1 files changed, 355 insertions, 0 deletions
diff --git a/arch/mn10300/kernel/irq.c b/arch/mn10300/kernel/irq.c
new file mode 100644
index 000000000..6ab3b73ef
--- /dev/null
+++ b/arch/mn10300/kernel/irq.c
@@ -0,0 +1,355 @@
+/* MN10300 Arch-specific interrupt handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/seq_file.h>
+#include <linux/cpumask.h>
+#include <asm/setup.h>
+#include <asm/serial-regs.h>
+
+unsigned long __mn10300_irq_enabled_epsw[NR_CPUS] __cacheline_aligned_in_smp = {
+	[0 ... NR_CPUS - 1] = EPSW_IE | EPSW_IM_7
+};
+EXPORT_SYMBOL(__mn10300_irq_enabled_epsw);
+
+#ifdef CONFIG_SMP
+static char irq_affinity_online[NR_IRQS] = {
+	[0 ... NR_IRQS - 1] = 0
+};
+
+#define NR_IRQ_WORDS	((NR_IRQS + 31) / 32)
+static unsigned long irq_affinity_request[NR_IRQ_WORDS] = {
+	[0 ... NR_IRQ_WORDS - 1] = 0
+};
+#endif  /* CONFIG_SMP */
+
+atomic_t irq_err_count;
+
+/*
+ * MN10300 interrupt controller operations
+ */
+static void mn10300_cpupic_ack(struct irq_data *d)
+{
+	unsigned int irq = d->irq;
+	unsigned long flags;
+	u16 tmp;
+
+	flags = arch_local_cli_save();
+	GxICR_u8(irq) = GxICR_DETECT;
+	tmp = GxICR(irq);
+	arch_local_irq_restore(flags);
+}
+
+static void __mask_and_set_icr(unsigned int irq,
+			       unsigned int mask, unsigned int set)
+{
+	unsigned long flags;
+	u16 tmp;
+
+	flags = arch_local_cli_save();
+	tmp = GxICR(irq);
+	GxICR(irq) = (tmp & mask) | set;
+	tmp = GxICR(irq);
+	arch_local_irq_restore(flags);
+}
+
+static void mn10300_cpupic_mask(struct irq_data *d)
+{
+	__mask_and_set_icr(d->irq, GxICR_LEVEL, 0);
+}
+
+static void mn10300_cpupic_mask_ack(struct irq_data *d)
+{
+	unsigned int irq = d->irq;
+#ifdef CONFIG_SMP
+	unsigned long flags;
+	u16 tmp;
+
+	flags = arch_local_cli_save();
+
+	if (!test_and_clear_bit(irq, irq_affinity_request)) {
+		tmp = GxICR(irq);
+		GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_DETECT;
+		tmp = GxICR(irq);
+	} else {
+		u16 tmp2;
+		tmp = GxICR(irq);
+		GxICR(irq) = (tmp & GxICR_LEVEL);
+		tmp2 = GxICR(irq);
+
+		irq_affinity_online[irq] =
+			cpumask_any_and(d->affinity, cpu_online_mask);
+		CROSS_GxICR(irq, irq_affinity_online[irq]) =
+			(tmp & (GxICR_LEVEL | GxICR_ENABLE)) | GxICR_DETECT;
+		tmp = CROSS_GxICR(irq, irq_affinity_online[irq]);
+	}
+
+	arch_local_irq_restore(flags);
+#else  /* CONFIG_SMP */
+	__mask_and_set_icr(irq, GxICR_LEVEL, GxICR_DETECT);
+#endif /* CONFIG_SMP */
+}
+
+static void mn10300_cpupic_unmask(struct irq_data *d)
+{
+	__mask_and_set_icr(d->irq, GxICR_LEVEL, GxICR_ENABLE);
+}
+
+static void mn10300_cpupic_unmask_clear(struct irq_data *d)
+{
+	unsigned int irq = d->irq;
+	/* the MN10300 PIC latches its interrupt request bit, even after the
+	 * device has ceased to assert its interrupt line and the interrupt
