484 lines
12 KiB
C
484 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*:
|
|
* Hibernate support specific for ARM64
|
|
*
|
|
* Derived from work on ARM hibernation support by:
|
|
*
|
|
* Ubuntu project, hibernation support for mach-dove
|
|
* Copyright (C) 2010 Nokia Corporation (Hiroshi Doyu)
|
|
* Copyright (C) 2010 Texas Instruments, Inc. (Teerth Reddy et al.)
|
|
* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
|
|
*/
|
|
#define pr_fmt(x) "hibernate: " x
|
|
#include <linux/cpu.h>
|
|
#include <linux/kvm_host.h>
|
|
#include <linux/pm.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/suspend.h>
|
|
#include <linux/utsname.h>
|
|
|
|
#include <asm/barrier.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/cputype.h>
|
|
#include <asm/daifflags.h>
|
|
#include <asm/irqflags.h>
|
|
#include <asm/kexec.h>
|
|
#include <asm/memory.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/mte.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/smp.h>
|
|
#include <asm/smp_plat.h>
|
|
#include <asm/suspend.h>
|
|
#include <asm/sysreg.h>
|
|
#include <asm/trans_pgd.h>
|
|
#include <asm/virt.h>
|
|
|
|
/*
|
|
* Hibernate core relies on this value being 0 on resume, and marks it
|
|
* __nosavedata assuming it will keep the resume kernel's '0' value. This
|
|
* doesn't happen with either KASLR.
|
|
*
|
|
* defined as "__visible int in_suspend __nosavedata" in
|
|
* kernel/power/hibernate.c
|
|
*/
|
|
extern int in_suspend;
|
|
|
|
/* Do we need to reset el2? */
|
|
#define el2_reset_needed() (is_hyp_nvhe())
|
|
|
|
/* hyp-stub vectors, used to restore el2 during resume from hibernate. */
|
|
extern char __hyp_stub_vectors[];
|
|
|
|
/*
|
|
* The logical cpu number we should resume on, initialised to a non-cpu
|
|
* number.
|
|
*/
|
|
static int sleep_cpu = -EINVAL;
|
|
|
|
/*
|
|
* Values that may not change over hibernate/resume. We put the build number
|
|
* and date in here so that we guarantee not to resume with a different
|
|
* kernel.
|
|
*/
|
|
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)
|
|
{
|
|
WARN_ON(num_online_cpus() != 1);
|
|
}
|
|
|
|
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) {
|
|
pr_crit("Hibernated on a CPU not known to this kernel!\n");
|
|
sleep_cpu = -EINVAL;
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = bringup_hibernate_cpu(sleep_cpu);
|
|
if (ret) {
|
|
sleep_cpu = -EINVAL;
|
|
return ret;
|
|
}
|
|
|
|
resume_hdr = *hdr;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(arch_hibernation_header_restore);
|
|
|
|
static void *hibernate_page_alloc(void *arg)
|
|
{
|
|
return (void *)get_safe_page((__force gfp_t)(unsigned long)arg);
|
|
}
|
|
|
|
/*
|
|
* Copies length bytes, starting at src_start into an new page,
|
|
* perform cache maintenance, then maps it at the specified address low
|
|
* address as executable.
|
|
*
|
|
* This is used by hibernate to copy the code it needs to execute when
|
|
* overwriting the kernel text. This function generates a new set of page
|
|
* tables, which it loads into ttbr0.
|
|
*
|
|
* Length is provided as we probably only want 4K of data, even on a 64K
|
|
* page system.
