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/export.h> 15 #include <linux/module.h> 16 #include <linux/timer.h> 17 #include <linux/slab.h> 18 #include <linux/list.h> 19 #include <linux/io.h> 20 21 #include <asm/css_chars.h> 22 #include <asm/debug.h> 23 #include <asm/isc.h> 24 #include <asm/cio.h> 25 #include <asm/scsw.h> 26 #include <asm/eadm.h> 27 28 #include "eadm_sch.h" 29 #include "ioasm.h" 30 #include "cio.h" 31 #include "css.h" 32 #include "orb.h" 33 34 MODULE_DESCRIPTION("driver for s390 eadm subchannels"); 35 MODULE_LICENSE("GPL"); 36 37 #define EADM_TIMEOUT (7 * HZ) 38 static DEFINE_SPINLOCK(list_lock); 39 static LIST_HEAD(eadm_list); 40 41 static debug_info_t *eadm_debug; 42 43 #define EADM_LOG(imp, txt) do { \ 44 debug_text_event(eadm_debug, imp, txt); \ 45 } while (0) 46 47 static void EADM_LOG_HEX(int level, void *data, int length) 48 { 49 debug_event(eadm_debug, level, data, length); 50 } 51 52 static void orb_init(union orb *orb) 53 { 54 memset(orb, 0, sizeof(union orb)); 55 orb->eadm.compat1 = 1; 56 orb->eadm.compat2 = 1; 57 orb->eadm.fmt = 1; 58 orb->eadm.x = 1; 59 } 60 61 static int eadm_subchannel_start(struct subchannel *sch, struct aob *aob) 62 { 63 union orb *orb = &get_eadm_private(sch)->orb; 64 int cc; 65 66 orb_init(orb); 67 orb->eadm.aob = virt_to_dma32(aob); 68 orb->eadm.intparm = (u32)virt_to_phys(sch); 69 orb->eadm.key = PAGE_DEFAULT_KEY >> 4; 70 71 EADM_LOG(6, "start"); 72 EADM_LOG_HEX(6, &sch->schid, sizeof(sch->schid)); 73 74 cc = ssch(sch->schid, orb); 75 switch (cc) { 76 case 0: 77 sch->schib.scsw.eadm.actl |= SCSW_ACTL_START_PEND; 78 break; 79 case 1: /* status pending */ 80 case 2: /* busy */ 81 return -EBUSY; 82 case 3: /* not operational */ 83 return -ENODEV; 84 } 85 return 0; 86 } 87 88 static int eadm_subchannel_clear(struct subchannel *sch) 89 { 90 int cc; 91 92 cc = csch(sch->schid); 93 if (cc) 94 return -ENODEV; 95 96 sch->schib.scsw.eadm.actl |= SCSW_ACTL_CLEAR_PEND; 97 return 0; 98 } 99 100 static void eadm_subchannel_timeout(struct timer_list *t) 101 { 102 struct eadm_private *private = timer_container_of(private, t, timer); 103 struct subchannel *sch = private->sch; 104 105 spin_lock_irq(&sch->lock); 106 EADM_LOG(1, "timeout"); 107 EADM_LOG_HEX(1, &sch->schid, sizeof(sch->schid)); 108 if (eadm_subchannel_clear(sch)) 109 EADM_LOG(0, "clear failed"); 110 spin_unlock_irq(&sch->lock); 111 } 112 113 static void eadm_subchannel_set_timeout(struct subchannel *sch, int expires) 114 { 115 struct eadm_private *private = get_eadm_private(sch); 116 117 if (expires == 0) 118 timer_delete(&private->timer); 119 else 120 mod_timer(&private->timer, jiffies + expires); 121 } 122 123 static void eadm_subchannel_irq(struct subchannel *sch) 124 { 125 struct eadm_private *private = get_eadm_private(sch); 126 struct eadm_scsw *scsw = &sch->schib.scsw.eadm; 127 struct irb *irb = this_cpu_ptr(&cio_irb); 128 blk_status_t error = BLK_STS_OK; 129 130 EADM_LOG(6, "irq"); 131 EADM_LOG_HEX(6, irb, sizeof(*irb)); 132 133 inc_irq_stat(IRQIO_ADM); 134 135 if ((scsw->stctl & (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) 136 && scsw->eswf == 1 && irb->esw.eadm.erw.r) 137 error = BLK_STS_IOERR; 138 