[PATCH v3 11/31] arm64: IRQ handling

From: Catalin Marinas
Date: Fri Sep 07 2012 - 12:34:33 EST


From: Marc Zyngier <marc.zyngier@xxxxxxx>

This patch adds the support for IRQ handling. The actual interrupt
controller will be part of a separate patch (going into
drivers/irqchip/).

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Acked-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
arch/arm64/include/asm/hardirq.h | 47 +++++++++++++++++++
arch/arm64/include/asm/irq.h | 8 +++
arch/arm64/include/asm/irqflags.h | 91 +++++++++++++++++++++++++++++++++++++
arch/arm64/kernel/irq.c | 84 ++++++++++++++++++++++++++++++++++
4 files changed, 230 insertions(+), 0 deletions(-)
create mode 100644 arch/arm64/include/asm/hardirq.h
create mode 100644 arch/arm64/include/asm/irq.h
create mode 100644 arch/arm64/include/asm/irqflags.h
create mode 100644 arch/arm64/kernel/irq.c

diff --git a/arch/arm64/include/asm/hardirq.h b/arch/arm64/include/asm/hardirq.h
new file mode 100644
index 0000000..c6c9514
--- /dev/null
+++ b/arch/arm64/include/asm/hardirq.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_HARDIRQ_H
+#define __ASM_HARDIRQ_H
+
+#include <linux/cache.h>
+#include <linux/threads.h>
+#include <asm/irq.h>
+
+typedef struct {
+ unsigned int __softirq_pending;
+} ____cacheline_aligned irq_cpustat_t;
+
+#include <linux/irq_cpustat.h> /* Standard mappings for irq_cpustat_t above */
+
+#define __inc_irq_stat(cpu, member) __IRQ_STAT(cpu, member)++
+#define __get_irq_stat(cpu, member) __IRQ_STAT(cpu, member)
+
+#ifdef CONFIG_SMP
+u64 smp_irq_stat_cpu(unsigned int cpu);
+#define arch_irq_stat_cpu smp_irq_stat_cpu
+#endif
+
+#define __ARCH_IRQ_EXIT_IRQS_DISABLED 1
+
+static inline void ack_bad_irq(unsigned int irq)
+{
+ extern unsigned long irq_err_count;
+ irq_err_count++;
+}
+
+extern void handle_IRQ(unsigned int, struct pt_regs *);
+
+#endif /* __ASM_HARDIRQ_H */
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
new file mode 100644
index 0000000..a4e1cad
--- /dev/null
+++ b/arch/arm64/include/asm/irq.h
@@ -0,0 +1,8 @@
+#ifndef __ASM_IRQ_H
+#define __ASM_IRQ_H
+
+#include <asm-generic/irq.h>
+
+extern void (*handle_arch_irq)(struct pt_regs *);
+
+#endif
diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h
new file mode 100644
index 0000000..aa11943
--- /dev/null
+++ b/arch/arm64/include/asm/irqflags.h
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_IRQFLAGS_H
+#define __ASM_IRQFLAGS_H
+
+#ifdef __KERNEL__
+
+#include <asm/ptrace.h>
+
+/*
+ * CPU interrupt mask handling.
+ */
+static inline unsigned long arch_local_irq_save(void)
+{
+ unsigned long flags;
+ asm volatile(
+ "mrs %0, daif // arch_local_irq_save\n"
+ "msr daifset, #2"
+ : "=r" (flags)
+ :
+ : "memory");
+ return flags;
+}
+
+static inline void arch_local_irq_enable(void)
+{
+ asm volatile(
+ "msr daifclr, #2 // arch_local_irq_enable"
+ :
+ :
+ : "memory");
+}
+
+static inline void arch_local_irq_disable(void)
+{
+ asm volatile(
+ "msr daifset, #2 // arch_local_irq_disable"
+ :
+ :
+ : "memory");
+}
+
+#define local_fiq_enable() asm("msr daifclr, #1" : : : "memory")
+#define local_fiq_disable() asm("msr daifset, #1" : : : "memory")
+
+/*
+ * Save the current interrupt enable state.
+ */
+static inline unsigned long arch_local_save_flags(void)
+{
+ unsigned long flags;
+ asm volatile(
+ "mrs %0, daif // arch_local_save_flags"
+ : "=r" (flags)
+ :
+ : "memory");
+ return flags;
+}
+
+/*
+ * restore saved IRQ state
+ */
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+ asm volatile(
+ "msr daif, %0 // arch_local_irq_restore"
+ :
+ : "r" (flags)
+ : "memory");
+}
+
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+ return flags & PSR_I_BIT;
+}
+
+#endif
+#endif
diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
new file mode 100644
index 0000000..0373c66
--- /dev/null
+++ b/arch/arm64/kernel/irq.c
@@ -0,0 +1,84 @@
+/*
+ * Based on arch/arm/kernel/irq.c
+ *
+ * Copyright (C) 1992 Linus Torvalds
+ * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
+ * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
+ * Dynamic Tick Timer written by Tony Lindgren <tony@xxxxxxxxxxx> and
+ * Tuukka Tikkanen <tuukka.tikkanen@xxxxxxxxxxxxxx>.
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel_stat.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/of_irq.h>
+#include <linux/seq_file.h>
+#include <linux/ratelimit.h>
+
+unsigned long irq_err_count;
+
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+#ifdef CONFIG_SMP
+ show_ipi_list(p, prec);
+#endif
+ seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
+ return 0;
+}
+
+/*
+ * handle_IRQ handles all hardware IRQ's. Decoded IRQs should
+ * not come via this function. Instead, they should provide their
+ * own 'handler'. Used by platform code implementing C-based 1st
+ * level decoding.
+ */
+void handle_IRQ(unsigned int irq, struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+
+ irq_enter();
+
+ /*
+ * Some hardware gives randomly wrong interrupts. Rather
+ * than crashing, do something sensible.
+ */
+ if (unlikely(irq >= nr_irqs)) {
+ pr_warn_ratelimited("Bad IRQ%u\n", irq);
+ ack_bad_irq(irq);
+ } else {
+ generic_handle_irq(irq);
+ }
+
+ irq_exit();
+ set_irq_regs(old_regs);
+}
+
+/*
+ * Interrupt controllers supported by the kernel.
+ */
+static const struct of_device_id intctrl_of_match[] __initconst = {
+ /* IRQ controllers { .compatible, .data } info to go here */
+ {}
+};
+
+void __init init_IRQ(void)
+{
+ of_irq_init(intctrl_of_match);
+
+ if (!handle_arch_irq)
+ panic("No interrupt controller found.");
+}

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