1 files changed, 199 insertions, 26 deletions

diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index cb450e1e79b..cfe056fe7f5 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -27,11 +27,11 @@
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 #include <linux/seq_file.h>
-#include <linux/spinlock.h>
 #include <linux/types.h>
 #include <asm/io.h>
 
 #include <asm/smp.h>
+#include <asm/ldcw.h>
 
 #undef PARISC_IRQ_CR16_COUNTS
 
@@ -113,16 +113,11 @@ int cpu_check_affinity(struct irq_data *d, const struct cpumask *dest)
 	int cpu_dest;
 
 	/* timer and ipi have to always be received on all CPUs */
-	if (CHECK_IRQ_PER_CPU(irq_to_desc(d->irq)->status)) {
-		/* Bad linux design decision.  The mask has already
-		 * been set; we must reset it. Will fix - tglx
-		 */
-		cpumask_setall(d->affinity);
+	if (irqd_is_per_cpu(d))
 		return -EINVAL;
-	}
 
 	/* whatever mask they set, we just allow one CPU */
-	cpu_dest = first_cpu(*dest);
+	cpu_dest = cpumask_first_and(dest, cpu_online_mask);
 
 	return cpu_dest;
 }
@@ -157,6 +152,49 @@ static struct irq_chip cpu_interrupt_type = {
 	.irq_retrigger	= NULL,
 };
 
+DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+#define irq_stats(x)		(&per_cpu(irq_stat, x))
+
+/*
+ * /proc/interrupts printing for arch specific interrupts
+ */
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+	int j;
+
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+	seq_printf(p, "%*s: ", prec, "STK");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->kernel_stack_usage);
+	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");
+# 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_puts(p, "  Rescheduling interrupts\n");
+#endif
+	seq_printf(p, "%*s: ", prec, "UAH");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_unaligned_count);
+	seq_puts(p, "  Unaligned access handler traps\n");
+	seq_printf(p, "%*s: ", prec, "FPA");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_fpassist_count);
+	seq_puts(p, "  Floating point assist traps\n");
+	seq_printf(p, "%*s: ", prec, "TLB");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
+	seq_puts(p, "  TLB shootdowns\n");
+	return 0;
+}
+
 int show_interrupts(struct seq_file *p, void *v)
 {
 	int i = *(loff_t *) v, j;
@@ -174,10 +212,11 @@ int show_interrupts(struct seq_file *p, void *v)
 	}
 
 	if (i < NR_IRQS) {
+		struct irq_desc *desc = irq_to_desc(i);
 		struct irqaction *action;
 
-		raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
-		action = irq_desc[i].action;
+		raw_spin_lock_irqsave(&desc->lock, flags);
+		action = desc->action;
 		if (!action)
 			goto skip;
 		seq_printf(p, "%3d: ", i);
@@ -188,7 +227,7 @@ int show_interrupts(struct seq_file *p, void *v)
 		seq_printf(p, "%10u ", kstat_irqs(i));
 #endif
 
-		seq_printf(p, " %14s", irq_desc[i].irq_data.chip->name);
+		seq_printf(p, " %14s", irq_desc_get_chip(desc)->name);
 #ifndef PARISC_IRQ_CR16_COUNTS
 		seq_printf(p, "  %s", action->name);
 
@@ -220,9 +259,12 @@ int show_interrupts(struct seq_file *p, void *v)
 
 		seq_putc(p, '\n');
  skip:
-		raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
+		raw_spin_unlock_irqrestore(&desc->lock, flags);
 	}
 
+	if (i == NR_IRQS)
+		arch_show_interrupts(p, 3);
+
 	return 0;
 }
 
@@ -238,15 +280,15 @@ int show_interrupts(struct seq_file *p, void *v)
 
 int cpu_claim_irq(unsigned int irq, struct irq_chip *type, void *data)
 {
-	if (irq_desc[irq].action)
+	if (irq_has_action(irq))
 		return -EBUSY;
-	if (get_irq_chip(irq) != &cpu_interrupt_type)
+	if (irq_get_chip(irq) != &cpu_interrupt_type)
 		return -EBUSY;
 
