// SPDX-License-Identifier: GPL-2.0-only
/*
 * BPF JIT compiler for LoongArch
 *
 * Copyright (C) 2022 Loongson Technology Corporation Limited
 */
#include <linux/memory.h>
#include "bpf_jit.h"

#define LOONGARCH_MAX_REG_ARGS 8

#define LOONGARCH_LONG_JUMP_NINSNS 5
#define LOONGARCH_LONG_JUMP_NBYTES (LOONGARCH_LONG_JUMP_NINSNS * 4)

#define LOONGARCH_FENTRY_NINSNS 2
#define LOONGARCH_FENTRY_NBYTES (LOONGARCH_FENTRY_NINSNS * 4)
#define LOONGARCH_BPF_FENTRY_NBYTES (LOONGARCH_LONG_JUMP_NINSNS * 4)

#define REG_TCC         LOONGARCH_GPR_A6
#define REG_ARENA       LOONGARCH_GPR_S6 /* For storing arena_vm_start */
#define BPF_TAIL_CALL_CNT_PTR_STACK_OFF(stack) (round_up(stack, 16) - 80)

static const int regmap[] = {
        /* return value from in-kernel function, and exit value for eBPF program */
        [BPF_REG_0] = LOONGARCH_GPR_A5,
        /* arguments from eBPF program to in-kernel function */
        [BPF_REG_1] = LOONGARCH_GPR_A0,
        [BPF_REG_2] = LOONGARCH_GPR_A1,
        [BPF_REG_3] = LOONGARCH_GPR_A2,
        [BPF_REG_4] = LOONGARCH_GPR_A3,
        [BPF_REG_5] = LOONGARCH_GPR_A4,
        /* callee saved registers that in-kernel function will preserve */
        [BPF_REG_6] = LOONGARCH_GPR_S0,
        [BPF_REG_7] = LOONGARCH_GPR_S1,
        [BPF_REG_8] = LOONGARCH_GPR_S2,
        [BPF_REG_9] = LOONGARCH_GPR_S3,
        /* read-only frame pointer to access stack */
        [BPF_REG_FP] = LOONGARCH_GPR_S4,
        /* temporary register for blinding constants */
        [BPF_REG_AX] = LOONGARCH_GPR_T0,
};

static void prepare_bpf_tail_call_cnt(struct jit_ctx *ctx, int *store_offset)
{
        const struct bpf_prog *prog = ctx->prog;
        const bool is_main_prog = !bpf_is_subprog(prog);

        if (is_main_prog) {
                /*
                 * LOONGARCH_GPR_T3 = MAX_TAIL_CALL_CNT
                 * if (REG_TCC > T3 )
                 *      std REG_TCC -> LOONGARCH_GPR_SP + store_offset
                 * else
                 *      std REG_TCC -> LOONGARCH_GPR_SP + store_offset
                 *      REG_TCC = LOONGARCH_GPR_SP + store_offset
                 *
                 * std REG_TCC -> LOONGARCH_GPR_SP + store_offset
                 *
                 * The purpose of this code is to first push the TCC into stack,
                 * and then push the address of TCC into stack.
                 * In cases where bpf2bpf and tailcall are used in combination,
                 * the value in REG_TCC may be a count or an address,
                 * these two cases need to be judged and handled separately.
                 */
                emit_insn(ctx, addid, LOONGARCH_GPR_T3, LOONGARCH_GPR_ZERO, MAX_TAIL_CALL_CNT);
                *store_offset -= sizeof(long);

                emit_cond_jmp(ctx, BPF_JGT, REG_TCC, LOONGARCH_GPR_T3, 4);

                /*
                 * If REG_TCC < MAX_TAIL_CALL_CNT, the value in REG_TCC is a count,
                 * push tcc into stack
                 */
                emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_SP, *store_offset);

                /* Push the address of TCC into the REG_TCC */
                emit_insn(ctx, addid, REG_TCC, LOONGARCH_GPR_SP, *store_offset);

                emit_uncond_jmp(ctx, 2);

                /*
                 * If REG_TCC > MAX_TAIL_CALL_CNT, the value in REG_TCC is an address,
                 * push tcc_ptr into stack
                 */
                emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_SP, *store_offset);
        } else {
                *store_offset -= sizeof(long);
                emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_SP, *store_offset);
        }

        /* Push tcc_ptr into stack */
        *store_offset -= sizeof(long);
        emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_SP, *store_offset);
}

/*
 * eBPF prog stack layout:
 *
 *                                        high
 * original $sp ------------> +-------------------------+ <--LOONGARCH_GPR_FP
 *                            |           $ra           |
 *                            +-------------------------+
 *                            |           $fp           |
 *                            +-------------------------+
 *                            |           $s0           |
 *                            +-------------------------+
 *                            |           $s1           |
 *                            +-------------------------+
 *                            |           $s2           |
 *                            +-------------------------+
 *                            |           $s3           |
 *                            +-------------------------+
 *                            |           $s4           |
 *                            +-------------------------+
 *                            |           $s5           |
 *                            +-------------------------+
 *                            |           tcc           |
 *                            +-------------------------+
 *                            |           tcc_ptr       |
 *                            +-------------------------+ <--BPF_REG_FP
 *                            |  prog->aux->stack_depth |
 *                            |        (optional)       |
 * current $sp -------------> +-------------------------+
 *                                        low
 */
static void build_prologue(struct jit_ctx *ctx)
{
        int i, stack_adjust = 0, store_offset, bpf_stack_adjust;
        const struct bpf_prog *prog = ctx->prog;
        const bool is_main_prog = !bpf_is_subprog(prog);

        bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16);

        /* To store ra, fp, s0, s1, s2, s3, s4, s5 */
        stack_adjust += sizeof(long) * 8;

        /* To store tcc and tcc_ptr */
        stack_adjust += sizeof(long) * 2;

        if (ctx->arena_vm_start)
                stack_adjust += 8;

        stack_adjust = round_up(stack_adjust, 16);
        stack_adjust += bpf_stack_adjust;

        move_reg(ctx, LOONGARCH_GPR_T0, LOONGARCH_GPR_RA);
        /* Reserve space for the move_imm + jirl instruction */
        for (i = 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++)
                emit_insn(ctx, nop);

        /*
         * First instruction initializes the tail call count (TCC)
         * register to zero. On tail call we skip this instruction,
         * and the TCC is passed in REG_TCC from the caller.
         */
        if (is_main_prog)
                emit_insn(ctx, addid, REG_TCC, LOONGARCH_GPR_ZERO, 0);

        emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_adjust);

        store_offset = stack_adjust - sizeof(long);
        emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, store_offset);

        store_offset -= sizeof(long);
        emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, store_offset);

        store_offset -= sizeof(long);
        emit_insn(ctx, std, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, store_offset);

        store_offset -= sizeof(long);
        emit_insn(ctx, std, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, store_offset);

        store_offset -= sizeof(long);
        emit_insn(ctx, std, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, store_offset);

        store_offset -= sizeof(long);
        emit_insn(ctx, std, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, store_offset);

        store_offset -= sizeof(long);
        emit_insn(ctx, std, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, store_offset);

        store_offset -= sizeof(long);
        emit_insn(ctx, std, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, store_offset);

        if (ctx->arena_vm_start) {
                store_offset -= sizeof(long);
                emit_insn(ctx, std, REG_ARENA, LOONGARCH_GPR_SP, store_offset);
        }

        prepare_bpf_tail_call_cnt(ctx, &store_offset);

        emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_adjust);

        if (bpf_stack_adjust)
                emit_insn(ctx, addid, regmap[BPF_REG_FP], LOONGARCH_GPR_SP, bpf_stack_adjust);

        ctx->stack_size = stack_adjust;

        if (ctx->arena_vm_start)
                move_imm(ctx, REG_ARENA, ctx->arena_vm_start, false);
}

static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call)
{
        int stack_adjust = ctx->stack_size;
        int load_offset;

        load_offset = stack_adjust - sizeof(long);
        emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, load_offset);

        load_offset -= sizeof(long);
        emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, load_offset);

        load_offset -= sizeof(long);
        emit_insn(ctx, ldd, LOONGARCH_GPR_S0, LOONGARCH_GPR_SP, load_offset);

        load_offset -= sizeof(long);
        emit_insn(ctx, ldd, LOONGARCH_GPR_S1, LOONGARCH_GPR_SP, load_offset);

        load_offset -= sizeof(long);
        emit_insn(ctx, ldd, LOONGARCH_GPR_S2, LOONGARCH_GPR_SP, load_offset);

        load_offset -= sizeof(long);
        emit_insn(ctx, ldd, LOONGARCH_GPR_S3, LOONGARCH_GPR_SP, load_offset);

        load_offset -= sizeof(long);
        emit_insn(ctx, ldd, LOONGARCH_GPR_S4, LOONGARCH_GPR_SP, load_offset);

        load_offset -= sizeof(long);
        emit_insn(ctx, ldd, LOONGARCH_GPR_S5, LOONGARCH_GPR_SP, load_offset);

        if (ctx->arena_vm_start) {
                load_offset -= sizeof(long);
                emit_insn(ctx, ldd, REG_ARENA, LOONGARCH_GPR_SP, load_offset);
        }

