[PATCH V15 12/24] LoongArch: Add exception/interrupt handling

From: Huacai Chen
Date: Fri Jun 03 2022 - 03:25:43 EST

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

Reviewed-by: WANG Xuerui <git@xxxxxxxxxx>
Reviewed-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
arch/loongarch/include/asm/branch.h | 21 +
arch/loongarch/include/asm/bug.h | 23 +
arch/loongarch/include/asm/entry-common.h | 13 +
arch/loongarch/include/asm/hardirq.h | 24 +
arch/loongarch/include/asm/hw_irq.h | 17 +
arch/loongarch/include/asm/irq.h | 130 ++++
arch/loongarch/include/asm/irq_regs.h | 27 +
arch/loongarch/include/asm/irqflags.h | 78 +++
arch/loongarch/include/asm/kdebug.h | 23 +
arch/loongarch/include/asm/stackframe.h | 212 +++++++
arch/loongarch/include/asm/stacktrace.h | 74 +++
arch/loongarch/include/uapi/asm/break.h | 23 +
arch/loongarch/kernel/access-helper.h | 13 +
arch/loongarch/kernel/genex.S | 95 +++
arch/loongarch/kernel/irq.c | 77 +++
arch/loongarch/kernel/traps.c | 725 ++++++++++++++++++++++
16 files changed, 1575 insertions(+)
create mode 100644 arch/loongarch/include/asm/branch.h
create mode 100644 arch/loongarch/include/asm/bug.h
create mode 100644 arch/loongarch/include/asm/entry-common.h
create mode 100644 arch/loongarch/include/asm/hardirq.h
create mode 100644 arch/loongarch/include/asm/hw_irq.h
create mode 100644 arch/loongarch/include/asm/irq.h
create mode 100644 arch/loongarch/include/asm/irq_regs.h
create mode 100644 arch/loongarch/include/asm/irqflags.h
create mode 100644 arch/loongarch/include/asm/kdebug.h
create mode 100644 arch/loongarch/include/asm/stackframe.h
create mode 100644 arch/loongarch/include/asm/stacktrace.h
create mode 100644 arch/loongarch/include/uapi/asm/break.h
create mode 100644 arch/loongarch/kernel/access-helper.h
create mode 100644 arch/loongarch/kernel/genex.S
create mode 100644 arch/loongarch/kernel/irq.c
create mode 100644 arch/loongarch/kernel/traps.c

diff --git a/arch/loongarch/include/asm/branch.h b/arch/loongarch/include/asm/branch.h
new file mode 100644
index 000000000000..3f33c89f35b4
--- /dev/null
+++ b/arch/loongarch/include/asm/branch.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_BRANCH_H
+#define _ASM_BRANCH_H
+
+#include <asm/ptrace.h>
+
+static inline unsigned long exception_era(struct pt_regs *regs)
+{
+ return regs->csr_era;
+}
+
+static inline int compute_return_era(struct pt_regs *regs)
+{
+ regs->csr_era += 4;
+ return 0;
+}
+
+#endif /* _ASM_BRANCH_H */
diff --git a/arch/loongarch/include/asm/bug.h b/arch/loongarch/include/asm/bug.h
new file mode 100644
index 000000000000..bda49108a76d
--- /dev/null
+++ b/arch/loongarch/include/asm/bug.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_BUG_H
+#define __ASM_BUG_H
+
+#include <linux/compiler.h>
+
+#ifdef CONFIG_BUG
+
+#include <asm/break.h>
+
+static inline void __noreturn BUG(void)
+{
+ __asm__ __volatile__("break %0" : : "i" (BRK_BUG));
+ unreachable();
+}
+
+#define HAVE_ARCH_BUG
+
+#endif
+
+#include <asm-generic/bug.h>
+
+#endif /* __ASM_BUG_H */
diff --git a/arch/loongarch/include/asm/entry-common.h b/arch/loongarch/include/asm/entry-common.h
new file mode 100644
index 000000000000..0fe2a098ded9
--- /dev/null
+++ b/arch/loongarch/include/asm/entry-common.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARCH_LOONGARCH_ENTRY_COMMON_H
+#define ARCH_LOONGARCH_ENTRY_COMMON_H
+
+#include <linux/sched.h>
+#include <linux/processor.h>
+
+static inline bool on_thread_stack(void)
+{
+ return !(((unsigned long)(current->stack) ^ current_stack_pointer) & ~(THREAD_SIZE - 1));
+}
+
+#endif
diff --git a/arch/loongarch/include/asm/hardirq.h b/arch/loongarch/include/asm/hardirq.h
new file mode 100644
index 000000000000..d32f83938880
--- /dev/null
+++ b/arch/loongarch/include/asm/hardirq.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_HARDIRQ_H
+#define _ASM_HARDIRQ_H
+
+#include <linux/cache.h>
+#include <linux/threads.h>
+#include <linux/irq.h>
+
+extern void ack_bad_irq(unsigned int irq);
+#define ack_bad_irq ack_bad_irq
+
+#define NR_IPI 2
+
+typedef struct {
+ unsigned int ipi_irqs[NR_IPI];
+ unsigned int __softirq_pending;
+} ____cacheline_aligned irq_cpustat_t;
+
+DECLARE_PER_CPU_ALIGNED(irq_cpustat_t, irq_stat);
+
+#endif /* _ASM_HARDIRQ_H */
diff --git a/arch/loongarch/include/asm/hw_irq.h b/arch/loongarch/include/asm/hw_irq.h
new file mode 100644
index 000000000000..af4f4e8fbd85
--- /dev/null
+++ b/arch/loongarch/include/asm/hw_irq.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_HW_IRQ_H
+#define __ASM_HW_IRQ_H
+
+#include <linux/atomic.h>
+
+extern atomic_t irq_err_count;
+
+/*
+ * interrupt-retrigger: NOP for now. This may not be appropriate for all
+ * machines, we'll see ...
+ */
+
+#endif /* __ASM_HW_IRQ_H */
diff --git a/arch/loongarch/include/asm/irq.h b/arch/loongarch/include/asm/irq.h
new file mode 100644
index 000000000000..f3f1baf7027c
--- /dev/null
+++ b/arch/loongarch/include/asm/irq.h
@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_IRQ_H
+#define _ASM_IRQ_H
+
+#include <linux/irqdomain.h>
+#include <linux/irqreturn.h>
+
+#define IRQ_STACK_SIZE THREAD_SIZE
+#define IRQ_STACK_START (IRQ_STACK_SIZE - 16)
+
+DECLARE_PER_CPU(unsigned long, irq_stack);
+
+/*
+ * The highest address on the IRQ stack contains a dummy frame which is
+ * structured as follows:
+ *
+ * top ------------
+ * | task sp | <- irq_stack[cpu] + IRQ_STACK_START
+ * ------------
+ * | | <- First frame of IRQ context
+ * ------------
+ *
+ * task sp holds a copy of the task stack pointer where the struct pt_regs
+ * from exception entry can be found.
