From: Russell King <rmk@dyn-67.arm.linux.org.uk>
Date: Mon, 28 Jan 2008 10:16:37 +0000 (+0000)
Subject: [ARM] Fix timer damage from d3d74453c34f8fd87674a8cf5b8a327c68f22e99
X-Git-Tag: v2.6.25-rc1~1175^2~5
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=193c3cc12583344be01206078d9ad3fec5dbc397;p=linux-2.6

[ARM] Fix timer damage from d3d74453c34f8fd87674a8cf5b8a327c68f22e99

Move the xtime write mode seqlock into timer_tick(), so it only
surrounds the call to do_timer().

This avoids a deadlock in update_process_times() ...
hrtimer_get_softirq_time() which tries to get a read mode seqlock
on xtime, thereby preventing booting.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index e59b5b8416..b5867eca1d 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -325,7 +325,9 @@ void timer_tick(void)
 	profile_tick(CPU_PROFILING);
 	do_leds();
 	do_set_rtc();
+	write_seqlock(&xtime_lock);
 	do_timer(1);
+	write_sequnlock(&xtime_lock);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(get_irq_regs()));
 #endif
diff --git a/arch/arm/mach-aaec2000/core.c b/arch/arm/mach-aaec2000/core.c
index 0446ef2f5b..b016be2b0e 100644
--- a/arch/arm/mach-aaec2000/core.c
+++ b/arch/arm/mach-aaec2000/core.c
@@ -130,13 +130,9 @@ static irqreturn_t
 aaec2000_timer_interrupt(int irq, void *dev_id)
 {
 	/* TODO: Check timer accuracy */
-	write_seqlock(&xtime_lock);
-
 	timer_tick();
 	TIMER1_CLEAR = 1;
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-clps711x/time.c b/arch/arm/mach-clps711x/time.c
index f428af7545..e5dc33f1f9 100644
--- a/arch/arm/mach-clps711x/time.c
+++ b/arch/arm/mach-clps711x/time.c
@@ -50,9 +50,7 @@ static unsigned long clps711x_gettimeoffset(void)
 static irqreturn_t
 p720t_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
 	timer_tick();
-	write_sequnlock(&xtime_lock);
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-clps7500/core.c b/arch/arm/mach-clps7500/core.c
index 986205ec92..2ac63671ea 100644
--- a/arch/arm/mach-clps7500/core.c
+++ b/arch/arm/mach-clps7500/core.c
@@ -298,8 +298,6 @@ extern unsigned long ioc_timer_gettimeoffset(void);
 static irqreturn_t
 clps7500_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	timer_tick();
 
 	/* Why not using do_leds interface?? */
@@ -313,8 +311,6 @@ clps7500_timer_interrupt(int irq, void *dev_id)
 		}
 	}
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-ebsa110/core.c b/arch/arm/mach-ebsa110/core.c
index 8c1b5690df..7710e14b52 100644
--- a/arch/arm/mach-ebsa110/core.c
+++ b/arch/arm/mach-ebsa110/core.c
@@ -178,8 +178,6 @@ ebsa110_timer_interrupt(int irq, void *dev_id)
 {
 	u32 count;
 
-	write_seqlock(&xtime_lock);
-
 	/* latch and read timer 1 */
 	__raw_writeb(0x40, PIT_CTRL);
 	count = __raw_readb(PIT_T1);
@@ -192,8 +190,6 @@ ebsa110_timer_interrupt(int irq, void *dev_id)
 
 	timer_tick();
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
index 70b2c78011..f1074ff02f 100644
--- a/arch/arm/mach-ep93xx/core.c
+++ b/arch/arm/mach-ep93xx/core.c
@@ -99,8 +99,6 @@ static unsigned int last_jiffy_time;
 
 static int ep93xx_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	__raw_writel(1, EP93XX_TIMER1_CLEAR);
 	while ((signed long)
 		(__raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time)
@@ -109,8 +107,6 @@ static int ep93xx_timer_interrupt(int irq, void *dev_id)
 		timer_tick();
 	}
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-footbridge/dc21285-timer.c b/arch/arm/mach-footbridge/dc21285-timer.c
index 3a63941d43..b2a21189dd 100644
--- a/arch/arm/mach-footbridge/dc21285-timer.c
+++ b/arch/arm/mach-footbridge/dc21285-timer.c
@@ -30,14 +30,10 @@ static unsigned long timer1_gettimeoffset (void)
 static irqreturn_t
 timer1_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	*CSR_TIMER1_CLR = 0;
 
