forked from Minki/linux
a02d1988b5
If the kernel needs more facilities to run than the machine provides it is running on, print the facility bit numbers which are missing. This allows to easily tell what went wrong and if simply the machine does not provide a required facility or if either the kernel or the hypervisor may have a bug. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
125 lines
2.9 KiB
C
125 lines
2.9 KiB
C
/*
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* Copyright IBM Corp. 2016
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <asm/processor.h>
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#include <asm/facility.h>
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#include <asm/lowcore.h>
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#include <asm/sclp.h>
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#include "entry.h"
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/*
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* The code within this file will be called very early. It may _not_
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* access anything within the bss section, since that is not cleared
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* yet and may contain data (e.g. initrd) that must be saved by other
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* code.
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* For temporary objects the stack (16k) should be used.
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*/
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static unsigned long als[] __initdata = { FACILITIES_ALS };
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static void __init u16_to_hex(char *str, u16 val)
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{
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int i, num;
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for (i = 1; i <= 4; i++) {
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num = (val >> (16 - 4 * i)) & 0xf;
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if (num >= 10)
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num += 7;
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*str++ = '0' + num;
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}
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*str = '\0';
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}
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static void __init print_machine_type(void)
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{
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static char mach_str[80] __initdata = "Detected machine-type number: ";
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char type_str[5];
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struct cpuid id;
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get_cpu_id(&id);
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u16_to_hex(type_str, id.machine);
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strcat(mach_str, type_str);
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_sclp_print_early(mach_str);
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}
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static void __init u16_to_decimal(char *str, u16 val)
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{
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int div = 1;
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while (div * 10 <= val)
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div *= 10;
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while (div) {
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*str++ = '0' + val / div;
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val %= div;
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div /= 10;
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}
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*str = '\0';
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}
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static void __init print_missing_facilities(void)
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{
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static char als_str[80] __initdata = "Missing facilities: ";
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unsigned long val;
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char val_str[6];
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int i, j, first;
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first = 1;
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for (i = 0; i < ARRAY_SIZE(als); i++) {
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val = ~S390_lowcore.stfle_fac_list[i] & als[i];
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for (j = 0; j < BITS_PER_LONG; j++) {
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if (!(val & (1UL << (BITS_PER_LONG - 1 - j))))
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continue;
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if (!first)
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strcat(als_str, ",");
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/*
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* Make sure we stay within one line. Consider that
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* each facility bit adds up to five characters and
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* z/VM adds a four character prefix.
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*/
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if (strlen(als_str) > 70) {
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_sclp_print_early(als_str);
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*als_str = '\0';
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}
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u16_to_decimal(val_str, i * BITS_PER_LONG + j);
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strcat(als_str, val_str);
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first = 0;
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}
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}
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_sclp_print_early(als_str);
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_sclp_print_early("See Principles of Operations for facility bits");
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}
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static void __init facility_mismatch(void)
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{
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_sclp_print_early("The Linux kernel requires more recent processor hardware");
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print_machine_type();
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print_missing_facilities();
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disabled_wait(0x8badcccc);
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}
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void __init verify_facilities(void)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(S390_lowcore.stfle_fac_list); i++)
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S390_lowcore.stfle_fac_list[i] = 0;
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asm volatile(
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" stfl 0(0)\n"
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: "=m" (S390_lowcore.stfl_fac_list));
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S390_lowcore.stfle_fac_list[0] = (u64)S390_lowcore.stfl_fac_list << 32;
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if (S390_lowcore.stfl_fac_list & 0x01000000) {
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register unsigned long reg0 asm("0") = ARRAY_SIZE(als) - 1;
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asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */
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: "+d" (reg0)
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: "a" (&S390_lowcore.stfle_fac_list)
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: "memory", "cc");
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}
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for (i = 0; i < ARRAY_SIZE(als); i++) {
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if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i])
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facility_mismatch();
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}
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}
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