line_interrupt(line->driver->read_irq, arg, NULL);
}
-static int write_room(struct line *dev)
+/* Returns the free space inside the ring buffer of this line.
+ *
+ * Should be called while holding line->lock (this does not modify datas).
+ */
+static int write_room(struct line *line)
{
int n;
- if (dev->buffer == NULL)
- return (LINE_BUFSIZE - 1);
+ if (line->buffer == NULL)
+ return LINE_BUFSIZE - 1;
+
+ /* This is for the case where the buffer is wrapped! */
+ n = line->head - line->tail;
- n = dev->head - dev->tail;
if (n <= 0)
- n = LINE_BUFSIZE + n;
- return (n - 1);
+ n = LINE_BUFSIZE + n; /* The other case */
+ return n - 1;
+}
+
+int line_write_room(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+ unsigned long flags;
+ int room;
+
+ if (tty->stopped)
+ return 0;
+
+ spin_lock_irqsave(&line->lock, flags);
+ room = write_room(line);
+ spin_unlock_irqrestore(&line->lock, flags);
+
+ /*XXX: Warning to remove */
+ if (0 == room)
+ printk(KERN_DEBUG "%s: %s: no room left in buffer\n",
+ __FUNCTION__,tty->name);
+ return room;
}
+int line_chars_in_buffer(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&line->lock, flags);
+
+ /*write_room subtracts 1 for the needed NULL, so we readd it.*/
+ ret = LINE_BUFSIZE - (write_room(line) + 1);
+ spin_unlock_irqrestore(&line->lock, flags);
+
+ return ret;
+}
+
+/*
+ * This copies the content of buf into the circular buffer associated with
+ * this line.
+ * The return value is the number of characters actually copied, i.e. the ones
+ * for which there was space: this function is not supposed to ever flush out
+ * the circular buffer.
+ *
+ * Must be called while holding line->lock!
+ */
static int buffer_data(struct line *line, const char *buf, int len)
{
int end, room;
len = (len > room) ? room : len;
end = line->buffer + LINE_BUFSIZE - line->tail;
- if(len < end){
+
+ if (len < end){
memcpy(line->tail, buf, len);
line->tail += len;
- }
- else {
+ } else {
+ /* The circular buffer is wrapping */
memcpy(line->tail, buf, end);
buf += end;
memcpy(line->buffer, buf, len - end);
line->tail = line->buffer + len - end;
}
- return(len);
+ return len;
}
+/*
+ * Flushes the ring buffer to the output channels. That is, write_chan is
+ * called, passing it line->head as buffer, and an appropriate count.
+ *
+ * On exit, returns 1 when the buffer is empty,
+ * 0 when the buffer is not empty on exit,
+ * and -errno when an error occurred.
+ *
+ * Must be called while holding line->lock!*/
static int flush_buffer(struct line *line)
{
int n, count;
if ((line->buffer == NULL) || (line->head == line->tail))
- return(1);
+ return 1;
if (line->tail < line->head) {
+ /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
count = line->buffer + LINE_BUFSIZE - line->head;
+
n = write_chan(&line->chan_list, line->head, count,
line->driver->write_irq);
if (n < 0)
- return(n);
- if (n == count)
+ return n;
+ if (n == count) {
+ /* We have flushed from ->head to buffer end, now we
+ * must flush only from the beginning to ->tail.*/
line->head = line->buffer;
- else {
+ } else {
line->head += n;
- return(0);
+ return 0;
}
}
count = line->tail - line->head;
n = write_chan(&line->chan_list, line->head, count,
line->driver->write_irq);
- if(n < 0) return(n);
+
+ if(n < 0)
+ return n;
line->head += n;
- return(line->head == line->tail);
+ return line->head == line->tail;
+}
+
+void line_flush_buffer(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+ unsigned long flags;
+ int err;
+
+ /*XXX: copied from line_write, verify if it is correct!*/
+ if(tty->stopped)
+ return;
+ //return 0;
+
+ spin_lock_irqsave(&line->lock, flags);
+ err = flush_buffer(line);
+ /*if (err == 1)
+ err = 0;*/
+ spin_unlock_irqrestore(&line->lock, flags);
+ //return err;
+}
+
+/* We map both ->flush_chars and ->put_char (which go in pair) onto ->flush_buffer
+ * and ->write. Hope it's not that bad.*/
+void line_flush_chars(struct tty_struct *tty)
+{
+ line_flush_buffer(tty);
+}
+
+void line_put_char(struct tty_struct *tty, unsigned char ch)
+{
+ line_write(tty, &ch, sizeof(ch));
}
