xref: /openbmc/linux/net/iucv/iucv.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  * IUCV base infrastructure.
3  *
4  * Copyright 2001, 2006 IBM Deutschland Entwicklung GmbH, IBM Corporation
5  * Author(s):
6  *    Original source:
7  *	Alan Altmark (Alan_Altmark@us.ibm.com)	Sept. 2000
8  *	Xenia Tkatschow (xenia@us.ibm.com)
9  *    2Gb awareness and general cleanup:
10  *	Fritz Elfert (elfert@de.ibm.com, felfert@millenux.com)
11  *    Rewritten for af_iucv:
12  *	Martin Schwidefsky <schwidefsky@de.ibm.com>
13  *
14  * Documentation used:
15  *    The original source
16  *    CP Programming Service, IBM document # SC24-5760
17  *
18  * This program is free software; you can redistribute it and/or modify
19  * it under the terms of the GNU General Public License as published by
20  * the Free Software Foundation; either version 2, or (at your option)
21  * any later version.
22  *
23  * This program is distributed in the hope that it will be useful,
24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
26  * GNU General Public License for more details.
27  *
28  * You should have received a copy of the GNU General Public License
29  * along with this program; if not, write to the Free Software
30  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
31  */
32 
33 #include <linux/module.h>
34 #include <linux/moduleparam.h>
35 #include <linux/spinlock.h>
36 #include <linux/kernel.h>
37 #include <linux/slab.h>
38 #include <linux/init.h>
39 #include <linux/interrupt.h>
40 #include <linux/list.h>
41 #include <linux/errno.h>
42 #include <linux/err.h>
43 #include <linux/device.h>
44 #include <linux/cpu.h>
45 #include <net/iucv/iucv.h>
46 #include <asm/atomic.h>
47 #include <asm/ebcdic.h>
48 #include <asm/io.h>
49 #include <asm/s390_ext.h>
50 #include <asm/s390_rdev.h>
51 #include <asm/smp.h>
52 
53 /*
54  * FLAGS:
55  * All flags are defined in the field IPFLAGS1 of each function
56  * and can be found in CP Programming Services.
57  * IPSRCCLS - Indicates you have specified a source class.
58  * IPTRGCLS - Indicates you have specified a target class.
59  * IPFGPID  - Indicates you have specified a pathid.
60  * IPFGMID  - Indicates you have specified a message ID.
61  * IPNORPY  - Indicates a one-way message. No reply expected.
62  * IPALL    - Indicates that all paths are affected.
63  */
64 #define IUCV_IPSRCCLS	0x01
65 #define IUCV_IPTRGCLS	0x01
66 #define IUCV_IPFGPID	0x02
67 #define IUCV_IPFGMID	0x04
68 #define IUCV_IPNORPY	0x10
69 #define IUCV_IPALL	0x80
70 
71 static int iucv_bus_match(struct device *dev, struct device_driver *drv)
72 {
73 	return 0;
74 }
75 
76 struct bus_type iucv_bus = {
77 	.name = "iucv",
78 	.match = iucv_bus_match,
79 };
80 EXPORT_SYMBOL(iucv_bus);
81 
82 struct device *iucv_root;
83 EXPORT_SYMBOL(iucv_root);
84 
85 static int iucv_available;
86 
87 /* General IUCV interrupt structure */
88 struct iucv_irq_data {
89 	u16 ippathid;
90 	u8  ipflags1;
91 	u8  iptype;
92 	u32 res2[8];
93 };
94 
95 struct iucv_irq_list {
96 	struct list_head list;
97 	struct iucv_irq_data data;
98 };
99 
100 static struct iucv_irq_data *iucv_irq_data;
101 static cpumask_t iucv_buffer_cpumask = CPU_MASK_NONE;
102 static cpumask_t iucv_irq_cpumask = CPU_MASK_NONE;
103 
104 /*
105  * Queue of interrupt buffers lock for delivery via the tasklet
106  * (fast but can't call smp_call_function).
107  */
108 static LIST_HEAD(iucv_task_queue);
109 
110 /*
111  * The tasklet for fast delivery of iucv interrupts.
112  */
113 static void iucv_tasklet_fn(unsigned long);
114 static DECLARE_TASKLET(iucv_tasklet, iucv_tasklet_fn,0);
115 
116 /*
117  * Queue of interrupt buffers for delivery via a work queue
118  * (slower but can call smp_call_function).
119  */
120 static LIST_HEAD(iucv_work_queue);
121 
122 /*
123  * The work element to deliver path pending interrupts.
124  */
125 static void iucv_work_fn(struct work_struct *work);
126 static DECLARE_WORK(iucv_work, iucv_work_fn);
127 
128 /*
129  * Spinlock protecting task and work queue.
130  */
131 static DEFINE_SPINLOCK(iucv_queue_lock);
132 
133 enum iucv_command_codes {
134 	IUCV_QUERY = 0,
135 	IUCV_RETRIEVE_BUFFER = 2,
136 	IUCV_SEND = 4,
137 	IUCV_RECEIVE = 5,
138 	IUCV_REPLY = 6,
139 	IUCV_REJECT = 8,
140 	IUCV_PURGE = 9,
141 	IUCV_ACCEPT = 10,
142 	IUCV_CONNECT = 11,
143 	IUCV_DECLARE_BUFFER = 12,
144 	IUCV_QUIESCE = 13,
145 	IUCV_RESUME = 14,
146 	IUCV_SEVER = 15,
147 	IUCV_SETMASK = 16,
148 };
149 
150 /*
151  * Error messages that are used with the iucv_sever function. They get
152  * converted to EBCDIC.
153  */
154 static char iucv_error_no_listener[16] = "NO LISTENER";
155 static char iucv_error_no_memory[16] = "NO MEMORY";
156 static char iucv_error_pathid[16] = "INVALID PATHID";
157 
158 /*
159  * iucv_handler_list: List of registered handlers.
160  */
161 static LIST_HEAD(iucv_handler_list);
162 
163 /*
164  * iucv_path_table: an array of iucv_path structures.
165  */
166 static struct iucv_path **iucv_path_table;
167 static unsigned long iucv_max_pathid;
168 
169 /*
170  * iucv_lock: spinlock protecting iucv_handler_list and iucv_pathid_table
171  */
172 static DEFINE_SPINLOCK(iucv_table_lock);
173 
174 /*
175  * iucv_active_cpu: contains the number of the cpu executing the tasklet
176  * or the work handler. Needed for iucv_path_sever called from tasklet.
177  */
178 static int iucv_active_cpu = -1;
179 
180 /*
181  * Mutex and wait queue for iucv_register/iucv_unregister.
182  */
183 static DEFINE_MUTEX(iucv_register_mutex);
184 
185 /*
186  * Counter for number of non-smp capable handlers.
187  */
188 static int iucv_nonsmp_handler;
189 
190 /*
191  * IUCV control data structure. Used by iucv_path_accept, iucv_path_connect,
192  * iucv_path_quiesce and iucv_path_sever.
193  */
194 struct iucv_cmd_control {
195 	u16 ippathid;
196 	u8  ipflags1;
197 	u8  iprcode;
198 	u16 ipmsglim;
199 	u16 res1;
200 	u8  ipvmid[8];
201 	u8  ipuser[16];
202 	u8  iptarget[8];
203 } __attribute__ ((packed,aligned(8)));
204 
205 /*
206  * Data in parameter list iucv structure. Used by iucv_message_send,
207  * iucv_message_send2way and iucv_message_reply.
208  */
209 struct iucv_cmd_dpl {
210 	u16 ippathid;
211 	u8  ipflags1;
212 	u8  iprcode;
213 	u32 ipmsgid;
214 	u32 iptrgcls;
215 	u8  iprmmsg[8];
216 	u32 ipsrccls;
217 	u32 ipmsgtag;
218 	u32 ipbfadr2;
219 	u32 ipbfln2f;
220 	u32 res;
221 } __attribute__ ((packed,aligned(8)));
222 
223 /*
224  * Data in buffer iucv structure. Used by iucv_message_receive,
225  * iucv_message_reject, iucv_message_send, iucv_message_send2way
226  * and iucv_declare_cpu.
