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 | /* |
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 | |
20 | static unsigned long als[] = { FACILITIES_ALS }; |
21 | |
22 | static void u16_to_hex(char *str, u16 val) |
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 | |
35 | static void print_machine_type(void) |
36 | { |
37 | static char mach_str[80] = "Detected machine-type number: " ; |
38 | char type_str[5]; |
39 | struct cpuid id; |
40 | |
41 | get_cpu_id(&id); |
42 | u16_to_hex(str: type_str, val: id.machine); |
43 | strcat(p: mach_str, q: type_str); |
44 | strcat(p: mach_str, q: "\n" ); |
45 | sclp_early_printk(mach_str); |
46 | } |
47 | |
48 | static void u16_to_decimal(char *str, u16 val) |
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 | |
62 | void print_missing_facilities(void) |
63 | { |
64 | static char als_str[80] = "Missing facilities: " ; |
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 = ~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) { |
83 | strcat(als_str, "\n" ); |
84 | sclp_early_printk(als_str); |
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 | } |
92 | strcat(p: als_str, q: "\n" ); |
93 | sclp_early_printk(als_str); |
94 | } |
95 | |
96 | static void facility_mismatch(void) |
97 | { |
98 | sclp_early_printk("The Linux kernel requires more recent processor hardware\n" ); |
99 | print_machine_type(); |
100 | print_missing_facilities(); |
101 | sclp_early_printk("See Principles of Operations for facility bits\n" ); |
102 | disabled_wait(); |
103 | } |
104 | |
105 | void verify_facilities(void) |
106 | { |
107 | int i; |
108 | |
109 | __stfle(stfle_fac_list, ARRAY_SIZE(stfle_fac_list)); |
110 | for (i = 0; i < ARRAY_SIZE(als); i++) { |
111 | if ((stfle_fac_list[i] & als[i]) != als[i]) |
112 | facility_mismatch(); |
113 | } |
114 | } |
115 | |