1 files changed, 662 insertions, 0 deletions

diff --git a/drivers/s390/char/monreader.c b/drivers/s390/char/monreader.c
new file mode 100644
index 000000000000..5fd3ad867386
--- /dev/null
+++ b/drivers/s390/char/monreader.c
@@ -0,0 +1,662 @@
+/*
+ * 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);
+}
+
+/*
+ * 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;
+                monmsg->mca_offset = 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 nonseekable_open(inode, filp);
+
+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;
+        u32 mce_start;
+
+        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_mca_start(monmsg) + monmsg->mca_offset;
+                mon_read_debug(monmsg, monpriv);
+        }
+        if (mon_check_mca(monmsg))
+                goto reply;
+
+        /* read monitor control element (12 bytes) first */
+        mce_start = mon_mca_start(monmsg) + monmsg->mca_offset;
+        if ((monmsg->pos >= mce_start) && (monmsg->pos < mce_start + 12)) {
+                count = min(count, (size_t) mce_start + 12 - monmsg->pos);
+                ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos,
+                                   count);
+                if (ret)
+                        return -EFAULT;
+                monmsg->pos += count;
+                if (monmsg->pos == mce_start + 12)
+                        monmsg->pos = mon_rec_start(monmsg);
+                goto out_copy;
+        }
+
+        /* read records */
+        if (monmsg->pos <= mon_rec_end(monmsg)) {
+                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;
+                if (monmsg->pos > mon_rec_end(monmsg))
+                        mon_next_mca(monmsg);
+                goto out_copy;
+        }
+reply:
+        ret = mon_send_reply(monmsg, monpriv);
+        return ret;
+
+out_copy:
+        *ppos += count;
+        return count;
+}
+
+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_type(mon_dcss_name);
+        if (rc < 0) {
+                mon_segment_warn(rc, mon_dcss_name);
+                return rc;
+        }
+        if (rc != SEG_TYPE_SC) {
+                P_ERROR("segment %s has unsupported type, should be SC\n",
+                        mon_dcss_name);
+                return -EINVAL;
+        }
+
+        rc = segment_load(mon_dcss_name, SEGMENT_SHARED,
+                          &mon_dcss_start, &mon_dcss_end);
+        if (rc < 0) {
+                mon_segment_warn(rc, mon_dcss_name);
+                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");