GNU Linux-libre 4.9-gnu1

[releases.git] / drivers / net / ethernet / netronome / nfp / nfp_bpf_jit.c

/*
 * Copyright (C) 2016 Netronome Systems, Inc.
 *
 * This software is dual licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#define pr_fmt(fmt)     "NFP net bpf: " fmt

#include <linux/kernel.h>
#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/pkt_cls.h>
#include <linux/unistd.h>

#include "nfp_asm.h"
#include "nfp_bpf.h"

/* --- NFP prog --- */
/* Foreach "multiple" entries macros provide pos and next<n> pointers.
 * It's safe to modify the next pointers (but not pos).
 */
#define nfp_for_each_insn_walk2(nfp_prog, pos, next)                    \
        for (pos = list_first_entry(&(nfp_prog)->insns, typeof(*pos), l), \
             next = list_next_entry(pos, l);                    \
             &(nfp_prog)->insns != &pos->l &&                   \
             &(nfp_prog)->insns != &next->l;                    \
             pos = nfp_meta_next(pos),                          \
             next = nfp_meta_next(pos))

#define nfp_for_each_insn_walk3(nfp_prog, pos, next, next2)             \
        for (pos = list_first_entry(&(nfp_prog)->insns, typeof(*pos), l), \
             next = list_next_entry(pos, l),                    \
             next2 = list_next_entry(next, l);                  \
             &(nfp_prog)->insns != &pos->l &&                   \
             &(nfp_prog)->insns != &next->l &&                  \
             &(nfp_prog)->insns != &next2->l;                   \
             pos = nfp_meta_next(pos),                          \
             next = nfp_meta_next(pos),                         \
             next2 = nfp_meta_next(next))

static bool
nfp_meta_has_next(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return meta->l.next != &nfp_prog->insns;
}

static bool
nfp_meta_has_prev(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return meta->l.prev != &nfp_prog->insns;
}

static void nfp_prog_free(struct nfp_prog *nfp_prog)
{
        struct nfp_insn_meta *meta, *tmp;

        list_for_each_entry_safe(meta, tmp, &nfp_prog->insns, l) {
                list_del(&meta->l);
                kfree(meta);
        }
        kfree(nfp_prog);
}

static void nfp_prog_push(struct nfp_prog *nfp_prog, u64 insn)
{
        if (nfp_prog->__prog_alloc_len == nfp_prog->prog_len) {
                nfp_prog->error = -ENOSPC;
                return;
        }

        nfp_prog->prog[nfp_prog->prog_len] = insn;
        nfp_prog->prog_len++;
}

static unsigned int nfp_prog_current_offset(struct nfp_prog *nfp_prog)
{
        return nfp_prog->start_off + nfp_prog->prog_len;
}

static unsigned int
nfp_prog_offset_to_index(struct nfp_prog *nfp_prog, unsigned int offset)
{
        return offset - nfp_prog->start_off;
}

/* --- SW reg --- */
struct nfp_insn_ur_regs {
        enum alu_dst_ab dst_ab;
        u16 dst;
        u16 areg, breg;
        bool swap;
        bool wr_both;
};

struct nfp_insn_re_regs {
        enum alu_dst_ab dst_ab;
        u8 dst;
        u8 areg, breg;
        bool swap;
        bool wr_both;
        bool i8;
};

static u16 nfp_swreg_to_unreg(u32 swreg, bool is_dst)
{
        u16 val = FIELD_GET(NN_REG_VAL, swreg);

        switch (FIELD_GET(NN_REG_TYPE, swreg)) {
        case NN_REG_GPR_A:
        case NN_REG_GPR_B:
        case NN_REG_GPR_BOTH:
                return val;
        case NN_REG_NNR:
                return UR_REG_NN | val;
        case NN_REG_XFER:
                return UR_REG_XFR | val;
        case NN_REG_IMM:
                if (val & ~0xff) {
                        pr_err("immediate too large\n");
                        return 0;
                }
                return UR_REG_IMM_encode(val);
        case NN_REG_NONE:
                return is_dst ? UR_REG_NO_DST : REG_NONE;
        default:
                pr_err("unrecognized reg encoding %08x\n", swreg);
                return 0;
        }
}

static int
swreg_to_unrestricted(u32 dst, u32 lreg, u32 rreg, struct nfp_insn_ur_regs *reg)
{
        memset(reg, 0, sizeof(*reg));

        /* Decode destination */
        if (FIELD_GET(NN_REG_TYPE, dst) == NN_REG_IMM)
                return -EFAULT;

        if (FIELD_GET(NN_REG_TYPE, dst) == NN_REG_GPR_B)
                reg->dst_ab = ALU_DST_B;
        if (FIELD_GET(NN_REG_TYPE, dst) == NN_REG_GPR_BOTH)
                reg->wr_both = true;
        reg->dst = nfp_swreg_to_unreg(dst, true);

        /* Decode source operands */
        if (FIELD_GET(NN_REG_TYPE, lreg) == FIELD_GET(NN_REG_TYPE, rreg))
                return -EFAULT;

        if (FIELD_GET(NN_REG_TYPE, lreg) == NN_REG_GPR_B ||
            FIELD_GET(NN_REG_TYPE, rreg) == NN_REG_GPR_A) {
                reg->areg = nfp_swreg_to_unreg(rreg, false);
                reg->breg = nfp_swreg_to_unreg(lreg, false);
                reg->swap = true;
        } else {
                reg->areg = nfp_swreg_to_unreg(lreg, false);
                reg->breg = nfp_swreg_to_unreg(rreg, false);
        }

        return 0;
}

static u16 nfp_swreg_to_rereg(u32 swreg, bool is_dst, bool has_imm8, bool *i8)
{
        u16 val = FIELD_GET(NN_REG_VAL, swreg);

        switch (FIELD_GET(NN_REG_TYPE, swreg)) {
        case NN_REG_GPR_A:
        case NN_REG_GPR_B:
        case NN_REG_GPR_BOTH:
                return val;
        case NN_REG_XFER:
                return RE_REG_XFR | val;
        case NN_REG_IMM:
                if (val & ~(0x7f | has_imm8 << 7)) {
                        pr_err("immediate too large\n");
                        return 0;
                }
                *i8 = val & 0x80;
                return RE_REG_IMM_encode(val & 0x7f);
        case NN_REG_NONE:
                return is_dst ? RE_REG_NO_DST : REG_NONE;
        default:
                pr_err("unrecognized reg encoding\n");
                return 0;
        }
}

static int
swreg_to_restricted(u32 dst, u32 lreg, u32 rreg, struct nfp_insn_re_regs *reg,
                    bool has_imm8)
{
        memset(reg, 0, sizeof(*reg));

        /* Decode destination */
        if (FIELD_GET(NN_REG_TYPE, dst) == NN_REG_IMM)
                return -EFAULT;

        if (FIELD_GET(NN_REG_TYPE, dst) == NN_REG_GPR_B)
                reg->dst_ab = ALU_DST_B;
        if (FIELD_GET(NN_REG_TYPE, dst) == NN_REG_GPR_BOTH)
                reg->wr_both = true;
        reg->dst = nfp_swreg_to_rereg(dst, true, false, NULL);