 	/* for iosapic interrupts */
 	if (type) {
-		set_irq_chip_and_handler(irq, type, handle_percpu_irq);
-		set_irq_chip_data(irq, data);
+		irq_set_chip_and_handler(irq, type, handle_percpu_irq);
+		irq_set_chip_data(irq, data);
 		__cpu_unmask_irq(irq);
 	}
 	return 0;
@@ -334,6 +376,131 @@ 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)];
+	volatile unsigned int slock[4];
+	volatile unsigned int lock[1];
+};
+
+DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = {
+		.slock = { 1,1,1,1 },
+	};
+#endif
+
+
+int sysctl_panic_on_stackoverflow = 1;
+
+static inline void stack_overflow_check(struct pt_regs *regs)
+{
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+	#define STACK_MARGIN	(256*6)
+
+	/* Our stack starts directly behind the thread_info struct. */
+	unsigned long stack_start = (unsigned long) current_thread_info();
+	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. */
+	if (regs->sr[7])
+		return;
+
+	/* calculate kernel stack usage */
+	stack_usage = sp - stack_start;
+#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;
+
+	if (likely(stack_usage < (THREAD_SIZE - STACK_MARGIN)))
+		return;
+
+	pr_emerg("stackcheck: %s will most likely overflow kernel stack "
+		 "(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
+/* 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;
+	volatile unsigned int *irq_stack_in_use;
+
+	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.slock),
+			 64); /* align for stack frame usage */
+
+	/* 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 = (volatile unsigned int *)__ldcw_align(union_ptr);
+	if (!__ldcw(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);
+
+	/* free up irq stack usage. */
+	*irq_stack_in_use = 1;
+}
+
+void do_softirq_own_stack(void)
+{
+	execute_on_irq_stack(__do_softirq, 0);
+}
+#endif /* CONFIG_IRQSTACKS */
+
 /* ONLY called from entry.S:intr_extint() */
 void do_cpu_irq_mask(struct pt_regs *regs)
 {
@@ -357,7 +524,7 @@ void do_cpu_irq_mask(struct pt_regs *regs)
 #ifdef CONFIG_SMP
 	desc = irq_to_desc(irq);
 	cpumask_copy(&dest, desc->irq_data.affinity);
-	if (CHECK_IRQ_PER_CPU(desc->status) &&
+	if (irqd_is_per_cpu(&desc->irq_data) &&
 	    !cpu_isset(smp_processor_id(), dest)) {
 		int cpu = first_cpu(dest);
 
@@ -368,7 +535,13 @@ void do_cpu_irq_mask(struct pt_regs *regs)
 		goto set_out;
 	}
 #endif
+	stack_overflow_check(regs);
+
+#ifdef CONFIG_IRQSTACKS
+	execute_on_irq_stack(&generic_handle_irq, irq);
+#else
 	generic_handle_irq(irq);
+#endif /* CONFIG_IRQSTACKS */
 
  out:
 	irq_exit();
@@ -383,14 +556,14 @@ void do_cpu_irq_mask(struct pt_regs *regs)
 static struct irqaction timer_action = {
 	.handler = timer_interrupt,
 	.name = "timer",
-	.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL,
+	.flags = IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL,
 };
 
 #ifdef CONFIG_SMP
 static struct irqaction ipi_action = {
 	.handler = ipi_interrupt,
 	.name = "IPI",
-	.flags = IRQF_DISABLED | IRQF_PERCPU,
+	.flags = IRQF_PERCPU,
 };
 #endif
 
@@ -398,14 +571,14 @@ static void claim_cpu_irqs(void)
 {
 	int i;
 	for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
-		set_irq_chip_and_handler(i, &cpu_interrupt_type,
+		irq_set_chip_and_handler(i, &cpu_interrupt_type,
 					 handle_percpu_irq);
 	}
 
-	set_irq_handler(TIMER_IRQ, handle_percpu_irq);
+	irq_set_handler(TIMER_IRQ, handle_percpu_irq);
 	setup_irq(TIMER_IRQ, &timer_action);
 #ifdef CONFIG_SMP
-	set_irq_handler(IPI_IRQ, handle_percpu_irq);
+	irq_set_handler(IPI_IRQ, handle_percpu_irq);
 	setup_irq(IPI_IRQ, &ipi_action);
 #endif
 }
@@ -414,14 +587,14 @@ void __init init_IRQ(void)
 {
 	local_irq_disable();	/* PARANOID - should already be disabled */
 	mtctl(~0UL, 23);	/* EIRR : clear all pending external intr */
-	claim_cpu_irqs();
 #ifdef CONFIG_SMP
-	if (!cpu_eiem)
+	if (!cpu_eiem) {
+		claim_cpu_irqs();
 		cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
+	}
 #else
+	claim_cpu_irqs();
 	cpu_eiem = EIEM_MASK(TIMER_IRQ);
 #endif
         set_eiem(cpu_eiem);	/* EIEM : enable all external intr */
-
 }
-