xref: /openbmc/linux/net/iucv/iucv.c (revision 545e4006)
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[NR_CPUS];
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[NR_CPUS];
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 = iucv_param[cpu];
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 = iucv_param[cpu];
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 = iucv_param[cpu];
405 	memset(parm, 0, sizeof(union iucv_param));
406 	parm->db.ipbfadr1 = virt_to_phys(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 = 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 	get_online_cpus();
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, 1);
484 	put_online_cpus();
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_nr(cpu, cpumask)
501 		smp_call_function_single(cpu, iucv_block_cpu, NULL, 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 	get_online_cpus();
525 	for_each_online_cpu(cpu)
526 		smp_call_function_single(cpu, iucv_declare_cpu, NULL, 1);
527 	preempt_enable();
528 	if (cpus_empty(iucv_buffer_cpumask))
529 		/* No cpu could declare an iucv buffer. */
530 		goto out_path;
531 	put_online_cpus();
532 	return 0;
533 
534 out_path:
535 	put_online_cpus();
536 	kfree(iucv_path_table);
537 out:
538 	return rc;
539 }
540 
541 /**
542  * iucv_disable
543  *
544  * This function shuts down iucv. It disables iucv interrupts, retrieves
545  * the iucv interrupt buffer and frees the pathid table. Called after the
546  * last user unregister its iucv handler.
547  */
548 static void iucv_disable(void)
549 {
550 	on_each_cpu(iucv_retrieve_cpu, NULL, 1);
551 	kfree(iucv_path_table);
552 }
553 
554 static int __cpuinit iucv_cpu_notify(struct notifier_block *self,
555 				     unsigned long action, void *hcpu)
556 {
557 	cpumask_t cpumask;
558 	long cpu = (long) hcpu;
559 
560 	switch (action) {
561 	case CPU_UP_PREPARE:
562 	case CPU_UP_PREPARE_FROZEN:
563 		iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
564 					GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
565 		if (!iucv_irq_data[cpu])
566 			return NOTIFY_BAD;
567 		iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
568 				     GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
569 		if (!iucv_param[cpu]) {
570 			kfree(iucv_irq_data[cpu]);
571 			iucv_irq_data[cpu] = NULL;
572 			return NOTIFY_BAD;
573 		}
574 		break;
575 	case CPU_UP_CANCELED:
576 	case CPU_UP_CANCELED_FROZEN:
577 	case CPU_DEAD:
578 	case CPU_DEAD_FROZEN:
579 		kfree(iucv_param[cpu]);
580 		iucv_param[cpu] = NULL;
581 		kfree(iucv_irq_data[cpu]);
582 		iucv_irq_data[cpu] = NULL;
583 		break;
584 	case CPU_ONLINE:
585 	case CPU_ONLINE_FROZEN:
586 	case CPU_DOWN_FAILED:
587 	case CPU_DOWN_FAILED_FROZEN:
588 		smp_call_function_single(cpu, iucv_declare_cpu, NULL, 1);
589 		break;
590 	case CPU_DOWN_PREPARE:
591 	case CPU_DOWN_PREPARE_FROZEN:
592 		cpumask = iucv_buffer_cpumask;
593 		cpu_clear(cpu, cpumask);
594 		if (cpus_empty(cpumask))
595 			/* Can't offline last IUCV enabled cpu. */
596 			return NOTIFY_BAD;
597 		smp_call_function_single(cpu, iucv_retrieve_cpu, NULL, 1);
598 		if (cpus_empty(iucv_irq_cpumask))
599 			smp_call_function_single(first_cpu(iucv_buffer_cpumask),
600 						 iucv_allow_cpu, NULL, 1);
601 		break;
602 	}
603 	return NOTIFY_OK;
604 }
605 
606 static struct notifier_block __refdata iucv_cpu_notifier = {
607 	.notifier_call = iucv_cpu_notify,
608 };
609 
610 /**
611  * iucv_sever_pathid
612  * @pathid: path identification number.
613  * @userdata: 16-bytes of user data.
614  *
615  * Sever an iucv path to free up the pathid. Used internally.
616  */
617 static int iucv_sever_pathid(u16 pathid, u8 userdata[16])
618 {
619 	union iucv_param *parm;
620 
621 	parm = iucv_param[smp_processor_id()];
622 	memset(parm, 0, sizeof(union iucv_param));
623 	if (userdata)
624 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
625 	parm->ctrl.ippathid = pathid;
626 	return iucv_call_b2f0(IUCV_SEVER, parm);
627 }
628 
629 /**
630  * __iucv_cleanup_queue
631  * @dummy: unused dummy argument
632  *
633  * Nop function called via smp_call_function to force work items from
634  * pending external iucv interrupts to the work queue.
635  */
636 static void __iucv_cleanup_queue(void *dummy)
637 {
638 }
639 
640 /**
641  * iucv_cleanup_queue
642  *
643  * Function called after a path has been severed to find all remaining
644  * work items for the now stale pathid. The caller needs to hold the
645  * iucv_table_lock.
646  */
647 static void iucv_cleanup_queue(void)
648 {
649 	struct iucv_irq_list *p, *n;
650 
651 	/*
652 	 * When a path is severed, the pathid can be reused immediatly
653 	 * on a iucv connect or a connection pending interrupt. Remove
654 	 * all entries from the task queue that refer to a stale pathid
655 	 * (iucv_path_table[ix] == NULL). Only then do the iucv connect
656 	 * or deliver the connection pending interrupt. To get all the
657 	 * pending interrupts force them to the work queue by calling
658 	 * an empty function on all cpus.
