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 pr_fmt(fmt) "iucv: " fmt
24
25	#include <linux/kernel_stat.h>
26	#include <linux/export.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/machine.h>
43	#include <asm/ebcdic.h>
44	#include <asm/io.h>
45	#include <asm/irq.h>
46	#include <asm/smp.h>
47
48	/*
49	* FLAGS:
50	* All flags are defined in the field IPFLAGS1 of each function
51	* and can be found in CP Programming Services.
52	* IPSRCCLS - Indicates you have specified a source class.
53	* IPTRGCLS - Indicates you have specified a target class.
54	* IPFGPID - Indicates you have specified a pathid.
55	* IPFGMID - Indicates you have specified a message ID.
56	* IPNORPY - Indicates a one-way message. No reply expected.
57	* IPALL - Indicates that all paths are affected.
58	*/
59	#define IUCV_IPSRCCLS 0x01
60	#define IUCV_IPTRGCLS 0x01
61	#define IUCV_IPFGPID 0x02
62	#define IUCV_IPFGMID 0x04
63	#define IUCV_IPNORPY 0x10
64	#define IUCV_IPALL 0x80
65
66	static int iucv_bus_match(struct device *dev, const struct device_driver *drv)
67	{
68	return 0;
69	}
70
71	const struct bus_type iucv_bus = {
72	.name = "iucv",
73	.match = iucv_bus_match,
74	};
75	EXPORT_SYMBOL(iucv_bus);
76
77	static struct device *iucv_root;
78
79	static void iucv_release_device(struct device *device)
80	{
81	kfree(objp: device);
82	}
83
84	struct device *iucv_alloc_device(const struct attribute_group **attrs,
85	struct device_driver *driver,
86	void *priv, const char *fmt, ...)
87	{
88	struct device *dev;
89	va_list vargs;
90	char buf[20];
91	int rc;
92
93	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
94	if (!dev)
95	goto out_error;
96	va_start(vargs, fmt);
97	vscnprintf(buf, size: sizeof(buf), fmt, args: vargs);
98	rc = dev_set_name(dev, name: "%s", buf);
99	va_end(vargs);
100	if (rc)
101	goto out_error;
102	dev->bus = &iucv_bus;
103	dev->parent = iucv_root;
104	dev->driver = driver;
105	dev->groups = attrs;
106	dev->release = iucv_release_device;
107	dev_set_drvdata(dev, data: priv);
108	return dev;
109
110	out_error:
111	kfree(objp: dev);
112	return NULL;
113	}
114	EXPORT_SYMBOL(iucv_alloc_device);
115
116	static int iucv_available;
117
118	/* General IUCV interrupt structure */
119	struct iucv_irq_data {
120	u16 ippathid;
121	u8 ipflags1;
122	u8 iptype;
123	u32 res2[9];
124	};
125
126	struct iucv_irq_list {
127	struct list_head list;
128	struct iucv_irq_data data;
129	};
130
131	static struct iucv_irq_data *iucv_irq_data[NR_CPUS];
132	static cpumask_t iucv_buffer_cpumask = { CPU_BITS_NONE };
133	static cpumask_t iucv_irq_cpumask = { CPU_BITS_NONE };
134
135	/*
136	* Queue of interrupt buffers lock for delivery via the tasklet
137	* (fast but can't call smp_call_function).
138	*/
139	static LIST_HEAD(iucv_task_queue);
140
141	/*
142	* The tasklet for fast delivery of iucv interrupts.
143	*/
144	static void iucv_tasklet_fn(unsigned long);
145	static DECLARE_TASKLET_OLD(iucv_tasklet, iucv_tasklet_fn);
146
147	/*
148	* Queue of interrupt buffers for delivery via a work queue
149	* (slower but can call smp_call_function).
150	*/
151	static LIST_HEAD(iucv_work_queue);
152
153	/*
154	* The work element to deliver path pending interrupts.
155	*/
156	static void iucv_work_fn(struct work_struct *work);
157	static DECLARE_WORK(iucv_work, iucv_work_fn);
158
159	/*
160	* Spinlock protecting task and work queue.
161	*/
162	static DEFINE_SPINLOCK(iucv_queue_lock);
163
164	enum iucv_command_codes {
165	IUCV_QUERY = 0,
166	IUCV_RETRIEVE_BUFFER = 2,
167	IUCV_SEND = 4,
168	IUCV_RECEIVE = 5,
169	IUCV_REPLY = 6,
170	IUCV_REJECT = 8,
171	IUCV_PURGE = 9,
172	IUCV_ACCEPT = 10,
173	IUCV_CONNECT = 11,
174	IUCV_DECLARE_BUFFER = 12,
175	IUCV_QUIESCE = 13,
176	IUCV_RESUME = 14,
177	IUCV_SEVER = 15,
178	IUCV_SETMASK = 16,
179	IUCV_SETCONTROLMASK = 17,
180	};
181
182	/*
183	* Error messages that are used with the iucv_sever function. They get
184	* converted to EBCDIC.
185	*/
186	static char iucv_error_no_listener[16] = "NO LISTENER";
187	static char iucv_error_no_memory[16] = "NO MEMORY";
188	static char iucv_error_pathid[16] = "INVALID PATHID";
189
190	/*
191	* iucv_handler_list: List of registered handlers.
192	*/
193	static LIST_HEAD(iucv_handler_list);
194
195	/*
196	* iucv_path_table: array of pointers to iucv_path structures.
197	*/
198	static struct iucv_path **iucv_path_table;
199	static unsigned long iucv_max_pathid;
200
201	/*
202	* iucv_lock: spinlock protecting iucv_handler_list and iucv_pathid_table
203	*/
204	static DEFINE_SPINLOCK(iucv_table_lock);
205
206	/*
207	* iucv_active_cpu: contains the number of the cpu executing the tasklet
208	* or the work handler. Needed for iucv_path_sever called from tasklet.
209	*/
210	static int iucv_active_cpu = -1;
211
212	/*
213	* Mutex and wait queue for iucv_register/iucv_unregister.
214	*/
215	static DEFINE_MUTEX(iucv_register_mutex);
216
217	/*
218	* Counter for number of non-smp capable handlers.
219	*/
220	static int iucv_nonsmp_handler;
221
222	/*
223	* IUCV control data structure. Used by iucv_path_accept, iucv_path_connect,
224	* iucv_path_quiesce and iucv_path_sever.
225	*/
226	struct iucv_cmd_control {
227	u16 ippathid;
228	u8 ipflags1;
229	u8 iprcode;
230	u16 ipmsglim;
231	u16 res1;
232	u8 ipvmid[8];
233	u8 ipuser[16];
234	u8 iptarget[8];
235	} __attribute__ ((packed,aligned(8)));
236
237	/*
238	* Data in parameter list iucv structure. Used by iucv_message_send,
239	* iucv_message_send2way and iucv_message_reply.
240	*/
241	struct iucv_cmd_dpl {
242	u16 ippathid;
243	u8 ipflags1;
244	u8 iprcode;
245	u32 ipmsgid;
246	u32 iptrgcls;
247	u8 iprmmsg[8];
248	u32 ipsrccls;
249	u32 ipmsgtag;
250	dma32_t ipbfadr2;
251	u32 ipbfln2f;
252	u32 res;
253	} __attribute__ ((packed,aligned(8)));
254
255	/*
256	* Data in buffer iucv structure. Used by iucv_message_receive,
257	* iucv_message_reject, iucv_message_send, iucv_message_send2way
258	* and iucv_declare_cpu.
259	*/
260	struct iucv_cmd_db {
261	u16 ippathid;
262	u8 ipflags1;
263	u8 iprcode;
264	u32 ipmsgid;
265	u32 iptrgcls;
266	dma32_t ipbfadr1;
267	u32 ipbfln1f;
268	u32 ipsrccls;
269	u32 ipmsgtag;
270	dma32_t ipbfadr2;
271	u32 ipbfln2f;
272	u32 res;
273	} __attribute__ ((packed,aligned(8)));
274
275	/*
276	* Purge message iucv structure. Used by iucv_message_purge.
277	*/
278	struct iucv_cmd_purge {
279	u16 ippathid;
280	u8 ipflags1;
281	u8 iprcode;
282	u32 ipmsgid;
283	u8 ipaudit[3];
284	u8 res1[5];
285	u32 res2;
286	u32 ipsrccls;
287	u32 ipmsgtag;
288	u32 res3[3];
289	} __attribute__ ((packed,aligned(8)));
290
291	/*
292	* Set mask iucv structure. Used by iucv_enable_cpu.
