xref: /linux/arch/s390/boot/als.c (revision a0efa2f362a69e47b9d8b48f770ef3a0249a7911)
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 
12 static unsigned long als[] = { FACILITIES_ALS };
13 
14 static 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 
28 void 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 
60 static 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 
72 void 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 }
82