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