--- /dev/null
+/*
+ * SCLP line mode terminal driver.
+ *
+ * S390 version
+ * Copyright IBM Corp. 1999
+ * Author(s): Martin Peschke <mpeschke@de.ibm.com>
+ * Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/gfp.h>
+#include <asm/uaccess.h>
+
+#include "ctrlchar.h"
+#include "sclp.h"
+#include "sclp_rw.h"
+#include "sclp_tty.h"
+
+/*
+ * 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;
+
+static struct tty_port sclp_port;
+static unsigned char sclp_tty_chars[SCLP_TTY_BUF_SIZE];
+static unsigned short int sclp_tty_chars_count;
+
+struct tty_driver *sclp_tty_driver;
+
+static int sclp_tty_tolower;
+static int sclp_tty_columns = 80;
+
+#define SPACES_PER_TAB 8
+#define CASE_DELIMITER 0x6c /* to separate 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)
+{
+ tty_port_tty_set(&sclp_port, tty);
+ tty->driver_data = NULL;
+ sclp_port.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;
+ tty_port_tty_set(&sclp_port, NULL);
+}
+
+/*
+ * 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));
+
+ tty_port_tty_wakeup(&sclp_port);
+}
+
+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 int sclp_tty_write_string(const unsigned char *str, int count, int may_fail)
+{
+ unsigned long flags;
+ void *page;
+ int written;
+ int overall_written;
+ struct sclp_buffer *buf;
+
+ if (count <= 0)
+ return 0;
+ overall_written = 0;
+ 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 (may_fail)
+ goto out;
+ else
+ sclp_sync_wait();
+ 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_tty_columns,
+ SPACES_PER_TAB);
+ }
+ /* try to write the string to the current output buffer */
+ written = sclp_write(sclp_ttybuf, str, count);
+ 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.
+ */
+ 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_ttybuf && sclp_chars_in_buffer(sclp_ttybuf) &&
+ !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);
+ }
+ spin_unlock_irqrestore(&sclp_tty_lock, flags);
+out:
+ 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_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, 0);
+ sclp_tty_chars_count = 0;
+ }
+ return sclp_tty_write_string(buf, count, 1);
+}
+
+/*
+ * 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 int
+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, 0);
+ sclp_tty_chars_count = 0;
+ }
+ return 1;
+}
+
+/*
+ * 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, 0);
+ 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, 0);
+ sclp_tty_chars_count = 0;
+ }
+}
+
+/*
+ * push input to tty
+ */
+static void
+sclp_tty_input(unsigned char* buf, unsigned int count)
+{
+ struct tty_struct *tty = tty_port_tty_get(&sclp_port);
+ unsigned int cchar;
+
+ /*
+ * If this tty driver is currently closed
+ * then throw the received input away.
+ */
+ if (tty == NULL)
+ return;
+ cchar = ctrlchar_handle(buf, count, tty);
+ switch (cchar & CTRLCHAR_MASK) {
+ case CTRLCHAR_SYSRQ:
+ break;
+ case CTRLCHAR_CTRL:
+ tty_insert_flip_char(&sclp_port, cchar, TTY_NORMAL);
+ tty_flip_buffer_push(&sclp_port);
+ break;
+ case CTRLCHAR_NONE:
+ /* send (normal) input to line discipline */
+ if (count < 2 ||
+ (strncmp((const char *) buf + count - 2, "^n", 2) &&
+ strncmp((const char *) buf + count - 2, "\252n", 2))) {
+ /* add the auto \n */
+ tty_insert_flip_string(&sclp_port, buf, count);
+ tty_insert_flip_char(&sclp_port, '\n', TTY_NORMAL);
+ } else
+ tty_insert_flip_string(&sclp_port, buf, count - 2);
+ tty_flip_buffer_push(&sclp_port);
+ break;
+ }
+ tty_kref_put(tty);
+}
+
+/*
+ * 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 *ip, *op;
+ int toggle;
+
+ /* initially changing case is off */
+ toggle = 0;
+ ip = op = buf;
+ while (count-- > 0) {
+ /* compare with special character */
+ if (*ip == CASE_DELIMITER) {
+ /* followed by another special character? */
+ if (count && ip[1] == CASE_DELIMITER) {
+ /*
+ * ... 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 (sclp_tty_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(struct gds_subvector *sv)
+{
+ unsigned char *str;
+ int count;
+
+ str = (unsigned char *) (sv + 1);
+ count = sv->length - sizeof(*sv);
+ if (sclp_tty_tolower)
+ EBC_TOLOWER(str, count);
+ count = sclp_switch_cases(str, count);
+ /* convert EBCDIC to ASCII (modify original input in SCCB) */
+ sclp_ebcasc_str(str, count);
+
+ /* transfer input to high level driver */
+ sclp_tty_input(str, count);
+}
+
+static inline void sclp_eval_selfdeftextmsg(struct gds_subvector *sv)
+{
+ void *end;
+
+ end = (void *) sv + sv->length;
+ for (sv = sv + 1; (void *) sv < end; sv = (void *) sv + sv->length)
+ if (sv->key == 0x30)
+ sclp_get_input(sv);
+}
+
+static inline void sclp_eval_textcmd(struct gds_vector *v)
+{
+ struct gds_subvector *sv;
+ void *end;
+
+ end = (void *) v + v->length;
+ for (sv = (struct gds_subvector *) (v + 1);
+ (void *) sv < end; sv = (void *) sv + sv->length)
+ if (sv->key == GDS_KEY_SELFDEFTEXTMSG)
+ sclp_eval_selfdeftextmsg(sv);
+
+}
+
+static inline void sclp_eval_cpmsu(struct gds_vector *v)
+{
+ void *end;
+
+ end = (void *) v + v->length;
+ for (v = v + 1; (void *) v < end; v = (void *) v + v->length)
+ if (v->gds_id == GDS_ID_TEXTCMD)
+ sclp_eval_textcmd(v);
+}
+
+
+static inline void sclp_eval_mdsmu(struct gds_vector *v)
+{
+ v = sclp_find_gds_vector(v + 1, (void *) v + v->length, GDS_ID_CPMSU);
+ if (v)
+ sclp_eval_cpmsu(v);
+}
+
+static void sclp_tty_receiver(struct evbuf_header *evbuf)
+{
+ struct gds_vector *v;
+
+ v = sclp_find_gds_vector(evbuf + 1, (void *) evbuf + evbuf->length,
+ GDS_ID_MDSMU);
+ if (v)
+ sclp_eval_mdsmu(v);
+}
+
+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 const 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,
+};
+
+static 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) {
+ 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_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_tty_columns = 76;
+ /* case input lines to lowercase */
+ sclp_tty_tolower = 1;
+ }
+ sclp_tty_chars_count = 0;
+
+ rc = sclp_register(&sclp_input_event);
+ if (rc) {
+ put_tty_driver(driver);
+ return rc;
+ }
+
+ tty_port_init(&sclp_port);
+
+ 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;
+ driver->init_termios.c_lflag = ISIG | ECHO;
+ driver->flags = TTY_DRIVER_REAL_RAW;
+ tty_set_operations(driver, &sclp_ops);
+ tty_port_link_device(&sclp_port, driver, 0);
+ rc = tty_register_driver(driver);
+ if (rc) {
+ put_tty_driver(driver);
+ tty_port_destroy(&sclp_port);
+ return rc;
+ }
+ sclp_tty_driver = driver;
+ return 0;
+}
+module_init(sclp_tty_init);
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