1 /* 2 * Driver for s390 eadm subchannels 3 * 4 * Copyright IBM Corp. 2012 5 * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com> 6 */ 7 8 #include <linux/kernel_stat.h> 9 #include <linux/completion.h> 10 #include <linux/workqueue.h> 11 #include <linux/spinlock.h> 12 #include <linux/device.h> 13 #include <linux/module.h> 14 #include <linux/timer.h> 15 #include <linux/slab.h> 16 #include <linux/list.h> 17 18 #include <asm/css_chars.h> 19 #include <asm/debug.h> 20 #include <asm/isc.h> 21 #include <asm/cio.h> 22 #include <asm/scsw.h> 23 #include <asm/eadm.h> 24 25 #include "eadm_sch.h" 26 #include "ioasm.h" 27 #include "cio.h" 28 #include "css.h" 29 #include "orb.h" 30 31 MODULE_DESCRIPTION("driver for s390 eadm subchannels"); 32 MODULE_LICENSE("GPL"); 33 34 #define EADM_TIMEOUT (5 * HZ) 35 static DEFINE_SPINLOCK(list_lock); 36 static LIST_HEAD(eadm_list); 37 38 static debug_info_t *eadm_debug; 39 40 #define EADM_LOG(imp, txt) do { \ 41 debug_text_event(eadm_debug, imp, txt); \ 42 } while (0) 43 44 static void EADM_LOG_HEX(int level, void *data, int length) 45 { 46 if (!debug_level_enabled(eadm_debug, level)) 47 return; 48 while (length > 0) { 49 debug_event(eadm_debug, level, data, length); 50 length -= eadm_debug->buf_size; 51 data += eadm_debug->buf_size; 52 } 53 } 54 55 static void orb_init(union orb *orb) 56 { 57 memset(orb, 0, sizeof(union orb)); 58 orb->eadm.compat1 = 1; 59 orb->eadm.compat2 = 1; 60 orb->eadm.fmt = 1; 61 orb->eadm.x = 1; 62 } 63 64 static int eadm_subchannel_start(struct subchannel *sch, struct aob *aob) 65 { 66 union orb *orb = &get_eadm_private(sch)->orb; 67 int cc; 68 69 orb_init(orb); 70 orb->eadm.aob = (u32)__pa(aob); 71 orb->eadm.intparm = (u32)(addr_t)sch; 72 orb->eadm.key = PAGE_DEFAULT_KEY >> 4; 73 74 EADM_LOG(6, "start"); 75 EADM_LOG_HEX(6, &sch->schid, sizeof(sch->schid)); 76 77 cc = ssch(sch->schid, orb); 78 switch (cc) { 79 case 0: 80 sch->schib.scsw.eadm.actl |= SCSW_ACTL_START_PEND; 81 break; 82 case 1: /* status pending */ 83 case 2: /* busy */ 84 return -EBUSY; 85 case 3: /* not operational */ 86 return -ENODEV; 87 } 88 return 0; 89 } 90 91 static int eadm_subchannel_clear(struct subchannel *sch) 92 { 93 int cc; 94 95 cc = csch(sch->schid); 96 if (cc) 97 return -ENODEV; 98 99 sch->schib.scsw.eadm.actl |= SCSW_ACTL_CLEAR_PEND; 100 return 0; 101 } 102 103 static void eadm_subchannel_timeout(unsigned long data) 104 { 105 struct subchannel *sch = (struct subchannel *) data; 106 107 spin_lock_irq(sch->lock); 108 EADM_LOG(1, "timeout"); 109 EADM_LOG_HEX(1, &sch->schid, sizeof(sch->schid)); 110 if (eadm_subchannel_clear(sch)) 111 EADM_LOG(0, "clear failed"); 112 spin_unlock_irq(sch->lock); 113 } 114 115 static void eadm_subchannel_set_timeout(struct subchannel *sch, int expires) 116 { 117 struct eadm_private *private = get_eadm_private(sch); 118 119 if (expires == 0) { 120 del_timer(&private->timer); 121 return; 122 } 123 if (timer_pending(&private->timer)) { 124 if (mod_timer(&private->timer, jiffies + expires)) 125 return; 126 } 127 private->timer.function = eadm_subchannel_timeout; 128 private->timer.data = (unsigned long) sch; 129 private->timer.expires = jiffies + expires; 130 add_timer(&private->timer); 131 } 132 133 static void eadm_subchannel_irq(struct subchannel *sch) 134 { 135 struct eadm_private *private = get_eadm_private(sch); 136 struct eadm_scsw *scsw = &sch->schib.scsw.eadm; 137 struct irb *irb = &__get_cpu_var(cio_irb); 138 int error = 0; 139 140 EADM_LOG(6, "irq"); 141 EADM_LOG_HEX(6, irb, sizeof(*irb)); 142 143 