        /* Decode source operands */
        if (FIELD_GET(NN_REG_TYPE, lreg) == FIELD_GET(NN_REG_TYPE, rreg))
                return -EFAULT;

        if (FIELD_GET(NN_REG_TYPE, lreg) == NN_REG_GPR_B ||
            FIELD_GET(NN_REG_TYPE, rreg) == NN_REG_GPR_A) {
                reg->areg = nfp_swreg_to_rereg(rreg, false, has_imm8, &reg->i8);
                reg->breg = nfp_swreg_to_rereg(lreg, false, has_imm8, &reg->i8);
                reg->swap = true;
        } else {
                reg->areg = nfp_swreg_to_rereg(lreg, false, has_imm8, &reg->i8);
                reg->breg = nfp_swreg_to_rereg(rreg, false, has_imm8, &reg->i8);
        }

        return 0;
}

/* --- Emitters --- */
static const struct cmd_tgt_act cmd_tgt_act[__CMD_TGT_MAP_SIZE] = {
        [CMD_TGT_WRITE8] =              { 0x00, 0x42 },
        [CMD_TGT_READ8] =               { 0x01, 0x43 },
        [CMD_TGT_READ_LE] =             { 0x01, 0x40 },
        [CMD_TGT_READ_SWAP_LE] =        { 0x03, 0x40 },
};

static void
__emit_cmd(struct nfp_prog *nfp_prog, enum cmd_tgt_map op,
           u8 mode, u8 xfer, u8 areg, u8 breg, u8 size, bool sync)
{
        enum cmd_ctx_swap ctx;
        u64 insn;

        if (sync)
                ctx = CMD_CTX_SWAP;
        else
                ctx = CMD_CTX_NO_SWAP;

        insn =  FIELD_PREP(OP_CMD_A_SRC, areg) |
                FIELD_PREP(OP_CMD_CTX, ctx) |
                FIELD_PREP(OP_CMD_B_SRC, breg) |
                FIELD_PREP(OP_CMD_TOKEN, cmd_tgt_act[op].token) |
                FIELD_PREP(OP_CMD_XFER, xfer) |
                FIELD_PREP(OP_CMD_CNT, size) |
                FIELD_PREP(OP_CMD_SIG, sync) |
                FIELD_PREP(OP_CMD_TGT_CMD, cmd_tgt_act[op].tgt_cmd) |
                FIELD_PREP(OP_CMD_MODE, mode);

        nfp_prog_push(nfp_prog, insn);
}

static void
emit_cmd(struct nfp_prog *nfp_prog, enum cmd_tgt_map op,
         u8 mode, u8 xfer, u32 lreg, u32 rreg, u8 size, bool sync)
{
        struct nfp_insn_re_regs reg;
        int err;

        err = swreg_to_restricted(reg_none(), lreg, rreg, &reg, false);
        if (err) {
                nfp_prog->error = err;
                return;
        }
        if (reg.swap) {
                pr_err("cmd can't swap arguments\n");
                nfp_prog->error = -EFAULT;
                return;
        }

        __emit_cmd(nfp_prog, op, mode, xfer, reg.areg, reg.breg, size, sync);
}

static void
__emit_br(struct nfp_prog *nfp_prog, enum br_mask mask, enum br_ev_pip ev_pip,
          enum br_ctx_signal_state css, u16 addr, u8 defer)
{
        u16 addr_lo, addr_hi;
        u64 insn;

        addr_lo = addr & (OP_BR_ADDR_LO >> __bf_shf(OP_BR_ADDR_LO));
        addr_hi = addr != addr_lo;

        insn = OP_BR_BASE |
                FIELD_PREP(OP_BR_MASK, mask) |
                FIELD_PREP(OP_BR_EV_PIP, ev_pip) |
                FIELD_PREP(OP_BR_CSS, css) |
                FIELD_PREP(OP_BR_DEFBR, defer) |
                FIELD_PREP(OP_BR_ADDR_LO, addr_lo) |
                FIELD_PREP(OP_BR_ADDR_HI, addr_hi);

        nfp_prog_push(nfp_prog, insn);
}

static void emit_br_def(struct nfp_prog *nfp_prog, u16 addr, u8 defer)
{
        if (defer > 2) {
                pr_err("BUG: branch defer out of bounds %d\n", defer);
                nfp_prog->error = -EFAULT;
                return;
        }
        __emit_br(nfp_prog, BR_UNC, BR_EV_PIP_UNCOND, BR_CSS_NONE, addr, defer);
}

static void
emit_br(struct nfp_prog *nfp_prog, enum br_mask mask, u16 addr, u8 defer)
{
        __emit_br(nfp_prog, mask,
                  mask != BR_UNC ? BR_EV_PIP_COND : BR_EV_PIP_UNCOND,
                  BR_CSS_NONE, addr, defer);
}

static void
__emit_br_byte(struct nfp_prog *nfp_prog, u8 areg, u8 breg, bool imm8,
               u8 byte, bool equal, u16 addr, u8 defer)
{
        u16 addr_lo, addr_hi;
        u64 insn;

        addr_lo = addr & (OP_BB_ADDR_LO >> __bf_shf(OP_BB_ADDR_LO));
        addr_hi = addr != addr_lo;

        insn = OP_BBYTE_BASE |
                FIELD_PREP(OP_BB_A_SRC, areg) |
                FIELD_PREP(OP_BB_BYTE, byte) |
                FIELD_PREP(OP_BB_B_SRC, breg) |
                FIELD_PREP(OP_BB_I8, imm8) |
                FIELD_PREP(OP_BB_EQ, equal) |
                FIELD_PREP(OP_BB_DEFBR, defer) |
                FIELD_PREP(OP_BB_ADDR_LO, addr_lo) |
                FIELD_PREP(OP_BB_ADDR_HI, addr_hi);

        nfp_prog_push(nfp_prog, insn);
}

static void
emit_br_byte_neq(struct nfp_prog *nfp_prog,
                 u32 dst, u8 imm, u8 byte, u16 addr, u8 defer)
{
        struct nfp_insn_re_regs reg;
        int err;

        err = swreg_to_restricted(reg_none(), dst, reg_imm(imm), &reg, true);
        if (err) {
                nfp_prog->error = err;
                return;
        }

        __emit_br_byte(nfp_prog, reg.areg, reg.breg, reg.i8, byte, false, addr,
                       defer);
}

static void
__emit_immed(struct nfp_prog *nfp_prog, u16 areg, u16 breg, u16 imm_hi,
             enum immed_width width, bool invert,
             enum immed_shift shift, bool wr_both)
{
        u64 insn;

        insn = OP_IMMED_BASE |
                FIELD_PREP(OP_IMMED_A_SRC, areg) |
                FIELD_PREP(OP_IMMED_B_SRC, breg) |
                FIELD_PREP(OP_IMMED_IMM, imm_hi) |
                FIELD_PREP(OP_IMMED_WIDTH, width) |
                FIELD_PREP(OP_IMMED_INV, invert) |
                FIELD_PREP(OP_IMMED_SHIFT, shift) |
                FIELD_PREP(OP_IMMED_WR_AB, wr_both);

        nfp_prog_push(nfp_prog, insn);
}

static void
emit_immed(struct nfp_prog *nfp_prog, u32 dst, u16 imm,
           enum immed_width width, bool invert, enum immed_shift shift)
{
        struct nfp_insn_ur_regs reg;
        int err;

        if (FIELD_GET(NN_REG_TYPE, dst) == NN_REG_IMM) {
                nfp_prog->error = -EFAULT;
                return;
        }

        err = swreg_to_unrestricted(dst, dst, reg_imm(imm & 0xff), &reg);
        if (err) {
                nfp_prog->error = err;
                return;
        }

        __emit_immed(nfp_prog, reg.areg, reg.breg, imm >> 8, width,
                     invert, shift, reg.wr_both);
}

static void
__emit_shf(struct nfp_prog *nfp_prog, u16 dst, enum alu_dst_ab dst_ab,
           enum shf_sc sc, u8 shift,
           u16 areg, enum shf_op op, u16 breg, bool i8, bool sw, bool wr_both)
{
        u64 insn;

        if (!FIELD_FIT(OP_SHF_SHIFT, shift)) {
                nfp_prog->error = -EFAULT;
                return;
        }

        if (sc == SHF_SC_L_SHF)
                shift = 32 - shift;

        insn = OP_SHF_BASE |
                FIELD_PREP(OP_SHF_A_SRC, areg) |
                FIELD_PREP(OP_SHF_SC, sc) |
                FIELD_PREP(OP_SHF_B_SRC, breg) |
                FIELD_PREP(OP_SHF_I8, i8) |
                FIELD_PREP(OP_SHF_SW, sw) |
                FIELD_PREP(OP_SHF_DST, dst) |
                FIELD_PREP(OP_SHF_SHIFT, shift) |
                FIELD_PREP(OP_SHF_OP, op) |
                FIELD_PREP(OP_SHF_DST_AB, dst_ab) |
                FIELD_PREP(OP_SHF_WR_AB, wr_both);

        nfp_prog_push(nfp_prog, insn);
}

static void
emit_shf(struct nfp_prog *nfp_prog, u32 dst, u32 lreg, enum shf_op op, u32 rreg,
         enum shf_sc sc, u8 shift)
{
        struct nfp_insn_re_regs reg;
        int err;

        err = swreg_to_restricted(dst, lreg, rreg, &reg, true);
        if (err) {
                nfp_prog->error = err;
                return;
        }

