[RFC][PATCH 1/2] Fix many ARM timer handlers

From: Peter Zijlstra
Date: Mon Jan 28 2008 - 05:41:27 EST


From: Russell King <rmk@xxxxxxxxxxxxxxxx>

Mostly untested patch: 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.

Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
---
arch/arm/kernel/time.c | 2 ++
arch/arm/mach-aaec2000/core.c | 4 ----
arch/arm/mach-clps711x/time.c | 2 --
arch/arm/mach-clps7500/core.c | 4 ----
arch/arm/mach-ebsa110/core.c | 4 ----
arch/arm/mach-ep93xx/core.c | 4 ----
arch/arm/mach-footbridge/dc21285-timer.c | 4 ----
arch/arm/mach-footbridge/isa-timer.c | 2 --
arch/arm/mach-h720x/cpu-h7201.c | 4 ----
arch/arm/mach-h720x/cpu-h7202.c | 2 --
arch/arm/mach-integrator/core.c | 4 ----
arch/arm/mach-ixp2000/core.c | 4 ----
arch/arm/mach-ks8695/time.c | 3 ---
arch/arm/mach-lh7a40x/time.c | 4 ----
arch/arm/mach-mx3/time.c | 4 ----
arch/arm/mach-netx/time.c | 4 ----
arch/arm/mach-omap2/timer-gp.c | 4 ----
arch/arm/mach-pnx4008/time.c | 4 ----
arch/arm/mach-realview/core.c | 4 ----
arch/arm/mach-sa1100/time.c | 4 ----
arch/arm/mach-shark/core.c | 2 --
21 files changed, 2 insertions(+), 71 deletions(-)

Index: linux-2.6/arch/arm/kernel/time.c
===================================================================
--- linux-2.6.orig/arch/arm/kernel/time.c
+++ linux-2.6/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
Index: linux-2.6/arch/arm/mach-aaec2000/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-aaec2000/core.c
+++ linux-2.6/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;
}

Index: linux-2.6/arch/arm/mach-clps711x/time.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-clps711x/time.c
+++ linux-2.6/arch/arm/mach-clps711x/time.c
@@ -50,9 +50,7 @@ static unsigned long clps711x_gettimeoff
static irqreturn_t
p720t_timer_interrupt(int irq, void *dev_id)
{
- write_seqlock(&xtime_lock);
timer_tick();
- write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-clps7500/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-clps7500/core.c
+++ linux-2.6/arch/arm/mach-clps7500/core.c
@@ -298,8 +298,6 @@ extern unsigned long ioc_timer_gettimeof
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 *
}
}

- write_sequnlock(&xtime_lock);
-
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-ebsa110/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-ebsa110/core.c
+++ linux-2.6/arch/arm/mach-ebsa110/core.c
@@ -178,8 +178,6 @@ ebsa110_timer_interrupt(int irq, void *d
{
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 *d

timer_tick();

- write_sequnlock(&xtime_lock);
-
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-ep93xx/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-ep93xx/core.c
+++ linux-2.6/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 ir
timer_tick();
}

- write_sequnlock(&xtime_lock);
-
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-footbridge/dc21285-timer.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-footbridge/dc21285-timer.c
+++ linux-2.6/arch/arm/mach-footbridge/dc21285-timer.c
@@ -30,14 +30,10 @@ static unsigned long timer1_gettimeoffse
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;
}

Index: linux-2.6/arch/arm/mach-footbridge/isa-timer.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-footbridge/isa-timer.c
+++ linux-2.6/arch/arm/mach-footbridge/isa-timer.c
@@ -64,9 +64,7 @@ static unsigned long isa_gettimeoffset(v
static irqreturn_t
isa_timer_interrupt(int irq, void *dev_id)
{
- write_seqlock(&xtime_lock);
timer_tick();
- write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-h720x/cpu-h7201.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-h720x/cpu-h7201.c
+++ linux-2.6/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;
}

