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path: root/drivers/tty/tty_buffer.c
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Diffstat (limited to 'drivers/tty/tty_buffer.c')
-rw-r--r--drivers/tty/tty_buffer.c132
1 files changed, 76 insertions, 56 deletions
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 6f366f2..ddd74d4 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -29,17 +29,19 @@
void tty_buffer_free_all(struct tty_struct *tty)
{
+ struct tty_bufhead *buf = &tty->buf;
struct tty_buffer *thead;
- while ((thead = tty->buf.head) != NULL) {
- tty->buf.head = thead->next;
+
+ while ((thead = buf->head) != NULL) {
+ buf->head = thead->next;
kfree(thead);
}
- while ((thead = tty->buf.free) != NULL) {
- tty->buf.free = thead->next;
+ while ((thead = buf->free) != NULL) {
+ buf->free = thead->next;
kfree(thead);
}
- tty->buf.tail = NULL;
- tty->buf.memory_used = 0;
+ buf->tail = NULL;
+ buf->memory_used = 0;
}
/**
@@ -87,15 +89,17 @@ static struct tty_buffer *tty_buffer_alloc(struct tty_struct *tty, size_t size)
static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
{
+ struct tty_bufhead *buf = &tty->buf;
+
/* Dumb strategy for now - should keep some stats */
- tty->buf.memory_used -= b->size;
- WARN_ON(tty->buf.memory_used < 0);
+ buf->memory_used -= b->size;
+ WARN_ON(buf->memory_used < 0);
if (b->size >= 512)
kfree(b);
else {
- b->next = tty->buf.free;
- tty->buf.free = b;
+ b->next = buf->free;
+ buf->free = b;
}
}
@@ -112,13 +116,14 @@ static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
static void __tty_buffer_flush(struct tty_struct *tty)
{
+ struct tty_bufhead *buf = &tty->buf;
struct tty_buffer *thead;
- while ((thead = tty->buf.head) != NULL) {
- tty->buf.head = thead->next;
+ while ((thead = buf->head) != NULL) {
+ buf->head = thead->next;
tty_buffer_free(tty, thead);
}
- tty->buf.tail = NULL;
+ buf->tail = NULL;
}
/**
@@ -135,21 +140,23 @@ static void __tty_buffer_flush(struct tty_struct *tty)
void tty_buffer_flush(struct tty_struct *tty)
{
struct tty_port *port = tty->port;
+ struct tty_bufhead *buf = &tty->buf;
unsigned long flags;
- spin_lock_irqsave(&tty->buf.lock, flags);
+
+ spin_lock_irqsave(&buf->lock, flags);
/* If the data is being pushed to the tty layer then we can't
process it here. Instead set a flag and the flush_to_ldisc
path will process the flush request before it exits */
if (test_bit(TTYP_FLUSHING, &port->iflags)) {
set_bit(TTYP_FLUSHPENDING, &port->iflags);
- spin_unlock_irqrestore(&tty->buf.lock, flags);
+ spin_unlock_irqrestore(&buf->lock, flags);
wait_event(tty->read_wait,
test_bit(TTYP_FLUSHPENDING, &port->iflags) == 0);
return;
} else
__tty_buffer_flush(tty);
- spin_unlock_irqrestore(&tty->buf.lock, flags);
+ spin_unlock_irqrestore(&buf->lock, flags);
}
/**
@@ -197,12 +204,14 @@ static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
*/
static int __tty_buffer_request_room(struct tty_struct *tty, size_t size)
{
+ struct tty_bufhead *buf = &tty->buf;
struct tty_buffer *b, *n;
int left;
/* OPTIMISATION: We could keep a per tty "zero" sized buffer to
remove this conditional if its worth it. This would be invisible
to the callers */
- if ((b = tty->buf.tail) != NULL)
+ b = buf->tail;
+ if (b != NULL)
left = b->size - b->used;
else
left = 0;
@@ -214,8 +223,8 @@ static int __tty_buffer_request_room(struct tty_struct *tty, size_t size)
b->next = n;
b->commit = b->used;
} else
- tty->buf.head = n;
- tty->buf.tail = n;
+ buf->head = n;
+ buf->tail = n;
} else
size = left;
}
