| /*: |
| * 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.) |
| * https://lkml.org/lkml/2010/6/18/4 |
| * https://lists.linux-foundation.org/pipermail/linux-pm/2010-June/027422.html |
| * https://patchwork.kernel.org/patch/96442/ |
| * |
| * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> |
| * |
| * License terms: GNU General Public License (GPL) version 2 |
| */ |
| #define pr_fmt(x) "hibernate: " x |
| #include <linux/kvm_host.h> |
| #include <linux/mm.h> |
| #include <linux/notifier.h> |
| #include <linux/pm.h> |
| #include <linux/sched.h> |
| #include <linux/suspend.h> |
| #include <linux/utsname.h> |
| #include <linux/version.h> |
| |
| #include <asm/barrier.h> |
| #include <asm/cacheflush.h> |
| #include <asm/irqflags.h> |
| #include <asm/memory.h> |
| #include <asm/mmu_context.h> |
| #include <asm/pgalloc.h> |
| #include <asm/pgtable.h> |
| #include <asm/pgtable-hwdef.h> |
| #include <asm/sections.h> |
| #include <asm/smp.h> |
| #include <asm/suspend.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; |
| |
| /* Find a symbols alias in the linear map */ |
| #define LMADDR(x) phys_to_virt(virt_to_phys(x)) |
| |
| /* Do we need to reset el2? */ |
| #define el2_reset_needed() (is_hyp_mode_available() && !is_kernel_in_hyp_mode()) |
| |
| /* |
| * Start/end of the hibernate exit code, this must be copied to a 'safe' |
| * location in memory, and executed from there. |
| */ |
| extern char __hibernate_exit_text_start[], __hibernate_exit_text_end[]; |
| |
| /* temporary el2 vectors in the __hibernate_exit_text section. */ |
| extern char hibernate_el2_vectors[]; |
| |
| /* hyp-stub vectors, used to restore el2 during resume from hibernate. */ |
| extern char __hyp_stub_vectors[]; |
| |
| /* |
| * 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; |
| } 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 = virt_to_pfn(&__nosave_begin); |
| unsigned long nosave_end_pfn = virt_to_pfn(&__nosave_end - 1); |
| |
| return (pfn >= nosave_begin_pfn) && (pfn <= nosave_end_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 = virt_to_phys(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 = virt_to_phys(__hyp_stub_vectors); |
| else |
| hdr->__hyp_stub_vectors = 0; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(arch_hibernation_header_save); |
| |
| int arch_hibernation_header_restore(void *addr) |
| { |
| 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; |
| } |
| |
| resume_hdr = *hdr; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(arch_hibernation_header_restore); |
| |
| /* |
| * Copies length bytes, starting at src_start into an new page, |
| * perform cache maintentance, 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, |
| unsigned long dst_addr, |
| phys_addr_t *phys_dst_addr, |
| void *(*allocator)(gfp_t mask), |
| gfp_t mask) |
| { |
| int rc = 0; |
| pgd_t *pgd; |
| pud_t *pud; |
| pmd_t *pmd; |
| pte_t *pte; |
| unsigned long dst = (unsigned long)allocator(mask); |
| |
| if (!dst) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| |
| memcpy((void *)dst, src_start, length); |
| flush_icache_range(dst, dst + length); |
| |
| pgd = pgd_offset_raw(allocator(mask), dst_addr); |
| if (pgd_none(*pgd)) { |
| pud = allocator(mask); |
| if (!pud) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| pgd_populate(&init_mm, pgd, pud); |
| } |
| |
| pud = pud_offset(pgd, dst_addr); |
| if (pud_none(*pud)) { |
| pmd = allocator(mask); |
| if (!pmd) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| pud_populate(&init_mm, pud, pmd); |