659 	 */
660 	smp_call_function(__iucv_cleanup_queue, NULL, 1);
661 	spin_lock_irq(&iucv_queue_lock);
662 	list_for_each_entry_safe(p, n, &iucv_task_queue, list) {
663 		/* Remove stale work items from the task queue. */
664 		if (iucv_path_table[p->data.ippathid] == NULL) {
665 			list_del(&p->list);
666 			kfree(p);
667 		}
668 	}
669 	spin_unlock_irq(&iucv_queue_lock);
670 }
671 
672 /**
673  * iucv_register:
674  * @handler: address of iucv handler structure
675  * @smp: != 0 indicates that the handler can deal with out of order messages
676  *
677  * Registers a driver with IUCV.
678  *
679  * Returns 0 on success, -ENOMEM if the memory allocation for the pathid
680  * table failed, or -EIO if IUCV_DECLARE_BUFFER failed on all cpus.
681  */
682 int iucv_register(struct iucv_handler *handler, int smp)
683 {
684 	int rc;
685 
686 	if (!iucv_available)
687 		return -ENOSYS;
688 	mutex_lock(&iucv_register_mutex);
689 	if (!smp)
690 		iucv_nonsmp_handler++;
691 	if (list_empty(&iucv_handler_list)) {
692 		rc = iucv_enable();
693 		if (rc)
694 			goto out_mutex;
695 	} else if (!smp && iucv_nonsmp_handler == 1)
696 		iucv_setmask_up();
697 	INIT_LIST_HEAD(&handler->paths);
698 
699 	spin_lock_bh(&iucv_table_lock);
700 	list_add_tail(&handler->list, &iucv_handler_list);
701 	spin_unlock_bh(&iucv_table_lock);
702 	rc = 0;
703 out_mutex:
704 	mutex_unlock(&iucv_register_mutex);
705 	return rc;
706 }
707 EXPORT_SYMBOL(iucv_register);
708 
709 /**
710  * iucv_unregister
711  * @handler:  address of iucv handler structure
712  * @smp: != 0 indicates that the handler can deal with out of order messages
713  *
714  * Unregister driver from IUCV.
715  */
716 void iucv_unregister(struct iucv_handler *handler, int smp)
717 {
718 	struct iucv_path *p, *n;
719 
720 	mutex_lock(&iucv_register_mutex);
721 	spin_lock_bh(&iucv_table_lock);
722 	/* Remove handler from the iucv_handler_list. */
723 	list_del_init(&handler->list);
724 	/* Sever all pathids still refering to the handler. */
725 	list_for_each_entry_safe(p, n, &handler->paths, list) {
726 		iucv_sever_pathid(p->pathid, NULL);
727 		iucv_path_table[p->pathid] = NULL;
728 		list_del(&p->list);
729 		iucv_path_free(p);
730 	}
731 	spin_unlock_bh(&iucv_table_lock);
732 	if (!smp)
733 		iucv_nonsmp_handler--;
734 	if (list_empty(&iucv_handler_list))
735 		iucv_disable();
736 	else if (!smp && iucv_nonsmp_handler == 0)
737 		iucv_setmask_mp();
738 	mutex_unlock(&iucv_register_mutex);
739 }
740 EXPORT_SYMBOL(iucv_unregister);
741 
742 /**
743  * iucv_path_accept
744  * @path: address of iucv path structure
745  * @handler: address of iucv handler structure
746  * @userdata: 16 bytes of data reflected to the communication partner
747  * @private: private data passed to interrupt handlers for this path
748  *
749  * This function is issued after the user received a connection pending
750  * external interrupt and now wishes to complete the IUCV communication path.
751  *
752  * Returns the result of the CP IUCV call.
753  */
754 int iucv_path_accept(struct iucv_path *path, struct iucv_handler *handler,
755 		     u8 userdata[16], void *private)
756 {
757 	union iucv_param *parm;
758 	int rc;
759 
760 	local_bh_disable();
761 	/* Prepare parameter block. */
762 	parm = iucv_param[smp_processor_id()];
763 	memset(parm, 0, sizeof(union iucv_param));
764 	parm->ctrl.ippathid = path->pathid;
765 	parm->ctrl.ipmsglim = path->msglim;
766 	if (userdata)
767 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
768 	parm->ctrl.ipflags1 = path->flags;
769 
770 	rc = iucv_call_b2f0(IUCV_ACCEPT, parm);
771 	if (!rc) {
772 		path->private = private;
773 		path->msglim = parm->ctrl.ipmsglim;
774 		path->flags = parm->ctrl.ipflags1;
775 	}
776 	local_bh_enable();
777 	return rc;
778 }
779 EXPORT_SYMBOL(iucv_path_accept);
780 
781 /**
782  * iucv_path_connect
783  * @path: address of iucv path structure
784  * @handler: address of iucv handler structure
785  * @userid: 8-byte user identification
786  * @system: 8-byte target system identification
787  * @userdata: 16 bytes of data reflected to the communication partner
788  * @private: private data passed to interrupt handlers for this path
789  *
790  * This function establishes an IUCV path. Although the connect may complete
791  * successfully, you are not able to use the path until you receive an IUCV
792  * Connection Complete external interrupt.
793  *
794  * Returns the result of the CP IUCV call.
