// SPDX-License-Identifier: GPL-2.0

#include <errno.h>
#include <regex.h>
#include "../perf_regs.h"
#include "../../arch/s390/include/perf_regs.h"
#include "debug.h"

#include <linux/zalloc.h>
#include <linux/kernel.h>

uint64_t __perf_reg_mask_s390(bool intr __maybe_unused)
{
        return PERF_REGS_MASK;
}

const char *__perf_reg_name_s390(int id)
{
        switch (id) {
        case PERF_REG_S390_R0:
                return "R0";
        case PERF_REG_S390_R1:
                return "R1";
        case PERF_REG_S390_R2:
                return "R2";
        case PERF_REG_S390_R3:
                return "R3";
        case PERF_REG_S390_R4:
                return "R4";
        case PERF_REG_S390_R5:
                return "R5";
        case PERF_REG_S390_R6:
                return "R6";
        case PERF_REG_S390_R7:
                return "R7";
        case PERF_REG_S390_R8:
                return "R8";
        case PERF_REG_S390_R9:
                return "R9";
        case PERF_REG_S390_R10:
                return "R10";
        case PERF_REG_S390_R11:
                return "R11";
        case PERF_REG_S390_R12:
                return "R12";
        case PERF_REG_S390_R13:
                return "R13";
        case PERF_REG_S390_R14:
                return "R14";
        case PERF_REG_S390_R15:
                return "R15";
        case PERF_REG_S390_FP0:
                return "FP0";
        case PERF_REG_S390_FP1:
                return "FP1";
        case PERF_REG_S390_FP2:
                return "FP2";
        case PERF_REG_S390_FP3:
                return "FP3";
        case PERF_REG_S390_FP4:
                return "FP4";
        case PERF_REG_S390_FP5:
                return "FP5";
        case PERF_REG_S390_FP6:
                return "FP6";
        case PERF_REG_S390_FP7:
                return "FP7";
        case PERF_REG_S390_FP8:
                return "FP8";
        case PERF_REG_S390_FP9:
                return "FP9";
        case PERF_REG_S390_FP10:
                return "FP10";
        case PERF_REG_S390_FP11:
                return "FP11";
        case PERF_REG_S390_FP12:
                return "FP12";
        case PERF_REG_S390_FP13:
                return "FP13";
        case PERF_REG_S390_FP14:
                return "FP14";
        case PERF_REG_S390_FP15:
                return "FP15";
        case PERF_REG_S390_MASK:
                return "MASK";
        case PERF_REG_S390_PC:
                return "PC";
        default:
                return NULL;
        }

        return NULL;
}

uint64_t __perf_reg_ip_s390(void)
{
        return PERF_REG_S390_PC;
}

uint64_t __perf_reg_sp_s390(void)
{
        return PERF_REG_S390_R15;
}

/* %rXX */
#define SDT_OP_REGEX1  "^(%r([0-9]|1[0-5]))$"
/* +-###(%rXX) */
#define SDT_OP_REGEX2  "^([+-]?[0-9]+\\(%r([0-9]|1[0-5])\\))$"
static regex_t sdt_op_regex1, sdt_op_regex2;

static int sdt_init_op_regex(void)
{
        static int initialized;
        int ret = 0;

        if (initialized)
                return 0;

        ret = regcomp(&sdt_op_regex1, SDT_OP_REGEX1, REG_EXTENDED);
        if (ret)
                goto error;
        initialized = 1;

        ret = regcomp(&sdt_op_regex2, SDT_OP_REGEX2, REG_EXTENDED);
        if (ret)
                goto free_regex1;
        initialized = 2;

        return 0;

free_regex1:
        regfree(&sdt_op_regex1);
error:
        pr_debug4("Regex compilation error, initialized %d\n", initialized);
        initialized = 0;
        return ret;
}

/*
 * Parse OP and convert it into uprobe format, which is, +/-NUM(%gprREG).
 * Possible variants of OP are:
 *      Format          Example
 *      -------------------------
 *      NUM(%rREG)      48(%r1)
 *      -NUM(%rREG)     -48(%r1)
 *      +NUM(%rREG)     +48(%r1)
 *      %rREG           %r1
 */
int __perf_sdt_arg_parse_op_s390(char *old_op, char **new_op)
{
        int ret, new_len;
        regmatch_t rm[6];

        *new_op = NULL;
        ret = sdt_init_op_regex();
        if (ret)
                return -EINVAL;

        if (!regexec(&sdt_op_regex1, old_op, ARRAY_SIZE(rm), rm, 0) ||
            !regexec(&sdt_op_regex2, old_op, ARRAY_SIZE(rm), rm, 0)) {
                new_len = 1;    /* NULL byte */
                new_len += (int)(rm[1].rm_eo - rm[1].rm_so);
                *new_op = zalloc(new_len);
                if (!*new_op)
                        return -ENOMEM;

                scnprintf(*new_op, new_len, "%.*s",
                          (int)(rm[1].rm_eo - rm[1].rm_so), old_op + rm[1].rm_so);
        } else {
                pr_debug4("Skipping unsupported SDT argument: %s\n", old_op);
                return SDT_ARG_SKIP;
        }

        return SDT_ARG_VALID;
}