 	timer_tick();
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-footbridge/isa-timer.c b/arch/arm/mach-footbridge/isa-timer.c
index d08d64139d..a764e01d35 100644
--- a/arch/arm/mach-footbridge/isa-timer.c
+++ b/arch/arm/mach-footbridge/isa-timer.c
@@ -64,9 +64,7 @@ static unsigned long isa_gettimeoffset(void)
 static irqreturn_t
 isa_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
 	timer_tick();
-	write_sequnlock(&xtime_lock);
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-h720x/cpu-h7201.c b/arch/arm/mach-h720x/cpu-h7201.c
index 9107b8e2ad..c2a431f482 100644
--- a/arch/arm/mach-h720x/cpu-h7201.c
+++ b/arch/arm/mach-h720x/cpu-h7201.c
@@ -29,13 +29,9 @@
 static irqreturn_t
 h7201_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	CPU_REG (TIMER_VIRT, TIMER_TOPSTAT);
 	timer_tick();
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-h720x/cpu-h7202.c b/arch/arm/mach-h720x/cpu-h7202.c
index 0a1a25fb8b..c627fa124e 100644
--- a/arch/arm/mach-h720x/cpu-h7202.c
+++ b/arch/arm/mach-h720x/cpu-h7202.c
@@ -113,9 +113,7 @@ h7202_timerx_demux_handler(unsigned int irq_unused, struct irq_desc *desc)
 	mask = CPU_REG (TIMER_VIRT, TIMER_TOPSTAT);
 
 	if ( mask & TSTAT_T0INT ) {
-		write_seqlock(&xtime_lock);
 		timer_tick();
-		write_sequnlock(&xtime_lock);
 		if( mask == TSTAT_T0INT )
 			return;
 	}
diff --git a/arch/arm/mach-integrator/core.c b/arch/arm/mach-integrator/core.c
index e9c82deb79..7fbbc17f8e 100644
--- a/arch/arm/mach-integrator/core.c
+++ b/arch/arm/mach-integrator/core.c
@@ -250,8 +250,6 @@ unsigned long integrator_gettimeoffset(void)
 static irqreturn_t
 integrator_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	/*
 	 * clear the interrupt
 	 */
@@ -259,8 +257,6 @@ integrator_timer_interrupt(int irq, void *dev_id)
 
 	timer_tick();
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-ixp2000/core.c b/arch/arm/mach-ixp2000/core.c
index cb6ad21188..81cdc82672 100644
--- a/arch/arm/mach-ixp2000/core.c
+++ b/arch/arm/mach-ixp2000/core.c
@@ -206,8 +206,6 @@ unsigned long ixp2000_gettimeoffset (void)
 
 static int ixp2000_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	/* clear timer 1 */
 	ixp2000_reg_wrb(IXP2000_T1_CLR, 1);
 
@@ -217,8 +215,6 @@ static int ixp2000_timer_interrupt(int irq, void *dev_id)
 		next_jiffy_time -= ticks_per_jiffy;
 	}
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-ks8695/time.c b/arch/arm/mach-ks8695/time.c
index d2c86e4a72..02f766b312 100644
--- a/arch/arm/mach-ks8695/time.c
+++ b/arch/arm/mach-ks8695/time.c
@@ -70,10 +70,7 @@ static unsigned long ks8695_gettimeoffset (void)
  */
 static irqreturn_t ks8695_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
 	timer_tick();
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-lh7a40x/time.c b/arch/arm/mach-lh7a40x/time.c
index c25316d025..e50e60b338 100644
--- a/arch/arm/mach-lh7a40x/time.c
+++ b/arch/arm/mach-lh7a40x/time.c
@@ -41,13 +41,9 @@
 static irqreturn_t
 lh7a40x_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	TIMER_EOI = 0;
 	timer_tick();
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-mx3/time.c b/arch/arm/mach-mx3/time.c
index e81fb5c5d7..fb565c98db 100644
--- a/arch/arm/mach-mx3/time.c
+++ b/arch/arm/mach-mx3/time.c
@@ -45,8 +45,6 @@ static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id)
 {
 	unsigned int next_match;
 