+ */
+
+static inline bool on_irq_stack(int cpu, unsigned long sp)
+{
+ unsigned long low = per_cpu(irq_stack, cpu);
+ unsigned long high = low + IRQ_STACK_SIZE;
+
+ return (low <= sp && sp <= high);
+}
+
+int get_ipi_irq(void);
+int get_pmc_irq(void);
+int get_timer_irq(void);
+void spurious_interrupt(void);
+
+#define NR_IRQS_LEGACY 16
+
+#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
+void arch_trigger_cpumask_backtrace(const struct cpumask *mask, bool exclude_self);
+
+#define MAX_IO_PICS 2
+#define NR_IRQS (64 + (256 * MAX_IO_PICS))
+
+#define CORES_PER_EIO_NODE 4
+
+#define LOONGSON_CPU_UART0_VEC 10 /* CPU UART0 */
+#define LOONGSON_CPU_THSENS_VEC 14 /* CPU Thsens */
+#define LOONGSON_CPU_HT0_VEC 16 /* CPU HT0 irq vector base number */
+#define LOONGSON_CPU_HT1_VEC 24 /* CPU HT1 irq vector base number */
+
+/* IRQ number definitions */
+#define LOONGSON_LPC_IRQ_BASE 0
+#define LOONGSON_LPC_LAST_IRQ (LOONGSON_LPC_IRQ_BASE + 15)
+
+#define LOONGSON_CPU_IRQ_BASE 16
+#define LOONGSON_CPU_LAST_IRQ (LOONGSON_CPU_IRQ_BASE + 14)
+
+#define LOONGSON_PCH_IRQ_BASE 64
+#define LOONGSON_PCH_ACPI_IRQ (LOONGSON_PCH_IRQ_BASE + 47)
+#define LOONGSON_PCH_LAST_IRQ (LOONGSON_PCH_IRQ_BASE + 64 - 1)
+
+#define LOONGSON_MSI_IRQ_BASE (LOONGSON_PCH_IRQ_BASE + 64)
+#define LOONGSON_MSI_LAST_IRQ (LOONGSON_PCH_IRQ_BASE + 256 - 1)
+
+#define GSI_MIN_LPC_IRQ LOONGSON_LPC_IRQ_BASE
+#define GSI_MAX_LPC_IRQ (LOONGSON_LPC_IRQ_BASE + 16 - 1)
+#define GSI_MIN_CPU_IRQ LOONGSON_CPU_IRQ_BASE
+#define GSI_MAX_CPU_IRQ (LOONGSON_CPU_IRQ_BASE + 48 - 1)
+#define GSI_MIN_PCH_IRQ LOONGSON_PCH_IRQ_BASE
+#define GSI_MAX_PCH_IRQ (LOONGSON_PCH_IRQ_BASE + 256 - 1)
+
+extern int find_pch_pic(u32 gsi);
+extern int eiointc_get_node(int id);
+
+static inline void eiointc_enable(void)
+{
+ uint64_t misc;
+
+ misc = iocsr_read64(LOONGARCH_IOCSR_MISC_FUNC);
+ misc |= IOCSR_MISC_FUNC_EXT_IOI_EN;
+ iocsr_write64(misc, LOONGARCH_IOCSR_MISC_FUNC);
+}
+
+struct acpi_madt_lio_pic;
+struct acpi_madt_eio_pic;
+struct acpi_madt_ht_pic;
+struct acpi_madt_bio_pic;
+struct acpi_madt_msi_pic;
+struct acpi_madt_lpc_pic;
+
+struct irq_domain *loongarch_cpu_irq_init(void);
+
+struct irq_domain *liointc_acpi_init(struct irq_domain *parent,
+ struct acpi_madt_lio_pic *acpi_liointc);
+struct irq_domain *eiointc_acpi_init(struct irq_domain *parent,
+ struct acpi_madt_eio_pic *acpi_eiointc);
+
+struct irq_domain *htvec_acpi_init(struct irq_domain *parent,
+ struct acpi_madt_ht_pic *acpi_htvec);
+struct irq_domain *pch_lpc_acpi_init(struct irq_domain *parent,
+ struct acpi_madt_lpc_pic *acpi_pchlpc);
+struct irq_domain *pch_msi_acpi_init(struct irq_domain *parent,
+ struct acpi_madt_msi_pic *acpi_pchmsi);
+struct irq_domain *pch_pic_acpi_init(struct irq_domain *parent,
+ struct acpi_madt_bio_pic *acpi_pchpic);
+
+extern struct acpi_madt_lio_pic *acpi_liointc;
+extern struct acpi_madt_eio_pic *acpi_eiointc[MAX_IO_PICS];
+
+extern struct acpi_madt_ht_pic *acpi_htintc;
+extern struct acpi_madt_lpc_pic *acpi_pchlpc;
+extern struct acpi_madt_msi_pic *acpi_pchmsi[MAX_IO_PICS];
+extern struct acpi_madt_bio_pic *acpi_pchpic[MAX_IO_PICS];
+
+extern struct irq_domain *cpu_domain;
+extern struct irq_domain *liointc_domain;
+extern struct irq_domain *pch_lpc_domain;
+extern struct irq_domain *pch_msi_domain[MAX_IO_PICS];
+extern struct irq_domain *pch_pic_domain[MAX_IO_PICS];
+
+#include <asm-generic/irq.h>
+
+#endif /* _ASM_IRQ_H */
diff --git a/arch/loongarch/include/asm/irq_regs.h b/arch/loongarch/include/asm/irq_regs.h
new file mode 100644
index 000000000000..3d62d815bf6b
--- /dev/null
+++ b/arch/loongarch/include/asm/irq_regs.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_IRQ_REGS_H
+#define __ASM_IRQ_REGS_H
+
+#define ARCH_HAS_OWN_IRQ_REGS
+
+#include <linux/thread_info.h>
+
+static inline struct pt_regs *get_irq_regs(void)
+{
+ return current_thread_info()->regs;
+}
+
+static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs)
+{
+ struct pt_regs *old_regs;
+
+ old_regs = get_irq_regs();
+ current_thread_info()->regs = new_regs;
+
+ return old_regs;
+}
+
+#endif /* __ASM_IRQ_REGS_H */
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 */
diff --git a/arch/loongarch/include/asm/kdebug.h b/arch/loongarch/include/asm/kdebug.h
new file mode 100644
index 000000000000..d721b4b82fae
--- /dev/null
+++ b/arch/loongarch/include/asm/kdebug.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_LOONGARCH_KDEBUG_H
+#define _ASM_LOONGARCH_KDEBUG_H
+
+#include <linux/notifier.h>
+
+enum die_val {
+ DIE_OOPS = 1,
+ DIE_RI,
+ DIE_FP,
+ DIE_SIMD,
+ DIE_TRAP,
+ DIE_PAGE_FAULT,
+ DIE_BREAK,
+ DIE_SSTEPBP,
