1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 *    Copyright IBM Corp. 2016
 4 */
 5#include <linux/kernel.h>
 6#include <asm/processor.h>
 7#include <asm/facility.h>
 8#include <asm/lowcore.h>
 9#include <asm/sclp.h>
10#include "boot.h"
11
12static unsigned long als[] = { FACILITIES_ALS };
13
14static void u16_to_decimal(char *str, u16 val)
15{
16	int div = 1;
17
18	while (div * 10 <= val)
19		div *= 10;
20	while (div) {
21		*str++ = '0' + val / div;
22		val %= div;
23		div /= 10;
24	}
25	*str = '\0';
26}
27
28void print_missing_facilities(void)
29{
30	static char als_str[80] = "Missing facilities: ";
31	unsigned long val;
32	char val_str[6];
33	int i, j, first;
34
35	first = 1;
36	for (i = 0; i < ARRAY_SIZE(als); i++) {
37		val = ~stfle_fac_list[i] & als[i];
38		for (j = 0; j < BITS_PER_LONG; j++) {
39			if (!(val & (1UL << (BITS_PER_LONG - 1 - j))))
40				continue;
41			if (!first)
42				strcat(als_str, ",");
43			/*
44			 * Make sure we stay within one line. Consider that
45			 * each facility bit adds up to five characters and
46			 * z/VM adds a four character prefix.
47			 */
48			if (strlen(als_str) > 70) {
49				boot_printk("%s\n", als_str);
50				*als_str = '\0';
51			}
52			u16_to_decimal(val_str, i * BITS_PER_LONG + j);
53			strcat(als_str, val_str);
54			first = 0;
55		}
56	}
57	boot_printk("%s\n", als_str);
58}
59
60static void facility_mismatch(void)
61{
62	struct cpuid id;
63
64	get_cpu_id(&id);
65	boot_printk("The Linux kernel requires more recent processor hardware\n");
66	boot_printk("Detected machine-type number: %4x\n", id.machine);
67	print_missing_facilities();
68	boot_printk("See Principles of Operations for facility bits\n");
69	disabled_wait();
70}
71
72void verify_facilities(void)
73{
74	int i;
75
76	__stfle(stfle_fac_list, ARRAY_SIZE(stfle_fac_list));
77	for (i = 0; i < ARRAY_SIZE(als); i++) {
78		if ((stfle_fac_list[i] & als[i]) != als[i])
79			facility_mismatch();
80	}
81}