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be2412c2 HC |
1 | /* |
2 | * Copyright IBM Corp. 2016 | |
3 | */ | |
4 | #include <linux/kernel.h> | |
5 | #include <linux/init.h> | |
6 | #include <asm/processor.h> | |
7 | #include <asm/facility.h> | |
8 | #include <asm/lowcore.h> | |
9 | #include <asm/sclp.h> | |
10 | #include "entry.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[] __initdata = { FACILITIES_ALS }; | |
21 | ||
06ed5512 HC |
22 | static void __init 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 __init print_machine_type(void) | |
36 | { | |
37 | static char mach_str[80] __initdata = "Detected machine-type number: "; | |
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); | |
44 | _sclp_print_early(mach_str); | |
45 | } | |
46 | ||
a02d1988 HC |
47 | static void __init u16_to_decimal(char *str, u16 val) |
48 | { | |
49 | int div = 1; | |
50 | ||
51 | while (div * 10 <= val) | |
52 | div *= 10; | |
53 | while (div) { | |
54 | *str++ = '0' + val / div; | |
55 | val %= div; | |
56 | div /= 10; | |
57 | } | |
58 | *str = '\0'; | |
59 | } | |
60 | ||
61 | static void __init print_missing_facilities(void) | |
62 | { | |
63 | static char als_str[80] __initdata = "Missing facilities: "; | |
64 | unsigned long val; | |
65 | char val_str[6]; | |
66 | int i, j, first; | |
67 | ||
68 | first = 1; | |
69 | for (i = 0; i < ARRAY_SIZE(als); i++) { | |
70 | val = ~S390_lowcore.stfle_fac_list[i] & als[i]; | |
71 | for (j = 0; j < BITS_PER_LONG; j++) { | |
72 | if (!(val & (1UL << (BITS_PER_LONG - 1 - j)))) | |
73 | continue; | |
74 | if (!first) | |
75 | strcat(als_str, ","); | |
76 | /* | |
77 | * Make sure we stay within one line. Consider that | |
78 | * each facility bit adds up to five characters and | |
79 | * z/VM adds a four character prefix. | |
80 | */ | |
81 | if (strlen(als_str) > 70) { | |
82 | _sclp_print_early(als_str); | |
83 | *als_str = '\0'; | |
84 | } | |
85 | u16_to_decimal(val_str, i * BITS_PER_LONG + j); | |
86 | strcat(als_str, val_str); | |
87 | first = 0; | |
88 | } | |
89 | } | |
90 | _sclp_print_early(als_str); | |
91 | _sclp_print_early("See Principles of Operations for facility bits"); | |
92 | } | |
93 | ||
06ed5512 HC |
94 | static void __init facility_mismatch(void) |
95 | { | |
96 | _sclp_print_early("The Linux kernel requires more recent processor hardware"); | |
97 | print_machine_type(); | |
a02d1988 | 98 | print_missing_facilities(); |
06ed5512 HC |
99 | disabled_wait(0x8badcccc); |
100 | } | |
101 | ||
be2412c2 HC |
102 | void __init verify_facilities(void) |
103 | { | |
104 | int i; | |
105 | ||
106 | for (i = 0; i < ARRAY_SIZE(S390_lowcore.stfle_fac_list); i++) | |
107 | S390_lowcore.stfle_fac_list[i] = 0; | |
108 | asm volatile( | |
109 | " stfl 0(0)\n" | |
110 | : "=m" (S390_lowcore.stfl_fac_list)); | |
111 | S390_lowcore.stfle_fac_list[0] = (u64)S390_lowcore.stfl_fac_list << 32; | |
112 | if (S390_lowcore.stfl_fac_list & 0x01000000) { | |
113 | register unsigned long reg0 asm("0") = ARRAY_SIZE(als) - 1; | |
114 | ||
115 | asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */ | |
116 | : "+d" (reg0) | |
117 | : "a" (&S390_lowcore.stfle_fac_list) | |
118 | : "memory", "cc"); | |
119 | } | |
120 | for (i = 0; i < ARRAY_SIZE(als); i++) { | |
06ed5512 HC |
121 | if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i]) |
122 | facility_mismatch(); | |
be2412c2 HC |
123 | } |
124 | } |