        __emit_shf(nfp_prog, reg.dst, reg.dst_ab, sc, shift,
                   reg.areg, op, reg.breg, reg.i8, reg.swap, reg.wr_both);
}

static void
__emit_alu(struct nfp_prog *nfp_prog, u16 dst, enum alu_dst_ab dst_ab,
           u16 areg, enum alu_op op, u16 breg, bool swap, bool wr_both)
{
        u64 insn;

        insn = OP_ALU_BASE |
                FIELD_PREP(OP_ALU_A_SRC, areg) |
                FIELD_PREP(OP_ALU_B_SRC, breg) |
                FIELD_PREP(OP_ALU_DST, dst) |
                FIELD_PREP(OP_ALU_SW, swap) |
                FIELD_PREP(OP_ALU_OP, op) |
                FIELD_PREP(OP_ALU_DST_AB, dst_ab) |
                FIELD_PREP(OP_ALU_WR_AB, wr_both);

        nfp_prog_push(nfp_prog, insn);
}

static void
emit_alu(struct nfp_prog *nfp_prog, u32 dst, u32 lreg, enum alu_op op, u32 rreg)
{
        struct nfp_insn_ur_regs reg;
        int err;

        err = swreg_to_unrestricted(dst, lreg, rreg, &reg);
        if (err) {
                nfp_prog->error = err;
                return;
        }

        __emit_alu(nfp_prog, reg.dst, reg.dst_ab,
                   reg.areg, op, reg.breg, reg.swap, reg.wr_both);
}

static void
__emit_ld_field(struct nfp_prog *nfp_prog, enum shf_sc sc,
                u8 areg, u8 bmask, u8 breg, u8 shift, bool imm8,
                bool zero, bool swap, bool wr_both)
{
        u64 insn;

        insn = OP_LDF_BASE |
                FIELD_PREP(OP_LDF_A_SRC, areg) |
                FIELD_PREP(OP_LDF_SC, sc) |
                FIELD_PREP(OP_LDF_B_SRC, breg) |
                FIELD_PREP(OP_LDF_I8, imm8) |
                FIELD_PREP(OP_LDF_SW, swap) |
                FIELD_PREP(OP_LDF_ZF, zero) |
                FIELD_PREP(OP_LDF_BMASK, bmask) |
                FIELD_PREP(OP_LDF_SHF, shift) |
                FIELD_PREP(OP_LDF_WR_AB, wr_both);

        nfp_prog_push(nfp_prog, insn);
}

static void
emit_ld_field_any(struct nfp_prog *nfp_prog, enum shf_sc sc, u8 shift,
                  u32 dst, u8 bmask, u32 src, bool zero)
{
        struct nfp_insn_re_regs reg;
        int err;

        err = swreg_to_restricted(reg_none(), dst, src, &reg, true);
        if (err) {
                nfp_prog->error = err;
                return;
        }

        __emit_ld_field(nfp_prog, sc, reg.areg, bmask, reg.breg, shift,
                        reg.i8, zero, reg.swap, reg.wr_both);
}

static void
emit_ld_field(struct nfp_prog *nfp_prog, u32 dst, u8 bmask, u32 src,
              enum shf_sc sc, u8 shift)
{
        emit_ld_field_any(nfp_prog, sc, shift, dst, bmask, src, false);
}

/* --- Wrappers --- */
static bool pack_immed(u32 imm, u16 *val, enum immed_shift *shift)
{
        if (!(imm & 0xffff0000)) {
                *val = imm;
                *shift = IMMED_SHIFT_0B;
        } else if (!(imm & 0xff0000ff)) {
                *val = imm >> 8;
                *shift = IMMED_SHIFT_1B;
        } else if (!(imm & 0x0000ffff)) {
                *val = imm >> 16;
                *shift = IMMED_SHIFT_2B;
        } else {
                return false;
        }

        return true;
}

static void wrp_immed(struct nfp_prog *nfp_prog, u32 dst, u32 imm)
{
        enum immed_shift shift;
        u16 val;

        if (pack_immed(imm, &val, &shift)) {
                emit_immed(nfp_prog, dst, val, IMMED_WIDTH_ALL, false, shift);
        } else if (pack_immed(~imm, &val, &shift)) {
                emit_immed(nfp_prog, dst, val, IMMED_WIDTH_ALL, true, shift);
        } else {
                emit_immed(nfp_prog, dst, imm & 0xffff, IMMED_WIDTH_ALL,
                           false, IMMED_SHIFT_0B);
                emit_immed(nfp_prog, dst, imm >> 16, IMMED_WIDTH_WORD,
                           false, IMMED_SHIFT_2B);
        }
}

/* ur_load_imm_any() - encode immediate or use tmp register (unrestricted)
 * If the @imm is small enough encode it directly in operand and return
 * otherwise load @imm to a spare register and return its encoding.
 */
static u32 ur_load_imm_any(struct nfp_prog *nfp_prog, u32 imm, u32 tmp_reg)
{
        if (FIELD_FIT(UR_REG_IMM_MAX, imm))
                return reg_imm(imm);

        wrp_immed(nfp_prog, tmp_reg, imm);
        return tmp_reg;
}

/* re_load_imm_any() - encode immediate or use tmp register (restricted)
 * If the @imm is small enough encode it directly in operand and return
 * otherwise load @imm to a spare register and return its encoding.
 */
static u32 re_load_imm_any(struct nfp_prog *nfp_prog, u32 imm, u32 tmp_reg)
{
        if (FIELD_FIT(RE_REG_IMM_MAX, imm))
                return reg_imm(imm);

        wrp_immed(nfp_prog, tmp_reg, imm);
        return tmp_reg;
}

static void
wrp_br_special(struct nfp_prog *nfp_prog, enum br_mask mask,
               enum br_special special)
{
        emit_br(nfp_prog, mask, 0, 0);

        nfp_prog->prog[nfp_prog->prog_len - 1] |=
                FIELD_PREP(OP_BR_SPECIAL, special);
}

static void wrp_reg_mov(struct nfp_prog *nfp_prog, u16 dst, u16 src)
{
        emit_alu(nfp_prog, reg_both(dst), reg_none(), ALU_OP_NONE, reg_b(src));
}

static int
construct_data_ind_ld(struct nfp_prog *nfp_prog, u16 offset,
                      u16 src, bool src_valid, u8 size)
{
        unsigned int i;
        u16 shift, sz;
        u32 tmp_reg;