227  */
228 struct iucv_cmd_db {
229 	u16 ippathid;
230 	u8  ipflags1;
231 	u8  iprcode;
232 	u32 ipmsgid;
233 	u32 iptrgcls;
234 	u32 ipbfadr1;
235 	u32 ipbfln1f;
236 	u32 ipsrccls;
237 	u32 ipmsgtag;
238 	u32 ipbfadr2;
239 	u32 ipbfln2f;
240 	u32 res;
241 } __attribute__ ((packed,aligned(8)));
242 
243 /*
244  * Purge message iucv structure. Used by iucv_message_purge.
245  */
246 struct iucv_cmd_purge {
247 	u16 ippathid;
248 	u8  ipflags1;
249 	u8  iprcode;
250 	u32 ipmsgid;
251 	u8  ipaudit[3];
252 	u8  res1[5];
253 	u32 res2;
254 	u32 ipsrccls;
255 	u32 ipmsgtag;
256 	u32 res3[3];
257 } __attribute__ ((packed,aligned(8)));
258 
259 /*
260  * Set mask iucv structure. Used by iucv_enable_cpu.
261  */
262 struct iucv_cmd_set_mask {
263 	u8  ipmask;
264 	u8  res1[2];
265 	u8  iprcode;
266 	u32 res2[9];
267 } __attribute__ ((packed,aligned(8)));
268 
269 union iucv_param {
270 	struct iucv_cmd_control ctrl;
271 	struct iucv_cmd_dpl dpl;
272 	struct iucv_cmd_db db;
273 	struct iucv_cmd_purge purge;
274 	struct iucv_cmd_set_mask set_mask;
275 };
276 
277 /*
278  * Anchor for per-cpu IUCV command parameter block.
279  */
280 static union iucv_param *iucv_param;
281 
282 /**
283  * iucv_call_b2f0
284  * @code: identifier of IUCV call to CP.
285  * @parm: pointer to a struct iucv_parm block
286  *
287  * Calls CP to execute IUCV commands.
288  *
289  * Returns the result of the CP IUCV call.
290  */
291 static inline int iucv_call_b2f0(int command, union iucv_param *parm)
292 {
293 	register unsigned long reg0 asm ("0");
294 	register unsigned long reg1 asm ("1");
295 	int ccode;
296 
297 	reg0 = command;
298 	reg1 = virt_to_phys(parm);
299 	asm volatile(
300 		"	.long 0xb2f01000\n"
301 		"	ipm	%0\n"
302 		"	srl	%0,28\n"
303 		: "=d" (ccode), "=m" (*parm), "+d" (reg0), "+a" (reg1)
304 		:  "m" (*parm) : "cc");
305 	return (ccode == 1) ? parm->ctrl.iprcode : ccode;
306 }
307 
308 /**
309  * iucv_query_maxconn
310  *
311  * Determines the maximum number of connections that may be established.
312  *
313  * Returns the maximum number of connections or -EPERM is IUCV is not
314  * available.
315  */
316 static int iucv_query_maxconn(void)
317 {
318 	register unsigned long reg0 asm ("0");
319 	register unsigned long reg1 asm ("1");
320 	void *param;
321 	int ccode;
322 
323 	param = kzalloc(sizeof(union iucv_param), GFP_KERNEL|GFP_DMA);
324 	if (!param)
325 		return -ENOMEM;
326 	reg0 = IUCV_QUERY;
327 	reg1 = (unsigned long) param;
328 	asm volatile (
329 		"	.long	0xb2f01000\n"
330 		"	ipm	%0\n"
331 		"	srl	%0,28\n"
332 		: "=d" (ccode), "+d" (reg0), "+d" (reg1) : : "cc");
333 	if (ccode == 0)
334 		iucv_max_pathid = reg0;
335 	kfree(param);
336 	return ccode ? -EPERM : 0;
337 }
338 
339 /**
340  * iucv_allow_cpu
341  * @data: unused
342  *
343  * Allow iucv interrupts on this cpu.
344  */
345 static void iucv_allow_cpu(void *data)
346 {
347 	int cpu = smp_processor_id();
348 	union iucv_param *parm;
349 
350 	/*
351 	 * Enable all iucv interrupts.
352 	 * ipmask contains bits for the different interrupts
353 	 *	0x80 - Flag to allow nonpriority message pending interrupts
354 	 *	0x40 - Flag to allow priority message pending interrupts
355 	 *	0x20 - Flag to allow nonpriority message completion interrupts
356 	 *	0x10 - Flag to allow priority message completion interrupts
357 	 *	0x08 - Flag to allow IUCV control interrupts
358 	 */
359 	parm = percpu_ptr(iucv_param, smp_processor_id());
360 	memset(parm, 0, sizeof(union iucv_param));
361 	parm->set_mask.ipmask = 0xf8;
362 	iucv_call_b2f0(IUCV_SETMASK, parm);
363 
364 	/* Set indication that iucv interrupts are allowed for this cpu. */
365 	cpu_set(cpu, iucv_irq_cpumask);
366 }
367 
368 /**
369  * iucv_block_cpu
370  * @data: unused
371  *
372  * Block iucv interrupts on this cpu.
373  */
374 static void iucv_block_cpu(void *data)
375 {
376 	int cpu = smp_processor_id();
377 	union iucv_param *parm;
378 
379 	/* Disable all iucv interrupts. */
380 	parm = percpu_ptr(iucv_param, smp_processor_id());
381 	memset(parm, 0, sizeof(union iucv_param));
382 	iucv_call_b2f0(IUCV_SETMASK, parm);
383 
384 	/* Clear indication that iucv interrupts are allowed for this cpu. */
385 	cpu_clear(cpu, iucv_irq_cpumask);
386 }
387 
388 /**
389  * iucv_declare_cpu
390  * @data: unused
391  *
392  * Declare a interrupt buffer on this cpu.
393  */
394 static void iucv_declare_cpu(void *data)
395 {
396 	int cpu = smp_processor_id();
397 	union iucv_param *parm;
398 	int rc;
399 
400 	if (cpu_isset(cpu, iucv_buffer_cpumask))
401 		return;
402 
403 	/* Declare interrupt buffer. */
404 	parm = percpu_ptr(iucv_param, cpu);
405 	memset(parm, 0, sizeof(union iucv_param));
406 	parm->db.ipbfadr1 = virt_to_phys(percpu_ptr(iucv_irq_data, cpu));
407 	rc = iucv_call_b2f0(IUCV_DECLARE_BUFFER, parm);
408 	if (rc) {
409 		char *err = "Unknown";
410 		switch (rc) {
411 		case 0x03:
412 			err = "Directory error";
413 			break;
414 		case 0x0a:
415 			err = "Invalid length";
416 			break;
417 		case 0x13:
418 			err = "Buffer already exists";
419 			break;
420 		case 0x3e:
421 			err = "Buffer overlap";
422 			break;
423 		case 0x5c:
424 			err = "Paging or storage error";
425 			break;
426 		}
427 		printk(KERN_WARNING "iucv_register: iucv_declare_buffer "
428 		       "on cpu %i returned error 0x%02x (%s)\n", cpu, rc, err);
429 		return;
430 	}
431 
432 	/* Set indication that an iucv buffer exists for this cpu. */
433 	cpu_set(cpu, iucv_buffer_cpumask);
434 
435 	if (iucv_nonsmp_handler == 0 || cpus_empty(iucv_irq_cpumask))
436 		/* Enable iucv interrupts on this cpu. */
437 		iucv_allow_cpu(NULL);
438 	else
439 		/* Disable iucv interrupts on this cpu. */
440 		iucv_block_cpu(NULL);
441 }
442 
443 /**
444  * iucv_retrieve_cpu
445  * @data: unused
446  *
447  * Retrieve interrupt buffer on this cpu.