795  */
796 int iucv_path_connect(struct iucv_path *path, struct iucv_handler *handler,
797 		      u8 userid[8], u8 system[8], u8 userdata[16],
798 		      void *private)
799 {
800 	union iucv_param *parm;
801 	int rc;
802 
803 	spin_lock_bh(&iucv_table_lock);
804 	iucv_cleanup_queue();
805 	parm = iucv_param[smp_processor_id()];
806 	memset(parm, 0, sizeof(union iucv_param));
807 	parm->ctrl.ipmsglim = path->msglim;
808 	parm->ctrl.ipflags1 = path->flags;
809 	if (userid) {
810 		memcpy(parm->ctrl.ipvmid, userid, sizeof(parm->ctrl.ipvmid));
811 		ASCEBC(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
812 		EBC_TOUPPER(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
813 	}
814 	if (system) {
815 		memcpy(parm->ctrl.iptarget, system,
816 		       sizeof(parm->ctrl.iptarget));
817 		ASCEBC(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
818 		EBC_TOUPPER(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
819 	}
820 	if (userdata)
821 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
822 
823 	rc = iucv_call_b2f0(IUCV_CONNECT, parm);
824 	if (!rc) {
825 		if (parm->ctrl.ippathid < iucv_max_pathid) {
826 			path->pathid = parm->ctrl.ippathid;
827 			path->msglim = parm->ctrl.ipmsglim;
828 			path->flags = parm->ctrl.ipflags1;
829 			path->handler = handler;
830 			path->private = private;
831 			list_add_tail(&path->list, &handler->paths);
832 			iucv_path_table[path->pathid] = path;
833 		} else {
834 			iucv_sever_pathid(parm->ctrl.ippathid,
835 					  iucv_error_pathid);
836 			rc = -EIO;
837 		}
838 	}
839 	spin_unlock_bh(&iucv_table_lock);
840 	return rc;
841 }
842 EXPORT_SYMBOL(iucv_path_connect);
843 
844 /**
845  * iucv_path_quiesce:
846  * @path: address of iucv path structure
847  * @userdata: 16 bytes of data reflected to the communication partner
848  *
849  * This function temporarily suspends incoming messages on an IUCV path.
850  * You can later reactivate the path by invoking the iucv_resume function.
851  *
852  * Returns the result from the CP IUCV call.
853  */
854 int iucv_path_quiesce(struct iucv_path *path, u8 userdata[16])
855 {
856 	union iucv_param *parm;
857 	int rc;
858 
859 	local_bh_disable();
860 	parm = iucv_param[smp_processor_id()];
861 	memset(parm, 0, sizeof(union iucv_param));
862 	if (userdata)
863 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
864 	parm->ctrl.ippathid = path->pathid;
865 	rc = iucv_call_b2f0(IUCV_QUIESCE, parm);
866 	local_bh_enable();
867 	return rc;
868 }
869 EXPORT_SYMBOL(iucv_path_quiesce);
870 
871 /**
872  * iucv_path_resume:
873  * @path: address of iucv path structure
874  * @userdata: 16 bytes of data reflected to the communication partner
875  *
876  * This function resumes incoming messages on an IUCV path that has
877  * been stopped with iucv_path_quiesce.
878  *
879  * Returns the result from the CP IUCV call.
880  */
881 int iucv_path_resume(struct iucv_path *path, u8 userdata[16])
882 {
883 	union iucv_param *parm;
884 	int rc;
885 
886 	local_bh_disable();
887 	parm = iucv_param[smp_processor_id()];
888 	memset(parm, 0, sizeof(union iucv_param));
889 	if (userdata)
890 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
891 	parm->ctrl.ippathid = path->pathid;
892 	rc = iucv_call_b2f0(IUCV_RESUME, parm);
893 	local_bh_enable();
894 	return rc;
895 }
896 
897 /**
898  * iucv_path_sever
899  * @path: address of iucv path structure
900  * @userdata: 16 bytes of data reflected to the communication partner
901  *
902  * This function terminates an IUCV path.
903  *
904  * Returns the result from the CP IUCV call.
905  */
906 int iucv_path_sever(struct iucv_path *path, u8 userdata[16])
907 {
908 	int rc;
909 
910 	preempt_disable();
911 	if (iucv_active_cpu != smp_processor_id())
912 		spin_lock_bh(&iucv_table_lock);
913 	rc = iucv_sever_pathid(path->pathid, userdata);
914 	if (!rc) {
915 		iucv_path_table[path->pathid] = NULL;
916 		list_del_init(&path->list);
917 	}
918 	if (iucv_active_cpu != smp_processor_id())
919 		spin_unlock_bh(&iucv_table_lock);
920 	preempt_enable();
921 	return rc;
922 }
923 EXPORT_SYMBOL(iucv_path_sever);
924 
925 /**
926  * iucv_message_purge
927  * @path: address of iucv path structure
928  * @msg: address of iucv msg structure
929  * @srccls: source class of message
930  *
931  * Cancels a message you have sent.
932  *
933  * Returns the result from the CP IUCV call.
934  */
935 int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg,
936 		       u32 srccls)
937 {
938 	union iucv_param *parm;
939 	int rc;
940 
941 	local_bh_disable();
942 	parm = iucv_param[smp_processor_id()];
943 	memset(parm, 0, sizeof(union iucv_param));
944 	parm->purge.ippathid = path->pathid;
945 	parm->purge.ipmsgid = msg->id;
946 	parm->purge.ipsrccls = srccls;
947 	parm->purge.ipflags1 = IUCV_IPSRCCLS | IUCV_IPFGMID | IUCV_IPFGPID;
948 	rc = iucv_call_b2f0(IUCV_PURGE, parm);
949 	if (!rc) {
950 		msg->audit = (*(u32 *) &parm->purge.ipaudit) >> 8;
951 		msg->tag = parm->purge.ipmsgtag;
952 	}
953 	local_bh_enable();
954 	return rc;
955 }
956 EXPORT_SYMBOL(iucv_message_purge);
957 
958 /**
959  * iucv_message_receive
960  * @path: address of iucv path structure
961  * @msg: address of iucv msg structure
962  * @flags: how the message is received (IUCV_IPBUFLST)
963  * @buffer: address of data buffer or address of struct iucv_array
964  * @size: length of data buffer
965  * @residual:
966  *
967  * This function receives messages that are being sent to you over
968  * established paths. This function will deal with RMDATA messages
969  * embedded in struct iucv_message as well.
970  *
971  * Returns the result from the CP IUCV call.
