diff options
Diffstat (limited to 'arch/riscv/lib/interrupts.c')
| -rw-r--r-- | arch/riscv/lib/interrupts.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/arch/riscv/lib/interrupts.c b/arch/riscv/lib/interrupts.c new file mode 100644 index 00000000000..7350e2ced85 --- /dev/null +++ b/arch/riscv/lib/interrupts.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2016-17 Microsemi Corporation. + * Padmarao Begari, Microsemi Corporation <padmarao.begari@microsemi.com> + * + * Copyright (C) 2017 Andes Technology Corporation + * Rick Chen, Andes Technology Corporation <rick@andestech.com> + * + * Copyright (C) 2019 Sean Anderson <seanga2@gmail.com> + */ + +#include <linux/compat.h> +#include <efi_loader.h> +#include <hang.h> +#include <interrupt.h> +#include <irq_func.h> +#include <asm/global_data.h> +#include <asm/ptrace.h> +#include <asm/system.h> +#include <asm/encoding.h> +#include <semihosting.h> + +DECLARE_GLOBAL_DATA_PTR; + +static struct resume_data *resume; + +void set_resume(struct resume_data *data) +{ + resume = data; +} + +static void show_efi_loaded_images(uintptr_t epc) +{ + efi_print_image_infos((void *)epc); +} + +static void show_regs(struct pt_regs *regs) +{ +#ifdef CONFIG_SHOW_REGS + printf("\nSP: " REG_FMT " GP: " REG_FMT " TP: " REG_FMT "\n", + regs->sp, regs->gp, regs->tp); + printf("T0: " REG_FMT " T1: " REG_FMT " T2: " REG_FMT "\n", + regs->t0, regs->t1, regs->t2); + printf("S0: " REG_FMT " S1: " REG_FMT " A0: " REG_FMT "\n", + regs->s0, regs->s1, regs->a0); + printf("A1: " REG_FMT " A2: " REG_FMT " A3: " REG_FMT "\n", + regs->a1, regs->a2, regs->a3); + printf("A4: " REG_FMT " A5: " REG_FMT " A6: " REG_FMT "\n", + regs->a4, regs->a5, regs->a6); + printf("A7: " REG_FMT " S2: " REG_FMT " S3: " REG_FMT "\n", + regs->a7, regs->s2, regs->s3); + printf("S4: " REG_FMT " S5: " REG_FMT " S6: " REG_FMT "\n", + regs->s4, regs->s5, regs->s6); + printf("S7: " REG_FMT " S8: " REG_FMT " S9: " REG_FMT "\n", + regs->s7, regs->s8, regs->s9); + printf("S10: " REG_FMT " S11: " REG_FMT " T3: " REG_FMT "\n", + regs->s10, regs->s11, regs->t3); + printf("T4: " REG_FMT " T5: " REG_FMT " T6: " REG_FMT "\n", + regs->t4, regs->t5, regs->t6); +#endif +} + +#if defined(CONFIG_FRAMEPOINTER) || defined(CONFIG_SPL_FRAMEPOINTER) +static void show_backtrace(struct pt_regs *regs) +{ + uintptr_t *fp = (uintptr_t *)regs->s0; + unsigned count = 0; + ulong ra; + + printf("backtrace:\n"); + + /* there are a few entry points where the s0 register is + * set to gd, so to avoid changing those, just abort if + * the value is the same */ + while (fp != NULL && fp != (uintptr_t *)gd) { + ra = fp[-1]; + printf("backtrace %2d: FP: " REG_FMT " RA: " REG_FMT, + count, (ulong)fp, ra); + + if (gd && gd->flags & GD_FLG_RELOC) + printf(" - RA: " REG_FMT " reloc adjusted\n", + ra - gd->reloc_off); + else + printf("\n"); + + fp = (uintptr_t *)fp[-2]; + count++; + } +} +#else +static void show_backtrace(struct pt_regs *regs) +{ + printf("No backtrace support enabled\n"); +} +#endif + +/** + * instr_len() - get instruction length + * + * @i: low 16 bits of the instruction + * Return: number of u16 in instruction + */ +static int instr_len(u16 i) +{ + if ((i & 0x03) != 0x03) + return 1; + /* Instructions with more