arch/arm64/kernel/hibernate.c

Source file repositories/reference/linux-study-clean/arch/arm64/kernel/hibernate.c

File Facts

System
Linux kernel
Corpus path
arch/arm64/kernel/hibernate.c
Extension
.c
Size
11755 bytes
Lines
484
Domain
Architecture Layer
Bucket
arch/arm64
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration 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.

Dependency Surface

Detected Declarations

Annotated Snippet

struct arch_hibernate_hdr_invariants {
	char		uts_version[__NEW_UTS_LEN + 1];
};

/* These values need to be know across a hibernate/restore. */
static struct arch_hibernate_hdr {
	struct arch_hibernate_hdr_invariants invariants;

	/* These are needed to find the relocated kernel if built with kaslr */
	phys_addr_t	ttbr1_el1;
	void		(*reenter_kernel)(void);

	/*
	 * We need to know where the __hyp_stub_vectors are after restore to
	 * re-configure el2.
	 */
	phys_addr_t	__hyp_stub_vectors;

	u64		sleep_cpu_mpidr;
} resume_hdr;

static inline void arch_hdr_invariants(struct arch_hibernate_hdr_invariants *i)
{
	memset(i, 0, sizeof(*i));
	memcpy(i->uts_version, init_utsname()->version, sizeof(i->uts_version));
}

int pfn_is_nosave(unsigned long pfn)
{
	unsigned long nosave_begin_pfn = sym_to_pfn(&__nosave_begin);
	unsigned long nosave_end_pfn = sym_to_pfn(&__nosave_end - 1);

	return ((pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn)) ||
		crash_is_nosave(pfn);
}

void notrace save_processor_state(void)
{
}

void notrace restore_processor_state(void)
{
}

int arch_hibernation_header_save(void *addr, unsigned int max_size)
{
	struct arch_hibernate_hdr *hdr = addr;

	if (max_size < sizeof(*hdr))
		return -EOVERFLOW;

	arch_hdr_invariants(&hdr->invariants);
	hdr->ttbr1_el1		= __pa_symbol(swapper_pg_dir);
	hdr->reenter_kernel	= _cpu_resume;

	/* We can't use __hyp_get_vectors() because kvm may still be loaded */
	if (el2_reset_needed())
		hdr->__hyp_stub_vectors = __pa_symbol(__hyp_stub_vectors);
	else
		hdr->__hyp_stub_vectors = 0;

	/* Save the mpidr of the cpu we called cpu_suspend() on... */
	if (sleep_cpu < 0) {
		pr_err("Failing to hibernate on an unknown CPU.\n");
		return -ENODEV;
	}
	hdr->sleep_cpu_mpidr = cpu_logical_map(sleep_cpu);
	pr_info("Hibernating on CPU %d [mpidr:0x%llx]\n", sleep_cpu,
		hdr->sleep_cpu_mpidr);

	return 0;
}
EXPORT_SYMBOL(arch_hibernation_header_save);

int arch_hibernation_header_restore(void *addr)
{
	int ret;
	struct arch_hibernate_hdr_invariants invariants;
	struct arch_hibernate_hdr *hdr = addr;

	arch_hdr_invariants(&invariants);
	if (memcmp(&hdr->invariants, &invariants, sizeof(invariants))) {
		pr_crit("Hibernate image not generated by this kernel!\n");
		return -EINVAL;
	}

	sleep_cpu = get_logical_index(hdr->sleep_cpu_mpidr);
	pr_info("Hibernated on CPU %d [mpidr:0x%llx]\n", sleep_cpu,
		hdr->sleep_cpu_mpidr);
	if (sleep_cpu < 0) {

Annotation

Implementation Notes