+ DIE_UPROBE,
+ DIE_UPROBE_XOL,
+};
+
+#endif /* _ASM_LOONGARCH_KDEBUG_H */
diff --git a/arch/loongarch/include/asm/stackframe.h b/arch/loongarch/include/asm/stackframe.h
new file mode 100644
index 000000000000..44151b878d00
--- /dev/null
+++ b/arch/loongarch/include/asm/stackframe.h
@@ -0,0 +1,212 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_STACKFRAME_H
+#define _ASM_STACKFRAME_H
+
+#include <linux/threads.h>
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/asm-offsets.h>
+#include <asm/loongarch.h>
+#include <asm/thread_info.h>
+
+/* Make the addition of cfi info a little easier. */
+ .macro cfi_rel_offset reg offset=0 docfi=0
+ .if \docfi
+ .cfi_rel_offset \reg, \offset
+ .endif
+ .endm
+
+ .macro cfi_st reg offset=0 docfi=0
+ cfi_rel_offset \reg, \offset, \docfi
+ LONG_S \reg, sp, \offset
+ .endm
+
+ .macro cfi_restore reg offset=0 docfi=0
+ .if \docfi
+ .cfi_restore \reg
+ .endif
+ .endm
+
+ .macro cfi_ld reg offset=0 docfi=0
+ LONG_L \reg, sp, \offset
+ cfi_restore \reg \offset \docfi
+ .endm
+
+ .macro BACKUP_T0T1
+ csrwr t0, EXCEPTION_KS0
+ csrwr t1, EXCEPTION_KS1
+ .endm
+
+ .macro RELOAD_T0T1
+ csrrd t0, EXCEPTION_KS0
+ csrrd t1, EXCEPTION_KS1
+ .endm
+
+ .macro SAVE_TEMP docfi=0
+ RELOAD_T0T1
+ cfi_st t0, PT_R12, \docfi
+ cfi_st t1, PT_R13, \docfi
+ cfi_st t2, PT_R14, \docfi
+ cfi_st t3, PT_R15, \docfi
+ cfi_st t4, PT_R16, \docfi
+ cfi_st t5, PT_R17, \docfi
+ cfi_st t6, PT_R18, \docfi
+ cfi_st t7, PT_R19, \docfi
+ cfi_st t8, PT_R20, \docfi
+ .endm
+
+ .macro SAVE_STATIC docfi=0
+ cfi_st s0, PT_R23, \docfi
+ cfi_st s1, PT_R24, \docfi
+ cfi_st s2, PT_R25, \docfi
+ cfi_st s3, PT_R26, \docfi
+ cfi_st s4, PT_R27, \docfi
+ cfi_st s5, PT_R28, \docfi
+ cfi_st s6, PT_R29, \docfi
+ cfi_st s7, PT_R30, \docfi
+ cfi_st s8, PT_R31, \docfi
+ .endm
+
+/*
+ * get_saved_sp returns the SP for the current CPU by looking in the
+ * kernelsp array for it. It stores the current sp in t0 and loads the
+ * new value in sp.
+ */
+ .macro get_saved_sp docfi=0
+ la.abs t1, kernelsp
+ move t0, sp
+ .if \docfi
+ .cfi_register sp, t0
+ .endif
+ LONG_L sp, t1, 0
+ .endm
+
+ .macro set_saved_sp stackp temp temp2
+ la.abs \temp, kernelsp
+ LONG_S \stackp, \temp, 0
+ .endm
+
+ .macro SAVE_SOME docfi=0
+ csrrd t1, LOONGARCH_CSR_PRMD
+ andi t1, t1, 0x3 /* extract pplv bit */
+ move t0, sp
+ beqz t1, 8f
+ /* Called from user mode, new stack. */
+ get_saved_sp docfi=\docfi
+8:
+ PTR_ADDI sp, sp, -PT_SIZE
+ .if \docfi
+ .cfi_def_cfa sp, 0
+ .endif
+ cfi_st t0, PT_R3, \docfi
+ cfi_rel_offset sp, PT_R3, \docfi
+ LONG_S zero, sp, PT_R0
+ csrrd t0, LOONGARCH_CSR_PRMD
+ LONG_S t0, sp, PT_PRMD
+ csrrd t0, LOONGARCH_CSR_CRMD
+ LONG_S t0, sp, PT_CRMD
+ csrrd t0, LOONGARCH_CSR_EUEN
+ LONG_S t0, sp, PT_EUEN
+ csrrd t0, LOONGARCH_CSR_ECFG
+ LONG_S t0, sp, PT_ECFG
+ csrrd t0, LOONGARCH_CSR_ESTAT
+ PTR_S t0, sp, PT_ESTAT
+ cfi_st ra, PT_R1, \docfi
+ cfi_st a0, PT_R4, \docfi
+ cfi_st a1, PT_R5, \docfi
+ cfi_st a2, PT_R6, \docfi
+ cfi_st a3, PT_R7, \docfi
+ cfi_st a4, PT_R8, \docfi
+ cfi_st a5, PT_R9, \docfi
+ cfi_st a6, PT_R10, \docfi
+ cfi_st a7, PT_R11, \docfi
+ csrrd ra, LOONGARCH_CSR_ERA
+ LONG_S ra, sp, PT_ERA
+ .if \docfi
+ .cfi_rel_offset ra, PT_ERA
+ .endif
+ cfi_st tp, PT_R2, \docfi
+ cfi_st fp, PT_R22, \docfi
+
+ /* Set thread_info if we're coming from user mode */
+ csrrd t0, LOONGARCH_CSR_PRMD
+ andi t0, t0, 0x3 /* extract pplv bit */
+ beqz t0, 9f
+
+ li.d tp, ~_THREAD_MASK
+ and tp, tp, sp
+ cfi_st u0, PT_R21, \docfi
+ csrrd u0, PERCPU_BASE_KS
+9:
+ .endm
+
+ .macro SAVE_ALL docfi=0
+ SAVE_SOME \docfi
+ SAVE_TEMP \docfi
+ SAVE_STATIC \docfi
+ .endm
+
+ .macro RESTORE_TEMP docfi=0
+ cfi_ld t0, PT_R12, \docfi
+ cfi_ld t1, PT_R13, \docfi
+ cfi_ld t2, PT_R14, \docfi
+ cfi_ld t3, PT_R15, \docfi
+ cfi_ld t4, PT_R16, \docfi
+ cfi_ld t5, PT_R17, \docfi
+ cfi_ld t6, PT_R18, \docfi
+ cfi_ld t7, PT_R19, \docfi
+ cfi_ld t8, PT_R20, \docfi
+ .endm
+
+ .macro RESTORE_STATIC docfi=0
+ cfi_ld s0, PT_R23, \docfi
+ cfi_ld s1, PT_R24, \docfi
+ cfi_ld s2, PT_R25, \docfi
+ cfi_ld s3, PT_R26, \docfi
+ cfi_ld s4, PT_R27, \docfi
+ cfi_ld s5, PT_R28, \docfi
+ cfi_ld s6, PT_R29, \docfi
+ cfi_ld s7, PT_R30, \docfi
+ cfi_ld s8, PT_R31, \docfi
+ .endm
+
+ .macro RESTORE_SOME docfi=0
+ LONG_L a0, sp, PT_PRMD
+ andi a0, a0, 0x3 /* extract pplv bit */
+ beqz a0, 8f
+ cfi_ld u0, PT_R21, \docfi
+8:
+ LONG_L a0, sp, PT_ERA
+ csrwr a0, LOONGARCH_CSR_ERA
+ LONG_L a0, sp, PT_PRMD
+ csrwr a0, LOONGARCH_CSR_PRMD
+ cfi_ld ra, PT_R1, \docfi
+ cfi_ld a0, PT_R4, \docfi
+ cfi_ld a1, PT_R5, \docfi
+ cfi_ld a2, PT_R6, \docfi
+ cfi_ld a3, PT_R7, \docfi
+ cfi_ld a4, PT_R8, \docfi
