diff options
| -rw-r--r-- | drivers/tty/tty_buffer.c | 45 | ||||
| -rw-r--r-- | include/linux/tty.h | 4 | ||||
| -rw-r--r-- | include/linux/tty_flip.h | 8 |
3 files changed, 45 insertions, 12 deletions
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index 08835a6dd022..3002e20e10d7 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -101,6 +101,7 @@ static void tty_buffer_reset(struct tty_buffer *p, size_t size) p->next = NULL; p->commit = 0; p->read = 0; + p->flags = 0; } /** @@ -229,31 +230,49 @@ void tty_buffer_flush(struct tty_struct *tty) * tty_buffer_request_room - grow tty buffer if needed * @tty: tty structure * @size: size desired + * @flags: buffer flags if new buffer allocated (default = 0) * * Make at least size bytes of linear space available for the tty * buffer. If we fail return the size we managed to find. + * + * Will change over to a new buffer if the current buffer is encoded as + * TTY_NORMAL (so has no flags buffer) and the new buffer requires + * a flags buffer. */ -int tty_buffer_request_room(struct tty_port *port, size_t size) +static int __tty_buffer_request_room(struct tty_port *port, size_t size, + int flags) { struct tty_bufhead *buf = &port->buf; struct tty_buffer *b, *n; - int left; + int left, change; b = buf->tail; - left = b->size - b->used; + if (b->flags & TTYB_NORMAL) + left = 2 * b->size - b->used; + else + left = b->size - b->used; - if (left < size) { + change = (b->flags & TTYB_NORMAL) && (~flags & TTYB_NORMAL); + if (change || left < size) { /* This is the slow path - looking for new buffers to use */ if ((n = tty_buffer_alloc(port, size)) != NULL) { + n->flags = flags; buf->tail = n; b->commit = b->used; smp_mb(); b->next = n; - } else + } else if (change) + size = 0; + else size = left; } return size; } + +int tty_buffer_request_room(struct tty_port *port, size_t size) +{ + return __tty_buffer_request_room(port, size, 0); +} EXPORT_SYMBOL_GPL(tty_buffer_request_room); /** @@ -273,12 +292,14 @@ int tty_insert_flip_string_fixed_flag(struct tty_port *port, int copied = 0; do { int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE); - int space = tty_buffer_request_room(port, goal); + int flags = (flag == TTY_NORMAL) ? TTYB_NORMAL : 0; + int space = __tty_buffer_request_room(port, goal, flags); struct tty_buffer *tb = port->buf.tail; if (unlikely(space == 0)) break; memcpy(char_buf_ptr(tb, tb->used), chars, space); - memset(flag_buf_ptr(tb, tb->used), flag, space); + if (~tb->flags & TTYB_NORMAL) + memset(flag_buf_ptr(tb, tb->used), flag, space); tb->used += space; copied += space; chars += space; @@ -361,11 +382,12 @@ EXPORT_SYMBOL(tty_schedule_flip); int tty_prepare_flip_string(struct tty_port *port, unsigned char **chars, size_t size) { - int space = tty_buffer_request_room(port, size); + int space = __tty_buffer_request_room(port, size, TTYB_NORMAL); if (likely(space)) { struct tty_buffer *tb = port->buf.tail; *chars = char_buf_ptr(tb, tb->used); - memset(flag_buf_ptr(tb, tb->used), TTY_NORMAL, space); + if (~tb->flags & TTYB_NORMAL) + memset(flag_buf_ptr(tb, tb->used), TTY_NORMAL, space); tb->used += space; } return space; @@ -378,7 +400,10 @@ receive_buf(struct tty_struct *tty, struct tty_buffer *head, int count) { struct tty_ldisc *disc = tty->ldisc; unsigned char *p = char_buf_ptr(head, head->read); - char *f = flag_buf_ptr(head, head->read); + char *f = NULL; + + if (~head->flags & TTYB_NORMAL) + f = flag_buf_ptr(head, head->read); if (disc->ops->receive_buf2) count = disc->ops->receive_buf2(tty, p, f, count); diff --git a/include/linux/tty.h b/include/linux/tty.h index 38fcc0574ba9..ad98b4376968 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -39,10 +39,14 @@ struct tty_buffer { int size; int commit; int read; + int flags; /* Data points here */ unsigned long data[0]; }; +/* Values for .flags field of tty_buffer */ +#define TTYB_NORMAL 1 /* buffer has no flags buffer */ + static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs) { return ((unsigned char *)b->data) + ofs; diff --git a/include/linux/tty_flip.h b/include/linux/tty_flip.h index 3f821e98af0f..c28dd523f96e 100644 --- a/include/linux/tty_flip.h +++ b/include/linux/tty_flip.h @@ -17,8 +17,12 @@ static inline int tty_insert_flip_char(struct tty_port *port, unsigned char ch, char flag) { struct tty_buffer *tb = port->buf.tail; - if (tb && tb->used < tb->size) { - *flag_buf_ptr(tb, tb->used) = flag; + int change; + + change = (tb->flags & TTYB_NORMAL) && (flag != TTY_NORMAL); + if (!change && tb->used < tb->size) { + if (~tb->flags & TTYB_NORMAL) + *flag_buf_ptr(tb, tb->used) = flag; *char_buf_ptr(tb, tb->used++) = ch; return 1; } |