Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 813 insertions, 0 deletions

diff --git a/drivers/s390/char/sclp_tty.c b/drivers/s390/char/sclp_tty.c
new file mode 100644
index 000000000000..a20d7c89341d
--- /dev/null
+++ b/drivers/s390/char/sclp_tty.c
@@ -0,0 +1,813 @@
+/*
+ *  drivers/s390/char/sclp_tty.c
+ *    SCLP line mode terminal driver.
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Martin Peschke <mpeschke@de.ibm.com>
+ *               Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <asm/uaccess.h>
+
+#include "ctrlchar.h"
+#include "sclp.h"
+#include "sclp_rw.h"
+#include "sclp_tty.h"
+
+#define SCLP_TTY_PRINT_HEADER "sclp tty driver: "
+
+/*
+ * size of a buffer that collects single characters coming in
+ * via sclp_tty_put_char()
+ */
+#define SCLP_TTY_BUF_SIZE 512
+
+/*
+ * There is exactly one SCLP terminal, so we can keep things simple
+ * and allocate all variables statically.
+ */
+
+/* Lock to guard over changes to global variables. */
+static spinlock_t sclp_tty_lock;
+/* List of free pages that can be used for console output buffering. */
+static struct list_head sclp_tty_pages;
+/* List of full struct sclp_buffer structures ready for output. */
+static struct list_head sclp_tty_outqueue;
+/* Counter how many buffers are emitted. */
+static int sclp_tty_buffer_count;
+/* Pointer to current console buffer. */
+static struct sclp_buffer *sclp_ttybuf;
+/* Timer for delayed output of console messages. */
+static struct timer_list sclp_tty_timer;
+/* Waitqueue to wait for buffers to get empty. */
+static wait_queue_head_t sclp_tty_waitq;
+
+static struct tty_struct *sclp_tty;
+static unsigned char sclp_tty_chars[SCLP_TTY_BUF_SIZE];
+static unsigned short int sclp_tty_chars_count;
+
+struct tty_driver *sclp_tty_driver;
+
+extern struct termios  tty_std_termios;
+
+static struct sclp_ioctls sclp_ioctls;
+static struct sclp_ioctls sclp_ioctls_init =
+{
+        8,                      /* 1 hor. tab. = 8 spaces */
+        0,                      /* no echo of input by this driver */
+        80,                     /* 80 characters/line */
+        1,                      /* write after 1/10 s without final new line */
+        MAX_KMEM_PAGES,         /* quick fix: avoid __alloc_pages */
+        MAX_KMEM_PAGES,         /* take 32/64 pages from kernel memory, */
+        0,                      /* do not convert to lower case */
+        0x6c                    /* to seprate upper and lower case */
+                                /* ('%' in EBCDIC) */
+};
+
+/* This routine is called whenever we try to open a SCLP terminal. */
+static int
+sclp_tty_open(struct tty_struct *tty, struct file *filp)
+{
+        sclp_tty = tty;
+        tty->driver_data = NULL;
+        tty->low_latency = 0;
+        return 0;
+}
+
+/* This routine is called when the SCLP terminal is closed. */
+static void
+sclp_tty_close(struct tty_struct *tty, struct file *filp)
+{
+        if (tty->count > 1)
+                return;
+        sclp_tty = NULL;
+}
+
+/* execute commands to control the i/o behaviour of the SCLP tty at runtime */
+static int
+sclp_tty_ioctl(struct tty_struct *tty, struct file * file,
+               unsigned int cmd, unsigned long arg)
+{
+        unsigned long flags;
+        unsigned int obuf;
+        int check;
+        int rc;
+
+        if (tty->flags & (1 << TTY_IO_ERROR))
+                return -EIO;
+        rc = 0;
+        check = 0;
+        switch (cmd) {
+        case TIOCSCLPSHTAB:
+                /* set width of horizontal tab  */
+                if (get_user(sclp_ioctls.htab, (unsigned short __user *) arg))
+                        rc = -EFAULT;
+                else
+                        check = 1;
+                break;
+        case TIOCSCLPGHTAB:
+                /* get width of horizontal tab  */
+                if (put_user(sclp_ioctls.htab, (unsigned short __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPSECHO:
+                /* enable/disable echo of input */
+                if (get_user(sclp_ioctls.echo, (unsigned char __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPGECHO:
+                /* Is echo of input enabled ?  */
