From: Jiri Slaby <jslaby@suse.cz>
To: gregkh@linuxfoundation.org
Cc: alan@linux.intel.com, linux-kernel@vger.kernel.org, jirislaby@gmail.com
Subject: [PATCH 19/21] TTY: tty_buffer, cache pointer to tty->buf
Date: Thu, 18 Oct 2012 22:26:45 +0200 [thread overview]
Message-ID: <1350592007-9216-20-git-send-email-jslaby@suse.cz> (raw)
In-Reply-To: <1350592007-9216-1-git-send-email-jslaby@suse.cz>
During the move of tty buffers from tty_struct to tty_port, we will
need to switch all users of buf to tty->port->buf. There are many
functions where this is accessed directly in their code many times.
Cache the tty->buf pointer in such functions now and change only
single lines in each function in the next patch.
Not that it is convenient for the next patch, but the code is now also
more readable.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/tty/tty_buffer.c | 132 +++++++++++++++++++++++++++--------------------
1 file changed, 76 insertions(+), 56 deletions(-)
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index ab3d5c3..ffaa441 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;
@@ -349,12 +360,14 @@ 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);
@@ -376,20 +389,21 @@ 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);
@@ -413,20 +427,21 @@ 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);
@@ -450,6 +465,7 @@ 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;
@@ -457,11 +473,11 @@ 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;
@@ -470,7 +486,7 @@ 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;
}
@@ -486,10 +502,10 @@ 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);
}
@@ -501,7 +517,7 @@ 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);
}
@@ -534,16 +550,18 @@ 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);
@@ -559,11 +577,13 @@ 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);
}
--
1.7.12.3
next prev parent reply other threads:[~2012-10-18 20:28 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-18 20:26 [PATCH 00/21] TTY buffer in tty_port and other stuff Jiri Slaby
2012-10-18 20:26 ` [PATCH 01/21] TTY: devpts, don't care about TTY in devpts_get_tty Jiri Slaby
2012-10-18 20:26 ` [PATCH 02/21] TTY: devpts, return created inode from devpts_pty_new Jiri Slaby
2012-10-18 20:26 ` [PATCH 03/21] TTY: devpts, do not set driver_data Jiri Slaby
2012-10-18 20:26 ` [PATCH 04/21] TTY: devpts, document devpts inode operations Jiri Slaby
2012-10-18 20:26 ` [PATCH 05/21] TTY: move devpts kill to pty Jiri Slaby
2012-10-18 20:26 ` [PATCH 06/21] TTY: vt, fix paste_selection ldisc handling Jiri Slaby
2012-10-18 20:26 ` [PATCH 07/21] TTY: ldisc, wait for idle ldisc in release Jiri Slaby
2012-10-18 20:26 ` [PATCH 08/21] TTY: hci_ldisc, remove invalid check in open Jiri Slaby
2012-10-18 20:47 ` Marcel Holtmann
2012-10-18 20:26 ` [PATCH 09/21] TTY: n_tty, simplify read_buf+echo_buf allocation Jiri Slaby
2012-10-18 20:26 ` [PATCH 10/21] TTY: n_tty, remove bogus checks Jiri Slaby
2012-10-18 20:26 ` [PATCH 11/21] TTY: audit, stop accessing tty->icount Jiri Slaby
2012-10-18 20:26 ` [PATCH 12/21] TTY: n_tty, add ldisc data to n_tty Jiri Slaby
2012-10-18 20:26 ` [PATCH 13/21] TTY: move ldisc data from tty_struct: simple members Jiri Slaby
2012-10-18 20:26 ` [PATCH 14/21] TTY: move ldisc data from tty_struct: bitmaps Jiri Slaby
2012-10-18 20:26 ` [PATCH 15/21] TTY: move ldisc data from tty_struct: read_* and echo_* and canon_* stuff Jiri Slaby
2012-10-18 20:26 ` [PATCH 16/21] TTY: move ldisc data from tty_struct: locks Jiri Slaby
2012-10-18 20:26 ` [PATCH 17/21] TTY: n_tty, propagate n_tty_data Jiri Slaby
2012-10-18 20:26 ` [PATCH 18/21] TTY: move TTY_FLUSH* flags to tty_port Jiri Slaby
2012-10-18 20:26 ` Jiri Slaby [this message]
2012-10-18 20:26 ` [PATCH 20/21] TTY: add port -> tty link Jiri Slaby
2012-10-18 20:26 ` [PATCH 21/21] TTY: move tty buffers to tty_port Jiri Slaby
2012-10-25 18:02 ` Sasha Levin
2012-10-25 18:08 ` Greg KH
2012-10-31 12:53 ` Jiri Slaby
2012-10-31 15:30 ` Sasha Levin
2012-10-31 15:32 ` Jiri Slaby
2012-10-31 15:59 ` Sasha Levin
2012-11-02 15:51 ` Jiri Slaby
2012-11-02 16:07 ` Sasha Levin
2012-11-02 16:18 ` Jiri Slaby
2012-11-02 16:23 ` Sasha Levin
2012-11-03 2:03 ` Sasha Levin
2012-11-03 15:55 ` Jiri Slaby
2012-11-03 23:06 ` Sasha Levin
2012-11-04 0:53 ` Sasha Levin
2012-11-27 19:57 ` Peter Hurley
2012-11-30 23:52 ` Sasha Levin
2012-12-01 14:59 ` flush_to_ldisc accesses tty after free (was: [PATCH 21/21] TTY: move tty buffers to tty_port) Peter Hurley
2012-12-01 20:06 ` Peter Hurley
2012-12-02 19:57 ` Peter Hurley
2012-12-04 19:21 ` Ilya Zykov
2012-10-31 20:10 ` [PATCH 21/21] TTY: move tty buffers to tty_port Sasha Levin
2012-10-18 21:12 ` [PATCH 00/21] TTY buffer in tty_port and other stuff Greg KH
2012-10-22 14:57 ` Alan Cox
2012-10-22 23:59 ` Greg KH
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