        /*
         * When push into the stack, follow the order of tcc then tcc_ptr.
         * When pop from the stack, first pop tcc_ptr then followed by tcc.
         */
        load_offset -= 2 * sizeof(long);
        emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_SP, load_offset);

        load_offset += sizeof(long);
        emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_SP, load_offset);

        emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_adjust);

        if (!is_tail_call) {
                /* Set return value */
                emit_insn(ctx, addiw, LOONGARCH_GPR_A0, regmap[BPF_REG_0], 0);
                /* Return to the caller */
                emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_RA, 0);
        } else {
                /*
                 * Call the next bpf prog and skip the first instruction
                 * of TCC initialization.
                 */
                emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T3, 7);
        }
}

static void build_epilogue(struct jit_ctx *ctx)
{
        __build_epilogue(ctx, false);
}

bool bpf_jit_supports_kfunc_call(void)
{
        return true;
}

bool bpf_jit_supports_far_kfunc_call(void)
{
        return true;
}

static int emit_bpf_tail_call(struct jit_ctx *ctx, int insn)
{
        int off, tc_ninsn = 0;
        int tcc_ptr_off = BPF_TAIL_CALL_CNT_PTR_STACK_OFF(ctx->stack_size);
        u8 a1 = LOONGARCH_GPR_A1;
        u8 a2 = LOONGARCH_GPR_A2;
        u8 t1 = LOONGARCH_GPR_T1;
        u8 t2 = LOONGARCH_GPR_T2;
        u8 t3 = LOONGARCH_GPR_T3;
        const int idx0 = ctx->idx;

#define cur_offset (ctx->idx - idx0)
#define jmp_offset (tc_ninsn - (cur_offset))

        /*
         * a0: &ctx
         * a1: &array
         * a2: index
         *
         * if (index >= array->map.max_entries)
         *       goto out;
         */
        tc_ninsn = insn ? ctx->offset[insn+1] - ctx->offset[insn] : ctx->offset[0];
        emit_zext_32(ctx, a2, true);

        off = offsetof(struct bpf_array, map.max_entries);
        emit_insn(ctx, ldwu, t1, a1, off);
        /* bgeu $a2, $t1, jmp_offset */
        if (emit_tailcall_jmp(ctx, BPF_JGE, a2, t1, jmp_offset) < 0)
                goto toofar;

        /*
         * if ((*tcc_ptr)++ >= MAX_TAIL_CALL_CNT)
         *      goto out;
         */
        emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_SP, tcc_ptr_off);
        emit_insn(ctx, ldd, t3, REG_TCC, 0);
        emit_insn(ctx, addid, t3, t3, 1);
        emit_insn(ctx, std, t3, REG_TCC, 0);
        emit_insn(ctx, addid, t2, LOONGARCH_GPR_ZERO, MAX_TAIL_CALL_CNT);
        if (emit_tailcall_jmp(ctx, BPF_JSGT, t3, t2, jmp_offset) < 0)
                goto toofar;

        /*
         * prog = array->ptrs[index];
         * if (!prog)
         *       goto out;
         */
        emit_insn(ctx, alsld, t2, a2, a1, 2);
        off = offsetof(struct bpf_array, ptrs);
        emit_insn(ctx, ldd, t2, t2, off);
        /* beq $t2, $zero, jmp_offset */
        if (emit_tailcall_jmp(ctx, BPF_JEQ, t2, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
                goto toofar;

        /* goto *(prog->bpf_func + 4); */
        off = offsetof(struct bpf_prog, bpf_func);
        emit_insn(ctx, ldd, t3, t2, off);
        __build_epilogue(ctx, true);

        return 0;

toofar:
        pr_info_once("tail_call: jump too far\n");
        return -1;
#undef cur_offset
#undef jmp_offset
}

static void emit_atomic(const struct bpf_insn *insn, struct jit_ctx *ctx)
{
        const u8 t1 = LOONGARCH_GPR_T1;
        const u8 t2 = LOONGARCH_GPR_T2;
        const u8 t3 = LOONGARCH_GPR_T3;
        const u8 r0 = regmap[BPF_REG_0];
        const u8 src = regmap[insn->src_reg];
        const u8 dst = regmap[insn->dst_reg];
        const s16 off = insn->off;
        const s32 imm = insn->imm;
        const bool isdw = BPF_SIZE(insn->code) == BPF_DW;

        move_imm(ctx, t1, off, false);
        emit_insn(ctx, addd, t1, dst, t1);
        move_reg(ctx, t3, src);

        switch (imm) {
        /* lock *(size *)(dst + off) <op>= src */
        case BPF_ADD:
                if (isdw)
                        emit_insn(ctx, amaddd, t2, t1, src);
                else
                        emit_insn(ctx, amaddw, t2, t1, src);
                break;
        case BPF_AND:
                if (isdw)
                        emit_insn(ctx, amandd, t2, t1, src);
                else
                        emit_insn(ctx, amandw, t2, t1, src);
                break;
        case BPF_OR:
                if (isdw)
                        emit_insn(ctx, amord, t2, t1, src);
                else
                        emit_insn(ctx, amorw, t2, t1, src);
                break;
        case BPF_XOR:
                if (isdw)
                        emit_insn(ctx, amxord, t2, t1, src);
                else
                        emit_insn(ctx, amxorw, t2, t1, src);
                break;
        /* src = atomic_fetch_<op>(dst + off, src) */
        case BPF_ADD | BPF_FETCH:
                if (isdw) {
                        emit_insn(ctx, amaddd, src, t1, t3);
                } else {
                        emit_insn(ctx, amaddw, src, t1, t3);
                        emit_zext_32(ctx, src, true);
                }
                break;
        case BPF_AND | BPF_FETCH:
                if (isdw) {
                        emit_insn(ctx, amandd, src, t1, t3);
                } else {
                        emit_insn(ctx, amandw, src, t1, t3);
                        emit_zext_32(ctx, src, true);
                }
                break;
        case BPF_OR | BPF_FETCH:
                if (isdw) {
                        emit_insn(ctx, amord, src, t1, t3);
                } else {
                        emit_insn(ctx, amorw, src, t1, t3);
                        emit_zext_32(ctx, src, true);
                }
                break;
        case BPF_XOR | BPF_FETCH:
                if (isdw) {
                        emit_insn(ctx, amxord, src, t1, t3);
                } else {
                        emit_insn(ctx, amxorw, src, t1, t3);
                        emit_zext_32(ctx, src, true);
                }
                break;
        /* src = atomic_xchg(dst + off, src); */
        case BPF_XCHG:
                if (isdw) {
                        emit_insn(ctx, amswapd, src, t1, t3);
                } else {
                        emit_insn(ctx, amswapw, src, t1, t3);
                        emit_zext_32(ctx, src, true);
                }
                break;
        /* r0 = atomic_cmpxchg(dst + off, r0, src); */
        case BPF_CMPXCHG:
                move_reg(ctx, t2, r0);
                if (isdw) {
                        emit_insn(ctx, lld, r0, t1, 0);
                        emit_insn(ctx, bne, t2, r0, 4);
                        move_reg(ctx, t3, src);
                        emit_insn(ctx, scd, t3, t1, 0);
                        emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -4);
                } else {
                        emit_insn(ctx, llw, r0, t1, 0);
                        emit_zext_32(ctx, t2, true);
                        emit_zext_32(ctx, r0, true);
                        emit_insn(ctx, bne, t2, r0, 4);
                        move_reg(ctx, t3, src);
                        emit_insn(ctx, scw, t3, t1, 0);
                        emit_insn(ctx, beq, t3, LOONGARCH_GPR_ZERO, -6);
                        emit_zext_32(ctx, r0, true);
                }
                break;
        }
}

static bool is_signed_bpf_cond(u8 cond)
{
        return cond == BPF_JSGT || cond == BPF_JSLT ||
               cond == BPF_JSGE || cond == BPF_JSLE;
}

#define BPF_FIXUP_REG_MASK      GENMASK(31, 27)
#define BPF_FIXUP_OFFSET_MASK   GENMASK(26, 0)
#define REG_DONT_CLEAR_MARKER   0

bool ex_handler_bpf(const struct exception_table_entry *ex,
                    struct pt_regs *regs)
{
        int dst_reg = FIELD_GET(BPF_FIXUP_REG_MASK, ex->fixup);
        off_t offset = FIELD_GET(BPF_FIXUP_OFFSET_MASK, ex->fixup);

        if (dst_reg != REG_DONT_CLEAR_MARKER)
                regs->regs[dst_reg] = 0;
        regs->csr_era = (unsigned long)&ex->fixup - offset;

        return true;
}

/* For accesses to BTF pointers, add an entry to the exception table */
static int add_exception_handler(const struct bpf_insn *insn,
                                 struct jit_ctx *ctx,
                                 int dst_reg)
{
        unsigned long pc;
        off_t ins_offset, fixup_offset;
        struct exception_table_entry *ex;

        if (!ctx->image || !ctx->ro_image || !ctx->prog->aux->extable)
                return 0;

        if (BPF_MODE(insn->code) != BPF_PROBE_MEM &&
            BPF_MODE(insn->code) != BPF_PROBE_MEMSX &&
            BPF_MODE(insn->code) != BPF_PROBE_MEM32)
                return 0;

        if (WARN_ON_ONCE(ctx->num_exentries >= ctx->prog->aux->num_exentries))
                return -EINVAL;

        ex = &ctx->prog->aux->extable[ctx->num_exentries];
        pc = (unsigned long)&ctx->ro_image[ctx->idx - 1];

        /*
         * This is the relative offset of the instruction that may fault from
         * the exception table itself. This will be written to the exception
         * table and if this instruction faults, the destination register will
         * be set to '0' and the execution will jump to the next instruction.
         */
        ins_offset = pc - (long)&ex->insn;
        if (WARN_ON_ONCE(ins_offset >= 0 || ins_offset < INT_MIN))
                return -ERANGE;

