arch/s390/kernel/ipl_vmparm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/minmax.h>
   3 #include <linux/string.h>
   4 #include <asm/ebcdic.h>
   5 #include <asm/ipl.h>
   6
   7 /* VM IPL PARM routines */
   8 size_t ipl_block_get_ascii_vmparm(char *dest, size_t size,
   9                                   const struct ipl_parameter_block *ipb)
  10 {
  11         int i;
  12         size_t len;
  13         char has_lowercase = 0;
  14
  15         len = 0;
  16         if ((ipb->ccw.vm_flags & IPL_PB0_CCW_VM_FLAG_VP) &&
  17             (ipb->ccw.vm_parm_len > 0)) {
  18
  19                 len = min_t(size_t, size - 1, ipb->ccw.vm_parm_len);
  20                 memcpy(dest, ipb->ccw.vm_parm, len);
  21                 /* If at least one character is lowercase, we assume mixed
  22                  * case; otherwise we convert everything to lowercase.
  23                  */
  24                 for (i = 0; i < len; i++)
  25                         if ((dest[i] > 0x80 && dest[i] < 0x8a) || /* a-i */
  26                             (dest[i] > 0x90 && dest[i] < 0x9a) || /* j-r */
  27                             (dest[i] > 0xa1 && dest[i] < 0xaa)) { /* s-z */
  28                                 has_lowercase = 1;
  29                                 break;
  30                         }
  31                 if (!has_lowercase)
  32                         EBC_TOLOWER(dest, len);
  33                 EBCASC(dest, len);
  34         }
  35         dest[len] = 0;
  36
  37         return len;
  38 }