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-rw-r--r--arch/mips/kernel/irq_cpu.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/arch/mips/kernel/irq_cpu.c b/arch/mips/kernel/irq_cpu.c
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+++ b/arch/mips/kernel/irq_cpu.c
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+/*
+ * 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;
+}