+	 * channel has been disabled in the PIC, so for level-triggered
+	 * interrupts we need to clear the request bit when we re-enable */
+#ifdef CONFIG_SMP
+	unsigned long flags;
+	u16 tmp;
+
+	flags = arch_local_cli_save();
+
+	if (!test_and_clear_bit(irq, irq_affinity_request)) {
+		tmp = GxICR(irq);
+		GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
+		tmp = GxICR(irq);
+	} else {
+		tmp = GxICR(irq);
+
+		irq_affinity_online[irq] = cpumask_any_and(d->affinity,
+							   cpu_online_mask);
+		CROSS_GxICR(irq, irq_affinity_online[irq]) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
+		tmp = CROSS_GxICR(irq, irq_affinity_online[irq]);
+	}
+
+	arch_local_irq_restore(flags);
+#else  /* CONFIG_SMP */
+	__mask_and_set_icr(irq, GxICR_LEVEL, GxICR_ENABLE | GxICR_DETECT);
+#endif /* CONFIG_SMP */
+}
+
+#ifdef CONFIG_SMP
+static int
+mn10300_cpupic_setaffinity(struct irq_data *d, const struct cpumask *mask,
+			   bool force)
+{
+	unsigned long flags;
+
+	flags = arch_local_cli_save();
+	set_bit(d->irq, irq_affinity_request);
+	arch_local_irq_restore(flags);
+	return 0;
+}
+#endif /* CONFIG_SMP */
+
+/*
+ * MN10300 PIC level-triggered IRQ handling.
+ *
+ * The PIC has no 'ACK' function per se.  It is possible to clear individual
+ * channel latches, but each latch relatches whether or not the channel is
+ * masked, so we need to clear the latch when we unmask the channel.
+ *
+ * Also for this reason, we don't supply an ack() op (it's unused anyway if
+ * mask_ack() is provided), and mask_ack() just masks.
+ */
+static struct irq_chip mn10300_cpu_pic_level = {
+	.name			= "cpu_l",
+	.irq_disable		= mn10300_cpupic_mask,
+	.irq_enable		= mn10300_cpupic_unmask_clear,
+	.irq_ack		= NULL,
+	.irq_mask		= mn10300_cpupic_mask,
+	.irq_mask_ack		= mn10300_cpupic_mask,
+	.irq_unmask		= mn10300_cpupic_unmask_clear,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	= mn10300_cpupic_setaffinity,
+#endif
+};
+
+/*
+ * MN10300 PIC edge-triggered IRQ handling.
+ *
+ * We use the latch clearing function of the PIC as the 'ACK' function.
+ */
+static struct irq_chip mn10300_cpu_pic_edge = {
+	.name			= "cpu_e",
+	.irq_disable		= mn10300_cpupic_mask,
+	.irq_enable		= mn10300_cpupic_unmask,
+	.irq_ack		= mn10300_cpupic_ack,
+	.irq_mask		= mn10300_cpupic_mask,
+	.irq_mask_ack		= mn10300_cpupic_mask_ack,
+	.irq_unmask		= mn10300_cpupic_unmask,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	= mn10300_cpupic_setaffinity,
+#endif
+};
+
+/*
+ * 'what should we do if we get a hw irq event on an illegal vector'.
+ * each architecture has to answer this themselves.
+ */
+void ack_bad_irq(int irq)
+{
+	printk(KERN_WARNING "unexpected IRQ trap at vector %02x\n", irq);
+}
+
+/*
+ * change the level at which an IRQ executes
+ * - must not be called whilst interrupts are being processed!
