Use rtc_lock to protect RTC operations

    
Many RTC routines were not protected against each other, so there are
potential races, for example, ntp-update against /dev/rtc.  This patch
fixes them using rtc_lock.
    
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 18 insertions, 0 deletions

diff --git a/arch/mips/momentum/jaguar_atx/setup.c b/arch/mips/momentum/jaguar_atx/setup.c
index 768bf44..bab192d 100644
--- a/arch/mips/momentum/jaguar_atx/setup.c
+++ b/arch/mips/momentum/jaguar_atx/setup.c
@@ -149,7 +149,9 @@ arch_initcall(per_cpu_mappings);
 unsigned long m48t37y_get_time(void)
 {
 	unsigned int year, month, day, hour, min, sec;
+	unsigned long flags;
 
+	spin_lock_irqsave(&rtc_lock, flags);
 	/* stop the update */
 	rtc_base[0x7ff8] = 0x40;
 
@@ -166,6 +168,7 @@ unsigned long m48t37y_get_time(void)
 
 	/* start the update */
 	rtc_base[0x7ff8] = 0x00;
+	spin_unlock_irqrestore(&rtc_lock, flags);
 
 	return mktime(year, month, day, hour, min, sec);
 }
@@ -173,11 +176,13 @@ unsigned long m48t37y_get_time(void)
 int m48t37y_set_time(unsigned long sec)
 {
 	struct rtc_time tm;
+	unsigned long flags;
 
 	/* convert to a more useful format -- note months count from 0 */
 	to_tm(sec, &tm);
 	tm.tm_mon += 1;
 
+	spin_lock_irqsave(&rtc_lock, flags);
 	/* enable writing */
 	rtc_base[0x7ff8] = 0x80;
 
@@ -201,6 +206,7 @@ int m48t37y_set_time(unsigned long sec)
 
 	/* disable writing */
 	rtc_base[0x7ff8] = 0x00;
+	spin_unlock_irqrestore(&rtc_lock, flags);
 
 	return 0;
 }
diff --git a/arch/mips/momentum/ocelot_3/setup.c b/arch/mips/momentum/ocelot_3/setup.c
index a7803e0..c9b7ff8 100644
--- a/arch/mips/momentum/ocelot_3/setup.c
+++ b/arch/mips/momentum/ocelot_3/setup.c
@@ -135,7 +135,9 @@ void setup_wired_tlb_entries(void)
 unsigned long m48t37y_get_time(void)
 {
 	unsigned int year, month, day, hour, min, sec;
+	unsigned long flags;
 
+	spin_lock_irqsave(&rtc_lock, flags);
 	/* stop the update */
 	rtc_base[0x7ff8] = 0x40;
 
@@ -152,6 +154,7 @@ unsigned long m48t37y_get_time(void)
 
 	/* start the update */
 	rtc_base[0x7ff8] = 0x00;
+	spin_unlock_irqrestore(&rtc_lock, flags);
 
 	return mktime(year, month, day, hour, min, sec);
 }
@@ -159,11 +162,13 @@ unsigned long m48t37y_get_time(void)
 int m48t37y_set_time(unsigned long sec)
 {
 	struct rtc_time tm;
+	unsigned long flags;
 
 	/* convert to a more useful format -- note months count from 0 */
 	to_tm(sec, &tm);
 	tm.tm_mon += 1;
 
+	spin_lock_irqsave(&rtc_lock, flags);
 	/* enable writing */
 	rtc_base[0x7ff8] = 0x80;
 
@@ -187,6 +192,7 @@ int m48t37y_set_time(unsigned long sec)
 
 	/* disable writing */
 	rtc_base[0x7ff8] = 0x00;
+	spin_unlock_irqrestore(&rtc_lock, flags);
 
 	return 0;
 }
diff --git a/arch/mips/momentum/ocelot_c/setup.c b/arch/mips/momentum/ocelot_c/setup.c
index ce70fc9..2755c15 100644
--- a/arch/mips/momentum/ocelot_c/setup.c
+++ b/arch/mips/momentum/ocelot_c/setup.c
@@ -140,7 +140,9 @@ unsigned long m48t37y_get_time(void)
 	unsigned char* rtc_base = (unsigned char*)0xfc800000;
 #endif
 	unsigned int year, month, day, hour, min, sec;
+	unsigned long flags;
 
+	spin_lock_irqsave(&rtc_lock, flags);
 	/* stop the update */
 	rtc_base[0x7ff8] = 0x40;
 
@@ -157,6 +159,7 @@ unsigned long m48t37y_get_time(void)
 
 	/* start the update */
 	rtc_base[0x7ff8] = 0x00;
+	spin_unlock_irqrestore(&rtc_lock, flags);
 
 	return mktime(year, month, day, hour, min, sec);
 }
@@ -169,11 +172,13 @@ int m48t37y_set_time(unsigned long sec)
 	unsigned char* rtc_base = (unsigned char*)0xfc800000;
 #endif
 	struct rtc_time tm;
+	unsigned long flags;
 
 	/* convert to a more useful format -- note months count from 0 */
 	to_tm(sec, &tm);
 	tm.tm_mon += 1;
 
+	spin_lock_irqsave(&rtc_lock, flags);
 	/* enable writing */
 	rtc_base[0x7ff8] = 0x80;
 
@@ -197,6 +202,7 @@ int m48t37y_set_time(unsigned long sec)
 
 	/* disable writing */
 	rtc_base[0x7ff8] = 0x00;
+	spin_unlock_irqrestore(&rtc_lock, flags);
 
 	return 0;
 }