--- /dev/null
+/*
+ * 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 <geraldsc@de.ibm.com>
+ */
+
+#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);
+}
+
+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;
+ 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;
+ P_WARNING("read, message limit reached\n");
+ monpriv->read_index = (monpriv->read_index + 1) %
+ MON_MSGLIM;
+ atomic_dec(&monpriv->read_ready);
+ return ERR_PTR(-EOVERFLOW);
+ }
+ return monmsg;
+}
+
+
+/******************************************************************************
+ * IUCV handler *
+ *****************************************************************************/
+static void
+mon_iucv_ConnectionComplete(iucv_ConnectionComplete *eib, void *pgm_data)
+{
+ struct mon_private *monpriv = (struct mon_private *) pgm_data;
+
+ P_DEBUG("IUCV connection completed\n");
+ P_DEBUG("IUCV ACCEPT (from *MONITOR): Version = 0x%02X, Event = "
+ "0x%02X, Sample = 0x%02X\n",
+ eib->ipuser[0], eib->ipuser[1], eib->ipuser[2]);
+ atomic_set(&monpriv->iucv_connected, 1);
+ wake_up(&mon_conn_wait_queue);
+}
+
+static void
+mon_iucv_ConnectionSevered(iucv_ConnectionSevered *eib, void *pgm_data)
+{
+ struct mon_private *monpriv = (struct mon_private *) pgm_data;
+
+ P_ERROR("IUCV connection severed with rc = 0x%X\n",
+ (u8) eib->ipuser[0]);
+ atomic_set(&monpriv->iucv_severed, 1);
+ wake_up(&mon_conn_wait_queue);
+ wake_up_interruptible(&mon_read_wait_queue);
+}
+
+static void
+mon_iucv_MessagePending(iucv_MessagePending *eib, void *pgm_data)
+{
+ struct mon_private *monpriv = (struct mon_private *) pgm_data;
+
+ P_DEBUG("IUCV message pending\n");
+ memcpy(&monpriv->msg_array[monpriv->write_index]->local_eib, eib,
+ sizeof(iucv_MessagePending));
+ if (atomic_inc_return(&monpriv->msglim_count) == MON_MSGLIM) {
+ P_WARNING("IUCV message pending, message limit (%i) reached\n",
+ MON_MSGLIM);
+ monpriv->msg_array[monpriv->write_index]->msglim_reached = 1;
+ }
+ monpriv->write_index = (monpriv->write_index + 1) % MON_MSGLIM;
+ atomic_inc(&monpriv->read_ready);
+ wake_up_interruptible(&mon_read_wait_queue);
+}
+
+static iucv_interrupt_ops_t mon_iucvops = {
+ .ConnectionComplete = mon_iucv_ConnectionComplete,
+ .ConnectionSevered = mon_iucv_ConnectionSevered,
+ .MessagePending = mon_iucv_MessagePending,
+};
+
+/******************************************************************************
+ * file operations *
+ *****************************************************************************/
+static int
+mon_open(struct inode *inode, struct file *filp)
+{
+ int rc, i;
+ struct mon_private *monpriv;
+
+ /*
+ * only one user allowed
+ */
+ if (test_and_set_bit(MON_IN_USE, &mon_in_use))
+ return -EBUSY;
+
+ monpriv = mon_alloc_mem();
+ if (!monpriv)
+ return -ENOMEM;
+
+ /*
+ * Register with IUCV and connect to *MONITOR service
+ */
+ monpriv->iucv_handle = iucv_register_program("my_monreader ",
+ MON_SERVICE,
+ NULL,
+ &mon_iucvops,
+ monpriv);
+ if (!monpriv->iucv_handle) {
+ P_ERROR("failed to register with iucv driver\n");
+ rc = -EIO;
+ goto out_error;
+ }
+ P_INFO("open, registered with IUCV\n");
+
+ rc = iucv_connect(&monpriv->pathid, MON_MSGLIM, user_data_connect,
+ MON_SERVICE, iucv_host, IPRMDATA, NULL, NULL,
+ monpriv->iucv_handle, NULL);
+ if (rc) {
+ P_ERROR("iucv connection to *MONITOR failed with "
+ "IPUSER SEVER code = %i\n", rc);
+ rc = -EIO;
+ goto out_unregister;
+ }
+ /*
+ * Wait for connection confirmation
+ */
+ wait_event(mon_conn_wait_queue,
+ atomic_read(&monpriv->iucv_connected) ||
+ atomic_read(&monpriv->iucv_severed));
+ if (atomic_read(&monpriv->iucv_severed)) {
+ atomic_set(&monpriv->iucv_severed, 0);
+ atomic_set(&monpriv->iucv_connected, 0);
+ rc = -EIO;
+ goto out_unregister;
+ }
+ P_INFO("open, established connection to *MONITOR service\n\n");
+ filp->private_data = monpriv;
+ return 0;
+
+out_unregister:
+ iucv_unregister_program(monpriv->iucv_handle);
+out_error:
+ for (i = 0; i < MON_MSGLIM; i++)
+ kfree(monpriv->msg_array[i]);
+ kfree(monpriv);
+ clear_bit(MON_IN_USE, &mon_in_use);
+ return rc;
+}
+
+static int
+mon_close(struct inode *inode, struct file *filp)
+{
+ int rc, i;
+ struct mon_private *monpriv = filp->private_data;
