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commit8f50af49f5
("s390/console: Make preferred console handling more consistent") created a separate console state for the ascii console. This has the side effect that we register no tty for the line mode interface as soon as there an ascii interface as default console. Under KVM this results in no getty program on the line mode tty if the guest has both types of interfaces. As we can have multiple ttys at the same time we do not want to disable the tty on sclp_line0 under KVM. So instead of checking for the console mode, we now check for the presence of the sclp line mode interface. As z/VM multiplexes the line mode interface on the 32xx screen we continue to disable the line mode tty for the z/VM case. CC: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Fixes:8f50af49f5
("s390/console: Make preferred console handling more consistent") Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
575 lines
15 KiB
C
575 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* SCLP line mode terminal driver.
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*
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* S390 version
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* Copyright IBM Corp. 1999
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* Author(s): Martin Peschke <mpeschke@de.ibm.com>
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* Martin Schwidefsky <schwidefsky@de.ibm.com>
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*/
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#include <linux/kmod.h>
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#include <linux/tty.h>
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#include <linux/tty_driver.h>
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#include <linux/tty_flip.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/gfp.h>
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#include <linux/uaccess.h>
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#include "ctrlchar.h"
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#include "sclp.h"
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#include "sclp_rw.h"
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#include "sclp_tty.h"
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/*
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* size of a buffer that collects single characters coming in
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* via sclp_tty_put_char()
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*/
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#define SCLP_TTY_BUF_SIZE 512
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/*
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* There is exactly one SCLP terminal, so we can keep things simple
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* and allocate all variables statically.
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*/
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/* Lock to guard over changes to global variables. */
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static spinlock_t sclp_tty_lock;
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/* List of free pages that can be used for console output buffering. */
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static struct list_head sclp_tty_pages;
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/* List of full struct sclp_buffer structures ready for output. */
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static struct list_head sclp_tty_outqueue;
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/* Counter how many buffers are emitted. */
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static int sclp_tty_buffer_count;
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/* Pointer to current console buffer. */
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static struct sclp_buffer *sclp_ttybuf;
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/* Timer for delayed output of console messages. */
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static struct timer_list sclp_tty_timer;
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static struct tty_port sclp_port;
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static unsigned char sclp_tty_chars[SCLP_TTY_BUF_SIZE];
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static unsigned short int sclp_tty_chars_count;
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struct tty_driver *sclp_tty_driver;
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static int sclp_tty_tolower;
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static int sclp_tty_columns = 80;
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#define SPACES_PER_TAB 8
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#define CASE_DELIMITER 0x6c /* to separate upper and lower case (% in EBCDIC) */
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/* This routine is called whenever we try to open a SCLP terminal. */
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static int
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sclp_tty_open(struct tty_struct *tty, struct file *filp)
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{
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tty_port_tty_set(&sclp_port, tty);
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tty->driver_data = NULL;
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sclp_port.low_latency = 0;
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return 0;
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}
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/* This routine is called when the SCLP terminal is closed. */
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static void
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sclp_tty_close(struct tty_struct *tty, struct file *filp)
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{
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if (tty->count > 1)
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return;
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tty_port_tty_set(&sclp_port, NULL);
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}
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/*
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* This routine returns the numbers of characters the tty driver
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* will accept for queuing to be written. This number is subject
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* to change as output buffers get emptied, or if the output flow
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* control is acted. This is not an exact number because not every
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* character needs the same space in the sccb. The worst case is
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* a string of newlines. Every newline creates a new message which
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* needs 82 bytes.
