3 files changed, 24 insertions, 2 deletions

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index bd992c0048f0..fbcc00c6c06e 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -178,6 +178,13 @@ config ARCH_HAS_ILOG2_U64
         bool
         default n
 
+config EMULATED_CMPXCHG
+        bool
+        default y
+        help
+          Sparc32 does not have a CAS instruction like sparc64. cmpxchg()
+          is emulated, and therefore it is not completely atomic.
+
 config SUN_PM
         bool
         default y
diff --git a/arch/sparc/kernel/time.c b/arch/sparc/kernel/time.c
index f1401b57ccc7..7b4612da74a6 100644
--- a/arch/sparc/kernel/time.c
+++ b/arch/sparc/kernel/time.c
@@ -148,7 +148,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
 }
 
 /* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
-static void __init kick_start_clock(void)
+static void __devinit kick_start_clock(void)
 {
         struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
         unsigned char sec;
@@ -223,7 +223,7 @@ static __inline__ int has_low_battery(void)
         return (data1 == data2);        /* Was the write blocked? */
 }
 
-static void __init mostek_set_system_time(void)
+static void __devinit mostek_set_system_time(void)
 {
         unsigned int year, mon, day, hour, min, sec;
         struct mostek48t02 *mregs;
diff --git a/arch/sparc/lib/atomic32.c b/arch/sparc/lib/atomic32.c
index 559335f4917d..617d29832e19 100644
--- a/arch/sparc/lib/atomic32.c
+++ b/arch/sparc/lib/atomic32.c
@@ -2,6 +2,7 @@
  * atomic32.c: 32-bit atomic_t implementation
  *
  * Copyright (C) 2004 Keith M Wesolowski
+ * Copyright (C) 2007 Kyle McMartin
  * 
  * Based on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf
  */
@@ -117,3 +118,17 @@ unsigned long ___change_bit(unsigned long *addr, unsigned long mask)
         return old & mask;
 }
 EXPORT_SYMBOL(___change_bit);
+
+unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
+{
+        unsigned long flags;
+        u32 prev;
+
+        spin_lock_irqsave(ATOMIC_HASH(addr), flags);
+        if ((prev = *ptr) == old)
+                *ptr = new;
+        spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
+
+        return (unsigned long)prev;
+}
+EXPORT_SYMBOL(__cmpxchg_u32);