+                if (put_user(sclp_ioctls.echo, (unsigned char __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPSCOLS:
+                /* set number of columns for output  */
+                if (get_user(sclp_ioctls.columns, (unsigned short __user *) arg))
+                        rc = -EFAULT;
+                else
+                        check = 1;
+                break;
+        case TIOCSCLPGCOLS:
+                /* get number of columns for output  */
+                if (put_user(sclp_ioctls.columns, (unsigned short __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPSNL:
+                /* enable/disable writing without final new line character  */
+                if (get_user(sclp_ioctls.final_nl, (signed char __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPGNL:
+                /* Is writing without final new line character enabled ?  */
+                if (put_user(sclp_ioctls.final_nl, (signed char __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPSOBUF:
+                /*
+                 * set the maximum buffers size for output, will be rounded
+                 * up to next 4kB boundary and stored as number of SCCBs
+                 * (4kB Buffers) limitation: 256 x 4kB
+                 */
+                if (get_user(obuf, (unsigned int __user *) arg) == 0) {
+                        if (obuf & 0xFFF)
+                                sclp_ioctls.max_sccb = (obuf >> 12) + 1;
+                        else
+                                sclp_ioctls.max_sccb = (obuf >> 12);
+                } else
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPGOBUF:
+                /* get the maximum buffers size for output  */
+                obuf = sclp_ioctls.max_sccb << 12;
+                if (put_user(obuf, (unsigned int __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPGKBUF:
+                /* get the number of buffers got from kernel at startup */
+                if (put_user(sclp_ioctls.kmem_sccb, (unsigned short __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPSCASE:
+                /* enable/disable conversion from upper to lower case */
+                if (get_user(sclp_ioctls.tolower, (unsigned char __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPGCASE:
+                /* Is conversion from upper to lower case of input enabled? */
+                if (put_user(sclp_ioctls.tolower, (unsigned char __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPSDELIM:
+                /*
+                 * set special character used for separating upper and
+                 * lower case, 0x00 disables this feature
+                 */
+                if (get_user(sclp_ioctls.delim, (unsigned char __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPGDELIM:
+                /*
+                 * get special character used for separating upper and
+                 * lower case, 0x00 disables this feature
+                 */
+                if (put_user(sclp_ioctls.delim, (unsigned char __user *) arg))
+                        rc = -EFAULT;
+                break;
+        case TIOCSCLPSINIT:
+                /* set initial (default) sclp ioctls  */
+                sclp_ioctls = sclp_ioctls_init;
+                check = 1;
+                break;
+        default:
+                rc = -ENOIOCTLCMD;
+                break;
+        }
+        if (check) {
+                spin_lock_irqsave(&sclp_tty_lock, flags);
+                if (sclp_ttybuf != NULL) {
+                        sclp_set_htab(sclp_ttybuf, sclp_ioctls.htab);
+                        sclp_set_columns(sclp_ttybuf, sclp_ioctls.columns);
+                }
+                spin_unlock_irqrestore(&sclp_tty_lock, flags);
+        }
+        return rc;
+}
+
+/*
+ * This routine returns the numbers of characters the tty driver
+ * will accept for queuing to be written.  This number is subject
+ * to change as output buffers get emptied, or if the output flow
+ * control is acted. This is not an exact number because not every
+ * character needs the same space in the sccb. The worst case is
+ * a string of newlines. Every newlines creates a new mto which
+ * needs 8 bytes.