+ cfi_ld a5, PT_R9, \docfi
+ cfi_ld a6, PT_R10, \docfi
+ cfi_ld a7, PT_R11, \docfi
+ cfi_ld tp, PT_R2, \docfi
+ cfi_ld fp, PT_R22, \docfi
+ .endm
+
+ .macro RESTORE_SP_AND_RET docfi=0
+ cfi_ld sp, PT_R3, \docfi
+ ertn
+ .endm
+
+ .macro RESTORE_ALL_AND_RET docfi=0
+ RESTORE_STATIC \docfi
+ RESTORE_TEMP \docfi
+ RESTORE_SOME \docfi
+ RESTORE_SP_AND_RET \docfi
+ .endm
+
+#endif /* _ASM_STACKFRAME_H */
diff --git a/arch/loongarch/include/asm/stacktrace.h b/arch/loongarch/include/asm/stacktrace.h
new file mode 100644
index 000000000000..26483e396ad1
--- /dev/null
+++ b/arch/loongarch/include/asm/stacktrace.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_STACKTRACE_H
+#define _ASM_STACKTRACE_H
+
+#include <asm/asm.h>
+#include <asm/ptrace.h>
+#include <asm/loongarch.h>
+#include <linux/stringify.h>
+
+#define STR_LONG_L __stringify(LONG_L)
+#define STR_LONG_S __stringify(LONG_S)
+#define STR_LONGSIZE __stringify(LONGSIZE)
+
+#define STORE_ONE_REG(r) \
+ STR_LONG_S " $r" __stringify(r)", %1, "STR_LONGSIZE"*"__stringify(r)"\n\t"
+
+#define CSRRD_ONE_REG(reg) \
+ __stringify(csrrd) " %0, "__stringify(reg)"\n\t"
+
+static __always_inline void prepare_frametrace(struct pt_regs *regs)
+{
+ __asm__ __volatile__(
+ /* Save $r1 */
+ STORE_ONE_REG(1)
+ /* Use $r1 to save PC */
+ "pcaddi $r1, 0\n\t"
+ STR_LONG_S " $r1, %0\n\t"
+ /* Restore $r1 */
+ STR_LONG_L " $r1, %1, "STR_LONGSIZE"\n\t"
+ STORE_ONE_REG(2)
+ STORE_ONE_REG(3)
+ STORE_ONE_REG(4)
+ STORE_ONE_REG(5)
+ STORE_ONE_REG(6)
+ STORE_ONE_REG(7)
+ STORE_ONE_REG(8)
+ STORE_ONE_REG(9)
+ STORE_ONE_REG(10)
+ STORE_ONE_REG(11)
+ STORE_ONE_REG(12)
+ STORE_ONE_REG(13)
+ STORE_ONE_REG(14)
+ STORE_ONE_REG(15)
+ STORE_ONE_REG(16)
+ STORE_ONE_REG(17)
+ STORE_ONE_REG(18)
+ STORE_ONE_REG(19)
+ STORE_ONE_REG(20)
+ STORE_ONE_REG(21)
+ STORE_ONE_REG(22)
+ STORE_ONE_REG(23)
+ STORE_ONE_REG(24)
+ STORE_ONE_REG(25)
+ STORE_ONE_REG(26)
+ STORE_ONE_REG(27)
+ STORE_ONE_REG(28)
+ STORE_ONE_REG(29)
+ STORE_ONE_REG(30)
+ STORE_ONE_REG(31)
+ : "=m" (regs->csr_era)
+ : "r" (regs->regs)
+ : "memory");
+ __asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_BADV) : "=r" (regs->csr_badvaddr));
+ __asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_CRMD) : "=r" (regs->csr_crmd));
+ __asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_PRMD) : "=r" (regs->csr_prmd));
+ __asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_EUEN) : "=r" (regs->csr_euen));
+ __asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_ECFG) : "=r" (regs->csr_ecfg));
+ __asm__ __volatile__(CSRRD_ONE_REG(LOONGARCH_CSR_ESTAT) : "=r" (regs->csr_estat));
+}
+
+#endif /* _ASM_STACKTRACE_H */
diff --git a/arch/loongarch/include/uapi/asm/break.h b/arch/loongarch/include/uapi/asm/break.h
new file mode 100644
index 000000000000..bb9b82ba59f2
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/break.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __UAPI_ASM_BREAK_H
+#define __UAPI_ASM_BREAK_H
+
+#define BRK_DEFAULT 0 /* Used as default */
+#define BRK_BUG 1 /* Used by BUG() */
+#define BRK_KDB 2 /* Used in KDB_ENTER() */
+#define BRK_MATHEMU 3 /* Used by FPU emulator */
+#define BRK_USERBP 4 /* User bp (used by debuggers) */
+#define BRK_SSTEPBP 5 /* User bp (used by debuggers) */
+#define BRK_OVERFLOW 6 /* Overflow check */
+#define BRK_DIVZERO 7 /* Divide by zero check */
+#define BRK_RANGE 8 /* Range error check */
+#define BRK_MULOVFL 9 /* Multiply overflow */
+#define BRK_KPROBE_BP 10 /* Kprobe break */
+#define BRK_KPROBE_SSTEPBP 11 /* Kprobe single step break */
+#define BRK_UPROBE_BP 12 /* See <asm/uprobes.h> */
+#define BRK_UPROBE_XOLBP 13 /* See <asm/uprobes.h> */
+
+#endif /* __UAPI_ASM_BREAK_H */
diff --git a/arch/loongarch/kernel/access-helper.h b/arch/loongarch/kernel/access-helper.h
new file mode 100644
index 000000000000..4a35ca81bd08
--- /dev/null
+++ b/arch/loongarch/kernel/access-helper.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/uaccess.h>
+
+static inline int __get_inst(u32 *i, u32 *p, bool user)
+{
+ return user ? get_user(*i, (u32 __user *)p) : get_kernel_nofault(*i, p);
+}
+
+static inline int __get_addr(unsigned long *a, unsigned long *p, bool user)
+{
+ return user ? get_user(*a, (unsigned long __user *)p) : get_kernel_nofault(*a, p);
+}
diff --git a/arch/loongarch/kernel/genex.S b/arch/loongarch/kernel/genex.S
new file mode 100644
index 000000000000..93496852b3cc
--- /dev/null
+++ b/arch/loongarch/kernel/genex.S
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ * Copyright (C) 2002, 2007 Maciej W. Rozycki
+ * Copyright (C) 2001, 2012 MIPS Technologies, Inc. All rights reserved.
