blob: 7a9820797eae24c1523da6415bc23fd43ddb8a36 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/panic_notifier.h>
#include <linux/seq_file.h>
#include <linux/string.h>
#include <linux/utsname.h>
#include <linux/sched.h>
#include <linux/sched/task.h>
#include <linux/kmsg_dump.h>
#include <linux/suspend.h>
#include <linux/random.h>
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <as-layout.h>
#include <arch.h>
#include <init.h>
#include <kern.h>
#include <kern_util.h>
#include <mem_user.h>
#include <os.h>
#include "um_arch.h"
#define DEFAULT_COMMAND_LINE_ROOT "root=98:0"
#define DEFAULT_COMMAND_LINE_CONSOLE "console=tty0"
/* Changed in add_arg and setup_arch, which run before SMP is started */
static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
static void __init add_arg(char *arg)
{
if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
os_warn("add_arg: Too many command line arguments!\n");
exit(1);
}
if (strlen(command_line) > 0)
strcat(command_line, " ");
strcat(command_line, arg);
}
/*
* These fields are initialized at boot time and not changed.
* XXX This structure is used only in the non-SMP case. Maybe this
* should be moved to smp.c.
*/
struct cpuinfo_um boot_cpu_data = {
.loops_per_jiffy = 0,
.ipi_pipe = { -1, -1 },
.cache_alignment = L1_CACHE_BYTES,
.x86_capability = { 0 }
};
EXPORT_SYMBOL(boot_cpu_data);
union thread_union cpu0_irqstack
__section(".data..init_irqstack") =
{ .thread_info = INIT_THREAD_INFO(init_task) };
/* Changed in setup_arch, which is called in early boot */
static char host_info[(__NEW_UTS_LEN + 1) * 5];
static int show_cpuinfo(struct seq_file *m, void *v)
{
int i = 0;
seq_printf(m, "processor\t: %d\n", i);
seq_printf(m, "vendor_id\t: User Mode Linux\n");
seq_printf(m, "model name\t: UML\n");
seq_printf(m, "mode\t\t: skas\n");
seq_printf(m, "host\t\t: %s\n", host_info);
seq_printf(m, "fpu\t\t: %s\n", cpu_has(&boot_cpu_data, X86_FEATURE_FPU) ? "yes" : "no");
seq_printf(m, "flags\t\t:");
for (i = 0; i < 32*NCAPINTS; i++)
if (cpu_has(&boot_cpu_data, i) && (x86_cap_flags[i] != NULL))
seq_printf(m, " %s", x86_cap_flags[i]);
seq_printf(m, "\n");
seq_printf(m, "cache_alignment\t: %d\n", boot_cpu_data.cache_alignment);
seq_printf(m, "bogomips\t: %lu.%02lu\n",
loops_per_jiffy/(500000/HZ),
(loops_per_jiffy/(5000/HZ)) % 100);
return 0;
}
static void *c_start(struct seq_file *m, loff_t *pos)
{
return *pos < nr_cpu_ids ? &boot_cpu_data + *pos : NULL;
}
static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
++*pos;
return c_start(m, pos);
}
static void c_stop(struct seq_file *m, void *v)
{
}
const struct seq_operations cpuinfo_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = show_cpuinfo,
};
/* Set in linux_main */
unsigned long uml_physmem;
EXPORT_SYMBOL(uml_physmem);
unsigned long uml_reserved; /* Also modified in mem_init */
unsigned long start_vm;
unsigned long end_vm;
/* Set in uml_ncpus_setup */
int ncpus = 1;
/* Set in early boot */
static int have_root __initdata;
static int have_console __initdata;
/* Set in uml_mem_setup and modified in linux_main */
long long physmem_size = 64 * 1024 * 1024;
EXPORT_SYMBOL(physmem_size);
static const char *usage_string =
"User Mode Linux v%s\n"
" available at http://user-mode-linux.sourceforge.net/\n\n";
static int __init uml_version_setup(char *line, int *add)
{
/* Explicitly use printf() to show version in stdout */
printf("%s\n", init_utsname()->release);
exit(0);
return 0;
}
__uml_setup("--version", uml_version_setup,
"--version\n"
" Prints the version number of the kernel.\n\n"
);
static int __init uml_root_setup(char *line, int *add)
{
have_root = 1;
return 0;
}
__uml_setup("root=", uml_root_setup,
"root=<file containing the root fs>\n"
" This is actually used by the generic kernel in exactly the same\n"
" way as in any other kernel. If you configure a number of block\n"
" devices and want to boot off something other than ubd0, you \n"