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*/
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static int
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sclp_tty_write_room (struct tty_struct *tty)
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{
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unsigned long flags;
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struct list_head *l;
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int count;
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spin_lock_irqsave(&sclp_tty_lock, flags);
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count = 0;
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if (sclp_ttybuf != NULL)
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count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct msg_buf);
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list_for_each(l, &sclp_tty_pages)
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count += NR_EMPTY_MSG_PER_SCCB;
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spin_unlock_irqrestore(&sclp_tty_lock, flags);
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return count;
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}
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static void
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sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
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{
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unsigned long flags;
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void *page;
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do {
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page = sclp_unmake_buffer(buffer);
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spin_lock_irqsave(&sclp_tty_lock, flags);
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/* Remove buffer from outqueue */
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list_del(&buffer->list);
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sclp_tty_buffer_count--;
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list_add_tail((struct list_head *) page, &sclp_tty_pages);
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/* Check if there is a pending buffer on the out queue. */
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buffer = NULL;
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if (!list_empty(&sclp_tty_outqueue))
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buffer = list_entry(sclp_tty_outqueue.next,
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struct sclp_buffer, list);
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spin_unlock_irqrestore(&sclp_tty_lock, flags);
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} while (buffer && sclp_emit_buffer(buffer, sclp_ttybuf_callback));
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tty_port_tty_wakeup(&sclp_port);
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}
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static inline void
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__sclp_ttybuf_emit(struct sclp_buffer *buffer)
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{
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unsigned long flags;
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int count;
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int rc;
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spin_lock_irqsave(&sclp_tty_lock, flags);
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list_add_tail(&buffer->list, &sclp_tty_outqueue);
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count = sclp_tty_buffer_count++;
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spin_unlock_irqrestore(&sclp_tty_lock, flags);
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if (count)
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return;
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rc = sclp_emit_buffer(buffer, sclp_ttybuf_callback);
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if (rc)
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sclp_ttybuf_callback(buffer, rc);
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}
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/*
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* When this routine is called from the timer then we flush the
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* temporary write buffer.
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*/
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static void
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sclp_tty_timeout(struct timer_list *unused)
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{
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unsigned long flags;
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struct sclp_buffer *buf;
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spin_lock_irqsave(&sclp_tty_lock, flags);
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buf = sclp_ttybuf;
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sclp_ttybuf = NULL;
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spin_unlock_irqrestore(&sclp_tty_lock, flags);
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if (buf != NULL) {
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__sclp_ttybuf_emit(buf);
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}
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}
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/*
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* Write a string to the sclp tty.
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*/
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static int sclp_tty_write_string(const unsigned char *str, int count, int may_fail)
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{
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unsigned long flags;
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void *page;
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int written;
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int overall_written;
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struct sclp_buffer *buf;
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if (count <= 0)
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return 0;
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overall_written = 0;
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spin_lock_irqsave(&sclp_tty_lock, flags);
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do {
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/* Create a sclp output buffer if none exists yet */
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if (sclp_ttybuf == NULL) {
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while (list_empty(&sclp_tty_pages)) {
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spin_unlock_irqrestore(&sclp_tty_lock, flags);
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if (may_fail)
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goto out;
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else
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sclp_sync_wait();
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spin_lock_irqsave(&sclp_tty_lock, flags);
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}
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page = sclp_tty_pages.next;
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list_del((struct list_head *) page);
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sclp_ttybuf = sclp_make_buffer(page, sclp_tty_columns,
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SPACES_PER_TAB);
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}
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/* try to write the string to the current output buffer */
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written = sclp_write(sclp_ttybuf, str, count);
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overall_written += written;
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if (written == count)
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break;
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/*
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* Not all characters could be written to the current
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* output buffer. Emit the buffer, create a new buffer
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* and then output the rest of the string.
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*/
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buf = sclp_ttybuf;
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sclp_ttybuf = NULL;
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spin_unlock_irqrestore(&sclp_tty_lock, flags);
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__sclp_ttybuf_emit(buf);
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spin_lock_irqsave(&sclp_tty_lock, flags);
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str += written;
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count -= written;
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} while (count > 0);
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/* Setup timer to output current console buffer after 1/10 second */
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if (sclp_ttybuf && sclp_chars_in_buffer(sclp_ttybuf) &&
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!timer_pending(&sclp_tty_timer)) {
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mod_timer(&sclp_tty_timer, jiffies + HZ / 10);
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}
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spin_unlock_irqrestore(&sclp_tty_lock, flags);
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out:
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return overall_written;
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}
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/*
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* This routine is called by the kernel to write a series of characters to the
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* tty device. The characters may come from user space or kernel space. This
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* routine will return the number of characters actually accepted for writing.
