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, 785 insertions, 0 deletions

diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
new file mode 100644
index 000000000000..06bd85824d7b
--- /dev/null
+++ b/drivers/s390/char/sclp_vt220.c
@@ -0,0 +1,785 @@
+/*
+ *  drivers/s390/char/sclp_vt220.c
+ *    SCLP VT220 terminal driver.
+ *
+ *  S390 version
+ *    Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+#include <linux/timer.h>
+#include <linux/kernel.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/major.h>
+#include <linux/console.h>
+#include <linux/kdev_t.h>
+#include <linux/bootmem.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include "sclp.h"
+
+#define SCLP_VT220_PRINT_HEADER         "sclp vt220 tty driver: "
+#define SCLP_VT220_MAJOR                TTY_MAJOR
+#define SCLP_VT220_MINOR                65
+#define SCLP_VT220_DRIVER_NAME          "sclp_vt220"
+#define SCLP_VT220_DEVICE_NAME          "ttysclp"
+#define SCLP_VT220_CONSOLE_NAME         "ttyS"
+#define SCLP_VT220_CONSOLE_INDEX        1       /* console=ttyS1 */
+#define SCLP_VT220_BUF_SIZE             80
+
+/* Representation of a single write request */
+struct sclp_vt220_request {
+        struct list_head list;
+        struct sclp_req sclp_req;
+        int retry_count;
+};
+
+/* VT220 SCCB */
+struct sclp_vt220_sccb {
+        struct sccb_header header;
+        struct evbuf_header evbuf;
+};
+
+#define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \
+                                         sizeof(struct sclp_vt220_request) - \
+                                         sizeof(struct sclp_vt220_sccb))
+
+/* Structures and data needed to register tty driver */
+static struct tty_driver *sclp_vt220_driver;
+
+/* The tty_struct that the kernel associated with us */
+static struct tty_struct *sclp_vt220_tty;
+
+/* Lock to protect internal data from concurrent access */
+static spinlock_t sclp_vt220_lock;
+
+/* List of empty pages to be used as write request buffers */
+static struct list_head sclp_vt220_empty;
+
+/* List of pending requests */
+static struct list_head sclp_vt220_outqueue;
+
+/* Number of requests in outqueue */
+static int sclp_vt220_outqueue_count;
+
+/* Wait queue used to delay write requests while we've run out of buffers */
+static wait_queue_head_t sclp_vt220_waitq;
+
+/* Timer used for delaying write requests to merge subsequent messages into
+ * a single buffer */
+static struct timer_list sclp_vt220_timer;
+
+/* Pointer to current request buffer which has been partially filled but not
+ * yet sent */
+static struct sclp_vt220_request *sclp_vt220_current_request;
+
+/* Number of characters in current request buffer */
+static int sclp_vt220_buffered_chars;
+
+/* Flag indicating whether this driver has already been initialized */
+static int sclp_vt220_initialized = 0;
+
+/* Flag indicating that sclp_vt220_current_request should really
+ * have been already queued but wasn't because the SCLP was processing
+ * another buffer */
+static int sclp_vt220_flush_later;
+
+static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf);
+static int __sclp_vt220_emit(struct sclp_vt220_request *request);
+static void sclp_vt220_emit_current(void);
+
+/* Registration structure for our interest in SCLP event buffers */
+static struct sclp_register sclp_vt220_register = {
+        .send_mask              = EvTyp_VT220Msg_Mask,
+        .receive_mask           = EvTyp_VT220Msg_Mask,
+        .state_change_fn        = NULL,
+        .receiver_fn            = sclp_vt220_receiver_fn
+};
+
+
+/*
+ * Put provided request buffer back into queue and check emit pending
+ * buffers if necessary.