        /*
         * Since the extable follows the program, the fixup offset is always
         * negative and limited to BPF_JIT_REGION_SIZE. Store a positive value
         * to keep things simple, and put the destination register in the upper
         * bits. We don't need to worry about buildtime or runtime sort
         * modifying the upper bits because the table is already sorted, and
         * isn't part of the main exception table.
         *
         * The fixup_offset is set to the next instruction from the instruction
         * that may fault. The execution will jump to this after handling the fault.
         */
        fixup_offset = (long)&ex->fixup - (pc + LOONGARCH_INSN_SIZE);
        if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, fixup_offset))
                return -ERANGE;

        /*
         * The offsets above have been calculated using the RO buffer but we
         * need to use the R/W buffer for writes. Switch ex to rw buffer for writing.
         */
        ex = (void *)ctx->image + ((void *)ex - (void *)ctx->ro_image);
        ex->insn = ins_offset;
        ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, fixup_offset) |
                    FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg);
        ex->type = EX_TYPE_BPF;

        ctx->num_exentries++;

        return 0;
}

static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool extra_pass)
{
        u8 tm = -1;
        u64 func_addr;
        bool func_addr_fixed, sign_extend;
        int i = insn - ctx->prog->insnsi;
        int ret, jmp_offset, tcc_ptr_off;
        const u8 code = insn->code;
        const u8 cond = BPF_OP(code);
        const u8 t1 = LOONGARCH_GPR_T1;
        const u8 t2 = LOONGARCH_GPR_T2;
        const u8 t3 = LOONGARCH_GPR_T3;
        u8 src = regmap[insn->src_reg];
        u8 dst = regmap[insn->dst_reg];
        const s16 off = insn->off;
        const s32 imm = insn->imm;
        const bool is32 = BPF_CLASS(insn->code) == BPF_ALU || BPF_CLASS(insn->code) == BPF_JMP32;

        switch (code) {
        /* dst = src */
        case BPF_ALU | BPF_MOV | BPF_X:
        case BPF_ALU64 | BPF_MOV | BPF_X:
                if (insn_is_cast_user(insn)) {
                        move_reg(ctx, t1, src);
                        emit_zext_32(ctx, t1, true);
                        move_imm(ctx, dst, (ctx->user_vm_start >> 32) << 32, false);
                        emit_insn(ctx, beq, t1, LOONGARCH_GPR_ZERO, 1);
                        emit_insn(ctx, or, t1, dst, t1);
                        move_reg(ctx, dst, t1);
                        break;
                }
                switch (off) {
                case 0:
                        move_reg(ctx, dst, src);
                        emit_zext_32(ctx, dst, is32);
                        break;
                case 8:
                        emit_insn(ctx, extwb, dst, src);
                        emit_zext_32(ctx, dst, is32);
                        break;
                case 16:
                        emit_insn(ctx, extwh, dst, src);
                        emit_zext_32(ctx, dst, is32);
                        break;
                case 32:
                        emit_insn(ctx, addw, dst, src, LOONGARCH_GPR_ZERO);
                        break;
                }
                break;

        /* dst = imm */
        case BPF_ALU | BPF_MOV | BPF_K:
        case BPF_ALU64 | BPF_MOV | BPF_K:
                move_imm(ctx, dst, imm, is32);
                break;

        /* dst = dst + src */
        case BPF_ALU | BPF_ADD | BPF_X:
        case BPF_ALU64 | BPF_ADD | BPF_X:
                emit_insn(ctx, addd, dst, dst, src);
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst + imm */
        case BPF_ALU | BPF_ADD | BPF_K:
        case BPF_ALU64 | BPF_ADD | BPF_K:
                if (is_signed_imm12(imm)) {
                        emit_insn(ctx, addid, dst, dst, imm);
                } else {
                        move_imm(ctx, t1, imm, is32);
                        emit_insn(ctx, addd, dst, dst, t1);
                }
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst - src */
        case BPF_ALU | BPF_SUB | BPF_X:
        case BPF_ALU64 | BPF_SUB | BPF_X:
                emit_insn(ctx, subd, dst, dst, src);
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst - imm */
        case BPF_ALU | BPF_SUB | BPF_K:
        case BPF_ALU64 | BPF_SUB | BPF_K:
                if (is_signed_imm12(-imm)) {
                        emit_insn(ctx, addid, dst, dst, -imm);
                } else {
                        move_imm(ctx, t1, imm, is32);
                        emit_insn(ctx, subd, dst, dst, t1);
                }
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst * src */
        case BPF_ALU | BPF_MUL | BPF_X:
        case BPF_ALU64 | BPF_MUL | BPF_X:
                emit_insn(ctx, muld, dst, dst, src);
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst * imm */
        case BPF_ALU | BPF_MUL | BPF_K:
        case BPF_ALU64 | BPF_MUL | BPF_K:
                move_imm(ctx, t1, imm, is32);
                emit_insn(ctx, muld, dst, dst, t1);
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst / src */
        case BPF_ALU | BPF_DIV | BPF_X:
        case BPF_ALU64 | BPF_DIV | BPF_X:
                if (!off) {
                        emit_zext_32(ctx, dst, is32);
                        move_reg(ctx, t1, src);
                        emit_zext_32(ctx, t1, is32);
                        emit_insn(ctx, divdu, dst, dst, t1);
                        emit_zext_32(ctx, dst, is32);
                } else {
                        emit_sext_32(ctx, dst, is32);
                        move_reg(ctx, t1, src);
                        emit_sext_32(ctx, t1, is32);
                        emit_insn(ctx, divd, dst, dst, t1);
                        emit_sext_32(ctx, dst, is32);
                }
                break;

        /* dst = dst / imm */
        case BPF_ALU | BPF_DIV | BPF_K:
        case BPF_ALU64 | BPF_DIV | BPF_K:
                if (!off) {
                        move_imm(ctx, t1, imm, is32);
                        emit_zext_32(ctx, dst, is32);
                        emit_insn(ctx, divdu, dst, dst, t1);
                        emit_zext_32(ctx, dst, is32);
                } else {
                        move_imm(ctx, t1, imm, false);
                        emit_sext_32(ctx, t1, is32);
                        emit_sext_32(ctx, dst, is32);
                        emit_insn(ctx, divd, dst, dst, t1);
                        emit_sext_32(ctx, dst, is32);
                }
                break;

        /* dst = dst % src */
        case BPF_ALU | BPF_MOD | BPF_X:
        case BPF_ALU64 | BPF_MOD | BPF_X:
                if (!off) {
                        emit_zext_32(ctx, dst, is32);
                        move_reg(ctx, t1, src);
                        emit_zext_32(ctx, t1, is32);
                        emit_insn(ctx, moddu, dst, dst, t1);
                        emit_zext_32(ctx, dst, is32);
                } else {
                        emit_sext_32(ctx, dst, is32);
                        move_reg(ctx, t1, src);
                        emit_sext_32(ctx, t1, is32);
                        emit_insn(ctx, modd, dst, dst, t1);
                        emit_sext_32(ctx, dst, is32);
                }
                break;

        /* dst = dst % imm */
        case BPF_ALU | BPF_MOD | BPF_K:
        case BPF_ALU64 | BPF_MOD | BPF_K:
                if (!off) {
                        move_imm(ctx, t1, imm, is32);
                        emit_zext_32(ctx, dst, is32);
                        emit_insn(ctx, moddu, dst, dst, t1);
                        emit_zext_32(ctx, dst, is32);
                } else {
                        move_imm(ctx, t1, imm, false);
                        emit_sext_32(ctx, t1, is32);
                        emit_sext_32(ctx, dst, is32);
                        emit_insn(ctx, modd, dst, dst, t1);
                        emit_sext_32(ctx, dst, is32);
                }
                break;

        /* dst = -dst */
        case BPF_ALU | BPF_NEG:
        case BPF_ALU64 | BPF_NEG:
                move_imm(ctx, t1, imm, is32);
                emit_insn(ctx, subd, dst, LOONGARCH_GPR_ZERO, dst);
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst & src */
        case BPF_ALU | BPF_AND | BPF_X:
        case BPF_ALU64 | BPF_AND | BPF_X:
                emit_insn(ctx, and, dst, dst, src);
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst & imm */
        case BPF_ALU | BPF_AND | BPF_K:
        case BPF_ALU64 | BPF_AND | BPF_K:
                if (is_unsigned_imm12(imm)) {
                        emit_insn(ctx, andi, dst, dst, imm);
                } else {
                        move_imm(ctx, t1, imm, is32);
                        emit_insn(ctx, and, dst, dst, t1);
                }
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst | src */
        case BPF_ALU | BPF_OR | BPF_X:
        case BPF_ALU64 | BPF_OR | BPF_X:
                emit_insn(ctx, or, dst, dst, src);
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst | imm */
        case BPF_ALU | BPF_OR | BPF_K:
        case BPF_ALU64 | BPF_OR | BPF_K:
                if (is_unsigned_imm12(imm)) {
                        emit_insn(ctx, ori, dst, dst, imm);
                } else {
                        move_imm(ctx, t1, imm, is32);
                        emit_insn(ctx, or, dst, dst, t1);
                }
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst ^ src */
        case BPF_ALU | BPF_XOR | BPF_X:
        case BPF_ALU64 | BPF_XOR | BPF_X:
                emit_insn(ctx, xor, dst, dst, src);
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst ^ imm */
        case BPF_ALU | BPF_XOR | BPF_K:
        case BPF_ALU64 | BPF_XOR | BPF_K:
                if (is_unsigned_imm12(imm)) {
                        emit_insn(ctx, xori, dst, dst, imm);
                } else {
                        move_imm(ctx, t1, imm, is32);
                        emit_insn(ctx, xor, dst, dst, t1);
                }
                emit_zext_32(ctx, dst, is32);
                break;

