summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--arch/parisc/Kconfig2
-rw-r--r--arch/parisc/include/asm/hardirq.h9
-rw-r--r--arch/parisc/include/asm/processor.h3
-rw-r--r--arch/parisc/kernel/irq.c101
-rw-r--r--arch/parisc/mm/init.c4
5 files changed, 102 insertions, 17 deletions
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index cad060f288cf..6507dabdd5dd 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -245,7 +245,7 @@ config SMP
config IRQSTACKS
bool "Use separate kernel stacks when processing interrupts"
- default n
+ default y
help
If you say Y here the kernel will use separate kernel stacks
for handling hard and soft interrupts. This can help avoid
diff --git a/arch/parisc/include/asm/hardirq.h b/arch/parisc/include/asm/hardirq.h
index 12373c4dabab..c19f7138ba48 100644
--- a/arch/parisc/include/asm/hardirq.h
+++ b/arch/parisc/include/asm/hardirq.h
@@ -11,10 +11,18 @@
#include <linux/threads.h>
#include <linux/irq.h>
+#ifdef CONFIG_IRQSTACKS
+#define __ARCH_HAS_DO_SOFTIRQ
+#endif
+
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;
@@ -28,6 +36,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
#define __ARCH_IRQ_STAT
#define __IRQ_STAT(cpu, member) (irq_stat[cpu].member)
#define inc_irq_stat(member) this_cpu_inc(irq_stat.member)
+#define __inc_irq_stat(member) __this_cpu_inc(irq_stat.member)
#define local_softirq_pending() this_cpu_read(irq_stat.__softirq_pending)
#define __ARCH_SET_SOFTIRQ_PENDING
diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h
index 064015547d1e..cfbc43929cf6 100644
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -63,10 +63,13 @@
*/
#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);
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index e255db0bb761..55237a70e197 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -166,22 +166,32 @@ int arch_show_interrupts(struct seq_file *p, int prec)
seq_printf(p, "%*s: ", prec, "STK");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->kernel_stack_usage);
- seq_printf(p, " Kernel stack usage\n");
+ seq_puts(p, " Kernel stack usage\n");
+# ifdef CONFIG_IRQSTACKS
+ seq_printf(p, "%*s: ", prec, "IST");
+ 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
seq_printf(p, "%*s: ", prec, "RES");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
- seq_printf(p, " Rescheduling interrupts\n");
+ seq_puts(p, " Rescheduling interrupts\n");
seq_printf(p, "%*s: ", prec, "CAL");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
- seq_printf(p, " Function call interrupts\n");
+ seq_puts(p, " Function call interrupts\n");
#endif
seq_printf(p, "%*s: ", prec, "TLB");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
- seq_printf(p, " TLB shootdowns\n");
+ seq_puts(p, " TLB shootdowns\n");
return 0;
}
@@ -378,6 +388,7 @@ static inline void stack_overflow_check(struct pt_regs *regs)
unsigned long sp = regs->gr[30];
unsigned long stack_usage;
unsigned int *last_usage;
+ int cpu = smp_processor_id();
/* if sr7 != 0, we interrupted a userspace process which we do not want
* to check for stack overflow. We will only check the kernel stack. */
@@ -386,7 +397,31 @@ static inline void stack_overflow_check(struct pt_regs *regs)
/* calculate kernel stack usage */
stack_usage = sp - stack_start;
- last_usage = &per_cpu(irq_stat.kernel_stack_usage, smp_processor_id());
+#ifdef CONFIG_IRQSTACKS
+ if (likely(stack_usage <= THREAD_SIZE))
+ goto check_kernel_stack; /* found kernel stack */
+
+ /* check irq stack usage */
