arch/loongarch/kernel/machine_kexec.c
Source file repositories/reference/linux-study-clean/arch/loongarch/kernel/machine_kexec.c
File Facts
- System
- Linux kernel
- Corpus path
arch/loongarch/kernel/machine_kexec.c- Extension
.c- Size
- 7418 bytes
- Lines
- 296
- Domain
- Architecture Layer
- Bucket
- arch/loongarch
- Inferred role
- Architecture Layer: implementation source
- Status
- source implementation candidate
Why This File Exists
CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/compiler.hlinux/cpu.hlinux/kexec.hlinux/crash_dump.hlinux/delay.hlinux/irq.hlinux/libfdt.hlinux/mm.hlinux/of_fdt.hlinux/reboot.hlinux/sched.hlinux/sched/task_stack.hasm/bootinfo.hasm/cacheflush.hasm/page.h
Detected Declarations
function machine_kexec_preparefunction machine_kexec_cleanupfunction kexec_shutdown_secondaryfunction crash_shutdown_secondaryfunction crash_smp_send_stopfunction machine_shutdownfunction machine_crash_shutdownfunction machine_kexecfunction phys_to_virt
Annotated Snippet
if (!strncmp(bootloader, (char __user *)kimage->segment[i].buf, strlen(bootloader))) {
if (!copy_from_user(cmdline_ptr, kimage->segment[i].buf, COMMAND_LINE_SIZE))
kimage->arch.cmdline_ptr = (unsigned long)cmdline_ptr;
break;
}
}
if (!kimage->arch.cmdline_ptr) {
pr_err("Command line not included in the provided image\n");
return -EINVAL;
}
}
/* kexec/kdump need a safe page to save reboot_code_buffer */
kimage->control_code_page = virt_to_page((void *)KEXEC_CONTROL_CODE);
reboot_code_buffer = (unsigned long)page_address(kimage->control_code_page);
memcpy((void *)reboot_code_buffer, relocate_new_kernel, relocate_new_kernel_size);
#ifdef CONFIG_SMP
/* All secondary cpus now may jump to kexec_smp_wait cycle */
relocated_kexec_smp_wait = reboot_code_buffer + (void *)(kexec_smp_wait - relocate_new_kernel);
#endif
return 0;
}
void machine_kexec_cleanup(struct kimage *kimage)
{
}
void kexec_reboot(void)
{
do_kexec_t do_kexec = NULL;
/*
* We know we were online, and there will be no incoming IPIs at
* this point. Mark online again before rebooting so that the crash
* analysis tool will see us correctly.
*/
set_cpu_online(smp_processor_id(), true);
/* Ensure remote CPUs observe that we're online before rebooting. */
smp_mb__after_atomic();
/*
* Make sure we get correct instructions written by the
* machine_kexec_prepare() CPU.
*/
__asm__ __volatile__ ("\tibar 0\n"::);
#ifdef CONFIG_SMP
/* All secondary cpus go to kexec_smp_wait */
if (smp_processor_id() > 0) {
relocated_kexec_smp_wait(NULL);
BUG();
}
#endif
do_kexec = (void *)reboot_code_buffer;
do_kexec(efi_boot, cmdline_ptr, systable_ptr, start_addr, first_ind_entry);
BUG();
}
#ifdef CONFIG_SMP
static void kexec_shutdown_secondary(void *regs)
{
int cpu = smp_processor_id();
if (!cpu_online(cpu))
return;
/* We won't be sent IPIs any more. */
set_cpu_online(cpu, false);
local_irq_disable();
while (!atomic_read(&kexec_ready_to_reboot))
cpu_relax();
kexec_reboot();
}
static void crash_shutdown_secondary(void *passed_regs)
{
int cpu = smp_processor_id();
struct pt_regs *regs = passed_regs;
/*
Annotation
- Immediate include surface: `linux/compiler.h`, `linux/cpu.h`, `linux/kexec.h`, `linux/crash_dump.h`, `linux/delay.h`, `linux/irq.h`, `linux/libfdt.h`, `linux/mm.h`.
- Detected declarations: `function machine_kexec_prepare`, `function machine_kexec_cleanup`, `function kexec_shutdown_secondary`, `function crash_shutdown_secondary`, `function crash_smp_send_stop`, `function machine_shutdown`, `function machine_crash_shutdown`, `function machine_kexec`, `function phys_to_virt`.
- Atlas domain: Architecture Layer / arch/loongarch.
- Implementation status: source implementation candidate.
- This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.