xref: /openbmc/linux/arch/s390/kernel/ipl_vmparm.c (revision 2cf1c348)
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 }
39