972  */
973 int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
974 			 u8 flags, void *buffer, size_t size, size_t *residual)
975 {
976 	union iucv_param *parm;
977 	struct iucv_array *array;
978 	u8 *rmmsg;
979 	size_t copy;
980 	int rc;
981 
982 	if (msg->flags & IUCV_IPRMDATA) {
983 		/*
984 		 * Message is 8 bytes long and has been stored to the
985 		 * message descriptor itself.
986 		 */
987 		rc = (size < 8) ? 5 : 0;
988 		if (residual)
989 			*residual = abs(size - 8);
990 		rmmsg = msg->rmmsg;
991 		if (flags & IUCV_IPBUFLST) {
992 			/* Copy to struct iucv_array. */
993 			size = (size < 8) ? size : 8;
994 			for (array = buffer; size > 0; array++) {
995 				copy = min_t(size_t, size, array->length);
996 				memcpy((u8 *)(addr_t) array->address,
997 				       rmmsg, copy);
998 				rmmsg += copy;
999 				size -= copy;
1000 			}
1001 		} else {
1002 			/* Copy to direct buffer. */
1003 			memcpy(buffer, rmmsg, min_t(size_t, size, 8));
1004 		}
1005 		return 0;
1006 	}
1007 
1008 	local_bh_disable();
1009 	parm = iucv_param[smp_processor_id()];
1010 	memset(parm, 0, sizeof(union iucv_param));
1011 	parm->db.ipbfadr1 = (u32)(addr_t) buffer;
1012 	parm->db.ipbfln1f = (u32) size;
1013 	parm->db.ipmsgid = msg->id;
1014 	parm->db.ippathid = path->pathid;
1015 	parm->db.iptrgcls = msg->class;
1016 	parm->db.ipflags1 = (flags | IUCV_IPFGPID |
1017 			     IUCV_IPFGMID | IUCV_IPTRGCLS);
1018 	rc = iucv_call_b2f0(IUCV_RECEIVE, parm);
1019 	if (!rc || rc == 5) {
1020 		msg->flags = parm->db.ipflags1;
1021 		if (residual)
1022 			*residual = parm->db.ipbfln1f;
1023 	}
1024 	local_bh_enable();
1025 	return rc;
1026 }
1027 EXPORT_SYMBOL(iucv_message_receive);
1028 
1029 /**
1030  * iucv_message_reject
1031  * @path: address of iucv path structure
1032  * @msg: address of iucv msg structure
1033  *
1034  * The reject function refuses a specified message. Between the time you
1035  * are notified of a message and the time that you complete the message,
1036  * the message may be rejected.
1037  *
1038  * Returns the result from the CP IUCV call.
1039  */
1040 int iucv_message_reject(struct iucv_path *path, struct iucv_message *msg)
1041 {
1042 	union iucv_param *parm;
1043 	int rc;
1044 
1045 	local_bh_disable();
1046 	parm = iucv_param[smp_processor_id()];
1047 	memset(parm, 0, sizeof(union iucv_param));
1048 	parm->db.ippathid = path->pathid;
1049 	parm->db.ipmsgid = msg->id;
1050 	parm->db.iptrgcls = msg->class;
1051 	parm->db.ipflags1 = (IUCV_IPTRGCLS | IUCV_IPFGMID | IUCV_IPFGPID);
1052 	rc = iucv_call_b2f0(IUCV_REJECT, parm);
1053 	local_bh_enable();
1054 	return rc;
1055 }
1056 EXPORT_SYMBOL(iucv_message_reject);
1057 
1058 /**
1059  * iucv_message_reply
1060  * @path: address of iucv path structure
1061  * @msg: address of iucv msg structure
1062  * @flags: how the reply is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1063  * @reply: address of reply data buffer or address of struct iucv_array
1064  * @size: length of reply data buffer
1065  *
1066  * This function responds to the two-way messages that you receive. You
1067  * must identify completely the message to which you wish to reply. ie,
1068  * pathid, msgid, and trgcls. Prmmsg signifies the data is moved into
1069  * the parameter list.
1070  *
1071  * Returns the result from the CP IUCV call.
1072  */
1073 int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg,
1074 		       u8 flags, void *reply, size_t size)
1075 {
1076 	union iucv_param *parm;
1077 	int rc;
1078 
1079 	local_bh_disable();
1080 	parm = iucv_param[smp_processor_id()];
1081 	memset(parm, 0, sizeof(union iucv_param));
1082 	if (flags & IUCV_IPRMDATA) {
1083 		parm->dpl.ippathid = path->pathid;
1084 		parm->dpl.ipflags1 = flags;
1085 		parm->dpl.ipmsgid = msg->id;
1086 		parm->dpl.iptrgcls = msg->class;
1087 		memcpy(parm->dpl.iprmmsg, reply, min_t(size_t, size, 8));
1088 	} else {
1089 		parm->db.ipbfadr1 = (u32)(addr_t) reply;
1090 		parm->db.ipbfln1f = (u32) size;
1091 		parm->db.ippathid = path->pathid;
1092 		parm->db.ipflags1 = flags;
1093 		parm->db.ipmsgid = msg->id;
1094 		parm->db.iptrgcls = msg->class;
1095 	}
1096 	rc = iucv_call_b2f0(IUCV_REPLY, parm);
1097 	local_bh_enable();
1098 	return rc;
1099 }
1100 EXPORT_SYMBOL(iucv_message_reply);
1101 
1102 /**
1103  * iucv_message_send
1104  * @path: address of iucv path structure
1105  * @msg: address of iucv msg structure
1106  * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1107  * @srccls: source class of message
1108  * @buffer: address of send buffer or address of struct iucv_array
1109  * @size: length of send buffer
1110  *
1111  * This function transmits data to another application. Data to be
1112  * transmitted is in a buffer and this is a one-way message and the
1113  * receiver will not reply to the message.
1114  *
1115  * Returns the result from the CP IUCV call.