        /* dst = dst << src (logical) */
        case BPF_ALU | BPF_LSH | BPF_X:
                emit_insn(ctx, sllw, dst, dst, src);
                emit_zext_32(ctx, dst, is32);
                break;

        case BPF_ALU64 | BPF_LSH | BPF_X:
                emit_insn(ctx, slld, dst, dst, src);
                break;

        /* dst = dst << imm (logical) */
        case BPF_ALU | BPF_LSH | BPF_K:
                emit_insn(ctx, slliw, dst, dst, imm);
                emit_zext_32(ctx, dst, is32);
                break;

        case BPF_ALU64 | BPF_LSH | BPF_K:
                emit_insn(ctx, sllid, dst, dst, imm);
                break;

        /* dst = dst >> src (logical) */
        case BPF_ALU | BPF_RSH | BPF_X:
                emit_insn(ctx, srlw, dst, dst, src);
                emit_zext_32(ctx, dst, is32);
                break;

        case BPF_ALU64 | BPF_RSH | BPF_X:
                emit_insn(ctx, srld, dst, dst, src);
                break;

        /* dst = dst >> imm (logical) */
        case BPF_ALU | BPF_RSH | BPF_K:
                emit_insn(ctx, srliw, dst, dst, imm);
                emit_zext_32(ctx, dst, is32);
                break;

        case BPF_ALU64 | BPF_RSH | BPF_K:
                emit_insn(ctx, srlid, dst, dst, imm);
                break;

        /* dst = dst >> src (arithmetic) */
        case BPF_ALU | BPF_ARSH | BPF_X:
                emit_insn(ctx, sraw, dst, dst, src);
                emit_zext_32(ctx, dst, is32);
                break;

        case BPF_ALU64 | BPF_ARSH | BPF_X:
                emit_insn(ctx, srad, dst, dst, src);
                break;

        /* dst = dst >> imm (arithmetic) */
        case BPF_ALU | BPF_ARSH | BPF_K:
                emit_insn(ctx, sraiw, dst, dst, imm);
                emit_zext_32(ctx, dst, is32);
                break;

        case BPF_ALU64 | BPF_ARSH | BPF_K:
                emit_insn(ctx, sraid, dst, dst, imm);
                break;

        /* dst = BSWAP##imm(dst) */
        case BPF_ALU | BPF_END | BPF_FROM_LE:
                switch (imm) {
                case 16:
                        /* zero-extend 16 bits into 64 bits */
                        emit_insn(ctx, bstrpickd, dst, dst, 15, 0);
                        break;
                case 32:
                        /* zero-extend 32 bits into 64 bits */
                        emit_zext_32(ctx, dst, is32);
                        break;
                case 64:
                        /* do nothing */
                        break;
                }
                break;

        case BPF_ALU | BPF_END | BPF_FROM_BE:
        case BPF_ALU64 | BPF_END | BPF_FROM_LE:
                switch (imm) {
                case 16:
                        emit_insn(ctx, revb2h, dst, dst);
                        /* zero-extend 16 bits into 64 bits */
                        emit_insn(ctx, bstrpickd, dst, dst, 15, 0);
                        break;
                case 32:
                        emit_insn(ctx, revb2w, dst, dst);
                        /* clear the upper 32 bits */
                        emit_zext_32(ctx, dst, true);
                        break;
                case 64:
                        emit_insn(ctx, revbd, dst, dst);
                        break;
                }
                break;

        /* PC += off if dst cond src */
        case BPF_JMP | BPF_JEQ | BPF_X:
        case BPF_JMP | BPF_JNE | BPF_X:
        case BPF_JMP | BPF_JGT | BPF_X:
        case BPF_JMP | BPF_JGE | BPF_X:
        case BPF_JMP | BPF_JLT | BPF_X:
        case BPF_JMP | BPF_JLE | BPF_X:
        case BPF_JMP | BPF_JSGT | BPF_X:
        case BPF_JMP | BPF_JSGE | BPF_X:
        case BPF_JMP | BPF_JSLT | BPF_X:
        case BPF_JMP | BPF_JSLE | BPF_X:
        case BPF_JMP32 | BPF_JEQ | BPF_X:
        case BPF_JMP32 | BPF_JNE | BPF_X:
        case BPF_JMP32 | BPF_JGT | BPF_X:
        case BPF_JMP32 | BPF_JGE | BPF_X:
        case BPF_JMP32 | BPF_JLT | BPF_X:
        case BPF_JMP32 | BPF_JLE | BPF_X:
        case BPF_JMP32 | BPF_JSGT | BPF_X:
        case BPF_JMP32 | BPF_JSGE | BPF_X:
        case BPF_JMP32 | BPF_JSLT | BPF_X:
        case BPF_JMP32 | BPF_JSLE | BPF_X:
                jmp_offset = bpf2la_offset(i, off, ctx);
                move_reg(ctx, t1, dst);
                move_reg(ctx, t2, src);
                if (is_signed_bpf_cond(BPF_OP(code))) {
                        emit_sext_32(ctx, t1, is32);
                        emit_sext_32(ctx, t2, is32);
                } else {
                        emit_zext_32(ctx, t1, is32);
                        emit_zext_32(ctx, t2, is32);
                }
                if (emit_cond_jmp(ctx, cond, t1, t2, jmp_offset) < 0)
                        goto toofar;
                break;

        /* PC += off if dst cond imm */
        case BPF_JMP | BPF_JEQ | BPF_K:
        case BPF_JMP | BPF_JNE | BPF_K:
        case BPF_JMP | BPF_JGT | BPF_K:
        case BPF_JMP | BPF_JGE | BPF_K:
        case BPF_JMP | BPF_JLT | BPF_K:
        case BPF_JMP | BPF_JLE | BPF_K:
        case BPF_JMP | BPF_JSGT | BPF_K:
        case BPF_JMP | BPF_JSGE | BPF_K:
        case BPF_JMP | BPF_JSLT | BPF_K:
        case BPF_JMP | BPF_JSLE | BPF_K:
        case BPF_JMP32 | BPF_JEQ | BPF_K:
        case BPF_JMP32 | BPF_JNE | BPF_K:
        case BPF_JMP32 | BPF_JGT | BPF_K:
        case BPF_JMP32 | BPF_JGE | BPF_K:
        case BPF_JMP32 | BPF_JLT | BPF_K:
        case BPF_JMP32 | BPF_JLE | BPF_K:
        case BPF_JMP32 | BPF_JSGT | BPF_K:
        case BPF_JMP32 | BPF_JSGE | BPF_K:
        case BPF_JMP32 | BPF_JSLT | BPF_K:
        case BPF_JMP32 | BPF_JSLE | BPF_K:
                jmp_offset = bpf2la_offset(i, off, ctx);
                if (imm) {
                        move_imm(ctx, t1, imm, false);
                        tm = t1;
                } else {
                        /* If imm is 0, simply use zero register. */
                        tm = LOONGARCH_GPR_ZERO;
                }
                move_reg(ctx, t2, dst);
                if (is_signed_bpf_cond(BPF_OP(code))) {
                        emit_sext_32(ctx, tm, is32);
                        emit_sext_32(ctx, t2, is32);
                } else {
                        emit_zext_32(ctx, tm, is32);
                        emit_zext_32(ctx, t2, is32);
                }
                if (emit_cond_jmp(ctx, cond, t2, tm, jmp_offset) < 0)
                        goto toofar;
                break;

        /* PC += off if dst & src */
        case BPF_JMP | BPF_JSET | BPF_X:
        case BPF_JMP32 | BPF_JSET | BPF_X:
                jmp_offset = bpf2la_offset(i, off, ctx);
                emit_insn(ctx, and, t1, dst, src);
                emit_zext_32(ctx, t1, is32);
                if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
                        goto toofar;
                break;

        /* PC += off if dst & imm */
        case BPF_JMP | BPF_JSET | BPF_K:
        case BPF_JMP32 | BPF_JSET | BPF_K:
                jmp_offset = bpf2la_offset(i, off, ctx);
                move_imm(ctx, t1, imm, is32);
                emit_insn(ctx, and, t1, dst, t1);
                emit_zext_32(ctx, t1, is32);
                if (emit_cond_jmp(ctx, cond, t1, LOONGARCH_GPR_ZERO, jmp_offset) < 0)
                        goto toofar;
                break;

        /* PC += off */
        case BPF_JMP | BPF_JA:
        case BPF_JMP32 | BPF_JA:
                if (BPF_CLASS(code) == BPF_JMP)
                        jmp_offset = bpf2la_offset(i, off, ctx);
                else
                        jmp_offset = bpf2la_offset(i, imm, ctx);
                if (emit_uncond_jmp(ctx, jmp_offset) < 0)
                        goto toofar;
                break;

        /* function call */
        case BPF_JMP | BPF_CALL:
                ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass,
                                            &func_addr, &func_addr_fixed);
                if (ret < 0)
                        return ret;

                if (insn->src_reg == BPF_PSEUDO_CALL) {
                        tcc_ptr_off = BPF_TAIL_CALL_CNT_PTR_STACK_OFF(ctx->stack_size);
                        emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_SP, tcc_ptr_off);
                }

                if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) {
                        const struct btf_func_model *m;
                        int i;

                        m = bpf_jit_find_kfunc_model(ctx->prog, insn);
                        if (!m)
                                return -EINVAL;

                        for (i = 0; i < m->nr_args; i++) {
                                u8 reg = regmap[BPF_REG_1 + i];
                                bool sign = m->arg_flags[i] & BTF_FMODEL_SIGNED_ARG;

                                emit_abi_ext(ctx, reg, m->arg_size[i], sign);
                        }
                }

                move_addr(ctx, t1, func_addr);
                emit_insn(ctx, jirl, LOONGARCH_GPR_RA, t1, 0);

                if (insn->src_reg != BPF_PSEUDO_CALL)
                        move_reg(ctx, regmap[BPF_REG_0], LOONGARCH_GPR_A0);

                break;