        /* We load the value from the address indicated in @offset and then
         * shift out the data we don't need.  Note: this is big endian!
         */
        sz = size < 4 ? 4 : size;
        shift = size < 4 ? 4 - size : 0;

        if (src_valid) {
                /* Calculate the true offset (src_reg + imm) */
                tmp_reg = ur_load_imm_any(nfp_prog, offset, imm_b(nfp_prog));
                emit_alu(nfp_prog, imm_both(nfp_prog),
                         reg_a(src), ALU_OP_ADD, tmp_reg);
                /* Check packet length (size guaranteed to fit b/c it's u8) */
                emit_alu(nfp_prog, imm_a(nfp_prog),
                         imm_a(nfp_prog), ALU_OP_ADD, reg_imm(size));
                emit_alu(nfp_prog, reg_none(),
                         NFP_BPF_ABI_LEN, ALU_OP_SUB, imm_a(nfp_prog));
                wrp_br_special(nfp_prog, BR_BLO, OP_BR_GO_ABORT);
                /* Load data */
                emit_cmd(nfp_prog, CMD_TGT_READ8, CMD_MODE_32b, 0,
                         pkt_reg(nfp_prog), imm_b(nfp_prog), sz - 1, true);
        } else {
                /* Check packet length */
                tmp_reg = ur_load_imm_any(nfp_prog, offset + size,
                                          imm_a(nfp_prog));
                emit_alu(nfp_prog, reg_none(),
                         NFP_BPF_ABI_LEN, ALU_OP_SUB, tmp_reg);
                wrp_br_special(nfp_prog, BR_BLO, OP_BR_GO_ABORT);
                /* Load data */
                tmp_reg = re_load_imm_any(nfp_prog, offset, imm_b(nfp_prog));
                emit_cmd(nfp_prog, CMD_TGT_READ8, CMD_MODE_32b, 0,
                         pkt_reg(nfp_prog), tmp_reg, sz - 1, true);
        }

        i = 0;
        if (shift)
                emit_shf(nfp_prog, reg_both(0), reg_none(), SHF_OP_NONE,
                         reg_xfer(0), SHF_SC_R_SHF, shift * 8);
        else
                for (; i * 4 < size; i++)
                        emit_alu(nfp_prog, reg_both(i),
                                 reg_none(), ALU_OP_NONE, reg_xfer(i));

        if (i < 2)
                wrp_immed(nfp_prog, reg_both(1), 0);

        return 0;
}

static int construct_data_ld(struct nfp_prog *nfp_prog, u16 offset, u8 size)
{
        return construct_data_ind_ld(nfp_prog, offset, 0, false, size);
}

static int wrp_set_mark(struct nfp_prog *nfp_prog, u8 src)
{
        emit_alu(nfp_prog, NFP_BPF_ABI_MARK,
                 reg_none(), ALU_OP_NONE, reg_b(src));
        emit_alu(nfp_prog, NFP_BPF_ABI_FLAGS,
                 NFP_BPF_ABI_FLAGS, ALU_OP_OR, reg_imm(NFP_BPF_ABI_FLAG_MARK));

        return 0;
}

static void
wrp_alu_imm(struct nfp_prog *nfp_prog, u8 dst, enum alu_op alu_op, u32 imm)
{
        u32 tmp_reg;

        if (alu_op == ALU_OP_AND) {
                if (!imm)
                        wrp_immed(nfp_prog, reg_both(dst), 0);
                if (!imm || !~imm)
                        return;
        }
        if (alu_op == ALU_OP_OR) {
                if (!~imm)
                        wrp_immed(nfp_prog, reg_both(dst), ~0U);
                if (!imm || !~imm)
                        return;
        }
        if (alu_op == ALU_OP_XOR) {
                if (!~imm)
                        emit_alu(nfp_prog, reg_both(dst), reg_none(),
                                 ALU_OP_NEG, reg_b(dst));
                if (!imm || !~imm)
                        return;
        }

        tmp_reg = ur_load_imm_any(nfp_prog, imm, imm_b(nfp_prog));
        emit_alu(nfp_prog, reg_both(dst), reg_a(dst), alu_op, tmp_reg);
}

static int
wrp_alu64_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
              enum alu_op alu_op, bool skip)
{
        const struct bpf_insn *insn = &meta->insn;
        u64 imm = insn->imm; /* sign extend */

        if (skip) {
                meta->skip = true;
                return 0;
        }

        wrp_alu_imm(nfp_prog, insn->dst_reg * 2, alu_op, imm & ~0U);
        wrp_alu_imm(nfp_prog, insn->dst_reg * 2 + 1, alu_op, imm >> 32);

        return 0;
}

static int
wrp_alu64_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
              enum alu_op alu_op)
{
        u8 dst = meta->insn.dst_reg * 2, src = meta->insn.src_reg * 2;

        emit_alu(nfp_prog, reg_both(dst), reg_a(dst), alu_op, reg_b(src));
        emit_alu(nfp_prog, reg_both(dst + 1),
                 reg_a(dst + 1), alu_op, reg_b(src + 1));

        return 0;
}

static int
wrp_alu32_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
              enum alu_op alu_op, bool skip)
{
        const struct bpf_insn *insn = &meta->insn;

        if (skip) {
                meta->skip = true;
                return 0;
        }

        wrp_alu_imm(nfp_prog, insn->dst_reg * 2, alu_op, insn->imm);
        wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2 + 1), 0);

        return 0;
}

static int
wrp_alu32_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
              enum alu_op alu_op)
{
        u8 dst = meta->insn.dst_reg * 2, src = meta->insn.src_reg * 2;

        emit_alu(nfp_prog, reg_both(dst), reg_a(dst), alu_op, reg_b(src));
        wrp_immed(nfp_prog, reg_both(meta->insn.dst_reg * 2 + 1), 0);

        return 0;
}

static void
wrp_test_reg_one(struct nfp_prog *nfp_prog, u8 dst, enum alu_op alu_op, u8 src,
                 enum br_mask br_mask, u16 off)
{
        emit_alu(nfp_prog, reg_none(), reg_a(dst), alu_op, reg_b(src));
        emit_br(nfp_prog, br_mask, off, 0);
}

static int
wrp_test_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
             enum alu_op alu_op, enum br_mask br_mask)
{
        const struct bpf_insn *insn = &meta->insn;

        if (insn->off < 0) /* TODO */
                return -ENOTSUPP;

        wrp_test_reg_one(nfp_prog, insn->dst_reg * 2, alu_op,
                         insn->src_reg * 2, br_mask, insn->off);
        wrp_test_reg_one(nfp_prog, insn->dst_reg * 2 + 1, alu_op,
                         insn->src_reg * 2 + 1, br_mask, insn->off);

        return 0;
}

static int
wrp_cmp_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
            enum br_mask br_mask, bool swap)
{
        const struct bpf_insn *insn = &meta->insn;
        u64 imm = insn->imm; /* sign extend */
        u8 reg = insn->dst_reg * 2;
        u32 tmp_reg;

        if (insn->off < 0) /* TODO */
                return -ENOTSUPP;

        tmp_reg = ur_load_imm_any(nfp_prog, imm & ~0U, imm_b(nfp_prog));
        if (!swap)
                emit_alu(nfp_prog, reg_none(), reg_a(reg), ALU_OP_SUB, tmp_reg);
        else
                emit_alu(nfp_prog, reg_none(), tmp_reg, ALU_OP_SUB, reg_a(reg));

        tmp_reg = ur_load_imm_any(nfp_prog, imm >> 32, imm_b(nfp_prog));
        if (!swap)
                emit_alu(nfp_prog, reg_none(),
                         reg_a(reg + 1), ALU_OP_SUB_C, tmp_reg);
        else
                emit_alu(nfp_prog, reg_none(),
                         tmp_reg, ALU_OP_SUB_C, reg_a(reg + 1));

        emit_br(nfp_prog, br_mask, insn->off, 0);

        return 0;
}

static int
wrp_cmp_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
            enum br_mask br_mask, bool swap)
{
        const struct bpf_insn *insn = &meta->insn;
        u8 areg = insn->src_reg * 2, breg = insn->dst_reg * 2;

        if (insn->off < 0) /* TODO */
                return -ENOTSUPP;

        if (swap) {
                areg ^= breg;
                breg ^= areg;
                areg ^= breg;
        }

        emit_alu(nfp_prog, reg_none(), reg_a(areg), ALU_OP_SUB, reg_b(breg));
        emit_alu(nfp_prog, reg_none(),
                 reg_a(areg + 1), ALU_OP_SUB_C, reg_b(breg + 1));
        emit_br(nfp_prog, br_mask, insn->off, 0);

        return 0;
}

/* --- Callbacks --- */
static int mov_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        wrp_reg_mov(nfp_prog, insn->dst_reg * 2, insn->src_reg * 2);
        wrp_reg_mov(nfp_prog, insn->dst_reg * 2 + 1, insn->src_reg * 2 + 1);