|
|
*/
|
|
static int create_safe_exec_page(void *src_start, size_t length,
|
|
phys_addr_t *phys_dst_addr)
|
|
{
|
|
struct trans_pgd_info trans_info = {
|
|
.trans_alloc_page = hibernate_page_alloc,
|
|
.trans_alloc_arg = (__force void *)GFP_ATOMIC,
|
|
};
|
|
|
|
void *page = (void *)get_safe_page(GFP_ATOMIC);
|
|
phys_addr_t trans_ttbr0;
|
|
unsigned long t0sz;
|
|
int rc;
|
|
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
memcpy(page, src_start, length);
|
|
caches_clean_inval_pou((unsigned long)page, (unsigned long)page + length);
|
|
rc = trans_pgd_idmap_page(&trans_info, &trans_ttbr0, &t0sz, page);
|
|
if (rc)
|
|
return rc;
|
|
|
|
cpu_install_ttbr0(trans_ttbr0, t0sz);
|
|
*phys_dst_addr = virt_to_phys(page);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_ARM64_MTE
|
|
|
|
static DEFINE_XARRAY(mte_pages);
|
|
|
|
static int save_tags(struct page *page, unsigned long pfn)
|
|
{
|
|
void *tag_storage, *ret;
|
|
|
|
tag_storage = mte_allocate_tag_storage();
|
|
if (!tag_storage)
|
|
return -ENOMEM;
|
|
|
|
mte_save_page_tags(page_address(page), tag_storage);
|
|
|
|
ret = xa_store(&mte_pages, pfn, tag_storage, GFP_KERNEL);
|
|
if (WARN(xa_is_err(ret), "Failed to store MTE tags")) {
|
|
mte_free_tag_storage(tag_storage);
|
|
return xa_err(ret);
|
|
} else if (WARN(ret, "swsusp: %s: Duplicate entry", __func__)) {
|
|
mte_free_tag_storage(ret);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void swsusp_mte_free_storage(void)
|
|
{
|
|
XA_STATE(xa_state, &mte_pages, 0);
|
|
void *tags;
|
|
|
|
xa_lock(&mte_pages);
|
|
xas_for_each(&xa_state, tags, ULONG_MAX) {
|
|
mte_free_tag_storage(tags);
|
|
}
|
|
xa_unlock(&mte_pages);
|
|
|
|
xa_destroy(&mte_pages);
|
|
}
|
|
|
|
static int swsusp_mte_save_tags(void)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long pfn, max_zone_pfn;
|
|
int ret = 0;
|
|
int n = 0;
|
|
|
|
if (!system_supports_mte())
|
|
return 0;
|
|
|
|
for_each_populated_zone(zone) {
|
|
max_zone_pfn = zone_end_pfn(zone);
|
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) {
|
|
struct page *page = pfn_to_online_page(pfn);
|
|
|
|
if (!page)
|
|
continue;
|
|
|
|
if (!test_bit(PG_mte_tagged, &page->flags))
|
|
continue;
|
|
|
|
ret = save_tags(page, pfn);
|
|
if (ret) {
|
|
swsusp_mte_free_storage();
|
|
goto out;
|
|
}
|
|
|
|
n++;
|
|
}
|
|
}
|
|
pr_info("Saved %d MTE pages\n", n);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static void swsusp_mte_restore_tags(void)
|
|
{
|
|
XA_STATE(xa_state, &mte_pages, 0);
|
|
int n = 0;
|
|
void *tags;
|
|
|
|
xa_lock(&mte_pages);
|
|
xas_for_each(&xa_state, tags, ULONG_MAX) {
|
|
unsigned long pfn = xa_state.xa_index;
|
|
struct page *page = pfn_to_online_page(pfn);
|
|
|
|
/*
|
|
* It is not required to invoke page_kasan_tag_reset(page)
|
|
* at this point since the tags stored in page->flags are
|
|
* already restored.
|
|
*/
|
|
mte_restore_page_tags(page_address(page), tags);
|
|
|
|
mte_free_tag_storage(tags);
|
|
n++;
|
|
}
|
|
xa_unlock(&mte_pages);
|
|
|
|
pr_info("Restored %d MTE pages\n", n);
|
|
|
|
xa_destroy(&mte_pages);
|
|
}
|
|
|
|
#else /* CONFIG_ARM64_MTE */
|
|
|
|
static int swsusp_mte_save_tags(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void swsusp_mte_restore_tags(void)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_ARM64_MTE */
|
|
|
|
int swsusp_arch_suspend(void)
|
|
{
|
|
int ret = 0;
|
|
unsigned long flags;
|
|
struct sleep_stack_data state;
|
|
|
|
if (cpus_are_stuck_in_kernel()) {
|
|
pr_err("Can't hibernate: no mechanism to offline secondary CPUs.\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
flags = local_daif_save();
|
|
|
|
if (__cpu_suspend_enter(&state)) {
|
|
/* make the crash dump kernel image visible/saveable */
|
|
crash_prepare_suspend();
|
|
|
|
ret = swsusp_mte_save_tags();
|
|
if (ret)
|
|
return ret;
|
|
|
|
sleep_cpu = smp_processor_id();
|
|
ret = swsusp_save();
|
|
} else {
|
|
/* Clean kernel core startup/idle code to PoC*/
|
|
dcache_clean_inval_poc((unsigned long)__mmuoff_data_start,
|
|
(unsigned long)__mmuoff_data_end);
|
|
dcache_clean_inval_poc((unsigned long)__idmap_text_start,
|
|
(unsigned long)__idmap_text_end);
|
|
|
|
/* Clean kvm setup code to PoC? */
|
|
if (el2_reset_needed()) {
|
|
dcache_clean_inval_poc(
|
|
(unsigned long)__hyp_idmap_text_start,
|
|
(unsigned long)__hyp_idmap_text_end);
|
|
dcache_clean_inval_poc((unsigned long)__hyp_text_start,
|
|
(unsigned long)__hyp_text_end);
|
|
}
|
|
|
|
swsusp_mte_restore_tags();
|
|
|
|
/* make the crash dump kernel image protected again */
|
|
crash_post_resume();
|
|
|
|
/*
|
|
* Tell the hibernation core that we've just restored
|
|
* the memory
|
|
*/
|
|
in_suspend = 0;
|
|
|
|
sleep_cpu = -EINVAL;
|
|
__cpu_suspend_exit();
|
|
|
|
/*
|
|
* Just in case the boot kernel did turn the SSBD
|
|
* mitigation off behind our back, let's set the state
|
|
* to what we expect it to be.
