scmdev_attr_group,
 124         NULL,
 125 };
 126
 127 static void scmdev_release(struct device *dev)
 128 {
 129         struct scm_device *scmdev = to_scm_dev(dev);
 130
 131         kfree(scmdev);
 132 }
 133
 134 static void scmdev_setup(struct scm_device *scmdev, struct sale *sale,
 135                          unsigned int size, unsigned int max_blk_count)
 136 {
 137         dev_set_name(&scmdev->dev, "%016llx", (unsigned long long) sale->sa);
 138         scmdev->nr_max_block = max_blk_count;
 139         scmdev->address = sale->sa;
 140         scmdev->size = 1UL << size;
 141         scmdev->attrs.rank = sale->rank;
 142         scmdev->attrs.persistence = sale->p;
 143         scmdev->attrs.oper_state = sale->op_state;
 144         scmdev->attrs.data_state = sale->data_state;
 145         scmdev->attrs.rank = sale->rank;
 146         scmdev->attrs.release = sale->r;
 147         scmdev->attrs.res_id = sale->rid;
 148         scmdev->dev.parent = scm_root;
 149         scmdev->dev.bus = &scm_bus_type;
 150         scmdev->dev.release = scmdev_release;
 151         scmdev->dev.groups = scmdev_attr_groups;
 152 }
 153
 154 /*
 155  * Check for state-changes, notify the driver and userspace.
 156  */
 157 static void scmdev_update(struct scm_device *scmdev, struct sale *sale)
 158 {
 159         struct scm_driver *scmdrv;
 160         bool changed;
 161
 162         device_lock(&scmdev->dev);
 163         changed = scmdev->attrs.rank != sale->rank ||
 164                   scmdev->attrs.oper_state != sale->op_state;
 165         scmdev->attrs.rank = sale->rank;
 166         scmdev->attrs.oper_state = sale->op_state;
 167         if (!scmdev->dev.driver)
 168                 goto out;
 169         scmdrv = to_scm_drv(scmdev->dev.driver);
 170         if (changed && scmdrv->notify)
 171                 scmdrv->notify(scmdev, SCM_CHANGE);
 172 out:
 173         device_unlock(&scmdev->dev);
 174         if (changed)
 175                 kobject_uevent(&scmdev->dev.kobj, KOBJ_CHANGE);
 176 }
 177
 178 static int check_address(struct device *dev, const void *data)
 179 {
 180         struct scm_device *scmdev = to_scm_dev(dev);
 181         const struct sale *sale = data;
 182
 183         return scmdev->address == sale->sa;
 184 }
 185
 186 static struct scm_device *scmdev_find(struct sale *sale)
 187 {
 188         struct device *dev;
 189
 190         dev = bus_find_device(&scm_bus_type, NULL, sale, check_address);
 191
 192         return dev ? to_scm_dev(dev) : NULL;
 193 }
 194
 195 static int scm_add(struct chsc_scm_info *scm_info, size_t num)
 196 {
 197         struct sale *sale, *scmal = scm_info->scmal;
 198         struct scm_device *scmdev;
 199         int ret;
 200
 201         for (sale = scmal; sale < scmal + num; sale++) {
 202                 scmdev = scmdev_find(sale);
 203                 if (scmdev) {
 204                         scmdev_update(scmdev, sale);
 205                         /* Release reference from scm_find(). */
 206                         put_device(&scmdev->dev);
 207                         continue;
 208                 }
 209                 scmdev = kzalloc(sizeof(*scmdev), GFP_KERNEL);
 210                 if (!scmdev)
 211                         return -ENODEV;
 212                 scmdev_setup(scmdev, sale, scm_info->is, scm_info->mbc);
 213                 ret = device_register(&scmdev->dev);
 214                 if (ret) {
 215                         /* Release reference from device_initialize(). */
 216                         put_device(&scmdev->dev);
 217                         return ret;
 218                 }
 219         }
 220
 221         return 0;
 222 }
 223
 224 int scm_update_information(void)
 225 {
 226         struct chsc_scm_info *scm_info;
 227         u64 token = 0;
 228         size_t num;
 229         int ret;
 230
 231         scm_info = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
 232         if (!scm_info)
 233                 return -ENOMEM;
 234
 235         do {
 236                 ret = chsc_scm_info(scm_info, token);
 237                 if (ret)
 238                         break;
 239
 240                 num = (scm_info->response.length -
 241                        (offsetof(struct chsc_scm_info, scmal) -
 242                         offsetof(struct chsc_scm_info, response))
 243                       ) / sizeof(struct sale);
 244
 245                 ret = scm_add(scm_info, num);
 246                 if (ret)
 247                         break;
 248
 249                 token = scm_info->restok;
 250         } while (token);
 251
 252         free_page((unsigned long)scm_info);
 253
 254         return ret;
 255 }
 256
 257 static int scm_dev_avail(struct device *dev, void *unused)
 258 {
 259         struct scm_driver *scmdrv = to_scm_drv(dev->driver);
 260         struct scm_device *scmdev = to_scm_dev(dev);
 261
 262         if (dev->driver && scmdrv->notify)
 263                 scmdrv->notify(scmdev, SCM_AVAIL);
 264
 265         return 0;
 266 }
 267
 268 int scm_process_availability_information(void)
 269 {
 270         return bus_for_each_dev(&scm_bus_type, NULL, NULL, scm_dev_avail);
 271 }
 272
 273 static int __init scm_init(void)
 274 {
 275         int ret;
 276
 277         ret = bus_register(&scm_bus_type);
 278         if (ret)
 279                 return ret;
 280
 281         scm_root = root_device_register("scm");
 282         if (IS_ERR(scm_root)) {
 283                 bus_unregister(&scm_bus_type);
 284                 return PTR_ERR(scm_root);
 285         }
 286
 287         scm_update_information();
 288         return 0;
 289 }
 290 subsys_initcall_sync(scm_init);