139 if (scsw->fctl & SCSW_FCTL_CLEAR_FUNC) 140 error = BLK_STS_TIMEOUT; 141 142 eadm_subchannel_set_timeout(sch, 0); 143 144 if (private->state != EADM_BUSY) { 145 EADM_LOG(1, "irq unsol"); 146 EADM_LOG_HEX(1, irb, sizeof(*irb)); 147 private->state = EADM_NOT_OPER; 148 css_sched_sch_todo(sch, SCH_TODO_EVAL); 149 return; 150 } 151 scm_irq_handler(dma32_to_virt(scsw->aob), error); 152 private->state = EADM_IDLE; 153 154 if (private->completion) 155 complete(private->completion); 156 } 157 158 static struct subchannel *eadm_get_idle_sch(void) 159 { 160 struct eadm_private *private; 161 struct subchannel *sch; 162 unsigned long flags; 163 164 spin_lock_irqsave(&list_lock, flags); 165 list_for_each_entry(private, &eadm_list, head) { 166 sch = private->sch; 167 spin_lock(&sch->lock); 168 if (private->state == EADM_IDLE) { 169 private->state = EADM_BUSY; 170 list_move_tail(&private->head, &eadm_list); 171 spin_unlock(&sch->lock); 172 spin_unlock_irqrestore(&list_lock, flags); 173 174 return sch; 175 } 176 spin_unlock(&sch->lock); 177 } 178 spin_unlock_irqrestore(&list_lock, flags); 179 180 return NULL; 181 } 182 183 int eadm_start_aob(struct aob *aob) 184 { 185 struct eadm_private *private; 186 struct subchannel *sch; 187 unsigned long flags; 188 int ret; 189 190 sch = eadm_get_idle_sch(); 191 if (!sch) 192 return -EBUSY; 193 194 spin_lock_irqsave(&sch->lock, flags); 195 eadm_subchannel_set_timeout(sch, EADM_TIMEOUT); 196 ret = eadm_subchannel_start(sch, aob); 197 if (!ret) 198 goto out_unlock; 199 200 /* Handle start subchannel failure. */ 201 eadm_subchannel_set_timeout(sch, 0); 202 private = get_eadm_private(sch); 203 private->state = EADM_NOT_OPER; 204 css_sched_sch_todo(sch, SCH_TODO_EVAL); 205 206 out_unlock: 207 spin_unlock_irqrestore(&sch->lock, flags); 208 209 return ret; 210 } 211 EXPORT_SYMBOL_GPL(eadm_start_aob); 212 213 static int eadm_subchannel_probe(struct subchannel *sch) 214 { 215 struct eadm_private *private; 216 int ret; 217 218 private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); 219 if (!private) 220 return -ENOMEM; 221 222 INIT_LIST_HEAD(&private->head); 223 timer_setup(&private->timer, eadm_subchannel_timeout, 0); 224 225 spin_lock_irq(&sch->lock); 226 set_eadm_private(sch, private); 227 private->state = EADM_IDLE; 228 private->sch = sch; 229 sch->isc = EADM_SCH_ISC; 230 ret = cio_enable_subchannel(sch, (u32)virt_to_phys(sch)); 231 if (ret) { 232 set_eadm_private(sch, NULL); 233 spin_unlock_irq(&sch->lock); 234 kfree(private); 235 goto out; 236 } 237 spin_unlock_irq(&sch->lock); 238 239 spin_lock_irq(&list_lock); 240 list_add(&private->head, &eadm_list); 241 spin_unlock_irq(&list_lock); 242 out: 243 return ret; 244 } 245 246 static void eadm_quiesce(struct subchannel *sch) 247 { 248 struct eadm_private *private = get_eadm_private(sch); 249 DECLARE_COMPLETION_ONSTACK(completion); 250 int ret; 251 252 spin_lock_irq(&sch->lock); 253 if (private->state != EADM_BUSY) 254 goto disable; 255 256 if (eadm_subchannel_clear(sch)) 257 goto disable; 258 259 private->completion = &completion; 260 spin_unlock_irq(&sch->lock); 261 262 wait_for_completion_io(&completion); 263 264 spin_lock_irq(&sch->lock); 265 