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