448  */
449 static void iucv_retrieve_cpu(void *data)
450 {
451 	int cpu = smp_processor_id();
452 	union iucv_param *parm;
453 
454 	if (!cpu_isset(cpu, iucv_buffer_cpumask))
455 		return;
456 
457 	/* Block iucv interrupts. */
458 	iucv_block_cpu(NULL);
459 
460 	/* Retrieve interrupt buffer. */
461 	parm = percpu_ptr(iucv_param, cpu);
462 	iucv_call_b2f0(IUCV_RETRIEVE_BUFFER, parm);
463 
464 	/* Clear indication that an iucv buffer exists for this cpu. */
465 	cpu_clear(cpu, iucv_buffer_cpumask);
466 }
467 
468 /**
469  * iucv_setmask_smp
470  *
471  * Allow iucv interrupts on all cpus.
472  */
473 static void iucv_setmask_mp(void)
474 {
475 	int cpu;
476 
477 	preempt_disable();
478 	for_each_online_cpu(cpu)
479 		/* Enable all cpus with a declared buffer. */
480 		if (cpu_isset(cpu, iucv_buffer_cpumask) &&
481 		    !cpu_isset(cpu, iucv_irq_cpumask))
482 			smp_call_function_single(cpu, iucv_allow_cpu,
483 						 NULL, 0, 1);
484 	preempt_enable();
485 }
486 
487 /**
488  * iucv_setmask_up
489  *
490  * Allow iucv interrupts on a single cpu.
491  */
492 static void iucv_setmask_up(void)
493 {
494 	cpumask_t cpumask;
495 	int cpu;
496 
497 	/* Disable all cpu but the first in cpu_irq_cpumask. */
498 	cpumask = iucv_irq_cpumask;
499 	cpu_clear(first_cpu(iucv_irq_cpumask), cpumask);
500 	for_each_cpu_mask(cpu, cpumask)
501 		smp_call_function_single(cpu, iucv_block_cpu, NULL, 0, 1);
502 }
503 
504 /**
505  * iucv_enable
506  *
507  * This function makes iucv ready for use. It allocates the pathid
508  * table, declares an iucv interrupt buffer and enables the iucv
509  * interrupts. Called when the first user has registered an iucv
510  * handler.
511  */
512 static int iucv_enable(void)
513 {
514 	size_t alloc_size;
515 	int cpu, rc;
516 
517 	rc = -ENOMEM;
518 	alloc_size = iucv_max_pathid * sizeof(struct iucv_path);
519 	iucv_path_table = kzalloc(alloc_size, GFP_KERNEL);
520 	if (!iucv_path_table)
521 		goto out;
522 	/* Declare per cpu buffers. */
523 	rc = -EIO;
524 	preempt_disable();
525 	for_each_online_cpu(cpu)
526 		smp_call_function_single(cpu, iucv_declare_cpu, NULL, 0, 1);
527 	preempt_enable();
528 	if (cpus_empty(iucv_buffer_cpumask))
529 		/* No cpu could declare an iucv buffer. */
530 		goto out_path;
531 	return 0;
532 
533 out_path:
534 	kfree(iucv_path_table);
535 out:
536 	return rc;
537 }
538 
539 /**
540  * iucv_disable
541  *
542  * This function shuts down iucv. It disables iucv interrupts, retrieves
543  * the iucv interrupt buffer and frees the pathid table. Called after the
544  * last user unregister its iucv handler.
545  */
546 static void iucv_disable(void)
547 {
548 	on_each_cpu(iucv_retrieve_cpu, NULL, 0, 1);
549 	kfree(iucv_path_table);
550 }
551 
552 static int __cpuinit iucv_cpu_notify(struct notifier_block *self,
553 				     unsigned long action, void *hcpu)
554 {
555 	cpumask_t cpumask;
556 	long cpu = (long) hcpu;
557 
558 	switch (action) {
559 	case CPU_UP_PREPARE:
560 	case CPU_UP_PREPARE_FROZEN:
561 		if (!percpu_populate(iucv_irq_data,
562 				     sizeof(struct iucv_irq_data),
563 				     GFP_KERNEL|GFP_DMA, cpu))
564 			return NOTIFY_BAD;
565 		if (!percpu_populate(iucv_param, sizeof(union iucv_param),
566 				     GFP_KERNEL|GFP_DMA, cpu)) {
567 			percpu_depopulate(iucv_irq_data, cpu);
568 			return NOTIFY_BAD;
569 		}
570 		break;
571 	case CPU_UP_CANCELED:
572 	case CPU_UP_CANCELED_FROZEN:
573 	case CPU_DEAD:
574 	case CPU_DEAD_FROZEN:
575 		percpu_depopulate(iucv_param, cpu);
576 		percpu_depopulate(iucv_irq_data, cpu);
577 		break;
578 	case CPU_ONLINE:
579 	case CPU_ONLINE_FROZEN:
580 	case CPU_DOWN_FAILED:
581 	case CPU_DOWN_FAILED_FROZEN:
582 		smp_call_function_single(cpu, iucv_declare_cpu, NULL, 0, 1);
583 		break;
584 	case CPU_DOWN_PREPARE:
585 	case CPU_DOWN_PREPARE_FROZEN:
586 		cpumask = iucv_buffer_cpumask;
587 		cpu_clear(cpu, cpumask);
588 		if (cpus_empty(cpumask))
589 			/* Can't offline last IUCV enabled cpu. */
590 			return NOTIFY_BAD;
591 		smp_call_function_single(cpu, iucv_retrieve_cpu, NULL, 0, 1);
592 		if (cpus_empty(iucv_irq_cpumask))
593 			smp_call_function_single(first_cpu(iucv_buffer_cpumask),
594 						 iucv_allow_cpu, NULL, 0, 1);
595 		break;
596 	}
597 	return NOTIFY_OK;
598 }
599 
600 static struct notifier_block __cpuinitdata iucv_cpu_notifier = {
601 	.notifier_call = iucv_cpu_notify,
602 };
603 
604 /**
605  * iucv_sever_pathid
606  * @pathid: path identification number.
607  * @userdata: 16-bytes of user data.
608  *
609  * Sever an iucv path to free up the pathid. Used internally.
610  */
611 static int iucv_sever_pathid(u16 pathid, u8 userdata[16])
612 {
613 	union iucv_param *parm;
614 
615 	parm = percpu_ptr(iucv_param, smp_processor_id());
616 	memset(parm, 0, sizeof(union iucv_param));
617 	if (userdata)
618 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
619 	parm->ctrl.ippathid = pathid;
620 	return iucv_call_b2f0(IUCV_SEVER, parm);
621 }
622 
623 #ifdef CONFIG_SMP
624 /**
625  * __iucv_cleanup_queue
626  * @dummy: unused dummy argument
627  *
628  * Nop function called via smp_call_function to force work items from
629  * pending external iucv interrupts to the work queue.
630  */
631 static void __iucv_cleanup_queue(void *dummy)
632 {
633 }
634 #endif
635 
636 /**
637  * iucv_cleanup_queue
638  *
639  * Function called after a path has been severed to find all remaining
640  * work items for the now stale pathid. The caller needs to hold the
641  * iucv_table_lock.
642  */
643 static void iucv_cleanup_queue(void)
644 {
645 	struct iucv_irq_list *p, *n;
646 
647 	/*
648 	 * When a path is severed, the pathid can be reused immediatly
649 	 * on a iucv connect or a connection pending interrupt. Remove
650 	 * all entries from the task queue that refer to a stale pathid
651 	 * (iucv_path_table[ix] == NULL). Only then do the iucv connect
652 	 * or deliver the connection pending interrupt. To get all the
653 	 * pending interrupts force them to the work queue by calling
654 	 * an empty function on all cpus.
655 	 */
656 	smp_call_function(__iucv_cleanup_queue, NULL, 0, 1);
657 	spin_lock_irq(&iucv_queue_lock);
658 	list_for_each_entry_safe(p, n, &iucv_task_queue, list) {
659 		/* Remove stale work items from the task queue. */
660 		if (iucv_path_table[p->data.ippathid] == NULL) {
661 			list_del(&p->list);
662 			kfree(p);
663 		}
664 	}
665 	spin_unlock_irq(&iucv_queue_lock);
666 }
667 
668 /**
669  * iucv_register:
670  * @handler: address of iucv handler structure
671  * @smp: != 0 indicates that the handler can deal with out of order messages
672  *
673  * Registers a driver with IUCV.
