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Diffstat (limited to 'kernel/power/tuxonice_incremental.c')
| -rw-r--r-- | kernel/power/tuxonice_incremental.c | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/kernel/power/tuxonice_incremental.c b/kernel/power/tuxonice_incremental.c new file mode 100644 index 000000000..c5a09789e --- /dev/null +++ b/kernel/power/tuxonice_incremental.c @@ -0,0 +1,402 @@ +/* + * kernel/power/tuxonice_incremental.c + * + * Copyright (C) 2015 Nigel Cunningham (nigel at nigelcunningham com au) + * + * This file is released under the GPLv2. + * + * This file contains routines related to storing incremental images - that + * is, retaining an image after an initial cycle and then storing incremental + * changes on subsequent hibernations. + * + * Based in part on on... + * + * Debug helper to dump the current kernel pagetables of the system + * so that we can see what the various memory ranges are set to. + * + * (C) Copyright 2008 Intel Corporation + * + * Author: Arjan van de Ven <arjan@linux.intel.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + +#include <linux/mm.h> +#include <linux/tuxonice.h> +#include <linux/sched.h> +#include <asm/pgtable.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/page.h> +#include "tuxonice_pageflags.h" +#include "tuxonice_builtin.h" +#include "power.h" + +int toi_do_incremental_initcall; + +extern void kdb_init(int level); +extern noinline void kgdb_breakpoint(void); + +#undef pr_debug +#if 0 +#define pr_debug(a, b...) do { printk(a, ##b); } while(0) +#else +#define pr_debug(a, b...) do { } while(0) +#endif + +/* Multipliers for offsets within the PTEs */ +#define PTE_LEVEL_MULT (PAGE_SIZE) +#define PMD_LEVEL_MULT (PTRS_PER_PTE * PTE_LEVEL_MULT) +#define PUD_LEVEL_MULT (PTRS_PER_PMD * PMD_LEVEL_MULT) +#define PGD_LEVEL_MULT (PTRS_PER_PUD * PUD_LEVEL_MULT) + +/* + * This function gets called on a break in a continuous series + * of PTE entries; the next one is different so we need to + * print what we collected so far. + */ +static void note_page(void *addr) +{ + static struct page *lastpage; + struct page *page; + + page = virt_to_page(addr); + + if (page != lastpage) { + unsigned int level; + pte_t *pte = lookup_address((unsigned long) addr, &level); + struct page *pt_page2 = pte_page(*pte); + //debug("Note page %p (=> %p => %p|%ld).\n", addr, pte, pt_page2, page_to_pfn(pt_page2)); + SetPageTOI_Untracked(pt_page2); + lastpage = page; + } +} + +static void walk_pte_level(pmd_t addr) +{ + int i; + pte_t *start; + + start = (pte_t *) pmd_page_vaddr(addr); + for (i = 0; i < PTRS_PER_PTE; i++) { + note_page(start); + start++; + } +} + +#if PTRS_PER_PMD > 1 + +static void walk_pmd_level(pud_t addr) +{ + int i; + pmd_t *start; + + start = (pmd_t *) pud_page_vaddr(addr); + for (i = 0; i < PTRS_PER_PMD; i++) { + if (!pmd_none(*start)) { + if (pmd_large(*start) || !pmd_present(*start)) + note_page(start); + else + walk_pte_level(*start); + } else + note_page(start); + start++; + } +} + +#else +#define walk_pmd_level(a) walk_pte_level(__pmd(pud_val(a))) +#define pud_large(a) pmd_large(__pmd(pud_val(a))) +#define pud_none(a) pmd_none(__pmd(pud_val(a))) +#endif + +#if PTRS_PER_PUD > 1 + +static void walk_pud_level(pgd_t addr) +{ + int i; + pud_t *start; + + start = (pud_t *) pgd_page_vaddr(addr); + + for (i = 0; i < PTRS_PER_PUD; i++) { + if (!pud_none(*start)) { + if (pud_large(*start) || !pud_present(*start)) + note_page(start); + else + walk_pmd_level(*start); + } else + note_page(start); + + start++; + } +} + +#else +#define walk_pud_level(a) walk_pmd_level(__pud(pgd_val(a))) +#define pgd_large(a) pud_large(__pud(pgd_val(a))) +#define pgd_none(a) pud_none(__pud(pgd_val(a))) +#endif + +/* + * Not static in the original at the time of writing, so needs renaming here. + */ +static void toi_ptdump_walk_pgd_level(pgd_t *pgd) +{ +#ifdef CONFIG_X86_64 + pgd_t *start = (pgd_t *) &init_level4_pgt; +#else + pgd_t *start = swapper_pg_dir; +#endif + int i; + if (pgd) { + start = pgd; + } + + for (i = 0; i < PTRS_PER_PGD; i++) { + if (!pgd_none(*start)) { + if (pgd_large(*start) || !pgd_present(*start)) + note_page(start); + else + walk_pud_level(*start); + } else + note_page(start); + + start++; + } + + /* Flush out the last page */ + note_page(start); +} + +#ifdef CONFIG_PARAVIRT +extern struct pv_info pv_info; + +static void toi_set_paravirt_ops_untracked(void) { + int i; + + unsigned long pvpfn = page_to_pfn(virt_to_page(__parainstructions)), + pvpfn_end = page_to_pfn(virt_to_page(__parainstructions_end)); + //debug(KERN_EMERG ".parainstructions goes from pfn %ld to %ld.\n", pvpfn, pvpfn_end); + for (i = pvpfn; i <= pvpfn_end; i++) { + SetPageTOI_Untracked(pfn_to_page(i)); + } +} +#else +#define toi_set_paravirt_ops_untracked() { do { } while(0) } +#endif + +extern void toi_mark_per_cpus_pages_untracked(void); + +void toi_untrack_stack(unsigned long *stack) +{ + int i; + struct page *stack_page = virt_to_page(stack); + + for (i = 0; i < (1 << THREAD_SIZE_ORDER); i++) { + pr_debug("Untrack stack page %p.\n", page_address(stack_page + i)); + SetPageTOI_Untracked(stack_page + i); + } +} +void toi_untrack_process(struct task_struct *p) +{ + SetPageTOI_Untracked(virt_to_page(p)); + pr_debug("Untrack process %d page %p.\n", p->pid, page_address(virt_to_page(p))); + + toi_untrack_stack(p->stack); +} + +void toi_generate_untracked_map(void) +{ + struct task_struct *p, *t; + struct page *page; + pte_t *pte; + int i; + unsigned int level; + static int been_here = 0; + + if (been_here) + return; + + been_here = 1; + + /* Pagetable pages */ + toi_ptdump_walk_pgd_level(NULL); + + /* Printk buffer - not normally needed but can be helpful for debugging. */ + //toi_set_logbuf_untracked(); + + /* Paravirt ops */ + toi_set_paravirt_ops_untracked(); + + /* Task structs and stacks */ + for_each_process_thread(p, t) { + toi_untrack_process(p); + //toi_untrack_stack((unsigned long *) t->thread.sp); + } + + for (i = 0; i < NR_CPUS; i++) { + struct task_struct *idle = idle_task(i); + + if (idle) { + pr_debug("Untrack idle process for CPU %d.\n", i); + toi_untrack_process(idle); + } + + /* IRQ stack */ + pr_debug("Untrack IRQ stack for CPU %d.\n", i); + toi_untrack_stack((unsigned long *)per_cpu(irq_stack_ptr, i)); + } + + /* Per CPU data */ + //pr_debug("Untracking per CPU variable pages.\n"); + toi_mark_per_cpus_pages_untracked(); + + /* Init stack - for bringing up secondary CPUs */ + page = virt_to_page(init_stack); + for (i = 0; i < DIV_ROUND_UP(sizeof(init_stack), PAGE_SIZE); i++) { + SetPageTOI_Untracked(page + i); + } + + pte = lookup_address((unsigned long) &mmu_cr4_features, &level); + SetPageTOI_Untracked(pte_page(*pte)); + SetPageTOI_Untracked(virt_to_page(trampoline_cr4_features)); +} + +/** + * toi_reset_dirtiness_one + */ + +void toi_reset_dirtiness_one(unsigned long pfn, int verbose) +{ + struct page *page = pfn_to_page(pfn); + + /** + * Don't worry about whether the Dirty flag is + * already set. If this is our first call, it + * won't be. + */ + + preempt_disable(); + + ClearPageTOI_Dirty(page); + SetPageTOI_RO(page); + if (verbose) + printk(KERN_EMERG "Making page %ld (%p|%p) read only.