+ */
+static void
+sclp_vt220_process_queue(struct sclp_vt220_request *request)
+{
+        unsigned long flags;
+        void *page;
+
+        do {
+                /* Put buffer back to list of empty buffers */
+                page = request->sclp_req.sccb;
+                spin_lock_irqsave(&sclp_vt220_lock, flags);
+                /* Move request from outqueue to empty queue */
+                list_del(&request->list);
+                sclp_vt220_outqueue_count--;
+                list_add_tail((struct list_head *) page, &sclp_vt220_empty);
+                /* Check if there is a pending buffer on the out queue. */
+                request = NULL;
+                if (!list_empty(&sclp_vt220_outqueue))
+                        request = list_entry(sclp_vt220_outqueue.next,
+                                             struct sclp_vt220_request, list);
+                spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+        } while (request && __sclp_vt220_emit(request));
+        if (request == NULL && sclp_vt220_flush_later)
+                sclp_vt220_emit_current();
+        wake_up(&sclp_vt220_waitq);
+        /* Check if the tty needs a wake up call */
+        if (sclp_vt220_tty != NULL) {
+                tty_wakeup(sclp_vt220_tty);
+        }
+}
+
+#define SCLP_BUFFER_MAX_RETRY           1
+
+/*
+ * Callback through which the result of a write request is reported by the
+ * SCLP.
+ */
+static void
+sclp_vt220_callback(struct sclp_req *request, void *data)
+{
+        struct sclp_vt220_request *vt220_request;
+        struct sclp_vt220_sccb *sccb;
+
+        vt220_request = (struct sclp_vt220_request *) data;
+        if (request->status == SCLP_REQ_FAILED) {
+                sclp_vt220_process_queue(vt220_request);
+                return;
+        }
+        sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb;
+
+        /* Check SCLP response code and choose suitable action  */
+        switch (sccb->header.response_code) {
+        case 0x0020 :
+                break;
+
+        case 0x05f0: /* Target resource in improper state */
+                break;
+
+        case 0x0340: /* Contained SCLP equipment check */
+                if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY)
+                        break;
+                /* Remove processed buffers and requeue rest */
+                if (sclp_remove_processed((struct sccb_header *) sccb) > 0) {
+                        /* Not all buffers were processed */
+                        sccb->header.response_code = 0x0000;
+                        vt220_request->sclp_req.status = SCLP_REQ_FILLED;
+                        if (sclp_add_request(request) == 0)
+                                return;
+                }
+                break;
+
+        case 0x0040: /* SCLP equipment check */
+                if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY)
+                        break;
+                sccb->header.response_code = 0x0000;
+                vt220_request->sclp_req.status = SCLP_REQ_FILLED;
+                if (sclp_add_request(request) == 0)
+                        return;
+                break;
+
+        default:
+                break;
+        }
+        sclp_vt220_process_queue(vt220_request);
+}
+
+/*
+ * Emit vt220 request buffer to SCLP. Return zero on success, non-zero
+ * otherwise.
+ */
+static int
+__sclp_vt220_emit(struct sclp_vt220_request *request)
+{
+        if (!(sclp_vt220_register.sclp_send_mask & EvTyp_VT220Msg_Mask)) {
+                request->sclp_req.status = SCLP_REQ_FAILED;
+                return -EIO;
+        }
+        request->sclp_req.command = SCLP_CMDW_WRITEDATA;
+        request->sclp_req.status = SCLP_REQ_FILLED;
+        request->sclp_req.callback = sclp_vt220_callback;
+        request->sclp_req.callback_data = (void *) request;
+
+        return sclp_add_request(&request->sclp_req);
+}
+
+/*
+ * Queue and emit given request.
+ */
+static void
+sclp_vt220_emit(struct sclp_vt220_request *request)
+{
+        unsigned long flags;
+        int count;
+
+        spin_lock_irqsave(&sclp_vt220_lock, flags);
+        list_add_tail(&request->list, &sclp_vt220_outqueue);
+        count = sclp_vt220_outqueue_count++;
+        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+        /* Emit only the first buffer immediately - callback takes care of
+         * the rest */
+        if (count == 0 && __sclp_vt220_emit(request))
+                sclp_vt220_process_queue(request);
+}
+
+/*
+ * Queue and emit current request. Return zero on success, non-zero otherwise.