+
+ /*
+ * Close IUCV connection and unregister
+ */
+ rc = iucv_sever(monpriv->pathid, user_data_sever);
+ if (rc)
+ P_ERROR("close, iucv_sever failed with rc = %i\n", rc);
+ else
+ P_INFO("close, terminated connection to *MONITOR service\n");
+
+ rc = iucv_unregister_program(monpriv->iucv_handle);
+ if (rc)
+ P_ERROR("close, iucv_unregister failed with rc = %i\n", rc);
+ else
+ P_INFO("close, unregistered with IUCV\n");
+
+ atomic_set(&monpriv->iucv_severed, 0);
+ atomic_set(&monpriv->iucv_connected, 0);
+ atomic_set(&monpriv->read_ready, 0);
+ atomic_set(&monpriv->msglim_count, 0);
+ monpriv->write_index = 0;
+ monpriv->read_index = 0;
+
+ for (i = 0; i < MON_MSGLIM; i++)
+ kfree(monpriv->msg_array[i]);
+ kfree(monpriv);
+ clear_bit(MON_IN_USE, &mon_in_use);
+ return 0;
+}
+
+static ssize_t
+mon_read(struct file *filp, char __user *data, size_t count, loff_t *ppos)
+{
+ struct mon_private *monpriv = filp->private_data;
+ struct mon_msg *monmsg;
+ int ret;
+
+ monmsg = mon_next_message(monpriv);
+ if (IS_ERR(monmsg))
+ return PTR_ERR(monmsg);
+
+ if (!monmsg) {
+ if (filp->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+ ret = wait_event_interruptible(mon_read_wait_queue,
+ atomic_read(&monpriv->read_ready) ||
+ atomic_read(&monpriv->iucv_severed));
+ if (ret)
+ return ret;
+ if (unlikely(atomic_read(&monpriv->iucv_severed)))
+ return -EIO;
+ monmsg = monpriv->msg_array[monpriv->read_index];
+ }
+
+ if (!monmsg->pos) {
+ monmsg->pos = mon_rec_start(monmsg);
+ mon_read_debug(monmsg, monpriv);
+ }
+ if (mon_check_mca(monmsg))
+ goto reply;
+
+ if (mon_rec_end(monmsg) > monmsg->pos) {
+ count = min(count, (size_t) mon_rec_end(monmsg) - monmsg->pos
+ + 1);
+ ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
+ count);
+ if (ret)
+ return -EFAULT;
+ monmsg->pos += count;
+ *ppos += count;
+ if (mon_rec_end(monmsg) == monmsg->pos)
+ mon_next_mca(monmsg);
+ return count;
+ }
+reply:
+ ret = mon_send_reply(monmsg, monpriv);
+ return ret;
+}
+
+static unsigned int
+mon_poll(struct file *filp, struct poll_table_struct *p)
+{
+ struct mon_private *monpriv = filp->private_data;
+
+ poll_wait(filp, &mon_read_wait_queue, p);
+ if (unlikely(atomic_read(&monpriv->iucv_severed)))
+ return POLLERR;
+ if (atomic_read(&monpriv->read_ready))
+ return POLLIN | POLLRDNORM;
+ return 0;
+}
+
+static struct file_operations mon_fops = {
+ .owner = THIS_MODULE,
+ .open = &mon_open,
+ .release = &mon_close,
+ .read = &mon_read,
+ .poll = &mon_poll,
+};
+
+static struct miscdevice mon_dev = {
+ .name = "monreader",
+ .devfs_name = "monreader",
+ .fops = &mon_fops,
+ .minor = MISC_DYNAMIC_MINOR,
+};
+
+/******************************************************************************
+ * module init/exit *
+ *****************************************************************************/
+static int __init
+mon_init(void)
+{
+ int rc;
+
+ if (!MACHINE_IS_VM) {
+ P_ERROR("not running under z/VM, driver not loaded\n");
+ return -ENODEV;
+ }
+
+ rc = segment_load(mon_dcss_name, SEGMENT_SHARED_RO,
+ &mon_dcss_start, &mon_dcss_end);
+ if (rc < 0) {
+ P_ERROR("Segment %s not loaded, rc = %d\n", mon_dcss_name, rc);
+ return -EINVAL;
+ }
+ dcss_mkname(mon_dcss_name, &user_data_connect[8]);
+
+ rc = misc_register(&mon_dev);
+ if (rc < 0 ) {
+ P_ERROR("misc_register failed, rc = %i\n", rc);
+ goto out;
+ }
+ P_INFO("Loaded segment %s from %p to %p, size = %lu Byte\n",
+ mon_dcss_name, (void *) mon_dcss_start, (void *) mon_dcss_end,
+ mon_dcss_end - mon_dcss_start + 1);
+ return 0;
+
+out:
+ segment_unload(mon_dcss_name);
+ return rc;
+}
+
+static void __exit
+mon_exit(void)
+{
+ segment_unload(mon_dcss_name);
+ WARN_ON(misc_deregister(&mon_dev) != 0);
+ return;
+}
+
+
+module_init(mon_init);
+module_exit(mon_exit);
+
+module_param_string(mondcss, mon_dcss_name, 9, 0444);
+MODULE_PARM_DESC(mondcss, "Name of DCSS segment to be used for *MONITOR "
+ "service, max. 8 chars. Default is MONDCSS");
+
+MODULE_AUTHOR("Gerald Schaefer <geraldsc@de.ibm.com>");
+MODULE_DESCRIPTION("Character device driver for reading z/VM "
+ "monitor service records.");
+MODULE_LICENSE("GPL");
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