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