        /* tail call */
        case BPF_JMP | BPF_TAIL_CALL:
                if (emit_bpf_tail_call(ctx, i) < 0)
                        return -EINVAL;
                break;

        /* function return */
        case BPF_JMP | BPF_EXIT:
                if (i == ctx->prog->len - 1)
                        break;

                jmp_offset = epilogue_offset(ctx);
                if (emit_uncond_jmp(ctx, jmp_offset) < 0)
                        goto toofar;
                break;

        /* dst = imm64 */
        case BPF_LD | BPF_IMM | BPF_DW:
        {
                const u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm;

                if (bpf_pseudo_func(insn))
                        move_addr(ctx, dst, imm64);
                else
                        move_imm(ctx, dst, imm64, is32);
                return 1;
        }

        /* dst = *(size *)(src + off) */
        case BPF_LDX | BPF_MEM | BPF_B:
        case BPF_LDX | BPF_MEM | BPF_H:
        case BPF_LDX | BPF_MEM | BPF_W:
        case BPF_LDX | BPF_MEM | BPF_DW:
        case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
        case BPF_LDX | BPF_PROBE_MEM | BPF_W:
        case BPF_LDX | BPF_PROBE_MEM | BPF_H:
        case BPF_LDX | BPF_PROBE_MEM | BPF_B:
        /* dst_reg = (s64)*(signed size *)(src_reg + off) */
        case BPF_LDX | BPF_MEMSX | BPF_B:
        case BPF_LDX | BPF_MEMSX | BPF_H:
        case BPF_LDX | BPF_MEMSX | BPF_W:
        case BPF_LDX | BPF_PROBE_MEMSX | BPF_B:
        case BPF_LDX | BPF_PROBE_MEMSX | BPF_H:
        case BPF_LDX | BPF_PROBE_MEMSX | BPF_W:
        /* LDX | PROBE_MEM32: dst = *(unsigned size *)(src + REG_ARENA + off) */
        case BPF_LDX | BPF_PROBE_MEM32 | BPF_B:
        case BPF_LDX | BPF_PROBE_MEM32 | BPF_H:
        case BPF_LDX | BPF_PROBE_MEM32 | BPF_W:
        case BPF_LDX | BPF_PROBE_MEM32 | BPF_DW:
                sign_extend = BPF_MODE(code) == BPF_MEMSX ||
                              BPF_MODE(code) == BPF_PROBE_MEMSX;

                if (BPF_MODE(code) == BPF_PROBE_MEM32) {
                        emit_insn(ctx, addd, t2, src, REG_ARENA);
                        src = t2;
                }

                switch (BPF_SIZE(code)) {
                case BPF_B:
                        if (is_signed_imm12(off)) {
                                if (sign_extend)
                                        emit_insn(ctx, ldb, dst, src, off);
                                else
                                        emit_insn(ctx, ldbu, dst, src, off);
                        } else {
                                move_imm(ctx, t1, off, is32);
                                if (sign_extend)
                                        emit_insn(ctx, ldxb, dst, src, t1);
                                else
                                        emit_insn(ctx, ldxbu, dst, src, t1);
                        }
                        break;
                case BPF_H:
                        if (is_signed_imm12(off)) {
                                if (sign_extend)
                                        emit_insn(ctx, ldh, dst, src, off);
                                else
                                        emit_insn(ctx, ldhu, dst, src, off);
                        } else {
                                move_imm(ctx, t1, off, is32);
                                if (sign_extend)
                                        emit_insn(ctx, ldxh, dst, src, t1);
                                else
                                        emit_insn(ctx, ldxhu, dst, src, t1);
                        }
                        break;
                case BPF_W:
                        if (is_signed_imm12(off)) {
                                if (sign_extend)
                                        emit_insn(ctx, ldw, dst, src, off);
                                else
                                        emit_insn(ctx, ldwu, dst, src, off);
                        } else {
                                move_imm(ctx, t1, off, is32);
                                if (sign_extend)
                                        emit_insn(ctx, ldxw, dst, src, t1);
                                else
                                        emit_insn(ctx, ldxwu, dst, src, t1);
                        }
                        break;
                case BPF_DW:
                        move_imm(ctx, t1, off, is32);
                        emit_insn(ctx, ldxd, dst, src, t1);
                        break;
                }

                ret = add_exception_handler(insn, ctx, dst);
                if (ret)
                        return ret;
                break;

        /* *(size *)(dst + off) = imm */
        case BPF_ST | BPF_MEM | BPF_B:
        case BPF_ST | BPF_MEM | BPF_H:
        case BPF_ST | BPF_MEM | BPF_W:
        case BPF_ST | BPF_MEM | BPF_DW:
        /* ST | PROBE_MEM32: *(size *)(dst + REG_ARENA + off) = imm */
        case BPF_ST | BPF_PROBE_MEM32 | BPF_B:
        case BPF_ST | BPF_PROBE_MEM32 | BPF_H:
        case BPF_ST | BPF_PROBE_MEM32 | BPF_W:
        case BPF_ST | BPF_PROBE_MEM32 | BPF_DW:
                if (BPF_MODE(code) == BPF_PROBE_MEM32) {
                        emit_insn(ctx, addd, t3, dst, REG_ARENA);
                        dst = t3;
                }

                switch (BPF_SIZE(code)) {
                case BPF_B:
                        move_imm(ctx, t1, imm, is32);
                        if (is_signed_imm12(off)) {
                                emit_insn(ctx, stb, t1, dst, off);
                        } else {
                                move_imm(ctx, t2, off, is32);
                                emit_insn(ctx, stxb, t1, dst, t2);
                        }
                        break;
                case BPF_H:
                        move_imm(ctx, t1, imm, is32);
                        if (is_signed_imm12(off)) {
                                emit_insn(ctx, sth, t1, dst, off);
                        } else {
                                move_imm(ctx, t2, off, is32);
                                emit_insn(ctx, stxh, t1, dst, t2);
                        }
                        break;
                case BPF_W:
                        move_imm(ctx, t1, imm, is32);
                        if (is_signed_imm12(off)) {
                                emit_insn(ctx, stw, t1, dst, off);
                        } else if (is_signed_imm14(off)) {
                                emit_insn(ctx, stptrw, t1, dst, off);
                        } else {
                                move_imm(ctx, t2, off, is32);
                                emit_insn(ctx, stxw, t1, dst, t2);
                        }
                        break;
                case BPF_DW:
                        move_imm(ctx, t1, imm, is32);
                        if (is_signed_imm12(off)) {
                                emit_insn(ctx, std, t1, dst, off);
                        } else if (is_signed_imm14(off)) {
                                emit_insn(ctx, stptrd, t1, dst, off);
                        } else {
                                move_imm(ctx, t2, off, is32);
                                emit_insn(ctx, stxd, t1, dst, t2);
                        }
                        break;
                }

                ret = add_exception_handler(insn, ctx, REG_DONT_CLEAR_MARKER);
                if (ret)
                        return ret;
                break;

        /* *(size *)(dst + off) = src */
        case BPF_STX | BPF_MEM | BPF_B:
        case BPF_STX | BPF_MEM | BPF_H:
        case BPF_STX | BPF_MEM | BPF_W:
        case BPF_STX | BPF_MEM | BPF_DW:
        /* STX | PROBE_MEM32: *(size *)(dst + REG_ARENA + off) = src */
        case BPF_STX | BPF_PROBE_MEM32 | BPF_B:
        case BPF_STX | BPF_PROBE_MEM32 | BPF_H:
        case BPF_STX | BPF_PROBE_MEM32 | BPF_W:
        case BPF_STX | BPF_PROBE_MEM32 | BPF_DW:
                if (BPF_MODE(code) == BPF_PROBE_MEM32) {
                        emit_insn(ctx, addd, t2, dst, REG_ARENA);
                        dst = t2;
                }

                switch (BPF_SIZE(code)) {
                case BPF_B:
                        if (is_signed_imm12(off)) {
                                emit_insn(ctx, stb, src, dst, off);
                        } else {
                                move_imm(ctx, t1, off, is32);
                                emit_insn(ctx, stxb, src, dst, t1);
                        }
                        break;
                case BPF_H:
                        if (is_signed_imm12(off)) {
                                emit_insn(ctx, sth, src, dst, off);
                        } else {
                                move_imm(ctx, t1, off, is32);
                                emit_insn(ctx, stxh, src, dst, t1);
                        }
                        break;
                case BPF_W:
                        if (is_signed_imm12(off)) {
                                emit_insn(ctx, stw, src, dst, off);
                        } else if (is_signed_imm14(off)) {
                                emit_insn(ctx, stptrw, src, dst, off);
                        } else {
                                move_imm(ctx, t1, off, is32);
                                emit_insn(ctx, stxw, src, dst, t1);
                        }
                        break;
                case BPF_DW:
                        if (is_signed_imm12(off)) {
                                emit_insn(ctx, std, src, dst, off);
                        } else if (is_signed_imm14(off)) {
                                emit_insn(ctx, stptrd, src, dst, off);
                        } else {
                                move_imm(ctx, t1, off, is32);
                                emit_insn(ctx, stxd, src, dst, t1);
                        }
                        break;
                }

                ret = add_exception_handler(insn, ctx, REG_DONT_CLEAR_MARKER);
                if (ret)
                        return ret;
                break;

        case BPF_STX | BPF_ATOMIC | BPF_W:
        case BPF_STX | BPF_ATOMIC | BPF_DW:
                emit_atomic(insn, ctx);
                break;