        return 0;
}

static int mov_imm64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        u64 imm = meta->insn.imm; /* sign extend */

        wrp_immed(nfp_prog, reg_both(meta->insn.dst_reg * 2), imm & ~0U);
        wrp_immed(nfp_prog, reg_both(meta->insn.dst_reg * 2 + 1), imm >> 32);

        return 0;
}

static int xor_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu64_reg(nfp_prog, meta, ALU_OP_XOR);
}

static int xor_imm64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu64_imm(nfp_prog, meta, ALU_OP_XOR, !meta->insn.imm);
}

static int and_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu64_reg(nfp_prog, meta, ALU_OP_AND);
}

static int and_imm64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu64_imm(nfp_prog, meta, ALU_OP_AND, !~meta->insn.imm);
}

static int or_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu64_reg(nfp_prog, meta, ALU_OP_OR);
}

static int or_imm64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu64_imm(nfp_prog, meta, ALU_OP_OR, !meta->insn.imm);
}

static int add_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        emit_alu(nfp_prog, reg_both(insn->dst_reg * 2),
                 reg_a(insn->dst_reg * 2), ALU_OP_ADD,
                 reg_b(insn->src_reg * 2));
        emit_alu(nfp_prog, reg_both(insn->dst_reg * 2 + 1),
                 reg_a(insn->dst_reg * 2 + 1), ALU_OP_ADD_C,
                 reg_b(insn->src_reg * 2 + 1));

        return 0;
}

static int add_imm64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;
        u64 imm = insn->imm; /* sign extend */

        wrp_alu_imm(nfp_prog, insn->dst_reg * 2, ALU_OP_ADD, imm & ~0U);
        wrp_alu_imm(nfp_prog, insn->dst_reg * 2 + 1, ALU_OP_ADD_C, imm >> 32);

        return 0;
}

static int sub_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        emit_alu(nfp_prog, reg_both(insn->dst_reg * 2),
                 reg_a(insn->dst_reg * 2), ALU_OP_SUB,
                 reg_b(insn->src_reg * 2));
        emit_alu(nfp_prog, reg_both(insn->dst_reg * 2 + 1),
                 reg_a(insn->dst_reg * 2 + 1), ALU_OP_SUB_C,
                 reg_b(insn->src_reg * 2 + 1));

        return 0;
}

static int sub_imm64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;
        u64 imm = insn->imm; /* sign extend */

        wrp_alu_imm(nfp_prog, insn->dst_reg * 2, ALU_OP_SUB, imm & ~0U);
        wrp_alu_imm(nfp_prog, insn->dst_reg * 2 + 1, ALU_OP_SUB_C, imm >> 32);

        return 0;
}

static int shl_imm64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        if (insn->imm != 32)
                return 1; /* TODO */

        wrp_reg_mov(nfp_prog, insn->dst_reg * 2 + 1, insn->dst_reg * 2);
        wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2), 0);

        return 0;
}

static int shr_imm64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        if (insn->imm != 32)
                return 1; /* TODO */

        wrp_reg_mov(nfp_prog, insn->dst_reg * 2, insn->dst_reg * 2 + 1);
        wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2 + 1), 0);

        return 0;
}

static int mov_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        wrp_reg_mov(nfp_prog, insn->dst_reg * 2,  insn->src_reg * 2);
        wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2 + 1), 0);

        return 0;
}

static int mov_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2), insn->imm);
        wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2 + 1), 0);

        return 0;
}

static int xor_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_reg(nfp_prog, meta, ALU_OP_XOR);
}

static int xor_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_imm(nfp_prog, meta, ALU_OP_XOR, !~meta->insn.imm);
}

static int and_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_reg(nfp_prog, meta, ALU_OP_AND);
}

static int and_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_imm(nfp_prog, meta, ALU_OP_AND, !~meta->insn.imm);
}

static int or_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_reg(nfp_prog, meta, ALU_OP_OR);
}

static int or_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_imm(nfp_prog, meta, ALU_OP_OR, !meta->insn.imm);
}

static int add_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_reg(nfp_prog, meta, ALU_OP_ADD);
}

static int add_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_imm(nfp_prog, meta, ALU_OP_ADD, !meta->insn.imm);
}

static int sub_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_reg(nfp_prog, meta, ALU_OP_SUB);
}

static int sub_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_alu32_imm(nfp_prog, meta, ALU_OP_SUB, !meta->insn.imm);
}

static int shl_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        if (!insn->imm)
                return 1; /* TODO: zero shift means indirect */

        emit_shf(nfp_prog, reg_both(insn->dst_reg * 2),
                 reg_none(), SHF_OP_NONE, reg_b(insn->dst_reg * 2),
                 SHF_SC_L_SHF, insn->imm);
        wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2 + 1), 0);

        return 0;
}

static int imm_ld8_part2(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        wrp_immed(nfp_prog, reg_both(nfp_meta_prev(meta)->insn.dst_reg * 2 + 1),
                  meta->insn.imm);

        return 0;
}

static int imm_ld8(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        meta->double_cb = imm_ld8_part2;
        wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2), insn->imm);

        return 0;
}

static int data_ld1(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return construct_data_ld(nfp_prog, meta->insn.imm, 1);
}

static int data_ld2(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return construct_data_ld(nfp_prog, meta->insn.imm, 2);
}

static int data_ld4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return construct_data_ld(nfp_prog, meta->insn.imm, 4);
}

static int data_ind_ld1(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return construct_data_ind_ld(nfp_prog, meta->insn.imm,
                                     meta->insn.src_reg * 2, true, 1);
}

static int data_ind_ld2(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return construct_data_ind_ld(nfp_prog, meta->insn.imm,
                                     meta->insn.src_reg * 2, true, 2);
}

static int data_ind_ld4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return construct_data_ind_ld(nfp_prog, meta->insn.imm,
                                     meta->insn.src_reg * 2, true, 4);
}

static int mem_ldx4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        if (meta->insn.off == offsetof(struct sk_buff, len))
                emit_alu(nfp_prog, reg_both(meta->insn.dst_reg * 2),
                         reg_none(), ALU_OP_NONE, NFP_BPF_ABI_LEN);
        else
                return -ENOTSUPP;

        wrp_immed(nfp_prog, reg_both(meta->insn.dst_reg * 2 + 1), 0);

        return 0;
}

static int mem_stx4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        if (meta->insn.off == offsetof(struct sk_buff, mark))
                return wrp_set_mark(nfp_prog, meta->insn.src_reg * 2);

        return -ENOTSUPP;
}

static int jump(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        if (meta->insn.off < 0) /* TODO */
                return -ENOTSUPP;
        emit_br(nfp_prog, BR_UNC, meta->insn.off, 0);

        return 0;
}

static int jeq_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;
        u64 imm = insn->imm; /* sign extend */
        u32 or1 = reg_a(insn->dst_reg * 2), or2 = reg_b(insn->dst_reg * 2 + 1);
        u32 tmp_reg;

        if (insn->off < 0) /* TODO */
                return -ENOTSUPP;

        if (imm & ~0U) {
                tmp_reg = ur_load_imm_any(nfp_prog, imm & ~0U, imm_b(nfp_prog));
                emit_alu(nfp_prog, imm_a(nfp_prog),
                         reg_a(insn->dst_reg * 2), ALU_OP_XOR, tmp_reg);
                or1 = imm_a(nfp_prog);
        }

        if (imm >> 32) {
                tmp_reg = ur_load_imm_any(nfp_prog, imm >> 32, imm_b(nfp_prog));
                emit_alu(nfp_prog, imm_b(nfp_prog),
                         reg_a(insn->dst_reg * 2 + 1), ALU_OP_XOR, tmp_reg);
                or2 = imm_b(nfp_prog);
        }

        emit_alu(nfp_prog, reg_none(), or1, ALU_OP_OR, or2);
        emit_br(nfp_prog, BR_BEQ, insn->off, 0);

        return 0;
}

static int jgt_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_cmp_imm(nfp_prog, meta, BR_BLO, false);
}