int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
unsigned long flags;
int n, err, ret = 0;
- if(tty->stopped) return 0;
+ if(tty->stopped)
+ return 0;
- down(&line->sem);
- if(line->head != line->tail){
- local_irq_save(flags);
+ spin_lock_irqsave(&line->lock, flags);
+ if (line->head != line->tail) {
ret = buffer_data(line, buf, len);
err = flush_buffer(line);
- local_irq_restore(flags);
- if(err <= 0 && (err != -EAGAIN || !ret))
+ if (err <= 0 && (err != -EAGAIN || !ret))
ret = err;
- }
- else {
+ } else {
n = write_chan(&line->chan_list, buf, len,
line->driver->write_irq);
- if(n < 0){
+ if (n < 0) {
ret = n;
goto out_up;
}
len -= n;
ret += n;
- if(len > 0)
+ if (len > 0)
ret += buffer_data(line, buf + n, len);
}
- out_up:
- up(&line->sem);
- return(ret);
-}
-
-void line_put_char(struct tty_struct *tty, unsigned char ch)
-{
- line_write(tty, &ch, sizeof(ch));
+out_up:
+ spin_unlock_irqrestore(&line->lock, flags);
+ return ret;
}
void line_set_termios(struct tty_struct *tty, struct termios * old)
/* nothing */
}
-int line_chars_in_buffer(struct tty_struct *tty)
-{
- return 0;
-}
-
static struct {
int cmd;
char *level;
ret = -ENOIOCTLCMD;
break;
}
- return(ret);
+ return ret;
}
static irqreturn_t line_write_interrupt(int irq, void *data,
struct line *line = tty->driver_data;
int err;
+ /* Interrupts are enabled here because we registered the interrupt with
+ * SA_INTERRUPT (see line_setup_irq).*/
+
+ spin_lock_irq(&line->lock);
err = flush_buffer(line);
- if(err == 0)
- return(IRQ_NONE);
- else if(err < 0){
+ if (err == 0) {
+ return IRQ_NONE;
+ } else if(err < 0) {
line->head = line->buffer;
line->tail = line->buffer;
}
+ spin_unlock_irq(&line->lock);
if(tty == NULL)
- return(IRQ_NONE);
+ return IRQ_NONE;
- if(test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
+ if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
(tty->ldisc.write_wakeup != NULL))
(tty->ldisc.write_wakeup)(tty);
* writes.
*/
- if(waitqueue_active(&tty->write_wait))
+ if (waitqueue_active(&tty->write_wait))
wake_up_interruptible(&tty->write_wait);
- return(IRQ_HANDLED);
+ return IRQ_HANDLED;
}
int line_setup_irq(int fd, int input, int output, struct tty_struct *tty)
struct line_driver *driver = line->driver;
int err = 0, flags = SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM;
- if(input) err = um_request_irq(driver->read_irq, fd, IRQ_READ,
+ if (input)
+ err = um_request_irq(driver->read_irq, fd, IRQ_READ,
line_interrupt, flags,
driver->read_irq_name, tty);
- if(err) return(err);
- if(output) err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
+ if (err)
+ return err;
+ if (output)
+ err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
line_write_interrupt, flags,
driver->write_irq_name, tty);
line->have_irq = 1;
- return(err);
+ return err;
}
void line_disable(struct tty_struct *tty, int current_irq)
line = &lines[tty->index];
tty->driver_data = line;
- down(&line->sem);
+ /* The IRQ which takes this lock is not yet enabled and won't be run
+ * before the end, so we don't need to use spin_lock_irq.*/
+ spin_lock(&line->lock);
if (tty->count == 1) {
if (!line->valid) {
err = -ENODEV;
err = open_chan(&line->chan_list);
if(err) goto out;
}
+ /* Here the interrupt is registered.*/
enable_chan(&line->chan_list, tty);
INIT_WORK(&line->task, line_timer_cb, tty);
}
line->count++;
out:
- up(&line->sem);
- return(err);
+ spin_unlock(&line->lock);
+ return err;
}
void line_close(struct tty_struct *tty, struct file * filp)
{
struct line *line = tty->driver_data;
- down(&line->sem);
+ /* XXX: I assume this should be called in process context, not with interrupt
+ * disabled!*/
+ spin_lock_irq(&line->lock);
+
+ /* We ignore the error anyway! */
+ flush_buffer(line);
+
line->count--;
if (tty->count == 1) {
line_disable(tty, -1);
tty->driver_data = NULL;
}
- up(&line->sem);
+ spin_unlock_irq(&line->lock);
}
void close_lines(struct line *lines, int nlines)
close_chan(&lines[i].chan_list);
}
-int line_setup(struct line *lines, int num, char *init, int all_allowed)
+/* Common setup code for both startup command line and mconsole initialization.
