在2022年6月1日六月 上午10:59，Huacai Chen写道：
> Add the exception and interrupt handling machanism for basic LoongArch
> support.
>
> Reviewed-by: WANG Xuerui <git@xxxxxxxxxx>
> Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
Reviewed-by: Jiaxun Yang <jiaxun.yang@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(®s);
> + 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, ®s, 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
--
- Jiaxun