static int jge_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_cmp_imm(nfp_prog, meta, BR_BHS, true);
}

static int jset_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;
        u64 imm = insn->imm; /* sign extend */
        u32 tmp_reg;

        if (insn->off < 0) /* TODO */
                return -ENOTSUPP;

        if (!imm) {
                meta->skip = true;
                return 0;
        }

        if (imm & ~0U) {
                tmp_reg = ur_load_imm_any(nfp_prog, imm & ~0U, imm_b(nfp_prog));
                emit_alu(nfp_prog, reg_none(),
                         reg_a(insn->dst_reg * 2), ALU_OP_AND, tmp_reg);
                emit_br(nfp_prog, BR_BNE, insn->off, 0);
        }

        if (imm >> 32) {
                tmp_reg = ur_load_imm_any(nfp_prog, imm >> 32, imm_b(nfp_prog));
                emit_alu(nfp_prog, reg_none(),
                         reg_a(insn->dst_reg * 2 + 1), ALU_OP_AND, tmp_reg);
                emit_br(nfp_prog, BR_BNE, insn->off, 0);
        }

        return 0;
}

static int jne_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;
        u64 imm = insn->imm; /* sign extend */
        u32 tmp_reg;

        if (insn->off < 0) /* TODO */
                return -ENOTSUPP;

        if (!imm) {
                emit_alu(nfp_prog, reg_none(), reg_a(insn->dst_reg * 2),
                         ALU_OP_OR, reg_b(insn->dst_reg * 2 + 1));
                emit_br(nfp_prog, BR_BNE, insn->off, 0);
        }

        tmp_reg = ur_load_imm_any(nfp_prog, imm & ~0U, imm_b(nfp_prog));
        emit_alu(nfp_prog, reg_none(),
                 reg_a(insn->dst_reg * 2), ALU_OP_XOR, tmp_reg);
        emit_br(nfp_prog, BR_BNE, insn->off, 0);

        tmp_reg = ur_load_imm_any(nfp_prog, imm >> 32, imm_b(nfp_prog));
        emit_alu(nfp_prog, reg_none(),
                 reg_a(insn->dst_reg * 2 + 1), ALU_OP_XOR, tmp_reg);
        emit_br(nfp_prog, BR_BNE, insn->off, 0);

        return 0;
}

static int jeq_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        const struct bpf_insn *insn = &meta->insn;

        if (insn->off < 0) /* TODO */
                return -ENOTSUPP;

        emit_alu(nfp_prog, imm_a(nfp_prog), reg_a(insn->dst_reg * 2),
                 ALU_OP_XOR, reg_b(insn->src_reg * 2));
        emit_alu(nfp_prog, imm_b(nfp_prog), reg_a(insn->dst_reg * 2 + 1),
                 ALU_OP_XOR, reg_b(insn->src_reg * 2 + 1));
        emit_alu(nfp_prog, reg_none(),
                 imm_a(nfp_prog), ALU_OP_OR, imm_b(nfp_prog));
        emit_br(nfp_prog, BR_BEQ, insn->off, 0);

        return 0;
}

static int jgt_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_cmp_reg(nfp_prog, meta, BR_BLO, false);
}

static int jge_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_cmp_reg(nfp_prog, meta, BR_BHS, true);
}

static int jset_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_test_reg(nfp_prog, meta, ALU_OP_AND, BR_BNE);
}

static int jne_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        return wrp_test_reg(nfp_prog, meta, ALU_OP_XOR, BR_BNE);
}

static int goto_out(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
        wrp_br_special(nfp_prog, BR_UNC, OP_BR_GO_OUT);

        return 0;
}

static const instr_cb_t instr_cb[256] = {
        [BPF_ALU64 | BPF_MOV | BPF_X] = mov_reg64,
        [BPF_ALU64 | BPF_MOV | BPF_K] = mov_imm64,
        [BPF_ALU64 | BPF_XOR | BPF_X] = xor_reg64,
        [BPF_ALU64 | BPF_XOR | BPF_K] = xor_imm64,
        [BPF_ALU64 | BPF_AND | BPF_X] = and_reg64,
        [BPF_ALU64 | BPF_AND | BPF_K] = and_imm64,
        [BPF_ALU64 | BPF_OR | BPF_X] =  or_reg64,
        [BPF_ALU64 | BPF_OR | BPF_K] =  or_imm64,
        [BPF_ALU64 | BPF_ADD | BPF_X] = add_reg64,
        [BPF_ALU64 | BPF_ADD | BPF_K] = add_imm64,
        [BPF_ALU64 | BPF_SUB | BPF_X] = sub_reg64,
        [BPF_ALU64 | BPF_SUB | BPF_K] = sub_imm64,
        [BPF_ALU64 | BPF_LSH | BPF_K] = shl_imm64,
        [BPF_ALU64 | BPF_RSH | BPF_K] = shr_imm64,
        [BPF_ALU | BPF_MOV | BPF_X] =   mov_reg,
        [BPF_ALU | BPF_MOV | BPF_K] =   mov_imm,
        [BPF_ALU | BPF_XOR | BPF_X] =   xor_reg,
        [BPF_ALU | BPF_XOR | BPF_K] =   xor_imm,
        [BPF_ALU | BPF_AND | BPF_X] =   and_reg,
        [BPF_ALU | BPF_AND | BPF_K] =   and_imm,
        [BPF_ALU | BPF_OR | BPF_X] =    or_reg,
        [BPF_ALU | BPF_OR | BPF_K] =    or_imm,
        [BPF_ALU | BPF_ADD | BPF_X] =   add_reg,
        [BPF_ALU | BPF_ADD | BPF_K] =   add_imm,
        [BPF_ALU | BPF_SUB | BPF_X] =   sub_reg,
        [BPF_ALU | BPF_SUB | BPF_K] =   sub_imm,
        [BPF_ALU | BPF_LSH | BPF_K] =   shl_imm,
        [BPF_LD | BPF_IMM | BPF_DW] =   imm_ld8,
        [BPF_LD | BPF_ABS | BPF_B] =    data_ld1,
        [BPF_LD | BPF_ABS | BPF_H] =    data_ld2,
        [BPF_LD | BPF_ABS | BPF_W] =    data_ld4,
        [BPF_LD | BPF_IND | BPF_B] =    data_ind_ld1,
        [BPF_LD | BPF_IND | BPF_H] =    data_ind_ld2,
        [BPF_LD | BPF_IND | BPF_W] =    data_ind_ld4,
        [BPF_LDX | BPF_MEM | BPF_W] =   mem_ldx4,
        [BPF_STX | BPF_MEM | BPF_W] =   mem_stx4,
        [BPF_JMP | BPF_JA | BPF_K] =    jump,
        [BPF_JMP | BPF_JEQ | BPF_K] =   jeq_imm,
        [BPF_JMP | BPF_JGT | BPF_K] =   jgt_imm,
        [BPF_JMP | BPF_JGE | BPF_K] =   jge_imm,
        [BPF_JMP | BPF_JSET | BPF_K] =  jset_imm,
        [BPF_JMP | BPF_JNE | BPF_K] =   jne_imm,
        [BPF_JMP | BPF_JEQ | BPF_X] =   jeq_reg,
        [BPF_JMP | BPF_JGT | BPF_X] =   jgt_reg,
        [BPF_JMP | BPF_JGE | BPF_X] =   jge_reg,
        [BPF_JMP | BPF_JSET | BPF_X] =  jset_reg,
        [BPF_JMP | BPF_JNE | BPF_X] =   jne_reg,
        [BPF_JMP | BPF_EXIT] =          goto_out,
};

/* --- Misc code --- */
static void br_set_offset(u64 *instr, u16 offset)
{
        u16 addr_lo, addr_hi;

        addr_lo = offset & (OP_BR_ADDR_LO >> __bf_shf(OP_BR_ADDR_LO));
        addr_hi = offset != addr_lo;
        *instr &= ~(OP_BR_ADDR_HI | OP_BR_ADDR_LO);
        *instr |= FIELD_PREP(OP_BR_ADDR_HI, addr_hi);
        *instr |= FIELD_PREP(OP_BR_ADDR_LO, addr_lo);
}

