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 else 118 mod_timer(&private->timer, jiffies + expires); 119 } 120 121 static void eadm_subchannel_irq(struct subchannel *sch) 122 { 123 struct eadm_private *private = get_eadm_private(sch); 124 struct eadm_scsw *scsw = &sch->schib.scsw.eadm; 125 struct irb *irb = this_cpu_ptr(&cio_irb); 126 blk_status_t error = BLK_STS_OK; 127 128 EADM_LOG(6, "irq"); 129 EADM_LOG_HEX(6, irb, sizeof(*irb)); 130 131 inc_irq_stat(IRQIO_ADM); 132 133 if ((scsw->stctl & (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) 134 && scsw->eswf == 1 && irb->esw.eadm.erw.r) 135 error = BLK_STS_IOERR; 136 137 if (scsw->fctl & SCSW_FCTL_CLEAR_FUNC) 138 error = BLK_STS_TIMEOUT; 139 140 eadm_subchannel_set_timeout(sch, 0); 141 142 if (private->state != EADM_BUSY) { 143 EADM_LOG(1, "irq unsol"); 144 EADM_LOG_HEX(1, irb, sizeof(*irb)); 145 private->state = EADM_NOT_OPER; 146 css_sched_sch_todo(sch, SCH_TODO_EVAL); 147 return; 148 } 149 scm_irq_handler((struct aob *)(unsigned long)scsw->aob, error); 150 private->state = EADM_IDLE; 151 152 if (private->completion) 153 complete(private->completion); 154 } 155 156 static struct subchannel *eadm_get_idle_sch(void) 157 { 158 struct eadm_private *private; 159 struct subchannel *sch; 160 unsigned long flags; 161 162 spin_lock_irqsave(&list_lock, flags); 163 list_for_each_entry(private, &eadm_list, head) { 164 sch = private->sch; 165 spin_lock(sch->lock); 166 if (private->state == EADM_IDLE) { 167 private->state = EADM_BUSY; 168 list_move_tail(&private->head, &eadm_list); 169 spin_unlock(sch->lock); 170 spin_unlock_irqrestore(&list_lock, flags); 171 172 return sch; 173 } 174 spin_unlock(sch->lock); 175 } 176 spin_unlock_irqrestore(&list_lock, flags); 177 178 return NULL; 179 } 180 181 int eadm_start_aob(struct aob *aob) 182 { 183 struct eadm_private *private; 184 struct subchannel *sch; 185 unsigned long flags; 186 int ret; 187 188 sch = eadm_get_idle_sch(); 189 if (!sch) 190 return -EBUSY; 191 192 spin_lock_irqsave(sch->lock, flags); 193 eadm_subchannel_set_timeout(sch, EADM_TIMEOUT); 194 ret = eadm_subchannel_start(sch, aob); 195 if (!ret) 196 goto out_unlock; 197 198 /* Handle start subchannel failure. */ 199 eadm_subchannel_set_timeout(sch, 0); 200 private = get_eadm_private(sch); 201 private->state = EADM_NOT_OPER; 202 css_sched_sch_todo(sch, SCH_TODO_EVAL); 203 204 out_unlock: 205 spin_unlock_irqrestore(sch->lock, flags); 206 207 return ret; 208 } 209 EXPORT_SYMBOL_GPL(eadm_start_aob); 210 211 static int eadm_subchannel_probe(struct subchannel *sch) 212 { 213 struct eadm_private *private; 214 int ret; 215 216 private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); 217 if (!private) 218 return -ENOMEM; 219 220 INIT_LIST_HEAD(&private->head); 221 timer_setup(&private->timer, eadm_subchannel_timeout, 0); 222 223 spin_lock_irq(sch->lock); 224 set_eadm_private(sch, private); 225 private->state = EADM_IDLE; 226 private->sch = sch; 227 sch->isc = EADM_SCH_ISC; 228 ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); 229 if (ret) { 230 set_eadm_private(sch, NULL); 231 spin_unlock_irq(sch->lock); 232 kfree(private); 233 goto out; 234 } 235 spin_unlock_irq(sch->lock); 236 237 spin_lock_irq(&list_lock); 238 list_add(&private->head, &eadm_list); 239 spin_unlock_irq(&list_lock); 240 out: 241 return ret; 242 } 243 244 static void eadm_quiesce(struct subchannel *sch) 245 { 246 struct eadm_private *private = get_eadm_private(sch); 247 DECLARE_COMPLETION_ONSTACK(completion); 248 