forked from Mirrors/opensbi
5a7bd0c88d
We remove mcause, scratch and hartid parameters from various functions for illegal instruction handling because we can always get current HART id and current scratch pointer using just one CSR access. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
145 lines
3.4 KiB
C
145 lines
3.4 KiB
C
/*
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* SPDX-License-Identifier: BSD-2-Clause
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*
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* Copyright (c) 2019 Western Digital Corporation or its affiliates.
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*
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* Authors:
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* Anup Patel <anup.patel@wdc.com>
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*/
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#include <sbi/riscv_asm.h>
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#include <sbi/riscv_encoding.h>
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#include <sbi/sbi_bitops.h>
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#include <sbi/sbi_emulate_csr.h>
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#include <sbi/sbi_error.h>
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#include <sbi/sbi_illegal_insn.h>
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#include <sbi/sbi_trap.h>
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#include <sbi/sbi_unpriv.h>
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typedef int (*illegal_insn_func)(ulong insn, struct sbi_trap_regs *regs);
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static int truly_illegal_insn(ulong insn, struct sbi_trap_regs *regs)
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{
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struct sbi_trap_info trap;
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trap.epc = regs->mepc;
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trap.cause = CAUSE_ILLEGAL_INSTRUCTION;
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trap.tval = insn;
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trap.tval2 = 0;
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trap.tinst = 0;
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return sbi_trap_redirect(regs, &trap);
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}
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static int system_opcode_insn(ulong insn, struct sbi_trap_regs *regs)
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{
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int do_write, rs1_num = (insn >> 15) & 0x1f;
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ulong rs1_val = GET_RS1(insn, regs);
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int csr_num = (u32)insn >> 20;
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ulong csr_val, new_csr_val;
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/*
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* WFI always traps as illegal instruction when executed from
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* VS/VU mode so we just forward it to HS-mode.
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*/
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#if __riscv_xlen == 32
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if ((regs->mstatusH & MSTATUSH_MPV) &&
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#else
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if ((regs->mstatus & MSTATUS_MPV) &&
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#endif
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(insn & INSN_MASK_WFI) == INSN_MATCH_WFI)
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return truly_illegal_insn(insn, regs);
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if (sbi_emulate_csr_read(csr_num, regs, &csr_val))
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return truly_illegal_insn(insn, regs);
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do_write = rs1_num;
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switch (GET_RM(insn)) {
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case 1:
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new_csr_val = rs1_val;
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do_write = 1;
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break;
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case 2:
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new_csr_val = csr_val | rs1_val;
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break;
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case 3:
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new_csr_val = csr_val & ~rs1_val;
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break;
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case 5:
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new_csr_val = rs1_num;
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do_write = 1;
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break;
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case 6:
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new_csr_val = csr_val | rs1_num;
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break;
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case 7:
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new_csr_val = csr_val & ~rs1_num;
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break;
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default:
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return truly_illegal_insn(insn, regs);
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};
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if (do_write && sbi_emulate_csr_write(csr_num, regs, new_csr_val))
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return truly_illegal_insn(insn, regs);
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SET_RD(insn, regs, csr_val);
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regs->mepc += 4;
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return 0;
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}
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static illegal_insn_func illegal_insn_table[32] = {
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truly_illegal_insn, /* 0 */
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truly_illegal_insn, /* 1 */
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truly_illegal_insn, /* 2 */
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truly_illegal_insn, /* 3 */
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truly_illegal_insn, /* 4 */
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truly_illegal_insn, /* 5 */
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truly_illegal_insn, /* 6 */
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truly_illegal_insn, /* 7 */
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truly_illegal_insn, /* 8 */
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truly_illegal_insn, /* 9 */
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truly_illegal_insn, /* 10 */
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truly_illegal_insn, /* 11 */
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truly_illegal_insn, /* 12 */
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truly_illegal_insn, /* 13 */
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truly_illegal_insn, /* 14 */
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truly_illegal_insn, /* 15 */
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truly_illegal_insn, /* 16 */
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truly_illegal_insn, /* 17 */
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truly_illegal_insn, /* 18 */
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truly_illegal_insn, /* 19 */
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truly_illegal_insn, /* 20 */
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truly_illegal_insn, /* 21 */
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truly_illegal_insn, /* 22 */
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truly_illegal_insn, /* 23 */
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truly_illegal_insn, /* 24 */
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truly_illegal_insn, /* 25 */
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truly_illegal_insn, /* 26 */
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truly_illegal_insn, /* 27 */
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system_opcode_insn, /* 28 */
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truly_illegal_insn, /* 29 */
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truly_illegal_insn, /* 30 */
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truly_illegal_insn /* 31 */
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};
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int sbi_illegal_insn_handler(ulong insn, struct sbi_trap_regs *regs)
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{
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struct sbi_trap_info uptrap;
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if (unlikely((insn & 3) != 3)) {
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if (insn == 0) {
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insn = sbi_get_insn(regs->mepc, &uptrap);
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if (uptrap.cause) {
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uptrap.epc = regs->mepc;
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return sbi_trap_redirect(regs, &uptrap);
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}
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}
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if ((insn & 3) != 3)
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return truly_illegal_insn(insn, regs);
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}
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return illegal_insn_table[(insn & 0x7c) >> 2](insn, regs);
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}
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