293	*/
294	struct iucv_cmd_set_mask {
295	u8 ipmask;
296	u8 res1[2];
297	u8 iprcode;
298	u32 res2[9];
299	} __attribute__ ((packed,aligned(8)));
300
301	union iucv_param {
302	struct iucv_cmd_control ctrl;
303	struct iucv_cmd_dpl dpl;
304	struct iucv_cmd_db db;
305	struct iucv_cmd_purge purge;
306	struct iucv_cmd_set_mask set_mask;
307	};
308
309	/*
310	* Anchor for per-cpu IUCV command parameter block.
311	*/
312	static union iucv_param *iucv_param[NR_CPUS];
313	static union iucv_param *iucv_param_irq[NR_CPUS];
314
315	/**
316	* __iucv_call_b2f0
317	* @command: identifier of IUCV call to CP.
318	* @parm: pointer to a struct iucv_parm block
319	*
320	* Calls CP to execute IUCV commands.
321	*
322	* Returns the result of the CP IUCV call.
323	*/
324	static inline int __iucv_call_b2f0(int command, union iucv_param *parm)
325	{
326	unsigned long reg1 = virt_to_phys(address: parm);
327	int cc;
328
329	asm volatile(
330	" lgr 0,%[reg0]\n"
331	" lgr 1,%[reg1]\n"
332	" .long 0xb2f01000\n"
333	" ipm %[cc]\n"
334	" srl %[cc],28\n"
335	: [cc] "=&d" (cc), "+m" (*parm)
336	: [reg0] "d" ((unsigned long)command),
337	[reg1] "d" (reg1)
338	: "cc", "0", "1");
339	return cc;
340	}
341
342	static inline int iucv_call_b2f0(int command, union iucv_param *parm)
343	{
344	int ccode;
345
346	ccode = __iucv_call_b2f0(command, parm);
347	return ccode == 1 ? parm->ctrl.iprcode : ccode;
348	}
349
350	/*
351	* iucv_query_maxconn
352	*
353	* Determines the maximum number of connections that may be established.
354	*
355	* Returns the maximum number of connections or -EPERM is IUCV is not
356	* available.
357	*/
358	static int __iucv_query_maxconn(void *param, unsigned long *max_pathid)
359	{
360	unsigned long reg1 = virt_to_phys(address: param);
361	int cc;
362
363	asm volatile (
364	" lghi 0,%[cmd]\n"
365	" lgr 1,%[reg1]\n"
366	" .long 0xb2f01000\n"
367	" ipm %[cc]\n"
368	" srl %[cc],28\n"
369	" lgr %[reg1],1\n"
370	: [cc] "=&d" (cc), [reg1] "+&d" (reg1)
371	: [cmd] "K" (IUCV_QUERY)
372	: "cc", "0", "1");
373	*max_pathid = reg1;
374	return cc;
375	}
376
377	static int iucv_query_maxconn(void)
378	{
379	unsigned long max_pathid;
380	void *param;
381	int ccode;
382
383	param = kzalloc(sizeof(union iucv_param), GFP_KERNEL | GFP_DMA);
384	if (!param)
385	return -ENOMEM;
386	ccode = __iucv_query_maxconn(param, max_pathid: &max_pathid);
387	if (ccode == 0)
388	iucv_max_pathid = max_pathid;
389	kfree(objp: param);
390	return ccode ? -EPERM : 0;
391	}
392
393	/**
394	* iucv_allow_cpu
395	* @data: unused
396	*
397	* Allow iucv interrupts on this cpu.
398	*/
399	static void iucv_allow_cpu(void *data)
400	{
401	int cpu = smp_processor_id();
402	union iucv_param *parm;
403
404	/*
405	* Enable all iucv interrupts.
406	* ipmask contains bits for the different interrupts
407	* 0x80 - Flag to allow nonpriority message pending interrupts
408	* 0x40 - Flag to allow priority message pending interrupts
409	* 0x20 - Flag to allow nonpriority message completion interrupts
410	* 0x10 - Flag to allow priority message completion interrupts
411	* 0x08 - Flag to allow IUCV control interrupts
412	*/
413	parm = iucv_param_irq[cpu];
414	memset(parm, 0, sizeof(union iucv_param));
415	parm->set_mask.ipmask = 0xf8;
416	iucv_call_b2f0(command: IUCV_SETMASK, parm);
417
418	/*
419	* Enable all iucv control interrupts.
420	* ipmask contains bits for the different interrupts
421	* 0x80 - Flag to allow pending connections interrupts
422	* 0x40 - Flag to allow connection complete interrupts
423	* 0x20 - Flag to allow connection severed interrupts
424	* 0x10 - Flag to allow connection quiesced interrupts
425	* 0x08 - Flag to allow connection resumed interrupts
426	*/
427	memset(parm, 0, sizeof(union iucv_param));
428	parm->set_mask.ipmask = 0xf8;
429	iucv_call_b2f0(command: IUCV_SETCONTROLMASK, parm);
430	/* Set indication that iucv interrupts are allowed for this cpu. */
431	cpumask_set_cpu(cpu, dstp: &iucv_irq_cpumask);
432	}
433
434	/**
435	* iucv_block_cpu
436	* @data: unused
437	*
438	* Block iucv interrupts on this cpu.
439	*/
440	static void iucv_block_cpu(void *data)
441	{
442	int cpu = smp_processor_id();
443	union iucv_param *parm;
444
445	/* Disable all iucv interrupts. */
446	parm = iucv_param_irq[cpu];
447	memset(parm, 0, sizeof(union iucv_param));
448	iucv_call_b2f0(command: IUCV_SETMASK, parm);
449
450	/* Clear indication that iucv interrupts are allowed for this cpu. */
451	cpumask_clear_cpu(cpu, dstp: &iucv_irq_cpumask);
452	}
453
454	/**
455	* iucv_declare_cpu
456	* @data: unused
457	*
458	* Declare a interrupt buffer on this cpu.
459	*/
460	static void iucv_declare_cpu(void *data)
461	{
462	int cpu = smp_processor_id();
463	union iucv_param *parm;
464	int rc;
465
466	if (cpumask_test_cpu(cpu, cpumask: &iucv_buffer_cpumask))
467	return;
468
469	/* Declare interrupt buffer. */
470	parm = iucv_param_irq[cpu];
471	memset(parm, 0, sizeof(union iucv_param));
472	parm->db.ipbfadr1 = virt_to_dma32(iucv_irq_data[cpu]);
473	rc = iucv_call_b2f0(command: IUCV_DECLARE_BUFFER, parm);
474	if (rc) {
475	char *err = "Unknown";
476	switch (rc) {
477	case 0x03:
478	err = "Directory error";
479	break;
480	case 0x0a:
481	err = "Invalid length";
482	break;
483	case 0x13:
484	err = "Buffer already exists";
485	break;
486	case 0x3e:
487	err = "Buffer overlap";
488	break;
489	case 0x5c:
490	err = "Paging or storage error";
491	break;
492	}
493	pr_warn("Defining an interrupt buffer on CPU %i failed with 0x%02x (%s)\n",
494	cpu, rc, err);
495	return;
496	}
497
498	/* Set indication that an iucv buffer exists for this cpu. */
499	cpumask_set_cpu(cpu, dstp: &iucv_buffer_cpumask);
500
501	if (iucv_nonsmp_handler == 0 || cpumask_empty(srcp: &iucv_irq_cpumask))
502	/* Enable iucv interrupts on this cpu. */
503	iucv_allow_cpu(NULL);
504	else
505	/* Disable iucv interrupts on this cpu. */
506	iucv_block_cpu(NULL);
507	}
508
509	/**
510	* iucv_retrieve_cpu
511	* @data: unused
512	*
513	* Retrieve interrupt buffer on this cpu.
514	*/
515	static void iucv_retrieve_cpu(void *data)
516	{
517	int cpu = smp_processor_id();
518	union iucv_param *parm;
519
520	if (!cpumask_test_cpu(cpu, cpumask: &iucv_buffer_cpumask))
521	return;
522
523	/* Block iucv interrupts. */
524	iucv_block_cpu(NULL);
525
526	/* Retrieve interrupt buffer. */
527	parm = iucv_param_irq[cpu];
528	iucv_call_b2f0(command: IUCV_RETRIEVE_BUFFER, parm);
529
530	/* Clear indication that an iucv buffer exists for this cpu. */
531	cpumask_clear_cpu(cpu, dstp: &iucv_buffer_cpumask);
532	}
533
534	/*
535	* iucv_setmask_mp
536	*
537	* Allow iucv interrupts on all cpus.
538	*/
539	static void iucv_setmask_mp(void)
540	{
541	int cpu;
542
543	cpus_read_lock();
544	for_each_online_cpu(cpu)
545	/* Enable all cpus with a declared buffer. */
546	if (cpumask_test_cpu(cpu, cpumask: &iucv_buffer_cpumask) &&
547	!cpumask_test_cpu(cpu, cpumask: &iucv_irq_cpumask))
548	smp_call_function_single(cpuid: cpu, func: iucv_allow_cpu,
549	NULL, wait: 1);
550	cpus_read_unlock();
551	}
552
553	/*
554	* iucv_setmask_up
555	*
556	* Allow iucv interrupts on a single cpu.