int ret; 249 250 spin_lock_irq(sch->lock); 251 if (private->state != EADM_BUSY) 252 goto disable; 253 254 if (eadm_subchannel_clear(sch)) 255 goto disable; 256 257 private->completion = &completion; 258 spin_unlock_irq(sch->lock); 259 260 wait_for_completion_io(&completion); 261 262 spin_lock_irq(sch->lock); 263 private->completion = NULL; 264 265 disable: 266 eadm_subchannel_set_timeout(sch, 0); 267 do { 268 ret = cio_disable_subchannel(sch); 269 } while (ret == -EBUSY); 270 271 spin_unlock_irq(sch->lock); 272 } 273 274 static void eadm_subchannel_remove(struct subchannel *sch) 275 { 276 struct eadm_private *private = get_eadm_private(sch); 277 278 spin_lock_irq(&list_lock); 279 list_del(&private->head); 280 spin_unlock_irq(&list_lock); 281 282 eadm_quiesce(sch); 283 284 spin_lock_irq(sch->lock); 285 set_eadm_private(sch, NULL); 286 spin_unlock_irq(sch->lock); 287 288 kfree(private); 289 } 290 291 static void eadm_subchannel_shutdown(struct subchannel *sch) 292 { 293 eadm_quiesce(sch); 294 } 295 296 /** 297 * eadm_subchannel_sch_event - process subchannel event 298 * @sch: subchannel 299 * @process: non-zero if function is called in process context 300 * 301 * An unspecified event occurred for this subchannel. Adjust data according 302 * to the current operational state of the subchannel. Return zero when the 303 * event has been handled sufficiently or -EAGAIN when this function should 304 * be called again in process context. 305 */ 306 static int eadm_subchannel_sch_event(struct subchannel *sch, int process) 307 { 308 struct eadm_private *private; 309 unsigned long flags; 310 311 spin_lock_irqsave(sch->lock, flags); 312 if (!device_is_registered(&sch->dev)) 313 goto out_unlock; 314 315 if (work_pending(&sch->todo_work)) 316 goto out_unlock; 317 318 if (cio_update_schib(sch)) { 319 css_sched_sch_todo(sch, SCH_TODO_UNREG); 320 goto out_unlock; 321 } 322 private = get_eadm_private(sch); 323 if (private->state == EADM_NOT_OPER) 324 private->state = EADM_IDLE; 325 326 out_unlock: 327 spin_unlock_irqrestore(sch->lock, flags); 328 329 return 0; 330 } 331 332 static struct css_device_id eadm_subchannel_ids[] = { 333 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_ADM, }, 334 { /* end of list */ }, 335 }; 336 MODULE_DEVICE_TABLE(css, eadm_subchannel_ids); 337 338 static struct css_driver eadm_subchannel_driver = { 339 .drv = { 340 .name = "eadm_subchannel", 341 .owner = THIS_MODULE, 342 }, 343 .subchannel_type = eadm_subchannel_ids, 344 .irq = eadm_subchannel_irq, 345 .probe = eadm_subchannel_probe, 346 .remove = eadm_subchannel_remove, 347 .shutdown = eadm_subchannel_shutdown, 348 .sch_event = eadm_subchannel_sch_event, 349 }; 350 351 static int __init eadm_sch_init(void) 352 { 353 int ret; 354 355 if (!css_general_characteristics.eadm) 356 return -ENXIO; 357 358 eadm_debug = debug_register("eadm_log", 16, 1, 16); 359 if (!eadm_debug) 360 return -ENOMEM; 361 362 debug_register_view(eadm_debug, &debug_hex_ascii_view); 363 debug_set_level(eadm_debug, 2); 364 365 isc_register(EADM_SCH_ISC); 366 ret = css_driver_register(&eadm_subchannel_driver); 367 if (ret) 368 goto cleanup; 369 370 return ret; 371 372 cleanup: 373 isc_unregister(EADM_SCH_ISC); 374 debug_unregister(eadm_debug); 375 return ret; 376 } 377 378 static void __exit eadm_sch_exit(void) 379 { 380 css_driver_unregister(&eadm_subchannel_driver); 381 isc_unregister(EADM_SCH_ISC); 382 debug_unregister(eadm_debug); 383 } 384 module_init(eadm_sch_init); 385 module_exit(eadm_sch_exit); 386