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/*
* Copyright IBM Corp. 2016
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/processor.h>
#include <asm/facility.h>
#include <asm/lowcore.h>
#include <asm/sclp.h>
#include "entry.h"
/*
* The code within this file will be called very early. It may _not_
* access anything within the bss section, since that is not cleared
* yet and may contain data (e.g. initrd) that must be saved by other
* code.
* For temporary objects the stack (16k) should be used.
*/
static unsigned long als[] __initdata = { FACILITIES_ALS };
static void __init u16_to_hex(char *str, u16 val)
{
int i, num;
for (i = 1; i <= 4; i++) {
num = (val >> (16 - 4 * i)) & 0xf;
if (num >= 10)
num += 7;
*str++ = '0' + num;
}
*str = '\0';
}
static void __init print_machine_type(void)
{
static char mach_str[80] __initdata = "Detected machine-type number: ";
char type_str[5];
struct cpuid id;
get_cpu_id(&id);
u16_to_hex(type_str, id.machine);
strcat(mach_str, type_str);
_sclp_print_early(mach_str);
}
static void __init u16_to_decimal(char *str, u16 val)
{
int div = 1;
while (div * 10 <= val)
div *= 10;
while (div) {
*str++ = '0' + val / div;
val %= div;
div /= 10;
}
*str = '\0';
}
static void __init print_missing_facilities(void)
{
static char als_str[80] __initdata = "Missing facilities: ";
unsigned long val;
char val_str[6];
int i, j, first;
first = 1;
for (i = 0; i < ARRAY_SIZE(als); i++) {
val = ~S390_lowcore.stfle_fac_list[i] & als[i];
for (j = 0; j < BITS_PER_LONG; j++) {
if (!(val & (1UL << (BITS_PER_LONG - 1 - j))))
continue;
if (!first)
strcat(als_str, ",");
/*
* Make sure we stay within one line. Consider that
* each facility bit adds up to five characters and
* z/VM adds a four character prefix.
*/
if (strlen(als_str) > 70) {
_sclp_print_early(als_str);
*als_str = '\0';
}
u16_to_decimal(val_str, i * BITS_PER_LONG + j);
strcat(als_str, val_str);
first = 0;
}
}
_sclp_print_early(als_str);
_sclp_print_early("See Principles of Operations for facility bits");
}
static void __init facility_mismatch(void)
{
_sclp_print_early("The Linux kernel requires more recent processor hardware");
print_machine_type();
print_missing_facilities();
disabled_wait(0x8badcccc);
}
void __init verify_facilities(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(S390_lowcore.stfle_fac_list); i++)
S390_lowcore.stfle_fac_list[i] = 0;
asm volatile(
" stfl 0(0)\n"
: "=m" (S390_lowcore.stfl_fac_list));
S390_lowcore.stfle_fac_list[0] = (u64)S390_lowcore.stfl_fac_list << 32;
if (S390_lowcore.stfl_fac_list & 0x01000000) {
register unsigned long reg0 asm("0") = ARRAY_SIZE(als) - 1;
asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */
: "+d" (reg0)
: "a" (&S390_lowcore.stfle_fac_list)
: "memory", "cc");
}
for (i = 0; i < ARRAY_SIZE(als); i++) {
if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i])
facility_mismatch();
}
}
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