xref: /linux/net/iucv/iucv.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * IUCV base infrastructure.
4  *
5  * Copyright IBM Corp. 2001, 2009
6  *
7  * Author(s):
8  *    Original source:
9  *	Alan Altmark (Alan_Altmark@us.ibm.com)	Sept. 2000
10  *	Xenia Tkatschow (xenia@us.ibm.com)
11  *    2Gb awareness and general cleanup:
12  *	Fritz Elfert (elfert@de.ibm.com, felfert@millenux.com)
13  *    Rewritten for af_iucv:
14  *	Martin Schwidefsky <schwidefsky@de.ibm.com>
15  *    PM functions:
16  *	Ursula Braun (ursula.braun@de.ibm.com)
17  *
18  * Documentation used:
19  *    The original source
20  *    CP Programming Service, IBM document # SC24-5760
21  */
22 
23 #define KMSG_COMPONENT "iucv"
24 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
25 
26 #include <linux/kernel_stat.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/spinlock.h>
30 #include <linux/kernel.h>
31 #include <linux/slab.h>
32 #include <linux/init.h>
33 #include <linux/interrupt.h>
34 #include <linux/list.h>
35 #include <linux/errno.h>
36 #include <linux/err.h>
37 #include <linux/device.h>
38 #include <linux/cpu.h>
39 #include <linux/reboot.h>
40 #include <net/iucv/iucv.h>
41 #include <linux/atomic.h>
42 #include <asm/ebcdic.h>
43 #include <asm/io.h>
44 #include <asm/irq.h>
45 #include <asm/smp.h>
46 
47 /*
48  * FLAGS:
49  * All flags are defined in the field IPFLAGS1 of each function
50  * and can be found in CP Programming Services.
51  * IPSRCCLS - Indicates you have specified a source class.
52  * IPTRGCLS - Indicates you have specified a target class.
53  * IPFGPID  - Indicates you have specified a pathid.
54  * IPFGMID  - Indicates you have specified a message ID.
55  * IPNORPY  - Indicates a one-way message. No reply expected.
56  * IPALL    - Indicates that all paths are affected.
57  */
58 #define IUCV_IPSRCCLS	0x01
59 #define IUCV_IPTRGCLS	0x01
60 #define IUCV_IPFGPID	0x02
61 #define IUCV_IPFGMID	0x04
62 #define IUCV_IPNORPY	0x10
63 #define IUCV_IPALL	0x80
64 
65 static int iucv_bus_match(struct device *dev, struct device_driver *drv)
66 {
67 	return 0;
68 }
69 
70 const struct bus_type iucv_bus = {
71 	.name = "iucv",
72 	.match = iucv_bus_match,
73 };
74 EXPORT_SYMBOL(iucv_bus);
75 
76 struct device *iucv_root;
77 EXPORT_SYMBOL(iucv_root);
78 
79 static int iucv_available;
80 
81 /* General IUCV interrupt structure */
82 struct iucv_irq_data {
83 	u16 ippathid;
84 	u8  ipflags1;
85 	u8  iptype;
86 	u32 res2[9];
87 };
88 
89 struct iucv_irq_list {
90 	struct list_head list;
91 	struct iucv_irq_data data;
92 };
93 
94 static struct iucv_irq_data *iucv_irq_data[NR_CPUS];
95 static cpumask_t iucv_buffer_cpumask = { CPU_BITS_NONE };
96 static cpumask_t iucv_irq_cpumask = { CPU_BITS_NONE };
97 
98 /*
99  * Queue of interrupt buffers lock for delivery via the tasklet
100  * (fast but can't call smp_call_function).
101  */
102 static LIST_HEAD(iucv_task_queue);
103 
104 /*
105  * The tasklet for fast delivery of iucv interrupts.
106  */
107 static void iucv_tasklet_fn(unsigned long);
108 static DECLARE_TASKLET_OLD(iucv_tasklet, iucv_tasklet_fn);
109 
110 /*
111  * Queue of interrupt buffers for delivery via a work queue
112  * (slower but can call smp_call_function).
113  */
114 static LIST_HEAD(iucv_work_queue);
115 
116 /*
117  * The work element to deliver path pending interrupts.
118  */
119 static void iucv_work_fn(struct work_struct *work);
120 static DECLARE_WORK(iucv_work, iucv_work_fn);
121 
122 /*
123  * Spinlock protecting task and work queue.
124  */
125 static DEFINE_SPINLOCK(iucv_queue_lock);
126 
127 enum iucv_command_codes {
128 	IUCV_QUERY = 0,
129 	IUCV_RETRIEVE_BUFFER = 2,
130 	IUCV_SEND = 4,
131 	IUCV_RECEIVE = 5,
132 	IUCV_REPLY = 6,
133 	IUCV_REJECT = 8,
134 	IUCV_PURGE = 9,
135 	IUCV_ACCEPT = 10,
136 	IUCV_CONNECT = 11,
137 	IUCV_DECLARE_BUFFER = 12,
138 	IUCV_QUIESCE = 13,
139 	IUCV_RESUME = 14,
140 	IUCV_SEVER = 15,
141 	IUCV_SETMASK = 16,
142 	IUCV_SETCONTROLMASK = 17,
143 };
144 
145 /*
146  * Error messages that are used with the iucv_sever function. They get
147  * converted to EBCDIC.
148  */
149 static char iucv_error_no_listener[16] = "NO LISTENER";
150 static char iucv_error_no_memory[16] = "NO MEMORY";
151 static char iucv_error_pathid[16] = "INVALID PATHID";
152 
153 /*
154  * iucv_handler_list: List of registered handlers.
155  */
156 static LIST_HEAD(iucv_handler_list);
157 
158 /*
159  * iucv_path_table: array of pointers to iucv_path structures.
160  */
161 static struct iucv_path **iucv_path_table;
162 static unsigned long iucv_max_pathid;
163 
164 /*
165  * iucv_lock: spinlock protecting iucv_handler_list and iucv_pathid_table
166  */
167 static DEFINE_SPINLOCK(iucv_table_lock);
168 
169 /*
170  * iucv_active_cpu: contains the number of the cpu executing the tasklet
171  * or the work handler. Needed for iucv_path_sever called from tasklet.
172  */
173 static int iucv_active_cpu = -1;
174 
175 /*
176  * Mutex and wait queue for iucv_register/iucv_unregister.
177  */
178 static DEFINE_MUTEX(iucv_register_mutex);
179 
180 /*
181  * Counter for number of non-smp capable handlers.
182  */
183 static int iucv_nonsmp_handler;
184 
185 /*
186  * IUCV control data structure. Used by iucv_path_accept, iucv_path_connect,
187  * iucv_path_quiesce and iucv_path_sever.
188  */
189 struct iucv_cmd_control {
190 	u16 ippathid;
191 	u8  ipflags1;
192 	u8  iprcode;
193 	u16 ipmsglim;
194 	u16 res1;
195 	u8  ipvmid[8];
196 	u8  ipuser[16];
197 	u8  iptarget[8];
198 } __attribute__ ((packed,aligned(8)));
199 
200 /*
201  * Data in parameter list iucv structure. Used by iucv_message_send,
202  * iucv_message_send2way and iucv_message_reply.
203  */
204 struct iucv_cmd_dpl {
205 	u16 ippathid;
206 	u8  ipflags1;
207 	u8  iprcode;
208 	u32 ipmsgid;
209 	u32 iptrgcls;
210 	u8  iprmmsg[8];
211 	u32 ipsrccls;
212 	u32 ipmsgtag;
213 	dma32_t ipbfadr2;
214 	u32 ipbfln2f;
215 	u32 res;
216 } __attribute__ ((packed,aligned(8)));
217 
218 /*
219  * Data in buffer iucv structure. Used by iucv_message_receive,
220  * iucv_message_reject, iucv_message_send, iucv_message_send2way
221  * and iucv_declare_cpu.
222  */
223 struct iucv_cmd_db {
224 	u16 ippathid;
225 	u8  ipflags1;
226 	u8  iprcode;
227 	u32 ipmsgid;
228 	u32 iptrgcls;
229 	dma32_t ipbfadr1;
230 	u32 ipbfln1f;
231 	u32 ipsrccls;
232 	u32 ipmsgtag;
233 	dma32_t ipbfadr2;
234 	u32 ipbfln2f;
235 	u32 res;
236 } __attribute__ ((packed,aligned(8)));
237 
238 /*
239  * Purge message iucv structure. Used by iucv_message_purge.
240  */
241 struct iucv_cmd_purge {
242 	u16 ippathid;
243 	u8  ipflags1;
244 	u8  iprcode;
245 	u32 ipmsgid;
246 	u8  ipaudit[3];
247 	u8  res1[5];
248 	u32 res2;
249 	u32 ipsrccls;
250 	u32 ipmsgtag;
251 	u32 res3[3];
252 } __attribute__ ((packed,aligned(8)));
253 
254 /*
255  * Set mask iucv structure. Used by iucv_enable_cpu.
