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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
be2412c2 HC |
2 | /* |
3 | * Copyright IBM Corp. 2016 | |
4 | */ | |
5 | #include <linux/kernel.h> | |
be2412c2 HC |
6 | #include <asm/processor.h> |
7 | #include <asm/facility.h> | |
8 | #include <asm/lowcore.h> | |
9 | #include <asm/sclp.h> | |
6d85dac2 | 10 | #include "boot.h" |
be2412c2 HC |
11 | |
12 | /* | |
13 | * The code within this file will be called very early. It may _not_ | |
14 | * access anything within the bss section, since that is not cleared | |
15 | * yet and may contain data (e.g. initrd) that must be saved by other | |
16 | * code. | |
17 | * For temporary objects the stack (16k) should be used. | |
18 | */ | |
19 | ||
2dd26659 | 20 | static unsigned long als[] = { FACILITIES_ALS }; |
be2412c2 | 21 | |
2dd26659 | 22 | static void u16_to_hex(char *str, u16 val) |
06ed5512 HC |
23 | { |
24 | int i, num; | |
25 | ||
26 | for (i = 1; i <= 4; i++) { | |
27 | num = (val >> (16 - 4 * i)) & 0xf; | |
28 | if (num >= 10) | |
29 | num += 7; | |
30 | *str++ = '0' + num; | |
31 | } | |
32 | *str = '\0'; | |
33 | } | |
34 | ||
2dd26659 | 35 | static void print_machine_type(void) |
06ed5512 | 36 | { |
2dd26659 | 37 | static char mach_str[80] = "Detected machine-type number: "; |
06ed5512 HC |
38 | char type_str[5]; |
39 | struct cpuid id; | |
40 | ||
41 | get_cpu_id(&id); | |
42 | u16_to_hex(type_str, id.machine); | |
43 | strcat(mach_str, type_str); | |
02407baa | 44 | strcat(mach_str, "\n"); |
d5ab7a34 | 45 | sclp_early_printk(mach_str); |
06ed5512 HC |
46 | } |
47 | ||
2dd26659 | 48 | static void u16_to_decimal(char *str, u16 val) |
a02d1988 HC |
49 | { |
50 | int div = 1; | |
51 | ||
52 | while (div * 10 <= val) | |
53 | div *= 10; | |
54 | while (div) { | |
55 | *str++ = '0' + val / div; | |
56 | val %= div; | |
57 | div /= 10; | |
58 | } | |
59 | *str = '\0'; | |
60 | } | |
61 | ||
6d85dac2 | 62 | void print_missing_facilities(void) |
a02d1988 | 63 | { |
2dd26659 | 64 | static char als_str[80] = "Missing facilities: "; |
a02d1988 HC |
65 | unsigned long val; |
66 | char val_str[6]; | |
67 | int i, j, first; | |
68 | ||
69 | first = 1; | |
70 | for (i = 0; i < ARRAY_SIZE(als); i++) { | |
71 | val = ~S390_lowcore.stfle_fac_list[i] & als[i]; | |
72 | for (j = 0; j < BITS_PER_LONG; j++) { | |
73 | if (!(val & (1UL << (BITS_PER_LONG - 1 - j)))) | |
74 | continue; | |
75 | if (!first) | |
76 | strcat(als_str, ","); | |
77 | /* | |
78 | * Make sure we stay within one line. Consider that | |
79 | * each facility bit adds up to five characters and | |
80 | * z/VM adds a four character prefix. | |
81 | */ | |
82 | if (strlen(als_str) > 70) { | |
02407baa | 83 | strcat(als_str, "\n"); |
d5ab7a34 | 84 | sclp_early_printk(als_str); |
a02d1988 HC |
85 | *als_str = '\0'; |
86 | } | |
87 | u16_to_decimal(val_str, i * BITS_PER_LONG + j); | |
88 | strcat(als_str, val_str); | |
89 | first = 0; | |
90 | } | |
91 | } | |
02407baa | 92 | strcat(als_str, "\n"); |
d5ab7a34 | 93 | sclp_early_printk(als_str); |
a02d1988 HC |
94 | } |
95 | ||
2dd26659 | 96 | static void facility_mismatch(void) |
06ed5512 | 97 | { |
02407baa | 98 | sclp_early_printk("The Linux kernel requires more recent processor hardware\n"); |
06ed5512 | 99 | print_machine_type(); |
a02d1988 | 100 | print_missing_facilities(); |
6d85dac2 | 101 | sclp_early_printk("See Principles of Operations for facility bits\n"); |
98587c2d | 102 | disabled_wait(); |
06ed5512 HC |
103 | } |
104 | ||
2dd26659 | 105 | void verify_facilities(void) |
be2412c2 HC |
106 | { |
107 | int i; | |
108 | ||
96d3b64b | 109 | __stfle(S390_lowcore.stfle_fac_list, ARRAY_SIZE(S390_lowcore.stfle_fac_list)); |
be2412c2 | 110 | for (i = 0; i < ARRAY_SIZE(als); i++) { |
06ed5512 HC |
111 | if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i]) |
112 | facility_mismatch(); | |
be2412c2 HC |
113 | } |
114 | } |