+ */
+static int
+sclp_tty_write_room (struct tty_struct *tty)
+{
+        unsigned long flags;
+        struct list_head *l;
+        int count;
+
+        spin_lock_irqsave(&sclp_tty_lock, flags);
+        count = 0;
+        if (sclp_ttybuf != NULL)
+                count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct mto);
+        list_for_each(l, &sclp_tty_pages)
+                count += NR_EMPTY_MTO_PER_SCCB;
+        spin_unlock_irqrestore(&sclp_tty_lock, flags);
+        return count;
+}
+
+static void
+sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
+{
+        unsigned long flags;
+        void *page;
+
+        do {
+                page = sclp_unmake_buffer(buffer);
+                spin_lock_irqsave(&sclp_tty_lock, flags);
+                /* Remove buffer from outqueue */
+                list_del(&buffer->list);
+                sclp_tty_buffer_count--;
+                list_add_tail((struct list_head *) page, &sclp_tty_pages);
+                /* Check if there is a pending buffer on the out queue. */
+                buffer = NULL;
+                if (!list_empty(&sclp_tty_outqueue))
+                        buffer = list_entry(sclp_tty_outqueue.next,
+                                            struct sclp_buffer, list);
+                spin_unlock_irqrestore(&sclp_tty_lock, flags);
+        } while (buffer && sclp_emit_buffer(buffer, sclp_ttybuf_callback));
+        wake_up(&sclp_tty_waitq);
+        /* check if the tty needs a wake up call */
+        if (sclp_tty != NULL) {
+                tty_wakeup(sclp_tty);
+        }
+}
+
+static inline void
+__sclp_ttybuf_emit(struct sclp_buffer *buffer)
+{
+        unsigned long flags;
+        int count;
+        int rc;
+
+        spin_lock_irqsave(&sclp_tty_lock, flags);
+        list_add_tail(&buffer->list, &sclp_tty_outqueue);
+        count = sclp_tty_buffer_count++;
+        spin_unlock_irqrestore(&sclp_tty_lock, flags);
+        if (count)
+                return;
+        rc = sclp_emit_buffer(buffer, sclp_ttybuf_callback);
+        if (rc)
+                sclp_ttybuf_callback(buffer, rc);
+}
+
+/*
+ * When this routine is called from the timer then we flush the
+ * temporary write buffer.
+ */
+static void
+sclp_tty_timeout(unsigned long data)
+{
+        unsigned long flags;
+        struct sclp_buffer *buf;
+
+        spin_lock_irqsave(&sclp_tty_lock, flags);
+        buf = sclp_ttybuf;
+        sclp_ttybuf = NULL;
+        spin_unlock_irqrestore(&sclp_tty_lock, flags);
+
+        if (buf != NULL) {
+                __sclp_ttybuf_emit(buf);
+        }
+}
+
+/*
+ * Write a string to the sclp tty.
+ */
+static void
+sclp_tty_write_string(const unsigned char *str, int count)
+{
+        unsigned long flags;
+        void *page;
+        int written;
+        struct sclp_buffer *buf;
+
+        if (count <= 0)
+                return;
+        spin_lock_irqsave(&sclp_tty_lock, flags);
+        do {
+                /* Create a sclp output buffer if none exists yet */
+                if (sclp_ttybuf == NULL) {
+                        while (list_empty(&sclp_tty_pages)) {
+                                spin_unlock_irqrestore(&sclp_tty_lock, flags);
+                                if (in_interrupt())
+                                        sclp_sync_wait();
+                                else
+                                        wait_event(sclp_tty_waitq,
+                                                !list_empty(&sclp_tty_pages));
+                                spin_lock_irqsave(&sclp_tty_lock, flags);
+                        }
+                        page = sclp_tty_pages.next;
+                        list_del((struct list_head *) page);
+                        sclp_ttybuf = sclp_make_buffer(page,
+                                                       sclp_ioctls.columns,
+                                                       sclp_ioctls.htab);
+                }
+                /* try to write the string to the current output buffer */
+                written = sclp_write(sclp_ttybuf, str, count);
+                if (written == count)
+                        break;
+                /*
+                 * Not all characters could be written to the current
+                 * output buffer. Emit the buffer, create a new buffer
+                 * and then output the rest of the string.