1116  */
1117 int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
1118 		      u8 flags, u32 srccls, void *buffer, size_t size)
1119 {
1120 	union iucv_param *parm;
1121 	int rc;
1122 
1123 	local_bh_disable();
1124 	parm = iucv_param[smp_processor_id()];
1125 	memset(parm, 0, sizeof(union iucv_param));
1126 	if (flags & IUCV_IPRMDATA) {
1127 		/* Message of 8 bytes can be placed into the parameter list. */
1128 		parm->dpl.ippathid = path->pathid;
1129 		parm->dpl.ipflags1 = flags | IUCV_IPNORPY;
1130 		parm->dpl.iptrgcls = msg->class;
1131 		parm->dpl.ipsrccls = srccls;
1132 		parm->dpl.ipmsgtag = msg->tag;
1133 		memcpy(parm->dpl.iprmmsg, buffer, 8);
1134 	} else {
1135 		parm->db.ipbfadr1 = (u32)(addr_t) buffer;
1136 		parm->db.ipbfln1f = (u32) size;
1137 		parm->db.ippathid = path->pathid;
1138 		parm->db.ipflags1 = flags | IUCV_IPNORPY;
1139 		parm->db.iptrgcls = msg->class;
1140 		parm->db.ipsrccls = srccls;
1141 		parm->db.ipmsgtag = msg->tag;
1142 	}
1143 	rc = iucv_call_b2f0(IUCV_SEND, parm);
1144 	if (!rc)
1145 		msg->id = parm->db.ipmsgid;
1146 	local_bh_enable();
1147 	return rc;
1148 }
1149 EXPORT_SYMBOL(iucv_message_send);
1150 
1151 /**
1152  * iucv_message_send2way
1153  * @path: address of iucv path structure
1154  * @msg: address of iucv msg structure
1155  * @flags: how the message is sent and the reply is received
1156  *	   (IUCV_IPRMDATA, IUCV_IPBUFLST, IUCV_IPPRTY, IUCV_ANSLST)
1157  * @srccls: source class of message
1158  * @buffer: address of send buffer or address of struct iucv_array
1159  * @size: length of send buffer
1160  * @ansbuf: address of answer buffer or address of struct iucv_array
1161  * @asize: size of reply buffer
1162  *
1163  * This function transmits data to another application. Data to be
1164  * transmitted is in a buffer. The receiver of the send is expected to
1165  * reply to the message and a buffer is provided into which IUCV moves
1166  * the reply to this message.
1167  *
1168  * Returns the result from the CP IUCV call.
1169  */
1170 int iucv_message_send2way(struct iucv_path *path, struct iucv_message *msg,
1171 			  u8 flags, u32 srccls, void *buffer, size_t size,
1172 			  void *answer, size_t asize, size_t *residual)
1173 {
1174 	union iucv_param *parm;
1175 	int rc;
1176 
1177 	local_bh_disable();
1178 	parm = iucv_param[smp_processor_id()];
1179 	memset(parm, 0, sizeof(union iucv_param));
1180 	if (flags & IUCV_IPRMDATA) {
1181 		parm->dpl.ippathid = path->pathid;
1182 		parm->dpl.ipflags1 = path->flags;	/* priority message */
1183 		parm->dpl.iptrgcls = msg->class;
1184 		parm->dpl.ipsrccls = srccls;
1185 		parm->dpl.ipmsgtag = msg->tag;
1186 		parm->dpl.ipbfadr2 = (u32)(addr_t) answer;
1187 		parm->dpl.ipbfln2f = (u32) asize;
1188 		memcpy(parm->dpl.iprmmsg, buffer, 8);
1189 	} else {
1190 		parm->db.ippathid = path->pathid;
1191 		parm->db.ipflags1 = path->flags;	/* priority message */
1192 		parm->db.iptrgcls = msg->class;
1193 		parm->db.ipsrccls = srccls;
1194 		parm->db.ipmsgtag = msg->tag;
1195 		parm->db.ipbfadr1 = (u32)(addr_t) buffer;
1196 		parm->db.ipbfln1f = (u32) size;
1197 		parm->db.ipbfadr2 = (u32)(addr_t) answer;
1198 		parm->db.ipbfln2f = (u32) asize;
1199 	}
1200 	rc = iucv_call_b2f0(IUCV_SEND, parm);
1201 	if (!rc)
1202 		msg->id = parm->db.ipmsgid;
1203 	local_bh_enable();
1204 	return rc;
1205 }
1206 EXPORT_SYMBOL(iucv_message_send2way);
1207 
1208 /**
1209  * iucv_path_pending
1210  * @data: Pointer to external interrupt buffer
1211  *
1212  * Process connection pending work item. Called from tasklet while holding
1213  * iucv_table_lock.
1214  */
1215 struct iucv_path_pending {
1216 	u16 ippathid;
1217 	u8  ipflags1;
1218 	u8  iptype;
1219 	u16 ipmsglim;
1220 	u16 res1;
1221 	u8  ipvmid[8];
1222 	u8  ipuser[16];
1223 	u32 res3;
1224 	u8  ippollfg;
1225 	u8  res4[3];
1226 } __attribute__ ((packed));
1227 
1228 static void iucv_path_pending(struct iucv_irq_data *data)
1229 {
1230 	struct iucv_path_pending *ipp = (void *) data;
1231 	struct iucv_handler *handler;
1232 	struct iucv_path *path;
1233 	char *error;
1234 
1235 	BUG_ON(iucv_path_table[ipp->ippathid]);
1236 	/* New pathid, handler found. Create a new path struct. */
1237 	error = iucv_error_no_memory;
1238 	path = iucv_path_alloc(ipp->ipmsglim, ipp->ipflags1, GFP_ATOMIC);
1239 	if (!path)
1240 		goto out_sever;
1241 	path->pathid = ipp->ippathid;
1242 	iucv_path_table[path->pathid] = path;
1243 	EBCASC(ipp->ipvmid, 8);
1244 
1245 	/* Call registered handler until one is found that wants the path. */
1246 	list_for_each_entry(handler, &iucv_handler_list, list) {
1247 		if (!handler->path_pending)
1248 			continue;
1249 		/*
1250 		 * Add path to handler to allow a call to iucv_path_sever
1251 		 * inside the path_pending function. If the handler returns
1252 		 * an error remove the path from the handler again.