557	*/
558	static void iucv_setmask_up(void)
559	{
560	static cpumask_t cpumask;
561	int cpu;
562
563	/* Disable all cpu but the first in cpu_irq_cpumask. */
564	cpumask_copy(dstp: &cpumask, srcp: &iucv_irq_cpumask);
565	cpumask_clear_cpu(cpu: cpumask_first(srcp: &iucv_irq_cpumask), dstp: &cpumask);
566	for_each_cpu(cpu, &cpumask)
567	smp_call_function_single(cpuid: cpu, func: iucv_block_cpu, NULL, wait: 1);
568	}
569
570	/*
571	* iucv_enable
572	*
573	* This function makes iucv ready for use. It allocates the pathid
574	* table, declares an iucv interrupt buffer and enables the iucv
575	* interrupts. Called when the first user has registered an iucv
576	* handler.
577	*/
578	static int iucv_enable(void)
579	{
580	size_t alloc_size;
581	int cpu, rc;
582
583	cpus_read_lock();
584	rc = -ENOMEM;
585	alloc_size = iucv_max_pathid * sizeof(*iucv_path_table);
586	iucv_path_table = kzalloc(alloc_size, GFP_KERNEL);
587	if (!iucv_path_table)
588	goto out;
589	/* Declare per cpu buffers. */
590	rc = -EIO;
591	for_each_online_cpu(cpu)
592	smp_call_function_single(cpuid: cpu, func: iucv_declare_cpu, NULL, wait: 1);
593	if (cpumask_empty(srcp: &iucv_buffer_cpumask))
594	/* No cpu could declare an iucv buffer. */
595	goto out;
596	cpus_read_unlock();
597	return 0;
598	out:
599	kfree(objp: iucv_path_table);
600	iucv_path_table = NULL;
601	cpus_read_unlock();
602	return rc;
603	}
604
605	/*
606	* iucv_disable
607	*
608	* This function shuts down iucv. It disables iucv interrupts, retrieves
609	* the iucv interrupt buffer and frees the pathid table. Called after the
610	* last user unregister its iucv handler.
611	*/
612	static void iucv_disable(void)
613	{
614	cpus_read_lock();
615	on_each_cpu(func: iucv_retrieve_cpu, NULL, wait: 1);
616	kfree(objp: iucv_path_table);
617	iucv_path_table = NULL;
618	cpus_read_unlock();
619	}
620
621	static int iucv_cpu_dead(unsigned int cpu)
622	{
623	kfree(objp: iucv_param_irq[cpu]);
624	iucv_param_irq[cpu] = NULL;
625	kfree(objp: iucv_param[cpu]);
626	iucv_param[cpu] = NULL;
627	kfree(objp: iucv_irq_data[cpu]);
628	iucv_irq_data[cpu] = NULL;
629	return 0;
630	}
631
632	static int iucv_cpu_prepare(unsigned int cpu)
633	{
634	/* Note: GFP_DMA used to get memory below 2G */
635	iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
636	GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
637	if (!iucv_irq_data[cpu])
638	goto out_free;
639
640	/* Allocate parameter blocks. */
641	iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
642	GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
643	if (!iucv_param[cpu])
644	goto out_free;
645
646	iucv_param_irq[cpu] = kmalloc_node(sizeof(union iucv_param),
647	GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
648	if (!iucv_param_irq[cpu])
649	goto out_free;
650
651	return 0;
652
653	out_free:
654	iucv_cpu_dead(cpu);
655	return -ENOMEM;
656	}
657
658	static int iucv_cpu_online(unsigned int cpu)
659	{
660	if (!iucv_path_table)
661	return 0;
662	iucv_declare_cpu(NULL);
663	return 0;
664	}
665
666	static int iucv_cpu_down_prep(unsigned int cpu)
667	{
668	cpumask_var_t cpumask;
669	int ret = 0;
670
671	if (!iucv_path_table)
672	return 0;
673
674	if (!alloc_cpumask_var(mask: &cpumask, GFP_KERNEL))
675	return -ENOMEM;
676
677	cpumask_copy(dstp: cpumask, srcp: &iucv_buffer_cpumask);
678	cpumask_clear_cpu(cpu, dstp: cpumask);
679	if (cpumask_empty(srcp: cpumask)) {
680	/* Can't offline last IUCV enabled cpu. */
681	ret = -EINVAL;
682	goto __free_cpumask;
683	}
684
685	iucv_retrieve_cpu(NULL);
686	if (!cpumask_empty(srcp: &iucv_irq_cpumask))
687	goto __free_cpumask;
688
689	smp_call_function_single(cpuid: cpumask_first(srcp: &iucv_buffer_cpumask),
690	func: iucv_allow_cpu, NULL, wait: 1);
691
692	__free_cpumask:
693	free_cpumask_var(mask: cpumask);
694	return ret;
695	}
696
697	/**
698	* iucv_sever_pathid
699	* @pathid: path identification number.
700	* @userdata: 16-bytes of user data.
701	*
702	* Sever an iucv path to free up the pathid. Used internally.
703	*/
704	static int iucv_sever_pathid(u16 pathid, u8 *userdata)
705	{
706	union iucv_param *parm;
707
708	parm = iucv_param_irq[smp_processor_id()];
709	memset(parm, 0, sizeof(union iucv_param));
710	if (userdata)
711	memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
712	parm->ctrl.ippathid = pathid;
713	return iucv_call_b2f0(command: IUCV_SEVER, parm);
714	}
715
716	/**
717	* __iucv_cleanup_queue
718	* @dummy: unused dummy argument
719	*
720	* Nop function called via smp_call_function to force work items from
721	* pending external iucv interrupts to the work queue.
722	*/
723	static void __iucv_cleanup_queue(void *dummy)
724	{
725	}
726
727	/**
728	* iucv_cleanup_queue
729	*
730	* Function called after a path has been severed to find all remaining
731	* work items for the now stale pathid. The caller needs to hold the
732	* iucv_table_lock.
733	*/
734	static void iucv_cleanup_queue(void)
735	{
736	struct iucv_irq_list *p, *n;
737
738	/*
739	* When a path is severed, the pathid can be reused immediately
740	* on a iucv connect or a connection pending interrupt. Remove
741	* all entries from the task queue that refer to a stale pathid
742	* (iucv_path_table[ix] == NULL). Only then do the iucv connect
743	* or deliver the connection pending interrupt. To get all the
744	* pending interrupts force them to the work queue by calling
745	* an empty function on all cpus.
746	*/
747	smp_call_function(func: __iucv_cleanup_queue, NULL, wait: 1);
748	spin_lock_irq(lock: &iucv_queue_lock);
749	list_for_each_entry_safe(p, n, &iucv_task_queue, list) {
750	/* Remove stale work items from the task queue. */
751	if (iucv_path_table[p->data.ippathid] == NULL) {
752	list_del(entry: &p->list);
753	kfree(objp: p);
754	}
755	}
756	spin_unlock_irq(lock: &iucv_queue_lock);
757	}
758
759	/**
760	* iucv_register:
761	* @handler: address of iucv handler structure
762	* @smp: != 0 indicates that the handler can deal with out of order messages
763	*
764	* Registers a driver with IUCV.
765	*
766	* Returns 0 on success, -ENOMEM if the memory allocation for the pathid
767	* table failed, or -EIO if IUCV_DECLARE_BUFFER failed on all cpus.
768	*/
769	int iucv_register(struct iucv_handler *handler, int smp)
770	{
771	int rc;
772
773	if (!iucv_available)
774	return -ENOSYS;
775	mutex_lock(&iucv_register_mutex);
776	if (!smp)
777	iucv_nonsmp_handler++;
778	if (list_empty(head: &iucv_handler_list)) {
779	rc = iucv_enable();
780	if (rc)
781	goto out_mutex;
782	} else if (!smp && iucv_nonsmp_handler == 1)
783	iucv_setmask_up();
784	INIT_LIST_HEAD(list: &handler->paths);
785
786	spin_lock_bh(lock: &iucv_table_lock);
787	list_add_tail(new: &handler->list, head: &iucv_handler_list);
788	spin_unlock_bh(lock: &iucv_table_lock);
789	rc = 0;
790	out_mutex:
791	mutex_unlock(lock: &iucv_register_mutex);
792	return rc;
793	}
794	EXPORT_SYMBOL(iucv_register);
795
796	/**
797	* iucv_unregister
798	* @handler: address of iucv handler structure
799	* @smp: != 0 indicates that the handler can deal with out of order messages
800	*
801	* Unregister driver from IUCV.