Index: linux-2.6/arch/arm/mach-h720x/cpu-h7202.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-h720x/cpu-h7202.c
+++ linux-2.6/arch/arm/mach-h720x/cpu-h7202.c
@@ -113,9 +113,7 @@ h7202_timerx_demux_handler(unsigned int
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;
}
Index: linux-2.6/arch/arm/mach-integrator/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-integrator/core.c
+++ linux-2.6/arch/arm/mach-integrator/core.c
@@ -250,8 +250,6 @@ unsigned long integrator_gettimeoffset(v
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

timer_tick();

- write_sequnlock(&xtime_lock);
-
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-ixp2000/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-ixp2000/core.c
+++ linux-2.6/arch/arm/mach-ixp2000/core.c
@@ -206,8 +206,6 @@ unsigned long ixp2000_gettimeoffset (voi

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 i
next_jiffy_time -= ticks_per_jiffy;
}

- write_sequnlock(&xtime_lock);
-
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-ks8695/time.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-ks8695/time.c
+++ linux-2.6/arch/arm/mach-ks8695/time.c
@@ -70,10 +70,7 @@ static unsigned long ks8695_gettimeoffse
*/
static irqreturn_t ks8695_timer_interrupt(int irq, void *dev_id)
{
- write_seqlock(&xtime_lock);
timer_tick();
- write_sequnlock(&xtime_lock);
-
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-lh7a40x/time.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-lh7a40x/time.c
+++ linux-2.6/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;
}

Index: linux-2.6/arch/arm/mach-mx3/time.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-mx3/time.c
+++ linux-2.6/arch/arm/mach-mx3/time.c
@@ -45,8 +45,6 @@ static irqreturn_t mxc_timer_interrupt(i
{
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(i
__raw_readl(MXC_GPT_GPTCNT)) <= 0);
}

- write_sequnlock(&xtime_lock);
-
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-netx/time.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-netx/time.c
+++ linux-2.6/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);

Index: linux-2.6/arch/arm/mach-omap2/timer-gp.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-omap2/timer-gp.c
+++ linux-2.6/arch/arm/mach-omap2/timer-gp.c
@@ -40,13 +40,9 @@ static inline void omap2_gp_timer_start(

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;
}

Index: linux-2.6/arch/arm/mach-pnx4008/time.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-pnx4008/time.c
+++ linux-2.6/arch/arm/mach-pnx4008/time.c
@@ -51,8 +51,6 @@ static irqreturn_t pnx4008_timer_interru
{
if (__raw_readl(HSTIM_INT) & MATCH0_INT) {

- write_seqlock(&xtime_lock);
-
do {
timer_tick();

@@ -73,8 +71,6 @@ static irqreturn_t pnx4008_timer_interru
} while ((signed)
(__raw_readl(HSTIM_MATCH0) -
__raw_readl(HSTIM_COUNTER)) < 0);
-
- write_sequnlock(&xtime_lock);
}

return IRQ_HANDLED;
Index: linux-2.6/arch/arm/mach-realview/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-realview/core.c
+++ linux-2.6/arch/arm/mach-realview/core.c
@@ -530,8 +530,6 @@ static unsigned long realview_gettimeoff
*/
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_interr
update_process_times(user_mode(get_irq_regs()));
#endif

- write_sequnlock(&xtime_lock);
-
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-sa1100/time.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-sa1100/time.c
+++ linux-2.6/arch/arm/mach-sa1100/time.c
@@ -62,8 +62,6 @@ sa1100_timer_interrupt(int irq, void *de
{
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 *de
next_match = (OSMR0 += LATCH);
} while ((signed long)(next_match - OSCR) <= 0);

- write_sequnlock(&xtime_lock);
-
return IRQ_HANDLED;
}

Index: linux-2.6/arch/arm/mach-shark/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-shark/core.c
+++ linux-2.6/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;
}


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