+ */
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/loongarch.h>
+#include <asm/regdef.h>
+#include <asm/fpregdef.h>
+#include <asm/stackframe.h>
+#include <asm/thread_info.h>
+
+ .align 5
+SYM_FUNC_START(__arch_cpu_idle)
+ /* start of rollback region */
+ LONG_L t0, tp, TI_FLAGS
+ nop
+ andi t0, t0, _TIF_NEED_RESCHED
+ bnez t0, 1f
+ nop
+ nop
+ nop
+ idle 0
+ /* end of rollback region */
+1: jirl zero, ra, 0
+SYM_FUNC_END(__arch_cpu_idle)
+
+SYM_FUNC_START(handle_vint)
+ BACKUP_T0T1
+ SAVE_ALL
+ la.abs t1, __arch_cpu_idle
+ LONG_L t0, sp, PT_ERA
+ /* 32 byte rollback region */
+ ori t0, t0, 0x1f
+ xori t0, t0, 0x1f
+ bne t0, t1, 1f
+ LONG_S t0, sp, PT_ERA
+1: move a0, sp
+ move a1, sp
+ la.abs t0, do_vint
+ jirl ra, t0, 0
+ RESTORE_ALL_AND_RET
+SYM_FUNC_END(handle_vint)
+
+SYM_FUNC_START(except_vec_cex)
+ b cache_parity_error
+SYM_FUNC_END(except_vec_cex)
+
+ .macro build_prep_badv
+ csrrd t0, LOONGARCH_CSR_BADV
+ PTR_S t0, sp, PT_BVADDR
+ .endm
+
+ .macro build_prep_fcsr
+ movfcsr2gr a1, fcsr0
+ .endm
+
+ .macro build_prep_none
+ .endm
+
+ .macro BUILD_HANDLER exception handler prep
+ .align 5
+ SYM_FUNC_START(handle_\exception)
+ BACKUP_T0T1
+ SAVE_ALL
+ build_prep_\prep
+ move a0, sp
+ la.abs t0, do_\handler
+ jirl ra, t0, 0
+ RESTORE_ALL_AND_RET
+ SYM_FUNC_END(handle_\exception)
+ .endm
+
+ BUILD_HANDLER ade ade badv
+ BUILD_HANDLER ale ale badv
+ BUILD_HANDLER bp bp none
+ BUILD_HANDLER fpe fpe fcsr
+ BUILD_HANDLER fpu fpu none
+ BUILD_HANDLER lsx lsx none
+ BUILD_HANDLER lasx lasx none
+ BUILD_HANDLER lbt lbt none
+ BUILD_HANDLER ri ri none
+ BUILD_HANDLER watch watch none
+ BUILD_HANDLER reserved reserved none /* others */
+
+SYM_FUNC_START(handle_sys)
+ la.abs t0, handle_syscall
+ jirl zero, t0, 0
+SYM_FUNC_END(handle_sys)
diff --git a/arch/loongarch/kernel/irq.c b/arch/loongarch/kernel/irq.c
new file mode 100644
index 000000000000..9bd07edf0bce
--- /dev/null
+++ b/arch/loongarch/kernel/irq.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/atomic.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/kernel_stat.h>
+#include <linux/proc_fs.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+
+#include <asm/irq.h>
+#include <asm/loongson.h>
+#include <asm/setup.h>
+
+DEFINE_PER_CPU(unsigned long, irq_stack);
+
+struct irq_domain *cpu_domain;
+struct irq_domain *liointc_domain;
+struct irq_domain *pch_lpc_domain;
+struct irq_domain *pch_msi_domain[MAX_IO_PICS];
+struct irq_domain *pch_pic_domain[MAX_IO_PICS];
+
+/*
+ * 'what should we do if we get a hw irq event on an illegal vector'.
+ * each architecture has to answer this themselves.
+ */
+void ack_bad_irq(unsigned int irq)
+{
+ pr_warn("Unexpected IRQ # %d\n", irq);
+}
+
+atomic_t irq_err_count;
+
+asmlinkage void spurious_interrupt(void)
+{
+ atomic_inc(&irq_err_count);
+}
+
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+ seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
+ return 0;
+}
+
+void __init init_IRQ(void)
+{
+ int i;
+ unsigned int order = get_order(IRQ_STACK_SIZE);
+ struct page *page;
+
+ clear_csr_ecfg(ECFG0_IM);
+ clear_csr_estat(ESTATF_IP);
+
+ irqchip_init();
+
+ for (i = 0; i < NR_IRQS; i++)
+ irq_set_noprobe(i);
+
+ for_each_possible_cpu(i) {
+ page = alloc_pages_node(cpu_to_node(i), GFP_KERNEL, order);
+
+ per_cpu(irq_stack, i) = (unsigned long)page_address(page);
+ pr_debug("CPU%d IRQ stack at 0x%lx - 0x%lx\n", i,
+ per_cpu(irq_stack, i), per_cpu(irq_stack, i) + IRQ_STACK_SIZE);
+ }
+
+ set_csr_ecfg(ECFGF_IP0 | ECFGF_IP1 | ECFGF_IP2 | ECFGF_IPI | ECFGF_PMC);
+}
diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c
new file mode 100644
index 000000000000..8be071b265b3
--- /dev/null
+++ b/arch/loongarch/kernel/traps.c
@@ -0,0 +1,725 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author: Huacai Chen <chenhuacai@xxxxxxxxxxx>
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/bitops.h>
+#include <linux/bug.h>
+#include <linux/compiler.h>
+#include <linux/context_tracking.h>
+#include <linux/entry-common.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/extable.h>
+#include <linux/mm.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/debug.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/kallsyms.h>
+#include <linux/memblock.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <linux/kgdb.h>
+#include <linux/kdebug.h>
+#include <linux/kprobes.h>
+#include <linux/notifier.h>
+#include <linux/irq.h>
+#include <linux/perf_event.h>
+
+#include <asm/addrspace.h>
+#include <asm/bootinfo.h>
+#include <asm/branch.h>
+#include <asm/break.h>
+#include <asm/cpu.h>
+#include <asm/fpu.h>
+#include <asm/loongarch.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/ptrace.h>
+#include <asm/sections.h>
+#include <asm/siginfo.h>
+#include <asm/stacktrace.h>
+#include <asm/tlb.h>
+#include <asm/types.h>
+
+#include "access-helper.h"
+
+extern asmlinkage void handle_ade(void);
+extern asmlinkage void handle_ale(void);
+extern asmlinkage void handle_sys(void);
+extern asmlinkage void handle_bp(void);
+extern asmlinkage void handle_ri(void);
+extern asmlinkage void handle_fpu(void);
+extern asmlinkage void handle_fpe(void);