        /* Speculation barrier */
        case BPF_ST | BPF_NOSPEC:
                break;

        default:
                pr_err("bpf_jit: unknown opcode %02x\n", code);
                return -EINVAL;
        }

        return 0;

toofar:
        pr_info_once("bpf_jit: opcode %02x, jump too far\n", code);
        return -E2BIG;
}

static int build_body(struct jit_ctx *ctx, bool extra_pass)
{
        int i;
        const struct bpf_prog *prog = ctx->prog;

        for (i = 0; i < prog->len; i++) {
                const struct bpf_insn *insn = &prog->insnsi[i];
                int ret;

                if (ctx->image == NULL)
                        ctx->offset[i] = ctx->idx;

                ret = build_insn(insn, ctx, extra_pass);
                if (ret > 0) {
                        i++;
                        if (ctx->image == NULL)
                                ctx->offset[i] = ctx->idx;
                        continue;
                }
                if (ret)
                        return ret;
        }

        if (ctx->image == NULL)
                ctx->offset[i] = ctx->idx;

        return 0;
}

/* Fill space with break instructions */
static void jit_fill_hole(void *area, unsigned int size)
{
        u32 *ptr;

        /* We are guaranteed to have aligned memory */
        for (ptr = area; size >= sizeof(u32); size -= sizeof(u32))
                *ptr++ = INSN_BREAK;
}

static int validate_code(struct jit_ctx *ctx)
{
        int i;
        union loongarch_instruction insn;

        for (i = 0; i < ctx->idx; i++) {
                insn = ctx->image[i];
                /* Check INSN_BREAK */
                if (insn.word == INSN_BREAK)
                        return -1;
        }

        return 0;
}

static int validate_ctx(struct jit_ctx *ctx)
{
        if (validate_code(ctx))
                return -1;

        if (WARN_ON_ONCE(ctx->num_exentries != ctx->prog->aux->num_exentries))
                return -1;

        return 0;
}

static int emit_jump_and_link(struct jit_ctx *ctx, u8 rd, u64 target)
{
        if (!target) {
                pr_err("bpf_jit: jump target address is error\n");
                return -EFAULT;
        }

        move_imm(ctx, LOONGARCH_GPR_T1, target, false);
        emit_insn(ctx, jirl, rd, LOONGARCH_GPR_T1, 0);

        return 0;
}

static int emit_jump_or_nops(void *target, void *ip, u32 *insns, bool is_call)
{
        int i;
        struct jit_ctx ctx;

        ctx.idx = 0;
        ctx.image = (union loongarch_instruction *)insns;

        if (!target) {
                for (i = 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++)
                        emit_insn((&ctx), nop);
                return 0;
        }

        return emit_jump_and_link(&ctx, is_call ? LOONGARCH_GPR_RA : LOONGARCH_GPR_ZERO, (u64)target);
}

static int emit_call(struct jit_ctx *ctx, u64 addr)
{
        return emit_jump_and_link(ctx, LOONGARCH_GPR_RA, addr);
}

void *bpf_arch_text_copy(void *dst, void *src, size_t len)
{
        int ret;

        cpus_read_lock();
        mutex_lock(&text_mutex);
        ret = larch_insn_text_copy(dst, src, len);
        mutex_unlock(&text_mutex);
        cpus_read_unlock();

        return ret ? ERR_PTR(-EINVAL) : dst;
}

int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
                       enum bpf_text_poke_type new_t, void *old_addr,
                       void *new_addr)
{
        int ret;
        bool is_call;
        unsigned long size = 0;
        unsigned long offset = 0;
        void *image = NULL;
        char namebuf[KSYM_NAME_LEN];
        u32 old_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP};
        u32 new_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP};

        /* Only poking bpf text is supported. Since kernel function entry
         * is set up by ftrace, we rely on ftrace to poke kernel functions.
         */
        if (!bpf_address_lookup((unsigned long)ip, &size, &offset, namebuf))
                return -ENOTSUPP;

        image = ip - offset;

        /* zero offset means we're poking bpf prog entry */
        if (offset == 0) {
                /* skip to the nop instruction in bpf prog entry:
                 * move t0, ra
                 * nop
                 */
                ip = image + LOONGARCH_INSN_SIZE;
        }

        is_call = old_t == BPF_MOD_CALL;
        ret = emit_jump_or_nops(old_addr, ip, old_insns, is_call);
        if (ret)
                return ret;

        if (memcmp(ip, old_insns, LOONGARCH_LONG_JUMP_NBYTES))
                return -EFAULT;

        is_call = new_t == BPF_MOD_CALL;
        ret = emit_jump_or_nops(new_addr, ip, new_insns, is_call);
        if (ret)
                return ret;

        cpus_read_lock();
        mutex_lock(&text_mutex);
        if (memcmp(ip, new_insns, LOONGARCH_LONG_JUMP_NBYTES))
                ret = larch_insn_text_copy(ip, new_insns, LOONGARCH_LONG_JUMP_NBYTES);
        mutex_unlock(&text_mutex);
        cpus_read_unlock();

        return ret;
}

int bpf_arch_text_invalidate(void *dst, size_t len)
{
        int i;
        int ret = 0;
        u32 *inst;

        inst = kvmalloc(len, GFP_KERNEL);
        if (!inst)
                return -ENOMEM;

        for (i = 0; i < (len / sizeof(u32)); i++)
                inst[i] = INSN_BREAK;

        cpus_read_lock();
        mutex_lock(&text_mutex);
        if (larch_insn_text_copy(dst, inst, len))
                ret = -EINVAL;
        mutex_unlock(&text_mutex);
        cpus_read_unlock();

        kvfree(inst);

        return ret;
}

static void store_args(struct jit_ctx *ctx, int nargs, int args_off)
{
        int i;

        for (i = 0; i < nargs; i++) {
                emit_insn(ctx, std, LOONGARCH_GPR_A0 + i, LOONGARCH_GPR_FP, -args_off);
                args_off -= 8;
        }
}

static void restore_args(struct jit_ctx *ctx, int nargs, int args_off)
{
        int i;

        for (i = 0; i < nargs; i++) {
                emit_insn(ctx, ldd, LOONGARCH_GPR_A0 + i, LOONGARCH_GPR_FP, -args_off);
                args_off -= 8;
        }
}

static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_link *l,
                           int args_off, int retval_off, int run_ctx_off, bool save_ret)
{
        int ret;
        u32 *branch;
        struct bpf_prog *p = l->link.prog;
        int cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie);

        if (l->cookie) {
                move_imm(ctx, LOONGARCH_GPR_T1, l->cookie, false);
                emit_insn(ctx, std, LOONGARCH_GPR_T1, LOONGARCH_GPR_FP, -run_ctx_off + cookie_off);
        } else {
                emit_insn(ctx, std, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_FP, -run_ctx_off + cookie_off);
        }

        /* arg1: prog */
        move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p, false);
        /* arg2: &run_ctx */
        emit_insn(ctx, addid, LOONGARCH_GPR_A1, LOONGARCH_GPR_FP, -run_ctx_off);
        ret = emit_call(ctx, (const u64)bpf_trampoline_enter(p));
        if (ret)
                return ret;

        /* store prog start time */
        move_reg(ctx, LOONGARCH_GPR_S1, LOONGARCH_GPR_A0);

        /*
         * if (__bpf_prog_enter(prog) == 0)
         *      goto skip_exec_of_prog;
         */
        branch = (u32 *)ctx->image + ctx->idx;
        /* nop reserved for conditional jump */
        emit_insn(ctx, nop);

        /* arg1: &args_off */
        emit_insn(ctx, addid, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -args_off);
        if (!p->jited)
                move_imm(ctx, LOONGARCH_GPR_A1, (const s64)p->insnsi, false);
        ret = emit_call(ctx, (const u64)p->bpf_func);
        if (ret)
                return ret;

        if (save_ret) {
                emit_insn(ctx, std, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -retval_off);
                emit_insn(ctx, std, regmap[BPF_REG_0], LOONGARCH_GPR_FP, -(retval_off - 8));
        }

        /* update branch with beqz */
        if (ctx->image) {
                int offset = (void *)(&ctx->image[ctx->idx]) - (void *)branch;
                *branch = larch_insn_gen_beq(LOONGARCH_GPR_A0, LOONGARCH_GPR_ZERO, offset);
        }

        /* arg1: prog */
        move_imm(ctx, LOONGARCH_GPR_A0, (const s64)p, false);
        /* arg2: prog start time */
        move_reg(ctx, LOONGARCH_GPR_A1, LOONGARCH_GPR_S1);
        /* arg3: &run_ctx */
        emit_insn(ctx, addid, LOONGARCH_GPR_A2, LOONGARCH_GPR_FP, -run_ctx_off);
        ret = emit_call(ctx, (const u64)bpf_trampoline_exit(p));

        return ret;
}

static void invoke_bpf_mod_ret(struct jit_ctx *ctx, struct bpf_tramp_links *tl,
                               int args_off, int retval_off, int run_ctx_off, u32 **branches)
{
        int i;

        emit_insn(ctx, std, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_FP, -retval_off);
        for (i = 0; i < tl->nr_links; i++) {
                invoke_bpf_prog(ctx, tl->links[i], args_off, retval_off, run_ctx_off, true);
                emit_insn(ctx, ldd, LOONGARCH_GPR_T1, LOONGARCH_GPR_FP, -retval_off);
                branches[i] = (u32 *)ctx->image + ctx->idx;
                emit_insn(ctx, nop);
        }
}

void *arch_alloc_bpf_trampoline(unsigned int size)
{
        return bpf_prog_pack_alloc(size, jit_fill_hole);
}

void arch_free_bpf_trampoline(void *image, unsigned int size)
{
        bpf_prog_pack_free(image, size);
}

int arch_protect_bpf_trampoline(void *image, unsigned int size)
{
        return 0;
}

