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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/s390/boot/als.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/boot/als.c')
-rw-r--r-- | arch/s390/boot/als.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/arch/s390/boot/als.c b/arch/s390/boot/als.c new file mode 100644 index 000000000..47c48fbfb --- /dev/null +++ b/arch/s390/boot/als.c @@ -0,0 +1,114 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 2016 + */ +#include <linux/kernel.h> +#include <asm/processor.h> +#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_ + * 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[] = { FACILITIES_ALS }; + +static void 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 print_machine_type(void) +{ + static char mach_str[80] = "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); + strcat(mach_str, "\n"); + sclp_early_printk(mach_str); +} + +static void 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'; +} + +void print_missing_facilities(void) +{ + static char als_str[80] = "Missing facilities: "; + unsigned long val; + char val_str[6]; + int i, j, first; + + first = 1; + for (i = 0; i < ARRAY_SIZE(als); i++) { + val = ~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) { + strcat(als_str, "\n"); + sclp_early_printk(als_str); + *als_str = '\0'; + } + u16_to_decimal(val_str, i * BITS_PER_LONG + j); + strcat(als_str, val_str); + first = 0; + } + } + strcat(als_str, "\n"); + sclp_early_printk(als_str); +} + +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(); +} + +void verify_facilities(void) +{ + int i; + + __stfle(stfle_fac_list, ARRAY_SIZE(stfle_fac_list)); + for (i = 0; i < ARRAY_SIZE(als); i++) { + if ((stfle_fac_list[i] & als[i]) != als[i]) + facility_mismatch(); + } +} |