1253 		 */
1254 		list_add(&path->list, &handler->paths);
1255 		path->handler = handler;
1256 		if (!handler->path_pending(path, ipp->ipvmid, ipp->ipuser))
1257 			return;
1258 		list_del(&path->list);
1259 		path->handler = NULL;
1260 	}
1261 	/* No handler wanted the path. */
1262 	iucv_path_table[path->pathid] = NULL;
1263 	iucv_path_free(path);
1264 	error = iucv_error_no_listener;
1265 out_sever:
1266 	iucv_sever_pathid(ipp->ippathid, error);
1267 }
1268 
1269 /**
1270  * iucv_path_complete
1271  * @data: Pointer to external interrupt buffer
1272  *
1273  * Process connection complete work item. Called from tasklet while holding
1274  * iucv_table_lock.
1275  */
1276 struct iucv_path_complete {
1277 	u16 ippathid;
1278 	u8  ipflags1;
1279 	u8  iptype;
1280 	u16 ipmsglim;
1281 	u16 res1;
1282 	u8  res2[8];
1283 	u8  ipuser[16];
1284 	u32 res3;
1285 	u8  ippollfg;
1286 	u8  res4[3];
1287 } __attribute__ ((packed));
1288 
1289 static void iucv_path_complete(struct iucv_irq_data *data)
1290 {
1291 	struct iucv_path_complete *ipc = (void *) data;
1292 	struct iucv_path *path = iucv_path_table[ipc->ippathid];
1293 
1294 	if (path && path->handler && path->handler->path_complete)
1295 		path->handler->path_complete(path, ipc->ipuser);
1296 }
1297 
1298 /**
1299  * iucv_path_severed
1300  * @data: Pointer to external interrupt buffer
1301  *
1302  * Process connection severed work item. Called from tasklet while holding
1303  * iucv_table_lock.
1304  */
1305 struct iucv_path_severed {
1306 	u16 ippathid;
1307 	u8  res1;
1308 	u8  iptype;
1309 	u32 res2;
1310 	u8  res3[8];
1311 	u8  ipuser[16];
1312 	u32 res4;
1313 	u8  ippollfg;
1314 	u8  res5[3];
1315 } __attribute__ ((packed));
1316 
1317 static void iucv_path_severed(struct iucv_irq_data *data)
1318 {
1319 	struct iucv_path_severed *ips = (void *) data;
1320 	struct iucv_path *path = iucv_path_table[ips->ippathid];
1321 
1322 	if (!path || !path->handler)	/* Already severed */
1323 		return;
1324 	if (path->handler->path_severed)
1325 		path->handler->path_severed(path, ips->ipuser);
1326 	else {
1327 		iucv_sever_pathid(path->pathid, NULL);
1328 		iucv_path_table[path->pathid] = NULL;
1329 		list_del_init(&path->list);
1330 		iucv_path_free(path);
1331 	}
1332 }
1333 
1334 /**
1335  * iucv_path_quiesced
1336  * @data: Pointer to external interrupt buffer
1337  *
1338  * Process connection quiesced work item. Called from tasklet while holding
1339  * iucv_table_lock.
1340  */
1341 struct iucv_path_quiesced {
1342 	u16 ippathid;
1343 	u8  res1;
1344 	u8  iptype;
1345 	u32 res2;
1346 	u8  res3[8];
1347 	u8  ipuser[16];
1348 	u32 res4;
1349 	u8  ippollfg;
1350 	u8  res5[3];
1351 } __attribute__ ((packed));
1352 
1353 static void iucv_path_quiesced(struct iucv_irq_data *data)
1354 {
1355 	struct iucv_path_quiesced *ipq = (void *) data;
1356 	struct iucv_path *path = iucv_path_table[ipq->ippathid];
1357 
1358 	if (path && path->handler && path->handler->path_quiesced)
1359 		path->handler->path_quiesced(path, ipq->ipuser);
1360 }
1361 
1362 /**
1363  * iucv_path_resumed
1364  * @data: Pointer to external interrupt buffer
1365  *
1366  * Process connection resumed work item. Called from tasklet while holding
1367  * iucv_table_lock.
1368  */
1369 struct iucv_path_resumed {
1370 	u16 ippathid;
1371 	u8  res1;
1372 	u8  iptype;
1373 	u32 res2;
1374 	u8  res3[8];
1375 	u8  ipuser[16];
1376 	u32 res4;
1377 	u8  ippollfg;
1378 	u8  res5[3];
1379 } __attribute__ ((packed));
1380 
1381 static void iucv_path_resumed(struct iucv_irq_data *data)
1382 {
1383 	struct iucv_path_resumed *ipr = (void *) data;
1384 	struct iucv_path *path = iucv_path_table[ipr->ippathid];
1385 
1386 	if (path && path->handler && path->handler->path_resumed)
1387 		path->handler->path_resumed(path, ipr->ipuser);
1388 }
1389 
1390 /**
1391  * iucv_message_complete
1392  * @data: Pointer to external interrupt buffer
1393  *
1394  * Process message complete work item. Called from tasklet while holding
1395  * iucv_table_lock.