/* --- Assembler logic --- */
static int nfp_fixup_branches(struct nfp_prog *nfp_prog)
{
        struct nfp_insn_meta *meta, *next;
        u32 off, br_idx;
        u32 idx;

        nfp_for_each_insn_walk2(nfp_prog, meta, next) {
                if (meta->skip)
                        continue;
                if (BPF_CLASS(meta->insn.code) != BPF_JMP)
                        continue;

                br_idx = nfp_prog_offset_to_index(nfp_prog, next->off) - 1;
                if (!nfp_is_br(nfp_prog->prog[br_idx])) {
                        pr_err("Fixup found block not ending in branch %d %02x %016llx!!\n",
                               br_idx, meta->insn.code, nfp_prog->prog[br_idx]);
                        return -ELOOP;
                }
                /* Leave special branches for later */
                if (FIELD_GET(OP_BR_SPECIAL, nfp_prog->prog[br_idx]))
                        continue;

                /* Find the target offset in assembler realm */
                off = meta->insn.off;
                if (!off) {
                        pr_err("Fixup found zero offset!!\n");
                        return -ELOOP;
                }

                while (off && nfp_meta_has_next(nfp_prog, next)) {
                        next = nfp_meta_next(next);
                        off--;
                }
                if (off) {
                        pr_err("Fixup found too large jump!! %d\n", off);
                        return -ELOOP;
                }

                if (next->skip) {
                        pr_err("Branch landing on removed instruction!!\n");
                        return -ELOOP;
                }

                for (idx = nfp_prog_offset_to_index(nfp_prog, meta->off);
                     idx <= br_idx; idx++) {
                        if (!nfp_is_br(nfp_prog->prog[idx]))
                                continue;
                        br_set_offset(&nfp_prog->prog[idx], next->off);
                }
        }

        /* Fixup 'goto out's separately, they can be scattered around */
        for (br_idx = 0; br_idx < nfp_prog->prog_len; br_idx++) {
                enum br_special special;

                if ((nfp_prog->prog[br_idx] & OP_BR_BASE_MASK) != OP_BR_BASE)
                        continue;

                special = FIELD_GET(OP_BR_SPECIAL, nfp_prog->prog[br_idx]);
                switch (special) {
                case OP_BR_NORMAL:
                        break;
                case OP_BR_GO_OUT:
                        br_set_offset(&nfp_prog->prog[br_idx],
                                      nfp_prog->tgt_out);
                        break;
                case OP_BR_GO_ABORT:
                        br_set_offset(&nfp_prog->prog[br_idx],
                                      nfp_prog->tgt_abort);
                        break;
                }

                nfp_prog->prog[br_idx] &= ~OP_BR_SPECIAL;
        }

        return 0;
}

static void nfp_intro(struct nfp_prog *nfp_prog)
{
        emit_alu(nfp_prog, pkt_reg(nfp_prog),
                 reg_none(), ALU_OP_NONE, NFP_BPF_ABI_PKT);
}

static void nfp_outro_tc_legacy(struct nfp_prog *nfp_prog)
{
        const u8 act2code[] = {
                [NN_ACT_TC_DROP]  = 0x22,
                [NN_ACT_TC_REDIR] = 0x24
        };
        /* Target for aborts */
        nfp_prog->tgt_abort = nfp_prog_current_offset(nfp_prog);
        wrp_immed(nfp_prog, reg_both(0), 0);

        /* Target for normal exits */
        nfp_prog->tgt_out = nfp_prog_current_offset(nfp_prog);
        /* Legacy TC mode:
         *   0        0x11 -> pass,  count as stat0
         *  -1  drop  0x22 -> drop,  count as stat1
         *     redir  0x24 -> redir, count as stat1
         *  ife mark  0x21 -> pass,  count as stat1
         *  ife + tx  0x24 -> redir, count as stat1
         */
        emit_br_byte_neq(nfp_prog, reg_b(0), 0xff, 0, nfp_prog->tgt_done, 2);
        emit_alu(nfp_prog, reg_a(0),
                 reg_none(), ALU_OP_NONE, NFP_BPF_ABI_FLAGS);
        emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_imm(0x11), SHF_SC_L_SHF, 16);

        emit_br(nfp_prog, BR_UNC, nfp_prog->tgt_done, 1);
        emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_imm(act2code[nfp_prog->act]),
                      SHF_SC_L_SHF, 16);
}

static void nfp_outro_tc_da(struct nfp_prog *nfp_prog)
{
        /* TC direct-action mode:
         *   0,1   ok        NOT SUPPORTED[1]
         *   2   drop  0x22 -> drop,  count as stat1
         *   4,5 nuke  0x02 -> drop
         *   7  redir  0x44 -> redir, count as stat2
         *   * unspec  0x11 -> pass,  count as stat0
         *
         * [1] We can't support OK and RECLASSIFY because we can't tell TC
         *     the exact decision made.  We are forced to support UNSPEC
         *     to handle aborts so that's the only one we handle for passing
         *     packets up the stack.
         */
        /* Target for aborts */
        nfp_prog->tgt_abort = nfp_prog_current_offset(nfp_prog);

        emit_br_def(nfp_prog, nfp_prog->tgt_done, 2);

        emit_alu(nfp_prog, reg_a(0),
                 reg_none(), ALU_OP_NONE, NFP_BPF_ABI_FLAGS);
        emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_imm(0x11), SHF_SC_L_SHF, 16);

        /* Target for normal exits */
        nfp_prog->tgt_out = nfp_prog_current_offset(nfp_prog);

        /* if R0 > 7 jump to abort */
        emit_alu(nfp_prog, reg_none(), reg_imm(7), ALU_OP_SUB, reg_b(0));
        emit_br(nfp_prog, BR_BLO, nfp_prog->tgt_abort, 0);
        emit_alu(nfp_prog, reg_a(0),
                 reg_none(), ALU_OP_NONE, NFP_BPF_ABI_FLAGS);

        wrp_immed(nfp_prog, reg_b(2), 0x41221211);
        wrp_immed(nfp_prog, reg_b(3), 0x41001211);

        emit_shf(nfp_prog, reg_a(1),
                 reg_none(), SHF_OP_NONE, reg_b(0), SHF_SC_L_SHF, 2);

        emit_alu(nfp_prog, reg_none(), reg_a(1), ALU_OP_OR, reg_imm(0));
        emit_shf(nfp_prog, reg_a(2),
                 reg_imm(0xf), SHF_OP_AND, reg_b(2), SHF_SC_R_SHF, 0);

        emit_alu(nfp_prog, reg_none(), reg_a(1), ALU_OP_OR, reg_imm(0));
        emit_shf(nfp_prog, reg_b(2),
                 reg_imm(0xf), SHF_OP_AND, reg_b(3), SHF_SC_R_SHF, 0);

        emit_br_def(nfp_prog, nfp_prog->tgt_done, 2);

        emit_shf(nfp_prog, reg_b(2),
                 reg_a(2), SHF_OP_OR, reg_b(2), SHF_SC_L_SHF, 4);
        emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_b(2), SHF_SC_L_SHF, 16);
}

static void nfp_outro(struct nfp_prog *nfp_prog)
{
        switch (nfp_prog->act) {
        case NN_ACT_DIRECT:
                nfp_outro_tc_da(nfp_prog);
                break;
        case NN_ACT_TC_DROP:
        case NN_ACT_TC_REDIR:
                nfp_outro_tc_legacy(nfp_prog);
                break;
        }
}

static int nfp_translate(struct nfp_prog *nfp_prog)
{
        struct nfp_insn_meta *meta;
        int err;

        nfp_intro(nfp_prog);
        if (nfp_prog->error)
                return nfp_prog->error;

        list_for_each_entry(meta, &nfp_prog->insns, l) {
                instr_cb_t cb = instr_cb[meta->insn.code];