256  */
257 struct iucv_cmd_set_mask {
258 	u8  ipmask;
259 	u8  res1[2];
260 	u8  iprcode;
261 	u32 res2[9];
262 } __attribute__ ((packed,aligned(8)));
263 
264 union iucv_param {
265 	struct iucv_cmd_control ctrl;
266 	struct iucv_cmd_dpl dpl;
267 	struct iucv_cmd_db db;
268 	struct iucv_cmd_purge purge;
269 	struct iucv_cmd_set_mask set_mask;
270 };
271 
272 /*
273  * Anchor for per-cpu IUCV command parameter block.
274  */
275 static union iucv_param *iucv_param[NR_CPUS];
276 static union iucv_param *iucv_param_irq[NR_CPUS];
277 
278 /**
279  * __iucv_call_b2f0
280  * @command: identifier of IUCV call to CP.
281  * @parm: pointer to a struct iucv_parm block
282  *
283  * Calls CP to execute IUCV commands.
284  *
285  * Returns the result of the CP IUCV call.
286  */
287 static inline int __iucv_call_b2f0(int command, union iucv_param *parm)
288 {
289 	unsigned long reg1 = virt_to_phys(parm);
290 	int cc;
291 
292 	asm volatile(
293 		"	lgr	0,%[reg0]\n"
294 		"	lgr	1,%[reg1]\n"
295 		"	.long	0xb2f01000\n"
296 		"	ipm	%[cc]\n"
297 		"	srl	%[cc],28\n"
298 		: [cc] "=&d" (cc), "+m" (*parm)
299 		: [reg0] "d" ((unsigned long)command),
300 		  [reg1] "d" (reg1)
301 		: "cc", "0", "1");
302 	return cc;
303 }
304 
305 static inline int iucv_call_b2f0(int command, union iucv_param *parm)
306 {
307 	int ccode;
308 
309 	ccode = __iucv_call_b2f0(command, parm);
310 	return ccode == 1 ? parm->ctrl.iprcode : ccode;
311 }
312 
313 /*
314  * iucv_query_maxconn
315  *
316  * Determines the maximum number of connections that may be established.
317  *
318  * Returns the maximum number of connections or -EPERM is IUCV is not
319  * available.
320  */
321 static int __iucv_query_maxconn(void *param, unsigned long *max_pathid)
322 {
323 	unsigned long reg1 = virt_to_phys(param);
324 	int cc;
325 
326 	asm volatile (
327 		"	lghi	0,%[cmd]\n"
328 		"	lgr	1,%[reg1]\n"
329 		"	.long	0xb2f01000\n"
330 		"	ipm	%[cc]\n"
331 		"	srl	%[cc],28\n"
332 		"	lgr	%[reg1],1\n"
333 		: [cc] "=&d" (cc), [reg1] "+&d" (reg1)
334 		: [cmd] "K" (IUCV_QUERY)
335 		: "cc", "0", "1");
336 	*max_pathid = reg1;
337 	return cc;
338 }
339 
340 static int iucv_query_maxconn(void)
341 {
342 	unsigned long max_pathid;
343 	void *param;
344 	int ccode;
345 
346 	param = kzalloc(sizeof(union iucv_param), GFP_KERNEL | GFP_DMA);
347 	if (!param)
348 		return -ENOMEM;
349 	ccode = __iucv_query_maxconn(param, &max_pathid);
350 	if (ccode == 0)
351 		iucv_max_pathid = max_pathid;
352 	kfree(param);
353 	return ccode ? -EPERM : 0;
354 }
355 
356 /**
357  * iucv_allow_cpu
358  * @data: unused
359  *
360  * Allow iucv interrupts on this cpu.
361  */
362 static void iucv_allow_cpu(void *data)
363 {
364 	int cpu = smp_processor_id();
365 	union iucv_param *parm;
366 
367 	/*
368 	 * Enable all iucv interrupts.
369 	 * ipmask contains bits for the different interrupts
370 	 *	0x80 - Flag to allow nonpriority message pending interrupts
371 	 *	0x40 - Flag to allow priority message pending interrupts
372 	 *	0x20 - Flag to allow nonpriority message completion interrupts
373 	 *	0x10 - Flag to allow priority message completion interrupts
374 	 *	0x08 - Flag to allow IUCV control interrupts
375 	 */
376 	parm = iucv_param_irq[cpu];
377 	memset(parm, 0, sizeof(union iucv_param));
378 	parm->set_mask.ipmask = 0xf8;
379 	iucv_call_b2f0(IUCV_SETMASK, parm);
380 
381 	/*
382 	 * Enable all iucv control interrupts.
383 	 * ipmask contains bits for the different interrupts
384 	 *	0x80 - Flag to allow pending connections interrupts
385 	 *	0x40 - Flag to allow connection complete interrupts
386 	 *	0x20 - Flag to allow connection severed interrupts
387 	 *	0x10 - Flag to allow connection quiesced interrupts
388 	 *	0x08 - Flag to allow connection resumed interrupts
389 	 */
390 	memset(parm, 0, sizeof(union iucv_param));
391 	parm->set_mask.ipmask = 0xf8;
392 	iucv_call_b2f0(IUCV_SETCONTROLMASK, parm);
393 	/* Set indication that iucv interrupts are allowed for this cpu. */
394 	cpumask_set_cpu(cpu, &iucv_irq_cpumask);
395 }
396 
397 /**
398  * iucv_block_cpu
399  * @data: unused
400  *
401  * Block iucv interrupts on this cpu.
402  */
403 static void iucv_block_cpu(void *data)
404 {
405 	int cpu = smp_processor_id();
406 	union iucv_param *parm;
407 
408 	/* Disable all iucv interrupts. */
409 	parm = iucv_param_irq[cpu];
410 	memset(parm, 0, sizeof(union iucv_param));
411 	iucv_call_b2f0(IUCV_SETMASK, parm);
412 
413 	/* Clear indication that iucv interrupts are allowed for this cpu. */
414 	cpumask_clear_cpu(cpu, &iucv_irq_cpumask);
415 }
416 
417 /**
418  * iucv_declare_cpu
419  * @data: unused
420  *
421  * Declare a interrupt buffer on this cpu.
422  */
423 static void iucv_declare_cpu(void *data)
424 {
425 	int cpu = smp_processor_id();
426 	union iucv_param *parm;
427 	int rc;
428 
429 	if (cpumask_test_cpu(cpu, &iucv_buffer_cpumask))
430 		return;
431 
432 	/* Declare interrupt buffer. */
433 	parm = iucv_param_irq[cpu];
434 	memset(parm, 0, sizeof(union iucv_param));
435 	parm->db.ipbfadr1 = virt_to_dma32(iucv_irq_data[cpu]);
436 	rc = iucv_call_b2f0(IUCV_DECLARE_BUFFER, parm);
437 	if (rc) {
438 		char *err = "Unknown";
439 		switch (rc) {
440 		case 0x03:
441 			err = "Directory error";
442 			break;
443 		case 0x0a:
444 			err = "Invalid length";
445 			break;
446 		case 0x13:
447 			err = "Buffer already exists";
448 			break;
449 		case 0x3e:
450 			err = "Buffer overlap";
451 			break;
452 		case 0x5c:
453 			err = "Paging or storage error";
454 			break;
455 		}
456 		pr_warn("Defining an interrupt buffer on CPU %i failed with 0x%02x (%s)\n",
457 			cpu, rc, err);
458 		return;
459 	}
460 
461 	/* Set indication that an iucv buffer exists for this cpu. */
462 	cpumask_set_cpu(cpu, &iucv_buffer_cpumask);
463 
464 	if (iucv_nonsmp_handler == 0 || cpumask_empty(&iucv_irq_cpumask))
465 		/* Enable iucv interrupts on this cpu. */
466 		iucv_allow_cpu(NULL);
467 	else
468 		/* Disable iucv interrupts on this cpu. */
469 		iucv_block_cpu(NULL);
470 }
471 
472 /**
473  * iucv_retrieve_cpu
474  * @data: unused
475  *
476  * Retrieve interrupt buffer on this cpu.
477  */
478 static void iucv_retrieve_cpu(void *data)
479 {
480 	int cpu = smp_processor_id();
481 	union iucv_param *parm;
482 
483 	if (!cpumask_test_cpu(cpu, &iucv_buffer_cpumask))
484 		return;
485 
486 	/* Block iucv interrupts. */
487 	iucv_block_cpu(NULL);
488 
489 	/* Retrieve interrupt buffer. */
490 	parm = iucv_param_irq[cpu];
491 	iucv_call_b2f0(IUCV_RETRIEVE_BUFFER, parm);
492 
493 	/* Clear indication that an iucv buffer exists for this cpu. */
494 	cpumask_clear_cpu(cpu, &iucv_buffer_cpumask);
495 }
496 
497 /*
498  * iucv_setmask_mp
499  *
500  * Allow iucv interrupts on all cpus.
