The logic to detect if the irq stack was already in use with
raw_spin_trylock() is wrong, because it will generate a "trylock failure
on UP" error message with CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=y.
arch_spin_trylock() can't be used either since in the CONFIG_SMP=n case
no atomic protection is given and we are reentrant here.
Now we will use a mutex instead, which is safe on UP and SMP.
Counting how often the irq stack was used is pretty useless, so just
drop this piece of code.
Signed-off-by: Helge Deller <deller@xxxxxx>
diff --git a/arch/parisc/include/asm/hardirq.h b/arch/parisc/include/asm/hardirq.h
index 4c6dd8d..241c345 100644
--- a/arch/parisc/include/asm/hardirq.h
+++ b/arch/parisc/include/asm/hardirq.h
@@ -17,13 +17,8 @@
typedef struct {
unsigned int __softirq_pending;
-#ifdef CONFIG_DEBUG_STACKOVERFLOW
unsigned int kernel_stack_usage;
-#ifdef CONFIG_IRQSTACKS
unsigned int irq_stack_usage;
- unsigned int irq_stack_counter;
-#endif
-#endif
#ifdef CONFIG_SMP
unsigned int irq_resched_count;
unsigned int irq_call_count;
diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h
index cfbc439..cc2290a 100644
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -17,7 +17,6 @@
#include <asm/ptrace.h>
#include <asm/types.h>
#include <asm/percpu.h>
-
#endif /* __ASSEMBLY__ */
/*
@@ -59,26 +58,6 @@
#ifndef __ASSEMBLY__
/*
- * IRQ STACK - used for irq handler
- */
-#ifdef __KERNEL__
-
-#include <linux/spinlock_types.h>
-
-#define IRQ_STACK_SIZE (4096 << 2) /* 16k irq stack size */
-
-union irq_stack_union {
- unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)];
- raw_spinlock_t lock;
-};
-
-DECLARE_PER_CPU(union irq_stack_union, irq_stack_union);
-
-void call_on_stack(unsigned long p1, void *func, unsigned long new_stack);
-
-#endif /* __KERNEL__ */
-
-/*
* Data detected about CPUs at boot time which is the same for all CPU's.
* HP boxes are SMP - ie identical processors.
*
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index 9c2d953..88ba8a8 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -27,7 +27,7 @@
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
#include <linux/types.h>
#include <asm/io.h>
@@ -172,10 +172,6 @@ int arch_show_interrupts(struct seq_file *p, int prec)
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_stack_usage);
seq_puts(p, " Interrupt stack usage\n");
- seq_printf(p, "%*s: ", prec, "ISC");
- for_each_online_cpu(j)
- seq_printf(p, "%10u ", irq_stats(j)->irq_stack_counter);
- seq_puts(p, " Interrupt stack usage counter\n");
# endif
#endif
#ifdef CONFIG_SMP
@@ -384,6 +380,23 @@ static inline int eirr_to_irq(unsigned long eirr)
return (BITS_PER_LONG - bit) + TIMER_IRQ;
}
+#ifdef CONFIG_IRQSTACKS
+/*
+ * IRQ STACK - used for irq handler
+ */
+#define IRQ_STACK_SIZE (4096 << 2) /* 16k irq stack size */
+
+union irq_stack_union {
+ unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)];
+ struct mutex lock;
+};
+
+DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = {
+ .lock = __MUTEX_INITIALIZER(irq_stack_union.lock),
+ };
+#endif
+
+
int sysctl_panic_on_stackoverflow = 1;
static inline void stack_overflow_check(struct pt_regs *regs)
@@ -450,15 +463,14 @@ panic_check:
}
#ifdef CONFIG_IRQSTACKS
-DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = {
- .lock = __RAW_SPIN_LOCK_UNLOCKED((irq_stack_union).lock)
- };
+/* in entry.S: */
+void call_on_stack(unsigned long p1, void *func, unsigned long new_stack);
static void execute_on_irq_stack(void *func, unsigned long param1)
{
union irq_stack_union *union_ptr;
unsigned long irq_stack;
- raw_spinlock_t *irq_stack_in_use;
+ struct mutex *irq_stack_in_use;
union_ptr = &per_cpu(irq_stack_union, smp_processor_id());
irq_stack = (unsigned long) &union_ptr->stack;
@@ -470,7 +482,7 @@ static void execute_on_irq_stack(void *func, unsigned long param1)
* the irq stack usage.
*/
irq_stack_in_use = &union_ptr->lock;
- if (!raw_spin_trylock(irq_stack_in_use)) {
+ if (!mutex_trylock(irq_stack_in_use)) {
void (*direct_call)(unsigned long p1) = func;
/* We are using the IRQ stack already.
@@ -482,10 +494,8 @@ static void execute_on_irq_stack(void *func, unsigned long param1)
/* This is where we switch to the IRQ stack. */
call_on_stack(param1, func, irq_stack);
- __inc_irq_stat(irq_stack_counter);
-
/* free up irq stack usage. */
- do_raw_spin_unlock(irq_stack_in_use);
+ mutex_unlock(irq_stack_in_use);
}
asmlinkage void do_softirq(void)
--
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