@@ -262,6 +271,7 @@ EXPORT_SYMBOL_GPL(tty_buffer_request_room);
int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
const unsigned char *chars, char flag, size_t size)
{
+ struct tty_bufhead *buf = &tty->buf;
int copied = 0;
do {
int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
@@ -269,18 +279,18 @@ int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
unsigned long flags;
struct tty_buffer *tb;
- spin_lock_irqsave(&tty->buf.lock, flags);
+ spin_lock_irqsave(&buf->lock, flags);
space = __tty_buffer_request_room(tty, goal);
- tb = tty->buf.tail;
+ tb = buf->tail;
/* If there is no space then tb may be NULL */
if (unlikely(space == 0)) {
- spin_unlock_irqrestore(&tty->buf.lock, flags);
+ spin_unlock_irqrestore(&buf->lock, flags);
break;
}
memcpy(tb->char_buf_ptr + tb->used, chars, space);
memset(tb->flag_buf_ptr + tb->used, flag, space);
tb->used += space;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
+ spin_unlock_irqrestore(&buf->lock, flags);
copied += space;
chars += space;
/* There is a small chance that we need to split the data over
@@ -307,6 +317,7 @@ EXPORT_SYMBOL(tty_insert_flip_string_fixed_flag);
int tty_insert_flip_string_flags(struct tty_struct *tty,
const unsigned char *chars, const char *flags, size_t size)
{
+ struct tty_bufhead *buf = &tty->buf;
int copied = 0;
do {
int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
@@ -314,18 +325,18 @@ int tty_insert_flip_string_flags(struct tty_struct *tty,
unsigned long __flags;
struct tty_buffer *tb;
- spin_lock_irqsave(&tty->buf.lock, __flags);
+ spin_lock_irqsave(&buf->lock, __flags);
space = __tty_buffer_request_room(tty, goal);
- tb = tty->buf.tail;
+ tb = buf->tail;
/* If there is no space then tb may be NULL */
if (unlikely(space == 0)) {
- spin_unlock_irqrestore(&tty->buf.lock, __flags);
+ spin_unlock_irqrestore(&buf->lock, __flags);
break;
}
memcpy(tb->char_buf_ptr + tb->used, chars, space);
memcpy(tb->flag_buf_ptr + tb->used, flags, space);
tb->used += space;
- spin_unlock_irqrestore(&tty->buf.lock, __flags);
+ spin_unlock_irqrestore(&buf->lock, __flags);
copied += space;
chars += space;
flags += space;
@@ -351,12 +362,14 @@ EXPORT_SYMBOL(tty_insert_flip_string_flags);
void tty_schedule_flip(struct tty_struct *tty)
{
+ struct tty_bufhead *buf = &tty->buf;
unsigned long flags;
- spin_lock_irqsave(&tty->buf.lock, flags);
- if (tty->buf.tail != NULL)
- tty->buf.tail->commit = tty->buf.tail->used;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
- schedule_work(&tty->buf.work);
+
+ spin_lock_irqsave(&buf->lock, flags);
+ if (buf->tail != NULL)
+ buf->tail->commit = buf->tail->used;
+ spin_unlock_irqrestore(&buf->lock, flags);
+ schedule_work(&buf->work);
}
EXPORT_SYMBOL(tty_schedule_flip);
@@ -378,20 +391,21 @@ EXPORT_SYMBOL(tty_schedule_flip);
int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
size_t size)
{
+ struct tty_bufhead *buf = &tty->buf;
int space;
unsigned long flags;
struct tty_buffer *tb;
- spin_lock_irqsave(&tty->buf.lock, flags);
+ spin_lock_irqsave(&buf->lock, flags);
space = __tty_buffer_request_room(tty, size);
- tb = tty->buf.tail;
+ tb = buf->tail;
if (likely(space)) {
*chars = tb->char_buf_ptr + tb->used;
memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
tb->used += space;
}
- spin_unlock_irqrestore(&tty->buf.lock, flags);
+ spin_unlock_irqrestore(&buf->lock, flags);
return space;
}
EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
@@ -415,20 +429,21 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
