LoongArch: Add exception/interrupt handling

Add the exception and interrupt handling machanism for basic LoongArch
support.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

1 files changed, 78 insertions, 0 deletions

diff --git a/arch/loongarch/include/asm/irqflags.h b/arch/loongarch/include/asm/irqflags.h
new file mode 100644
index 000000000000..52121cd791fe
--- /dev/null
+++ b/arch/loongarch/include/asm/irqflags.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_IRQFLAGS_H
+#define _ASM_IRQFLAGS_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/compiler.h>
+#include <linux/stringify.h>
+#include <asm/compiler.h>
+#include <asm/loongarch.h>
+
+static inline void arch_local_irq_enable(void)
+{
+	u32 flags = CSR_CRMD_IE;
+	__asm__ __volatile__(
+		"csrxchg %[val], %[mask], %[reg]\n\t"
+		: [val] "+r" (flags)
+		: [mask] "r" (CSR_CRMD_IE), [reg] "i" (LOONGARCH_CSR_CRMD)
+		: "memory");
+}
+
+static inline void arch_local_irq_disable(void)
+{
+	u32 flags = 0;
+	__asm__ __volatile__(
+		"csrxchg %[val], %[mask], %[reg]\n\t"
+		: [val] "+r" (flags)
+		: [mask] "r" (CSR_CRMD_IE), [reg] "i" (LOONGARCH_CSR_CRMD)
+		: "memory");
+}
+
+static inline unsigned long arch_local_irq_save(void)
+{
+	u32 flags = 0;
+	__asm__ __volatile__(
+		"csrxchg %[val], %[mask], %[reg]\n\t"
+		: [val] "+r" (flags)
+		: [mask] "r" (CSR_CRMD_IE), [reg] "i" (LOONGARCH_CSR_CRMD)
+		: "memory");
+	return flags;
+}
+
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+	__asm__ __volatile__(
+		"csrxchg %[val], %[mask], %[reg]\n\t"
+		: [val] "+r" (flags)
+		: [mask] "r" (CSR_CRMD_IE), [reg] "i" (LOONGARCH_CSR_CRMD)
+		: "memory");
+}
+
+static inline unsigned long arch_local_save_flags(void)
+{
+	u32 flags;
+	__asm__ __volatile__(
+		"csrrd %[val], %[reg]\n\t"
+		: [val] "=r" (flags)
+		: [reg] "i" (LOONGARCH_CSR_CRMD)
+		: "memory");
+	return flags;
+}
+
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+	return !(flags & CSR_CRMD_IE);
+}
+
+static inline int arch_irqs_disabled(void)
+{
+	return arch_irqs_disabled_flags(arch_local_save_flags());
+}
+
+#endif /* #ifndef __ASSEMBLY__ */
+
+#endif /* _ASM_IRQFLAGS_H */