\n", pfn, page, page_address(page)); + + set_memory_ro((unsigned long) page_address(page), 1); + + preempt_enable(); +} + +/** + * TuxOnIce's incremental image support works by marking all memory apart from + * the page tables read-only, then in the page-faults that result enabling + * writing if appropriate and flagging the page as dirty. Free pages are also + * marked as dirty and not protected so that if allocated, they will be included + * in the image without further processing. + * + * toi_reset_dirtiness is called when and image exists and incremental images are + * enabled, and each time we resume thereafter. It is not invoked on a fresh boot. + * + * This routine should be called from a single-cpu-running context to avoid races in setting + * page dirty/read only flags. + * + * TODO: Make "it is not invoked on a fresh boot" true when I've finished developing it! + * + * TODO: Consider Xen paravirt guest boot issues. See arch/x86/mm/pageattr.c. + **/ + +int toi_reset_dirtiness(int verbose) +{ + struct zone *zone; + unsigned long loop; + int allocated_map = 0; + + toi_generate_untracked_map(); + + if (!free_map) { + if (!toi_alloc_bitmap(&free_map)) + return -ENOMEM; + allocated_map = 1; + } + + toi_generate_free_page_map(); + + pr_debug(KERN_EMERG "Reset dirtiness.\n"); + for_each_populated_zone(zone) { + // 64 bit only. No need to worry about highmem. + for (loop = 0; loop < zone->spanned_pages; loop++) { + unsigned long pfn = zone->zone_start_pfn + loop; + struct page *page; + int chunk_size; + + if (!pfn_valid(pfn)) { + continue; + } + + chunk_size = toi_size_of_free_region(zone, pfn); + if (chunk_size) { + loop += chunk_size - 1; + continue; + } + + page = pfn_to_page(pfn); + + if (PageNosave(page) || !saveable_page(zone, pfn)) { + continue; + } + + if (PageTOI_Untracked(page)) { + continue; + } + + /** + * Do we need to (re)protect the page? + * If it is already protected (PageTOI_RO), there is + * nothing to do - skip the following. + * If it is marked as dirty (PageTOI_Dirty), it was + * either free and has been allocated or has been + * written to and marked dirty. Reset the dirty flag + * and (re)apply the protection. + */ + if (!PageTOI_RO(page)) { + toi_reset_dirtiness_one(pfn, verbose); + } + } + } + + pr_debug(KERN_EMERG "Done resetting dirtiness.\n"); + + if (allocated_map) { + toi_free_bitmap(&free_map); + } + return 0; +} + +static int toi_reset_dirtiness_initcall(void) +{ + if (toi_do_incremental_initcall) { + pr_info("TuxOnIce: Enabling dirty page tracking.\n"); + toi_reset_dirtiness(0); + } + return 1; +} +extern void toi_generate_untracked_map(void); + +// Leave early_initcall for pages to register untracked sections. +early_initcall(toi_reset_dirtiness_initcall); + +static int __init toi_incremental_initcall_setup(char *str) +{ + int value; + + if (sscanf(str, "=%d", &value) && value) + toi_do_incremental_initcall = value; + + return 1; +} +__setup("toi_incremental_initcall", toi_incremental_initcall_setup); |