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(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); 291