674  *
675  * Returns 0 on success, -ENOMEM if the memory allocation for the pathid
676  * table failed, or -EIO if IUCV_DECLARE_BUFFER failed on all cpus.
677  */
678 int iucv_register(struct iucv_handler *handler, int smp)
679 {
680 	int rc;
681 
682 	if (!iucv_available)
683 		return -ENOSYS;
684 	mutex_lock(&iucv_register_mutex);
685 	if (!smp)
686 		iucv_nonsmp_handler++;
687 	if (list_empty(&iucv_handler_list)) {
688 		rc = iucv_enable();
689 		if (rc)
690 			goto out_mutex;
691 	} else if (!smp && iucv_nonsmp_handler == 1)
692 		iucv_setmask_up();
693 	INIT_LIST_HEAD(&handler->paths);
694 
695 	spin_lock_irq(&iucv_table_lock);
696 	list_add_tail(&handler->list, &iucv_handler_list);
697 	spin_unlock_irq(&iucv_table_lock);
698 	rc = 0;
699 out_mutex:
700 	mutex_unlock(&iucv_register_mutex);
701 	return rc;
702 }
703 EXPORT_SYMBOL(iucv_register);
704 
705 /**
706  * iucv_unregister
707  * @handler:  address of iucv handler structure
708  * @smp: != 0 indicates that the handler can deal with out of order messages
709  *
710  * Unregister driver from IUCV.
711  */
712 void iucv_unregister(struct iucv_handler *handler, int smp)
713 {
714 	struct iucv_path *p, *n;
715 
716 	mutex_lock(&iucv_register_mutex);
717 	spin_lock_bh(&iucv_table_lock);
718 	/* Remove handler from the iucv_handler_list. */
719 	list_del_init(&handler->list);
720 	/* Sever all pathids still refering to the handler. */
721 	list_for_each_entry_safe(p, n, &handler->paths, list) {
722 		iucv_sever_pathid(p->pathid, NULL);
723 		iucv_path_table[p->pathid] = NULL;
724 		list_del(&p->list);
725 		iucv_path_free(p);
726 	}
727 	spin_unlock_bh(&iucv_table_lock);
728 	if (!smp)
729 		iucv_nonsmp_handler--;
730 	if (list_empty(&iucv_handler_list))
731 		iucv_disable();
732 	else if (!smp && iucv_nonsmp_handler == 0)
733 		iucv_setmask_mp();
734 	mutex_unlock(&iucv_register_mutex);
735 }
736 EXPORT_SYMBOL(iucv_unregister);
737 
738 /**
739  * iucv_path_accept
740  * @path: address of iucv path structure
741  * @handler: address of iucv handler structure
742  * @userdata: 16 bytes of data reflected to the communication partner
743  * @private: private data passed to interrupt handlers for this path
744  *
745  * This function is issued after the user received a connection pending
746  * external interrupt and now wishes to complete the IUCV communication path.
747  *
748  * Returns the result of the CP IUCV call.
749  */
750 int iucv_path_accept(struct iucv_path *path, struct iucv_handler *handler,
751 		     u8 userdata[16], void *private)
752 {
753 	union iucv_param *parm;
754 	int rc;
755 
756 	local_bh_disable();
757 	/* Prepare parameter block. */
758 	parm = percpu_ptr(iucv_param, smp_processor_id());
759 	memset(parm, 0, sizeof(union iucv_param));
760 	parm->ctrl.ippathid = path->pathid;
761 	parm->ctrl.ipmsglim = path->msglim;
762 	if (userdata)
763 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
764 	parm->ctrl.ipflags1 = path->flags;
765 
766 	rc = iucv_call_b2f0(IUCV_ACCEPT, parm);
767 	if (!rc) {
768 		path->private = private;
769 		path->msglim = parm->ctrl.ipmsglim;
770 		path->flags = parm->ctrl.ipflags1;
771 	}
772 	local_bh_enable();
773 	return rc;
774 }
775 EXPORT_SYMBOL(iucv_path_accept);
776 
777 /**
778  * iucv_path_connect
779  * @path: address of iucv path structure
780  * @handler: address of iucv handler structure
781  * @userid: 8-byte user identification
782  * @system: 8-byte target system identification
783  * @userdata: 16 bytes of data reflected to the communication partner
784  * @private: private data passed to interrupt handlers for this path
785  *
786  * This function establishes an IUCV path. Although the connect may complete
787  * successfully, you are not able to use the path until you receive an IUCV
788  * Connection Complete external interrupt.
789  *
790  * Returns the result of the CP IUCV call.
791  */
792 int iucv_path_connect(struct iucv_path *path, struct iucv_handler *handler,
793 		      u8 userid[8], u8 system[8], u8 userdata[16],
794 		      void *private)
795 {
796 	union iucv_param *parm;
797 	int rc;
798 
799 	BUG_ON(in_atomic());
800 	spin_lock_bh(&iucv_table_lock);
801 	iucv_cleanup_queue();
802 	parm = percpu_ptr(iucv_param, smp_processor_id());
803 	memset(parm, 0, sizeof(union iucv_param));
804 	parm->ctrl.ipmsglim = path->msglim;
805 	parm->ctrl.ipflags1 = path->flags;
806 	if (userid) {
807 		memcpy(parm->ctrl.ipvmid, userid, sizeof(parm->ctrl.ipvmid));
808 		ASCEBC(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
809 		EBC_TOUPPER(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
810 	}
811 	if (system) {
812 		memcpy(parm->ctrl.iptarget, system,
813 		       sizeof(parm->ctrl.iptarget));
814 		ASCEBC(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
815 		EBC_TOUPPER(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
816 	}
817 	if (userdata)
818 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
819 
820 	rc = iucv_call_b2f0(IUCV_CONNECT, parm);
821 	if (!rc) {
822 		if (parm->ctrl.ippathid < iucv_max_pathid) {
823 			path->pathid = parm->ctrl.ippathid;
824 			path->msglim = parm->ctrl.ipmsglim;
825 			path->flags = parm->ctrl.ipflags1;
826 			path->handler = handler;
827 			path->private = private;
828 			list_add_tail(&path->list, &handler->paths);
829 			iucv_path_table[path->pathid] = path;
830 		} else {
831 			iucv_sever_pathid(parm->ctrl.ippathid,
832 					  iucv_error_pathid);
833 			rc = -EIO;
834 		}
835 	}
836 	spin_unlock_bh(&iucv_table_lock);
837 	return rc;
838 }
839 EXPORT_SYMBOL(iucv_path_connect);
840 
841 /**
842  * iucv_path_quiesce:
843  * @path: address of iucv path structure
844  * @userdata: 16 bytes of data reflected to the communication partner
845  *
846  * This function temporarily suspends incoming messages on an IUCV path.
847  * You can later reactivate the path by invoking the iucv_resume function.
848  *
849  * Returns the result from the CP IUCV call.
850  */
851 int iucv_path_quiesce(struct iucv_path *path, u8 userdata[16])
852 {
853 	union iucv_param *parm;
854 	int rc;
855 
856 	local_bh_disable();
857 	parm = percpu_ptr(iucv_param, smp_processor_id());
858 	memset(parm, 0, sizeof(union iucv_param));
859 	if (userdata)
860 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
861 	parm->ctrl.ippathid = path->pathid;
862 	rc = iucv_call_b2f0(IUCV_QUIESCE, parm);
863 	local_bh_enable();
864 	return rc;
865 }
866 EXPORT_SYMBOL(iucv_path_quiesce);
867 
868 /**
869  * iucv_path_resume:
870  * @path: address of iucv path structure
871  * @userdata: 16 bytes of data reflected to the communication partner
872  *
873  * This function resumes incoming messages on an IUCV path that has
874  * been stopped with iucv_path_quiesce.
875  *
876  * Returns the result from the CP IUCV call.