| } |
| |
| pmd = pmd_offset(pud, dst_addr); |
| if (pmd_none(*pmd)) { |
| pte = allocator(mask); |
| if (!pte) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| pmd_populate_kernel(&init_mm, pmd, pte); |
| } |
| |
| pte = pte_offset_kernel(pmd, dst_addr); |
| set_pte(pte, __pte(virt_to_phys((void *)dst) | |
| pgprot_val(PAGE_KERNEL_EXEC))); |
| |
| /* Load our new page tables */ |
| asm volatile("msr ttbr0_el1, %0;" |
| "isb;" |
| "tlbi vmalle1is;" |
| "dsb ish;" |
| "isb" : : "r"(virt_to_phys(pgd))); |
| |
| *phys_dst_addr = virt_to_phys((void *)dst); |
| |
| out: |
| return rc; |
| } |
| |
| |
| 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; |
| } |
| |
| local_dbg_save(flags); |
| |
| if (__cpu_suspend_enter(&state)) { |
| ret = swsusp_save(); |
| } else { |
| /* Clean kernel to PoC for secondary core startup */ |
| __flush_dcache_area(LMADDR(KERNEL_START), KERNEL_END - KERNEL_START); |
| |
| /* |
| * Tell the hibernation core that we've just restored |
| * the memory |
| */ |
| in_suspend = 0; |
| |
| __cpu_suspend_exit(); |
| } |
| |
| local_dbg_restore(flags); |
| |
| return ret; |
| } |
| |
| static int copy_pte(pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long start, |
| unsigned long end) |
| { |
| pte_t *src_pte; |
| pte_t *dst_pte; |
| unsigned long addr = start; |
| |
| dst_pte = (pte_t *)get_safe_page(GFP_ATOMIC); |
| if (!dst_pte) |
| return -ENOMEM; |
| pmd_populate_kernel(&init_mm, dst_pmd, dst_pte); |
| dst_pte = pte_offset_kernel(dst_pmd, start); |
| |
| src_pte = pte_offset_kernel(src_pmd, start); |
| do { |
| if (!pte_none(*src_pte)) |
| /* |
| * Resume will overwrite areas that may be marked |
| * read only (code, rodata). Clear the RDONLY bit from |
| * the temporary mappings we use during restore. |
| */ |
| set_pte(dst_pte, __pte(pte_val(*src_pte) & ~PTE_RDONLY)); |
| } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end); |
| |
| return 0; |
| } |
| |
| static int copy_pmd(pud_t *dst_pud, pud_t *src_pud, unsigned long start, |
| unsigned long end) |
| { |
| pmd_t *src_pmd; |
| pmd_t *dst_pmd; |
| unsigned long next; |
| unsigned long addr = start; |
| |
| if (pud_none(*dst_pud)) { |
| dst_pmd = (pmd_t *)get_safe_page(GFP_ATOMIC); |
| if (!dst_pmd) |
| return -ENOMEM; |
| pud_populate(&init_mm, dst_pud, dst_pmd); |
| } |
| dst_pmd = pmd_offset(dst_pud, start); |
| |
| src_pmd = pmd_offset(src_pud, start); |
| do { |
| next = pmd_addr_end(addr, end); |
| if (pmd_none(*src_pmd)) |
| continue; |
| if (pmd_table(*src_pmd)) { |
| if (copy_pte(dst_pmd, src_pmd, addr, next)) |
| return -ENOMEM; |
| } else { |
| set_pmd(dst_pmd, |
| __pmd(pmd_val(*src_pmd) & ~PMD_SECT_RDONLY)); |
| } |
| } while (dst_pmd++, src_pmd++, addr = next, addr != end); |
| |
| return 0; |
| } |
| |
| static int copy_pud(pgd_t *dst_pgd, pgd_t *src_pgd, unsigned long start, |
| unsigned long end) |
| { |
| pud_t *dst_pud; |
| pud_t *src_pud; |
| unsigned long next; |
| unsigned long addr = start; |
| |
| if (pgd_none(*dst_pgd)) { |
| dst_pud = (pud_t *)get_safe_page(GFP_ATOMIC); |
| if (!dst_pud) |
| return -ENOMEM; |
| pgd_populate(&init_mm, dst_pgd, dst_pud); |
| } |
| dst_pud = pud_offset(dst_pgd, start); |
| |
| src_pud = pud_offset(src_pgd, start); |
| do { |
| next = pud_addr_end(addr, end); |
| if (pud_none(*src_pud)) |
| continue; |
| if (pud_table(*(src_pud))) { |
| if (copy_pmd(dst_pud, src_pud, addr, next)) |
| return -ENOMEM; |
| } else { |
| set_pud(dst_pud, |
