monreader.c

linux-2.6.15.6

/*
 * drivers/s390/char/monreader.c
 *
 * Character device driver for reading z/VM *MONITOR service records.
 *
 * Copyright (C) 2004 IBM Corporation, IBM Deutschland Entwicklung GmbH.
 *
 * Author: Gerald Schaefer <[e-mail]>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/ctype.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <asm/ebcdic.h>
#include <asm/extmem.h>
#include <linux/poll.h>
#include "../net/iucv.h"


//#define MON_DEBUG			/* Debug messages on/off */

#define MON_NAME "monreader"

#define P_INFO(x...)	printk(KERN_INFO MON_NAME " info: " x)
#define P_ERROR(x...)	printk(KERN_ERR MON_NAME " error: " x)
#define P_WARNING(x...)	printk(KERN_WARNING MON_NAME " warning: " x)

#ifdef MON_DEBUG
#define P_DEBUG(x...)   printk(KERN_DEBUG MON_NAME " debug: " x)
#else
#define P_DEBUG(x...)   do {} while (0)
#endif

#define MON_COLLECT_SAMPLE 0x80
#define MON_COLLECT_EVENT  0x40
#define MON_SERVICE	   "*MONITOR"
#define MON_IN_USE	   0x01
#define MON_MSGLIM	   255

static char mon_dcss_name[9] = "MONDCSS\0";

struct mon_msg {
	u32 pos;
	u32 mca_offset;
	iucv_MessagePending local_eib;
	char msglim_reached;
	char replied_msglim;
};

struct mon_private {
	u16 pathid;
	iucv_handle_t iucv_handle;
	struct mon_msg *msg_array[MON_MSGLIM];
	unsigned int   write_index;
	unsigned int   read_index;
	atomic_t msglim_count;
	atomic_t read_ready;
	atomic_t iucv_connected;
	atomic_t iucv_severed;
};

static unsigned long mon_in_use = 0;

static unsigned long mon_dcss_start;
static unsigned long mon_dcss_end;

static DECLARE_WAIT_QUEUE_HEAD(mon_read_wait_queue);
static DECLARE_WAIT_QUEUE_HEAD(mon_conn_wait_queue);

static u8 iucv_host[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

static u8 user_data_connect[16] = {
	/* Version code, must be 0x01 for shared mode */
	0x01,
	/* what to collect */
	MON_COLLECT_SAMPLE | MON_COLLECT_EVENT,
	/* DCSS name in EBCDIC, 8 bytes padded with blanks */
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};

static u8 user_data_sever[16] = {
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};


/******************************************************************************
 *                             helper functions                               *
 *****************************************************************************/
/*
 * Create the 8 bytes EBCDIC DCSS segment name from
 * an ASCII name, incl. padding
 */
static inline void
dcss_mkname(char *ascii_name, char *ebcdic_name)
{
	int i;

	for (i = 0; i < 8; i++) {
		if (ascii_name[i] == '\0')
			break;
		ebcdic_name[i] = toupper(ascii_name[i]);
	};
	for (; i < 8; i++)
		ebcdic_name[i] = ' ';
	ASCEBC(ebcdic_name, 8);
}

/*
 * print appropriate error message for segment_load()/segment_type()
 * return code
 */
static void
mon_segment_warn(int rc, char* seg_name)
{
	switch (rc) {
	case -ENOENT:
		P_WARNING("cannot load/query segment %s, does not exist\n",
			  seg_name);
		break;
	case -ENOSYS:
		P_WARNING("cannot load/query segment %s, not running on VM\n",
			  seg_name);
		break;
	case -EIO:
		P_WARNING("cannot load/query segment %s, hardware error\n",
			  seg_name);
		break;
	case -ENOTSUPP:
		P_WARNING("cannot load/query segment %s, is a multi-part "
			  "segment\n", seg_name);
		break;
	case -ENOSPC:
		P_WARNING("cannot load/query segment %s, overlaps with "
			  "storage\n", seg_name);
		break;
	case -EBUSY:
		P_WARNING("cannot load/query segment %s, overlaps with "
			  "already loaded dcss\n", seg_name);
		break;
	case -EPERM:
		P_WARNING("cannot load/query segment %s, already loaded in "
			  "incompatible mode\n", seg_name);
		break;
	case -ENOMEM:
		P_WARNING("cannot load/query segment %s, out of memory\n",
			  seg_name);
		break;
	case -ERANGE:
		P_WARNING("cannot load/query segment %s, exceeds kernel "
			  "mapping range\n", seg_name);
		break;
	default:
		P_WARNING("cannot load/query segment %s, return value %i\n",
			  seg_name, rc);
		break;
	}
}

static inline unsigned long
mon_mca_start(struct mon_msg *monmsg)
{
	return monmsg->local_eib.ln1msg1.iprmmsg1_u32;
}

static inline unsigned long
mon_mca_end(struct mon_msg *monmsg)
{
	return monmsg->local_eib.ln1msg2.ipbfln1f;
}

static inline u8
mon_mca_type(struct mon_msg *monmsg, u8 index)
{
	return *((u8 *) mon_mca_start(monmsg) + monmsg->mca_offset + index);
}

static inline u32
mon_mca_size(struct mon_msg *monmsg)
{
	return mon_mca_end(monmsg) - mon_mca_start(monmsg) + 1;
}

static inline u32
mon_rec_start(struct mon_msg *monmsg)
{
	return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 4));
}