+                 */
+                buf = sclp_ttybuf;
+                sclp_ttybuf = NULL;
+                spin_unlock_irqrestore(&sclp_tty_lock, flags);
+                __sclp_ttybuf_emit(buf);
+                spin_lock_irqsave(&sclp_tty_lock, flags);
+                str += written;
+                count -= written;
+        } while (count > 0);
+        /* Setup timer to output current console buffer after 1/10 second */
+        if (sclp_ioctls.final_nl) {
+                if (sclp_ttybuf != NULL &&
+                    sclp_chars_in_buffer(sclp_ttybuf) != 0 &&
+                    !timer_pending(&sclp_tty_timer)) {
+                        init_timer(&sclp_tty_timer);
+                        sclp_tty_timer.function = sclp_tty_timeout;
+                        sclp_tty_timer.data = 0UL;
+                        sclp_tty_timer.expires = jiffies + HZ/10;
+                        add_timer(&sclp_tty_timer);
+                }
+        } else {
+                if (sclp_ttybuf != NULL &&
+                    sclp_chars_in_buffer(sclp_ttybuf) != 0) {
+                        buf = sclp_ttybuf;
+                        sclp_ttybuf = NULL;
+                        spin_unlock_irqrestore(&sclp_tty_lock, flags);
+                        __sclp_ttybuf_emit(buf);
+                        spin_lock_irqsave(&sclp_tty_lock, flags);
+                }
+        }
+        spin_unlock_irqrestore(&sclp_tty_lock, flags);
+}
+
+/*
+ * This routine is called by the kernel to write a series of characters to the
+ * tty device. The characters may come from user space or kernel space. This
+ * routine will return the number of characters actually accepted for writing.
+ */
+static int
+sclp_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+        if (sclp_tty_chars_count > 0) {
+                sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
+                sclp_tty_chars_count = 0;
+        }
+        sclp_tty_write_string(buf, count);
+        return count;
+}
+
+/*
+ * This routine is called by the kernel to write a single character to the tty
+ * device. If the kernel uses this routine, it must call the flush_chars()
+ * routine (if defined) when it is done stuffing characters into the driver.
+ *
+ * Characters provided to sclp_tty_put_char() are buffered by the SCLP driver.
+ * If the given character is a '\n' the contents of the SCLP write buffer
+ * - including previous characters from sclp_tty_put_char() and strings from
+ * sclp_write() without final '\n' - will be written.
+ */
+static void
+sclp_tty_put_char(struct tty_struct *tty, unsigned char ch)
+{
+        sclp_tty_chars[sclp_tty_chars_count++] = ch;
+        if (ch == '\n' || sclp_tty_chars_count >= SCLP_TTY_BUF_SIZE) {
+                sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
+                sclp_tty_chars_count = 0;
+        }
+}
+
+/*
+ * This routine is called by the kernel after it has written a series of
+ * characters to the tty device using put_char().
+ */
+static void
+sclp_tty_flush_chars(struct tty_struct *tty)
+{
+        if (sclp_tty_chars_count > 0) {
+                sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
+                sclp_tty_chars_count = 0;
+        }
+}
+
+/*
+ * This routine returns the number of characters in the write buffer of the
+ * SCLP driver. The provided number includes all characters that are stored
+ * in the SCCB (will be written next time the SCLP is not busy) as well as
+ * characters in the write buffer (will not be written as long as there is a
+ * final line feed missing).
