diff options
Diffstat (limited to 'arch/um/kernel/um_arch.c')
-rw-r--r-- | arch/um/kernel/um_arch.c | 413 |
1 files changed, 413 insertions, 0 deletions
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c new file mode 100644 index 000000000..ca5383a8a --- /dev/null +++ b/arch/um/kernel/um_arch.c @@ -0,0 +1,413 @@ +// 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/module.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 <asm/processor.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> + +#define DEFAULT_COMMAND_LINE "root=98:0" + +/* 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 } +}; + +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 index = 0; + + seq_printf(m, "processor\t: %d\n", index); + 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, "bogomips\t: %lu.%02lu\n\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 ? 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 = 0; + +/* Set in uml_mem_setup and modified in linux_main */ +long long physmem_size = 32 * 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 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 0; +} + +static struct notifier_block panic_exit_notifier = { + .notifier_call = panic_exit, + .next = NULL, + .priority = 0 +}; + +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 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) + +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); + + host_task_size = os_get_top_address(); + /* + * 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(); + + 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_ORDER page boundary, + * so this makes sure that's true for highmem + */ + max_physmem &= ~((1 << (PAGE_SHIFT + MAX_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) +{ + stack_protections((unsigned long) &init_thread_info); + setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem); + mem_total_pages(physmem_size, iomem_size, highmem); + read_initrd(); + + paging_init(); + strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); + *cmdline_p = command_line; + setup_hostinfo(host_info, sizeof host_info); +} + +void __init arch_cpu_finalize_init(void) +{ + arch_check_bugs(); + os_check_bugs(); +} + +void apply_retpolines(s32 *start, s32 *end) +{ +} + +void apply_returns(s32 *start, s32 *end) +{ +} + +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 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(); + return 0; +} + +late_initcall(init_pm_wake_signal); +#endif |