877  */
878 int iucv_path_resume(struct iucv_path *path, u8 userdata[16])
879 {
880 	union iucv_param *parm;
881 	int rc;
882 
883 	local_bh_disable();
884 	parm = percpu_ptr(iucv_param, smp_processor_id());
885 	memset(parm, 0, sizeof(union iucv_param));
886 	if (userdata)
887 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
888 	parm->ctrl.ippathid = path->pathid;
889 	rc = iucv_call_b2f0(IUCV_RESUME, parm);
890 	local_bh_enable();
891 	return rc;
892 }
893 
894 /**
895  * iucv_path_sever
896  * @path: address of iucv path structure
897  * @userdata: 16 bytes of data reflected to the communication partner
898  *
899  * This function terminates an IUCV path.
900  *
901  * Returns the result from the CP IUCV call.
902  */
903 int iucv_path_sever(struct iucv_path *path, u8 userdata[16])
904 {
905 	int rc;
906 
907 	preempt_disable();
908 	if (iucv_active_cpu != smp_processor_id())
909 		spin_lock_bh(&iucv_table_lock);
910 	rc = iucv_sever_pathid(path->pathid, userdata);
911 	if (!rc) {
912 		iucv_path_table[path->pathid] = NULL;
913 		list_del_init(&path->list);
914 	}
915 	if (iucv_active_cpu != smp_processor_id())
916 		spin_unlock_bh(&iucv_table_lock);
917 	preempt_enable();
918 	return rc;
919 }
920 EXPORT_SYMBOL(iucv_path_sever);
921 
922 /**
923  * iucv_message_purge
924  * @path: address of iucv path structure
925  * @msg: address of iucv msg structure
926  * @srccls: source class of message
927  *
928  * Cancels a message you have sent.
929  *
930  * Returns the result from the CP IUCV call.
931  */
932 int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg,
933 		       u32 srccls)
934 {
935 	union iucv_param *parm;
936 	int rc;
937 
938 	local_bh_disable();
939 	parm = percpu_ptr(iucv_param, smp_processor_id());
940 	memset(parm, 0, sizeof(union iucv_param));
941 	parm->purge.ippathid = path->pathid;
942 	parm->purge.ipmsgid = msg->id;
943 	parm->purge.ipsrccls = srccls;
944 	parm->purge.ipflags1 = IUCV_IPSRCCLS | IUCV_IPFGMID | IUCV_IPFGPID;
945 	rc = iucv_call_b2f0(IUCV_PURGE, parm);
946 	if (!rc) {
947 		msg->audit = (*(u32 *) &parm->purge.ipaudit) >> 8;
948 		msg->tag = parm->purge.ipmsgtag;
949 	}
950 	local_bh_enable();
951 	return rc;
952 }
953 EXPORT_SYMBOL(iucv_message_purge);
954 
955 /**
956  * iucv_message_receive
957  * @path: address of iucv path structure
958  * @msg: address of iucv msg structure
959  * @flags: how the message is received (IUCV_IPBUFLST)
960  * @buffer: address of data buffer or address of struct iucv_array
961  * @size: length of data buffer
962  * @residual:
963  *
964  * This function receives messages that are being sent to you over
965  * established paths. This function will deal with RMDATA messages
966  * embedded in struct iucv_message as well.
967  *
968  * Returns the result from the CP IUCV call.
969  */
970 int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
971 			 u8 flags, void *buffer, size_t size, size_t *residual)
972 {
973 	union iucv_param *parm;
974 	struct iucv_array *array;
975 	u8 *rmmsg;
976 	size_t copy;
977 	int rc;
978 
979 	if (msg->flags & IUCV_IPRMDATA) {
980 		/*
981 		 * Message is 8 bytes long and has been stored to the
982 		 * message descriptor itself.
983 		 */
984 		rc = (size < 8) ? 5 : 0;
985 		if (residual)
986 			*residual = abs(size - 8);
987 		rmmsg = msg->rmmsg;
988 		if (flags & IUCV_IPBUFLST) {
989 			/* Copy to struct iucv_array. */
990 			size = (size < 8) ? size : 8;
991 			for (array = buffer; size > 0; array++) {
992 				copy = min_t(size_t, size, array->length);
993 				memcpy((u8 *)(addr_t) array->address,
994 				       rmmsg, copy);
995 				rmmsg += copy;
996 				size -= copy;
997 			}
998 		} else {
999 			/* Copy to direct buffer. */
1000 			memcpy(buffer, rmmsg, min_t(size_t, size, 8));
1001 		}
1002 		return 0;
1003 	}
1004 
1005 	local_bh_disable();
1006 	parm = percpu_ptr(iucv_param, smp_processor_id());
1007 	memset(parm, 0, sizeof(union iucv_param));
1008 	parm->db.ipbfadr1 = (u32)(addr_t) buffer;
1009 	parm->db.ipbfln1f = (u32) size;
1010 	parm->db.ipmsgid = msg->id;
1011 	parm->db.ippathid = path->pathid;
1012 	parm->db.iptrgcls = msg->class;
1013 	parm->db.ipflags1 = (flags | IUCV_IPFGPID |
1014 			     IUCV_IPFGMID | IUCV_IPTRGCLS);
1015 	rc = iucv_call_b2f0(IUCV_RECEIVE, parm);
1016 	if (!rc || rc == 5) {
1017 		msg->flags = parm->db.ipflags1;
1018 		if (residual)
1019 			*residual = parm->db.ipbfln1f;
1020 	}
1021 	local_bh_enable();
1022 	return rc;
1023 }
1024 EXPORT_SYMBOL(iucv_message_receive);
1025 
1026 /**
1027  * iucv_message_reject
1028  * @path: address of iucv path structure
1029  * @msg: address of iucv msg structure
1030  *
1031  * The reject function refuses a specified message. Between the time you
1032  * are notified of a message and the time that you complete the message,
1033  * the message may be rejected.
1034  *
1035  * Returns the result from the CP IUCV call.
1036  */
1037 int iucv_message_reject(struct iucv_path *path, struct iucv_message *msg)
1038 {
1039 	union iucv_param *parm;
1040 	int rc;
1041 
1042 	local_bh_disable();
1043 	parm = percpu_ptr(iucv_param, smp_processor_id());
1044 	memset(parm, 0, sizeof(union iucv_param));
1045 	parm->db.ippathid = path->pathid;
1046 	parm->db.ipmsgid = msg->id;
1047 	parm->db.iptrgcls = msg->class;
1048 	parm->db.ipflags1 = (IUCV_IPTRGCLS | IUCV_IPFGMID | IUCV_IPFGPID);
1049 	rc = iucv_call_b2f0(IUCV_REJECT, parm);
1050 	local_bh_enable();
1051 	return rc;
1052 }
1053 EXPORT_SYMBOL(iucv_message_reject);
1054 
1055 /**
1056  * iucv_message_reply
1057  * @path: address of iucv path structure
1058  * @msg: address of iucv msg structure
1059  * @flags: how the reply is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1060  * @reply: address of reply data buffer or address of struct iucv_array
1061  * @size: length of reply data buffer
1062  *
1063  * This function responds to the two-way messages that you receive. You
1064  * must identify completely the message to which you wish to reply. ie,
1065  * pathid, msgid, and trgcls. Prmmsg signifies the data is moved into
1066  * the parameter list.
1067  *
1068  * Returns the result from the CP IUCV call.