+extern asmlinkage void handle_lbt(void);
+extern asmlinkage void handle_lsx(void);
+extern asmlinkage void handle_lasx(void);
+extern asmlinkage void handle_reserved(void);
+extern asmlinkage void handle_watch(void);
+extern asmlinkage void handle_vint(void);
+
+static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
+ const char *loglvl, bool user)
+{
+ unsigned long addr;
+ unsigned long *sp = (unsigned long *)(regs->regs[3] & ~3);
+
+ printk("%sCall Trace:", loglvl);
+#ifdef CONFIG_KALLSYMS
+ printk("%s\n", loglvl);
+#endif
+ while (!kstack_end(sp)) {
+ if (__get_addr(&addr, sp++, user)) {
+ printk("%s (Bad stack address)", loglvl);
+ break;
+ }
+ if (__kernel_text_address(addr))
+ print_ip_sym(loglvl, addr);
+ }
+ printk("%s\n", loglvl);
+}
+
+static void show_stacktrace(struct task_struct *task,
+ const struct pt_regs *regs, const char *loglvl, bool user)
+{
+ int i;
+ const int field = 2 * sizeof(unsigned long);
+ unsigned long stackdata;
+ unsigned long *sp = (unsigned long *)regs->regs[3];
+
+ printk("%sStack :", loglvl);
+ i = 0;
+ while ((unsigned long) sp & (PAGE_SIZE - 1)) {
+ if (i && ((i % (64 / field)) == 0)) {
+ pr_cont("\n");
+ printk("%s ", loglvl);
+ }
+ if (i > 39) {
+ pr_cont(" ...");
+ break;
+ }
+
+ if (__get_addr(&stackdata, sp++, user)) {
+ pr_cont(" (Bad stack address)");
+ break;
+ }
+
+ pr_cont(" %0*lx", field, stackdata);
+ i++;
+ }
+ pr_cont("\n");
+ show_backtrace(task, regs, loglvl, user);
+}
+
+void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
+{
+ struct pt_regs regs;
+
+ regs.csr_crmd = 0;
+ if (sp) {
+ regs.csr_era = 0;
+ regs.regs[1] = 0;
+ regs.regs[3] = (unsigned long)sp;
+ } else {
+ if (!task || task == current)
+ prepare_frametrace(&regs);
+ else {
+ regs.csr_era = task->thread.reg01;
+ regs.regs[1] = 0;
+ regs.regs[3] = task->thread.reg03;
+ regs.regs[22] = task->thread.reg22;
+ }
+ }
+
+ show_stacktrace(task, &regs, loglvl, false);
+}
+
+static void show_code(unsigned int *pc, bool user)
+{
+ long i;
+ unsigned int insn;
+
+ printk("Code:");
+
+ for(i = -3 ; i < 6 ; i++) {
+ if (__get_inst(&insn, pc + i, user)) {
+ pr_cont(" (Bad address in era)\n");
+ break;
+ }
+ pr_cont("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
+ }
+ pr_cont("\n");
+}
+
+static void __show_regs(const struct pt_regs *regs)
+{
+ const int field = 2 * sizeof(unsigned long);
+ unsigned int excsubcode;
+ unsigned int exccode;
+ int i;
+
+ show_regs_print_info(KERN_DEFAULT);
+
+ /*
+ * Saved main processor registers
+ */
+ for (i = 0; i < 32; ) {
+ if ((i % 4) == 0)
+ printk("$%2d :", i);
+ pr_cont(" %0*lx", field, regs->regs[i]);
+
+ i++;
+ if ((i % 4) == 0)
+ pr_cont("\n");
+ }
+
+ /*
+ * Saved csr registers
+ */
+ printk("era : %0*lx %pS\n", field, regs->csr_era,
+ (void *) regs->csr_era);
+ printk("ra : %0*lx %pS\n", field, regs->regs[1],
+ (void *) regs->regs[1]);
+
+ printk("CSR crmd: %08lx ", regs->csr_crmd);
+ printk("CSR prmd: %08lx ", regs->csr_prmd);
+ printk("CSR euen: %08lx ", regs->csr_euen);
+ printk("CSR ecfg: %08lx ", regs->csr_ecfg);
+ printk("CSR estat: %08lx ", regs->csr_estat);
+
+ pr_cont("\n");
+
+ exccode = ((regs->csr_estat) & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT;
+ excsubcode = ((regs->csr_estat) & CSR_ESTAT_ESUBCODE) >> CSR_ESTAT_ESUBCODE_SHIFT;
+ printk("ExcCode : %x (SubCode %x)\n", exccode, excsubcode);
+
+ if (exccode >= EXCCODE_TLBL && exccode <= EXCCODE_ALE)
+ printk("BadVA : %0*lx\n", field, regs->csr_badvaddr);
+
+ printk("PrId : %08x (%s)\n", read_cpucfg(LOONGARCH_CPUCFG0),
+ cpu_family_string());
+}
+
+void show_regs(struct pt_regs *regs)
+{
+ __show_regs((struct pt_regs *)regs);
+ dump_stack();
+}
+
+void show_registers(struct pt_regs *regs)
+{
+ __show_regs(regs);
+ print_modules();
+ printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
+ current->comm, current->pid, current_thread_info(), current);
+
+ show_stacktrace(current, regs, KERN_DEFAULT, user_mode(regs));
+ show_code((void *)regs->csr_era, user_mode(regs));
+ printk("\n");
+}
+
+static DEFINE_RAW_SPINLOCK(die_lock);
+
+void __noreturn die(const char *str, struct pt_regs *regs)
+{
+ static int die_counter;
+ int sig = SIGSEGV;
+
+ oops_enter();
+
+ if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
+ SIGSEGV) == NOTIFY_STOP)
+ sig = 0;
+
+ console_verbose();
+ raw_spin_lock_irq(&die_lock);
+ bust_spinlocks(1);
+
+ printk("%s[#%d]:\n", str, ++die_counter);
+ show_registers(regs);
+ add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
+ raw_spin_unlock_irq(&die_lock);
+
+ oops_exit();
+
+ if (in_interrupt())
+ panic("Fatal exception in interrupt");
+
+ if (panic_on_oops)
+ panic("Fatal exception");
+
+ make_task_dead(sig);
+}
+
+static inline void setup_vint_size(unsigned int size)
+{
+ unsigned int vs;
+
+ vs = ilog2(size/4);
+
+ if (vs == 0 || vs > 7)
+ panic("vint_size %d Not support yet", vs);
+
+ csr_xchg32(vs<<CSR_ECFG_VS_SHIFT, CSR_ECFG_VS, LOONGARCH_CSR_ECFG);
+}
+
+/*
+ * Send SIGFPE according to FCSR Cause bits, which must have already
+ * been masked against Enable bits. This is impotant as Inexact can
+ * happen together with Overflow or Underflow, and `ptrace' can set
+ * any bits.