+ stack_start = (unsigned long) &per_cpu(irq_stack_union, cpu).stack;
+ stack_usage = sp - stack_start;
+
+ last_usage = &per_cpu(irq_stat.irq_stack_usage, cpu);
+ if (unlikely(stack_usage > *last_usage))
+ *last_usage = stack_usage;
+
+ if (likely(stack_usage < (IRQ_STACK_SIZE - STACK_MARGIN)))
+ return;
+
+ pr_emerg("stackcheck: %s will most likely overflow irq stack "
+ "(sp:%lx, stk bottom-top:%lx-%lx)\n",
+ current->comm, sp, stack_start, stack_start + IRQ_STACK_SIZE);
+ goto panic_check;
+
+check_kernel_stack:
+#endif
+
+ /* check kernel stack usage */
+ last_usage = &per_cpu(irq_stat.kernel_stack_usage, cpu);
if (unlikely(stack_usage > *last_usage))
*last_usage = stack_usage;
@@ -398,31 +433,69 @@ static inline void stack_overflow_check(struct pt_regs *regs)
"(sp:%lx, stk bottom-top:%lx-%lx)\n",
current->comm, sp, stack_start, stack_start + THREAD_SIZE);
+#ifdef CONFIG_IRQSTACKS
+panic_check:
+#endif
if (sysctl_panic_on_stackoverflow)
panic("low stack detected by irq handler - check messages\n");
#endif
}
#ifdef CONFIG_IRQSTACKS
-DEFINE_PER_CPU(union irq_stack_union, irq_stack_union);
+DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = {
+ .lock = __RAW_SPIN_LOCK_UNLOCKED((irq_stack_union).lock)
+ };
static void execute_on_irq_stack(void *func, unsigned long param1)
{
- unsigned long *irq_stack_start;
+ union irq_stack_union *union_ptr;
unsigned long irq_stack;
- int cpu = smp_processor_id();
+ raw_spinlock_t *irq_stack_in_use;
- irq_stack_start = &per_cpu(irq_stack_union, cpu).stack[0];
- irq_stack = (unsigned long) irq_stack_start;
- irq_stack = ALIGN(irq_stack, 16); /* align for stack frame usage */
+ union_ptr = &per_cpu(irq_stack_union, smp_processor_id());
+ irq_stack = (unsigned long) &union_ptr->stack;
+ irq_stack = ALIGN(irq_stack + sizeof(irq_stack_union.lock),
+ 64); /* align for stack frame usage */
- BUG_ON(*irq_stack_start); /* report bug if we were called recursive. */
- *irq_stack_start = 1;
+ /* We may be called recursive. If we are already using the irq stack,
+ * just continue to use it. Use spinlocks to serialize
+ * the irq stack usage.
+ */
+ irq_stack_in_use = &union_ptr->lock;
+ if (!raw_spin_trylock(irq_stack_in_use)) {
+ void (*direct_call)(unsigned long p1) = func;
+
+ /* We are using the IRQ stack already.
+ * Do direct call on current stack. */
+ direct_call(param1);
+ return;
+ }
/* This is where we switch to the IRQ stack. */
call_on_stack(param1, func, irq_stack);
- *irq_stack_start = 0;
+ __inc_irq_stat(irq_stack_counter);
+
+ /* free up irq stack usage. */
+ do_raw_spin_unlock(irq_stack_in_use);
+}
+
+asmlinkage void do_softirq(void)
+{
+ __u32 pending;
+ unsigned long flags;
+
+ if (in_interrupt())
+ return;
+
+ local_irq_save(flags);
+
+ pending = local_softirq_pending();
+
+ if (pending)
+ execute_on_irq_stack(__do_softirq, 0);
+
+ local_irq_restore(flags);
}
#endif /* CONFIG_IRQSTACKS */
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index ce939ac8622b..1c965642068b 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -1069,7 +1069,7 @@ void flush_tlb_all(void)
{
int do_recycle;
- inc_irq_stat(irq_tlb_count);
+ __inc_irq_stat(irq_tlb_count);
do_recycle = 0;
spin_lock(&sid_lock);
if (dirty_space_ids > RECYCLE_THRESHOLD) {
@@ -1090,7 +1090,7 @@ void flush_tlb_all(void)
#else
void flush_tlb_all(void)
{
- inc_irq_stat(irq_tlb_count);
+ __inc_irq_stat(irq_tlb_count);
spin_lock(&sid_lock);
flush_tlb_all_local(NULL);
recycle_sids();
OpenPOWER on IntegriCloud