501  */
502 static void iucv_setmask_mp(void)
503 {
504 	int cpu;
505 
506 	cpus_read_lock();
507 	for_each_online_cpu(cpu)
508 		/* Enable all cpus with a declared buffer. */
509 		if (cpumask_test_cpu(cpu, &iucv_buffer_cpumask) &&
510 		    !cpumask_test_cpu(cpu, &iucv_irq_cpumask))
511 			smp_call_function_single(cpu, iucv_allow_cpu,
512 						 NULL, 1);
513 	cpus_read_unlock();
514 }
515 
516 /*
517  * iucv_setmask_up
518  *
519  * Allow iucv interrupts on a single cpu.
520  */
521 static void iucv_setmask_up(void)
522 {
523 	cpumask_t cpumask;
524 	int cpu;
525 
526 	/* Disable all cpu but the first in cpu_irq_cpumask. */
527 	cpumask_copy(&cpumask, &iucv_irq_cpumask);
528 	cpumask_clear_cpu(cpumask_first(&iucv_irq_cpumask), &cpumask);
529 	for_each_cpu(cpu, &cpumask)
530 		smp_call_function_single(cpu, iucv_block_cpu, NULL, 1);
531 }
532 
533 /*
534  * iucv_enable
535  *
536  * This function makes iucv ready for use. It allocates the pathid
537  * table, declares an iucv interrupt buffer and enables the iucv
538  * interrupts. Called when the first user has registered an iucv
539  * handler.
540  */
541 static int iucv_enable(void)
542 {
543 	size_t alloc_size;
544 	int cpu, rc;
545 
546 	cpus_read_lock();
547 	rc = -ENOMEM;
548 	alloc_size = iucv_max_pathid * sizeof(*iucv_path_table);
549 	iucv_path_table = kzalloc(alloc_size, GFP_KERNEL);
550 	if (!iucv_path_table)
551 		goto out;
552 	/* Declare per cpu buffers. */
553 	rc = -EIO;
554 	for_each_online_cpu(cpu)
555 		smp_call_function_single(cpu, iucv_declare_cpu, NULL, 1);
556 	if (cpumask_empty(&iucv_buffer_cpumask))
557 		/* No cpu could declare an iucv buffer. */
558 		goto out;
559 	cpus_read_unlock();
560 	return 0;
561 out:
562 	kfree(iucv_path_table);
563 	iucv_path_table = NULL;
564 	cpus_read_unlock();
565 	return rc;
566 }
567 
568 /*
569  * iucv_disable
570  *
571  * This function shuts down iucv. It disables iucv interrupts, retrieves
572  * the iucv interrupt buffer and frees the pathid table. Called after the
573  * last user unregister its iucv handler.
574  */
575 static void iucv_disable(void)
576 {
577 	cpus_read_lock();
578 	on_each_cpu(iucv_retrieve_cpu, NULL, 1);
579 	kfree(iucv_path_table);
580 	iucv_path_table = NULL;
581 	cpus_read_unlock();
582 }
583 
584 static int iucv_cpu_dead(unsigned int cpu)
585 {
586 	kfree(iucv_param_irq[cpu]);
587 	iucv_param_irq[cpu] = NULL;
588 	kfree(iucv_param[cpu]);
589 	iucv_param[cpu] = NULL;
590 	kfree(iucv_irq_data[cpu]);
591 	iucv_irq_data[cpu] = NULL;
592 	return 0;
593 }
594 
595 static int iucv_cpu_prepare(unsigned int cpu)
596 {
597 	/* Note: GFP_DMA used to get memory below 2G */
598 	iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
599 			     GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
600 	if (!iucv_irq_data[cpu])
601 		goto out_free;
602 
603 	/* Allocate parameter blocks. */
604 	iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
605 			  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
606 	if (!iucv_param[cpu])
607 		goto out_free;
608 
609 	iucv_param_irq[cpu] = kmalloc_node(sizeof(union iucv_param),
610 			  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
611 	if (!iucv_param_irq[cpu])
612 		goto out_free;
613 
614 	return 0;
615 
616 out_free:
617 	iucv_cpu_dead(cpu);
618 	return -ENOMEM;
619 }
620 
621 static int iucv_cpu_online(unsigned int cpu)
622 {
623 	if (!iucv_path_table)
624 		return 0;
625 	iucv_declare_cpu(NULL);
626 	return 0;
627 }
628 
629 static int iucv_cpu_down_prep(unsigned int cpu)
630 {
631 	cpumask_t cpumask;
632 
633 	if (!iucv_path_table)
634 		return 0;
635 
636 	cpumask_copy(&cpumask, &iucv_buffer_cpumask);
637 	cpumask_clear_cpu(cpu, &cpumask);
638 	if (cpumask_empty(&cpumask))
639 		/* Can't offline last IUCV enabled cpu. */
640 		return -EINVAL;
641 
642 	iucv_retrieve_cpu(NULL);
643 	if (!cpumask_empty(&iucv_irq_cpumask))
644 		return 0;
645 	smp_call_function_single(cpumask_first(&iucv_buffer_cpumask),
646 				 iucv_allow_cpu, NULL, 1);
647 	return 0;
648 }
649 
650 /**
651  * iucv_sever_pathid
652  * @pathid: path identification number.
653  * @userdata: 16-bytes of user data.
654  *
655  * Sever an iucv path to free up the pathid. Used internally.
656  */
657 static int iucv_sever_pathid(u16 pathid, u8 *userdata)
658 {
659 	union iucv_param *parm;
660 
661 	parm = iucv_param_irq[smp_processor_id()];
662 	memset(parm, 0, sizeof(union iucv_param));
663 	if (userdata)
664 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
665 	parm->ctrl.ippathid = pathid;
666 	return iucv_call_b2f0(IUCV_SEVER, parm);
667 }
668 
669 /**
670  * __iucv_cleanup_queue
671  * @dummy: unused dummy argument
672  *
673  * Nop function called via smp_call_function to force work items from
674  * pending external iucv interrupts to the work queue.
675  */
676 static void __iucv_cleanup_queue(void *dummy)
677 {
678 }
679 
680 /**
681  * iucv_cleanup_queue
682  *
683  * Function called after a path has been severed to find all remaining
684  * work items for the now stale pathid. The caller needs to hold the
685  * iucv_table_lock.
686  */
687 static void iucv_cleanup_queue(void)
688 {
689 	struct iucv_irq_list *p, *n;
690 
691 	/*
692 	 * When a path is severed, the pathid can be reused immediately
693 	 * on a iucv connect or a connection pending interrupt. Remove
694 	 * all entries from the task queue that refer to a stale pathid
695 	 * (iucv_path_table[ix] == NULL). Only then do the iucv connect
696 	 * or deliver the connection pending interrupt. To get all the
697 	 * pending interrupts force them to the work queue by calling
698 	 * an empty function on all cpus.
699 	 */
700 	smp_call_function(__iucv_cleanup_queue, NULL, 1);
701 	spin_lock_irq(&iucv_queue_lock);
702 	list_for_each_entry_safe(p, n, &iucv_task_queue, list) {
703 		/* Remove stale work items from the task queue. */
704 		if (iucv_path_table[p->data.ippathid] == NULL) {
705 			list_del(&p->list);
706 			kfree(p);
707 		}
708 	}
709 	spin_unlock_irq(&iucv_queue_lock);
710 }
711 
712 /**
713  * iucv_register:
714  * @handler: address of iucv handler structure
715  * @smp: != 0 indicates that the handler can deal with out of order messages
716  *
717  * Registers a driver with IUCV.
718  *
719  * Returns 0 on success, -ENOMEM if the memory allocation for the pathid
720  * table failed, or -EIO if IUCV_DECLARE_BUFFER failed on all cpus.
721  */
722 int iucv_register(struct iucv_handler *handler, int smp)
723 {
724 	int rc;
725 
726 	if (!iucv_available)
727 		return -ENOSYS;
728 	mutex_lock(&iucv_register_mutex);
729 	if (!smp)
730 		iucv_nonsmp_handler++;
731 	if (list_empty(&iucv_handler_list)) {
732 		rc = iucv_enable();
733 		if (rc)
734 			goto out_mutex;
735 	} else if (!smp && iucv_nonsmp_handler == 1)
736 		iucv_setmask_up();
737 	INIT_LIST_HEAD(&handler->paths);
738 
739 	spin_lock_bh(&iucv_table_lock);
740 	list_add_tail(&handler->list, &iucv_handler_list);
741 	spin_unlock_bh(&iucv_table_lock);
742 	rc = 0;
743 out_mutex:
744 	mutex_unlock(&iucv_register_mutex);
745 	return rc;
746 }
747 EXPORT_SYMBOL(iucv_register);
748 
749 /**
750  * iucv_unregister
751  * @handler:  address of iucv handler structure
752  * @smp: != 0 indicates that the handler can deal with out of order messages
753  *
754  * Unregister driver from IUCV.