+ */
+void force_fcsr_sig(unsigned long fcsr, void __user *fault_addr,
+ struct task_struct *tsk)
+{
+ int si_code = FPE_FLTUNK;
+
+ if (fcsr & FPU_CSR_INV_X)
+ si_code = FPE_FLTINV;
+ else if (fcsr & FPU_CSR_DIV_X)
+ si_code = FPE_FLTDIV;
+ else if (fcsr & FPU_CSR_OVF_X)
+ si_code = FPE_FLTOVF;
+ else if (fcsr & FPU_CSR_UDF_X)
+ si_code = FPE_FLTUND;
+ else if (fcsr & FPU_CSR_INE_X)
+ si_code = FPE_FLTRES;
+
+ force_sig_fault(SIGFPE, si_code, fault_addr);
+}
+
+int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcsr)
+{
+ int si_code;
+
+ switch (sig) {
+ case 0:
+ return 0;
+
+ case SIGFPE:
+ force_fcsr_sig(fcsr, fault_addr, current);
+ return 1;
+
+ case SIGBUS:
+ force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr);
+ return 1;
+
+ case SIGSEGV:
+ mmap_read_lock(current->mm);
+ if (vma_lookup(current->mm, (unsigned long)fault_addr))
+ si_code = SEGV_ACCERR;
+ else
+ si_code = SEGV_MAPERR;
+ mmap_read_unlock(current->mm);
+ force_sig_fault(SIGSEGV, si_code, fault_addr);
+ return 1;
+
+ default:
+ force_sig(sig);
+ return 1;
+ }
+}
+
+/*
+ * Delayed fp exceptions when doing a lazy ctx switch
+ */
+asmlinkage void noinstr do_fpe(struct pt_regs *regs, unsigned long fcsr)
+{
+ int sig;
+ void __user *fault_addr;
+ irqentry_state_t state = irqentry_enter(regs);
+
+ if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
+ SIGFPE) == NOTIFY_STOP)
+ goto out;
+
+ /* Clear FCSR.Cause before enabling interrupts */
+ write_fcsr(LOONGARCH_FCSR0, fcsr & ~mask_fcsr_x(fcsr));
+ local_irq_enable();
+
+ die_if_kernel("FP exception in kernel code", regs);
+
+ sig = SIGFPE;
+ fault_addr = (void __user *) regs->csr_era;
+
+ /* Send a signal if required. */
+ process_fpemu_return(sig, fault_addr, fcsr);
+
+out:
+ local_irq_disable();
+ irqentry_exit(regs, state);
+}
+
+asmlinkage void noinstr do_ade(struct pt_regs *regs)
+{
+ irqentry_state_t state = irqentry_enter(regs);
+
+ die_if_kernel("Kernel ade access", regs);
+ force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)regs->csr_badvaddr);
+
+ irqentry_exit(regs, state);
+}
+
+asmlinkage void noinstr do_ale(struct pt_regs *regs)
+{
+ irqentry_state_t state = irqentry_enter(regs);
+
+ die_if_kernel("Kernel ale access", regs);
+ force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)regs->csr_badvaddr);
+
+ irqentry_exit(regs, state);
+}
+
+asmlinkage void noinstr do_bp(struct pt_regs *regs)
+{
+ bool user = user_mode(regs);
+ unsigned int opcode, bcode;
+ unsigned long era = exception_era(regs);
+ irqentry_state_t state = irqentry_enter(regs);
+
+ local_irq_enable();
+ current->thread.trap_nr = read_csr_excode();
+ if (__get_inst(&opcode, (u32 *)era, user))
+ goto out_sigsegv;
+
+ bcode = (opcode & 0x7fff);
+
+ /*
+ * notify the kprobe handlers, if instruction is likely to
+ * pertain to them.
+ */
+ switch (bcode) {
+ case BRK_KPROBE_BP:
+ if (notify_die(DIE_BREAK, "Kprobe", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ case BRK_KPROBE_SSTEPBP:
+ if (notify_die(DIE_SSTEPBP, "Kprobe_SingleStep", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ case BRK_UPROBE_BP:
+ if (notify_die(DIE_UPROBE, "Uprobe", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ case BRK_UPROBE_XOLBP:
+ if (notify_die(DIE_UPROBE_XOL, "Uprobe_XOL", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ default:
+ if (notify_die(DIE_TRAP, "Break", regs, bcode,
+ current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
+ goto out;
+ else
+ break;
+ }
+
+ switch (bcode) {
+ case BRK_BUG:
+ die_if_kernel("Kernel bug detected", regs);
+ force_sig(SIGTRAP);
+ break;
+ case BRK_DIVZERO:
+ die_if_kernel("Break instruction in kernel code", regs);
+ force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->csr_era);
+ break;
+ case BRK_OVERFLOW:
+ die_if_kernel("Break instruction in kernel code", regs);
+ force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->csr_era);
+ break;
+ default:
+ die_if_kernel("Break instruction in kernel code", regs);
+ force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->csr_era);
+ break;
+ }
+
+out:
+ local_irq_disable();
+ irqentry_exit(regs, state);
+ return;
+
+out_sigsegv:
+ force_sig(SIGSEGV);
+ goto out;
+}
+
+asmlinkage void noinstr do_watch(struct pt_regs *regs)
+{
+ pr_warn("Hardware watch point handler not implemented!\n");
+}
+
+asmlinkage void noinstr do_ri(struct pt_regs *regs)
+{
+ int status = -1;
+ unsigned int opcode = 0;
+ unsigned int __user *era = (unsigned int __user *)exception_era(regs);
+ unsigned long old_era = regs->csr_era;
+ unsigned long old_ra = regs->regs[1];
+ irqentry_state_t state = irqentry_enter(regs);
+
+ local_irq_enable();
+ current->thread.trap_nr = read_csr_excode();
+
+ if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
+ SIGILL) == NOTIFY_STOP)
+ goto out;
+
+ die_if_kernel("Reserved instruction in kernel code", regs);
+
+ if (unlikely(compute_return_era(regs) < 0))
+ goto out;
+
+ if (unlikely(get_user(opcode, era) < 0)) {
+ status = SIGSEGV;
+ current->thread.error_code = 1;
+ }
+
+ if (status < 0)
+ status = SIGILL;
+
+ if (unlikely(status > 0)) {
+ regs->csr_era = old_era; /* Undo skip-over. */
+ regs->regs[1] = old_ra;
+ force_sig(status);
+ }
+
+out:
+ local_irq_disable();
+ irqentry_exit(regs, state);
+}
+
+static void init_restore_fp(void)
+{
+ if (!used_math()) {
+ /* First time FP context user. */
+ init_fpu();
+ } else {
+ /* This task has formerly used the FP context */
+ if (!is_fpu_owner())
+ own_fpu_inatomic(1);
+ }
+
+ BUG_ON(!is_fp_enabled());
+}
+
+asmlinkage void noinstr do_fpu(struct pt_regs *regs)
+{
+ irqentry_state_t state = irqentry_enter(regs);
+
+ local_irq_enable();
+ die_if_kernel("do_fpu invoked from kernel context!", regs);
+
+ preempt_disable();
+ init_restore_fp();
+ preempt_enable();
+
+ local_irq_disable();
+ irqentry_exit(regs, state);
+}
+
+asmlinkage void noinstr do_lsx(struct pt_regs *regs)
+{
+ irqentry_state_t state = irqentry_enter(regs);
+
+ local_irq_enable();
+ force_sig(SIGILL);
+ local_irq_disable();
+
+ irqentry_exit(regs, state);
+}
+
+asmlinkage void noinstr do_lasx(struct pt_regs *regs)
+{
+ irqentry_state_t state = irqentry_enter(regs);
+
+ local_irq_enable();
+ force_sig(SIGILL);
+ local_irq_disable();
+
+ irqentry_exit(regs, state);
+}
+
+asmlinkage void noinstr do_lbt(struct pt_regs *regs)
+{
+ irqentry_state_t state = irqentry_enter(regs);
+
+ local_irq_enable();
+ force_sig(SIGILL);
+ local_irq_disable();
+
+ irqentry_exit(regs, state);
+}
+
+asmlinkage void noinstr do_reserved(struct pt_regs *regs)
+{
+ irqentry_state_t state = irqentry_enter(regs);
+
+ local_irq_enable();
+ /*
+ * Game over - no way to handle this if it ever occurs. Most probably
+ * caused by a fatal error after another hardware/software error.