802	*/
803	void iucv_unregister(struct iucv_handler *handler, int smp)
804	{
805	struct iucv_path *p, *n;
806
807	mutex_lock(&iucv_register_mutex);
808	spin_lock_bh(lock: &iucv_table_lock);
809	/* Remove handler from the iucv_handler_list. */
810	list_del_init(entry: &handler->list);
811	/* Sever all pathids still referring to the handler. */
812	list_for_each_entry_safe(p, n, &handler->paths, list) {
813	iucv_sever_pathid(pathid: p->pathid, NULL);
814	iucv_path_table[p->pathid] = NULL;
815	list_del(entry: &p->list);
816	iucv_path_free(path: p);
817	}
818	spin_unlock_bh(lock: &iucv_table_lock);
819	if (!smp)
820	iucv_nonsmp_handler--;
821	if (list_empty(head: &iucv_handler_list))
822	iucv_disable();
823	else if (!smp && iucv_nonsmp_handler == 0)
824	iucv_setmask_mp();
825	mutex_unlock(lock: &iucv_register_mutex);
826	}
827	EXPORT_SYMBOL(iucv_unregister);
828
829	static int iucv_reboot_event(struct notifier_block *this,
830	unsigned long event, void *ptr)
831	{
832	int i;
833
834	if (cpumask_empty(srcp: &iucv_irq_cpumask))
835	return NOTIFY_DONE;
836
837	cpus_read_lock();
838	on_each_cpu_mask(mask: &iucv_irq_cpumask, func: iucv_block_cpu, NULL, wait: 1);
839	preempt_disable();
840	for (i = 0; i < iucv_max_pathid; i++) {
841	if (iucv_path_table[i])
842	iucv_sever_pathid(pathid: i, NULL);
843	}
844	preempt_enable();
845	cpus_read_unlock();
846	iucv_disable();
847	return NOTIFY_DONE;
848	}
849
850	static struct notifier_block iucv_reboot_notifier = {
851	.notifier_call = iucv_reboot_event,
852	};
853
854	/**
855	* iucv_path_accept
856	* @path: address of iucv path structure
857	* @handler: address of iucv handler structure
858	* @userdata: 16 bytes of data reflected to the communication partner
859	* @private: private data passed to interrupt handlers for this path
860	*
861	* This function is issued after the user received a connection pending
862	* external interrupt and now wishes to complete the IUCV communication path.
863	*
864	* Returns the result of the CP IUCV call.
865	*/
866	int iucv_path_accept(struct iucv_path *path, struct iucv_handler *handler,
867	u8 *userdata, void *private)
868	{
869	union iucv_param *parm;
870	int rc;
871
872	local_bh_disable();
873	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
874	rc = -EIO;
875	goto out;
876	}
877	/* Prepare parameter block. */
878	parm = iucv_param[smp_processor_id()];
879	memset(parm, 0, sizeof(union iucv_param));
880	parm->ctrl.ippathid = path->pathid;
881	parm->ctrl.ipmsglim = path->msglim;
882	if (userdata)
883	memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
884	parm->ctrl.ipflags1 = path->flags;
885
886	rc = iucv_call_b2f0(command: IUCV_ACCEPT, parm);
887	if (!rc) {
888	path->private = private;
889	path->msglim = parm->ctrl.ipmsglim;
890	path->flags = parm->ctrl.ipflags1;
891	}
892	out:
893	local_bh_enable();
894	return rc;
895	}
896	EXPORT_SYMBOL(iucv_path_accept);
897
898	/**
899	* iucv_path_connect
900	* @path: address of iucv path structure
901	* @handler: address of iucv handler structure
902	* @userid: 8-byte user identification
903	* @system: 8-byte target system identification
904	* @userdata: 16 bytes of data reflected to the communication partner
905	* @private: private data passed to interrupt handlers for this path
906	*
907	* This function establishes an IUCV path. Although the connect may complete
908	* successfully, you are not able to use the path until you receive an IUCV
909	* Connection Complete external interrupt.
910	*
911	* Returns the result of the CP IUCV call.
912	*/
913	int iucv_path_connect(struct iucv_path *path, struct iucv_handler *handler,
914	u8 *userid, u8 *system, u8 *userdata,
915	void *private)
916	{
917	union iucv_param *parm;
918	int rc;
919
920	spin_lock_bh(lock: &iucv_table_lock);
921	iucv_cleanup_queue();
922	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
923	rc = -EIO;
924	goto out;
925	}
926	parm = iucv_param[smp_processor_id()];
927	memset(parm, 0, sizeof(union iucv_param));
928	parm->ctrl.ipmsglim = path->msglim;
929	parm->ctrl.ipflags1 = path->flags;
930	if (userid) {
931	memcpy(parm->ctrl.ipvmid, userid, sizeof(parm->ctrl.ipvmid));
932	ASCEBC(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
933	EBC_TOUPPER(parm->ctrl.ipvmid, sizeof(parm->ctrl.ipvmid));
934	}
935	if (system) {
936	memcpy(parm->ctrl.iptarget, system,
937	sizeof(parm->ctrl.iptarget));
938	ASCEBC(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
939	EBC_TOUPPER(parm->ctrl.iptarget, sizeof(parm->ctrl.iptarget));
940	}
941	if (userdata)
942	memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
943
944	rc = iucv_call_b2f0(command: IUCV_CONNECT, parm);
945	if (!rc) {
946	if (parm->ctrl.ippathid < iucv_max_pathid) {
947	path->pathid = parm->ctrl.ippathid;
948	path->msglim = parm->ctrl.ipmsglim;
949	path->flags = parm->ctrl.ipflags1;
950	path->handler = handler;
951	path->private = private;
952	list_add_tail(new: &path->list, head: &handler->paths);
953	iucv_path_table[path->pathid] = path;
954	} else {
955	iucv_sever_pathid(pathid: parm->ctrl.ippathid,
956	userdata: iucv_error_pathid);
957	rc = -EIO;
958	}
959	}
960	out:
961	spin_unlock_bh(lock: &iucv_table_lock);
962	return rc;
963	}
964	EXPORT_SYMBOL(iucv_path_connect);
965
966	/**
967	* iucv_path_quiesce:
968	* @path: address of iucv path structure
969	* @userdata: 16 bytes of data reflected to the communication partner
970	*
971	* This function temporarily suspends incoming messages on an IUCV path.
972	* You can later reactivate the path by invoking the iucv_resume function.
973	*
974	* Returns the result from the CP IUCV call.
975	*/
976	int iucv_path_quiesce(struct iucv_path *path, u8 *userdata)
977	{
978	union iucv_param *parm;
979	int rc;
980
981	local_bh_disable();
982	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
983	rc = -EIO;
984	goto out;
985	}
986	parm = iucv_param[smp_processor_id()];
987	memset(parm, 0, sizeof(union iucv_param));
988	if (userdata)
989	memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
990	parm->ctrl.ippathid = path->pathid;
991	rc = iucv_call_b2f0(command: IUCV_QUIESCE, parm);
992	out:
993	local_bh_enable();
994	return rc;
995	}
996	EXPORT_SYMBOL(iucv_path_quiesce);
997
998	/**
999	* iucv_path_resume:
1000	* @path: address of iucv path structure
1001	* @userdata: 16 bytes of data reflected to the communication partner
1002	*
1003	* This function resumes incoming messages on an IUCV path that has
1004	* been stopped with iucv_path_quiesce.
1005	*
1006	* Returns the result from the CP IUCV call.
1007	*/
1008	int iucv_path_resume(struct iucv_path *path, u8 *userdata)
1009	{
1010	union iucv_param *parm;
1011	int rc;
1012
1013	local_bh_disable();
1014	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
1015	rc = -EIO;
1016	goto out;
1017	}
1018	parm = iucv_param[smp_processor_id()];
1019	memset(parm, 0, sizeof(union iucv_param));
1020	if (userdata)
1021	memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
1022	parm->ctrl.ippathid = path->pathid;
1023	rc = iucv_call_b2f0(command: IUCV_RESUME, parm);
1024	out:
1025	local_bh_enable();
1026	return rc;
1027	}
1028
1029	/**
1030	* iucv_path_sever
1031	* @path: address of iucv path structure
1032	* @userdata: 16 bytes of data reflected to the communication partner
1033	*
1034	* This function terminates an IUCV path.
1035	*
1036	* Returns the result from the CP IUCV call.