/*
 * Sign-extend the register if necessary
 */
static void sign_extend(struct jit_ctx *ctx, int rd, int rj, u8 size, bool sign)
{
        /* ABI requires unsigned char/short to be zero-extended */
        if (!sign && (size == 1 || size == 2)) {
                if (rd != rj)
                        move_reg(ctx, rd, rj);
                return;
        }

        switch (size) {
        case 1:
                emit_insn(ctx, extwb, rd, rj);
                break;
        case 2:
                emit_insn(ctx, extwh, rd, rj);
                break;
        case 4:
                emit_insn(ctx, addiw, rd, rj, 0);
                break;
        case 8:
                if (rd != rj)
                        move_reg(ctx, rd, rj);
                break;
        default:
                pr_warn("bpf_jit: invalid size %d for sign_extend\n", size);
        }
}

static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
                                         const struct btf_func_model *m, struct bpf_tramp_links *tlinks,
                                         void *func_addr, u32 flags)
{
        int i, ret, save_ret;
        int stack_size, nargs;
        int retval_off, args_off, nargs_off, ip_off, run_ctx_off, sreg_off, tcc_ptr_off;
        bool is_struct_ops = flags & BPF_TRAMP_F_INDIRECT;
        void *orig_call = func_addr;
        struct bpf_tramp_links *fentry = &tlinks[BPF_TRAMP_FENTRY];
        struct bpf_tramp_links *fexit = &tlinks[BPF_TRAMP_FEXIT];
        struct bpf_tramp_links *fmod_ret = &tlinks[BPF_TRAMP_MODIFY_RETURN];
        u32 **branches = NULL;

        /*
         * FP + 8       [ RA to parent func ] return address to parent
         *                    function
         * FP + 0       [ FP of parent func ] frame pointer of parent
         *                    function
         * FP - 8       [ T0 to traced func ] return address of traced
         *                    function
         * FP - 16      [ FP of traced func ] frame pointer of traced
         *                    function
         *
         * FP - retval_off  [ return value      ] BPF_TRAMP_F_CALL_ORIG or
         *                    BPF_TRAMP_F_RET_FENTRY_RET
         *                  [ argN              ]
         *                  [ ...               ]
         * FP - args_off    [ arg1              ]
         *
         * FP - nargs_off   [ regs count        ]
         *
         * FP - ip_off      [ traced func   ] BPF_TRAMP_F_IP_ARG
         *
         * FP - run_ctx_off [ bpf_tramp_run_ctx ]
         *
         * FP - sreg_off    [ callee saved reg  ]
         *
         * FP - tcc_ptr_off [ tail_call_cnt_ptr ]
         */

        if (m->nr_args > LOONGARCH_MAX_REG_ARGS)
                return -ENOTSUPP;

        /* FIXME: No support of struct argument */
        for (i = 0; i < m->nr_args; i++) {
                if (m->arg_flags[i] & BTF_FMODEL_STRUCT_ARG)
                        return -ENOTSUPP;
        }

        if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY))
                return -ENOTSUPP;

        /* Room of trampoline frame to store return address and frame pointer */
        stack_size = 16;

        save_ret = flags & (BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_RET_FENTRY_RET);
        if (save_ret)
                stack_size += 16; /* Save BPF R0 and A0 */

        retval_off = stack_size;

        /* Room of trampoline frame to store args */
        nargs = m->nr_args;
        stack_size += nargs * 8;
        args_off = stack_size;

        /* Room of trampoline frame to store args number */
        stack_size += 8;
        nargs_off = stack_size;

        /* Room of trampoline frame to store ip address */
        if (flags & BPF_TRAMP_F_IP_ARG) {
                stack_size += 8;
                ip_off = stack_size;
        }

        /* Room of trampoline frame to store struct bpf_tramp_run_ctx */
        stack_size += round_up(sizeof(struct bpf_tramp_run_ctx), 8);
        run_ctx_off = stack_size;

        stack_size += 8;
        sreg_off = stack_size;

        /* Room of trampoline frame to store tail_call_cnt_ptr */
        if (flags & BPF_TRAMP_F_TAIL_CALL_CTX) {
                stack_size += 8;
                tcc_ptr_off = stack_size;
        }

        stack_size = round_up(stack_size, 16);

        if (is_struct_ops) {
                /*
                 * For the trampoline called directly, just handle
                 * the frame of trampoline.
                 */
                emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_size);
                emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, stack_size - 8);
                emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16);
                emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size);
        } else {
                /*
                 * For the trampoline called from function entry,
                 * the frame of traced function and the frame of
                 * trampoline need to be considered.
                 */
                /* RA and FP for parent function */
                emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -16);
                emit_insn(ctx, std, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, 8);
                emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 0);
                emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 16);

                /* RA and FP for traced function */
                emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, -stack_size);
                emit_insn(ctx, std, LOONGARCH_GPR_T0, LOONGARCH_GPR_SP, stack_size - 8);
                emit_insn(ctx, std, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16);
                emit_insn(ctx, addid, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size);
        }

        if (flags & BPF_TRAMP_F_TAIL_CALL_CTX)
                emit_insn(ctx, std, REG_TCC, LOONGARCH_GPR_FP, -tcc_ptr_off);

        /* callee saved register S1 to pass start time */
        emit_insn(ctx, std, LOONGARCH_GPR_S1, LOONGARCH_GPR_FP, -sreg_off);

        /* store ip address of the traced function */
        if (flags & BPF_TRAMP_F_IP_ARG) {
                move_imm(ctx, LOONGARCH_GPR_T1, (const s64)func_addr, false);
                emit_insn(ctx, std, LOONGARCH_GPR_T1, LOONGARCH_GPR_FP, -ip_off);
        }

        /* store nargs number */
        move_imm(ctx, LOONGARCH_GPR_T1, nargs, false);
        emit_insn(ctx, std, LOONGARCH_GPR_T1, LOONGARCH_GPR_FP, -nargs_off);

        store_args(ctx, nargs, args_off);

        /* To traced function */
        /* Ftrace jump skips 2 NOP instructions */
        if (is_kernel_text((unsigned long)orig_call) ||
            is_module_text_address((unsigned long)orig_call))
                orig_call += LOONGARCH_FENTRY_NBYTES;
        /* Direct jump skips 5 NOP instructions */
        else if (is_bpf_text_address((unsigned long)orig_call))
                orig_call += LOONGARCH_BPF_FENTRY_NBYTES;

        if (flags & BPF_TRAMP_F_CALL_ORIG) {
                move_addr(ctx, LOONGARCH_GPR_A0, (const u64)im);
                ret = emit_call(ctx, (const u64)__bpf_tramp_enter);
                if (ret)
                        return ret;
        }

        for (i = 0; i < fentry->nr_links; i++) {
                ret = invoke_bpf_prog(ctx, fentry->links[i], args_off, retval_off,
                                      run_ctx_off, flags & BPF_TRAMP_F_RET_FENTRY_RET);
                if (ret)
                        return ret;
        }
        if (fmod_ret->nr_links) {
                branches  = kcalloc(fmod_ret->nr_links, sizeof(u32 *), GFP_KERNEL);
                if (!branches)
                        return -ENOMEM;

                invoke_bpf_mod_ret(ctx, fmod_ret, args_off, retval_off, run_ctx_off, branches);
        }

        if (flags & BPF_TRAMP_F_CALL_ORIG) {
                restore_args(ctx, m->nr_args, args_off);

                if (flags & BPF_TRAMP_F_TAIL_CALL_CTX)
                        emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_FP, -tcc_ptr_off);

                ret = emit_call(ctx, (const u64)orig_call);
                if (ret)
                        goto out;
                emit_insn(ctx, std, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -retval_off);
                emit_insn(ctx, std, regmap[BPF_REG_0], LOONGARCH_GPR_FP, -(retval_off - 8));
                im->ip_after_call = ctx->ro_image + ctx->idx;
                /* Reserve space for the move_imm + jirl instruction */
                for (i = 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++)
                        emit_insn(ctx, nop);
        }

        for (i = 0; ctx->image && i < fmod_ret->nr_links; i++) {
                int offset = (void *)(&ctx->image[ctx->idx]) - (void *)branches[i];
                *branches[i] = larch_insn_gen_bne(LOONGARCH_GPR_T1, LOONGARCH_GPR_ZERO, offset);
        }

        for (i = 0; i < fexit->nr_links; i++) {
                ret = invoke_bpf_prog(ctx, fexit->links[i], args_off, retval_off, run_ctx_off, false);
                if (ret)
                        goto out;
        }

        if (flags & BPF_TRAMP_F_CALL_ORIG) {
                im->ip_epilogue = ctx->ro_image + ctx->idx;
                move_addr(ctx, LOONGARCH_GPR_A0, (const u64)im);
                ret = emit_call(ctx, (const u64)__bpf_tramp_exit);
                if (ret)
                        goto out;
        }

        if (flags & BPF_TRAMP_F_RESTORE_REGS)
                restore_args(ctx, m->nr_args, args_off);

        if (save_ret) {
                emit_insn(ctx, ldd, regmap[BPF_REG_0], LOONGARCH_GPR_FP, -(retval_off - 8));
                if (is_struct_ops)
                        sign_extend(ctx, LOONGARCH_GPR_A0, regmap[BPF_REG_0],
                                    m->ret_size, m->ret_flags & BTF_FMODEL_SIGNED_ARG);
                else
                        emit_insn(ctx, ldd, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -retval_off);
        }

        emit_insn(ctx, ldd, LOONGARCH_GPR_S1, LOONGARCH_GPR_FP, -sreg_off);