755  */
756 void iucv_unregister(struct iucv_handler *handler, int smp)
757 {
758 	struct iucv_path *p, *n;
759 
760 	mutex_lock(&iucv_register_mutex);
761 	spin_lock_bh(&iucv_table_lock);
762 	/* Remove handler from the iucv_handler_list. */
763 	list_del_init(&handler->list);
764 	/* Sever all pathids still referring to the handler. */
765 	list_for_each_entry_safe(p, n, &handler->paths, list) {
766 		iucv_sever_pathid(p->pathid, NULL);
767 		iucv_path_table[p->pathid] = NULL;
768 		list_del(&p->list);
769 		iucv_path_free(p);
770 	}
771 	spin_unlock_bh(&iucv_table_lock);
772 	if (!smp)
773 		iucv_nonsmp_handler--;
774 	if (list_empty(&iucv_handler_list))
775 		iucv_disable();
776 	else if (!smp && iucv_nonsmp_handler == 0)
777 		iucv_setmask_mp();
778 	mutex_unlock(&iucv_register_mutex);
779 }
780 EXPORT_SYMBOL(iucv_unregister);
781 
782 static int iucv_reboot_event(struct notifier_block *this,
783 			     unsigned long event, void *ptr)
784 {
785 	int i;
786 
787 	if (cpumask_empty(&iucv_irq_cpumask))
788 		return NOTIFY_DONE;
789 
790 	cpus_read_lock();
791 	on_each_cpu_mask(&iucv_irq_cpumask, iucv_block_cpu, NULL, 1);
792 	preempt_disable();
793 	for (i = 0; i < iucv_max_pathid; i++) {
794 		if (iucv_path_table[i])
795 			iucv_sever_pathid(i, NULL);
796 	}
797 	preempt_enable();
798 	cpus_read_unlock();
799 	iucv_disable();
800 	return NOTIFY_DONE;
801 }
802 
803 static struct notifier_block iucv_reboot_notifier = {
804 	.notifier_call = iucv_reboot_event,
805 };
806 
807 /**
808  * iucv_path_accept
809  * @path: address of iucv path structure
810  * @handler: address of iucv handler structure
811  * @userdata: 16 bytes of data reflected to the communication partner
812  * @private: private data passed to interrupt handlers for this path
813  *
814  * This function is issued after the user received a connection pending
815  * external interrupt and now wishes to complete the IUCV communication path.
816  *
817  * Returns the result of the CP IUCV call.
818  */
819 int iucv_path_accept(struct iucv_path *path, struct iucv_handler *handler,
820 		     u8 *userdata, void *private)
821 {
822 	union iucv_param *parm;
823 	int rc;
824 
825 	local_bh_disable();
826 	if (cpumask_empty(&iucv_buffer_cpumask)) {
827 		rc = -EIO;
828 		goto out;
829 	}
830 	/* Prepare parameter block. */
831 	parm = iucv_param[smp_processor_id()];
832 	memset(parm, 0, sizeof(union iucv_param));
833 	parm->ctrl.ippathid = path->pathid;
834 	parm->ctrl.ipmsglim = path->msglim;
835 	if (userdata)
836 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
837 	parm->ctrl.ipflags1 = path->flags;
838 
839 	rc = iucv_call_b2f0(IUCV_ACCEPT, parm);
840 	if (!rc) {
841 		path->private = private;
842 		path->msglim = parm->ctrl.ipmsglim;
843 		path->flags = parm->ctrl.ipflags1;
844 	}
845 out:
846 	local_bh_enable();
847 	return rc;
848 }
849 EXPORT_SYMBOL(iucv_path_accept);
850 
851 /**
852  * iucv_path_connect
853  * @path: address of iucv path structure
854  * @handler: address of iucv handler structure
855  * @userid: 8-byte user identification
856  * @system: 8-byte target system identification
857  * @userdata: 16 bytes of data reflected to the communication partner
858  * @private: private data passed to interrupt handlers for this path
859  *
860  * This function establishes an IUCV path. Although the connect may complete
861  * successfully, you are not able to use the path until you receive an IUCV
862  * Connection Complete external interrupt.
863  *
864  * Returns the result of the CP IUCV call.
865  */
866 int iucv_path_connect(struct iucv_path *path, struct iucv_handler *handler,
867 		      u8 *userid, u8 *system, u8 *userdata,
868 		      void *private)
869 {
870 	union iucv_param *parm;
871 	int rc;
872 
873 	spin_lock_bh(&iucv_table_lock);
874 	iucv_cleanup_queue();
875 	if (cpumask_empty(&iucv_buffer_cpumask)) {
876 		rc = -EIO;
877 		goto out;
878 	}
879 	parm = iucv_param[smp_processor_id()];
880 	memset(parm, 0, sizeof(union iucv_param));
881 	parm->ctrl.ipmsglim = path->msglim;
882 	parm->ctrl.ipflags1 = path->flags;
883 	if (userid) {
884 		memcpy(parm->ctrl.ipvmid, userid, sizeof(parm->ctrl.ipvmid));
885 		ASCEBC(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
886 		EBC_TOUPPER(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
887 	}
888 	if (system) {
889 		memcpy(parm->ctrl.iptarget, system,
890 		       sizeof(parm->ctrl.iptarget));
891 		ASCEBC(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
892 		EBC_TOUPPER(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
893 	}
894 	if (userdata)
895 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
896 
897 	rc = iucv_call_b2f0(IUCV_CONNECT, parm);
898 	if (!rc) {
899 		if (parm->ctrl.ippathid < iucv_max_pathid) {
900 			path->pathid = parm->ctrl.ippathid;
901 			path->msglim = parm->ctrl.ipmsglim;
902 			path->flags = parm->ctrl.ipflags1;
903 			path->handler = handler;
904 			path->private = private;
905 			list_add_tail(&path->list, &handler->paths);
906 			iucv_path_table[path->pathid] = path;
907 		} else {
908 			iucv_sever_pathid(parm->ctrl.ippathid,
909 					  iucv_error_pathid);
910 			rc = -EIO;
911 		}
912 	}
913 out:
914 	spin_unlock_bh(&iucv_table_lock);
915 	return rc;
916 }
917 EXPORT_SYMBOL(iucv_path_connect);
918 
919 /**
920  * iucv_path_quiesce:
921  * @path: address of iucv path structure
922  * @userdata: 16 bytes of data reflected to the communication partner
923  *
924  * This function temporarily suspends incoming messages on an IUCV path.
925  * You can later reactivate the path by invoking the iucv_resume function.
926  *
927  * Returns the result from the CP IUCV call.
928  */
929 int iucv_path_quiesce(struct iucv_path *path, u8 *userdata)
930 {
931 	union iucv_param *parm;
932 	int rc;
933 
934 	local_bh_disable();
935 	if (cpumask_empty(&iucv_buffer_cpumask)) {
936 		rc = -EIO;
937 		goto out;
938 	}
939 	parm = iucv_param[smp_processor_id()];
940 	memset(parm, 0, sizeof(union iucv_param));
941 	if (userdata)
942 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
943 	parm->ctrl.ippathid = path->pathid;
944 	rc = iucv_call_b2f0(IUCV_QUIESCE, parm);
945 out:
946 	local_bh_enable();
947 	return rc;
948 }
949 EXPORT_SYMBOL(iucv_path_quiesce);
950 
951 /**
952  * iucv_path_resume:
953  * @path: address of iucv path structure
954  * @userdata: 16 bytes of data reflected to the communication partner
955  *
956  * This function resumes incoming messages on an IUCV path that has
957  * been stopped with iucv_path_quiesce.
958  *
959  * Returns the result from the CP IUCV call.
960  */
961 int iucv_path_resume(struct iucv_path *path, u8 *userdata)
962 {
963 	union iucv_param *parm;
964 	int rc;
965 
966 	local_bh_disable();
967 	if (cpumask_empty(&iucv_buffer_cpumask)) {
968 		rc = -EIO;
969 		goto out;
970 	}
971 	parm = iucv_param[smp_processor_id()];
972 	memset(parm, 0, sizeof(union iucv_param));
973 	if (userdata)
974 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
975 	parm->ctrl.ippathid = path->pathid;
976 	rc = iucv_call_b2f0(IUCV_RESUME, parm);
977 out:
978 	local_bh_enable();
979 	return rc;
980 }
981 
982 /**
983  * iucv_path_sever
984  * @path: address of iucv path structure
985  * @userdata: 16 bytes of data reflected to the communication partner
986  *
987  * This function terminates an IUCV path.
988  *
989  * Returns the result from the CP IUCV call.
990  */
991 int iucv_path_sever(struct iucv_path *path, u8 *userdata)
992 {
993 	int rc;
994 
995 	preempt_disable();
996 	if (cpumask_empty(&iucv_buffer_cpumask)) {
997 		rc = -EIO;
998 		goto out;
999 	}
1000 	if (iucv_active_cpu != smp_processor_id())
1001 		spin_lock_bh(&iucv_table_lock);
1002 	rc = iucv_sever_pathid(path->pathid, userdata);
1003 	iucv_path_table[path->pathid] = NULL;
1004 	list_del_init(&path->list);
1005 	if (iucv_active_cpu != smp_processor_id())
1006 		spin_unlock_bh(&iucv_table_lock);
1007 out:
1008 	preempt_enable();
1009 	return rc;
1010 }
1011 EXPORT_SYMBOL(iucv_path_sever);
1012 
1013 /**
1014  * iucv_message_purge
1015  * @path: address of iucv path structure
1016  * @msg: address of iucv msg structure
1017  * @srccls: source class of message
1018  *
1019  * Cancels a message you have sent.