|
|
*/
|
|
spectre_v4_enable_mitigation(NULL);
|
|
}
|
|
|
|
local_daif_restore(flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Setup then Resume from the hibernate image using swsusp_arch_suspend_exit().
|
|
*
|
|
* Memory allocated by get_safe_page() will be dealt with by the hibernate code,
|
|
* we don't need to free it here.
|
|
*/
|
|
int swsusp_arch_resume(void)
|
|
{
|
|
int rc;
|
|
void *zero_page;
|
|
size_t exit_size;
|
|
pgd_t *tmp_pg_dir;
|
|
phys_addr_t el2_vectors;
|
|
void __noreturn (*hibernate_exit)(phys_addr_t, phys_addr_t, void *,
|
|
void *, phys_addr_t, phys_addr_t);
|
|
struct trans_pgd_info trans_info = {
|
|
.trans_alloc_page = hibernate_page_alloc,
|
|
.trans_alloc_arg = (void *)GFP_ATOMIC,
|
|
};
|
|
|
|
/*
|
|
* Restoring the memory image will overwrite the ttbr1 page tables.
|
|
* Create a second copy of just the linear map, and use this when
|
|
* restoring.
|
|
*/
|
|
rc = trans_pgd_create_copy(&trans_info, &tmp_pg_dir, PAGE_OFFSET,
|
|
PAGE_END);
|
|
if (rc)
|
|
return rc;
|
|
|
|
/*
|
|
* We need a zero page that is zero before & after resume in order to
|
|
* to break before make on the ttbr1 page tables.
|
|
*/
|
|
zero_page = (void *)get_safe_page(GFP_ATOMIC);
|
|
if (!zero_page) {
|
|
pr_err("Failed to allocate zero page.\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (el2_reset_needed()) {
|
|
rc = trans_pgd_copy_el2_vectors(&trans_info, &el2_vectors);
|
|
if (rc) {
|
|
pr_err("Failed to setup el2 vectors\n");
|
|
return rc;
|
|
}
|
|
}
|
|
|
|
exit_size = __hibernate_exit_text_end - __hibernate_exit_text_start;
|
|
/*
|
|
* Copy swsusp_arch_suspend_exit() to a safe page. This will generate
|
|
* a new set of ttbr0 page tables and load them.
|
|
*/
|
|
rc = create_safe_exec_page(__hibernate_exit_text_start, exit_size,
|
|
(phys_addr_t *)&hibernate_exit);
|
|
if (rc) {
|
|
pr_err("Failed to create safe executable page for hibernate_exit code.\n");
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* KASLR will cause the el2 vectors to be in a different location in
|
|
* the resumed kernel. Load hibernate's temporary copy into el2.
|
|
*
|
|
* We can skip this step if we booted at EL1, or are running with VHE.
|
|
*/
|
|
if (el2_reset_needed())
|
|
__hyp_set_vectors(el2_vectors);
|
|
|
|
hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1,
|
|
resume_hdr.reenter_kernel, restore_pblist,
|
|
resume_hdr.__hyp_stub_vectors, virt_to_phys(zero_page));
|
|
|
|
return 0;
|
|
}
|
|
|
|
int hibernate_resume_nonboot_cpu_disable(void)
|
|
{
|
|
if (sleep_cpu < 0) {
|
|
pr_err("Failing to resume from hibernate on an unknown CPU.\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
return freeze_secondary_cpus(sleep_cpu);
|
|
}
|