swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 7d2a07b769330c34b4deabeed939325c77a7ec2f authored by Linus Torvalds on 29 August 2021, 22:04:50 UTC
Linux 5.14
Linux 5.14
Tip revision: 7d2a07b
early.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2007, 2009
* Author(s): Hongjie Yang <hongjie@us.ibm.com>,
* Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#define KMSG_COMPONENT "setup"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/lockdep.h>
#include <linux/extable.h>
#include <linux/pfn.h>
#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <asm/diag.h>
#include <asm/ebcdic.h>
#include <asm/ipl.h>
#include <asm/lowcore.h>
#include <asm/processor.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sysinfo.h>
#include <asm/cpcmd.h>
#include <asm/sclp.h>
#include <asm/facility.h>
#include <asm/boot_data.h>
#include <asm/switch_to.h>
#include "entry.h"
int __bootdata(is_full_image);
static void __init reset_tod_clock(void)
{
union tod_clock clk;
if (store_tod_clock_ext_cc(&clk) == 0)
return;
/* TOD clock not running. Set the clock to Unix Epoch. */
if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
disabled_wait();
memset(&tod_clock_base, 0, sizeof(tod_clock_base));
tod_clock_base.tod = TOD_UNIX_EPOCH;
S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
}
/*
* Initialize storage key for kernel pages
*/
static noinline __init void init_kernel_storage_key(void)
{
#if PAGE_DEFAULT_KEY
unsigned long end_pfn, init_pfn;
end_pfn = PFN_UP(__pa(_end));
for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
page_set_storage_key(init_pfn << PAGE_SHIFT,
PAGE_DEFAULT_KEY, 0);
#endif
}
static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
static noinline __init void detect_machine_type(void)
{
struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
/* Check current-configuration-level */
if (stsi(NULL, 0, 0, 0) <= 2) {
S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
return;
}
/* Get virtual-machine cpu information. */
if (stsi(vmms, 3, 2, 2) || !vmms->count)
return;
/* Detect known hypervisors */
if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
}
/* Remove leading, trailing and double whitespace. */
static inline void strim_all(char *str)
{
char *s;
s = strim(str);
if (s != str)
memmove(str, s, strlen(s));
while (*str) {
if (!isspace(*str++))
continue;
if (isspace(*str)) {
s = skip_spaces(str);
memmove(str, s, strlen(s) + 1);
}
}
}
static noinline __init void setup_arch_string(void)
{
struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
char mstr[80], hvstr[17];
if (stsi(mach, 1, 1, 1))
return;
EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
EBCASC(mach->type, sizeof(mach->type));
EBCASC(mach->model, sizeof(mach->model));
EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
mach->manufacturer, mach->type,
mach->model, mach->model_capacity);
strim_all(mstr);
if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
strim_all(hvstr);
} else {
sprintf(hvstr, "%s",
MACHINE_IS_LPAR ? "LPAR" :
MACHINE_IS_VM ? "z/VM" :
MACHINE_IS_KVM ? "KVM" : "unknown");
}
dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
}
static __init void setup_topology(void)
{
int max_mnest;
if (!test_facility(11))
return;
S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
for (max_mnest = 6; max_mnest > 1; max_mnest--) {
if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
break;
}
topology_max_mnest = max_mnest;
}
static void early_pgm_check_handler(void)
{
const struct exception_table_entry *fixup;
unsigned long cr0, cr0_new;
unsigned long addr;
addr = S390_lowcore.program_old_psw.addr;
fixup = s390_search_extables(addr);
if (!fixup)
disabled_wait();
/* Disable low address protection before storing into lowcore. */
__ctl_store(cr0, 0, 0);
cr0_new = cr0 & ~(1UL << 28);
__ctl_load(cr0_new, 0, 0);
S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
__ctl_load(cr0, 0, 0);
}
static noinline __init void setup_lowcore_early(void)
{
psw_t psw;
psw.addr = (unsigned long)s390_base_pgm_handler;
psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
if (IS_ENABLED(CONFIG_KASAN))
psw.mask |= PSW_MASK_DAT;
S390_lowcore.program_new_psw = psw;
s390_base_pgm_handler_fn = early_pgm_check_handler;
S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
}
static noinline __init void setup_facility_list(void)
{
memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
__clear_facility(82, alt_stfle_fac_list);
}
static __init void detect_diag9c(void)
{
unsigned int cpu_address;
int rc;
cpu_address = stap();
diag_stat_inc(DIAG_STAT_X09C);
asm volatile(
" diag %2,0,0x9c\n"
"0: la %0,0\n"
"1:\n"
EX_TABLE(0b,1b)
: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
if (!rc)
S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
}
static __init void detect_machine_facilities(void)
{
if (test_facility(8)) {
S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
__ctl_set_bit(0, 23);
}
if (test_facility(78))
S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
if (test_facility(3))
S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
if (test_facility(50) && test_facility(73)) {
S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
__ctl_set_bit(0, 55);
}
if (test_facility(51))
S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
if (test_facility(129)) {
S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
__ctl_set_bit(0, 17);
}
if (test_facility(130) && !noexec_disabled) {
S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
__ctl_set_bit(0, 20);
}
if (test_facility(133))
S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
if (test_facility(139) && (tod_clock_base.tod >> 63)) {
/* Enabled signed clock comparator comparisons */
S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
clock_comparator_max = -1ULL >> 1;
__ctl_set_bit(0, 53);
}
}
static inline void save_vector_registers(void)
{
#ifdef CONFIG_CRASH_DUMP
if (test_facility(129))
save_vx_regs(boot_cpu_vector_save_area);
#endif
}
static inline void setup_control_registers(void)
{
unsigned long reg;
__ctl_store(reg, 0, 0);
reg |= CR0_LOW_ADDRESS_PROTECTION;
reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
reg |= CR0_EXTERNAL_CALL_SUBMASK;
__ctl_load(reg, 0, 0);
}
static inline void setup_access_registers(void)
{
unsigned int acrs[NUM_ACRS] = { 0 };
restore_access_regs(acrs);
}
static int __init disable_vector_extension(char *str)
{
S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
__ctl_clear_bit(0, 17);
return 0;
}
early_param("novx", disable_vector_extension);
char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
static void __init setup_boot_command_line(void)
{
/* copy arch command line */
strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
}
static void __init check_image_bootable(void)
{
if (is_full_image)
return;
sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
disabled_wait();
}
void __init startup_init(void)
{
reset_tod_clock();
check_image_bootable();
time_early_init();
init_kernel_storage_key();
lockdep_off();
setup_lowcore_early();
setup_facility_list();
detect_machine_type();
setup_arch_string();
setup_boot_command_line();
detect_diag9c();
detect_machine_facilities();
save_vector_registers();
setup_topology();
sclp_early_detect();
setup_control_registers();
setup_access_registers();
lockdep_on();
}