1020  *
1021  * Returns the result from the CP IUCV call.
1022  */
1023 int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg,
1024 		       u32 srccls)
1025 {
1026 	union iucv_param *parm;
1027 	int rc;
1028 
1029 	local_bh_disable();
1030 	if (cpumask_empty(&iucv_buffer_cpumask)) {
1031 		rc = -EIO;
1032 		goto out;
1033 	}
1034 	parm = iucv_param[smp_processor_id()];
1035 	memset(parm, 0, sizeof(union iucv_param));
1036 	parm->purge.ippathid = path->pathid;
1037 	parm->purge.ipmsgid = msg->id;
1038 	parm->purge.ipsrccls = srccls;
1039 	parm->purge.ipflags1 = IUCV_IPSRCCLS | IUCV_IPFGMID | IUCV_IPFGPID;
1040 	rc = iucv_call_b2f0(IUCV_PURGE, parm);
1041 	if (!rc) {
1042 		msg->audit = (*(u32 *) &parm->purge.ipaudit) >> 8;
1043 		msg->tag = parm->purge.ipmsgtag;
1044 	}
1045 out:
1046 	local_bh_enable();
1047 	return rc;
1048 }
1049 EXPORT_SYMBOL(iucv_message_purge);
1050 
1051 /**
1052  * iucv_message_receive_iprmdata
1053  * @path: address of iucv path structure
1054  * @msg: address of iucv msg structure
1055  * @flags: how the message is received (IUCV_IPBUFLST)
1056  * @buffer: address of data buffer or address of struct iucv_array
1057  * @size: length of data buffer
1058  * @residual:
1059  *
1060  * Internal function used by iucv_message_receive and __iucv_message_receive
1061  * to receive RMDATA data stored in struct iucv_message.
1062  */
1063 static int iucv_message_receive_iprmdata(struct iucv_path *path,
1064 					 struct iucv_message *msg,
1065 					 u8 flags, void *buffer,
1066 					 size_t size, size_t *residual)
1067 {
1068 	struct iucv_array *array;
1069 	u8 *rmmsg;
1070 	size_t copy;
1071 
1072 	/*
1073 	 * Message is 8 bytes long and has been stored to the
1074 	 * message descriptor itself.
1075 	 */
1076 	if (residual)
1077 		*residual = abs(size - 8);
1078 	rmmsg = msg->rmmsg;
1079 	if (flags & IUCV_IPBUFLST) {
1080 		/* Copy to struct iucv_array. */
1081 		size = (size < 8) ? size : 8;
1082 		for (array = buffer; size > 0; array++) {
1083 			copy = min_t(size_t, size, array->length);
1084 			memcpy(dma32_to_virt(array->address), rmmsg, copy);
1085 			rmmsg += copy;
1086 			size -= copy;
1087 		}
1088 	} else {
1089 		/* Copy to direct buffer. */
1090 		memcpy(buffer, rmmsg, min_t(size_t, size, 8));
1091 	}
1092 	return 0;
1093 }
1094 
1095 /**
1096  * __iucv_message_receive
1097  * @path: address of iucv path structure
1098  * @msg: address of iucv msg structure
1099  * @flags: how the message is received (IUCV_IPBUFLST)
1100  * @buffer: address of data buffer or address of struct iucv_array
1101  * @size: length of data buffer
1102  * @residual:
1103  *
1104  * This function receives messages that are being sent to you over
1105  * established paths. This function will deal with RMDATA messages
1106  * embedded in struct iucv_message as well.
1107  *
1108  * Locking:	no locking
1109  *
1110  * Returns the result from the CP IUCV call.
1111  */
1112 int __iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
1113 			   u8 flags, void *buffer, size_t size, size_t *residual)
1114 {
1115 	union iucv_param *parm;
1116 	int rc;
1117 
1118 	if (msg->flags & IUCV_IPRMDATA)
1119 		return iucv_message_receive_iprmdata(path, msg, flags,
1120 						     buffer, size, residual);
1121 	if (cpumask_empty(&iucv_buffer_cpumask))
1122 		return -EIO;
1123 
1124 	parm = iucv_param[smp_processor_id()];
1125 	memset(parm, 0, sizeof(union iucv_param));
1126 	parm->db.ipbfadr1 = virt_to_dma32(buffer);
1127 	parm->db.ipbfln1f = (u32) size;
1128 	parm->db.ipmsgid = msg->id;
1129 	parm->db.ippathid = path->pathid;
1130 	parm->db.iptrgcls = msg->class;
1131 	parm->db.ipflags1 = (flags | IUCV_IPFGPID |
1132 			     IUCV_IPFGMID | IUCV_IPTRGCLS);
1133 	rc = iucv_call_b2f0(IUCV_RECEIVE, parm);
1134 	if (!rc || rc == 5) {
1135 		msg->flags = parm->db.ipflags1;
1136 		if (residual)
1137 			*residual = parm->db.ipbfln1f;
1138 	}
1139 	return rc;
1140 }
1141 EXPORT_SYMBOL(__iucv_message_receive);
1142 
1143 /**
1144  * iucv_message_receive
1145  * @path: address of iucv path structure
1146  * @msg: address of iucv msg structure
1147  * @flags: how the message is received (IUCV_IPBUFLST)
1148  * @buffer: address of data buffer or address of struct iucv_array
1149  * @size: length of data buffer
1150  * @residual:
1151  *
1152  * This function receives messages that are being sent to you over
1153  * established paths. This function will deal with RMDATA messages
1154  * embedded in struct iucv_message as well.
1155  *
1156  * Locking:	local_bh_enable/local_bh_disable
1157  *
1158  * Returns the result from the CP IUCV call.
1159  */
1160 int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
1161 			 u8 flags, void *buffer, size_t size, size_t *residual)
1162 {
1163 	int rc;
1164 
1165 	if (msg->flags & IUCV_IPRMDATA)
1166 		return iucv_message_receive_iprmdata(path, msg, flags,
1167 						     buffer, size, residual);
1168 	local_bh_disable();
1169 	rc = __iucv_message_receive(path, msg, flags, buffer, size, residual);
1170 	local_bh_enable();
1171 	return rc;
1172 }
1173 EXPORT_SYMBOL(iucv_message_receive);
1174 
1175 /**
1176  * iucv_message_reject
1177  * @path: address of iucv path structure
1178  * @msg: address of iucv msg structure
1179  *
1180  * The reject function refuses a specified message. Between the time you
1181  * are notified of a message and the time that you complete the message,
1182  * the message may be rejected.
1183  *
1184  * Returns the result from the CP IUCV call.
1185  */
1186 int iucv_message_reject(struct iucv_path *path, struct iucv_message *msg)
1187 {
1188 	union iucv_param *parm;
1189 	int rc;
1190 
1191 	local_bh_disable();
1192 	if (cpumask_empty(&iucv_buffer_cpumask)) {
1193 		rc = -EIO;
1194 		goto out;
1195 	}
1196 	parm = iucv_param[smp_processor_id()];
1197 	memset(parm, 0, sizeof(union iucv_param));
1198 	parm->db.ippathid = path->pathid;
1199 	parm->db.ipmsgid = msg->id;
1200 	parm->db.iptrgcls = msg->class;
1201 	parm->db.ipflags1 = (IUCV_IPTRGCLS | IUCV_IPFGMID | IUCV_IPFGPID);
1202 	rc = iucv_call_b2f0(IUCV_REJECT, parm);
1203 out:
1204 	local_bh_enable();
1205 	return rc;
1206 }
1207 EXPORT_SYMBOL(iucv_message_reject);
1208 
1209 /**
1210  * iucv_message_reply
1211  * @path: address of iucv path structure
1212  * @msg: address of iucv msg structure
1213  * @flags: how the reply is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1214  * @reply: address of reply data buffer or address of struct iucv_array
1215  * @size: length of reply data buffer
1216  *
1217  * This function responds to the two-way messages that you receive. You
1218  * must identify completely the message to which you wish to reply. ie,
1219  * pathid, msgid, and trgcls. Prmmsg signifies the data is moved into
1220  * the parameter list.
1221  *
1222  * Returns the result from the CP IUCV call.