static inline u32
mon_rec_end(struct mon_msg *monmsg)
{
	return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 8));
}

static inline int
mon_check_mca(struct mon_msg *monmsg)
{
	if ((mon_rec_end(monmsg) <= mon_rec_start(monmsg)) ||
	    (mon_rec_start(monmsg) < mon_dcss_start) ||
	    (mon_rec_end(monmsg) > mon_dcss_end) ||
	    (mon_mca_type(monmsg, 0) == 0) ||
	    (mon_mca_size(monmsg) % 12 != 0) ||
	    (mon_mca_end(monmsg) <= mon_mca_start(monmsg)) ||
	    (mon_mca_end(monmsg) > mon_dcss_end) ||
	    (mon_mca_start(monmsg) < mon_dcss_start) ||
	    ((mon_mca_type(monmsg, 1) == 0) && (mon_mca_type(monmsg, 2) == 0)))
	{
		P_DEBUG("READ, IGNORED INVALID MCA\n\n");
		return -EINVAL;
	}
	return 0;
}

static inline int
mon_send_reply(struct mon_msg *monmsg, struct mon_private *monpriv)
{
	u8 prmmsg[8];
	int rc;

	P_DEBUG("read, REPLY: pathid = 0x%04X, msgid = 0x%08X, trgcls = "
		"0x%08X\n\n",
		monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid,
		monmsg->local_eib.iptrgcls);
	rc = iucv_reply_prmmsg(monmsg->local_eib.ippathid,
				monmsg->local_eib.ipmsgid,
				monmsg->local_eib.iptrgcls,
				0, prmmsg);
	atomic_dec(&monpriv->msglim_count);
	if (likely(!monmsg->msglim_reached)) {
		monmsg->pos = 0;
		monmsg->mca_offset = 0;
		monpriv->read_index = (monpriv->read_index + 1) %
				      MON_MSGLIM;
		atomic_dec(&monpriv->read_ready);
	} else
		monmsg->replied_msglim = 1;
	if (rc) {
		P_ERROR("read, IUCV reply failed with rc = %i\n\n", rc);
		return -EIO;
	}
	return 0;
}

static inline struct mon_private *
mon_alloc_mem(void)
{
	int i,j;
	struct mon_private *monpriv;

	monpriv = kmalloc(sizeof(struct mon_private), GFP_KERNEL);
	if (!monpriv) {
		P_ERROR("no memory for monpriv\n");
		return NULL;
	}
	memset(monpriv, 0, sizeof(struct mon_private));
	for (i = 0; i < MON_MSGLIM; i++) {
		monpriv->msg_array[i] = kmalloc(sizeof(struct mon_msg),
						    GFP_KERNEL);
		if (!monpriv->msg_array[i]) {
			P_ERROR("open, no memory for msg_array\n");
			for (j = 0; j < i; j++)
				kfree(monpriv->msg_array[j]);
			return NULL;
		}
		memset(monpriv->msg_array[i], 0, sizeof(struct mon_msg));
	}
	return monpriv;
}

static inline void
mon_read_debug(struct mon_msg *monmsg, struct mon_private *monpriv)
{
#ifdef MON_DEBUG
	u8 msg_type[2], mca_type;
	unsigned long records_len;

	records_len = mon_rec_end(monmsg) - mon_rec_start(monmsg) + 1;

	memcpy(msg_type, &monmsg->local_eib.iptrgcls, 2);
	EBCASC(msg_type, 2);
	mca_type = mon_mca_type(monmsg, 0);
	EBCASC(&mca_type, 1);

	P_DEBUG("read, mon_read_index = %i, mon_write_index = %i\n",
		monpriv->read_index, monpriv->write_index);
	P_DEBUG("read, pathid = 0x%04X, msgid = 0x%08X, trgcls = 0x%08X\n",
		monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid,
		monmsg->local_eib.iptrgcls);
	P_DEBUG("read, msg_type = '%c%c', mca_type = '%c' / 0x%X / 0x%X\n",
		msg_type[0], msg_type[1], mca_type ? mca_type : 'X',
		mon_mca_type(monmsg, 1), mon_mca_type(monmsg, 2));
	P_DEBUG("read, MCA: start = 0x%lX, end = 0x%lX\n",
		mon_mca_start(monmsg), mon_mca_end(monmsg));
	P_DEBUG("read, REC: start = 0x%X, end = 0x%X, len = %lu\n\n",
		mon_rec_start(monmsg), mon_rec_end(monmsg), records_len);
	if (mon_mca_size(monmsg) > 12)
		P_DEBUG("READ, MORE THAN ONE MCA\n\n");
#endif
}

static inline void
mon_next_mca(struct mon_msg *monmsg)
{
	if (likely((mon_mca_size(monmsg) - monmsg->mca_offset) == 12))
		return;
	P_DEBUG("READ, NEXT MCA\n\n");
	monmsg->mca_offset += 12;
	monmsg->pos = 0;
}

static inline struct mon_msg *
mon_next_message(struct mon_private *monpriv)
{
	struct mon_msg *monmsg;

	if (!atomic_read(&monpriv->read_ready))
		return NULL;
	monmsg = monpriv->msg_array[monpriv->read_index];
	if (unlikely(monmsg->replied_msglim)) {
		monmsg->replied_msglim = 0;
		monmsg->msglim_reached = 0;
		monmsg->pos = 0;