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*/
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static int
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sclp_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
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{
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if (sclp_tty_chars_count > 0) {
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sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
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sclp_tty_chars_count = 0;
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}
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return sclp_tty_write_string(buf, count, 1);
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}
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/*
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* This routine is called by the kernel to write a single character to the tty
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* device. If the kernel uses this routine, it must call the flush_chars()
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* routine (if defined) when it is done stuffing characters into the driver.
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*
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* Characters provided to sclp_tty_put_char() are buffered by the SCLP driver.
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* If the given character is a '\n' the contents of the SCLP write buffer
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* - including previous characters from sclp_tty_put_char() and strings from
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* sclp_write() without final '\n' - will be written.
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*/
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static int
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sclp_tty_put_char(struct tty_struct *tty, unsigned char ch)
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{
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sclp_tty_chars[sclp_tty_chars_count++] = ch;
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if (ch == '\n' || sclp_tty_chars_count >= SCLP_TTY_BUF_SIZE) {
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sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
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sclp_tty_chars_count = 0;
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}
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return 1;
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}
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/*
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* This routine is called by the kernel after it has written a series of
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* characters to the tty device using put_char().
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*/
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static void
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sclp_tty_flush_chars(struct tty_struct *tty)
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{
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if (sclp_tty_chars_count > 0) {
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sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
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sclp_tty_chars_count = 0;
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}
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}
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/*
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* This routine returns the number of characters in the write buffer of the
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* SCLP driver. The provided number includes all characters that are stored
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* in the SCCB (will be written next time the SCLP is not busy) as well as
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* characters in the write buffer (will not be written as long as there is a
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* final line feed missing).
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*/
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static int
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sclp_tty_chars_in_buffer(struct tty_struct *tty)
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{
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unsigned long flags;
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struct list_head *l;
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struct sclp_buffer *t;
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int count;
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spin_lock_irqsave(&sclp_tty_lock, flags);
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count = 0;
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if (sclp_ttybuf != NULL)
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count = sclp_chars_in_buffer(sclp_ttybuf);
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list_for_each(l, &sclp_tty_outqueue) {
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t = list_entry(l, struct sclp_buffer, list);
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count += sclp_chars_in_buffer(t);
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}
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spin_unlock_irqrestore(&sclp_tty_lock, flags);
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return count;
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}
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/*
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* removes all content from buffers of low level driver
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*/
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static void
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sclp_tty_flush_buffer(struct tty_struct *tty)
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{
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if (sclp_tty_chars_count > 0) {
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sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
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sclp_tty_chars_count = 0;
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}
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}
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/*
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* push input to tty
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*/
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static void
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sclp_tty_input(unsigned char* buf, unsigned int count)
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{
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struct tty_struct *tty = tty_port_tty_get(&sclp_port);
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unsigned int cchar;
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/*
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* If this tty driver is currently closed
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* then throw the received input away.
