diff options
Diffstat (limited to 'arch/arm64/kernel/hibernate.c')
| -rw-r--r-- | arch/arm64/kernel/hibernate.c | 200 |
1 files changed, 131 insertions, 69 deletions
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c index 21ab5df9fa76..d55a7b09959b 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -15,9 +15,9 @@ * License terms: GNU General Public License (GPL) version 2 */ #define pr_fmt(x) "hibernate: " x +#include <linux/cpu.h> #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> @@ -26,6 +26,7 @@ #include <asm/barrier.h> #include <asm/cacheflush.h> +#include <asm/cputype.h> #include <asm/irqflags.h> #include <asm/memory.h> #include <asm/mmu_context.h> @@ -34,7 +35,9 @@ #include <asm/pgtable-hwdef.h> #include <asm/sections.h> #include <asm/smp.h> +#include <asm/smp_plat.h> #include <asm/suspend.h> +#include <asm/sysreg.h> #include <asm/virt.h> /* @@ -53,12 +56,6 @@ extern int in_suspend; /* 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[]; @@ -66,6 +63,12 @@ extern char hibernate_el2_vectors[]; 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. @@ -87,6 +90,8 @@ static struct arch_hibernate_hdr { * 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) @@ -129,12 +134,22 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size) 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 unkown 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; @@ -144,6 +159,24 @@ int arch_hibernation_header_restore(void *addr) 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; + } + if (!cpu_online(sleep_cpu)) { + pr_info("Hibernated on a CPU that is offline! Bringing CPU up.\n"); + ret = cpu_up(sleep_cpu); + if (ret) { + pr_err("Failed to bring hibernate-CPU up!\n"); + sleep_cpu = -EINVAL; + return ret; + } + } + resume_hdr = *hdr; return 0; @@ -217,12 +250,22 @@ static int create_safe_exec_page(void *src_start, size_t length, 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))); + /* + * Load our new page tables. A strict BBM approach requires that we + * ensure that TLBs are free of any entries that may overlap with the + * global mappings we are about to install. + * + * For a real hibernate/resume cycle TTBR0 currently points to a zero + * page, but TLBs may contain stale ASID-tagged entries (e.g. for EFI + * runtime services), while for a userspace-driven test_resume cycle it + * points to userspace page tables (and we must point it at a zero page + * ourselves). Elsewhere we only (un)install the idmap with preemption + * disabled, so T0SZ should be as required regardless. + */ + cpu_set_reserved_ttbr0(); + local_flush_tlb_all(); + write_sysreg(virt_to_phys(pgd), ttbr0_el1); + isb(); *phys_dst_addr = virt_to_phys((void *)dst); @@ -230,6 +273,7 @@ out: return rc; } +#define dcache_clean_range(start, end) __flush_dcache_area(start, (end - start)) int swsusp_arch_suspend(void) { @@ -245,10 +289,16 @@ int swsusp_arch_suspend(void) local_dbg_save(flags); if (__cpu_suspend_enter(&state)) { + sleep_cpu = smp_processor_id(); ret = swsusp_save(); } else { - /* Clean kernel to PoC for secondary core startup */ - __flush_dcache_area(LMADDR(KERNEL_START), KERNEL_END - KERNEL_START); + /* Clean kernel core startup/idle code to PoC*/ + dcache_clean_range(__mmuoff_data_start, __mmuoff_data_end); + dcache_clean_range(__idmap_text_start, __idmap_text_end); + + /* Clean kvm setup code to PoC? */ + if (el2_reset_needed()) + dcache_clean_range(__hyp_idmap_text_start, __hyp_idmap_text_end); /* * Tell the hibernation core that we've just restored @@ -256,6 +306,7 @@ int swsusp_arch_suspend(void) */ in_suspend = 0; + sleep_cpu = -EINVAL; __cpu_suspend_exit(); } @@ -264,6 +315,33 @@ int swsusp_arch_suspend(void) return ret; } +static void _copy_pte(pte_t *dst_pte, pte_t *src_pte, unsigned long addr) +{ + pte_t pte = *src_pte; + + if (pte_valid(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_clear_rdonly(pte)); + } else if (debug_pagealloc_enabled() && !pte_none(pte)) { + /* + * debug_pagealloc will removed the PTE_VALID bit if + * the page isn't in use by the resume kernel. It may have + * been in use by the original kernel, in which case we need + * to put it back in our copy to do the restore. + * + * Before marking this entry valid, check the pfn should + * be mapped. + */ + BUG_ON(!pfn_valid(pte_pfn(pte))); + + set_pte(dst_pte, pte_mkpresent(pte_clear_rdonly(pte))); + } +} + static int copy_pte(pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long start, unsigned long end) { @@ -279,13 +357,7 @@ static int copy_pte(pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long 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)); + _copy_pte(dst_pte, src_pte, addr); } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end); return 0; @@ -394,6 +466,38 @@ int swsusp_arch_resume(void) void *, phys_addr_t, phys_addr_t); /* + * 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); + + /* + * 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."); + rc = -ENOMEM; + goto out; + } + + /* * Locate the exit code in the bottom-but-one page, so that *NULL * still has disastrous affects. */ @@ -419,27 +523,6 @@ int swsusp_arch_resume(void) __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. * @@ -453,12 +536,6 @@ int swsusp_arch_resume(void) __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)); @@ -467,27 +544,12 @@ out: return rc; } -static int check_boot_cpu_online_pm_callback(struct notifier_block *nb, - unsigned long action, void *ptr) +int hibernate_resume_nonboot_cpu_disable(void) { - if (action == PM_HIBERNATION_PREPARE && - cpumask_first(cpu_online_mask) != 0) { - pr_warn("CPU0 is offline.\n"); - return notifier_from_errno(-ENODEV); + if (sleep_cpu < 0) { + pr_err("Failing to resume from hibernate on an unkown CPU.\n"); + return -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; + return freeze_secondary_cpus(sleep_cpu); } -core_initcall(check_boot_cpu_online_init); |