1069  */
1070 int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg,
1071 		       u8 flags, void *reply, size_t size)
1072 {
1073 	union iucv_param *parm;
1074 	int rc;
1075 
1076 	local_bh_disable();
1077 	parm = percpu_ptr(iucv_param, smp_processor_id());
1078 	memset(parm, 0, sizeof(union iucv_param));
1079 	if (flags & IUCV_IPRMDATA) {
1080 		parm->dpl.ippathid = path->pathid;
1081 		parm->dpl.ipflags1 = flags;
1082 		parm->dpl.ipmsgid = msg->id;
1083 		parm->dpl.iptrgcls = msg->class;
1084 		memcpy(parm->dpl.iprmmsg, reply, min_t(size_t, size, 8));
1085 	} else {
1086 		parm->db.ipbfadr1 = (u32)(addr_t) reply;
1087 		parm->db.ipbfln1f = (u32) size;
1088 		parm->db.ippathid = path->pathid;
1089 		parm->db.ipflags1 = flags;
1090 		parm->db.ipmsgid = msg->id;
1091 		parm->db.iptrgcls = msg->class;
1092 	}
1093 	rc = iucv_call_b2f0(IUCV_REPLY, parm);
1094 	local_bh_enable();
1095 	return rc;
1096 }
1097 EXPORT_SYMBOL(iucv_message_reply);
1098 
1099 /**
1100  * iucv_message_send
1101  * @path: address of iucv path structure
1102  * @msg: address of iucv msg structure
1103  * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1104  * @srccls: source class of message
1105  * @buffer: address of send buffer or address of struct iucv_array
1106  * @size: length of send buffer
1107  *
1108  * This function transmits data to another application. Data to be
1109  * transmitted is in a buffer and this is a one-way message and the
1110  * receiver will not reply to the message.
1111  *
1112  * Returns the result from the CP IUCV call.
1113  */
1114 int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
1115 		      u8 flags, u32 srccls, void *buffer, size_t size)
1116 {
1117 	union iucv_param *parm;
1118 	int rc;
1119 
1120 	local_bh_disable();
1121 	parm = percpu_ptr(iucv_param, smp_processor_id());
1122 	memset(parm, 0, sizeof(union iucv_param));
1123 	if (flags & IUCV_IPRMDATA) {
1124 		/* Message of 8 bytes can be placed into the parameter list. */
1125 		parm->dpl.ippathid = path->pathid;
1126 		parm->dpl.ipflags1 = flags | IUCV_IPNORPY;
1127 		parm->dpl.iptrgcls = msg->class;
1128 		parm->dpl.ipsrccls = srccls;
1129 		parm->dpl.ipmsgtag = msg->tag;
1130 		memcpy(parm->dpl.iprmmsg, buffer, 8);
1131 	} else {
1132 		parm->db.ipbfadr1 = (u32)(addr_t) buffer;
1133 		parm->db.ipbfln1f = (u32) size;
1134 		parm->db.ippathid = path->pathid;
1135 		parm->db.ipflags1 = flags | IUCV_IPNORPY;
1136 		parm->db.iptrgcls = msg->class;
1137 		parm->db.ipsrccls = srccls;
1138 		parm->db.ipmsgtag = msg->tag;
1139 	}
1140 	rc = iucv_call_b2f0(IUCV_SEND, parm);
1141 	if (!rc)
1142 		msg->id = parm->db.ipmsgid;
1143 	local_bh_enable();
1144 	return rc;
1145 }
1146 EXPORT_SYMBOL(iucv_message_send);
1147 
1148 /**
1149  * iucv_message_send2way
1150  * @path: address of iucv path structure
1151  * @msg: address of iucv msg structure
1152  * @flags: how the message is sent and the reply is received
1153  *	   (IUCV_IPRMDATA, IUCV_IPBUFLST, IUCV_IPPRTY, IUCV_ANSLST)
1154  * @srccls: source class of message
1155  * @buffer: address of send buffer or address of struct iucv_array
1156  * @size: length of send buffer
1157  * @ansbuf: address of answer buffer or address of struct iucv_array
1158  * @asize: size of reply buffer
1159  *
1160  * This function transmits data to another application. Data to be
1161  * transmitted is in a buffer. The receiver of the send is expected to
1162  * reply to the message and a buffer is provided into which IUCV moves
1163  * the reply to this message.
1164  *
1165  * Returns the result from the CP IUCV call.
1166  */
1167 int iucv_message_send2way(struct iucv_path *path, struct iucv_message *msg,
1168 			  u8 flags, u32 srccls, void *buffer, size_t size,
1169 			  void *answer, size_t asize, size_t *residual)
1170 {
1171 	union iucv_param *parm;
1172 	int rc;
1173 
1174 	local_bh_disable();
1175 	parm = percpu_ptr(iucv_param, smp_processor_id());
1176 	memset(parm, 0, sizeof(union iucv_param));
1177 	if (flags & IUCV_IPRMDATA) {
1178 		parm->dpl.ippathid = path->pathid;
1179 		parm->dpl.ipflags1 = path->flags;	/* priority message */
1180 		parm->dpl.iptrgcls = msg->class;
1181 		parm->dpl.ipsrccls = srccls;
1182 		parm->dpl.ipmsgtag = msg->tag;
1183 		parm->dpl.ipbfadr2 = (u32)(addr_t) answer;
1184 		parm->dpl.ipbfln2f = (u32) asize;
1185 		memcpy(parm->dpl.iprmmsg, buffer, 8);
1186 	} else {
1187 		parm->db.ippathid = path->pathid;
1188 		parm->db.ipflags1 = path->flags;	/* priority message */
1189 		parm->db.iptrgcls = msg->class;
1190 		parm->db.ipsrccls = srccls;
1191 		parm->db.ipmsgtag = msg->tag;
1192 		parm->db.ipbfadr1 = (u32)(addr_t) buffer;
1193 		parm->db.ipbfln1f = (u32) size;
1194 		parm->db.ipbfadr2 = (u32)(addr_t) answer;
1195 		parm->db.ipbfln2f = (u32) asize;
1196 	}
1197 	rc = iucv_call_b2f0(IUCV_SEND, parm);
1198 	if (!rc)
1199 		msg->id = parm->db.ipmsgid;
1200 	local_bh_enable();
1201 	return rc;
1202 }
1203 EXPORT_SYMBOL(iucv_message_send2way);
1204 
1205 /**
1206  * iucv_path_pending
1207  * @data: Pointer to external interrupt buffer
1208  *
1209  * Process connection pending work item. Called from tasklet while holding
1210  * iucv_table_lock.
1211  */
1212 struct iucv_path_pending {
1213 	u16 ippathid;
1214 	u8  ipflags1;
1215 	u8  iptype;
1216 	u16 ipmsglim;
1217 	u16 res1;
1218 	u8  ipvmid[8];
1219 	u8  ipuser[16];
1220 	u32 res3;
1221 	u8  ippollfg;
1222 	u8  res4[3];
1223 } __attribute__ ((packed));
1224 
1225 static void iucv_path_pending(struct iucv_irq_data *data)
1226 {
1227 	struct iucv_path_pending *ipp = (void *) data;
1228 	struct iucv_handler *handler;
1229 	struct iucv_path *path;
1230 	char *error;
1231 
1232 	BUG_ON(iucv_path_table[ipp->ippathid]);
1233 	/* New pathid, handler found. Create a new path struct. */
1234 	error = iucv_error_no_memory;
1235 	path = iucv_path_alloc(ipp->ipmsglim, ipp->ipflags1, GFP_ATOMIC);
1236 	if (!path)
1237 		goto out_sever;
1238 	path->pathid = ipp->ippathid;
1239 	iucv_path_table[path->pathid] = path;
1240 	EBCASC(ipp->ipvmid, 8);
1241 
1242 	/* Call registered handler until one is found that wants the path. */
1243 	list_for_each_entry(handler, &iucv_handler_list, list) {
1244 		if (!handler->path_pending)
1245 			continue;
1246 		/*
1247 		 * Add path to handler to allow a call to iucv_path_sever
1248 		 * inside the path_pending function. If the handler returns
1249 		 * an error remove the path from the handler again.
1250 		 */
1251 		list_add(&path->list, &handler->paths);
1252 		path->handler = handler;
1253 		if (!handler->path_pending(path, ipp->ipvmid, ipp->ipuser))
1254 			return;
1255 		list_del(&path->list);
1256 		path->handler = NULL;
1257 	}
1258 	/* No handler wanted the path. */
1259 	iucv_path_table[path->pathid] = NULL;
1260 	iucv_path_free(path);
1261 	error = iucv_error_no_listener;
1262 out_sever:
1263 	iucv_sever_pathid(ipp->ippathid, error);
1264 }
1265 
1266 /**
1267  * iucv_path_complete
1268  * @data: Pointer to external interrupt buffer
1269  *
1270  * Process connection complete work item. Called from tasklet while holding
1271  * iucv_table_lock.