1037	*/
1038	int iucv_path_sever(struct iucv_path *path, u8 *userdata)
1039	{
1040	int rc;
1041
1042	preempt_disable();
1043	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
1044	rc = -EIO;
1045	goto out;
1046	}
1047	if (iucv_active_cpu != smp_processor_id())
1048	spin_lock_bh(lock: &iucv_table_lock);
1049	rc = iucv_sever_pathid(pathid: path->pathid, userdata);
1050	iucv_path_table[path->pathid] = NULL;
1051	list_del_init(entry: &path->list);
1052	if (iucv_active_cpu != smp_processor_id())
1053	spin_unlock_bh(lock: &iucv_table_lock);
1054	out:
1055	preempt_enable();
1056	return rc;
1057	}
1058	EXPORT_SYMBOL(iucv_path_sever);
1059
1060	/**
1061	* iucv_message_purge
1062	* @path: address of iucv path structure
1063	* @msg: address of iucv msg structure
1064	* @srccls: source class of message
1065	*
1066	* Cancels a message you have sent.
1067	*
1068	* Returns the result from the CP IUCV call.
1069	*/
1070	int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg,
1071	u32 srccls)
1072	{
1073	union iucv_param *parm;
1074	int rc;
1075
1076	local_bh_disable();
1077	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
1078	rc = -EIO;
1079	goto out;
1080	}
1081	parm = iucv_param[smp_processor_id()];
1082	memset(parm, 0, sizeof(union iucv_param));
1083	parm->purge.ippathid = path->pathid;
1084	parm->purge.ipmsgid = msg->id;
1085	parm->purge.ipsrccls = srccls;
1086	parm->purge.ipflags1 = IUCV_IPSRCCLS | IUCV_IPFGMID | IUCV_IPFGPID;
1087	rc = iucv_call_b2f0(command: IUCV_PURGE, parm);
1088	if (!rc) {
1089	msg->audit = (*(u32 *) &parm->purge.ipaudit) >> 8;
1090	msg->tag = parm->purge.ipmsgtag;
1091	}
1092	out:
1093	local_bh_enable();
1094	return rc;
1095	}
1096	EXPORT_SYMBOL(iucv_message_purge);
1097
1098	/**
1099	* iucv_message_receive_iprmdata
1100	* @path: address of iucv path structure
1101	* @msg: address of iucv msg structure
1102	* @flags: how the message is received (IUCV_IPBUFLST)
1103	* @buffer: address of data buffer or address of struct iucv_array
1104	* @size: length of data buffer
1105	* @residual:
1106	*
1107	* Internal function used by iucv_message_receive and __iucv_message_receive
1108	* to receive RMDATA data stored in struct iucv_message.
1109	*/
1110	static int iucv_message_receive_iprmdata(struct iucv_path *path,
1111	struct iucv_message *msg,
1112	u8 flags, void *buffer,
1113	size_t size, size_t *residual)
1114	{
1115	struct iucv_array *array;
1116	u8 *rmmsg;
1117	size_t copy;
1118
1119	/*
1120	* Message is 8 bytes long and has been stored to the
1121	* message descriptor itself.
1122	*/
1123	if (residual)
1124	*residual = abs(size - 8);
1125	rmmsg = msg->rmmsg;
1126	if (flags & IUCV_IPBUFLST) {
1127	/* Copy to struct iucv_array. */
1128	size = (size < 8) ? size : 8;
1129	for (array = buffer; size > 0; array++) {
1130	copy = min_t(size_t, size, array->length);
1131	memcpy(dma32_to_virt(array->address), rmmsg, copy);
1132	rmmsg += copy;
1133	size -= copy;
1134	}
1135	} else {
1136	/* Copy to direct buffer. */
1137	memcpy(buffer, rmmsg, min_t(size_t, size, 8));
1138	}
1139	return 0;
1140	}
1141
1142	/**
1143	* __iucv_message_receive
1144	* @path: address of iucv path structure
1145	* @msg: address of iucv msg structure
1146	* @flags: how the message is received (IUCV_IPBUFLST)
1147	* @buffer: address of data buffer or address of struct iucv_array
1148	* @size: length of data buffer
1149	* @residual:
1150	*
1151	* This function receives messages that are being sent to you over
1152	* established paths. This function will deal with RMDATA messages
1153	* embedded in struct iucv_message as well.
1154	*
1155	* Locking: no locking
1156	*
1157	* Returns the result from the CP IUCV call.
1158	*/
1159	int __iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
1160	u8 flags, void *buffer, size_t size, size_t *residual)
1161	{
1162	union iucv_param *parm;
1163	int rc;
1164
1165	if (msg->flags & IUCV_IPRMDATA)
1166	return iucv_message_receive_iprmdata(path, msg, flags,
1167	buffer, size, residual);
1168	if (cpumask_empty(srcp: &iucv_buffer_cpumask))
1169	return -EIO;
1170
1171	parm = iucv_param[smp_processor_id()];
1172	memset(parm, 0, sizeof(union iucv_param));
1173	parm->db.ipbfadr1 = virt_to_dma32(buffer);
1174	parm->db.ipbfln1f = (u32) size;
1175	parm->db.ipmsgid = msg->id;
1176	parm->db.ippathid = path->pathid;
1177	parm->db.iptrgcls = msg->class;
1178	parm->db.ipflags1 = (flags | IUCV_IPFGPID |
1179	IUCV_IPFGMID | IUCV_IPTRGCLS);
1180	rc = iucv_call_b2f0(command: IUCV_RECEIVE, parm);
1181	if (!rc || rc == 5) {
1182	msg->flags = parm->db.ipflags1;
1183	if (residual)
1184	*residual = parm->db.ipbfln1f;
1185	}
1186	return rc;
1187	}
1188	EXPORT_SYMBOL(__iucv_message_receive);
1189
1190	/**
1191	* iucv_message_receive
1192	* @path: address of iucv path structure
1193	* @msg: address of iucv msg structure
1194	* @flags: how the message is received (IUCV_IPBUFLST)
1195	* @buffer: address of data buffer or address of struct iucv_array
1196	* @size: length of data buffer
1197	* @residual:
1198	*
1199	* This function receives messages that are being sent to you over
1200	* established paths. This function will deal with RMDATA messages
1201	* embedded in struct iucv_message as well.
1202	*
1203	* Locking: local_bh_enable/local_bh_disable
1204	*
1205	* Returns the result from the CP IUCV call.
1206	*/
1207	int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
1208	u8 flags, void *buffer, size_t size, size_t *residual)
1209	{
1210	int rc;
1211
1212	if (msg->flags & IUCV_IPRMDATA)
1213	return iucv_message_receive_iprmdata(path, msg, flags,
1214	buffer, size, residual);
1215	local_bh_disable();
1216	rc = __iucv_message_receive(path, msg, flags, buffer, size, residual);
1217	local_bh_enable();
1218	return rc;
1219	}
1220	EXPORT_SYMBOL(iucv_message_receive);
1221
1222	/**
1223	* iucv_message_reject
1224	* @path: address of iucv path structure
1225	* @msg: address of iucv msg structure
1226	*
1227	* The reject function refuses a specified message. Between the time you
1228	* are notified of a message and the time that you complete the message,
1229	* the message may be rejected.
1230	*
1231	* Returns the result from the CP IUCV call.
1232	*/
1233	int iucv_message_reject(struct iucv_path *path, struct iucv_message *msg)
1234	{
1235	union iucv_param *parm;
1236	int rc;
1237
1238	local_bh_disable();
1239	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
1240	rc = -EIO;
1241	goto out;
1242	}
1243	parm = iucv_param[smp_processor_id()];
1244	memset(parm, 0, sizeof(union iucv_param));
1245	parm->db.ippathid = path->pathid;
1246	parm->db.ipmsgid = msg->id;
1247	parm->db.iptrgcls = msg->class;
1248	parm->db.ipflags1 = (IUCV_IPTRGCLS | IUCV_IPFGMID | IUCV_IPFGPID);
1249	rc = iucv_call_b2f0(command: IUCV_REJECT, parm);
1250	out:
1251	local_bh_enable();
1252	return rc;
1253	}
1254	EXPORT_SYMBOL(iucv_message_reject);
1255
1256	/**
1257	* iucv_message_reply
1258	* @path: address of iucv path structure
1259	* @msg: address of iucv msg structure
1260	* @flags: how the reply is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1261	* @reply: address of reply data buffer or address of struct iucv_array
1262	* @size: length of reply data buffer
1263	*
1264	* This function responds to the two-way messages that you receive. You
1265	* must identify completely the message to which you wish to reply. ie,
1266	* pathid, msgid, and trgcls. Prmmsg signifies the data is moved into
1267	* the parameter list.
1268	*
1269	* Returns the result from the CP IUCV call.
