// SPDX-License-Identifier: GPL-2.0
#include <linux/minmax.h>
#include <linux/string.h>
#include <asm/ebcdic.h>
#include <asm/ipl.h>

/* VM IPL PARM routines */
size_t ipl_block_get_ascii_vmparm(char *dest, size_t size,
                                  const struct ipl_parameter_block *ipb)
{
        int i;
        size_t len;
        char has_lowercase = 0;

        len = 0;
        if ((ipb->ccw.vm_flags & IPL_PB0_CCW_VM_FLAG_VP) &&
            (ipb->ccw.vm_parm_len > 0)) {

                len = min_t(size_t, size - 1, ipb->ccw.vm_parm_len);
                memcpy(dest, ipb->ccw.vm_parm, len);
                /* If at least one character is lowercase, we assume mixed
                 * case; otherwise we convert everything to lowercase.
                 */
                for (i = 0; i < len; i++)
                        if ((dest[i] > 0x80 && dest[i] < 0x8a) || /* a-i */
                            (dest[i] > 0x90 && dest[i] < 0x9a) || /* j-r */
                            (dest[i] > 0xa1 && dest[i] < 0xaa)) { /* s-z */
                                has_lowercase = 1;
                                break;
                        }
                if (!has_lowercase)
                        EBC_TOLOWER(dest, len);
                EBCASC(dest, len);
        }
        dest[len] = 0;

        return len;
}