iucv.c

linux 内核源代码

/*
 * IUCV base infrastructure.
 *
 * Copyright 2001, 2006 IBM Deutschland Entwicklung GmbH, IBM Corporation
 * Author(s):
 *    Original source:
 *	Alan Altmark ([e-mail])	Sept. 2000
 *	Xenia Tkatschow ([e-mail])
 *    2Gb awareness and general cleanup:
 *	Fritz Elfert ([e-mail], [e-mail])
 *    Rewritten for af_iucv:
 *	Martin Schwidefsky <[e-mail]>
 *
 * Documentation used:
 *    The original source
 *    CP Programming Service, IBM document # SC24-5760
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/cpu.h>
#include <net/iucv/iucv.h>
#include <asm/atomic.h>
#include <asm/ebcdic.h>
#include <asm/io.h>
#include <asm/s390_ext.h>
#include <asm/s390_rdev.h>
#include <asm/smp.h>

/*
 * FLAGS:
 * All flags are defined in the field IPFLAGS1 of each function
 * and can be found in CP Programming Services.
 * IPSRCCLS - Indicates you have specified a source class.
 * IPTRGCLS - Indicates you have specified a target class.
 * IPFGPID  - Indicates you have specified a pathid.
 * IPFGMID  - Indicates you have specified a message ID.
 * IPNORPY  - Indicates a one-way message. No reply expected.
 * IPALL    - Indicates that all paths are affected.
 */
#define IUCV_IPSRCCLS	0x01
#define IUCV_IPTRGCLS	0x01
#define IUCV_IPFGPID	0x02
#define IUCV_IPFGMID	0x04
#define IUCV_IPNORPY	0x10
#define IUCV_IPALL	0x80

static int iucv_bus_match(struct device *dev, struct device_driver *drv)
{
	return 0;
}

struct bus_type iucv_bus = {
	.name = "iucv",
	.match = iucv_bus_match,
};
EXPORT_SYMBOL(iucv_bus);

struct device *iucv_root;
EXPORT_SYMBOL(iucv_root);

static int iucv_available;

/* General IUCV interrupt structure */
struct iucv_irq_data {
	u16 ippathid;
	u8  ipflags1;
	u8  iptype;
	u32 res2[8];
};

struct iucv_irq_list {
	struct list_head list;
	struct iucv_irq_data data;
};

static struct iucv_irq_data *iucv_irq_data[NR_CPUS];
static cpumask_t iucv_buffer_cpumask = CPU_MASK_NONE;
static cpumask_t iucv_irq_cpumask = CPU_MASK_NONE;

/*
 * Queue of interrupt buffers lock for delivery via the tasklet
 * (fast but can't call smp_call_function).
 */
static LIST_HEAD(iucv_task_queue);

/*
 * The tasklet for fast delivery of iucv interrupts.
 */
static void iucv_tasklet_fn(unsigned long);
static DECLARE_TASKLET(iucv_tasklet, iucv_tasklet_fn,0);

/*
 * Queue of interrupt buffers for delivery via a work queue
 * (slower but can call smp_call_function).
 */
static LIST_HEAD(iucv_work_queue);

/*
 * The work element to deliver path pending interrupts.
 */
static void iucv_work_fn(struct work_struct *work);
static DECLARE_WORK(iucv_work, iucv_work_fn);

/*
 * Spinlock protecting task and work queue.
 */
static DEFINE_SPINLOCK(iucv_queue_lock);

enum iucv_command_codes {
	IUCV_QUERY = 0,
	IUCV_RETRIEVE_BUFFER = 2,
	IUCV_SEND = 4,
	IUCV_RECEIVE = 5,
	IUCV_REPLY = 6,
	IUCV_REJECT = 8,
	IUCV_PURGE = 9,
	IUCV_ACCEPT = 10,
	IUCV_CONNECT = 11,
	IUCV_DECLARE_BUFFER = 12,
	IUCV_QUIESCE = 13,
	IUCV_RESUME = 14,
	IUCV_SEVER = 15,
	IUCV_SETMASK = 16,
};

/*
 * Error messages that are used with the iucv_sever function. They get
 * converted to EBCDIC.
 */
static char iucv_error_no_listener[16] = "NO LISTENER";
static char iucv_error_no_memory[16] = "NO MEMORY";
static char iucv_error_pathid[16] = "INVALID PATHID";

