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1// SPDX-License-Identifier: GPL-2.02/*3 * Recognize and maintain s390 storage class memory.4 *5 * Copyright IBM Corp. 20126 * 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 18static 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 23static 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 31static 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 40static int scmdev_uevent(const struct device *dev, struct kobj_uevent_env *env)41{42 return add_uevent_var(env, "MODALIAS=scm:scmdev");43}44 45static const 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 driver54 * @scmdrv: driver to be registered55 */56int 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}64EXPORT_SYMBOL_GPL(scm_driver_register);65 66/**67 * scm_driver_unregister() - deregister a scm driver68 * @scmdrv: driver to be deregistered69 */70void scm_driver_unregister(struct scm_driver *scmdrv)71{72 driver_unregister(&scmdrv->drv);73}74EXPORT_SYMBOL_GPL(scm_driver_unregister);75 76void 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}84EXPORT_SYMBOL_GPL(scm_irq_handler);85 86#define scm_attr(name) \87static 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} \99static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);100 101scm_attr(persistence);102scm_attr(oper_state);103scm_attr(data_state);104scm_attr(rank);105scm_attr(release);106scm_attr(res_id);107 108static 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 118static struct attribute_group scmdev_attr_group = {119 .attrs = scmdev_attrs,120};121 122static const struct attribute_group *scmdev_attr_groups[] = {123 &scmdev_attr_group,124 NULL,125};126 127static void scmdev_release(struct device *dev)128{129 struct scm_device *scmdev = to_scm_dev(dev);130 131 kfree(scmdev);132}133 134static 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 */157static 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);172out:173 device_unlock(&scmdev->dev);174 if (changed)175 kobject_uevent(&scmdev->dev.kobj, KOBJ_CHANGE);176}177 178static 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 186static 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 195static 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 224int 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);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 257static 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 268int scm_process_availability_information(void)269{270 return bus_for_each_dev(&scm_bus_type, NULL, NULL, scm_dev_avail);271}272 273static 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}290subsys_initcall_sync(scm_init);291