1223  */
1224 int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg,
1225 		       u8 flags, void *reply, size_t size)
1226 {
1227 	union iucv_param *parm;
1228 	int rc;
1229 
1230 	local_bh_disable();
1231 	if (cpumask_empty(&iucv_buffer_cpumask)) {
1232 		rc = -EIO;
1233 		goto out;
1234 	}
1235 	parm = iucv_param[smp_processor_id()];
1236 	memset(parm, 0, sizeof(union iucv_param));
1237 	if (flags & IUCV_IPRMDATA) {
1238 		parm->dpl.ippathid = path->pathid;
1239 		parm->dpl.ipflags1 = flags;
1240 		parm->dpl.ipmsgid = msg->id;
1241 		parm->dpl.iptrgcls = msg->class;
1242 		memcpy(parm->dpl.iprmmsg, reply, min_t(size_t, size, 8));
1243 	} else {
1244 		parm->db.ipbfadr1 = virt_to_dma32(reply);
1245 		parm->db.ipbfln1f = (u32) size;
1246 		parm->db.ippathid = path->pathid;
1247 		parm->db.ipflags1 = flags;
1248 		parm->db.ipmsgid = msg->id;
1249 		parm->db.iptrgcls = msg->class;
1250 	}
1251 	rc = iucv_call_b2f0(IUCV_REPLY, parm);
1252 out:
1253 	local_bh_enable();
1254 	return rc;
1255 }
1256 EXPORT_SYMBOL(iucv_message_reply);
1257 
1258 /**
1259  * __iucv_message_send
1260  * @path: address of iucv path structure
1261  * @msg: address of iucv msg structure
1262  * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1263  * @srccls: source class of message
1264  * @buffer: address of send buffer or address of struct iucv_array
1265  * @size: length of send buffer
1266  *
1267  * This function transmits data to another application. Data to be
1268  * transmitted is in a buffer and this is a one-way message and the
1269  * receiver will not reply to the message.
1270  *
1271  * Locking:	no locking
1272  *
1273  * Returns the result from the CP IUCV call.
1274  */
1275 int __iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
1276 		      u8 flags, u32 srccls, void *buffer, size_t size)
1277 {
1278 	union iucv_param *parm;
1279 	int rc;
1280 
1281 	if (cpumask_empty(&iucv_buffer_cpumask)) {
1282 		rc = -EIO;
1283 		goto out;
1284 	}
1285 	parm = iucv_param[smp_processor_id()];
1286 	memset(parm, 0, sizeof(union iucv_param));
1287 	if (flags & IUCV_IPRMDATA) {
1288 		/* Message of 8 bytes can be placed into the parameter list. */
1289 		parm->dpl.ippathid = path->pathid;
1290 		parm->dpl.ipflags1 = flags | IUCV_IPNORPY;
1291 		parm->dpl.iptrgcls = msg->class;
1292 		parm->dpl.ipsrccls = srccls;
1293 		parm->dpl.ipmsgtag = msg->tag;
1294 		memcpy(parm->dpl.iprmmsg, buffer, 8);
1295 	} else {
1296 		parm->db.ipbfadr1 = virt_to_dma32(buffer);
1297 		parm->db.ipbfln1f = (u32) size;
1298 		parm->db.ippathid = path->pathid;
1299 		parm->db.ipflags1 = flags | IUCV_IPNORPY;
1300 		parm->db.iptrgcls = msg->class;
1301 		parm->db.ipsrccls = srccls;
1302 		parm->db.ipmsgtag = msg->tag;
1303 	}
1304 	rc = iucv_call_b2f0(IUCV_SEND, parm);
1305 	if (!rc)
1306 		msg->id = parm->db.ipmsgid;
1307 out:
1308 	return rc;
1309 }
1310 EXPORT_SYMBOL(__iucv_message_send);
1311 
1312 /**
1313  * iucv_message_send
1314  * @path: address of iucv path structure
1315  * @msg: address of iucv msg structure
1316  * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1317  * @srccls: source class of message
1318  * @buffer: address of send buffer or address of struct iucv_array
1319  * @size: length of send buffer
1320  *
1321  * This function transmits data to another application. Data to be
1322  * transmitted is in a buffer and this is a one-way message and the
1323  * receiver will not reply to the message.
1324  *
1325  * Locking:	local_bh_enable/local_bh_disable
1326  *
1327  * Returns the result from the CP IUCV call.
1328  */
1329 int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
1330 		      u8 flags, u32 srccls, void *buffer, size_t size)
1331 {
1332 	int rc;
1333 
1334 	local_bh_disable();
1335 	rc = __iucv_message_send(path, msg, flags, srccls, buffer, size);
1336 	local_bh_enable();
1337 	return rc;
1338 }
1339 EXPORT_SYMBOL(iucv_message_send);
1340 
1341 /**
1342  * iucv_message_send2way
1343  * @path: address of iucv path structure
1344  * @msg: address of iucv msg structure
1345  * @flags: how the message is sent and the reply is received
1346  *	   (IUCV_IPRMDATA, IUCV_IPBUFLST, IUCV_IPPRTY, IUCV_ANSLST)
1347  * @srccls: source class of message
1348  * @buffer: address of send buffer or address of struct iucv_array
1349  * @size: length of send buffer
1350  * @answer: address of answer buffer or address of struct iucv_array
1351  * @asize: size of reply buffer
1352  * @residual: ignored
1353  *
1354  * This function transmits data to another application. Data to be
1355  * transmitted is in a buffer. The receiver of the send is expected to
1356  * reply to the message and a buffer is provided into which IUCV moves
1357  * the reply to this message.
1358  *
1359  * Returns the result from the CP IUCV call.
1360  */
1361 int iucv_message_send2way(struct iucv_path *path, struct iucv_message *msg,
1362 			  u8 flags, u32 srccls, void *buffer, size_t size,
1363 			  void *answer, size_t asize, size_t *residual)
1364 {
1365 	union iucv_param *parm;
1366 	int rc;
1367 
1368 	local_bh_disable();
1369 	if (cpumask_empty(&iucv_buffer_cpumask)) {
1370 		rc = -EIO;
1371 		goto out;
1372 	}
1373 	parm = iucv_param[smp_processor_id()];
1374 	memset(parm, 0, sizeof(union iucv_param));
1375 	if (flags & IUCV_IPRMDATA) {
1376 		parm->dpl.ippathid = path->pathid;
1377 		parm->dpl.ipflags1 = path->flags;	/* priority message */
1378 		parm->dpl.iptrgcls = msg->class;
1379 		parm->dpl.ipsrccls = srccls;
1380 		parm->dpl.ipmsgtag = msg->tag;
1381 		parm->dpl.ipbfadr2 = virt_to_dma32(answer);
1382 		parm->dpl.ipbfln2f = (u32) asize;
1383 		memcpy(parm->dpl.iprmmsg, buffer, 8);
1384 	} else {
1385 		parm->db.ippathid = path->pathid;
1386 		parm->db.ipflags1 = path->flags;	/* priority message */
1387 		parm->db.iptrgcls = msg->class;
1388 		parm->db.ipsrccls = srccls;
1389 		parm->db.ipmsgtag = msg->tag;
1390 		parm->db.ipbfadr1 = virt_to_dma32(buffer);
1391 		parm->db.ipbfln1f = (u32) size;
1392 		parm->db.ipbfadr2 = virt_to_dma32(answer);
1393 		parm->db.ipbfln2f = (u32) asize;
1394 	}
1395 	rc = iucv_call_b2f0(IUCV_SEND, parm);
1396 	if (!rc)
1397 		msg->id = parm->db.ipmsgid;
1398 out:
1399 	local_bh_enable();
1400 	return rc;
1401 }
1402 EXPORT_SYMBOL(iucv_message_send2way);
1403 
1404 struct iucv_path_pending {
1405 	u16 ippathid;
1406 	u8  ipflags1;
1407 	u8  iptype;
1408 	u16 ipmsglim;
1409 	u16 res1;
1410 	u8  ipvmid[8];
1411 	u8  ipuser[16];
1412 	u32 res3;
1413 	u8  ippollfg;
1414 	u8  res4[3];
1415 } __packed;
1416 
1417 /**
1418  * iucv_path_pending
1419  * @data: Pointer to external interrupt buffer
1420  *
1421  * Process connection pending work item. Called from tasklet while holding
1422  * iucv_table_lock.
1423  */
1424 static void iucv_path_pending(struct iucv_irq_data *data)
1425 {
1426 	struct iucv_path_pending *ipp = (void *) data;
1427 	struct iucv_handler *handler;
1428 	struct iucv_path *path;
1429 	char *error;
1430 
1431 	BUG_ON(iucv_path_table[ipp->ippathid]);
1432 	/* New pathid, handler found. Create a new path struct. */
1433 	error = iucv_error_no_memory;
1434 	path = iucv_path_alloc(ipp->ipmsglim, ipp->ipflags1, GFP_ATOMIC);
1435 	if (!path)
1436 		goto out_sever;
1437 	path->pathid = ipp->ippathid;
1438 	iucv_path_table[path->pathid] = path;
1439 	EBCASC(ipp->ipvmid, 8);
1440 
1441 	/* Call registered handler until one is found that wants the path. */
1442 	list_for_each_entry(handler, &iucv_handler_list, list) {
1443 		if (!handler->path_pending)
1444 			continue;
1445 		/*
1446 		 * Add path to handler to allow a call to iucv_path_sever
1447 		 * inside the path_pending function. If the handler returns
1448 		 * an error remove the path from the handler again.