+ */
+static int
+sclp_tty_chars_in_buffer(struct tty_struct *tty)
+{
+        unsigned long flags;
+        struct list_head *l;
+        struct sclp_buffer *t;
+        int count;
+
+        spin_lock_irqsave(&sclp_tty_lock, flags);
+        count = 0;
+        if (sclp_ttybuf != NULL)
+                count = sclp_chars_in_buffer(sclp_ttybuf);
+        list_for_each(l, &sclp_tty_outqueue) {
+                t = list_entry(l, struct sclp_buffer, list);
+                count += sclp_chars_in_buffer(t);
+        }
+        spin_unlock_irqrestore(&sclp_tty_lock, flags);
+        return count;
+}
+
+/*
+ * removes all content from buffers of low level driver
+ */
+static void
+sclp_tty_flush_buffer(struct tty_struct *tty)
+{
+        if (sclp_tty_chars_count > 0) {
+                sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
+                sclp_tty_chars_count = 0;
+        }
+}
+
+/*
+ * push input to tty
+ */
+static void
+sclp_tty_input(unsigned char* buf, unsigned int count)
+{
+        unsigned int cchar;
+
+        /*
+         * If this tty driver is currently closed
+         * then throw the received input away.
+         */
+        if (sclp_tty == NULL)
+                return;
+        cchar = ctrlchar_handle(buf, count, sclp_tty);
+        switch (cchar & CTRLCHAR_MASK) {
+        case CTRLCHAR_SYSRQ:
+                break;
+        case CTRLCHAR_CTRL:
+                sclp_tty->flip.count++;
+                *sclp_tty->flip.flag_buf_ptr++ = TTY_NORMAL;
+                *sclp_tty->flip.char_buf_ptr++ = cchar;
+                tty_flip_buffer_push(sclp_tty);
+                break;
+        case CTRLCHAR_NONE:
+                /* send (normal) input to line discipline */
+                memcpy(sclp_tty->flip.char_buf_ptr, buf, count);
+                if (count < 2 ||
+                    (strncmp ((const char *) buf + count - 2, "^n", 2) &&
+                     strncmp ((const char *) buf + count - 2, "\0252n", 2))) {
+                        sclp_tty->flip.char_buf_ptr[count] = '\n';
+                        count++;
+                } else
+                        count -= 2;
+                memset(sclp_tty->flip.flag_buf_ptr, TTY_NORMAL, count);
+                sclp_tty->flip.char_buf_ptr += count;
+                sclp_tty->flip.flag_buf_ptr += count;
+                sclp_tty->flip.count += count;
+                tty_flip_buffer_push(sclp_tty);
+                break;
+        }
+}
+
+/*
+ * get a EBCDIC string in upper/lower case,
+ * find out characters in lower/upper case separated by a special character,
+ * modifiy original string,
+ * returns length of resulting string
+ */
+static int
+sclp_switch_cases(unsigned char *buf, int count,
+                  unsigned char delim, int tolower)
+{
+        unsigned char *ip, *op;
+        int toggle;
+
+        /* initially changing case is off */
+        toggle = 0;
+        ip = op = buf;
+        while (count-- > 0) {
+                /* compare with special character */
+                if (*ip == delim) {
+                        /* followed by another special character? */
+                        if (count && ip[1] == delim) {
+                                /*
+                                 * ... then put a single copy of the special
+                                 * character to the output string
+                                 */
+                                *op++ = *ip++;
+                                count--;
+                        } else
+                                /*
+                                 * ... special character follower by a normal
+                                 * character toggles the case change behaviour
+                                 */
+                                toggle = ~toggle;
+                        /* skip special character */
+                        ip++;
+                } else
+                        /* not the special character */
+                        if (toggle)
+                                /* but case switching is on */
+                                if (tolower)