1272  */
1273 struct iucv_path_complete {
1274 	u16 ippathid;
1275 	u8  ipflags1;
1276 	u8  iptype;
1277 	u16 ipmsglim;
1278 	u16 res1;
1279 	u8  res2[8];
1280 	u8  ipuser[16];
1281 	u32 res3;
1282 	u8  ippollfg;
1283 	u8  res4[3];
1284 } __attribute__ ((packed));
1285 
1286 static void iucv_path_complete(struct iucv_irq_data *data)
1287 {
1288 	struct iucv_path_complete *ipc = (void *) data;
1289 	struct iucv_path *path = iucv_path_table[ipc->ippathid];
1290 
1291 	if (path && path->handler && path->handler->path_complete)
1292 		path->handler->path_complete(path, ipc->ipuser);
1293 }
1294 
1295 /**
1296  * iucv_path_severed
1297  * @data: Pointer to external interrupt buffer
1298  *
1299  * Process connection severed work item. Called from tasklet while holding
1300  * iucv_table_lock.
1301  */
1302 struct iucv_path_severed {
1303 	u16 ippathid;
1304 	u8  res1;
1305 	u8  iptype;
1306 	u32 res2;
1307 	u8  res3[8];
1308 	u8  ipuser[16];
1309 	u32 res4;
1310 	u8  ippollfg;
1311 	u8  res5[3];
1312 } __attribute__ ((packed));
1313 
1314 static void iucv_path_severed(struct iucv_irq_data *data)
1315 {
1316 	struct iucv_path_severed *ips = (void *) data;
1317 	struct iucv_path *path = iucv_path_table[ips->ippathid];
1318 
1319 	if (!path || !path->handler)	/* Already severed */
1320 		return;
1321 	if (path->handler->path_severed)
1322 		path->handler->path_severed(path, ips->ipuser);
1323 	else {
1324 		iucv_sever_pathid(path->pathid, NULL);
1325 		iucv_path_table[path->pathid] = NULL;
1326 		list_del_init(&path->list);
1327 		iucv_path_free(path);
1328 	}
1329 }
1330 
1331 /**
1332  * iucv_path_quiesced
1333  * @data: Pointer to external interrupt buffer
1334  *
1335  * Process connection quiesced work item. Called from tasklet while holding
1336  * iucv_table_lock.
1337  */
1338 struct iucv_path_quiesced {
1339 	u16 ippathid;
1340 	u8  res1;
1341 	u8  iptype;
1342 	u32 res2;
1343 	u8  res3[8];
1344 	u8  ipuser[16];
1345 	u32 res4;
1346 	u8  ippollfg;
1347 	u8  res5[3];
1348 } __attribute__ ((packed));
1349 
1350 static void iucv_path_quiesced(struct iucv_irq_data *data)
1351 {
1352 	struct iucv_path_quiesced *ipq = (void *) data;
1353 	struct iucv_path *path = iucv_path_table[ipq->ippathid];
1354 
1355 	if (path && path->handler && path->handler->path_quiesced)
1356 		path->handler->path_quiesced(path, ipq->ipuser);
1357 }
1358 
1359 /**
1360  * iucv_path_resumed
1361  * @data: Pointer to external interrupt buffer
1362  *
1363  * Process connection resumed work item. Called from tasklet while holding
1364  * iucv_table_lock.
1365  */
1366 struct iucv_path_resumed {
1367 	u16 ippathid;
1368 	u8  res1;
1369 	u8  iptype;
1370 	u32 res2;
1371 	u8  res3[8];
1372 	u8  ipuser[16];
1373 	u32 res4;
1374 	u8  ippollfg;
1375 	u8  res5[3];
1376 } __attribute__ ((packed));
1377 
1378 static void iucv_path_resumed(struct iucv_irq_data *data)
1379 {
1380 	struct iucv_path_resumed *ipr = (void *) data;
1381 	struct iucv_path *path = iucv_path_table[ipr->ippathid];
1382 
1383 	if (path && path->handler && path->handler->path_resumed)
1384 		path->handler->path_resumed(path, ipr->ipuser);
1385 }
1386 
1387 /**
1388  * iucv_message_complete
1389  * @data: Pointer to external interrupt buffer
1390  *
1391  * Process message complete work item. Called from tasklet while holding
1392  * iucv_table_lock.
1393  */
1394 struct iucv_message_complete {
1395 	u16 ippathid;
1396 	u8  ipflags1;
1397 	u8  iptype;
1398 	u32 ipmsgid;
1399 	u32 ipaudit;
1400 	u8  iprmmsg[8];
1401 	u32 ipsrccls;
1402 	u32 ipmsgtag;
1403 	u32 res;
1404 	u32 ipbfln2f;
1405 	u8  ippollfg;
1406 	u8  res2[3];
1407 } __attribute__ ((packed));
1408 
1409 static void iucv_message_complete(struct iucv_irq_data *data)
1410 {
1411 	struct iucv_message_complete *imc = (void *) data;
1412 	struct iucv_path *path = iucv_path_table[imc->ippathid];
1413 	struct iucv_message msg;
1414 
1415 	if (path && path->handler && path->handler->message_complete) {
1416 		msg.flags = imc->ipflags1;
1417 		msg.id = imc->ipmsgid;
1418 		msg.audit = imc->ipaudit;
1419 		memcpy(msg.rmmsg, imc->iprmmsg, 8);
1420 		msg.class = imc->ipsrccls;
1421 		msg.tag = imc->ipmsgtag;
1422 		msg.length = imc->ipbfln2f;
1423 		path->handler->message_complete(path, &msg);
1424 	}
1425 }
1426 
1427 /**
1428  * iucv_message_pending
1429  * @data: Pointer to external interrupt buffer
1430  *
1431  * Process message pending work item. Called from tasklet while holding
1432  * iucv_table_lock.
1433  */
1434 struct iucv_message_pending {
1435 	u16 ippathid;
1436 	u8  ipflags1;
1437 	u8  iptype;
1438 	u32 ipmsgid;
1439 	u32 iptrgcls;
1440 	union {
1441 		u32 iprmmsg1_u32;
1442 		u8  iprmmsg1[4];
1443 	} ln1msg1;
1444 	union {
1445 		u32 ipbfln1f;
1446 		u8  iprmmsg2[4];
1447 	} ln1msg2;
1448 	u32 res1[3];
1449 	u32 ipbfln2f;
1450 	u8  ippollfg;
1451 	u8  res2[3];
1452 } __attribute__ ((packed));
1453 
1454 static void iucv_message_pending(struct iucv_irq_data *data)
1455 {
1456 	struct iucv_message_pending *imp = (void *) data;
1457 	struct iucv_path *path = iucv_path_table[imp->ippathid];
1458 	struct iucv_message msg;
1459 
1460 	if (path && path->handler && path->handler->message_pending) {
1461 		msg.flags = imp->ipflags1;
1462 		msg.id = imp->ipmsgid;
1463 		msg.class = imp->iptrgcls;
1464 		if (imp->ipflags1 & IUCV_IPRMDATA) {
1465 			memcpy(msg.rmmsg, imp->ln1msg1.iprmmsg1, 8);
1466 			msg.length = 8;
1467 		} else
1468 			msg.length = imp->ln1msg2.ipbfln1f;
1469 		msg.reply_size = imp->ipbfln2f;
1470 		path->handler->message_pending(path, &msg);
1471 	}
1472 }
1473 
1474 /**
1475  * iucv_tasklet_fn:
1476  *
1477  * This tasklet loops over the queue of irq buffers created by
1478  * iucv_external_interrupt, calls the appropriate action handler
1479  * and then frees the buffer.
