1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Driver for s390 eadm subchannels 4 * 5 * Copyright IBM Corp. 2012 6 * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com> 7 */ 8 9 #include <linux/kernel_stat.h> 10 #include <linux/completion.h> 11 #include <linux/workqueue.h> 12 #include <linux/spinlock.h> 13 #include <linux/device.h> 14 #include <linux/module.h> 15 #include <linux/timer.h> 16 #include <linux/slab.h> 17 #include <linux/list.h> 18 19 #include <asm/css_chars.h> 20 #include <asm/debug.h> 21 #include <asm/isc.h> 22 #include <asm/cio.h> 23 #include <asm/scsw.h> 24 #include <asm/eadm.h> 25 26 #include "eadm_sch.h" 27 #include "ioasm.h" 28 #include "cio.h" 29 #include "css.h" 30 #include "orb.h" 31 32 MODULE_DESCRIPTION("driver for s390 eadm subchannels"); 33 MODULE_LICENSE("GPL"); 34 35 #define EADM_TIMEOUT (7 * HZ) 36 static DEFINE_SPINLOCK(list_lock); 37 static LIST_HEAD(eadm_list); 38 39 static debug_info_t *eadm_debug; 40 41 #define EADM_LOG(imp, txt) do { \ 42 debug_text_event(eadm_debug, imp, txt); \ 43 } while (0) 44 45 static void EADM_LOG_HEX(int level, void *data, int length) 46 { 47 debug_event(eadm_debug, level, data, length); 48 } 49 50 static void orb_init(union orb *orb) 51 { 52 memset(orb, 0, sizeof(union orb)); 53 orb->eadm.compat1 = 1; 54 orb->eadm.compat2 = 1; 55 orb->eadm.fmt = 1; 56 orb->eadm.x = 1; 57 } 58 59 static int eadm_subchannel_start(struct subchannel *sch, struct aob *aob) 60 { 61 union orb *orb = &get_eadm_private(sch)->orb; 62 int cc; 63 64 orb_init(orb); 65 orb->eadm.aob = (u32)__pa(aob); 66 orb->eadm.intparm = (u32)(addr_t)sch; 67 orb->eadm.key = PAGE_DEFAULT_KEY >> 4; 68 69 EADM_LOG(6, "start"); 70 EADM_LOG_HEX(6, &sch->schid, sizeof(sch->schid)); 71 72 cc = ssch(sch->schid, orb); 73 switch (cc) { 74 case 0: 75 sch->schib.scsw.eadm.actl |= SCSW_ACTL_START_PEND; 76 break; 77 case 1: /* status pending */ 78 case 2: /* busy */ 79 return -EBUSY; 80 case 3: /* not operational */ 81 return -ENODEV; 82 } 83 return 0; 84 } 85 86 static int eadm_subchannel_clear(struct subchannel *sch) 87 { 88 int cc; 89 90 cc = csch(sch->schid); 91 if (cc) 92 return -ENODEV; 93 94 sch->schib.scsw.eadm.actl |= SCSW_ACTL_CLEAR_PEND; 95 return 0; 96 } 97 98 static void eadm_subchannel_timeout(struct timer_list *t) 99 { 100 struct eadm_private *private = from_timer(private, t, timer); 101 struct subchannel *sch = private->sch; 102 103 spin_lock_irq(sch->lock); 104 EADM_LOG(1, "timeout"); 105 EADM_LOG_HEX(1, &sch->schid, sizeof(sch->schid)); 106 if (eadm_subchannel_clear(sch)) 107 EADM_LOG(0, "clear failed"); 108 spin_unlock_irq(sch->lock); 109 } 110 111 static void eadm_subchannel_set_timeout(struct subchannel *sch, int expires) 112 { 113 struct eadm_private *private = get_eadm_private(sch); 114 115 if (expires == 0) { 116 del_timer(&private->timer); 117 return; 118 } 119 if (timer_pending(&private->timer)) { 120 if (mod_timer(&private->timer, jiffies + expires)) 121 return; 122 } 123 private->timer.expires = jiffies + expires; 124 add_timer(&private->timer); 125 } 126 127 static void eadm_subchannel_irq(struct subchannel *sch) 128 { 129 struct eadm_private *private = get_eadm_private(sch); 130 struct eadm_scsw *scsw = &sch->schib.scsw.eadm; 131 struct irb *irb = this_cpu_ptr(&cio_irb); 132 blk_status_t error = BLK_STS_OK; 133 