inc_irq_stat(IRQIO_ADM); 144 145 if ((scsw->stctl & (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) 146 && scsw->eswf == 1 && irb->esw.eadm.erw.r) 147 error = -EIO; 148 149 if (scsw->fctl & SCSW_FCTL_CLEAR_FUNC) 150 error = -ETIMEDOUT; 151 152 eadm_subchannel_set_timeout(sch, 0); 153 154 if (private->state != EADM_BUSY) { 155 EADM_LOG(1, "irq unsol"); 156 EADM_LOG_HEX(1, irb, sizeof(*irb)); 157 private->state = EADM_NOT_OPER; 158 css_sched_sch_todo(sch, SCH_TODO_EVAL); 159 return; 160 } 161 scm_irq_handler((struct aob *)(unsigned long)scsw->aob, error); 162 private->state = EADM_IDLE; 163 164 if (private->completion) 165 complete(private->completion); 166 } 167 168 static struct subchannel *eadm_get_idle_sch(void) 169 { 170 struct eadm_private *private; 171 struct subchannel *sch; 172 unsigned long flags; 173 174 spin_lock_irqsave(&list_lock, flags); 175 list_for_each_entry(private, &eadm_list, head) { 176 sch = private->sch; 177 spin_lock(sch->lock); 178 if (private->state == EADM_IDLE) { 179 private->state = EADM_BUSY; 180 list_move_tail(&private->head, &eadm_list); 181 spin_unlock(sch->lock); 182 spin_unlock_irqrestore(&list_lock, flags); 183 184 return sch; 185 } 186 spin_unlock(sch->lock); 187 } 188 spin_unlock_irqrestore(&list_lock, flags); 189 190 return NULL; 191 } 192 193 int eadm_start_aob(struct aob *aob) 194 { 195 struct eadm_private *private; 196 struct subchannel *sch; 197 unsigned long flags; 198 int ret; 199 200 sch = eadm_get_idle_sch(); 201 if (!sch) 202 return -EBUSY; 203 204 spin_lock_irqsave(sch->lock, flags); 205 eadm_subchannel_set_timeout(sch, EADM_TIMEOUT); 206 ret = eadm_subchannel_start(sch, aob); 207 if (!ret) 208 goto out_unlock; 209 210 /* Handle start subchannel failure. */ 211 eadm_subchannel_set_timeout(sch, 0); 212 private = get_eadm_private(sch); 213 private->state = EADM_NOT_OPER; 214 css_sched_sch_todo(sch, SCH_TODO_EVAL); 215 216 out_unlock: 217 spin_unlock_irqrestore(sch->lock, flags); 218 219 return ret; 220 } 221 EXPORT_SYMBOL_GPL(eadm_start_aob); 222 223 static int eadm_subchannel_probe(struct subchannel *sch) 224 { 225 struct eadm_private *private; 226 int ret; 227 228 private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); 229 if (!private) 230 return -ENOMEM; 231 232 INIT_LIST_HEAD(&private->head); 233 init_timer(&private->timer); 234 235 spin_lock_irq(sch->lock); 236 set_eadm_private(sch, private); 237 private->state = EADM_IDLE; 238 private->sch = sch; 239 sch->isc = EADM_SCH_ISC; 240 ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); 241 if (ret) { 242 set_eadm_private(sch, NULL); 243 spin_unlock_irq(sch->lock); 244 kfree(private); 245 goto out; 246 } 247 spin_unlock_irq(sch->lock); 248 249 spin_lock_irq(&list_lock); 250 list_add(&private->head, &eadm_list); 251 spin_unlock_irq(&list_lock); 252 253 if (dev_get_uevent_suppress(&sch->dev)) { 254 dev_set_uevent_suppress(&sch->dev, 0); 255 kobject_uevent(&sch->dev.kobj, KOBJ_ADD); 256 } 257 out: 258 return ret; 259 } 260 261 static void eadm_quiesce(struct subchannel *sch) 262 { 263 struct eadm_private *private = get_eadm_private(sch); 264 DECLARE_COMPLETION_ONSTACK(completion); 265 int ret; 266 267 spin_lock_irq(sch->lock); 268 if (private->state != EADM_BUSY) 269 goto disable; 270 271 if (eadm_subchannel_clear(sch)) 272 goto disable; 273 274 private->completion = &completion; 275 spin_unlock_irq(sch->lock); 276 277 wait_for_completion_io(&completion); 278 279 spin_lock_irq(sch->lock); 280 private->completion = NULL; 281 282 disable: 283 eadm_subchannel_set_timeout(sch, 