" would use something like:\n"
" root=/dev/ubd5\n\n"
);
static int __init no_skas_debug_setup(char *line, int *add)
{
os_warn("'debug' is not necessary to gdb UML in skas mode - run\n");
os_warn("'gdb linux'\n");
return 0;
}
__uml_setup("debug", no_skas_debug_setup,
"debug\n"
" this flag is not needed to run gdb on UML in skas mode\n\n"
);
static int __init uml_console_setup(char *line, int *add)
{
have_console = 1;
return 0;
}
__uml_setup("console=", uml_console_setup,
"console=<preferred console>\n"
" Specify the preferred console output driver\n\n"
);
static int __init Usage(char *line, int *add)
{
const char **p;
printf(usage_string, init_utsname()->release);
p = &__uml_help_start;
/* Explicitly use printf() to show help in stdout */
while (p < &__uml_help_end) {
printf("%s", *p);
p++;
}
exit(0);
return 0;
}
__uml_setup("--help", Usage,
"--help\n"
" Prints this message.\n\n"
);
static void __init uml_checksetup(char *line, int *add)
{
struct uml_param *p;
p = &__uml_setup_start;
while (p < &__uml_setup_end) {
size_t n;
n = strlen(p->str);
if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
return;
p++;
}
}
static void __init uml_postsetup(void)
{
initcall_t *p;
p = &__uml_postsetup_start;
while (p < &__uml_postsetup_end) {
(*p)();
p++;
}
return;
}
static int panic_exit(struct notifier_block *self, unsigned long unused1,
void *unused2)
{
kmsg_dump(KMSG_DUMP_PANIC);
bust_spinlocks(1);
bust_spinlocks(0);
uml_exitcode = 1;
os_dump_core();
return NOTIFY_DONE;
}
static struct notifier_block panic_exit_notifier = {
.notifier_call = panic_exit,
.priority = INT_MAX - 1, /* run as 2nd notifier, won't return */
};
void uml_finishsetup(void)
{
atomic_notifier_chain_register(&panic_notifier_list,
&panic_exit_notifier);
uml_postsetup();
new_thread_handler();
}
/* Set during early boot */
unsigned long stub_start;
unsigned long task_size;
EXPORT_SYMBOL(task_size);
unsigned long host_task_size;
unsigned long brk_start;
unsigned long end_iomem;
EXPORT_SYMBOL(end_iomem);
#define MIN_VMALLOC (32 * 1024 * 1024)
static void parse_host_cpu_flags(char *line)
{
int i;
for (i = 0; i < 32*NCAPINTS; i++) {
if ((x86_cap_flags[i] != NULL) && strstr(line, x86_cap_flags[i]))
set_cpu_cap(&boot_cpu_data, i);
}
}
static void parse_cache_line(char *line)
{
long res;
char *to_parse = strstr(line, ":");
if (to_parse) {
to_parse++;
while (*to_parse != 0 && isspace(*to_parse)) {
to_parse++;
}
if (kstrtoul(to_parse, 10, &res) == 0 && is_power_of_2(res))
boot_cpu_data.cache_alignment = res;
else
boot_cpu_data.cache_alignment = L1_CACHE_BYTES;
}
}
int __init linux_main(int argc, char **argv)
{
unsigned long avail, diff;
unsigned long virtmem_size, max_physmem;
unsigned long stack;
unsigned int i;
int add;
for (i = 1; i < argc; i++) {
if ((i == 1) && (argv[i][0] == ' '))
continue;
add = 1;
uml_checksetup(argv[i], &add);
if (add)
add_arg(argv[i]);
}
if (have_root == 0)
add_arg(DEFAULT_COMMAND_LINE_ROOT);
if (have_console == 0)
add_arg(DEFAULT_COMMAND_LINE_CONSOLE);
host_task_size = os_get_top_address();
/* reserve a few pages for the stubs (taking care of data alignment) */
/* align the data portion */
BUILD_BUG_ON(!is_power_of_2(STUB_DATA_PAGES));
stub_start = (host_task_size - 1) & ~(STUB_DATA_PAGES * PAGE_SIZE - 1);
/* another page for the code portion */
stub_start -= PAGE_SIZE;
host_task_size = stub_start;
/*
* TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
* out
*/
task_size = host_task_size & PGDIR_MASK;
/* OS sanity checks that need to happen before the kernel runs */
os_early_checks();
get_host_cpu_features(parse_host_cpu_flags, parse_cache_line);
brk_start = (unsigned long) sbrk(0);
/*
* Increase physical memory size for exec-shield users
* so they actually get what they asked for. This should
* add zero for non-exec shield users
*/
diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
if (diff > 1024 * 1024) {