private->completion = NULL; 266 267 disable: 268 eadm_subchannel_set_timeout(sch, 0); 269 do { 270 ret = cio_disable_subchannel(sch); 271 } while (ret == -EBUSY); 272 273 spin_unlock_irq(&sch->lock); 274 } 275 276 static void eadm_subchannel_remove(struct subchannel *sch) 277 { 278 struct eadm_private *private = get_eadm_private(sch); 279 280 spin_lock_irq(&list_lock); 281 list_del(&private->head); 282 spin_unlock_irq(&list_lock); 283 284 eadm_quiesce(sch); 285 286 spin_lock_irq(&sch->lock); 287 set_eadm_private(sch, NULL); 288 spin_unlock_irq(&sch->lock); 289 290 kfree(private); 291 } 292 293 static void eadm_subchannel_shutdown(struct subchannel *sch) 294 { 295 eadm_quiesce(sch); 296 } 297 298 /** 299 * eadm_subchannel_sch_event - process subchannel event 300 * @sch: subchannel 301 * @process: non-zero if function is called in process context 302 * 303 * An unspecified event occurred for this subchannel. Adjust data according 304 * to the current operational state of the subchannel. Return zero when the 305 * event has been handled sufficiently or -EAGAIN when this function should 306 * be called again in process context. 307 */ 308 static int eadm_subchannel_sch_event(struct subchannel *sch, int process) 309 { 310 struct eadm_private *private; 311 unsigned long flags; 312 313 spin_lock_irqsave(&sch->lock, flags); 314 if (!device_is_registered(&sch->dev)) 315 goto out_unlock; 316 317 if (work_pending(&sch->todo_work)) 318 goto out_unlock; 319 320 if (cio_update_schib(sch)) { 321 css_sched_sch_todo(sch, SCH_TODO_UNREG); 322 goto out_unlock; 323 } 324 private = get_eadm_private(sch); 325 if (private->state == EADM_NOT_OPER) 326 private->state = EADM_IDLE; 327 328 out_unlock: 329 spin_unlock_irqrestore(&sch->lock, flags); 330 331 return 0; 332 } 333 334 static struct css_device_id eadm_subchannel_ids[] = { 335 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_ADM, }, 336 { /* end of list */ }, 337 }; 338 MODULE_DEVICE_TABLE(css, eadm_subchannel_ids); 339 340 static struct css_driver eadm_subchannel_driver = { 341 .drv = { 342 .name = "eadm_subchannel", 343 .owner = THIS_MODULE, 344 }, 345 .subchannel_type = eadm_subchannel_ids, 346 .irq = eadm_subchannel_irq, 347 .probe = eadm_subchannel_probe, 348 .remove = eadm_subchannel_remove, 349 .shutdown = eadm_subchannel_shutdown, 350 .sch_event = eadm_subchannel_sch_event, 351 }; 352 353 static int __init eadm_sch_init(void) 354 { 355 int ret; 356 357 if (!css_general_characteristics.eadm) 358 return -ENXIO; 359 360 eadm_debug = debug_register("eadm_log", 16, 1, 16); 361 if (!eadm_debug) 362 return -ENOMEM; 363 364 debug_register_view(eadm_debug, &debug_hex_ascii_view); 365 debug_set_level(eadm_debug, 2); 366 367 isc_register(EADM_SCH_ISC); 368 ret = css_driver_register(&eadm_subchannel_driver); 369 if (ret) 370 goto cleanup; 371 372 return ret; 373 374 cleanup: 375 isc_unregister(EADM_SCH_ISC); 376 debug_unregister(eadm_debug); 377 return ret; 378 } 379 380 static void __exit eadm_sch_exit(void) 381 { 382 css_driver_unregister(&eadm_subchannel_driver); 383 isc_unregister(EADM_SCH_ISC); 384 debug_unregister(eadm_debug); 385 } 386 module_init(eadm_sch_init); 387 module_exit(eadm_sch_exit); 388