+ * @lines contains the the array (of size @num) to modify;
+ * @init is the setup string;
+ * @all_allowed is a boolean saying if we can setup the whole @lines
+ * at once. For instance, it will be usually true for startup init. (where we
+ * can use con=xterm) and false for mconsole.*/
+
+int line_setup(struct line *lines, unsigned int num, char *init, int all_allowed)
{
int i, n;
char *end;
- if(*init == '=') n = -1;
- else {
+ if(*init == '=') {
+ /* We said con=/ssl= instead of con#=, so we are configuring all
+ * consoles at once.*/
+ n = -1;
+ } else {
n = simple_strtoul(init, &end, 0);
if(*end != '='){
printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
init);
- return(0);
+ return 0;
}
init = end;
}
init++;
- if((n >= 0) && (n >= num)){
+
+ if (n >= (signed int) num) {
printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
n, num - 1);
- return(0);
- }
- else if (n >= 0){
+ return 0;
+ } else if (n >= 0){
if (lines[n].count > 0) {
printk("line_setup - device %d is open\n", n);
- return(0);
+ return 0;
}
if (lines[n].init_pri <= INIT_ONE){
lines[n].init_pri = INIT_ONE;
lines[n].valid = 1;
}
}
- }
- else if(!all_allowed){
+ } else if(!all_allowed){
printk("line_setup - can't configure all devices from "
"mconsole\n");
- return(0);
- }
- else {
+ return 0;
+ } else {
for(i = 0; i < num; i++){
if(lines[i].init_pri <= INIT_ALL){
lines[i].init_pri = INIT_ALL;
}
}
}
- return(1);
+ return 1;
}
-int line_config(struct line *lines, int num, char *str)
+int line_config(struct line *lines, unsigned int num, char *str)
{
char *new = uml_strdup(str);
if(new == NULL){
printk("line_config - uml_strdup failed\n");
- return(-ENOMEM);
+ return -ENOMEM;
}
- return(!line_setup(lines, num, new, 0));
+ return !line_setup(lines, num, new, 0);
}
-int line_get_config(char *name, struct line *lines, int num, char *str,
+int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
int size, char **error_out)
{
struct line *line;
dev = simple_strtoul(name, &end, 0);
if((*end != '\0') || (end == name)){
*error_out = "line_get_config failed to parse device number";
- return(0);
+ return 0;
}
if((dev < 0) || (dev >= num)){
- *error_out = "device number of of range";
- return(0);
+ *error_out = "device number out of range";
+ return 0;
}
line = &lines[dev];
- down(&line->sem);
+ spin_lock(&line->lock);
if(!line->valid)
CONFIG_CHUNK(str, size, n, "none", 1);
else if(line->count == 0)
CONFIG_CHUNK(str, size, n, line->init_str, 1);
else n = chan_config_string(&line->chan_list, str, size, error_out);
- up(&line->sem);
+ spin_unlock(&line->lock);
- return(n);
+ return n;
}
-int line_remove(struct line *lines, int num, char *str)
+int line_remove(struct line *lines, unsigned int num, char *str)
{
char config[sizeof("conxxxx=none\0")];
sprintf(config, "%s=none", str);
- return(!line_setup(lines, num, config, 0));
-}
-
-int line_write_room(struct tty_struct *tty)
-{
- struct line *dev = tty->driver_data;
- int room;
-
- if (tty->stopped)
- return 0;
- room = write_room(dev);
- if (0 == room)
- printk(KERN_DEBUG "%s: %s: no room left in buffer\n",
- __FUNCTION__,tty->name);
- return room;
+ return !line_setup(lines, num, config, 0);
}
struct tty_driver *line_register_devfs(struct lines *set,
for(i = 0; i < nlines; i++){
line = &lines[i];
INIT_LIST_HEAD(&line->chan_list);
- sema_init(&line->sem, 1);
+ spin_lock_init(&line->lock);
if(line->init_str != NULL){
line->init_str = uml_strdup(line->init_str);
if(line->init_str == NULL)
"errno = %d\n", -err);
printk("fd %d is losing SIGWINCH support\n",
winch->tty_fd);