1270	*/
1271	int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg,
1272	u8 flags, void *reply, size_t size)
1273	{
1274	union iucv_param *parm;
1275	int rc;
1276
1277	local_bh_disable();
1278	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
1279	rc = -EIO;
1280	goto out;
1281	}
1282	parm = iucv_param[smp_processor_id()];
1283	memset(parm, 0, sizeof(union iucv_param));
1284	if (flags & IUCV_IPRMDATA) {
1285	parm->dpl.ippathid = path->pathid;
1286	parm->dpl.ipflags1 = flags;
1287	parm->dpl.ipmsgid = msg->id;
1288	parm->dpl.iptrgcls = msg->class;
1289	memcpy(parm->dpl.iprmmsg, reply, min_t(size_t, size, 8));
1290	} else {
1291	parm->db.ipbfadr1 = virt_to_dma32(reply);
1292	parm->db.ipbfln1f = (u32) size;
1293	parm->db.ippathid = path->pathid;
1294	parm->db.ipflags1 = flags;
1295	parm->db.ipmsgid = msg->id;
1296	parm->db.iptrgcls = msg->class;
1297	}
1298	rc = iucv_call_b2f0(command: IUCV_REPLY, parm);
1299	out:
1300	local_bh_enable();
1301	return rc;
1302	}
1303	EXPORT_SYMBOL(iucv_message_reply);
1304
1305	/**
1306	* __iucv_message_send
1307	* @path: address of iucv path structure
1308	* @msg: address of iucv msg structure
1309	* @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1310	* @srccls: source class of message
1311	* @buffer: address of send buffer or address of struct iucv_array
1312	* @size: length of send buffer
1313	*
1314	* This function transmits data to another application. Data to be
1315	* transmitted is in a buffer and this is a one-way message and the
1316	* receiver will not reply to the message.
1317	*
1318	* Locking: no locking
1319	*
1320	* Returns the result from the CP IUCV call.
1321	*/
1322	int __iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
1323	u8 flags, u32 srccls, void *buffer, size_t size)
1324	{
1325	union iucv_param *parm;
1326	int rc;
1327
1328	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
1329	rc = -EIO;
1330	goto out;
1331	}
1332	parm = iucv_param[smp_processor_id()];
1333	memset(parm, 0, sizeof(union iucv_param));
1334	if (flags & IUCV_IPRMDATA) {
1335	/* Message of 8 bytes can be placed into the parameter list. */
1336	parm->dpl.ippathid = path->pathid;
1337	parm->dpl.ipflags1 = flags | IUCV_IPNORPY;
1338	parm->dpl.iptrgcls = msg->class;
1339	parm->dpl.ipsrccls = srccls;
1340	parm->dpl.ipmsgtag = msg->tag;
1341	memcpy(parm->dpl.iprmmsg, buffer, 8);
1342	} else {
1343	parm->db.ipbfadr1 = virt_to_dma32(buffer);
1344	parm->db.ipbfln1f = (u32) size;
1345	parm->db.ippathid = path->pathid;
1346	parm->db.ipflags1 = flags | IUCV_IPNORPY;
1347	parm->db.iptrgcls = msg->class;
1348	parm->db.ipsrccls = srccls;
1349	parm->db.ipmsgtag = msg->tag;
1350	}
1351	rc = iucv_call_b2f0(command: IUCV_SEND, parm);
1352	if (!rc)
1353	msg->id = parm->db.ipmsgid;
1354	out:
1355	return rc;
1356	}
1357	EXPORT_SYMBOL(__iucv_message_send);
1358
1359	/**
1360	* iucv_message_send
1361	* @path: address of iucv path structure
1362	* @msg: address of iucv msg structure
1363	* @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
1364	* @srccls: source class of message
1365	* @buffer: address of send buffer or address of struct iucv_array
1366	* @size: length of send buffer
1367	*
1368	* This function transmits data to another application. Data to be
1369	* transmitted is in a buffer and this is a one-way message and the
1370	* receiver will not reply to the message.
1371	*
1372	* Locking: local_bh_enable/local_bh_disable
1373	*
1374	* Returns the result from the CP IUCV call.
1375	*/
1376	int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
1377	u8 flags, u32 srccls, void *buffer, size_t size)
1378	{
1379	int rc;
1380
1381	local_bh_disable();
1382	rc = __iucv_message_send(path, msg, flags, srccls, buffer, size);
1383	local_bh_enable();
1384	return rc;
1385	}
1386	EXPORT_SYMBOL(iucv_message_send);
1387
1388	/**
1389	* iucv_message_send2way
1390	* @path: address of iucv path structure
1391	* @msg: address of iucv msg structure
1392	* @flags: how the message is sent and the reply is received
1393	* (IUCV_IPRMDATA, IUCV_IPBUFLST, IUCV_IPPRTY, IUCV_ANSLST)
1394	* @srccls: source class of message
1395	* @buffer: address of send buffer or address of struct iucv_array
1396	* @size: length of send buffer
1397	* @answer: address of answer buffer or address of struct iucv_array
1398	* @asize: size of reply buffer
1399	* @residual: ignored
1400	*
1401	* This function transmits data to another application. Data to be
1402	* transmitted is in a buffer. The receiver of the send is expected to
1403	* reply to the message and a buffer is provided into which IUCV moves
1404	* the reply to this message.
1405	*
1406	* Returns the result from the CP IUCV call.
1407	*/
1408	int iucv_message_send2way(struct iucv_path *path, struct iucv_message *msg,
1409	u8 flags, u32 srccls, void *buffer, size_t size,
1410	void *answer, size_t asize, size_t *residual)
1411	{
1412	union iucv_param *parm;
1413	int rc;
1414
1415	local_bh_disable();
1416	if (cpumask_empty(srcp: &iucv_buffer_cpumask)) {
1417	rc = -EIO;
1418	goto out;
1419	}
1420	parm = iucv_param[smp_processor_id()];
1421	memset(parm, 0, sizeof(union iucv_param));
1422	if (flags & IUCV_IPRMDATA) {
1423	parm->dpl.ippathid = path->pathid;
1424	parm->dpl.ipflags1 = path->flags; /* priority message */
1425	parm->dpl.iptrgcls = msg->class;
1426	parm->dpl.ipsrccls = srccls;
1427	parm->dpl.ipmsgtag = msg->tag;
1428	parm->dpl.ipbfadr2 = virt_to_dma32(answer);
1429	parm->dpl.ipbfln2f = (u32) asize;
1430	memcpy(parm->dpl.iprmmsg, buffer, 8);
1431	} else {
1432	parm->db.ippathid = path->pathid;
1433	parm->db.ipflags1 = path->flags; /* priority message */
1434	parm->db.iptrgcls = msg->class;
1435	parm->db.ipsrccls = srccls;
1436	parm->db.ipmsgtag = msg->tag;
1437	parm->db.ipbfadr1 = virt_to_dma32(buffer);
1438	parm->db.ipbfln1f = (u32) size;
1439	parm->db.ipbfadr2 = virt_to_dma32(answer);
1440	parm->db.ipbfln2f = (u32) asize;
1441	}
1442	rc = iucv_call_b2f0(command: IUCV_SEND, parm);
1443	if (!rc)
1444	msg->id = parm->db.ipmsgid;
1445	out:
1446	local_bh_enable();
1447	return rc;
1448	}
1449	EXPORT_SYMBOL(iucv_message_send2way);
1450
1451	struct iucv_path_pending {
1452	u16 ippathid;
1453	u8 ipflags1;
1454	u8 iptype;
1455	u16 ipmsglim;
1456	u16 res1;
1457	u8 ipvmid[8];
1458	u8 ipuser[16];
1459	u32 res3;
1460	u8 ippollfg;
1461	u8 res4[3];
1462	} __packed;
1463
1464	/**
1465	* iucv_path_pending
1466	* @data: Pointer to external interrupt buffer
1467	*
1468	* Process connection pending work item. Called from tasklet while holding
1469	* iucv_table_lock.
1470	*/
1471	static void iucv_path_pending(struct iucv_irq_data *data)
1472	{
1473	struct iucv_path_pending *ipp = (void *) data;
1474	struct iucv_handler *handler;
1475	struct iucv_path *path;
1476	char *error;
1477
1478	BUG_ON(iucv_path_table[ipp->ippathid]);
1479	/* New pathid, handler found. Create a new path struct. */
1480	error = iucv_error_no_memory;
1481	path = iucv_path_alloc(msglim: ipp->ipmsglim, flags: ipp->ipflags1, GFP_ATOMIC);
1482	if (!path)
1483	goto out_sever;
1484	path->pathid = ipp->ippathid;
1485	iucv_path_table[path->pathid] = path;
1486	EBCASC(ipp->ipvmid, 8);
1487
1488	/* Call registered handler until one is found that wants the path. */
1489	list_for_each_entry(handler, &iucv_handler_list, list) {
1490	if (!handler->path_pending)
1491	continue;
1492	/*
1493	* Add path to handler to allow a call to iucv_path_sever
1494	* inside the path_pending function. If the handler returns
1495	* an error remove the path from the handler again.