0); 284 do { 285 ret = cio_disable_subchannel(sch); 286 } while (ret == -EBUSY); 287 288 spin_unlock_irq(sch->lock); 289 } 290 291 static int eadm_subchannel_remove(struct subchannel *sch) 292 { 293 struct eadm_private *private = get_eadm_private(sch); 294 295 spin_lock_irq(&list_lock); 296 list_del(&private->head); 297 spin_unlock_irq(&list_lock); 298 299 eadm_quiesce(sch); 300 301 spin_lock_irq(sch->lock); 302 set_eadm_private(sch, NULL); 303 spin_unlock_irq(sch->lock); 304 305 kfree(private); 306 307 return 0; 308 } 309 310 static void eadm_subchannel_shutdown(struct subchannel *sch) 311 { 312 eadm_quiesce(sch); 313 } 314 315 static int eadm_subchannel_freeze(struct subchannel *sch) 316 { 317 return cio_disable_subchannel(sch); 318 } 319 320 static int eadm_subchannel_restore(struct subchannel *sch) 321 { 322 return cio_enable_subchannel(sch, (u32)(unsigned long)sch); 323 } 324 325 /** 326 * eadm_subchannel_sch_event - process subchannel event 327 * @sch: subchannel 328 * @process: non-zero if function is called in process context 329 * 330 * An unspecified event occurred for this subchannel. Adjust data according 331 * to the current operational state of the subchannel. Return zero when the 332 * event has been handled sufficiently or -EAGAIN when this function should 333 * be called again in process context. 334 */ 335 static int eadm_subchannel_sch_event(struct subchannel *sch, int process) 336 { 337 struct eadm_private *private; 338 unsigned long flags; 339 int ret = 0; 340 341 spin_lock_irqsave(sch->lock, flags); 342 if (!device_is_registered(&sch->dev)) 343 goto out_unlock; 344 345 if (work_pending(&sch->todo_work)) 346 goto out_unlock; 347 348 if (cio_update_schib(sch)) { 349 css_sched_sch_todo(sch, SCH_TODO_UNREG); 350 goto out_unlock; 351 } 352 private = get_eadm_private(sch); 353 if (private->state == EADM_NOT_OPER) 354 private->state = EADM_IDLE; 355 356 out_unlock: 357 spin_unlock_irqrestore(sch->lock, flags); 358 359 return ret; 360 } 361 362 static struct css_device_id eadm_subchannel_ids[] = { 363 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_ADM, }, 364 { /* end of list */ }, 365 }; 366 MODULE_DEVICE_TABLE(css, eadm_subchannel_ids); 367 368 static struct css_driver eadm_subchannel_driver = { 369 .drv = { 370 .name = "eadm_subchannel", 371 .owner = THIS_MODULE, 372 }, 373 .subchannel_type = eadm_subchannel_ids, 374 .irq = eadm_subchannel_irq, 375 .probe = eadm_subchannel_probe, 376 .remove = eadm_subchannel_remove, 377 .shutdown = eadm_subchannel_shutdown, 378 .sch_event = eadm_subchannel_sch_event, 379 .freeze = eadm_subchannel_freeze, 380 .thaw = eadm_subchannel_restore, 381 .restore = eadm_subchannel_restore, 382 }; 383 384 static int __init eadm_sch_init(void) 385 { 386 int ret; 387 388 if (!css_general_characteristics.eadm) 389 return -ENXIO; 390 391 eadm_debug = debug_register("eadm_log", 16, 1, 16); 392 if (!eadm_debug) 393 return -ENOMEM; 394 395 debug_register_view(eadm_debug, &debug_hex_ascii_view); 396 debug_set_level(eadm_debug, 2); 397 398 isc_register(EADM_SCH_ISC); 399 ret = css_driver_register(&eadm_subchannel_driver); 400 if (ret) 401 goto cleanup; 402 403 return ret; 404 405 cleanup: 406 isc_unregister(EADM_SCH_ISC); 407 debug_unregister(eadm_debug); 408 return ret; 409 } 410 411 static void __exit eadm_sch_exit(void) 412 { 413 css_driver_unregister(&eadm_subchannel_driver); 414 isc_unregister(EADM_SCH_ISC); 415 debug_unregister(eadm_debug); 416 } 417 module_init(eadm_sch_init); 418 module_exit(eadm_sch_exit); 419