        if (flags & BPF_TRAMP_F_TAIL_CALL_CTX)
                emit_insn(ctx, ldd, REG_TCC, LOONGARCH_GPR_FP, -tcc_ptr_off);

        if (is_struct_ops) {
                /* trampoline called directly */
                emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, stack_size - 8);
                emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16);
                emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_size);

                emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_RA, 0);
        } else {
                /* trampoline called from function entry */
                emit_insn(ctx, ldd, LOONGARCH_GPR_T0, LOONGARCH_GPR_SP, stack_size - 8);
                emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, stack_size - 16);
                emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, stack_size);

                emit_insn(ctx, ldd, LOONGARCH_GPR_RA, LOONGARCH_GPR_SP, 8);
                emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 0);
                emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, 16);

                if (flags & BPF_TRAMP_F_SKIP_FRAME) {
                        /* return to parent function */
                        move_reg(ctx, LOONGARCH_GPR_RA, LOONGARCH_GPR_T0);
                        emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T0, 0);
                } else {
                        /* return to traced function */
                        move_reg(ctx, LOONGARCH_GPR_T1, LOONGARCH_GPR_RA);
                        move_reg(ctx, LOONGARCH_GPR_RA, LOONGARCH_GPR_T0);
                        emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T1, 0);
                }
        }

        ret = ctx->idx;
out:
        kfree(branches);

        return ret;
}

int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *ro_image,
                                void *ro_image_end, const struct btf_func_model *m,
                                u32 flags, struct bpf_tramp_links *tlinks, void *func_addr)
{
        int ret, size;
        void *image, *tmp;
        struct jit_ctx ctx;

        size = ro_image_end - ro_image;
        image = kvmalloc(size, GFP_KERNEL);
        if (!image)
                return -ENOMEM;

        ctx.image = (union loongarch_instruction *)image;
        ctx.ro_image = (union loongarch_instruction *)ro_image;
        ctx.idx = 0;

        jit_fill_hole(image, (unsigned int)(ro_image_end - ro_image));
        ret = __arch_prepare_bpf_trampoline(&ctx, im, m, tlinks, func_addr, flags);
        if (ret < 0)
                goto out;

        if (validate_code(&ctx) < 0) {
                ret = -EINVAL;
                goto out;
        }

        tmp = bpf_arch_text_copy(ro_image, image, size);
        if (IS_ERR(tmp)) {
                ret = PTR_ERR(tmp);
                goto out;
        }

out:
        kvfree(image);
        return ret < 0 ? ret : size;
}

int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
                             struct bpf_tramp_links *tlinks, void *func_addr)
{
        int ret;
        struct jit_ctx ctx;
        struct bpf_tramp_image im;

        ctx.image = NULL;
        ctx.idx = 0;

        ret = __arch_prepare_bpf_trampoline(&ctx, &im, m, tlinks, func_addr, flags);

        return ret < 0 ? ret : ret * LOONGARCH_INSN_SIZE;
}

struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
{
        bool tmp_blinded = false, extra_pass = false;
        u8 *image_ptr, *ro_image_ptr;
        int image_size, prog_size, extable_size;
        struct jit_ctx ctx;
        struct jit_data *jit_data;
        struct bpf_binary_header *header;
        struct bpf_binary_header *ro_header;
        struct bpf_prog *tmp, *orig_prog = prog;

        /*
         * If BPF JIT was not enabled then we must fall back to
         * the interpreter.
         */
        if (!prog->jit_requested)
                return orig_prog;

        tmp = bpf_jit_blind_constants(prog);
        /*
         * If blinding was requested and we failed during blinding,
         * we must fall back to the interpreter. Otherwise, we save
         * the new JITed code.
         */
        if (IS_ERR(tmp))
                return orig_prog;

        if (tmp != prog) {
                tmp_blinded = true;
                prog = tmp;
        }

        jit_data = prog->aux->jit_data;
        if (!jit_data) {
                jit_data = kzalloc_obj(*jit_data);
                if (!jit_data) {
                        prog = orig_prog;
                        goto out;
                }
                prog->aux->jit_data = jit_data;
        }
        if (jit_data->ctx.offset) {
                ctx = jit_data->ctx;
                ro_header = jit_data->ro_header;
                ro_image_ptr = (void *)ctx.ro_image;
                header = jit_data->header;
                image_ptr = (void *)header + ((void *)ro_image_ptr - (void *)ro_header);
                extra_pass = true;
                prog_size = sizeof(u32) * ctx.idx;
                goto skip_init_ctx;
        }

        memset(&ctx, 0, sizeof(ctx));
        ctx.prog = prog;
        ctx.arena_vm_start = bpf_arena_get_kern_vm_start(prog->aux->arena);
        ctx.user_vm_start = bpf_arena_get_user_vm_start(prog->aux->arena);

        ctx.offset = kvcalloc(prog->len + 1, sizeof(u32), GFP_KERNEL);
        if (ctx.offset == NULL) {
                prog = orig_prog;
                goto out_offset;
        }

        /* 1. Initial fake pass to compute ctx->idx and set ctx->flags */
        build_prologue(&ctx);
        if (build_body(&ctx, extra_pass)) {
                prog = orig_prog;
                goto out_offset;
        }
        ctx.epilogue_offset = ctx.idx;
        build_epilogue(&ctx);

        extable_size = prog->aux->num_exentries * sizeof(struct exception_table_entry);

        /* Now we know the actual image size.
         * As each LoongArch instruction is of length 32bit,
         * we are translating number of JITed intructions into
         * the size required to store these JITed code.
         */
        prog_size = sizeof(u32) * ctx.idx;
        image_size = prog_size + extable_size;
        /* Now we know the size of the structure to make */
        ro_header = bpf_jit_binary_pack_alloc(image_size, &ro_image_ptr, sizeof(u32),
                                              &header, &image_ptr, jit_fill_hole);
        if (!ro_header) {
                prog = orig_prog;
                goto out_offset;
        }

        /* 2. Now, the actual pass to generate final JIT code */
        /*
         * Use the image (RW) for writing the JITed instructions. But also save
         * the ro_image (RX) for calculating the offsets in the image. The RW
         * image will be later copied to the RX image from where the program will
         * run. The bpf_jit_binary_pack_finalize() will do this copy in the final
         * step.
         */
        ctx.image = (union loongarch_instruction *)image_ptr;
        ctx.ro_image = (union loongarch_instruction *)ro_image_ptr;
        if (extable_size)
                prog->aux->extable = (void *)ro_image_ptr + prog_size;

skip_init_ctx:
        ctx.idx = 0;
        ctx.num_exentries = 0;

        build_prologue(&ctx);
        if (build_body(&ctx, extra_pass)) {
                prog = orig_prog;
                goto out_free;
        }
        build_epilogue(&ctx);

        /* 3. Extra pass to validate JITed code */
        if (validate_ctx(&ctx)) {
                prog = orig_prog;
                goto out_free;
        }

        /* And we're done */
        if (bpf_jit_enable > 1)
                bpf_jit_dump(prog->len, prog_size, 2, ctx.image);

        if (!prog->is_func || extra_pass) {
                if (extra_pass && ctx.idx != jit_data->ctx.idx) {
                        pr_err_once("multi-func JIT bug %d != %d\n",
                                    ctx.idx, jit_data->ctx.idx);
                        goto out_free;
                }
                if (WARN_ON(bpf_jit_binary_pack_finalize(ro_header, header))) {
                        /* ro_header has been freed */
                        ro_header = NULL;
                        prog = orig_prog;
                        goto out_free;
                }
                /*
                 * The instructions have now been copied to the ROX region from
                 * where they will execute. Now the data cache has to be cleaned
                 * to the PoU and the I-cache has to be invalidated for the VAs.
                 */
                bpf_flush_icache(ro_header, ctx.ro_image + ctx.idx);
        } else {
                jit_data->ctx = ctx;
                jit_data->header = header;
                jit_data->ro_header = ro_header;
        }
        prog->jited = 1;
        prog->jited_len = prog_size;
        prog->bpf_func = (void *)ctx.ro_image;

        if (!prog->is_func || extra_pass) {
                int i;

                /* offset[prog->len] is the size of program */
                for (i = 0; i <= prog->len; i++)
                        ctx.offset[i] *= LOONGARCH_INSN_SIZE;
                bpf_prog_fill_jited_linfo(prog, ctx.offset + 1);

out_offset:
                kvfree(ctx.offset);
                kfree(jit_data);
                prog->aux->jit_data = NULL;
        }

out:
        if (tmp_blinded)
                bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog);

        return prog;

out_free:
        if (header) {
                bpf_arch_text_copy(&ro_header->size, &header->size, sizeof(header->size));
                bpf_jit_binary_pack_free(ro_header, header);
        }
        goto out_offset;
}

void bpf_jit_free(struct bpf_prog *prog)
{
        if (prog->jited) {
                struct jit_data *jit_data = prog->aux->jit_data;
                struct bpf_binary_header *hdr;

                /*
                 * If we fail the final pass of JIT (from jit_subprogs), the
                 * program may not be finalized yet. Call finalize here before
                 * freeing it.
                 */
                if (jit_data) {
                        bpf_jit_binary_pack_finalize(jit_data->ro_header, jit_data->header);
                        kfree(jit_data);
                }
                hdr = bpf_jit_binary_pack_hdr(prog);
                bpf_jit_binary_pack_free(hdr, NULL);
                WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(prog));
        }

        bpf_prog_unlock_free(prog);
}

bool bpf_jit_bypass_spec_v1(void)
{
        return true;
}

bool bpf_jit_bypass_spec_v4(void)
{
        return true;
}

bool bpf_jit_supports_arena(void)
{
        return true;
}

/* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */
bool bpf_jit_supports_subprog_tailcalls(void)
{
        return true;
}