Merge tag 'tty-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver patches from Greg KH:
 "Here's the big tty/serial driver pull request for 3.12-rc1.

  Lots of n_tty reworks to resolve some very long-standing issues,
  removing the 3-4 different locks that were taken for every character.
  This code has been beaten on for a long time in linux-next with no
  reported regressions.

  Other than that, a range of serial and tty driver updates and
  revisions.  Full details in the shortlog"

* tag 'tty-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (226 commits)
  hvc_xen: Remove unnecessary __GFP_ZERO from kzalloc
  serial: imx: initialize the local variable
  tty: ar933x_uart: add device tree support and binding documentation
  tty: ar933x_uart: allow to build the driver as a module
  ARM: dts: msm: Update uartdm compatible strings
  devicetree: serial: Document msm_serial bindings
  serial: unify serial bindings into a single dir
  serial: fsl-imx-uart: Cleanup duplicate device tree binding
  tty: ar933x_uart: use config_enabled() macro to clean up ifdefs
  tty: ar933x_uart: remove superfluous assignment of ar933x_uart_driver.nr
  tty: ar933x_uart: use the clk API to get the uart clock
  tty: serial: cpm_uart: Adding proper request of GPIO used by cpm_uart driver
  serial: sirf: fix the amount of serial ports
  serial: sirf: define macro for some magic numbers of USP
  serial: icom: move array overflow checks earlier
  TTY: amiserial, remove unnecessary platform_set_drvdata()
  serial: st-asc: remove unnecessary platform_set_drvdata()
  msm_serial: Send more than 1 character on the console w/ UARTDM
  msm_serial: Add support for non-GSBI UARTDM devices
  msm_serial: Switch clock consumer strings and simplify code
  ...

79 files changed, 6422 insertions, 2917 deletions

diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index 083710e0236..2b86f8e0fb5 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -1785,8 +1785,6 @@ static int __exit amiga_serial_remove(struct platform_device *pdev)
 	free_irq(IRQ_AMIGA_TBE, state);
 	free_irq(IRQ_AMIGA_RBF, state);
 
-	platform_set_drvdata(pdev, NULL);
-
 	return error;
 }
 
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index eb255e807c0..9eba119bcdd 100644
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c
@@ -361,7 +361,12 @@ static int hvc_open(struct tty_struct *tty, struct file * filp)
 		tty->driver_data = NULL;
 		tty_port_put(&hp->port);
 		printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc);
-	}
+	} else
+		/* We are ready... raise DTR/RTS */
+		if (C_BAUD(tty))
+			if (hp->ops->dtr_rts)
+				hp->ops->dtr_rts(hp, 1);
+
 	/* Force wakeup of the polling thread */
 	hvc_kick();
 
@@ -393,6 +398,10 @@ static void hvc_close(struct tty_struct *tty, struct file * filp)
 		/* We are done with the tty pointer now. */
 		tty_port_tty_set(&hp->port, NULL);
 
+		if (C_HUPCL(tty))
+			if (hp->ops->dtr_rts)
+				hp->ops->dtr_rts(hp, 0);
+
 		if (hp->ops->notifier_del)
 			hp->ops->notifier_del(hp, hp->data);
 
diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h
index 674d23cb919..91310198082 100644
--- a/drivers/tty/hvc/hvc_console.h
+++ b/drivers/tty/hvc/hvc_console.h
@@ -75,6 +75,9 @@ struct hv_ops {
 	/* tiocmget/set implementation */
 	int (*tiocmget)(struct hvc_struct *hp);
 	int (*tiocmset)(struct hvc_struct *hp, unsigned int set, unsigned int clear);
+
+	/* Callbacks to handle tty ports */
+	void (*dtr_rts)(struct hvc_struct *hp, int raise);
 };
 