1449 		 */
1450 		list_add(&path->list, &handler->paths);
1451 		path->handler = handler;
1452 		if (!handler->path_pending(path, ipp->ipvmid, ipp->ipuser))
1453 			return;
1454 		list_del(&path->list);
1455 		path->handler = NULL;
1456 	}
1457 	/* No handler wanted the path. */
1458 	iucv_path_table[path->pathid] = NULL;
1459 	iucv_path_free(path);
1460 	error = iucv_error_no_listener;
1461 out_sever:
1462 	iucv_sever_pathid(ipp->ippathid, error);
1463 }
1464 
1465 struct iucv_path_complete {
1466 	u16 ippathid;
1467 	u8  ipflags1;
1468 	u8  iptype;
1469 	u16 ipmsglim;
1470 	u16 res1;
1471 	u8  res2[8];
1472 	u8  ipuser[16];
1473 	u32 res3;
1474 	u8  ippollfg;
1475 	u8  res4[3];
1476 } __packed;
1477 
1478 /**
1479  * iucv_path_complete
1480  * @data: Pointer to external interrupt buffer
1481  *
1482  * Process connection complete work item. Called from tasklet while holding
1483  * iucv_table_lock.
1484  */
1485 static void iucv_path_complete(struct iucv_irq_data *data)
1486 {
1487 	struct iucv_path_complete *ipc = (void *) data;
1488 	struct iucv_path *path = iucv_path_table[ipc->ippathid];
1489 
1490 	if (path)
1491 		path->flags = ipc->ipflags1;
1492 	if (path && path->handler && path->handler->path_complete)
1493 		path->handler->path_complete(path, ipc->ipuser);
1494 }
1495 
1496 struct iucv_path_severed {
1497 	u16 ippathid;
1498 	u8  res1;
1499 	u8  iptype;
1500 	u32 res2;
1501 	u8  res3[8];
1502 	u8  ipuser[16];
1503 	u32 res4;
1504 	u8  ippollfg;
1505 	u8  res5[3];
1506 } __packed;
1507 
1508 /**
1509  * iucv_path_severed
1510  * @data: Pointer to external interrupt buffer
1511  *
1512  * Process connection severed work item. Called from tasklet while holding
1513  * iucv_table_lock.
1514  */
1515 static void iucv_path_severed(struct iucv_irq_data *data)
1516 {
1517 	struct iucv_path_severed *ips = (void *) data;
1518 	struct iucv_path *path = iucv_path_table[ips->ippathid];
1519 
1520 	if (!path || !path->handler)	/* Already severed */
1521 		return;
1522 	if (path->handler->path_severed)
1523 		path->handler->path_severed(path, ips->ipuser);
1524 	else {
1525 		iucv_sever_pathid(path->pathid, NULL);
1526 		iucv_path_table[path->pathid] = NULL;
1527 		list_del(&path->list);
1528 		iucv_path_free(path);
1529 	}
1530 }
1531 
1532 struct iucv_path_quiesced {
1533 	u16 ippathid;
1534 	u8  res1;
1535 	u8  iptype;
1536 	u32 res2;
1537 	u8  res3[8];
1538 	u8  ipuser[16];
1539 	u32 res4;
1540 	u8  ippollfg;
1541 	u8  res5[3];
1542 } __packed;
1543 
1544 /**
1545  * iucv_path_quiesced
1546  * @data: Pointer to external interrupt buffer
1547  *
1548  * Process connection quiesced work item. Called from tasklet while holding
1549  * iucv_table_lock.
1550  */
1551 static void iucv_path_quiesced(struct iucv_irq_data *data)
1552 {
1553 	struct iucv_path_quiesced *ipq = (void *) data;
1554 	struct iucv_path *path = iucv_path_table[ipq->ippathid];
1555 
1556 	if (path && path->handler && path->handler->path_quiesced)
1557 		path->handler->path_quiesced(path, ipq->ipuser);
1558 }
1559 
1560 struct iucv_path_resumed {
1561 	u16 ippathid;
1562 	u8  res1;
1563 	u8  iptype;
1564 	u32 res2;
1565 	u8  res3[8];
1566 	u8  ipuser[16];
1567 	u32 res4;
1568 	u8  ippollfg;
1569 	u8  res5[3];
1570 } __packed;
1571 
1572 /**
1573  * iucv_path_resumed
1574  * @data: Pointer to external interrupt buffer
1575  *
1576  * Process connection resumed work item. Called from tasklet while holding
1577  * iucv_table_lock.
1578  */
1579 static void iucv_path_resumed(struct iucv_irq_data *data)
1580 {
1581 	struct iucv_path_resumed *ipr = (void *) data;
1582 	struct iucv_path *path = iucv_path_table[ipr->ippathid];
1583 
1584 	if (path && path->handler && path->handler->path_resumed)
1585 		path->handler->path_resumed(path, ipr->ipuser);
1586 }
1587 
1588 struct iucv_message_complete {
1589 	u16 ippathid;
1590 	u8  ipflags1;
1591 	u8  iptype;
1592 	u32 ipmsgid;
1593 	u32 ipaudit;
1594 	u8  iprmmsg[8];
1595 	u32 ipsrccls;
1596 	u32 ipmsgtag;
1597 	u32 res;
1598 	u32 ipbfln2f;
1599 	u8  ippollfg;
1600 	u8  res2[3];
1601 } __packed;
1602 
1603 /**
1604  * iucv_message_complete
1605  * @data: Pointer to external interrupt buffer
1606  *
1607  * Process message complete work item. Called from tasklet while holding
1608  * iucv_table_lock.
1609  */
1610 static void iucv_message_complete(struct iucv_irq_data *data)
1611 {
1612 	struct iucv_message_complete *imc = (void *) data;
1613 	struct iucv_path *path = iucv_path_table[imc->ippathid];
1614 	struct iucv_message msg;
1615 
1616 	if (path && path->handler && path->handler->message_complete) {
1617 		msg.flags = imc->ipflags1;
1618 		msg.id = imc->ipmsgid;
1619 		msg.audit = imc->ipaudit;
1620 		memcpy(msg.rmmsg, imc->iprmmsg, 8);
1621 		msg.class = imc->ipsrccls;
1622 		msg.tag = imc->ipmsgtag;
1623 		msg.length = imc->ipbfln2f;
1624 		path->handler->message_complete(path, &msg);
1625 	}
1626 }
1627 
1628 struct iucv_message_pending {
1629 	u16 ippathid;
1630 	u8  ipflags1;
1631 	u8  iptype;
1632 	u32 ipmsgid;
1633 	u32 iptrgcls;
1634 	struct {
1635 		union {
1636 			u32 iprmmsg1_u32;
1637 			u8  iprmmsg1[4];
1638 		} ln1msg1;
1639 		union {
1640 			u32 ipbfln1f;
1641 			u8  iprmmsg2[4];
1642 		} ln1msg2;
1643 	} rmmsg;
1644 	u32 res1[3];
1645 	u32 ipbfln2f;
1646 	u8  ippollfg;
1647 	u8  res2[3];
1648 } __packed;
1649 
1650 /**
1651  * iucv_message_pending
1652  * @data: Pointer to external interrupt buffer
1653  *
1654  * Process message pending work item. Called from tasklet while holding
1655  * iucv_table_lock.
1656  */
1657 static void iucv_message_pending(struct iucv_irq_data *data)
1658 {
1659 	struct iucv_message_pending *imp = (void *) data;
1660 	struct iucv_path *path = iucv_path_table[imp->ippathid];
1661 	struct iucv_message msg;
1662 
1663 	if (path && path->handler && path->handler->message_pending) {
1664 		msg.flags = imp->ipflags1;
1665 		msg.id = imp->ipmsgid;
1666 		msg.class = imp->iptrgcls;
1667 		if (imp->ipflags1 & IUCV_IPRMDATA) {
1668 			memcpy(msg.rmmsg, &imp->rmmsg, 8);
1669 			msg.length = 8;
1670 		} else
1671 			msg.length = imp->rmmsg.ln1msg2.ipbfln1f;
1672 		msg.reply_size = imp->ipbfln2f;
1673 		path->handler->message_pending(path, &msg);
1674 	}
1675 }
1676 
1677 /*
1678  * iucv_tasklet_fn:
1679  *
1680  * This tasklet loops over the queue of irq buffers created by
1681  * iucv_external_interrupt, calls the appropriate action handler
1682  * and then frees the buffer.