+ */
+static void
+sclp_vt220_emit_current(void)
+{
+        unsigned long flags;
+        struct sclp_vt220_request *request;
+        struct sclp_vt220_sccb *sccb;
+
+        spin_lock_irqsave(&sclp_vt220_lock, flags);
+        request = NULL;
+        if (sclp_vt220_current_request != NULL) {
+                sccb = (struct sclp_vt220_sccb *) 
+                                sclp_vt220_current_request->sclp_req.sccb;
+                /* Only emit buffers with content */
+                if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) {
+                        request = sclp_vt220_current_request;
+                        sclp_vt220_current_request = NULL;
+                        if (timer_pending(&sclp_vt220_timer))
+                                del_timer(&sclp_vt220_timer);
+                }
+                sclp_vt220_flush_later = 0;
+        }
+        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+        if (request != NULL)
+                sclp_vt220_emit(request);
+}
+
+#define SCLP_NORMAL_WRITE       0x00
+
+/*
+ * Helper function to initialize a page with the sclp request structure.
+ */
+static struct sclp_vt220_request *
+sclp_vt220_initialize_page(void *page)
+{
+        struct sclp_vt220_request *request;
+        struct sclp_vt220_sccb *sccb;
+
+        /* Place request structure at end of page */
+        request = ((struct sclp_vt220_request *)
+                        ((addr_t) page + PAGE_SIZE)) - 1;
+        request->retry_count = 0;
+        request->sclp_req.sccb = page;
+        /* SCCB goes at start of page */
+        sccb = (struct sclp_vt220_sccb *) page;
+        memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb));
+        sccb->header.length = sizeof(struct sclp_vt220_sccb);
+        sccb->header.function_code = SCLP_NORMAL_WRITE;
+        sccb->header.response_code = 0x0000;
+        sccb->evbuf.type = EvTyp_VT220Msg;
+        sccb->evbuf.length = sizeof(struct evbuf_header);
+
+        return request;
+}
+
+static inline unsigned int
+sclp_vt220_space_left(struct sclp_vt220_request *request)
+{
+        struct sclp_vt220_sccb *sccb;
+        sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
+        return PAGE_SIZE - sizeof(struct sclp_vt220_request) -
+               sccb->header.length;
+}
+
+static inline unsigned int
+sclp_vt220_chars_stored(struct sclp_vt220_request *request)
+{
+        struct sclp_vt220_sccb *sccb;
+        sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
+        return sccb->evbuf.length - sizeof(struct evbuf_header);
+}
+
+/*
+ * Add msg to buffer associated with request. Return the number of characters
+ * added.
+ */
+static int
+sclp_vt220_add_msg(struct sclp_vt220_request *request,
+                   const unsigned char *msg, int count, int convertlf)
+{
+        struct sclp_vt220_sccb *sccb;
+        void *buffer;
+        unsigned char c;
+        int from;
+        int to;
+
+        if (count > sclp_vt220_space_left(request))
+                count = sclp_vt220_space_left(request);
+        if (count <= 0)
+                return 0;
+
+        sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
+        buffer = (void *) ((addr_t) sccb + sccb->header.length);
+
+        if (convertlf) {
+                /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/
+                for (from=0, to=0;
+                     (from < count) && (to < sclp_vt220_space_left(request));
+                     from++) {
+                        /* Retrieve character */
+                        c = msg[from];
+                        /* Perform conversion */
+                        if (c == 0x0a) {
+                                if (to + 1 < sclp_vt220_space_left(request)) {
+                                        ((unsigned char *) buffer)[to++] = c;
+                                        ((unsigned char *) buffer)[to++] = 0x0d;
+                                } else
+                                        break;
+
+                        } else
+                                ((unsigned char *) buffer)[to++] = c;
+                }
+                sccb->header.length += to;
+                sccb->evbuf.length += to;
+                return from;
+        } else {
+                memcpy(buffer, (const void *) msg, count);
+                sccb->header.length += count;
+                sccb->evbuf.length += count;
+                return count;
+        }
+}
+
+/*
+ * Emit buffer after having waited long enough for more data to arrive.
+ */
+static void
+sclp_vt220_timeout(unsigned long data)
+{
+        sclp_vt220_emit_current();
+}
+
+#define BUFFER_MAX_DELAY        HZ/2
+
+/* 
+ * Internal implementation of the write function. Write COUNT bytes of data
+ * from memory at BUF
+ * to the SCLP interface. In case that the data does not fit into the current
+ * write buffer, emit the current one and allocate a new one. If there are no
+ * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE
+ * is non-zero, the buffer will be scheduled for emitting after a timeout -
+ * otherwise the user has to explicitly call the flush function.
+ * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message
+ * buffer should be converted to 0x0a 0x0d. After completion, return the number
+ * of bytes written.
+ */
+static int
+__sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
+                   int convertlf)
+{
+        unsigned long flags;
+        void *page;
+        int written;
+        int overall_written;
+
+        if (count <= 0)
+                return 0;
+        overall_written = 0;
+        spin_lock_irqsave(&sclp_vt220_lock, flags);
+        do {
+                /* Create a sclp output buffer if none exists yet */
+                if (sclp_vt220_current_request == NULL) {
+                        while (list_empty(&sclp_vt220_empty)) {
+                                spin_unlock_irqrestore(&sclp_vt220_lock,
+                                                       flags);
+                                if (in_interrupt())
+                                        sclp_sync_wait();
+                                else
+                                        wait_event(sclp_vt220_waitq,
+                                                !list_empty(&sclp_vt220_empty));
+                                spin_lock_irqsave(&sclp_vt220_lock, flags);
+                        }
+                        page = (void *) sclp_vt220_empty.next;
+                        list_del((struct list_head *) page);
+                        sclp_vt220_current_request =
+                                sclp_vt220_initialize_page(page);
+                }
+                /* Try to write the string to the current request buffer */
+                written = sclp_vt220_add_msg(sclp_vt220_current_request,
+                                             buf, count, convertlf);
+                overall_written += written;
+                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.
+                 */
+                spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+                sclp_vt220_emit_current();
+                spin_lock_irqsave(&sclp_vt220_lock, flags);
+                buf += written;
+                count -= written;
+        } while (count > 0);
+        /* Setup timer to output current console buffer after some time */
+        if (sclp_vt220_current_request != NULL &&
+            !timer_pending(&sclp_vt220_timer) && do_schedule) {
+                sclp_vt220_timer.function = sclp_vt220_timeout;
+                sclp_vt220_timer.data = 0UL;
+                sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY;
+                add_timer(&sclp_vt220_timer);
+        }
+        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+        return overall_written;
+}
+
+/*
+ * 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_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+        return __sclp_vt220_write(buf, count, 1, 0);
+}
+
+#define SCLP_VT220_SESSION_ENDED        0x01
+#define SCLP_VT220_SESSION_STARTED      0x80
+#define SCLP_VT220_SESSION_DATA         0x00
+
+/*
+ * Called by the SCLP to report incoming event buffers.
+ */
+static void
+sclp_vt220_receiver_fn(struct evbuf_header *evbuf)
+{
+        char *buffer;
+        unsigned int count;
+
+        /* Ignore input if device is not open */
+        if (sclp_vt220_tty == NULL)
+                return;
+
+        buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header));
+        count = evbuf->length - sizeof(struct evbuf_header);
+
+        switch (*buffer) {
+        case SCLP_VT220_SESSION_ENDED:
+        case SCLP_VT220_SESSION_STARTED:
+                break;
+        case SCLP_VT220_SESSION_DATA:
+                /* Send input to line discipline */
+                buffer++;
+                count--;
+                /* Prevent buffer overrun by discarding input. Note that
+                 * because buffer_push works asynchronously, we cannot wait
+                 * for the buffer to be emptied. */
+                if (count + sclp_vt220_tty->flip.count > TTY_FLIPBUF_SIZE)
+                        count = TTY_FLIPBUF_SIZE - sclp_vt220_tty->flip.count;
+                memcpy(sclp_vt220_tty->flip.char_buf_ptr, buffer, count);
+                memset(sclp_vt220_tty->flip.flag_buf_ptr, TTY_NORMAL, count);
+                sclp_vt220_tty->flip.char_buf_ptr += count;
+                sclp_vt220_tty->flip.flag_buf_ptr += count;
+                sclp_vt220_tty->flip.count += count;
+                tty_flip_buffer_push(sclp_vt220_tty);
+                break;
+        }
+}
+
+/*
+ * This routine is called when a particular tty device is opened.