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*/
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if (tty == NULL)
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return;
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cchar = ctrlchar_handle(buf, count, tty);
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switch (cchar & CTRLCHAR_MASK) {
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case CTRLCHAR_SYSRQ:
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break;
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case CTRLCHAR_CTRL:
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tty_insert_flip_char(&sclp_port, cchar, TTY_NORMAL);
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tty_flip_buffer_push(&sclp_port);
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break;
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case CTRLCHAR_NONE:
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/* send (normal) input to line discipline */
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if (count < 2 ||
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(strncmp((const char *) buf + count - 2, "^n", 2) &&
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strncmp((const char *) buf + count - 2, "\252n", 2))) {
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/* add the auto \n */
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tty_insert_flip_string(&sclp_port, buf, count);
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tty_insert_flip_char(&sclp_port, '\n', TTY_NORMAL);
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} else
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tty_insert_flip_string(&sclp_port, buf, count - 2);
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tty_flip_buffer_push(&sclp_port);
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break;
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}
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tty_kref_put(tty);
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}
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/*
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* get a EBCDIC string in upper/lower case,
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* find out characters in lower/upper case separated by a special character,
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* modifiy original string,
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* returns length of resulting string
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*/
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static int sclp_switch_cases(unsigned char *buf, int count)
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{
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unsigned char *ip, *op;
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int toggle;
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/* initially changing case is off */
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toggle = 0;
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ip = op = buf;
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while (count-- > 0) {
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/* compare with special character */
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if (*ip == CASE_DELIMITER) {
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/* followed by another special character? */
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if (count && ip[1] == CASE_DELIMITER) {
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/*
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* ... then put a single copy of the special
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* character to the output string
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*/
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*op++ = *ip++;
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count--;
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} else
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/*
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* ... special character follower by a normal
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* character toggles the case change behaviour
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*/
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toggle = ~toggle;
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/* skip special character */
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ip++;
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} else
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/* not the special character */
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if (toggle)
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/* but case switching is on */
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if (sclp_tty_tolower)
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/* switch to uppercase */
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*op++ = _ebc_toupper[(int) *ip++];
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else
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/* switch to lowercase */
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*op++ = _ebc_tolower[(int) *ip++];
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else
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/* no case switching, copy the character */
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*op++ = *ip++;
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}
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/* return length of reformatted string. */
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return op - buf;
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}
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static void sclp_get_input(struct gds_subvector *sv)
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{
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unsigned char *str;
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int count;
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str = (unsigned char *) (sv + 1);
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count = sv->length - sizeof(*sv);
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if (sclp_tty_tolower)
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EBC_TOLOWER(str, count);
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count = sclp_switch_cases(str, count);
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/* convert EBCDIC to ASCII (modify original input in SCCB) */
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sclp_ebcasc_str(str, count);
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/* transfer input to high level driver */
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sclp_tty_input(str, count);
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}
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static inline void sclp_eval_selfdeftextmsg(struct gds_subvector *sv)
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{
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void *end;
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end = (void *) sv + sv->length;
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for (sv = sv + 1; (void *) sv < end; sv = (void *) sv + sv->length)
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if (sv->key == 0x30)
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sclp_get_input(sv);
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}
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static inline void sclp_eval_textcmd(struct gds_vector *v)
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{
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struct gds_subvector *sv;
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void *end;
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end = (void *) v + v->length;
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for (sv = (struct gds_subvector *) (v + 1);
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(void *) sv < end; sv = (void *) sv + sv->length)
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if (sv->key == GDS_KEY_SELFDEFTEXTMSG)
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sclp_eval_selfdeftextmsg(sv);
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}
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static inline void sclp_eval_cpmsu(struct gds_vector *v)
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{
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void *end;
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end = (void *) v + v->length;
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for (v = v + 1; (void *) v < end; v = (void *) v + v->length)
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if (v->gds_id == GDS_ID_TEXTCMD)
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sclp_eval_textcmd(v);
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}
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static inline void sclp_eval_mdsmu(struct gds_vector *v)
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{
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v = sclp_find_gds_vector(v + 1, (void *) v + v->length, GDS_ID_CPMSU);
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if (v)
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sclp_eval_cpmsu(v);
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}
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static void sclp_tty_receiver(struct evbuf_header *evbuf)
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{
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struct gds_vector *v;
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v = sclp_find_gds_vector(evbuf + 1, (void *) evbuf + evbuf->length,
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GDS_ID_MDSMU);
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if (v)
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sclp_eval_mdsmu(v);
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}
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static void
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sclp_tty_state_change(struct sclp_register *reg)
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{
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}
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static struct sclp_register sclp_input_event =
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{
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.receive_mask = EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK,
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.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;
|
|
|
|
/* z/VM multiplexes the line mode output on the 32xx screen */
|
|
if (MACHINE_IS_VM && !CONSOLE_IS_SCLP)
|
|
return 0;
|
|
if (!sclp.has_linemode)
|
|
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);
|
|
timer_setup(&sclp_tty_timer, sclp_tty_timeout, 0);
|
|
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;
|
|
}
|
|
device_initcall(sclp_tty_init);
|