than 32 bits are not yet specified */ + return 2; +} + +/** + * show_code() - display code leading to exception + * + * @epc: program counter + */ +static void show_code(ulong epc) +{ + u16 *pos = (u16 *)(epc & ~1UL); + int i, len = instr_len(*pos); + + printf("\nCode: "); + for (i = -8; i; ++i) + printf("%04x ", pos[i]); + printf("("); + for (i = 0; i < len; ++i) + printf("%04x%s", pos[i], i + 1 == len ? ")\n" : " "); +} + +static void _exit_trap(ulong code, ulong epc, ulong tval, struct pt_regs *regs) +{ + static const char * const exception_code[] = { + "Instruction address misaligned", + "Instruction access fault", + "Illegal instruction", + "Breakpoint", + "Load address misaligned", + "Load access fault", + "Store/AMO address misaligned", + "Store/AMO access fault", + "Environment call from U-mode", + "Environment call from S-mode", + "Reserved", + "Environment call from M-mode", + "Instruction page fault", + "Load page fault", + "Reserved", + "Store/AMO page fault", + }; + + if (resume) { + resume->code = code; + longjmp(resume->jump, 1); + } + + if (code < ARRAY_SIZE(exception_code)) + printf("Unhandled exception: %s\n", exception_code[code]); + else + printf("Unhandled exception code: %ld\n", code); + + printf("EPC: " REG_FMT " RA: " REG_FMT " TVAL: " REG_FMT "\n", + epc, regs->ra, tval); + /* Print relocation adjustments, but only if gd is initialized */ + if (gd && gd->flags & GD_FLG_RELOC) + printf("EPC: " REG_FMT " RA: " REG_FMT " reloc adjusted\n", + epc - gd->reloc_off, regs->ra - gd->reloc_off); + + show_regs(regs); + show_backtrace(regs); + show_code(epc); + show_efi_loaded_images(epc); + panic("\n"); +} + +int interrupt_init(void) +{ + return 0; +} + +/* + * enable interrupts + */ +void enable_interrupts(void) +{ +} + +/* + * disable interrupts + */ +int disable_interrupts(void) +{ + return 0; +} + +ulong handle_trap(ulong cause, ulong epc, ulong tval, struct pt_regs *regs) +{ + ulong is_irq, irq; + + /* An UEFI application may have changed gd. Restore U-Boot's gd. */ + efi_restore_gd(); + + if (cause == CAUSE_BREAKPOINT && + CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)) { + ulong pre_addr = epc - 4, post_addr = epc + 4; + + /* Check for prior and post addresses to be in same page. */ + if ((pre_addr & ~(PAGE_SIZE - 1)) == + (post_addr & ~(PAGE_SIZE - 1))) { + u32 pre = *(u32 *)pre_addr; + u32 post = *(u32 *)post_addr; + + /* Check for semihosting, i.e.: + * slli zero,zero,0x1f + * ebreak + * srai zero,zero,0x7 + */ + if (pre == 0x01f01013 && post == 0x40705013) { + disable_semihosting(); + epc += 4; + return epc; + } + } + } + + is_irq = (cause & MCAUSE_INT); + irq = (cause & ~MCAUSE_INT); + + if (is_irq) { + switch (irq) { + case IRQ_M_EXT: + case IRQ_S_EXT: + external_interrupt(0); /* handle external interrupt */ + break; + case IRQ_M_TIMER: + case IRQ_S_TIMER: + timer_interrupt(0); /* handle timer interrupt */ + break; + default: + _exit_trap(cause, epc, tval, regs); + break; + }; + } else { + _exit_trap(cause, epc, tval, regs); + } + + return epc; +} + +/* + *Entry Point for PLIC Interrupt Handler + */ +__attribute__((weak)) void external_interrupt(struct pt_regs *regs) +{ +} + +__attribute__((weak)) void timer_interrupt(struct pt_regs *regs) +{ +} |