+ */
+static int
+sclp_vt220_open(struct tty_struct *tty, struct file *filp)
+{
+        if (tty->count == 1) {
+                sclp_vt220_tty = tty;
+                tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL);
+                if (tty->driver_data == NULL)
+                        return -ENOMEM;
+                tty->low_latency = 0;
+        }
+        return 0;
+}
+
+/*
+ * This routine is called when a particular tty device is closed.
+ */
+static void
+sclp_vt220_close(struct tty_struct *tty, struct file *filp)
+{
+        if (tty->count == 1) {
+                sclp_vt220_tty = NULL;
+                kfree(tty->driver_data);
+                tty->driver_data = NULL;
+        }
+}
+
+/*
+ * 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.
+ *
+ * NOTE: include/linux/tty_driver.h specifies that a character should be
+ * ignored if there is no room in the queue. This driver implements a different
+ * semantic in that it will block when there is no more room left.
+ */
+static void
+sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
+{
+        __sclp_vt220_write(&ch, 1, 0, 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_vt220_flush_chars(struct tty_struct *tty)
+{
+        if (sclp_vt220_outqueue_count == 0)
+                sclp_vt220_emit_current();
+        else
+                sclp_vt220_flush_later = 1;
+}
+
+/*
+ * 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.
+ */
+static int
+sclp_vt220_write_room(struct tty_struct *tty)
+{
+        unsigned long flags;
+        struct list_head *l;
+        int count;
+
+        spin_lock_irqsave(&sclp_vt220_lock, flags);
+        count = 0;
+        if (sclp_vt220_current_request != NULL)
+                count = sclp_vt220_space_left(sclp_vt220_current_request);
+        list_for_each(l, &sclp_vt220_empty)
+                count += SCLP_VT220_MAX_CHARS_PER_BUFFER;
+        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+        return count;
+}
+
+/*
+ * Return number of buffered chars.
+ */
+static int
+sclp_vt220_chars_in_buffer(struct tty_struct *tty)
+{
+        unsigned long flags;
+        struct list_head *l;
+        struct sclp_vt220_request *r;
+        int count;
+
+        spin_lock_irqsave(&sclp_vt220_lock, flags);
+        count = 0;
+        if (sclp_vt220_current_request != NULL)
+                count = sclp_vt220_chars_stored(sclp_vt220_current_request);
+        list_for_each(l, &sclp_vt220_outqueue) {
+                r = list_entry(l, struct sclp_vt220_request, list);
+                count += sclp_vt220_chars_stored(r);
+        }
+        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+        return count;
+}
+
+static void
+__sclp_vt220_flush_buffer(void)
+{
+        unsigned long flags;
+
+        sclp_vt220_emit_current();
+        spin_lock_irqsave(&sclp_vt220_lock, flags);
+        if (timer_pending(&sclp_vt220_timer))
+                del_timer(&sclp_vt220_timer);
+        while (sclp_vt220_outqueue_count > 0) {
+                spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+                sclp_sync_wait();
+                spin_lock_irqsave(&sclp_vt220_lock, flags);
+        }
+        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+}
+
+/*
+ * Pass on all buffers to the hardware. Return only when there are no more
+ * buffers pending.
+ */
+static void
+sclp_vt220_flush_buffer(struct tty_struct *tty)
+{
+        sclp_vt220_emit_current();
+}
+
+/*
+ * Initialize all relevant components and register driver with system.
+ */
+static int
+__sclp_vt220_init(int early)
+{
+        void *page;
+        int i;
+
+        if (sclp_vt220_initialized)
+                return 0;
+        sclp_vt220_initialized = 1;
+        spin_lock_init(&sclp_vt220_lock);
+        INIT_LIST_HEAD(&sclp_vt220_empty);
+        INIT_LIST_HEAD(&sclp_vt220_outqueue);
+        init_waitqueue_head(&sclp_vt220_waitq);
+        init_timer(&sclp_vt220_timer);
+        sclp_vt220_current_request = NULL;
+        sclp_vt220_buffered_chars = 0;
+        sclp_vt220_outqueue_count = 0;
+        sclp_vt220_tty = NULL;
+        sclp_vt220_flush_later = 0;
+
+        /* Allocate pages for output buffering */
+        for (i = 0; i < (early ? MAX_CONSOLE_PAGES : MAX_KMEM_PAGES); i++) {
+                if (early)
+                        page = alloc_bootmem_low_pages(PAGE_SIZE);
+                else
+                        page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+                if (!page)
+                        return -ENOMEM;
+                list_add_tail((struct list_head *) page, &sclp_vt220_empty);
+        }
+        return 0;
+}
+
+static struct tty_operations sclp_vt220_ops = {
+        .open = sclp_vt220_open,
+        .close = sclp_vt220_close,
+        .write = sclp_vt220_write,
+        .put_char = sclp_vt220_put_char,
+        .flush_chars = sclp_vt220_flush_chars,
+        .write_room = sclp_vt220_write_room,
+        .chars_in_buffer = sclp_vt220_chars_in_buffer,
+        .flush_buffer = sclp_vt220_flush_buffer
+};
+
+/*
+ * Register driver with SCLP and Linux and initialize internal tty structures.
