s390: warn about clearing als implied facilities

Add a warning about removing required architecture level set facilities
via "facilities=" command line option.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Vasily Gorbik 2019-02-27 17:36:35 +01:00 committed by Martin Schwidefsky
parent b5e804598d
commit 6d85dac2ab
3 changed files with 20 additions and 2 deletions

View file

@ -7,6 +7,7 @@
#include <asm/facility.h>
#include <asm/lowcore.h>
#include <asm/sclp.h>
#include "boot.h"
/*
* The code within this file will be called very early. It may _not_
@ -58,7 +59,7 @@ static void u16_to_decimal(char *str, u16 val)
*str = '\0';
}
static void print_missing_facilities(void)
void print_missing_facilities(void)
{
static char als_str[80] = "Missing facilities: ";
unsigned long val;
@ -90,7 +91,6 @@ static void print_missing_facilities(void)
}
strcat(als_str, "\n");
sclp_early_printk(als_str);
sclp_early_printk("See Principles of Operations for facility bits\n");
}
static void facility_mismatch(void)
@ -98,6 +98,7 @@ static void facility_mismatch(void)
sclp_early_printk("The Linux kernel requires more recent processor hardware\n");
print_machine_type();
print_missing_facilities();
sclp_early_printk("See Principles of Operations for facility bits\n");
disabled_wait(0x8badcccc);
}

View file

@ -8,5 +8,6 @@ void store_ipl_parmblock(void);
void setup_boot_command_line(void);
void parse_boot_command_line(void);
void setup_memory_end(void);
void print_missing_facilities(void);
#endif /* BOOT_BOOT_H */

View file

@ -1,4 +1,5 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/ctype.h>
#include <asm/ebcdic.h>
@ -152,6 +153,20 @@ static void modify_facility(unsigned long nr, bool clear)
__set_facility(nr, S390_lowcore.stfle_fac_list);
}
static void check_cleared_facilities(void)
{
unsigned long als[] = { FACILITIES_ALS };
int i;
for (i = 0; i < ARRAY_SIZE(als); i++) {
if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i]) {
sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
print_missing_facilities();
break;
}
}
}
static void modify_fac_list(char *str)
{
unsigned long val, endval;
@ -185,6 +200,7 @@ static void modify_fac_list(char *str)
break;
str++;
}
check_cleared_facilities();
}
static char command_line_buf[COMMAND_LINE_SIZE] __section(.data);