+                                        /* switch to uppercase */
+                                        *op++ = _ebc_toupper[(int) *ip++];
+                                else
+                                        /* switch to lowercase */
+                                        *op++ = _ebc_tolower[(int) *ip++];
+                        else
+                                /* no case switching, copy the character */
+                                *op++ = *ip++;
+        }
+        /* return length of reformatted string. */
+        return op - buf;
+}
+
+static void
+sclp_get_input(unsigned char *start, unsigned char *end)
+{
+        int count;
+
+        count = end - start;
+        /*
+         * if set in ioctl convert EBCDIC to lower case
+         * (modify original input in SCCB)
+         */
+        if (sclp_ioctls.tolower)
+                EBC_TOLOWER(start, count);
+
+        /*
+         * if set in ioctl find out characters in lower or upper case
+         * (depends on current case) separated by a special character,
+         * works on EBCDIC
+         */
+        if (sclp_ioctls.delim)
+                count = sclp_switch_cases(start, count,
+                                          sclp_ioctls.delim,
+                                          sclp_ioctls.tolower);
+
+        /* convert EBCDIC to ASCII (modify original input in SCCB) */
+        sclp_ebcasc_str(start, count);
+
+        /* if set in ioctl write operators input to console  */
+        if (sclp_ioctls.echo)
+                sclp_tty_write(sclp_tty, start, count);
+
+        /* transfer input to high level driver */
+        sclp_tty_input(start, count);
+}
+
+static inline struct gds_vector *
+find_gds_vector(struct gds_vector *start, struct gds_vector *end, u16 id)
+{
+        struct gds_vector *vec;
+
+        for (vec = start; vec < end; vec = (void *) vec + vec->length)
+                if (vec->gds_id == id)
+                        return vec;
+        return NULL;
+}
+
+static inline struct gds_subvector *
+find_gds_subvector(struct gds_subvector *start,
+                   struct gds_subvector *end, u8 key)
+{
+        struct gds_subvector *subvec;
+
+        for (subvec = start; subvec < end;
+             subvec = (void *) subvec + subvec->length)
+                if (subvec->key == key)
+                        return subvec;
+        return NULL;
+}
+
+static inline void
+sclp_eval_selfdeftextmsg(struct gds_subvector *start,
+                         struct gds_subvector *end)
+{
+        struct gds_subvector *subvec;
+
+        subvec = start;
+        while (subvec < end) {
+                subvec = find_gds_subvector(subvec, end, 0x30);
+                if (!subvec)
+                        break;
+                sclp_get_input((unsigned char *)(subvec + 1),
+                               (unsigned char *) subvec + subvec->length);
+                subvec = (void *) subvec + subvec->length;
+        }
+}
+
+static inline void
+sclp_eval_textcmd(struct gds_subvector *start,
+                  struct gds_subvector *end)
+{
+        struct gds_subvector *subvec;
+
+        subvec = start;
+        while (subvec < end) {
+                subvec = find_gds_subvector(subvec, end,
+                                            GDS_KEY_SelfDefTextMsg);
+                if (!subvec)
+                        break;
+                sclp_eval_selfdeftextmsg((struct gds_subvector *)(subvec + 1),
+                                         (void *)subvec + subvec->length);
+                subvec = (void *) subvec + subvec->length;
+        }
+}
+
+static inline void
+sclp_eval_cpmsu(struct gds_vector *start, struct gds_vector *end)
+{
+        struct gds_vector *vec;
+
+        vec = start;
+        while (vec < end) {
+                vec = find_gds_vector(vec, end, GDS_ID_TextCmd);
+                if (!vec)
+                        break;
+                sclp_eval_textcmd((struct gds_subvector *)(vec + 1),
+                                  (void *) vec + vec->length);
+                vec = (void *) vec + vec->length;
+        }
+}
+
+
+static inline void
