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