int tty_prepare_flip_string_flags(struct tty_struct *tty,
unsigned char **chars, char **flags, size_t size)
{
+ struct tty_bufhead *buf = &tty->buf;
int space;
unsigned long __flags;
struct tty_buffer *tb;
- spin_lock_irqsave(&tty->buf.lock, __flags);
+ spin_lock_irqsave(&buf->lock, __flags);
space = __tty_buffer_request_room(tty, size);
- tb = tty->buf.tail;
+ tb = buf->tail;
if (likely(space)) {
*chars = tb->char_buf_ptr + tb->used;
*flags = tb->flag_buf_ptr + tb->used;
tb->used += space;
}
- spin_unlock_irqrestore(&tty->buf.lock, __flags);
+ spin_unlock_irqrestore(&buf->lock, __flags);
return space;
}
EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
@@ -452,6 +467,7 @@ static void flush_to_ldisc(struct work_struct *work)
struct tty_struct *tty =
container_of(work, struct tty_struct, buf.work);
struct tty_port *port = tty->port;
+ struct tty_bufhead *buf = &tty->buf;
unsigned long flags;
struct tty_ldisc *disc;
@@ -459,11 +475,11 @@ static void flush_to_ldisc(struct work_struct *work)
if (disc == NULL) /* !TTY_LDISC */
return;
- spin_lock_irqsave(&tty->buf.lock, flags);
+ spin_lock_irqsave(&buf->lock, flags);
if (!test_and_set_bit(TTYP_FLUSHING, &port->iflags)) {
struct tty_buffer *head;
- while ((head = tty->buf.head) != NULL) {
+ while ((head = buf->head) != NULL) {
int count;
char *char_buf;
unsigned char *flag_buf;
@@ -472,7 +488,7 @@ static void flush_to_ldisc(struct work_struct *work)
if (!count) {
if (head->next == NULL)
break;
- tty->buf.head = head->next;
+ buf->head = head->next;
tty_buffer_free(tty, head);
continue;
}
@@ -488,10 +504,10 @@ static void flush_to_ldisc(struct work_struct *work)
char_buf = head->char_buf_ptr + head->read;
flag_buf = head->flag_buf_ptr + head->read;
head->read += count;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
+ spin_unlock_irqrestore(&buf->lock, flags);
disc->ops->receive_buf(tty, char_buf,
flag_buf, count);
- spin_lock_irqsave(&tty->buf.lock, flags);
+ spin_lock_irqsave(&buf->lock, flags);
}
clear_bit(TTYP_FLUSHING, &port->iflags);
}
@@ -503,7 +519,7 @@ static void flush_to_ldisc(struct work_struct *work)
clear_bit(TTYP_FLUSHPENDING, &port->iflags);
wake_up(&tty->read_wait);
}
- spin_unlock_irqrestore(&tty->buf.lock, flags);
+ spin_unlock_irqrestore(&buf->lock, flags);
tty_ldisc_deref(disc);
}
@@ -537,16 +553,18 @@ void tty_flush_to_ldisc(struct tty_struct *tty)
void tty_flip_buffer_push(struct tty_struct *tty)
{
+ struct tty_bufhead *buf = &tty->buf;
unsigned long flags;
- spin_lock_irqsave(&tty->buf.lock, flags);
- if (tty->buf.tail != NULL)
- tty->buf.tail->commit = tty->buf.tail->used;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
+
+ spin_lock_irqsave(&buf->lock, flags);
+ if (buf->tail != NULL)
+ buf->tail->commit = buf->tail->used;
+ spin_unlock_irqrestore(&buf->lock, flags);
if (tty->low_latency)
- flush_to_ldisc(&tty->buf.work);
+ flush_to_ldisc(&buf->work);
else
- schedule_work(&tty->buf.work);
+ schedule_work(&buf->work);
}
EXPORT_SYMBOL(tty_flip_buffer_push);
@@ -562,11 +580,13 @@ EXPORT_SYMBOL(tty_flip_buffer_push);
void tty_buffer_init(struct tty_struct *tty)
{
- spin_lock_init(&tty->buf.lock);
- tty->buf.head = NULL;
- tty->buf.tail = NULL;
- tty->buf.free = NULL;
- tty->buf.memory_used = 0;
- INIT_WORK(&tty->buf.work, flush_to_ldisc);
+ struct tty_bufhead *buf = &tty->buf;
+
+ spin_lock_init(&buf->lock);
+ buf->head = NULL;
+ buf->tail = NULL;
+ buf->free = NULL;
+ buf->memory_used = 0;
+ INIT_WORK(&buf->work, flush_to_ldisc);
}
generated by cgit v0.10.2 at 2024-07-17 00:44:45 (GMT)