1396  */
1397 struct iucv_message_complete {
1398 	u16 ippathid;
1399 	u8  ipflags1;
1400 	u8  iptype;
1401 	u32 ipmsgid;
1402 	u32 ipaudit;
1403 	u8  iprmmsg[8];
1404 	u32 ipsrccls;
1405 	u32 ipmsgtag;
1406 	u32 res;
1407 	u32 ipbfln2f;
1408 	u8  ippollfg;
1409 	u8  res2[3];
1410 } __attribute__ ((packed));
1411 
1412 static void iucv_message_complete(struct iucv_irq_data *data)
1413 {
1414 	struct iucv_message_complete *imc = (void *) data;
1415 	struct iucv_path *path = iucv_path_table[imc->ippathid];
1416 	struct iucv_message msg;
1417 
1418 	if (path && path->handler && path->handler->message_complete) {
1419 		msg.flags = imc->ipflags1;
1420 		msg.id = imc->ipmsgid;
1421 		msg.audit = imc->ipaudit;
1422 		memcpy(msg.rmmsg, imc->iprmmsg, 8);
1423 		msg.class = imc->ipsrccls;
1424 		msg.tag = imc->ipmsgtag;
1425 		msg.length = imc->ipbfln2f;
1426 		path->handler->message_complete(path, &msg);
1427 	}
1428 }
1429 
1430 /**
1431  * iucv_message_pending
1432  * @data: Pointer to external interrupt buffer
1433  *
1434  * Process message pending work item. Called from tasklet while holding
1435  * iucv_table_lock.
1436  */
1437 struct iucv_message_pending {
1438 	u16 ippathid;
1439 	u8  ipflags1;
1440 	u8  iptype;
1441 	u32 ipmsgid;
1442 	u32 iptrgcls;
1443 	union {
1444 		u32 iprmmsg1_u32;
1445 		u8  iprmmsg1[4];
1446 	} ln1msg1;
1447 	union {
1448 		u32 ipbfln1f;
1449 		u8  iprmmsg2[4];
1450 	} ln1msg2;
1451 	u32 res1[3];
1452 	u32 ipbfln2f;
1453 	u8  ippollfg;
1454 	u8  res2[3];
1455 } __attribute__ ((packed));
1456 
1457 static void iucv_message_pending(struct iucv_irq_data *data)
1458 {
1459 	struct iucv_message_pending *imp = (void *) data;
1460 	struct iucv_path *path = iucv_path_table[imp->ippathid];
1461 	struct iucv_message msg;
1462 
1463 	if (path && path->handler && path->handler->message_pending) {
1464 		msg.flags = imp->ipflags1;
1465 		msg.id = imp->ipmsgid;
1466 		msg.class = imp->iptrgcls;
1467 		if (imp->ipflags1 & IUCV_IPRMDATA) {
1468 			memcpy(msg.rmmsg, imp->ln1msg1.iprmmsg1, 8);
1469 			msg.length = 8;
1470 		} else
1471 			msg.length = imp->ln1msg2.ipbfln1f;
1472 		msg.reply_size = imp->ipbfln2f;
1473 		path->handler->message_pending(path, &msg);
1474 	}
1475 }
1476 
1477 /**
1478  * iucv_tasklet_fn:
1479  *
1480  * This tasklet loops over the queue of irq buffers created by
1481  * iucv_external_interrupt, calls the appropriate action handler
1482  * and then frees the buffer.
1483  */
1484 static void iucv_tasklet_fn(unsigned long ignored)
1485 {
1486 	typedef void iucv_irq_fn(struct iucv_irq_data *);
1487 	static iucv_irq_fn *irq_fn[] = {
1488 		[0x02] = iucv_path_complete,
1489 		[0x03] = iucv_path_severed,
1490 		[0x04] = iucv_path_quiesced,
1491 		[0x05] = iucv_path_resumed,
1492 		[0x06] = iucv_message_complete,
1493 		[0x07] = iucv_message_complete,
1494 		[0x08] = iucv_message_pending,
1495 		[0x09] = iucv_message_pending,
1496 	};
1497 	LIST_HEAD(task_queue);
1498 	struct iucv_irq_list *p, *n;
1499 
1500 	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */
1501 	if (!spin_trylock(&iucv_table_lock)) {
1502 		tasklet_schedule(&iucv_tasklet);
1503 		return;
1504 	}
1505 	iucv_active_cpu = smp_processor_id();
1506 
1507 	spin_lock_irq(&iucv_queue_lock);
1508 	list_splice_init(&iucv_task_queue, &task_queue);
1509 	spin_unlock_irq(&iucv_queue_lock);
1510 
1511 	list_for_each_entry_safe(p, n, &task_queue, list) {
1512 		list_del_init(&p->list);
1513 		irq_fn[p->data.iptype](&p->data);
1514 		kfree(p);
1515 	}
1516 
1517 	iucv_active_cpu = -1;
1518 	spin_unlock(&iucv_table_lock);
1519 }
1520 
1521 /**
1522  * iucv_work_fn:
1523  *
1524  * This work function loops over the queue of path pending irq blocks
1525  * created by iucv_external_interrupt, calls the appropriate action
1526  * handler and then frees the buffer.
1527  */
1528 static void iucv_work_fn(struct work_struct *work)
1529 {
1530 	typedef void iucv_irq_fn(struct iucv_irq_data *);
1531 	LIST_HEAD(work_queue);
1532 	struct iucv_irq_list *p, *n;
1533 
1534 	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */
1535 	spin_lock_bh(&iucv_table_lock);
1536 	iucv_active_cpu = smp_processor_id();
1537 
1538 	spin_lock_irq(&iucv_queue_lock);
1539 	list_splice_init(&iucv_work_queue, &work_queue);
1540 	spin_unlock_irq(&iucv_queue_lock);
1541 
1542 	iucv_cleanup_queue();
1543 	list_for_each_entry_safe(p, n, &work_queue, list) {
1544 		list_del_init(&p->list);
1545 		iucv_path_pending(&p->data);
1546 		kfree(p);
1547 	}
1548 
1549 	iucv_active_cpu = -1;
1550 	spin_unlock_bh(&iucv_table_lock);
1551 }
1552 
1553 /**
1554  * iucv_external_interrupt
1555  * @code: irq code
1556  *
1557  * Handles external interrupts coming in from CP.
