[RFC 20/24] SERIAL: core: add xmit buffer allocation callbacks
From: Russell King <hidden>
Date: 2012-10-06 12:45:47
Also in:
linux-omap, linux-serial
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
This allows drivers (such as OMAP serial) to allocate and free their transmit buffers in a sane manner, rather than working around the buffer allocation provided by serial_core. Signed-off-by: Russell King <redacted> --- drivers/tty/serial/serial_core.c | 23 ++++++++++++++++------- include/linux/serial_core.h | 2 ++ 2 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 4dd609e..53274ae 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c@@ -147,12 +147,18 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, * buffer. */ if (!state->xmit.buf) { - /* This is protected by the per port mutex */ - page = get_zeroed_page(GFP_KERNEL); - if (!page) - return -ENOMEM; + if (uport->ops->alloc_xmit) { + retval = uport->ops->alloc_xmit(uport, &state->xmit); + if (retval) + return retval; + } else { + /* This is protected by the per port mutex */ + page = get_zeroed_page(GFP_KERNEL); + if (!page) + return -ENOMEM; - state->xmit.buf = (unsigned char *) page; + state->xmit.buf = (unsigned char *) page; + } uart_circ_clear(&state->xmit); }
@@ -257,7 +263,10 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) * Free the transmit buffer page. */ if (state->xmit.buf) { - free_page((unsigned long)state->xmit.buf); + if (uport->ops->free_xmit) + uport->ops->free_xmit(uport, &state->xmit); + else + free_page((unsigned long)state->xmit.buf); state->xmit.buf = NULL; } }
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index b17d4c9..ebe9af1 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h@@ -248,6 +248,8 @@ struct uart_ops { void (*break_ctl)(struct uart_port *, int ctl); int (*startup)(struct uart_port *); void (*shutdown)(struct uart_port *); + int (*alloc_xmit)(struct uart_port *, struct circ_buf *); + void (*free_xmit)(struct uart_port *, struct circ_buf *); void (*flush_buffer)(struct uart_port *); void (*set_termios)(struct uart_port *, struct ktermios *new, struct ktermios *old);
--
1.7.4.4