MIPS/IRQCHIP: Move irq_chip from arch/mips to drivers/irqchip.

While at it, rename it because in drivers/irqchip no longer every CPU is
a MIPS.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 169 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c
new file mode 100644
index 000000000000..6eb7a3f515fc
--- /dev/null
+++ b/drivers/irqchip/irq-mips-cpu.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright 2001 MontaVista Software Inc.
+ * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
+ *
+ * Copyright (C) 2001 Ralf Baechle
+ * Copyright (C) 2005  MIPS Technologies, Inc.	All rights reserved.
+ *	Author: Maciej W. Rozycki <macro@mips.com>
+ *
+ * This file define the irq handler for MIPS CPU interrupts.
+ *
+ * This program is free software; you can redistribute	it and/or modify it
+ * under  the terms of	the GNU General	 Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+/*
+ * Almost all MIPS CPUs define 8 interrupt sources.  They are typically
+ * level triggered (i.e., cannot be cleared from CPU; must be cleared from
+ * device).  The first two are software interrupts which we don't really
+ * use or support.  The last one is usually the CPU timer interrupt if
+ * counter register is present or, for CPUs with an external FPU, by
+ * convention it's the FPU exception interrupt.
+ *
+ * Don't even think about using this on SMP.  You have been warned.
+ *
+ * This file exports one global function:
+ *	void mips_cpu_irq_init(void);
+ */
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+
+#include <asm/irq_cpu.h>
+#include <asm/mipsregs.h>
+#include <asm/mipsmtregs.h>
+#include <asm/setup.h>
+
+static inline void unmask_mips_irq(struct irq_data *d)
+{
+	set_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
+	irq_enable_hazard();
+}
+
+static inline void mask_mips_irq(struct irq_data *d)
+{
+	clear_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
+	irq_disable_hazard();
+}
+
+static struct irq_chip mips_cpu_irq_controller = {
+	.name		= "MIPS",
+	.irq_ack	= mask_mips_irq,
+	.irq_mask	= mask_mips_irq,
+	.irq_mask_ack	= mask_mips_irq,
+	.irq_unmask	= unmask_mips_irq,
+	.irq_eoi	= unmask_mips_irq,
+	.irq_disable	= mask_mips_irq,
+	.irq_enable	= unmask_mips_irq,
+};
+
+/*
+ * Basically the same as above but taking care of all the MT stuff
+ */
+
+static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d)
+{
+	unsigned int vpflags = dvpe();
+
+	clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
+	evpe(vpflags);
+	unmask_mips_irq(d);
+	return 0;
+}
+
+/*
+ * While we ack the interrupt interrupts are disabled and thus we don't need
+ * to deal with concurrency issues.  Same for mips_cpu_irq_end.
+ */
+static void mips_mt_cpu_irq_ack(struct irq_data *d)
+{
+	unsigned int vpflags = dvpe();
+	clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
+	evpe(vpflags);
+	mask_mips_irq(d);
+}
+
+static struct irq_chip mips_mt_cpu_irq_controller = {
+	.name		= "MIPS",
+	.irq_startup	= mips_mt_cpu_irq_startup,
+	.irq_ack	= mips_mt_cpu_irq_ack,
+	.irq_mask	= mask_mips_irq,
+	.irq_mask_ack	= mips_mt_cpu_irq_ack,
+	.irq_unmask	= unmask_mips_irq,
+	.irq_eoi	= unmask_mips_irq,
+	.irq_disable	= mask_mips_irq,
+	.irq_enable	= unmask_mips_irq,
+};
+
+asmlinkage void __weak plat_irq_dispatch(void)
+{
+	unsigned long pending = read_c0_cause() & read_c0_status() & ST0_IM;
+	int irq;
+
+	if (!pending) {
+		spurious_interrupt();
+		return;
+	}
+
+	pending >>= CAUSEB_IP;
+	while (pending) {
+		irq = fls(pending) - 1;
+		do_IRQ(MIPS_CPU_IRQ_BASE + irq);
+		pending &= ~BIT(irq);
+	}
+}
+
+static int mips_cpu_intc_map(struct irq_domain *d, unsigned int irq,
+			     irq_hw_number_t hw)
+{
+	static struct irq_chip *chip;
+
+	if (hw < 2 && cpu_has_mipsmt) {
+		/* Software interrupts are used for MT/CMT IPI */
+		chip = &mips_mt_cpu_irq_controller;
+	} else {
+		chip = &mips_cpu_irq_controller;
+	}
+
+	if (cpu_has_vint)
+		set_vi_handler(hw, plat_irq_dispatch);
+
+	irq_set_chip_and_handler(irq, chip, handle_percpu_irq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops mips_cpu_intc_irq_domain_ops = {
+	.map = mips_cpu_intc_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+static void __init __mips_cpu_irq_init(struct device_node *of_node)
+{
+	struct irq_domain *domain;
+
+	/* Mask interrupts. */
+	clear_c0_status(ST0_IM);
+	clear_c0_cause(CAUSEF_IP);
+
+	domain = irq_domain_add_legacy(of_node, 8, MIPS_CPU_IRQ_BASE, 0,
+				       &mips_cpu_intc_irq_domain_ops, NULL);
+	if (!domain)
+		panic("Failed to add irqdomain for MIPS CPU");
+}
+
+void __init mips_cpu_irq_init(void)
+{
+	__mips_cpu_irq_init(NULL);
+}
+
+int __init mips_cpu_irq_of_init(struct device_node *of_node,
+				struct device_node *parent)
+{
+	__mips_cpu_irq_init(of_node);
+	return 0;
+}