| __pud(pud_val(*src_pud) & ~PMD_SECT_RDONLY)); |
| } |
| } while (dst_pud++, src_pud++, addr = next, addr != end); |
| |
| return 0; |
| } |
| |
| static int copy_page_tables(pgd_t *dst_pgd, unsigned long start, |
| unsigned long end) |
| { |
| unsigned long next; |
| unsigned long addr = start; |
| pgd_t *src_pgd = pgd_offset_k(start); |
| |
| dst_pgd = pgd_offset_raw(dst_pgd, start); |
| do { |
| next = pgd_addr_end(addr, end); |
| if (pgd_none(*src_pgd)) |
| continue; |
| if (copy_pud(dst_pgd, src_pgd, addr, next)) |
| return -ENOMEM; |
| } while (dst_pgd++, src_pgd++, addr = next, addr != end); |
| |
| return 0; |
| } |
| |
| /* |
| * 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 = 0; |
| void *zero_page; |
| size_t exit_size; |
| pgd_t *tmp_pg_dir; |
| void *lm_restore_pblist; |
| phys_addr_t phys_hibernate_exit; |
| void __noreturn (*hibernate_exit)(phys_addr_t, phys_addr_t, void *, |
| void *, phys_addr_t, phys_addr_t); |
| |
| /* |
| * Locate the exit code in the bottom-but-one page, so that *NULL |
| * still has disastrous affects. |
| */ |
| hibernate_exit = (void *)PAGE_SIZE; |
| 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, |
| (unsigned long)hibernate_exit, |
| &phys_hibernate_exit, |
| (void *)get_safe_page, GFP_ATOMIC); |
| if (rc) { |
| pr_err("Failed to create safe executable page for hibernate_exit code."); |
| goto out; |
| } |
| |
| /* |
| * The hibernate exit text contains a set of el2 vectors, that will |
| * be executed at el2 with the mmu off in order to reload hyp-stub. |
| */ |
| __flush_dcache_area(hibernate_exit, exit_size); |
| |
| /* |
| * Restoring the memory image will overwrite the ttbr1 page tables. |
| * Create a second copy of just the linear map, and use this when |
| * restoring. |
| */ |
| tmp_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC); |
| if (!tmp_pg_dir) { |
| pr_err("Failed to allocate memory for temporary page tables."); |
| rc = -ENOMEM; |
| goto out; |
| } |
| rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, 0); |
| if (rc) |
| goto out; |
| |
| /* |
| * Since we only copied the linear map, we need to find restore_pblist's |
| * linear map address. |
| */ |
| lm_restore_pblist = LMADDR(restore_pblist); |
| |
| /* |
| * 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()) { |
| phys_addr_t el2_vectors = phys_hibernate_exit; /* base */ |
| el2_vectors += hibernate_el2_vectors - |
| __hibernate_exit_text_start; /* offset */ |
| |
| __hyp_set_vectors(el2_vectors); |
| } |
| |
| /* |
| * 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); |
| |
| hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1, |
| resume_hdr.reenter_kernel, lm_restore_pblist, |
| resume_hdr.__hyp_stub_vectors, virt_to_phys(zero_page)); |
| |
| out: |
| return rc; |
| } |
| |
| static int check_boot_cpu_online_pm_callback(struct notifier_block *nb, |
| unsigned long action, void *ptr) |
| { |
| if (action == PM_HIBERNATION_PREPARE && |
| cpumask_first(cpu_online_mask) != 0) { |
| pr_warn("CPU0 is offline.\n"); |
| return notifier_from_errno(-ENODEV); |
| } |
| |
| return NOTIFY_OK; |
| } |
| |
| static int __init check_boot_cpu_online_init(void) |
| { |
| /* |
| * Set this pm_notifier callback with a lower priority than |
| * cpu_hotplug_pm_callback, so that cpu_hotplug_pm_callback will be |
| * called earlier to disable cpu hotplug before the cpu online check. |
| */ |
| pm_notifier(check_boot_cpu_online_pm_callback, -INT_MAX); |
| |
| return 0; |
| } |
| core_initcall(check_boot_cpu_online_init); |