                meta->off = nfp_prog_current_offset(nfp_prog);

                if (meta->skip) {
                        nfp_prog->n_translated++;
                        continue;
                }

                if (nfp_meta_has_prev(nfp_prog, meta) &&
                    nfp_meta_prev(meta)->double_cb)
                        cb = nfp_meta_prev(meta)->double_cb;
                if (!cb)
                        return -ENOENT;
                err = cb(nfp_prog, meta);
                if (err)
                        return err;

                nfp_prog->n_translated++;
        }

        nfp_outro(nfp_prog);
        if (nfp_prog->error)
                return nfp_prog->error;

        return nfp_fixup_branches(nfp_prog);
}

static int
nfp_prog_prepare(struct nfp_prog *nfp_prog, const struct bpf_insn *prog,
                 unsigned int cnt)
{
        unsigned int i;

        for (i = 0; i < cnt; i++) {
                struct nfp_insn_meta *meta;

                meta = kzalloc(sizeof(*meta), GFP_KERNEL);
                if (!meta)
                        return -ENOMEM;

                meta->insn = prog[i];
                meta->n = i;

                list_add_tail(&meta->l, &nfp_prog->insns);
        }

        return 0;
}

/* --- Optimizations --- */
static void nfp_bpf_opt_reg_init(struct nfp_prog *nfp_prog)
{
        struct nfp_insn_meta *meta;

        list_for_each_entry(meta, &nfp_prog->insns, l) {
                struct bpf_insn insn = meta->insn;

                /* Programs converted from cBPF start with register xoring */
                if (insn.code == (BPF_ALU64 | BPF_XOR | BPF_X) &&
                    insn.src_reg == insn.dst_reg)
                        continue;

                /* Programs start with R6 = R1 but we ignore the skb pointer */
                if (insn.code == (BPF_ALU64 | BPF_MOV | BPF_X) &&
                    insn.src_reg == 1 && insn.dst_reg == 6)
                        meta->skip = true;

                /* Return as soon as something doesn't match */
                if (!meta->skip)
                        return;
        }
}

/* Try to rename registers so that program uses only low ones */
static int nfp_bpf_opt_reg_rename(struct nfp_prog *nfp_prog)
{
        bool reg_used[MAX_BPF_REG] = {};
        u8 tgt_reg[MAX_BPF_REG] = {};
        struct nfp_insn_meta *meta;
        unsigned int i, j;

        list_for_each_entry(meta, &nfp_prog->insns, l) {
                if (meta->skip)
                        continue;

                reg_used[meta->insn.src_reg] = true;
                reg_used[meta->insn.dst_reg] = true;
        }

        for (i = 0, j = 0; i < ARRAY_SIZE(tgt_reg); i++) {
                if (!reg_used[i])
                        continue;

                tgt_reg[i] = j++;
        }
        nfp_prog->num_regs = j;

        list_for_each_entry(meta, &nfp_prog->insns, l) {
                meta->insn.src_reg = tgt_reg[meta->insn.src_reg];
                meta->insn.dst_reg = tgt_reg[meta->insn.dst_reg];
        }

        return 0;
}

/* Remove masking after load since our load guarantees this is not needed */
static void nfp_bpf_opt_ld_mask(struct nfp_prog *nfp_prog)
{
        struct nfp_insn_meta *meta1, *meta2;
        const s32 exp_mask[] = {
                [BPF_B] = 0x000000ffU,
                [BPF_H] = 0x0000ffffU,
                [BPF_W] = 0xffffffffU,
        };

        nfp_for_each_insn_walk2(nfp_prog, meta1, meta2) {
                struct bpf_insn insn, next;

                insn = meta1->insn;
                next = meta2->insn;

                if (BPF_CLASS(insn.code) != BPF_LD)
                        continue;
                if (BPF_MODE(insn.code) != BPF_ABS &&
                    BPF_MODE(insn.code) != BPF_IND)
                        continue;

                if (next.code != (BPF_ALU64 | BPF_AND | BPF_K))
                        continue;

                if (!exp_mask[BPF_SIZE(insn.code)])
                        continue;
                if (exp_mask[BPF_SIZE(insn.code)] != next.imm)
                        continue;

                if (next.src_reg || next.dst_reg)
                        continue;

                meta2->skip = true;
        }
}

static void nfp_bpf_opt_ld_shift(struct nfp_prog *nfp_prog)
{
        struct nfp_insn_meta *meta1, *meta2, *meta3;

        nfp_for_each_insn_walk3(nfp_prog, meta1, meta2, meta3) {
                struct bpf_insn insn, next1, next2;

                insn = meta1->insn;
                next1 = meta2->insn;
                next2 = meta3->insn;

                if (BPF_CLASS(insn.code) != BPF_LD)
                        continue;
                if (BPF_MODE(insn.code) != BPF_ABS &&
                    BPF_MODE(insn.code) != BPF_IND)
                        continue;
                if (BPF_SIZE(insn.code) != BPF_W)
                        continue;

                if (!(next1.code == (BPF_LSH | BPF_K | BPF_ALU64) &&
                      next2.code == (BPF_RSH | BPF_K | BPF_ALU64)) &&
                    !(next1.code == (BPF_RSH | BPF_K | BPF_ALU64) &&
                      next2.code == (BPF_LSH | BPF_K | BPF_ALU64)))
                        continue;

                if (next1.src_reg || next1.dst_reg ||
                    next2.src_reg || next2.dst_reg)
                        continue;

                if (next1.imm != 0x20 || next2.imm != 0x20)
                        continue;

                meta2->skip = true;
                meta3->skip = true;
        }
}

static int nfp_bpf_optimize(struct nfp_prog *nfp_prog)
{
        int ret;

        nfp_bpf_opt_reg_init(nfp_prog);

        ret = nfp_bpf_opt_reg_rename(nfp_prog);
        if (ret)
                return ret;

        nfp_bpf_opt_ld_mask(nfp_prog);
        nfp_bpf_opt_ld_shift(nfp_prog);

        return 0;
}

/**
 * nfp_bpf_jit() - translate BPF code into NFP assembly
 * @filter:     kernel BPF filter struct
 * @prog_mem:   memory to store assembler instructions
 * @act:        action attached to this eBPF program
 * @prog_start: offset of the first instruction when loaded
 * @prog_done:  where to jump on exit
 * @prog_sz:    size of @prog_mem in instructions
 * @res:        achieved parameters of translation results
 */
int
nfp_bpf_jit(struct bpf_prog *filter, void *prog_mem,
            enum nfp_bpf_action_type act,
            unsigned int prog_start, unsigned int prog_done,
            unsigned int prog_sz, struct nfp_bpf_result *res)
{
        struct nfp_prog *nfp_prog;
        int ret;

        nfp_prog = kzalloc(sizeof(*nfp_prog), GFP_KERNEL);
        if (!nfp_prog)
                return -ENOMEM;

        INIT_LIST_HEAD(&nfp_prog->insns);
        nfp_prog->act = act;
        nfp_prog->start_off = prog_start;
        nfp_prog->tgt_done = prog_done;

        ret = nfp_prog_prepare(nfp_prog, filter->insnsi, filter->len);
        if (ret)
                goto out;

        ret = nfp_prog_verify(nfp_prog, filter);
        if (ret)
                goto out;

        ret = nfp_bpf_optimize(nfp_prog);
        if (ret)
                goto out;

        if (nfp_prog->num_regs <= 7)
                nfp_prog->regs_per_thread = 16;
        else
                nfp_prog->regs_per_thread = 32;

        nfp_prog->prog = prog_mem;
        nfp_prog->__prog_alloc_len = prog_sz;

        ret = nfp_translate(nfp_prog);
        if (ret) {
                pr_err("Translation failed with error %d (translated: %u)\n",
                       ret, nfp_prog->n_translated);
                ret = -EINVAL;
        }

        res->n_instr = nfp_prog->prog_len;
        res->dense_mode = nfp_prog->num_regs <= 7;
out:
        nfp_prog_free(nfp_prog);

        return ret;
}