1496	*/
1497	list_add(new: &path->list, head: &handler->paths);
1498	path->handler = handler;
1499	if (!handler->path_pending(path, ipp->ipvmid, ipp->ipuser))
1500	return;
1501	list_del(entry: &path->list);
1502	path->handler = NULL;
1503	}
1504	/* No handler wanted the path. */
1505	iucv_path_table[path->pathid] = NULL;
1506	iucv_path_free(path);
1507	error = iucv_error_no_listener;
1508	out_sever:
1509	iucv_sever_pathid(pathid: ipp->ippathid, userdata: error);
1510	}
1511
1512	struct iucv_path_complete {
1513	u16 ippathid;
1514	u8 ipflags1;
1515	u8 iptype;
1516	u16 ipmsglim;
1517	u16 res1;
1518	u8 res2[8];
1519	u8 ipuser[16];
1520	u32 res3;
1521	u8 ippollfg;
1522	u8 res4[3];
1523	} __packed;
1524
1525	/**
1526	* iucv_path_complete
1527	* @data: Pointer to external interrupt buffer
1528	*
1529	* Process connection complete work item. Called from tasklet while holding
1530	* iucv_table_lock.
1531	*/
1532	static void iucv_path_complete(struct iucv_irq_data *data)
1533	{
1534	struct iucv_path_complete *ipc = (void *) data;
1535	struct iucv_path *path = iucv_path_table[ipc->ippathid];
1536
1537	if (path)
1538	path->flags = ipc->ipflags1;
1539	if (path && path->handler && path->handler->path_complete)
1540	path->handler->path_complete(path, ipc->ipuser);
1541	}
1542
1543	struct iucv_path_severed {
1544	u16 ippathid;
1545	u8 res1;
1546	u8 iptype;
1547	u32 res2;
1548	u8 res3[8];
1549	u8 ipuser[16];
1550	u32 res4;
1551	u8 ippollfg;
1552	u8 res5[3];
1553	} __packed;
1554
1555	/**
1556	* iucv_path_severed
1557	* @data: Pointer to external interrupt buffer
1558	*
1559	* Process connection severed work item. Called from tasklet while holding
1560	* iucv_table_lock.
1561	*/
1562	static void iucv_path_severed(struct iucv_irq_data *data)
1563	{
1564	struct iucv_path_severed *ips = (void *) data;
1565	struct iucv_path *path = iucv_path_table[ips->ippathid];
1566
1567	if (!path || !path->handler) /* Already severed */
1568	return;
1569	if (path->handler->path_severed)
1570	path->handler->path_severed(path, ips->ipuser);
1571	else {
1572	iucv_sever_pathid(pathid: path->pathid, NULL);
1573	iucv_path_table[path->pathid] = NULL;
1574	list_del(entry: &path->list);
1575	iucv_path_free(path);
1576	}
1577	}
1578
1579	struct iucv_path_quiesced {
1580	u16 ippathid;
1581	u8 res1;
1582	u8 iptype;
1583	u32 res2;
1584	u8 res3[8];
1585	u8 ipuser[16];
1586	u32 res4;
1587	u8 ippollfg;
1588	u8 res5[3];
1589	} __packed;
1590
1591	/**
1592	* iucv_path_quiesced
1593	* @data: Pointer to external interrupt buffer
1594	*
1595	* Process connection quiesced work item. Called from tasklet while holding
1596	* iucv_table_lock.
1597	*/
1598	static void iucv_path_quiesced(struct iucv_irq_data *data)
1599	{
1600	struct iucv_path_quiesced *ipq = (void *) data;
1601	struct iucv_path *path = iucv_path_table[ipq->ippathid];
1602
1603	if (path && path->handler && path->handler->path_quiesced)
1604	path->handler->path_quiesced(path, ipq->ipuser);
1605	}
1606
1607	struct iucv_path_resumed {
1608	u16 ippathid;
1609	u8 res1;
1610	u8 iptype;
1611	u32 res2;
1612	u8 res3[8];
1613	u8 ipuser[16];
1614	u32 res4;
1615	u8 ippollfg;
1616	u8 res5[3];
1617	} __packed;
1618
1619	/**
1620	* iucv_path_resumed
1621	* @data: Pointer to external interrupt buffer
1622	*
1623	* Process connection resumed work item. Called from tasklet while holding
1624	* iucv_table_lock.
1625	*/
1626	static void iucv_path_resumed(struct iucv_irq_data *data)
1627	{
1628	struct iucv_path_resumed *ipr = (void *) data;
1629	struct iucv_path *path = iucv_path_table[ipr->ippathid];
1630
1631	if (path && path->handler && path->handler->path_resumed)
1632	path->handler->path_resumed(path, ipr->ipuser);
1633	}
1634
1635	struct iucv_message_complete {
1636	u16 ippathid;
1637	u8 ipflags1;
1638	u8 iptype;
1639	u32 ipmsgid;
1640	u32 ipaudit;
1641	u8 iprmmsg[8];
1642	u32 ipsrccls;
1643	u32 ipmsgtag;
1644	u32 res;
1645	u32 ipbfln2f;
1646	u8 ippollfg;
1647	u8 res2[3];
1648	} __packed;
1649
1650	/**
1651	* iucv_message_complete
1652	* @data: Pointer to external interrupt buffer
1653	*
1654	* Process message complete work item. Called from tasklet while holding
1655	* iucv_table_lock.
1656	*/
1657	static void iucv_message_complete(struct iucv_irq_data *data)
1658	{
1659	struct iucv_message_complete *imc = (void *) data;
1660	struct iucv_path *path = iucv_path_table[imc->ippathid];
1661	struct iucv_message msg;
1662
1663	if (path && path->handler && path->handler->message_complete) {
1664	msg.flags = imc->ipflags1;
1665	msg.id = imc->ipmsgid;
1666	msg.audit = imc->ipaudit;
1667	memcpy(msg.rmmsg, imc->iprmmsg, 8);
1668	msg.class = imc->ipsrccls;
1669	msg.tag = imc->ipmsgtag;
1670	msg.length = imc->ipbfln2f;
1671	path->handler->message_complete(path, &msg);
1672	}
1673	}
1674
1675	struct iucv_message_pending {
1676	u16 ippathid;
1677	u8 ipflags1;
1678	u8 iptype;
1679	u32 ipmsgid;
1680	u32 iptrgcls;
1681	struct {
1682	union {
1683	u32 iprmmsg1_u32;
1684	u8 iprmmsg1[4];
1685	} ln1msg1;
1686	union {
1687	u32 ipbfln1f;
1688	u8 iprmmsg2[4];
1689	} ln1msg2;
1690	} rmmsg;
1691	u32 res1[3];
1692	u32 ipbfln2f;
1693	u8 ippollfg;
1694	u8 res2[3];
1695	} __packed;
1696
1697	/**
1698	* iucv_message_pending
1699	* @data: Pointer to external interrupt buffer
1700	*
1701	* Process message pending work item. Called from tasklet while holding
1702	* iucv_table_lock.
1703	*/
1704	static void iucv_message_pending(struct iucv_irq_data *data)
1705	{
1706	struct iucv_message_pending *imp = (void *) data;
1707	struct iucv_path *path = iucv_path_table[imp->ippathid];
1708	struct iucv_message msg;
1709
1710	if (path && path->handler && path->handler->message_pending) {
1711	msg.flags = imp->ipflags1;
1712	msg.id = imp->ipmsgid;
1713	msg.class = imp->iptrgcls;
1714	if (imp->ipflags1 & IUCV_IPRMDATA) {
1715	memcpy(msg.rmmsg, &imp->rmmsg, 8);
1716	msg.length = 8;
1717	} else
1718	msg.length = imp->rmmsg.ln1msg2.ipbfln1f;
1719	msg.reply_size = imp->ipbfln2f;
1720	path->handler->message_pending(path, &msg);
1721	}
1722	}
1723
1724	/*
1725	* iucv_tasklet_fn:
1726	*
1727	* This tasklet loops over the queue of irq buffers created by
1728	* iucv_external_interrupt, calls the appropriate action handler
1729	* and then frees the buffer.