+ */
+int __init
+sclp_vt220_tty_init(void)
+{
+        struct tty_driver *driver;
+        int rc;
+
+        /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve
+         * symmetry between VM and LPAR systems regarding ttyS1. */
+        driver = alloc_tty_driver(1);
+        if (!driver)
+                return -ENOMEM;
+        rc = __sclp_vt220_init(0);
+        if (rc) {
+                put_tty_driver(driver);
+                return rc;
+        }
+        rc = sclp_register(&sclp_vt220_register);
+        if (rc) {
+                printk(KERN_ERR SCLP_VT220_PRINT_HEADER
+                       "could not register tty - "
+                       "sclp_register returned %d\n", rc);
+                put_tty_driver(driver);
+                return rc;
+        }
+
+        driver->owner = THIS_MODULE;
+        driver->driver_name = SCLP_VT220_DRIVER_NAME;
+        driver->name = SCLP_VT220_DEVICE_NAME;
+        driver->major = SCLP_VT220_MAJOR;
+        driver->minor_start = SCLP_VT220_MINOR;
+        driver->type = TTY_DRIVER_TYPE_SYSTEM;
+        driver->subtype = SYSTEM_TYPE_TTY;
+        driver->init_termios = tty_std_termios;
+        driver->flags = TTY_DRIVER_REAL_RAW;
+        tty_set_operations(driver, &sclp_vt220_ops);
+
+        rc = tty_register_driver(driver);
+        if (rc) {
+                printk(KERN_ERR SCLP_VT220_PRINT_HEADER
+                       "could not register tty - "
+                       "tty_register_driver returned %d\n", rc);
+                put_tty_driver(driver);
+                return rc;
+        }
+        sclp_vt220_driver = driver;
+        return 0;
+}
+
+module_init(sclp_vt220_tty_init);
+
+#ifdef CONFIG_SCLP_VT220_CONSOLE
+
+static void
+sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count)
+{
+        __sclp_vt220_write((const unsigned char *) buf, count, 1, 1);
+}
+
+static struct tty_driver *
+sclp_vt220_con_device(struct console *c, int *index)
+{
+        *index = 0;
+        return sclp_vt220_driver;
+}
+
+/*
+ * This routine is called from panic when the kernel is going to give up.
+ * We have to make sure that all buffers will be flushed to the SCLP.
+ * Note that this function may be called from within an interrupt context.
+ */
+static void
+sclp_vt220_con_unblank(void)
+{
+        __sclp_vt220_flush_buffer();
+}
+
+/* Structure needed to register with printk */
+static struct console sclp_vt220_console =
+{
+        .name = SCLP_VT220_CONSOLE_NAME,
+        .write = sclp_vt220_con_write,
+        .device = sclp_vt220_con_device,
+        .unblank = sclp_vt220_con_unblank,
+        .flags = CON_PRINTBUFFER,
+        .index = SCLP_VT220_CONSOLE_INDEX
+};
+
+static int __init
+sclp_vt220_con_init(void)
+{
+        int rc;
+
+        if (!CONSOLE_IS_SCLP)
+                return 0;
+        rc = __sclp_vt220_init(1);
+        if (rc)
+                return rc;
+        /* Attach linux console */
+        register_console(&sclp_vt220_console);
+        return 0;
+}
+
+console_initcall(sclp_vt220_con_init);
+#endif /* CONFIG_SCLP_VT220_CONSOLE */
+