arch/x86/kernel/acpi/madt_playdead.S

File Facts

System

Linux kernel

Corpus path

arch/x86/kernel/acpi/madt_playdead.S

Extension

.S

Size

691 bytes

Lines

30

Domain

Architecture Layer

Bucket

arch/x86

Inferred role

Architecture Layer: arch/x86

Status

atlas-only

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.

Dependency Surface

• linux/linkage.h
• asm/nospec-branch.h
• asm/page_types.h
• asm/processor-flags.h

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

#include <linux/linkage.h>
#include <asm/nospec-branch.h>
#include <asm/page_types.h>
#include <asm/processor-flags.h>

	.text
	.align PAGE_SIZE

/*
 * asm_acpi_mp_play_dead() - Hand over control of the CPU to the BIOS
 *
 * rdi: Address of the ACPI MADT MPWK ResetVector
 * rsi: PGD of the identity mapping
 */
SYM_FUNC_START(asm_acpi_mp_play_dead)
	ANNOTATE_NOENDBR
	/* Turn off global entries. Following CR3 write will flush them. */
	movq	%cr4, %rdx
	andq	$~(X86_CR4_PGE), %rdx
	movq	%rdx, %cr4

	/* Switch to identity mapping */
	movq	%rsi, %cr3

	/* Jump to reset vector */
	ANNOTATE_RETPOLINE_SAFE
	jmp	*%rdi
SYM_FUNC_END(asm_acpi_mp_play_dead)

Annotation

• Immediate include surface: `linux/linkage.h`, `asm/nospec-branch.h`, `asm/page_types.h`, `asm/processor-flags.h`.
• Atlas domain: Architecture Layer / arch/x86.
• Implementation status: atlas-only.

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.