1730	*/
1731	static void iucv_tasklet_fn(unsigned long ignored)
1732	{
1733	typedef void iucv_irq_fn(struct iucv_irq_data *);
1734	static iucv_irq_fn *irq_fn[] = {
1735	[0x02] = iucv_path_complete,
1736	[0x03] = iucv_path_severed,
1737	[0x04] = iucv_path_quiesced,
1738	[0x05] = iucv_path_resumed,
1739	[0x06] = iucv_message_complete,
1740	[0x07] = iucv_message_complete,
1741	[0x08] = iucv_message_pending,
1742	[0x09] = iucv_message_pending,
1743	};
1744	LIST_HEAD(task_queue);
1745	struct iucv_irq_list *p, *n;
1746
1747	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */
1748	if (!spin_trylock(lock: &iucv_table_lock)) {
1749	tasklet_schedule(t: &iucv_tasklet);
1750	return;
1751	}
1752	iucv_active_cpu = smp_processor_id();
1753
1754	spin_lock_irq(lock: &iucv_queue_lock);
1755	list_splice_init(list: &iucv_task_queue, head: &task_queue);
1756	spin_unlock_irq(lock: &iucv_queue_lock);
1757
1758	list_for_each_entry_safe(p, n, &task_queue, list) {
1759	list_del_init(entry: &p->list);
1760	irq_fn[p->data.iptype](&p->data);
1761	kfree(objp: p);
1762	}
1763
1764	iucv_active_cpu = -1;
1765	spin_unlock(lock: &iucv_table_lock);
1766	}
1767
1768	/*
1769	* iucv_work_fn:
1770	*
1771	* This work function loops over the queue of path pending irq blocks
1772	* created by iucv_external_interrupt, calls the appropriate action
1773	* handler and then frees the buffer.
1774	*/
1775	static void iucv_work_fn(struct work_struct *work)
1776	{
1777	LIST_HEAD(work_queue);
1778	struct iucv_irq_list *p, *n;
1779
1780	/* Serialize tasklet, iucv_path_sever and iucv_path_connect. */
1781	spin_lock_bh(lock: &iucv_table_lock);
1782	iucv_active_cpu = smp_processor_id();
1783
1784	spin_lock_irq(lock: &iucv_queue_lock);
1785	list_splice_init(list: &iucv_work_queue, head: &work_queue);
1786	spin_unlock_irq(lock: &iucv_queue_lock);
1787
1788	iucv_cleanup_queue();
1789	list_for_each_entry_safe(p, n, &work_queue, list) {
1790	list_del_init(entry: &p->list);
1791	iucv_path_pending(data: &p->data);
1792	kfree(objp: p);
1793	}
1794
1795	iucv_active_cpu = -1;
1796	spin_unlock_bh(lock: &iucv_table_lock);
1797	}
1798
1799	/*
1800	* iucv_external_interrupt
1801	*
1802	* Handles external interrupts coming in from CP.
1803	* Places the interrupt buffer on a queue and schedules iucv_tasklet_fn().
1804	*/
1805	static void iucv_external_interrupt(struct ext_code ext_code,
1806	unsigned int param32, unsigned long param64)
1807	{
1808	struct iucv_irq_data *p;
1809	struct iucv_irq_list *work;
1810
1811	inc_irq_stat(IRQEXT_IUC);
1812	p = iucv_irq_data[smp_processor_id()];
1813	if (p->ippathid >= iucv_max_pathid) {
1814	WARN_ON(p->ippathid >= iucv_max_pathid);
1815	iucv_sever_pathid(pathid: p->ippathid, userdata: iucv_error_no_listener);
1816	return;
1817	}
1818	BUG_ON(p->iptype < 0x01 || p->iptype > 0x09);
1819	work = kmalloc(sizeof(struct iucv_irq_list), GFP_ATOMIC);
1820	if (!work) {
1821	pr_warn("iucv_external_interrupt: out of memory\n");
1822	return;
1823	}
1824	memcpy(&work->data, p, sizeof(work->data));
1825	spin_lock(lock: &iucv_queue_lock);
1826	if (p->iptype == 0x01) {
1827	/* Path pending interrupt. */
1828	list_add_tail(new: &work->list, head: &iucv_work_queue);
1829	schedule_work(work: &iucv_work);
1830	} else {
1831	/* The other interrupts. */
1832	list_add_tail(new: &work->list, head: &iucv_task_queue);
1833	tasklet_schedule(t: &iucv_tasklet);
1834	}
1835	spin_unlock(lock: &iucv_queue_lock);
1836	}
1837
1838	struct iucv_interface iucv_if = {
1839	.message_receive = iucv_message_receive,
1840	.__message_receive = __iucv_message_receive,
1841	.message_reply = iucv_message_reply,
1842	.message_reject = iucv_message_reject,
1843	.message_send = iucv_message_send,
1844	.__message_send = __iucv_message_send,
1845	.message_send2way = iucv_message_send2way,
1846	.message_purge = iucv_message_purge,
1847	.path_accept = iucv_path_accept,
1848	.path_connect = iucv_path_connect,
1849	.path_quiesce = iucv_path_quiesce,
1850	.path_resume = iucv_path_resume,
1851	.path_sever = iucv_path_sever,
1852	.iucv_register = iucv_register,
1853	.iucv_unregister = iucv_unregister,
1854	.bus = NULL,
1855	.root = NULL,
1856	};
1857	EXPORT_SYMBOL(iucv_if);
1858
1859	static enum cpuhp_state iucv_online;
1860	/**
1861	* iucv_init
1862	*
1863	* Allocates and initializes various data structures.
1864	*/
1865	static int __init iucv_init(void)
1866	{
1867	int rc;
1868
1869	if (!machine_is_vm()) {
1870	rc = -EPROTONOSUPPORT;
1871	goto out;
1872	}
1873	system_ctl_set_bit(0, CR0_IUCV_BIT);
1874	rc = iucv_query_maxconn();
1875	if (rc)
1876	goto out_ctl;
1877	rc = register_external_irq(EXT_IRQ_IUCV, iucv_external_interrupt);
1878	if (rc)
1879	goto out_ctl;
1880	iucv_root = root_device_register("iucv");
1881	if (IS_ERR(ptr: iucv_root)) {
1882	rc = PTR_ERR(ptr: iucv_root);
1883	goto out_int;
1884	}
1885
1886	rc = cpuhp_setup_state(state: CPUHP_NET_IUCV_PREPARE, name: "net/iucv:prepare",
1887	startup: iucv_cpu_prepare, teardown: iucv_cpu_dead);
1888	if (rc)
1889	goto out_dev;
1890	rc = cpuhp_setup_state(state: CPUHP_AP_ONLINE_DYN, name: "net/iucv:online",
1891	startup: iucv_cpu_online, teardown: iucv_cpu_down_prep);
1892	if (rc < 0)
1893	goto out_prep;
1894	iucv_online = rc;
1895
1896	rc = register_reboot_notifier(&iucv_reboot_notifier);
1897	if (rc)
1898	goto out_remove_hp;
1899	ASCEBC(iucv_error_no_listener, 16);
1900	ASCEBC(iucv_error_no_memory, 16);
1901	ASCEBC(iucv_error_pathid, 16);
1902	iucv_available = 1;
1903	rc = bus_register(bus: &iucv_bus);
1904	if (rc)
1905	goto out_reboot;
1906	iucv_if.root = iucv_root;
1907	iucv_if.bus = &iucv_bus;
1908	return 0;
1909
1910	out_reboot:
1911	unregister_reboot_notifier(&iucv_reboot_notifier);
1912	out_remove_hp:
1913	cpuhp_remove_state(state: iucv_online);
1914	out_prep:
1915	cpuhp_remove_state(state: CPUHP_NET_IUCV_PREPARE);
1916	out_dev:
1917	root_device_unregister(root: iucv_root);
1918	out_int:
1919	unregister_external_irq(EXT_IRQ_IUCV, iucv_external_interrupt);
1920	out_ctl:
1921	system_ctl_clear_bit(0, 1);
1922	out:
1923	return rc;
1924	}
1925
1926	/**
1927	* iucv_exit
1928	*
1929	* Frees everything allocated from iucv_init.
1930	*/
1931	static void __exit iucv_exit(void)
1932	{
1933	struct iucv_irq_list *p, *n;
1934
1935	spin_lock_irq(lock: &iucv_queue_lock);
1936	list_for_each_entry_safe(p, n, &iucv_task_queue, list)
1937	kfree(objp: p);
1938	list_for_each_entry_safe(p, n, &iucv_work_queue, list)
1939	kfree(objp: p);
1940	spin_unlock_irq(lock: &iucv_queue_lock);
1941	unregister_reboot_notifier(&iucv_reboot_notifier);
1942
1943	cpuhp_remove_state_nocalls(state: iucv_online);
1944	cpuhp_remove_state(state: CPUHP_NET_IUCV_PREPARE);
1945	root_device_unregister(root: iucv_root);
1946	bus_unregister(bus: &iucv_bus);
1947	unregister_external_irq(EXT_IRQ_IUCV, iucv_external_interrupt);
1948	}
1949
1950	subsys_initcall(iucv_init);
1951	module_exit(iucv_exit);
1952
1953	MODULE_AUTHOR("(C) 2001 IBM Corp. by Fritz Elfert <felfert@millenux.com>");
1954	MODULE_DESCRIPTION("Linux for S/390 IUCV lowlevel driver");
1955	MODULE_LICENSE("GPL");
1956