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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> | |
6 | #include <linux/init.h> | |
7 | #include <asm/processor.h> | |
8 | #include <asm/facility.h> | |
9 | #include <asm/lowcore.h> | |
10 | #include <asm/sclp.h> | |
11 | #include "entry.h" | |
12 | ||
13 | /* | |
14 | * The code within this file will be called very early. It may _not_ | |
15 | * access anything within the bss section, since that is not cleared | |
16 | * yet and may contain data (e.g. initrd) that must be saved by other | |
17 | * code. | |
18 | * For temporary objects the stack (16k) should be used. | |
19 | */ | |
20 | ||
21 | static unsigned long als[] __initdata = { FACILITIES_ALS }; | |
22 | ||
06ed5512 HC |
23 | static void __init u16_to_hex(char *str, u16 val) |
24 | { | |
25 | int i, num; | |
26 | ||
27 | for (i = 1; i <= 4; i++) { | |
28 | num = (val >> (16 - 4 * i)) & 0xf; | |
29 | if (num >= 10) | |
30 | num += 7; | |
31 | *str++ = '0' + num; | |
32 | } | |
33 | *str = '\0'; | |
34 | } | |
35 | ||
36 | static void __init print_machine_type(void) | |
37 | { | |
38 | static char mach_str[80] __initdata = "Detected machine-type number: "; | |
39 | char type_str[5]; | |
40 | struct cpuid id; | |
41 | ||
42 | get_cpu_id(&id); | |
43 | u16_to_hex(type_str, id.machine); | |
44 | strcat(mach_str, type_str); | |
02407baa | 45 | strcat(mach_str, "\n"); |
d5ab7a34 | 46 | sclp_early_printk(mach_str); |
06ed5512 HC |
47 | } |
48 | ||
a02d1988 HC |
49 | static void __init u16_to_decimal(char *str, u16 val) |
50 | { | |
51 | int div = 1; | |
52 | ||
53 | while (div * 10 <= val) | |
54 | div *= 10; | |
55 | while (div) { | |
56 | *str++ = '0' + val / div; | |
57 | val %= div; | |
58 | div /= 10; | |
59 | } | |
60 | *str = '\0'; | |
61 | } | |
62 | ||
63 | static void __init print_missing_facilities(void) | |
64 | { | |
65 | static char als_str[80] __initdata = "Missing facilities: "; | |
66 | unsigned long val; | |
67 | char val_str[6]; | |
68 | int i, j, first; | |
69 | ||
70 | first = 1; | |
71 | for (i = 0; i < ARRAY_SIZE(als); i++) { | |
72 | val = ~S390_lowcore.stfle_fac_list[i] & als[i]; | |
73 | for (j = 0; j < BITS_PER_LONG; j++) { | |
74 | if (!(val & (1UL << (BITS_PER_LONG - 1 - j)))) | |
75 | continue; | |
76 | if (!first) | |
77 | strcat(als_str, ","); | |
78 | /* | |
79 | * Make sure we stay within one line. Consider that | |
80 | * each facility bit adds up to five characters and | |
81 | * z/VM adds a four character prefix. | |
82 | */ | |
83 | if (strlen(als_str) > 70) { | |
02407baa | 84 | strcat(als_str, "\n"); |
d5ab7a34 | 85 | sclp_early_printk(als_str); |
a02d1988 HC |
86 | *als_str = '\0'; |
87 | } | |
88 | u16_to_decimal(val_str, i * BITS_PER_LONG + j); | |
89 | strcat(als_str, val_str); | |
90 | first = 0; | |
91 | } | |
92 | } | |
02407baa | 93 | strcat(als_str, "\n"); |
d5ab7a34 | 94 | sclp_early_printk(als_str); |
02407baa | 95 | sclp_early_printk("See Principles of Operations for facility bits\n"); |
a02d1988 HC |
96 | } |
97 | ||
06ed5512 HC |
98 | static void __init facility_mismatch(void) |
99 | { | |
02407baa | 100 | sclp_early_printk("The Linux kernel requires more recent processor hardware\n"); |
06ed5512 | 101 | print_machine_type(); |
a02d1988 | 102 | print_missing_facilities(); |
06ed5512 HC |
103 | disabled_wait(0x8badcccc); |
104 | } | |
105 | ||
be2412c2 HC |
106 | void __init verify_facilities(void) |
107 | { | |
108 | int i; | |
109 | ||
110 | for (i = 0; i < ARRAY_SIZE(S390_lowcore.stfle_fac_list); i++) | |
111 | S390_lowcore.stfle_fac_list[i] = 0; | |
112 | asm volatile( | |
113 | " stfl 0(0)\n" | |
114 | : "=m" (S390_lowcore.stfl_fac_list)); | |
115 | S390_lowcore.stfle_fac_list[0] = (u64)S390_lowcore.stfl_fac_list << 32; | |
116 | if (S390_lowcore.stfl_fac_list & 0x01000000) { | |
117 | register unsigned long reg0 asm("0") = ARRAY_SIZE(als) - 1; | |
118 | ||
119 | asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */ | |
120 | : "+d" (reg0) | |
121 | : "a" (&S390_lowcore.stfle_fac_list) | |
122 | : "memory", "cc"); | |
123 | } | |
124 | for (i = 0; i < ARRAY_SIZE(als); i++) { | |
06ed5512 HC |
125 | if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i]) |
126 | facility_mismatch(); | |
be2412c2 HC |
127 | } |
128 | } |