arm64: IRQ handling

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@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

3 files changed, 146 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/hardirq.h b/arch/arm64/include/asm/hardirq.h
new file mode 100644
index 00000000000..c6c95145c17
--- /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 00000000000..a4e1cad3202
--- /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 00000000000..aa11943b850
--- /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