+ */
+void set_intr_level(int irq, u16 level)
+{
+	BUG_ON(in_interrupt());
+
+	__mask_and_set_icr(irq, GxICR_ENABLE, level);
+}
+
+/*
+ * mark an interrupt to be ACK'd after interrupt handlers have been run rather
+ * than before
+ */
+void mn10300_set_lateack_irq_type(int irq)
+{
+	irq_set_chip_and_handler(irq, &mn10300_cpu_pic_level,
+				 handle_level_irq);
+}
+
+/*
+ * initialise the interrupt system
+ */
+void __init init_IRQ(void)
+{
+	int irq;
+
+	for (irq = 0; irq < NR_IRQS; irq++)
+		if (irq_get_chip(irq) == &no_irq_chip)
+			/* due to the PIC latching interrupt requests, even
+			 * when the IRQ is disabled, IRQ_PENDING is superfluous
+			 * and we can use handle_level_irq() for edge-triggered
+			 * interrupts */
+			irq_set_chip_and_handler(irq, &mn10300_cpu_pic_edge,
+						 handle_level_irq);
+
+	unit_init_IRQ();
+}
+
+/*
+ * handle normal device IRQs
+ */
+asmlinkage void do_IRQ(void)
+{
+	unsigned long sp, epsw, irq_disabled_epsw, old_irq_enabled_epsw;
+	unsigned int cpu_id = smp_processor_id();
+	int irq;
+
+	sp = current_stack_pointer();
+	BUG_ON(sp - (sp & ~(THREAD_SIZE - 1)) < STACK_WARN);
+
+	/* make sure local_irq_enable() doesn't muck up the interrupt priority
+	 * setting in EPSW */
+	old_irq_enabled_epsw = __mn10300_irq_enabled_epsw[cpu_id];
+	local_save_flags(epsw);
+	__mn10300_irq_enabled_epsw[cpu_id] = EPSW_IE | (EPSW_IM & epsw);
+	irq_disabled_epsw = EPSW_IE | MN10300_CLI_LEVEL;
+
+#ifdef CONFIG_MN10300_WD_TIMER
+	__IRQ_STAT(cpu_id, __irq_count)++;
+#endif
+
+	irq_enter();
+
+	for (;;) {
+		/* ask the interrupt controller for the next IRQ to process
+		 * - the result we get depends on EPSW.IM
+		 */
+		irq = IAGR & IAGR_GN;
+		if (!irq)
+			break;
+
+		local_irq_restore(irq_disabled_epsw);
+
+		generic_handle_irq(irq >> 2);
+
+		/* restore IRQ controls for IAGR access */
+		local_irq_restore(epsw);
+	}
+
+	__mn10300_irq_enabled_epsw[cpu_id] = old_irq_enabled_epsw;
+
+	irq_exit();
+}
+
+/*
+ * Display interrupt management information through /proc/interrupts
+ */
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+#ifdef CONFIG_MN10300_WD_TIMER
+	int j;
+
+	seq_printf(p, "%*s: ", prec, "NMI");
+	for (j = 0; j < NR_CPUS; j++)
+		if (cpu_online(j))
+			seq_printf(p, "%10u ", nmi_count(j));
+	seq_putc(p, '\n');
+#endif
+
+	seq_printf(p, "%*s: ", prec, "ERR");
+	seq_printf(p, "%10u\n", atomic_read(&irq_err_count));
+	return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void migrate_irqs(void)
+{
+	int irq;
+	unsigned int self, new;
+	unsigned long flags;
+
+	self = smp_processor_id();
+	for (irq = 0; irq < NR_IRQS; irq++) {
+		struct irq_data *data = irq_get_irq_data(irq);
+
+		if (irqd_is_per_cpu(data))
+			continue;
+
+		if (cpumask_test_cpu(self, &data->affinity) &&
+		    !cpumask_intersects(&irq_affinity[irq], cpu_online_mask)) {
+			int cpu_id;
+			cpu_id = cpumask_first(cpu_online_mask);
+			cpumask_set_cpu(cpu_id, &data->affinity);
+		}
+		/* We need to operate irq_affinity_online atomically. */
+		arch_local_cli_save(flags);
+		if (irq_affinity_online[irq] == self) {
+			u16 x, tmp;
+
+			x = GxICR(irq);
+			GxICR(irq) = x & GxICR_LEVEL;
+			tmp = GxICR(irq);
+
+			new = cpumask_any_and(&data->affinity,
+					      cpu_online_mask);
+			irq_affinity_online[irq] = new;
+
+			CROSS_GxICR(irq, new) =
+				(x & GxICR_LEVEL) | GxICR_DETECT;
+			tmp = CROSS_GxICR(irq, new);
+
+			x &= GxICR_LEVEL | GxICR_ENABLE;
+			if (GxICR(irq) & GxICR_REQUEST)
+				x |= GxICR_REQUEST | GxICR_DETECT;
+			CROSS_GxICR(irq, new) = x;
+			tmp = CROSS_GxICR(irq, new);
+		}
+		arch_local_irq_restore(flags);
+	}
+}
+#endif /* CONFIG_HOTPLUG_CPU */