1558  * Places the interrupt buffer on a queue and schedules iucv_tasklet_fn().
1559  */
1560 static void iucv_external_interrupt(u16 code)
1561 {
1562 	struct iucv_irq_data *p;
1563 	struct iucv_irq_list *work;
1564 
1565 	p = iucv_irq_data[smp_processor_id()];
1566 	if (p->ippathid >= iucv_max_pathid) {
1567 		WARN_ON(p->ippathid >= iucv_max_pathid);
1568 		iucv_sever_pathid(p->ippathid, iucv_error_no_listener);
1569 		return;
1570 	}
1571 	BUG_ON(p->iptype  < 0x01 || p->iptype > 0x09);
1572 	work = kmalloc(sizeof(struct iucv_irq_list), GFP_ATOMIC);
1573 	if (!work) {
1574 		printk(KERN_WARNING "iucv_external_interrupt: out of memory\n");
1575 		return;
1576 	}
1577 	memcpy(&work->data, p, sizeof(work->data));
1578 	spin_lock(&iucv_queue_lock);
1579 	if (p->iptype == 0x01) {
1580 		/* Path pending interrupt. */
1581 		list_add_tail(&work->list, &iucv_work_queue);
1582 		schedule_work(&iucv_work);
1583 	} else {
1584 		/* The other interrupts. */
1585 		list_add_tail(&work->list, &iucv_task_queue);
1586 		tasklet_schedule(&iucv_tasklet);
1587 	}
1588 	spin_unlock(&iucv_queue_lock);
1589 }
1590 
1591 /**
1592  * iucv_init
1593  *
1594  * Allocates and initializes various data structures.
1595  */
1596 static int __init iucv_init(void)
1597 {
1598 	int rc;
1599 	int cpu;
1600 
1601 	if (!MACHINE_IS_VM) {
1602 		rc = -EPROTONOSUPPORT;
1603 		goto out;
1604 	}
1605 	rc = iucv_query_maxconn();
1606 	if (rc)
1607 		goto out;
1608 	rc = register_external_interrupt(0x4000, iucv_external_interrupt);
1609 	if (rc)
1610 		goto out;
1611 	iucv_root = s390_root_dev_register("iucv");
1612 	if (IS_ERR(iucv_root)) {
1613 		rc = PTR_ERR(iucv_root);
1614 		goto out_int;
1615 	}
1616 
1617 	for_each_online_cpu(cpu) {
1618 		/* Note: GFP_DMA used to get memory below 2G */
1619 		iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
1620 				     GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
1621 		if (!iucv_irq_data[cpu]) {
1622 			rc = -ENOMEM;
1623 			goto out_free;
1624 		}
1625 
1626 		/* Allocate parameter blocks. */
1627 		iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
1628 				  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
1629 		if (!iucv_param[cpu]) {
1630 			rc = -ENOMEM;
1631 			goto out_free;
1632 		}
1633 	}
1634 	rc = register_hotcpu_notifier(&iucv_cpu_notifier);
1635 	if (rc)
1636 		goto out_free;
1637 	ASCEBC(iucv_error_no_listener, 16);
1638 	ASCEBC(iucv_error_no_memory, 16);
1639 	ASCEBC(iucv_error_pathid, 16);
1640 	iucv_available = 1;
1641 	rc = bus_register(&iucv_bus);
1642 	if (rc)
1643 		goto out_cpu;
1644 	return 0;
1645 
1646 out_cpu:
1647 	unregister_hotcpu_notifier(&iucv_cpu_notifier);
1648 out_free:
1649 	for_each_possible_cpu(cpu) {
1650 		kfree(iucv_param[cpu]);
1651 		iucv_param[cpu] = NULL;
1652 		kfree(iucv_irq_data[cpu]);
1653 		iucv_irq_data[cpu] = NULL;
1654 	}
1655 	s390_root_dev_unregister(iucv_root);
1656 out_int:
1657 	unregister_external_interrupt(0x4000, iucv_external_interrupt);
1658 out:
1659 	return rc;
1660 }
1661 
1662 /**
1663  * iucv_exit
1664  *
1665  * Frees everything allocated from iucv_init.
1666  */
1667 static void __exit iucv_exit(void)
1668 {
1669 	struct iucv_irq_list *p, *n;
1670 	int cpu;
1671 
1672 	spin_lock_irq(&iucv_queue_lock);
1673 	list_for_each_entry_safe(p, n, &iucv_task_queue, list)
1674 		kfree(p);
1675 	list_for_each_entry_safe(p, n, &iucv_work_queue, list)
1676 		kfree(p);
1677 	spin_unlock_irq(&iucv_queue_lock);
1678 	unregister_hotcpu_notifier(&iucv_cpu_notifier);
1679 	for_each_possible_cpu(cpu) {
1680 		kfree(iucv_param[cpu]);
1681 		iucv_param[cpu] = NULL;
1682 		kfree(iucv_irq_data[cpu]);
1683 		iucv_irq_data[cpu] = NULL;
1684 	}
1685 	s390_root_dev_unregister(iucv_root);
1686 	bus_unregister(&iucv_bus);
1687 	unregister_external_interrupt(0x4000, iucv_external_interrupt);
1688 }
1689 
1690 subsys_initcall(iucv_init);
1691 module_exit(iucv_exit);
1692 
1693 MODULE_AUTHOR("(C) 2001 IBM Corp. by Fritz Elfert (felfert@millenux.com)");
1694 MODULE_DESCRIPTION("Linux for S/390 IUCV lowlevel driver");
1695 MODULE_LICENSE("GPL");
1696