xref: /linux/arch/s390/kernel/ipl_vmparm.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <asm/ebcdic.h>
3 #include <asm/ipl.h>
4 
5 /* VM IPL PARM routines */
6 size_t ipl_block_get_ascii_vmparm(char *dest, size_t size,
7 				  const struct ipl_parameter_block *ipb)
8 {
9 	int i;
10 	size_t len;
11 	char has_lowercase = 0;
12 
13 	len = 0;
14 	if ((ipb->ccw.vm_flags & IPL_PB0_CCW_VM_FLAG_VP) &&
15 	    (ipb->ccw.vm_parm_len > 0)) {
16 
17 		len = min_t(size_t, size - 1, ipb->ccw.vm_parm_len);
18 		memcpy(dest, ipb->ccw.vm_parm, len);
19 		/* If at least one character is lowercase, we assume mixed
20 		 * case; otherwise we convert everything to lowercase.
21 		 */
22 		for (i = 0; i < len; i++)
23 			if ((dest[i] > 0x80 && dest[i] < 0x8a) || /* a-i */
24 			    (dest[i] > 0x90 && dest[i] < 0x9a) || /* j-r */
25 			    (dest[i] > 0xa1 && dest[i] < 0xaa)) { /* s-z */
26 				has_lowercase = 1;
27 				break;
28 			}
29 		if (!has_lowercase)
30 			EBC_TOLOWER(dest, len);
31 		EBCASC(dest, len);
32 	}
33 	dest[len] = 0;
34 
35 	return len;
36 }
37