+sclp_eval_mdsmu(struct gds_vector *start, void *end)
+{
+        struct gds_vector *vec;
+
+        vec = find_gds_vector(start, end, GDS_ID_CPMSU);
+        if (vec)
+                sclp_eval_cpmsu(vec + 1, (void *) vec + vec->length);
+}
+
+static void
+sclp_tty_receiver(struct evbuf_header *evbuf)
+{
+        struct gds_vector *start, *end, *vec;
+
+        start = (struct gds_vector *)(evbuf + 1);
+        end = (void *) evbuf + evbuf->length;
+        vec = find_gds_vector(start, end, GDS_ID_MDSMU);
+        if (vec)
+                sclp_eval_mdsmu(vec + 1, (void *) vec + vec->length);
+}
+
+static void
+sclp_tty_state_change(struct sclp_register *reg)
+{
+}
+
+static struct sclp_register sclp_input_event =
+{
+        .receive_mask = EvTyp_OpCmd_Mask | EvTyp_PMsgCmd_Mask,
+        .state_change_fn = sclp_tty_state_change,
+        .receiver_fn = sclp_tty_receiver
+};
+
+static struct tty_operations sclp_ops = {
+        .open = sclp_tty_open,
+        .close = sclp_tty_close,
+        .write = sclp_tty_write,
+        .put_char = sclp_tty_put_char,
+        .flush_chars = sclp_tty_flush_chars,
+        .write_room = sclp_tty_write_room,
+        .chars_in_buffer = sclp_tty_chars_in_buffer,
+        .flush_buffer = sclp_tty_flush_buffer,
+        .ioctl = sclp_tty_ioctl,
+};
+
+int __init
+sclp_tty_init(void)
+{
+        struct tty_driver *driver;
+        void *page;
+        int i;
+        int rc;
+
+        if (!CONSOLE_IS_SCLP)
+                return 0;
+        driver = alloc_tty_driver(1);
+        if (!driver)
+                return -ENOMEM;
+
+        rc = sclp_rw_init();
+        if (rc) {
+                printk(KERN_ERR SCLP_TTY_PRINT_HEADER
+                       "could not register tty - "
+                       "sclp_rw_init returned %d\n", rc);
+                put_tty_driver(driver);
+                return rc;
+        }
+        /* Allocate pages for output buffering */
+        INIT_LIST_HEAD(&sclp_tty_pages);
+        for (i = 0; i < MAX_KMEM_PAGES; i++) {
+                page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+                if (page == NULL) {
+                        put_tty_driver(driver);
+                        return -ENOMEM;
+                }
+                list_add_tail((struct list_head *) page, &sclp_tty_pages);
+        }
+        INIT_LIST_HEAD(&sclp_tty_outqueue);
+        spin_lock_init(&sclp_tty_lock);
+        init_waitqueue_head(&sclp_tty_waitq);
+        init_timer(&sclp_tty_timer);
+        sclp_ttybuf = NULL;
+        sclp_tty_buffer_count = 0;
+        if (MACHINE_IS_VM) {
+                /*
+                 * save 4 characters for the CPU number
+                 * written at start of each line by VM/CP
+                 */
+                sclp_ioctls_init.columns = 76;
+                /* case input lines to lowercase */
+                sclp_ioctls_init.tolower = 1;
+        }
+        sclp_ioctls = sclp_ioctls_init;
+        sclp_tty_chars_count = 0;
+        sclp_tty = NULL;
+
+        rc = sclp_register(&sclp_input_event);
+        if (rc) {
+                put_tty_driver(driver);
+                return rc;
+        }
+
+        driver->owner = THIS_MODULE;
+        driver->driver_name = "sclp_line";
+        driver->name = "sclp_line";
+        driver->major = TTY_MAJOR;
+        driver->minor_start = 64;
+        driver->type = TTY_DRIVER_TYPE_SYSTEM;
+        driver->subtype = SYSTEM_TYPE_TTY;
+        driver->init_termios = tty_std_termios;
+        driver->init_termios.c_iflag = IGNBRK | IGNPAR;
+        driver->init_termios.c_oflag = ONLCR | XTABS;
+        driver->init_termios.c_lflag = ISIG | ECHO;
+        driver->flags = TTY_DRIVER_REAL_RAW;
+        tty_set_operations(driver, &sclp_ops);
+        rc = tty_register_driver(driver);
+        if (rc) {
+                printk(KERN_ERR SCLP_TTY_PRINT_HEADER
+                       "could not register tty - "
+                       "tty_register_driver returned %d\n", rc);
+                put_tty_driver(driver);
+                return rc;
+        }
+        sclp_tty_driver = driver;
+        return 0;
+}
+module_init(sclp_tty_init);