/*
 * iucv_handler_list: List of registered handlers.
 */
static LIST_HEAD(iucv_handler_list);

/*
 * iucv_path_table: an array of iucv_path structures.
 */
static struct iucv_path **iucv_path_table;
static unsigned long iucv_max_pathid;

/*
 * iucv_lock: spinlock protecting iucv_handler_list and iucv_pathid_table
 */
static DEFINE_SPINLOCK(iucv_table_lock);

/*
 * iucv_active_cpu: contains the number of the cpu executing the tasklet
 * or the work handler. Needed for iucv_path_sever called from tasklet.
 */
static int iucv_active_cpu = -1;

/*
 * Mutex and wait queue for iucv_register/iucv_unregister.
 */
static DEFINE_MUTEX(iucv_register_mutex);

/*
 * Counter for number of non-smp capable handlers.
 */
static int iucv_nonsmp_handler;

/*
 * IUCV control data structure. Used by iucv_path_accept, iucv_path_connect,
 * iucv_path_quiesce and iucv_path_sever.
 */
struct iucv_cmd_control {
	u16 ippathid;
	u8  ipflags1;
	u8  iprcode;
	u16 ipmsglim;
	u16 res1;
	u8  ipvmid[8];
	u8  ipuser[16];
	u8  iptarget[8];
} __attribute__ ((packed,aligned(8)));

/*
 * Data in parameter list iucv structure. Used by iucv_message_send,
 * iucv_message_send2way and iucv_message_reply.
 */
struct iucv_cmd_dpl {
	u16 ippathid;
	u8  ipflags1;
	u8  iprcode;
	u32 ipmsgid;
	u32 iptrgcls;
	u8  iprmmsg[8];
	u32 ipsrccls;
	u32 ipmsgtag;
	u32 ipbfadr2;
	u32 ipbfln2f;
	u32 res;
} __attribute__ ((packed,aligned(8)));

/*
 * Data in buffer iucv structure. Used by iucv_message_receive,
 * iucv_message_reject, iucv_message_send, iucv_message_send2way
 * and iucv_declare_cpu.
 */
struct iucv_cmd_db {
	u16 ippathid;
	u8  ipflags1;
	u8  iprcode;
	u32 ipmsgid;
	u32 iptrgcls;
	u32 ipbfadr1;
	u32 ipbfln1f;
	u32 ipsrccls;
	u32 ipmsgtag;
	u32 ipbfadr2;
	u32 ipbfln2f;
	u32 res;
} __attribute__ ((packed,aligned(8)));

/*
 * Purge message iucv structure. Used by iucv_message_purge.
 */
struct iucv_cmd_purge {
	u16 ippathid;
	u8  ipflags1;
	u8  iprcode;
	u32 ipmsgid;
	u8  ipaudit[3];
	u8  res1[5];
	u32 res2;
	u32 ipsrccls;
	u32 ipmsgtag;
	u32 res3[3];
} __attribute__ ((packed,aligned(8)));

/*
 * Set mask iucv structure. Used by iucv_enable_cpu.
 */
struct iucv_cmd_set_mask {
	u8  ipmask;
	u8  res1[2];
	u8  iprcode;
	u32 res2[9];
} __attribute__ ((packed,aligned(8)));

union iucv_param {
	struct iucv_cmd_control ctrl;
	struct iucv_cmd_dpl dpl;
	struct iucv_cmd_db db;
	struct iucv_cmd_purge purge;
	struct iucv_cmd_set_mask set_mask;
};

/*
 * Anchor for per-cpu IUCV command parameter block.
 */
static union iucv_param *iucv_param[NR_CPUS];

/**
 * iucv_call_b2f0
 * @code: identifier of IUCV call to CP.
 * @parm: pointer to a struct iucv_parm block
 *
 * Calls CP to execute IUCV commands.
 *
 * Returns the result of the CP IUCV call.
 */
static inline int iucv_call_b2f0(int command, union iucv_param *parm)
{
	register unsigned long reg0 asm ("0");
	register unsigned long reg1 asm ("1");
	int ccode;

	reg0 = command;
	reg1 = virt_to_phys(parm);
	asm volatile(
		"	.long 0xb2f01000\n"
		"	ipm	%0\n"
		"	srl	%0,28\n"
		: "=d" (ccode), "=m" (*parm), "+d" (reg0), "+a" (reg1)
		:  "m" (*parm) : "cc");
	return (ccode == 1) ? parm->ctrl.iprcode : ccode;
}