 /* Register a vterm and a slot index for use as a console (console_init) */
diff --git a/drivers/tty/hvc/hvc_iucv.c b/drivers/tty/hvc/hvc_iucv.c
index 9d47f50c275..fd17a9b804b 100644
--- a/drivers/tty/hvc/hvc_iucv.c
+++ b/drivers/tty/hvc/hvc_iucv.c
@@ -656,21 +656,64 @@ static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
 }
 
 /**
+ * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS
+ * @hp:		Pointer the HVC device (struct hvc_struct)
+ * @raise:	Non-zero to raise or zero to lower DTR/RTS lines
+ *
+ * This routine notifies the HVC back-end to raise or lower DTR/RTS
+ * lines.  Raising DTR/RTS is ignored.  Lowering DTR/RTS indicates to
+ * drop the IUCV connection (similar to hang up the modem).
+ */
+static void hvc_iucv_dtr_rts(struct hvc_struct *hp, int raise)
+{
+	struct hvc_iucv_private *priv;
+	struct iucv_path        *path;
+
+	/* Raising the DTR/RTS is ignored as IUCV connections can be
+	 * established at any times.
+	 */
+	if (raise)
+		return;
+
+	priv = hvc_iucv_get_private(hp->vtermno);
+	if (!priv)
+		return;
+
+	/* Lowering the DTR/RTS lines disconnects an established IUCV
+	 * connection.
+	 */
+	flush_sndbuf_sync(priv);
+
+	spin_lock_bh(&priv->lock);
+	path = priv->path;		/* save reference to IUCV path */
+	priv->path = NULL;
+	priv->iucv_state = IUCV_DISCONN;
+	spin_unlock_bh(&priv->lock);
+
+	/* Sever IUCV path outside of priv->lock due to lock ordering of:
+	 * priv->lock <--> iucv_table_lock */
+	if (path) {
+		iucv_path_sever(path, NULL);
+		iucv_path_free(path);
+	}
+}
+
+/**
  * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
  * @hp:		Pointer to the HVC device (struct hvc_struct)
  * @id:		Additional data (originally passed to hvc_alloc):
  *		the index of an struct hvc_iucv_private instance.
  *
  * This routine notifies the HVC back-end that the last tty device fd has been
- * closed.  The function calls hvc_iucv_cleanup() to clean up the struct
- * hvc_iucv_private instance.
+ * closed.  The function cleans up tty resources.  The clean-up of the IUCV
+ * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios
+ * control setting.
  *
  * Locking:	struct hvc_iucv_private->lock
  */
 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
 {
 	struct hvc_iucv_private *priv;
-	struct iucv_path	*path;
 
 	priv = hvc_iucv_get_private(id);
 	if (!priv)
@@ -679,17 +722,11 @@ static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
 	flush_sndbuf_sync(priv);
 
 	spin_lock_bh(&priv->lock);
-	path = priv->path;		/* save reference to IUCV path */
-	priv->path = NULL;
-	hvc_iucv_cleanup(priv);
+	destroy_tty_buffer_list(&priv->tty_outqueue);
+	destroy_tty_buffer_list(&priv->tty_inqueue);
+	priv->tty_state = TTY_CLOSED;
+	priv->sndbuf_len = 0;
 	spin_unlock_bh(&priv->lock);
-
-	/* sever IUCV path outside of priv->lock due to lock ordering of:
-	 * priv->lock <--> iucv_table_lock */
-	if (path) {
-		iucv_path_sever(path, NULL);
-		iucv_path_free(path);
-	}
 }
 
 /**
@@ -931,6 +968,7 @@ static const struct hv_ops hvc_iucv_ops = {
 	.notifier_add = hvc_iucv_notifier_add,
 	.notifier_del = hvc_iucv_notifier_del,
 	.notifier_hangup = hvc_iucv_notifier_hangup,
+	.dtr_rts = hvc_iucv_dtr_rts,
 };
 
 /* Suspend / resume device operations */
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 682210d778b..e61c36cbb86 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -208,7 +208,7 @@ static int xen_hvm_console_init(void)
 
 	info = vtermno_to_xencons(HVC_COOKIE);
 	if (!info) {
-		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
 		if (!info)
 			return -ENOMEM;
 	} else if (info->intf != NULL) {
@@ -257,7 +257,7 @@ static int xen_pv_console_init(void)
 
 	info = vtermno_to_xencons(HVC_COOKIE);
 	if (!info) {
-		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
 		if (!info)
 			return -ENOMEM;
 	} else if (info->intf != NULL) {
@@ -284,7 +284,7 @@ static int xen_initial_domain_console_init(void)
 
 	info = vtermno_to_xencons(HVC_COOKIE);
 	if (!info) {
-		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
 		if (!info)
 			return -ENOMEM;
 	}
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 642239015b4..c0f76da5530 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -807,7 +807,7 @@ static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
 	int h = dlci->adaption - 1;
 
 	total_size = 0;
-	while(1) {
+	while (1) {
 		len = kfifo_len(dlci->fifo);
 		if (len == 0)
 			return total_size;
@@ -827,8 +827,8 @@ static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
 		switch (dlci->adaption) {
 		case 1:	/* Unstructured */
 			break;
-		case 2:	/* Unstructed with modem bits. Always one byte as we never
-			   send inline break data */
+		case 2:	/* Unstructed with modem bits.
+		Always one byte as we never send inline break data */
 			*dp++ = gsm_encode_modem(dlci);
 			break;
 		}
@@ -968,7 +968,7 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
 	unsigned long flags;
 	int sweep;
 
-	if (dlci->constipated) 
+	if (dlci->constipated)
 		return;
 
 	spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
@@ -981,7 +981,7 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
 			gsm_dlci_data_output(dlci->gsm, dlci);
 	}
 	if (sweep)
- 		gsm_dlci_data_sweep(dlci->gsm);
+		gsm_dlci_data_sweep(dlci->gsm);
 	spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
 }
 
@@ -1138,7 +1138,7 @@ static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen)
 static void gsm_control_rls(struct gsm_mux *gsm, u8 *data, int clen)
 {
 	struct tty_port *port;
-	unsigned int addr = 0 ;
+	unsigned int addr = 0;
 	u8 bits;
 	int len = clen;
 	u8 *dp = data;
@@ -1740,10 +1740,11 @@ static void gsm_queue(struct gsm_mux *gsm)
 
 	if ((gsm->control & ~PF) == UI)
 		gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len);
-	if (gsm->encoding == 0){
-		/* WARNING: gsm->received_fcs is used for gsm->encoding = 0 only.
-		            In this case it contain the last piece of data
-		            required to generate final CRC */
+	if (gsm->encoding == 0) {
+		/* WARNING: gsm->received_fcs is used for
+		gsm->encoding = 0 only.
+		In this case it contain the last piece of data
+		required to generate final CRC */
 		gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs);
 	}
 	if (gsm->fcs != GOOD_FCS) {
@@ -2904,9 +2905,11 @@ static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty)
 	gsm = gsm_mux[mux];
 	if (gsm->dead)
 		return -EL2HLT;
-	/* If DLCI 0 is not yet fully open return an error. This is ok from a locking
-	   perspective as we don't have to worry about this if DLCI0 is lost */
-	if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN) 
+	/* If DLCI 0 is not yet fully open return an error.
+	This is ok from a locking
+	perspective as we don't have to worry about this
+	if DLCI0 is lost */
+	if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN)
 		return -EL2NSYNC;
 	dlci = gsm->dlci[line];
 	if (dlci == NULL) {
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 4bf0fc0843d..c9a9ddd1d0b 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -50,6 +50,7 @@
 #include <linux/uaccess.h>
 #include <linux/module.h>
 #include <linux/ratelimit.h>
+#include <linux/vmalloc.h>
 
 
 /* number of characters left in xmit buffer before select has we have room */
@@ -74,37 +75,81 @@
 #define ECHO_OP_SET_CANON_COL 0x81
 #define ECHO_OP_ERASE_TAB 0x82
 
+#define ECHO_COMMIT_WATERMARK	256
+#define ECHO_BLOCK		256
+#define ECHO_DISCARD_WATERMARK	N_TTY_BUF_SIZE - (ECHO_BLOCK + 32)
+
+
+#undef N_TTY_TRACE
+#ifdef N_TTY_TRACE
+# define n_tty_trace(f, args...)	trace_printk(f, ##args)
+#else
+# define n_tty_trace(f, args...)
+#endif
+
 struct n_tty_data {
-	unsigned int column;
+	/* producer-published */
+	size_t read_head;
+	size_t canon_head;
+	size_t echo_head;
+	size_t echo_commit;
+	DECLARE_BITMAP(char_map, 256);
+
+	/* private to n_tty_receive_overrun (single-threaded) */
 	unsigned long overrun_time;
 	int num_overrun;
 
+	/* non-atomic */
+	bool no_room;
+
+	/* must hold exclusive termios_rwsem to reset these */
 	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
-	unsigned char echo_overrun:1;
 
-	DECLARE_BITMAP(process_char_map, 256);
+	/* shared by producer and consumer */
+	char read_buf[N_TTY_BUF_SIZE];
 	DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE);
+	unsigned char echo_buf[N_TTY_BUF_SIZE];
 
-	char *read_buf;
-	int read_head;
-	int read_tail;
-	int read_cnt;
 	int minimum_to_wake;
 
-	unsigned char *echo_buf;
-	unsigned int echo_pos;
-	unsigned int echo_cnt;
+	/* consumer-published */
+	size_t read_tail;
+	size_t line_start;
 
-	int canon_data;
-	unsigned long canon_head;
+	/* protected by output lock */
+	unsigned int column;
 	unsigned int canon_column;
+	size_t echo_tail;
 
 	struct mutex atomic_read_lock;
 	struct mutex output_lock;
-	struct mutex echo_lock;
-	raw_spinlock_t read_lock;
 };
 
+static inline size_t read_cnt(struct n_tty_data *ldata)
+{
+	return ldata->read_head - ldata->read_tail;
+}
+
+static inline unsigned char read_buf(struct n_tty_data *ldata, size_t i)
+{
+	return ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)];
+}
+
+static inline unsigned char *read_buf_addr(struct n_tty_data *ldata, size_t i)
+{
+	return &ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)];
+}
+
+static inline unsigned char echo_buf(struct n_tty_data *ldata, size_t i)
+{
+	return ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)];
+}
+
+static inline unsigned char *echo_buf_addr(struct n_tty_data *ldata, size_t i)
+{
+	return &ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)];
+}
+
 static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
 			       unsigned char __user *ptr)
 {
@@ -114,33 +159,18 @@ static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
 	return put_user(x, ptr);
 }
 
-/**
- *	n_tty_set_room	-	receive space
- *	@tty: terminal
- *
- *	Updates tty->receive_room to reflect the currently available space
- *	in the input buffer, and re-schedules the flip buffer work if space
- *	just became available.
- *
- *	Locks: Concurrent update is protected with read_lock
- */
-
-static int set_room(struct tty_struct *tty)
+static int receive_room(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
 	int left;
-	int old_left;
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&ldata->read_lock, flags);
 
 	if (I_PARMRK(tty)) {
 		/* Multiply read_cnt by 3, since each byte might take up to
 		 * three times as many spaces when PARMRK is set (depending on
 		 * its flags, e.g. parity error). */
-		left = N_TTY_BUF_SIZE - ldata->read_cnt * 3 - 1;
+		left = N_TTY_BUF_SIZE - read_cnt(ldata) * 3 - 1;
 	} else
-		left = N_TTY_BUF_SIZE