os_info("Adding %ld bytes to physical memory to account for "
"exec-shield gap\n", diff);
physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
}
uml_physmem = (unsigned long) __binary_start & PAGE_MASK;
/* Reserve up to 4M after the current brk */
uml_reserved = ROUND_4M(brk_start) + (1 << 22);
setup_machinename(init_utsname()->machine);
highmem = 0;
iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
/*
* Zones have to begin on a 1 << MAX_PAGE_ORDER page boundary,
* so this makes sure that's true for highmem
*/
max_physmem &= ~((1 << (PAGE_SHIFT + MAX_PAGE_ORDER)) - 1);
if (physmem_size + iomem_size > max_physmem) {
highmem = physmem_size + iomem_size - max_physmem;
physmem_size -= highmem;
}
high_physmem = uml_physmem + physmem_size;
end_iomem = high_physmem + iomem_size;
high_memory = (void *) end_iomem;
start_vm = VMALLOC_START;
virtmem_size = physmem_size;
stack = (unsigned long) argv;
stack &= ~(1024 * 1024 - 1);
avail = stack - start_vm;
if (physmem_size > avail)
virtmem_size = avail;
end_vm = start_vm + virtmem_size;
if (virtmem_size < physmem_size)
os_info("Kernel virtual memory size shrunk to %lu bytes\n",
virtmem_size);
os_flush_stdout();
return start_uml();
}
int __init __weak read_initrd(void)
{
return 0;
}
void __init setup_arch(char **cmdline_p)
{
u8 rng_seed[32];
stack_protections((unsigned long) &init_thread_info);
setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
mem_total_pages(physmem_size, iomem_size, highmem);
uml_dtb_init();
read_initrd();
paging_init();
strscpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
setup_hostinfo(host_info, sizeof host_info);
if (os_getrandom(rng_seed, sizeof(rng_seed), 0) == sizeof(rng_seed)) {
add_bootloader_randomness(rng_seed, sizeof(rng_seed));
memzero_explicit(rng_seed, sizeof(rng_seed));
}
}
void __init arch_cpu_finalize_init(void)
{
arch_check_bugs();
os_check_bugs();
}
void apply_seal_endbr(s32 *start, s32 *end)
{
}
void apply_retpolines(s32 *start, s32 *end)
{
}
void apply_returns(s32 *start, s32 *end)
{
}
void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
s32 *start_cfi, s32 *end_cfi)
{
}
void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
{
}
void *text_poke(void *addr, const void *opcode, size_t len)
{
/*
* In UML, the only reference to this function is in
* apply_relocate_add(), which shouldn't ever actually call this
* because UML doesn't have live patching.
*/
WARN_ON(1);
return memcpy(addr, opcode, len);
}
void text_poke_sync(void)
{
}
void uml_pm_wake(void)
{
pm_system_wakeup();
}
#ifdef CONFIG_PM_SLEEP
static int um_suspend_valid(suspend_state_t state)
{
return state == PM_SUSPEND_MEM;
}
static int um_suspend_prepare(void)
{
um_irqs_suspend();
return 0;
}
static int um_suspend_enter(suspend_state_t state)
{
if (WARN_ON(state != PM_SUSPEND_MEM))
return -EINVAL;
/*
* This is identical to the idle sleep, but we've just
* (during suspend) turned off all interrupt sources
* except for the ones we want, so now we can only wake
* up on something we actually want to wake up on. All
* timing has also been suspended.
*/
um_idle_sleep();
return 0;
}
static void um_suspend_finish(void)
{
um_irqs_resume();
}
const struct platform_suspend_ops um_suspend_ops = {
.valid = um_suspend_valid,
.prepare = um_suspend_prepare,
.enter = um_suspend_enter,
.finish = um_suspend_finish,
};
static int init_pm_wake_signal(void)
{
/*
* In external time-travel mode we can't use signals to wake up
* since that would mess with the scheduling. We'll have to do
* some additional work to support wakeup on virtio devices or
* similar, perhaps implementing a fake RTC controller that can
* trigger wakeup (and request the appropriate scheduling from
* the external scheduler when going to suspend.)
*/
if (time_travel_mode != TT_MODE_EXTERNAL)
register_pm_wake_signal();
suspend_set_ops(&um_suspend_ops);
return 0;
}
late_initcall(init_pm_wake_signal);
#endif