1683  */
1684 static void iucv_tasklet_fn(unsigned long ignored)
1685 {
1686 	typedef void iucv_irq_fn(struct iucv_irq_data *);
1687 	static iucv_irq_fn *irq_fn[] = {
1688 		[0x02] = iucv_path_complete,
1689 		[0x03] = iucv_path_severed,
1690 		[0x04] = iucv_path_quiesced,
1691 		[0x05] = iucv_path_resumed,
1692 		[0x06] = iucv_message_complete,
1693 		[0x07] = iucv_message_complete,
1694 		[0x08] = iucv_message_pending,
1695 		[0x09] = iucv_message_pending,
1696 	};
1697 	LIST_HEAD(task_queue);
1698 	struct iucv_irq_list *p, *n;
1699 
1700 	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */
1701 	if (!spin_trylock(&iucv_table_lock)) {
1702 		tasklet_schedule(&iucv_tasklet);
1703 		return;
1704 	}
1705 	iucv_active_cpu = smp_processor_id();
1706 
1707 	spin_lock_irq(&iucv_queue_lock);
1708 	list_splice_init(&iucv_task_queue, &task_queue);
1709 	spin_unlock_irq(&iucv_queue_lock);
1710 
1711 	list_for_each_entry_safe(p, n, &task_queue, list) {
1712 		list_del_init(&p->list);
1713 		irq_fn[p->data.iptype](&p->data);
1714 		kfree(p);
1715 	}
1716 
1717 	iucv_active_cpu = -1;
1718 	spin_unlock(&iucv_table_lock);
1719 }
1720 
1721 /*
1722  * iucv_work_fn:
1723  *
1724  * This work function loops over the queue of path pending irq blocks
1725  * created by iucv_external_interrupt, calls the appropriate action
1726  * handler and then frees the buffer.
1727  */
1728 static void iucv_work_fn(struct work_struct *work)
1729 {
1730 	LIST_HEAD(work_queue);
1731 	struct iucv_irq_list *p, *n;
1732 
1733 	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */
1734 	spin_lock_bh(&iucv_table_lock);
1735 	iucv_active_cpu = smp_processor_id();
1736 
1737 	spin_lock_irq(&iucv_queue_lock);
1738 	list_splice_init(&iucv_work_queue, &work_queue);
1739 	spin_unlock_irq(&iucv_queue_lock);
1740 
1741 	iucv_cleanup_queue();
1742 	list_for_each_entry_safe(p, n, &work_queue, list) {
1743 		list_del_init(&p->list);
1744 		iucv_path_pending(&p->data);
1745 		kfree(p);
1746 	}
1747 
1748 	iucv_active_cpu = -1;
1749 	spin_unlock_bh(&iucv_table_lock);
1750 }
1751 
1752 /*
1753  * iucv_external_interrupt
1754  *
1755  * Handles external interrupts coming in from CP.
1756  * Places the interrupt buffer on a queue and schedules iucv_tasklet_fn().
1757  */
1758 static void iucv_external_interrupt(struct ext_code ext_code,
1759 				    unsigned int param32, unsigned long param64)
1760 {
1761 	struct iucv_irq_data *p;
1762 	struct iucv_irq_list *work;
1763 
1764 	inc_irq_stat(IRQEXT_IUC);
1765 	p = iucv_irq_data[smp_processor_id()];
1766 	if (p->ippathid >= iucv_max_pathid) {
1767 		WARN_ON(p->ippathid >= iucv_max_pathid);
1768 		iucv_sever_pathid(p->ippathid, iucv_error_no_listener);
1769 		return;
1770 	}
1771 	BUG_ON(p->iptype  < 0x01 || p->iptype > 0x09);
1772 	work = kmalloc(sizeof(struct iucv_irq_list), GFP_ATOMIC);
1773 	if (!work) {
1774 		pr_warn("iucv_external_interrupt: out of memory\n");
1775 		return;
1776 	}
1777 	memcpy(&work->data, p, sizeof(work->data));
1778 	spin_lock(&iucv_queue_lock);
1779 	if (p->iptype == 0x01) {
1780 		/* Path pending interrupt. */
1781 		list_add_tail(&work->list, &iucv_work_queue);
1782 		schedule_work(&iucv_work);
1783 	} else {
1784 		/* The other interrupts. */
1785 		list_add_tail(&work->list, &iucv_task_queue);
1786 		tasklet_schedule(&iucv_tasklet);
1787 	}
1788 	spin_unlock(&iucv_queue_lock);
1789 }
1790 
1791 struct iucv_interface iucv_if = {
1792 	.message_receive = iucv_message_receive,
1793 	.__message_receive = __iucv_message_receive,
1794 	.message_reply = iucv_message_reply,
1795 	.message_reject = iucv_message_reject,
1796 	.message_send = iucv_message_send,
1797 	.__message_send = __iucv_message_send,
1798 	.message_send2way = iucv_message_send2way,
1799 	.message_purge = iucv_message_purge,
1800 	.path_accept = iucv_path_accept,
1801 	.path_connect = iucv_path_connect,
1802 	.path_quiesce = iucv_path_quiesce,
1803 	.path_resume = iucv_path_resume,
1804 	.path_sever = iucv_path_sever,
1805 	.iucv_register = iucv_register,
1806 	.iucv_unregister = iucv_unregister,
1807 	.bus = NULL,
1808 	.root = NULL,
1809 };
1810 EXPORT_SYMBOL(iucv_if);
1811 
1812 static enum cpuhp_state iucv_online;
1813 /**
1814  * iucv_init
1815  *
1816  * Allocates and initializes various data structures.
1817  */
1818 static int __init iucv_init(void)
1819 {
1820 	int rc;
1821 
1822 	if (!MACHINE_IS_VM) {
1823 		rc = -EPROTONOSUPPORT;
1824 		goto out;
1825 	}
1826 	system_ctl_set_bit(0, CR0_IUCV_BIT);
1827 	rc = iucv_query_maxconn();
1828 	if (rc)
1829 		goto out_ctl;
1830 	rc = register_external_irq(EXT_IRQ_IUCV, iucv_external_interrupt);
1831 	if (rc)
1832 		goto out_ctl;
1833 	iucv_root = root_device_register("iucv");
1834 	if (IS_ERR(iucv_root)) {
1835 		rc = PTR_ERR(iucv_root);
1836 		goto out_int;
1837 	}
1838 
1839 	rc = cpuhp_setup_state(CPUHP_NET_IUCV_PREPARE, "net/iucv:prepare",
1840 			       iucv_cpu_prepare, iucv_cpu_dead);
1841 	if (rc)
1842 		goto out_dev;
1843 	rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "net/iucv:online",
1844 			       iucv_cpu_online, iucv_cpu_down_prep);
1845 	if (rc < 0)
1846 		goto out_prep;
1847 	iucv_online = rc;
1848 
1849 	rc = register_reboot_notifier(&iucv_reboot_notifier);
1850 	if (rc)
1851 		goto out_remove_hp;
1852 	ASCEBC(iucv_error_no_listener, 16);
1853 	ASCEBC(iucv_error_no_memory, 16);
1854 	ASCEBC(iucv_error_pathid, 16);
1855 	iucv_available = 1;
1856 	rc = bus_register(&iucv_bus);
1857 	if (rc)
1858 		goto out_reboot;
1859 	iucv_if.root = iucv_root;
1860 	iucv_if.bus = &iucv_bus;
1861 	return 0;
1862 
1863 out_reboot:
1864 	unregister_reboot_notifier(&iucv_reboot_notifier);
1865 out_remove_hp:
1866 	cpuhp_remove_state(iucv_online);
1867 out_prep:
1868 	cpuhp_remove_state(CPUHP_NET_IUCV_PREPARE);
1869 out_dev:
1870 	root_device_unregister(iucv_root);
1871 out_int:
1872 	unregister_external_irq(EXT_IRQ_IUCV, iucv_external_interrupt);
1873 out_ctl:
1874 	system_ctl_clear_bit(0, 1);
1875 out:
1876 	return rc;
1877 }
1878 
1879 /**
1880  * iucv_exit
1881  *
1882  * Frees everything allocated from iucv_init.
1883  */
1884 static void __exit iucv_exit(void)
1885 {
1886 	struct iucv_irq_list *p, *n;
1887 
1888 	spin_lock_irq(&iucv_queue_lock);
1889 	list_for_each_entry_safe(p, n, &iucv_task_queue, list)
1890 		kfree(p);
1891 	list_for_each_entry_safe(p, n, &iucv_work_queue, list)
1892 		kfree(p);
1893 	spin_unlock_irq(&iucv_queue_lock);
1894 	unregister_reboot_notifier(&iucv_reboot_notifier);
1895 
1896 	cpuhp_remove_state_nocalls(iucv_online);
1897 	cpuhp_remove_state(CPUHP_NET_IUCV_PREPARE);
1898 	root_device_unregister(iucv_root);
1899 	bus_unregister(&iucv_bus);
1900 	unregister_external_irq(EXT_IRQ_IUCV, iucv_external_interrupt);
1901 }
1902 
1903 subsys_initcall(iucv_init);
1904 module_exit(iucv_exit);
1905 
1906 MODULE_AUTHOR("(C) 2001 IBM Corp. by Fritz Elfert <felfert@millenux.com>");
1907 MODULE_DESCRIPTION("Linux for S/390 IUCV lowlevel driver");
1908 MODULE_LICENSE("GPL");
1909