-	write_seqlock(&xtime_lock);
-
 	if (__raw_readl(MXC_GPT_GPTSR) & GPTSR_OF1) {
 		do {
 			timer_tick();
@@ -57,8 +55,6 @@ static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id)
 				       __raw_readl(MXC_GPT_GPTCNT)) <= 0);
 	}
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-netx/time.c b/arch/arm/mach-netx/time.c
index 4762e207b0..ea07b54afa 100644
--- a/arch/arm/mach-netx/time.c
+++ b/arch/arm/mach-netx/time.c
@@ -33,12 +33,8 @@
 static irqreturn_t
 netx_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	timer_tick();
 
-	write_sequnlock(&xtime_lock);
-
 	/* acknowledge interrupt */
 	writel(COUNTER_BIT(0), NETX_GPIO_IRQ);
 
diff --git a/arch/arm/mach-omap2/timer-gp.c b/arch/arm/mach-omap2/timer-gp.c
index 8d322c20cc..3234deedb9 100644
--- a/arch/arm/mach-omap2/timer-gp.c
+++ b/arch/arm/mach-omap2/timer-gp.c
@@ -40,13 +40,9 @@ static inline void omap2_gp_timer_start(unsigned long load_val)
 
 static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	omap_dm_timer_write_status(gptimer, OMAP_TIMER_INT_OVERFLOW);
 	timer_tick();
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-pnx4008/time.c b/arch/arm/mach-pnx4008/time.c
index 67e05f005a..6d4ca8fc0c 100644
--- a/arch/arm/mach-pnx4008/time.c
+++ b/arch/arm/mach-pnx4008/time.c
@@ -51,8 +51,6 @@ static irqreturn_t pnx4008_timer_interrupt(int irq, void *dev_id)
 {
 	if (__raw_readl(HSTIM_INT) & MATCH0_INT) {
 
-		write_seqlock(&xtime_lock);
-
 		do {
 			timer_tick();
 
@@ -73,8 +71,6 @@ static irqreturn_t pnx4008_timer_interrupt(int irq, void *dev_id)
 		} while ((signed)
 			 (__raw_readl(HSTIM_MATCH0) -
 			  __raw_readl(HSTIM_COUNTER)) < 0);
-
-		write_sequnlock(&xtime_lock);
 	}
 
 	return IRQ_HANDLED;
diff --git a/arch/arm/mach-realview/core.c b/arch/arm/mach-realview/core.c
index c7f1b44da4..61d70218f1 100644
--- a/arch/arm/mach-realview/core.c
+++ b/arch/arm/mach-realview/core.c
@@ -530,8 +530,6 @@ static unsigned long realview_gettimeoffset(void)
  */
 static irqreturn_t realview_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
-
 	// ...clear the interrupt
 	writel(1, TIMER0_VA_BASE + TIMER_INTCLR);
 
@@ -542,8 +540,6 @@ static irqreturn_t realview_timer_interrupt(int irq, void *dev_id)
 	update_process_times(user_mode(get_irq_regs()));
 #endif
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c
index fdf7b016e7..47f8640438 100644
--- a/arch/arm/mach-sa1100/time.c
+++ b/arch/arm/mach-sa1100/time.c
@@ -62,8 +62,6 @@ sa1100_timer_interrupt(int irq, void *dev_id)
 {
 	unsigned int next_match;
 
-	write_seqlock(&xtime_lock);
-
 #ifdef CONFIG_NO_IDLE_HZ
 	if (match_posponed) {
 		match_posponed = 0;
@@ -85,8 +83,6 @@ sa1100_timer_interrupt(int irq, void *dev_id)
 		next_match = (OSMR0 += LATCH);
 	} while ((signed long)(next_match - OSCR) <= 0);
 
-	write_sequnlock(&xtime_lock);
-
 	return IRQ_HANDLED;
 }
 
diff --git a/arch/arm/mach-shark/core.c b/arch/arm/mach-shark/core.c
index a0545db2a3..09d9f33d40 100644
--- a/arch/arm/mach-shark/core.c
+++ b/arch/arm/mach-shark/core.c
@@ -82,9 +82,7 @@ static void __init shark_map_io(void)
 static irqreturn_t
 shark_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
 	timer_tick();
-	write_sequnlock(&xtime_lock);
 	return IRQ_HANDLED;
 }