/**
 * iucv_query_maxconn
 *
 * Determines the maximum number of connections that may be established.
 *
 * Returns the maximum number of connections or -EPERM is IUCV is not
 * available.
 */
static int iucv_query_maxconn(void)
{
	register unsigned long reg0 asm ("0");
	register unsigned long reg1 asm ("1");
	void *param;
	int ccode;

	param = kzalloc(sizeof(union iucv_param), GFP_KERNEL|GFP_DMA);
	if (!param)
		return -ENOMEM;
	reg0 = IUCV_QUERY;
	reg1 = (unsigned long) param;
	asm volatile (
		"	.long	0xb2f01000\n"
		"	ipm	%0\n"
		"	srl	%0,28\n"
		: "=d" (ccode), "+d" (reg0), "+d" (reg1) : : "cc");
	if (ccode == 0)
		iucv_max_pathid = reg0;
	kfree(param);
	return ccode ? -EPERM : 0;
}

/**
 * iucv_allow_cpu
 * @data: unused
 *
 * Allow iucv interrupts on this cpu.
 */
static void iucv_allow_cpu(void *data)
{
	int cpu = smp_processor_id();
	union iucv_param *parm;

	/*
	 * Enable all iucv interrupts.
	 * ipmask contains bits for the different interrupts
	 *	0x80 - Flag to allow nonpriority message pending interrupts
	 *	0x40 - Flag to allow priority message pending interrupts
	 *	0x20 - Flag to allow nonpriority message completion interrupts
	 *	0x10 - Flag to allow priority message completion interrupts
	 *	0x08 - Flag to allow IUCV control interrupts
	 */
	parm = iucv_param[cpu];
	memset(parm, 0, sizeof(union iucv_param));
	parm->set_mask.ipmask = 0xf8;
	iucv_call_b2f0(IUCV_SETMASK, parm);

	/* Set indication that iucv interrupts are allowed for this cpu. */
	cpu_set(cpu, iucv_irq_cpumask);
}

/**
 * iucv_block_cpu
 * @data: unused
 *
 * Block iucv interrupts on this cpu.
 */
static void iucv_block_cpu(void *data)
{
	int cpu = smp_processor_id();
	union iucv_param *parm;

	/* Disable all iucv interrupts. */
	parm = iucv_param[cpu];
	memset(parm, 0, sizeof(union iucv_param));
	iucv_call_b2f0(IUCV_SETMASK, parm);

	/* Clear indication that iucv interrupts are allowed for this cpu. */
	cpu_clear(cpu, iucv_irq_cpumask);
}

/**
 * iucv_declare_cpu
 * @data: unused
 *
 * Declare a interrupt buffer on this cpu.
 */
static void iucv_declare_cpu(void *data)
{
	int cpu = smp_processor_id();
	union iucv_param *parm;
	int rc;

	if (cpu_isset(cpu, iucv_buffer_cpumask))
		return;

	/* Declare interrupt buffer. */
	parm = iucv_param[cpu];
	memset(parm, 0, sizeof(union iucv_param));
	parm->db.ipbfadr1 = virt_to_phys(iucv_irq_data[cpu]);
	rc = iucv_call_b2f0(IUCV_DECLARE_BUFFER, parm);
	if (rc) {
		char *err = "Unknown";
		switch (rc) {
		case 0x03:
			err = "Directory error";
			break;
		case 0x0a:
			err = "Invalid length";
			break;
		case 0x13:
			err = "Buffer already exists";
			break;
		case 0x3e:
			err = "Buffer overlap";
			break;
		case 0x5c:
			err = "Paging or storage error";
			break;
		}
		printk(KERN_WARNING "iucv_register: iucv_declare_buffer "
		       "on cpu %i returned error 0x%02x (%s)\n", cpu, rc, err);
		return;
	}