134 EADM_LOG(6, "irq"); 135 EADM_LOG_HEX(6, irb, sizeof(*irb)); 136 137 inc_irq_stat(IRQIO_ADM); 138 139 if ((scsw->stctl & (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) 140 && scsw->eswf == 1 && irb->esw.eadm.erw.r) 141 error = BLK_STS_IOERR; 142 143 if (scsw->fctl & SCSW_FCTL_CLEAR_FUNC) 144 error = BLK_STS_TIMEOUT; 145 146 eadm_subchannel_set_timeout(sch, 0); 147 148 if (private->state != EADM_BUSY) { 149 EADM_LOG(1, "irq unsol"); 150 EADM_LOG_HEX(1, irb, sizeof(*irb)); 151 private->state = EADM_NOT_OPER; 152 css_sched_sch_todo(sch, SCH_TODO_EVAL); 153 return; 154 } 155 scm_irq_handler((struct aob *)(unsigned long)scsw->aob, error); 156 private->state = EADM_IDLE; 157 158 if (private->completion) 159 complete(private->completion); 160 } 161 162 static struct subchannel *eadm_get_idle_sch(void) 163 { 164 struct eadm_private *private; 165 struct subchannel *sch; 166 unsigned long flags; 167 168 spin_lock_irqsave(&list_lock, flags); 169 list_for_each_entry(private, &eadm_list, head) { 170 sch = private->sch; 171 spin_lock(sch->lock); 172 if (private->state == EADM_IDLE) { 173 private->state = EADM_BUSY; 174 list_move_tail(&private->head, &eadm_list); 175 spin_unlock(sch->lock); 176 spin_unlock_irqrestore(&list_lock, flags); 177 178 return sch; 179 } 180 spin_unlock(sch->lock); 181 } 182 spin_unlock_irqrestore(&list_lock, flags); 183 184 return NULL; 185 } 186 187 int eadm_start_aob(struct aob *aob) 188 { 189 struct eadm_private *private; 190 struct subchannel *sch; 191 unsigned long flags; 192 int ret; 193 194 sch = eadm_get_idle_sch(); 195 if (!sch) 196 return -EBUSY; 197 198 spin_lock_irqsave(sch->lock, flags); 199 eadm_subchannel_set_timeout(sch, EADM_TIMEOUT); 200 ret = eadm_subchannel_start(sch, aob); 201 if (!ret) 202 goto out_unlock; 203 204 /* Handle start subchannel failure. */ 205 eadm_subchannel_set_timeout(sch, 0); 206 private = get_eadm_private(sch); 207 private->state = EADM_NOT_OPER; 208 css_sched_sch_todo(sch, SCH_TODO_EVAL); 209 210 out_unlock: 211 spin_unlock_irqrestore(sch->lock, flags); 212 213 return ret; 214 } 215 EXPORT_SYMBOL_GPL(eadm_start_aob); 216 217 static int eadm_subchannel_probe(struct subchannel *sch) 218 { 219 struct eadm_private *private; 220 int ret; 221 222 private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); 223 if (!private) 224 return -ENOMEM; 225 226 INIT_LIST_HEAD(&private->head); 227 timer_setup(&private->timer, eadm_subchannel_timeout, 0); 228 229 spin_lock_irq(sch->lock); 230 set_eadm_private(sch, private); 231 private->state = EADM_IDLE; 232 private->sch = sch; 233 sch->isc = EADM_SCH_ISC; 234 ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); 235 if (ret) { 236 set_eadm_private(sch, NULL); 237 spin_unlock_irq(sch->lock); 238 kfree(private); 239 goto out; 240 } 241 spin_unlock_irq(sch->lock); 242 243 spin_lock_irq(&list_lock); 244 list_add(&private->head, &eadm_list); 245 spin_unlock_irq(&list_lock); 246 out: 247 return ret; 248 } 249 250 static void eadm_quiesce(struct subchannel *sch) 251 { 252 struct eadm_private *private = get_eadm_private(sch); 253 DECLARE_COMPLETION_ONSTACK(completion); 254 int ret; 255 256 spin_lock_irq(sch->lock); 257 if (private->state != EADM_BUSY) 258 goto disable; 259 260 if (eadm_subchannel_clear(sch)) 261 goto disable; 262 263 private->completion = &completion; 264 spin_unlock_irq(sch->lock); 265 266 wait_for_completion_io(&completion); 267 268 spin_lock_irq(sch->lock); 269 private->completion = NULL; 270 271 disable: 272 eadm_subchannel_set_timeout(sch, 0); 273 do { 274 ret = cio_disable_subchannel(sch); 275 } while (ret == -EBUSY); 276 277 spin_unlock_irq(sch->lock); 278 } 279 280 static void eadm_subchannel_remove(struct subchannel *sch) 281 { 282 struct eadm_private *private = get_eadm_private(sch); 283 284 spin_lock_irq(&list_lock); 285 list_del(&private->head); 286 spin_unlock_irq(&list_lock); 287 288 eadm_quiesce(sch); 289 290 spin_lock_irq(sch->lock); 291 set_eadm_private(sch, NULL); 292 spin_unlock_irq(sch->lock); 293 294 kfree(private); 295 } 296 297 static void eadm_subchannel_shutdown(struct subchannel *sch) 298 { 299 eadm_quiesce(sch); 300 } 301 302 /** 303 * eadm_subchannel_sch_event - process subchannel event 304 * @sch: subchannel 305 * @process: non-zero if function is called in process context 306 * 307 * An unspecified event occurred for this subchannel. Adjust data according 308 * to the current operational state of the subchannel. Return zero when the 309 * event has been handled sufficiently or -EAGAIN when this function should 310 * be called again in process context. 311 */ 312 static int eadm_subchannel_sch_event(struct subchannel *sch, int process) 313 { 314 struct eadm_private *private; 315 unsigned long flags; 316 317 spin_lock_irqsave(sch->lock, flags); 318 if (!device_is_registered(&sch->dev)) 319 goto out_unlock; 320 321 if (work_pending(&sch->todo_work)) 322 goto out_unlock; 323 324 if (cio_update_schib(sch)) { 325 css_sched_sch_todo(sch, SCH_TODO_UNREG); 326 goto out_unlock; 327 } 328 private = get_eadm_private(sch); 329 if (private->state == EADM_NOT_OPER) 330 private->state = EADM_IDLE; 331 332 out_unlock: 333 spin_unlock_irqrestore(sch->lock, flags); 334 335 return 0; 336 } 337 338 static struct css_device_id eadm_subchannel_ids[] = { 339 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_ADM, }, 340 { /* end of list */ }, 341 }; 342 MODULE_DEVICE_TABLE(css, eadm_subchannel_ids); 343 344 static struct css_driver eadm_subchannel_driver = { 345 .drv = { 346 .name = "eadm_subchannel", 347 .owner = THIS_MODULE, 348 }, 349 .subchannel_type = eadm_subchannel_ids, 350 .irq = eadm_subchannel_irq, 351 .probe = eadm_subchannel_probe, 352 .remove = eadm_subchannel_remove, 353 .shutdown = eadm_subchannel_shutdown, 354 .sch_event = eadm_subchannel_sch_event, 355 }; 356 357 static int __init eadm_sch_init(void) 358 { 359 int ret; 360 361 if (!css_general_characteristics.eadm) 362 return -ENXIO; 363 364 eadm_debug = debug_register("eadm_log", 16, 1, 16); 365 if (!eadm_debug) 366 return -ENOMEM; 367 368 debug_register_view(eadm_debug, &debug_hex_ascii_view); 369 debug_set_level(eadm_debug, 2); 370 371 isc_register(EADM_SCH_ISC); 372 ret = css_driver_register(&eadm_subchannel_driver); 373 if (ret) 374 goto cleanup; 375 376 return ret; 377 378 cleanup: 379 isc_unregister(EADM_SCH_ISC); 380 debug_unregister(eadm_debug); 381 return ret; 382 } 383 384 static void __exit eadm_sch_exit(void) 385 { 386 css_driver_unregister(&eadm_subchannel_driver); 387 isc_unregister(EADM_SCH_ISC); 388 debug_unregister(eadm_debug); 389 } 390 module_init(eadm_sch_init); 391 module_exit(eadm_sch_exit); 392