- return(IRQ_HANDLED);
+ return IRQ_HANDLED;
}
goto out;
}
out:
if(winch->fd != -1)
reactivate_fd(winch->fd, WINCH_IRQ);
- return(IRQ_HANDLED);
+ return IRQ_HANDLED;
}
DECLARE_MUTEX(winch_handler_sem);
.pid = pid,
.tty = tty });
list_add(&winch->list, &winch_handlers);
- if(um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
+ if(um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
"winch", winch) < 0)
printk("register_winch_irq - failed to register IRQ\n");
int len;
umid = get_umid(1);
- if(umid == NULL) return(base);
+ if(umid == NULL)
+ return base;
len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
title = kmalloc(len, GFP_KERNEL);
if(title == NULL){
printk("Failed to allocate buffer for xterm title\n");
- return(base);
+ return base;
}
snprintf(title, len, "%s (%s)", base, umid);
- return(title);
+ return title;
}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only. This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
#include "linux/workqueue.h"
#include "linux/tty.h"
#include "linux/interrupt.h"
-#include "asm/semaphore.h"
+#include "linux/spinlock.h"
#include "chan_user.h"
#include "mconsole_kern.h"
struct list_head chan_list;
int valid;
int count;
- struct semaphore sem;
+ /*This lock is actually, mostly, local to*/
+ spinlock_t lock;
+
+ /* Yes, this is a real circular buffer.
+ * XXX: And this should become a struct kfifo!
+ *
+ * buffer points to a buffer allocated on demand, of length
+ * LINE_BUFSIZE, head to the start of the ring, tail to the end.*/
char *buffer;
char *head;
char *tail;
+
int sigio;
struct work_struct task;
struct line_driver *driver;
init_pri : INIT_STATIC, \
chan_list : { }, \
valid : 1, \
- sem : { }, \
buffer : NULL, \
head : NULL, \
tail : NULL, \
extern void line_close(struct tty_struct *tty, struct file * filp);
extern int line_open(struct line *lines, struct tty_struct *tty,
struct chan_opts *opts);
-extern int line_setup(struct line *lines, int num, char *init,
+extern int line_setup(struct line *lines, unsigned int sizeof_lines, char *init,
int all_allowed);
extern int line_write(struct tty_struct *tty, const unsigned char *buf, int len);
extern void line_put_char(struct tty_struct *tty, unsigned char ch);
extern void line_set_termios(struct tty_struct *tty, struct termios * old);
extern int line_chars_in_buffer(struct tty_struct *tty);
+extern void line_flush_buffer(struct tty_struct *tty);
+extern void line_flush_chars(struct tty_struct *tty);
extern int line_write_room(struct tty_struct *tty);
extern int line_ioctl(struct tty_struct *tty, struct file * file,
unsigned int cmd, unsigned long arg);
+
extern char *add_xterm_umid(char *base);
extern int line_setup_irq(int fd, int input, int output, struct tty_struct *tty);
extern void line_close_chan(struct line *line);
int nlines);
extern void lines_init(struct line *lines, int nlines);
extern void close_lines(struct line *lines, int nlines);
-extern int line_config(struct line *lines, int num, char *str);
-extern int line_remove(struct line *lines, int num, char *str);
-extern int line_get_config(char *dev, struct line *lines, int num, char *str,
+
+extern int line_config(struct line *lines, unsigned int sizeof_lines, char *str);
+extern int line_remove(struct line *lines, unsigned int sizeof_lines, char *str);
+extern int line_get_config(char *dev, struct line *lines, unsigned int sizeof_lines, char *str,
int size, char **error_out);
#endif
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only. This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff