[SERIAL]: Fix console write locking in sparc drivers.

Mirror the logic in 8250 for proper console write locking
when SYSRQ is triggered or an OOPS is in progress.

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 68 insertions, 12 deletions

diff --git a/drivers/serial/sunhv.c b/drivers/serial/sunhv.c
index 96557e6dba60..17bcca53d6a1 100644
--- a/drivers/serial/sunhv.c
+++ b/drivers/serial/sunhv.c
@@ -440,8 +440,16 @@ static void sunhv_console_write_paged(struct console *con, const char *s, unsign
 {
         struct uart_port *port = sunhv_port;
         unsigned long flags;
+        int locked = 1;
+
+        local_irq_save(flags);
+        if (port->sysrq) {
+                locked = 0;
+        } else if (oops_in_progress) {
+                locked = spin_trylock(&port->lock);
+        } else
+                spin_lock(&port->lock);
 
-        spin_lock_irqsave(&port->lock, flags);
         while (n > 0) {
                 unsigned long ra = __pa(con_write_page);
                 unsigned long page_bytes;
@@ -469,7 +477,10 @@ static void sunhv_console_write_paged(struct console *con, const char *s, unsign
                         ra += written;
                 }
         }
-        spin_unlock_irqrestore(&port->lock, flags);
+
+        if (locked)
+                spin_unlock(&port->lock);
+        local_irq_restore(flags);
 }
 
 static inline void sunhv_console_putchar(struct uart_port *port, char c)
@@ -488,7 +499,15 @@ static void sunhv_console_write_bychar(struct console *con, const char *s, unsig
 {
         struct uart_port *port = sunhv_port;
         unsigned long flags;
-        int i;
+        int i, locked = 1;
+
+        local_irq_save(flags);
+        if (port->sysrq) {
+                locked = 0;
+        } else if (oops_in_progress) {
+                locked = spin_trylock(&port->lock);
+        } else
+                spin_lock(&port->lock);
 
         spin_lock_irqsave(&port->lock, flags);
         for (i = 0; i < n; i++) {
@@ -496,7 +515,10 @@ static void sunhv_console_write_bychar(struct console *con, const char *s, unsig
                         sunhv_console_putchar(port, '\r');
                 sunhv_console_putchar(port, *s++);
         }
-        spin_unlock_irqrestore(&port->lock, flags);
+
+        if (locked)
+                spin_unlock(&port->lock);
+        local_irq_restore(flags);
 }
 
 static struct console sunhv_console = {
diff --git a/drivers/serial/sunsab.c b/drivers/serial/sunsab.c
index deb9ab4b5a0b..8a0f9e4408d4 100644
--- a/drivers/serial/sunsab.c
+++ b/drivers/serial/sunsab.c
@@ -860,22 +860,31 @@ static int num_channels;
 static void sunsab_console_putchar(struct uart_port *port, int c)
 {
         struct uart_sunsab_port *up = (struct uart_sunsab_port *)port;
-        unsigned long flags;
-
-        spin_lock_irqsave(&up->port.lock, flags);
 
         sunsab_tec_wait(up);
         writeb(c, &up->regs->w.tic);
-
-        spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
 {
         struct uart_sunsab_port *up = &sunsab_ports[con->index];
+        unsigned long flags;
+        int locked = 1;
+
+        local_irq_save(flags);
+        if (up->port.sysrq) {
+                locked = 0;
+        } else if (oops_in_progress) {
+                locked = spin_trylock(&up->port.lock);
+        } else
+                spin_lock(&up->port.lock);
 
         uart_console_write(&up->port, s, n, sunsab_console_putchar);
         sunsab_tec_wait(up);
+
+        if (locked)
+                spin_unlock(&up->port.lock);
+        local_irq_restore(flags);
 }
 
 static int sunsab_console_setup(struct console *con, char *options)
diff --git a/drivers/serial/sunsu.c b/drivers/serial/sunsu.c
index 2a63cdba3208..26d720baf88c 100644
--- a/drivers/serial/sunsu.c
+++ b/drivers/serial/sunsu.c
@@ -1288,7 +1288,17 @@ static void sunsu_console_write(struct console *co, const char *s,
                                 unsigned int count)
 {
         struct uart_sunsu_port *up = &sunsu_ports[co->index];
+        unsigned long flags;
         unsigned int ier;
+        int locked = 1;
+
+        local_irq_save(flags);
+        if (up->port.sysrq) {
+                locked = 0;
+        } else if (oops_in_progress) {
+                locked = spin_trylock(&up->port.lock);
+        } else
+                spin_lock(&up->port.lock);
 
         /*
          *      First save the UER then disable the interrupts
@@ -1304,6 +1314,10 @@ static void sunsu_console_write(struct console *co, const char *s,
          */
         wait_for_xmitr(up);
         serial_out(up, UART_IER, ier);
+
+        if (locked)
+                spin_unlock(&up->port.lock);
+        local_irq_restore(flags);
 }
 
 /*
diff --git a/drivers/serial/sunzilog.c b/drivers/serial/sunzilog.c
index 15b6e1cb040b..0a3e10a4a35d 100644
--- a/drivers/serial/sunzilog.c
+++ b/drivers/serial/sunzilog.c
@@ -9,7 +9,7 @@
  * C. Dost, Pete Zaitcev, Ted Ts'o and Alex Buell for their
  * work there.
  *
- *  Copyright (C) 2002, 2006 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 2002, 2006, 2007 David S. Miller (davem@davemloft.net)
  */
 
 #include <linux/module.h>
@@ -1151,11 +1151,22 @@ sunzilog_console_write(struct console *con, const char *s, unsigned int count)
 {
         struct uart_sunzilog_port *up = &sunzilog_port_table[con->index];
         unsigned long flags;
+        int locked = 1;
+
+        local_irq_save(flags);
+        if (up->port.sysrq) {
+                locked = 0;
+        } else if (oops_in_progress) {
+                locked = spin_trylock(&up->port.lock);
+        } else
+                spin_lock(&up->port.lock);
 
-        spin_lock_irqsave(&up->port.lock, flags);
         uart_console_write(&up->port, s, count, sunzilog_putchar);
         udelay(2);
-        spin_unlock_irqrestore(&up->port.lock, flags);
+
+        if (locked)
+                spin_unlock(&up->port.lock);
+        local_irq_restore(flags);
 }
 
 static int __init sunzilog_console_setup(struct console *con, char *options)