	/* Set indication that an iucv buffer exists for this cpu. */
	cpu_set(cpu, iucv_buffer_cpumask);

	if (iucv_nonsmp_handler == 0 || cpus_empty(iucv_irq_cpumask))
		/* Enable iucv interrupts on this cpu. */
		iucv_allow_cpu(NULL);
	else
		/* Disable iucv interrupts on this cpu. */
		iucv_block_cpu(NULL);
}

/**
 * iucv_retrieve_cpu
 * @data: unused
 *
 * Retrieve interrupt buffer on this cpu.
 */
static void iucv_retrieve_cpu(void *data)
{
	int cpu = smp_processor_id();
	union iucv_param *parm;

	if (!cpu_isset(cpu, iucv_buffer_cpumask))
		return;

	/* Block iucv interrupts. */
	iucv_block_cpu(NULL);

	/* Retrieve interrupt buffer. */
	parm = iucv_param[cpu];
	iucv_call_b2f0(IUCV_RETRIEVE_BUFFER, parm);

	/* Clear indication that an iucv buffer exists for this cpu. */
	cpu_clear(cpu, iucv_buffer_cpumask);
}

/**
 * iucv_setmask_smp
 *
 * Allow iucv interrupts on all cpus.
 */
static void iucv_setmask_mp(void)
{
	int cpu;

	preempt_disable();
	for_each_online_cpu(cpu)
		/* Enable all cpus with a declared buffer. */
		if (cpu_isset(cpu, iucv_buffer_cpumask) &&
		    !cpu_isset(cpu, iucv_irq_cpumask))
			smp_call_function_single(cpu, iucv_allow_cpu,
						 NULL, 0, 1);
	preempt_enable();
}

/**
 * iucv_setmask_up
 *
 * Allow iucv interrupts on a single cpu.
 */
static void iucv_setmask_up(void)
{
	cpumask_t cpumask;
	int cpu;

	/* Disable all cpu but the first in cpu_irq_cpumask. */
	cpumask = iucv_irq_cpumask;
	cpu_clear(first_cpu(iucv_irq_cpumask), cpumask);
	for_each_cpu_mask(cpu, cpumask)
		smp_call_function_single(cpu, iucv_block_cpu, NULL, 0, 1);
}

/**
 * iucv_enable
 *
 * This function makes iucv ready for use. It allocates the pathid
 * table, declares an iucv interrupt buffer and enables the iucv
 * interrupts. Called when the first user has registered an iucv
 * handler.
 */
static int iucv_enable(void)
{
	size_t alloc_size;
	int cpu, rc;

	rc = -ENOMEM;
	alloc_size = iucv_max_pathid * sizeof(struct iucv_path);
	iucv_path_table = kzalloc(alloc_size, GFP_KERNEL);
	if (!iucv_path_table)
		goto out;
	/* Declare per cpu buffers. */
	rc = -EIO;
	preempt_disable();
	for_each_online_cpu(cpu)
		smp_call_function_single(cpu, iucv_declare_cpu, NULL, 0, 1);
	preempt_enable();
	if (cpus_empty(iucv_buffer_cpumask))
		/* No cpu could declare an iucv buffer. */
		goto out_path;
	return 0;

out_path:
	kfree(iucv_path_table);
out:
	return rc;
}

/**
 * iucv_disable
 *
 * This function shuts down iucv. It disables iucv interrupts, retrieves
 * the iucv interrupt buffer and frees the pathid table. Called after the
 * last user unregister its iucv handler.
 */
static void iucv_disable(void)
{
	on_each_cpu(iucv_retrieve_cpu, NULL, 0, 1);
	kfree(iucv_path_table);
}

static int __cpuinit iucv_cpu_notify(struct notifier_block *self,
				     unsigned long action, void *hcpu)
{
	cpumask_t cpumask;
	long cpu = (long) hcpu;

	switch (action) {
	case CPU_UP_PREPARE:
	case CPU_UP_PREPARE_FROZEN:
		iucv_irq_data[cpu] = kmalloc_node(sizeof(struct iucv_irq_data),
					GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
		if (!iucv_irq_data[cpu])
			return NOTIFY_BAD;
		iucv_param[cpu] = kmalloc_node(sizeof(union iucv_param),
				     GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));