1480  */
1481 static void iucv_tasklet_fn(unsigned long ignored)
1482 {
1483 	typedef void iucv_irq_fn(struct iucv_irq_data *);
1484 	static iucv_irq_fn *irq_fn[] = {
1485 		[0x02] = iucv_path_complete,
1486 		[0x03] = iucv_path_severed,
1487 		[0x04] = iucv_path_quiesced,
1488 		[0x05] = iucv_path_resumed,
1489 		[0x06] = iucv_message_complete,
1490 		[0x07] = iucv_message_complete,
1491 		[0x08] = iucv_message_pending,
1492 		[0x09] = iucv_message_pending,
1493 	};
1494 	struct list_head task_queue = LIST_HEAD_INIT(task_queue);
1495 	struct iucv_irq_list *p, *n;
1496 
1497 	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */
1498 	if (!spin_trylock(&iucv_table_lock)) {
1499 		tasklet_schedule(&iucv_tasklet);
1500 		return;
1501 	}
1502 	iucv_active_cpu = smp_processor_id();
1503 
1504 	spin_lock_irq(&iucv_queue_lock);
1505 	list_splice_init(&iucv_task_queue, &task_queue);
1506 	spin_unlock_irq(&iucv_queue_lock);
1507 
1508 	list_for_each_entry_safe(p, n, &task_queue, list) {
1509 		list_del_init(&p->list);
1510 		irq_fn[p->data.iptype](&p->data);
1511 		kfree(p);
1512 	}
1513 
1514 	iucv_active_cpu = -1;
1515 	spin_unlock(&iucv_table_lock);
1516 }
1517 
1518 /**
1519  * iucv_work_fn:
1520  *
1521  * This work function loops over the queue of path pending irq blocks
1522  * created by iucv_external_interrupt, calls the appropriate action
1523  * handler and then frees the buffer.
1524  */
1525 static void iucv_work_fn(struct work_struct *work)
1526 {
1527 	typedef void iucv_irq_fn(struct iucv_irq_data *);
1528 	struct list_head work_queue = LIST_HEAD_INIT(work_queue);
1529 	struct iucv_irq_list *p, *n;
1530 
1531 	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */
1532 	spin_lock_bh(&iucv_table_lock);
1533 	iucv_active_cpu = smp_processor_id();
1534 
1535 	spin_lock_irq(&iucv_queue_lock);
1536 	list_splice_init(&iucv_work_queue, &work_queue);
1537 	spin_unlock_irq(&iucv_queue_lock);
1538 
1539 	iucv_cleanup_queue();
1540 	list_for_each_entry_safe(p, n, &work_queue, list) {
1541 		list_del_init(&p->list);
1542 		iucv_path_pending(&p->data);
1543 		kfree(p);
1544 	}
1545 
1546 	iucv_active_cpu = -1;
1547 	spin_unlock_bh(&iucv_table_lock);
1548 }
1549 
1550 /**
1551  * iucv_external_interrupt
1552  * @code: irq code
1553  *
1554  * Handles external interrupts coming in from CP.
1555  * Places the interrupt buffer on a queue and schedules iucv_tasklet_fn().
1556  */
1557 static void iucv_external_interrupt(u16 code)
1558 {
1559 	struct iucv_irq_data *p;
1560 	struct iucv_irq_list *work;
1561 
1562 	p = percpu_ptr(iucv_irq_data, smp_processor_id());
1563 	if (p->ippathid >= iucv_max_pathid) {
1564 		printk(KERN_WARNING "iucv_do_int: Got interrupt with "
1565 		       "pathid %d > max_connections (%ld)\n",
1566 		       p->ippathid, iucv_max_pathid - 1);
1567 		iucv_sever_pathid(p->ippathid, iucv_error_no_listener);
1568 		return;
1569 	}
1570 	if (p->iptype  < 0x01 || p->iptype > 0x09) {
1571 		printk(KERN_ERR "iucv_do_int: unknown iucv interrupt\n");
1572 		return;
1573 	}
1574 	work = kmalloc(sizeof(struct iucv_irq_list), GFP_ATOMIC);
1575 	if (!work) {
1576 		printk(KERN_WARNING "iucv_external_interrupt: out of memory\n");
1577 		return;
1578 	}
1579 	memcpy(&work->data, p, sizeof(work->data));
1580 	spin_lock(&iucv_queue_lock);
1581 	if (p->iptype == 0x01) {
1582 		/* Path pending interrupt. */
1583 		list_add_tail(&work->list, &iucv_work_queue);
1584 		schedule_work(&iucv_work);
1585 	} else {
1586 		/* The other interrupts. */
1587 		list_add_tail(&work->list, &iucv_task_queue);
1588 		tasklet_schedule(&iucv_tasklet);
1589 	}
1590 	spin_unlock(&iucv_queue_lock);
1591 }
1592 
1593 /**
1594  * iucv_init
1595  *
1596  * Allocates and initializes various data structures.
1597  */
1598 static int __init iucv_init(void)
1599 {
1600 	int rc;
1601 
1602 	if (!MACHINE_IS_VM) {
1603 		rc = -EPROTONOSUPPORT;
1604 		goto out;
1605 	}
1606 	rc = iucv_query_maxconn();
1607 	if (rc)
1608 		goto out;
1609 	rc = register_external_interrupt(0x4000, iucv_external_interrupt);
1610 	if (rc)
1611 		goto out;
1612 	rc = bus_register(&iucv_bus);
1613 	if (rc)
1614 		goto out_int;
1615 	iucv_root = s390_root_dev_register("iucv");
1616 	if (IS_ERR(iucv_root)) {
1617 		rc = PTR_ERR(iucv_root);
1618 		goto out_bus;
1619 	}
1620 	/* Note: GFP_DMA used to get memory below 2G */
1621 	iucv_irq_data = percpu_alloc(sizeof(struct iucv_irq_data),
1622 				     GFP_KERNEL|GFP_DMA);
1623 	if (!iucv_irq_data) {
1624 		rc = -ENOMEM;
1625 		goto out_root;
1626 	}
1627 	/* Allocate parameter blocks. */
1628 	iucv_param = percpu_alloc(sizeof(union iucv_param),
1629 				  GFP_KERNEL|GFP_DMA);
1630 	if (!iucv_param) {
1631 		rc = -ENOMEM;
1632 		goto out_extint;
1633 	}
1634 	register_hotcpu_notifier(&iucv_cpu_notifier);
1635 	ASCEBC(iucv_error_no_listener, 16);
1636 	ASCEBC(iucv_error_no_memory, 16);
1637 	ASCEBC(iucv_error_pathid, 16);
1638 	iucv_available = 1;
1639 	return 0;
1640 
1641 out_extint:
1642 	percpu_free(iucv_irq_data);
1643 out_root:
1644 	s390_root_dev_unregister(iucv_root);
1645 out_bus:
1646 	bus_unregister(&iucv_bus);
1647 out_int:
1648 	unregister_external_interrupt(0x4000, iucv_external_interrupt);
1649 out:
1650 	return rc;
1651 }
1652 
1653 /**
1654  * iucv_exit
1655  *
1656  * Frees everything allocated from iucv_init.
1657  */
1658 static void __exit iucv_exit(void)
1659 {
1660 	struct iucv_irq_list *p, *n;
1661 
1662 	spin_lock_irq(&iucv_queue_lock);
1663 	list_for_each_entry_safe(p, n, &iucv_task_queue, list)
1664 		kfree(p);
1665 	list_for_each_entry_safe(p, n, &iucv_work_queue, list)
1666 		kfree(p);
1667 	spin_unlock_irq(&iucv_queue_lock);
1668 	unregister_hotcpu_notifier(&iucv_cpu_notifier);
1669 	percpu_free(iucv_param);
1670 	percpu_free(iucv_irq_data);
1671 	s390_root_dev_unregister(iucv_root);
1672 	bus_unregister(&iucv_bus);
1673 	unregister_external_interrupt(0x4000, iucv_external_interrupt);
1674 }
1675 
1676 subsys_initcall(iucv_init);
1677 module_exit(iucv_exit);
1678 
1679 MODULE_AUTHOR("(C) 2001 IBM Corp. by Fritz Elfert (felfert@millenux.com)");
1680 MODULE_DESCRIPTION("Linux for S/390 IUCV lowlevel driver");
1681 MODULE_LICENSE("GPL");
1682