/*
* 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/tty_flip.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:
tty_insert_flip_char(sclp_tty, cchar, TTY_NORMAL);
tty_flip_buffer_push(sclp_tty);
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_tty, buf, count);
tty_insert_flip_char(sclp_tty, '\n', TTY_NORMAL);
} else
tty_insert_flip_string(sclp_tty, buf, count - 2);
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);