+ */
+ pr_err("Caught reserved exception %u on pid:%d [%s] - should not happen\n",
+ read_csr_excode(), current->pid, current->comm);
+ die_if_kernel("do_reserved exception", regs);
+ force_sig(SIGUNUSED);
+
+ local_irq_disable();
+
+ irqentry_exit(regs, state);
+}
+
+asmlinkage void cache_parity_error(void)
+{
+ /* For the moment, report the problem and hang. */
+ pr_err("Cache error exception:\n");
+ pr_err("csr_merrctl == %08x\n", csr_read32(LOONGARCH_CSR_MERRCTL));
+ pr_err("csr_merrera == %016llx\n", csr_read64(LOONGARCH_CSR_MERRERA));
+ panic("Can't handle the cache error!");
+}
+
+asmlinkage void noinstr handle_loongarch_irq(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs;
+
+ irq_enter_rcu();
+ old_regs = set_irq_regs(regs);
+ handle_arch_irq(regs);
+ set_irq_regs(old_regs);
+ irq_exit_rcu();
+}
+
+asmlinkage void noinstr do_vint(struct pt_regs *regs, unsigned long sp)
+{
+ register int cpu;
+ register unsigned long stack;
+ irqentry_state_t state = irqentry_enter(regs);
+
+ cpu = smp_processor_id();
+
+ if (on_irq_stack(cpu, sp))
+ handle_loongarch_irq(regs);
+ else {
+ stack = per_cpu(irq_stack, cpu) + IRQ_STACK_START;
+
+ /* Save task's sp on IRQ stack for unwinding */
+ *(unsigned long *)stack = sp;
+
+ __asm__ __volatile__(
+ "move $s0, $sp \n" /* Preserve sp */
+ "move $sp, %[stk] \n" /* Switch stack */
+ "move $a0, %[regs] \n"
+ "bl handle_loongarch_irq \n"
+ "move $sp, $s0 \n" /* Restore sp */
+ : /* No outputs */
+ : [stk] "r" (stack), [regs] "r" (regs)
+ : "$a0", "$a1", "$a2", "$a3", "$a4", "$a5", "$a6", "$a7", "$s0",
+ "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8",
+ "memory");
+ }
+
+ irqentry_exit(regs, state);
+}
+
+extern void tlb_init(void);
+extern void cache_error_setup(void);
+
+unsigned long eentry;
+unsigned long tlbrentry;
+
+long exception_handlers[VECSIZE * 128 / sizeof(long)] __aligned(SZ_64K);
+
+static void configure_exception_vector(void)
+{
+ eentry = (unsigned long)exception_handlers;
+ tlbrentry = (unsigned long)exception_handlers + 80*VECSIZE;
+
+ csr_write64(eentry, LOONGARCH_CSR_EENTRY);
+ csr_write64(eentry, LOONGARCH_CSR_MERRENTRY);
+ csr_write64(tlbrentry, LOONGARCH_CSR_TLBRENTRY);
+}
+
+void per_cpu_trap_init(int cpu)
+{
+ unsigned int i;
+
+ setup_vint_size(VECSIZE);
+
+ configure_exception_vector();
+
+ if (!cpu_data[cpu].asid_cache)
+ cpu_data[cpu].asid_cache = asid_first_version(cpu);
+
+ mmgrab(&init_mm);
+ current->active_mm = &init_mm;
+ BUG_ON(current->mm);
+ enter_lazy_tlb(&init_mm, current);
+
+ /* Initialise exception handlers */
+ if (cpu == 0)
+ for (i = 0; i < 64; i++)
+ set_handler(i * VECSIZE, handle_reserved, VECSIZE);
+
+ tlb_init();
+ cpu_cache_init();
+}
+
+/* Install CPU exception handler */
+void set_handler(unsigned long offset, void *addr, unsigned long size)
+{
+ memcpy((void *)(eentry + offset), addr, size);
+ local_flush_icache_range(eentry + offset, eentry + offset + size);
+}
+
+static const char panic_null_cerr[] =
+ "Trying to set NULL cache error exception handler\n";
+
+/*
+ * Install uncached CPU exception handler.
+ * This is suitable only for the cache error exception which is the only
+ * exception handler that is being run uncached.
+ */
+void set_merr_handler(unsigned long offset, void *addr, unsigned long size)
+{
+ unsigned long uncached_eentry = TO_UNCACHE(__pa(eentry));
+
+ if (!addr)
+ panic(panic_null_cerr);
+
+ memcpy((void *)(uncached_eentry + offset), addr, size);
+}
+
+void __init trap_init(void)
+{
+ long i;
+
+ /* Set interrupt vector handler */
+ for (i = EXCCODE_INT_START; i < EXCCODE_INT_END; i++)
+ set_handler(i * VECSIZE, handle_vint, VECSIZE);
+
+ set_handler(EXCCODE_ADE * VECSIZE, handle_ade, VECSIZE);
+ set_handler(EXCCODE_ALE * VECSIZE, handle_ale, VECSIZE);
+ set_handler(EXCCODE_SYS * VECSIZE, handle_sys, VECSIZE);
+ set_handler(EXCCODE_BP * VECSIZE, handle_bp, VECSIZE);
+ set_handler(EXCCODE_INE * VECSIZE, handle_ri, VECSIZE);
+ set_handler(EXCCODE_IPE * VECSIZE, handle_ri, VECSIZE);
+ set_handler(EXCCODE_FPDIS * VECSIZE, handle_fpu, VECSIZE);
+ set_handler(EXCCODE_LSXDIS * VECSIZE, handle_lsx, VECSIZE);
+ set_handler(EXCCODE_LASXDIS * VECSIZE, handle_lasx, VECSIZE);
+ set_handler(EXCCODE_FPE * VECSIZE, handle_fpe, VECSIZE);
+ set_handler(EXCCODE_BTDIS * VECSIZE, handle_lbt, VECSIZE);
+ set_handler(EXCCODE_WATCH * VECSIZE, handle_watch, VECSIZE);
+
+ cache_error_setup();
+
+ local_flush_icache_range(eentry, eentry + 0x400);
+}
--
2.27.0