Add TuxOnIce support

1 files changed, 392 insertions, 0 deletions

diff --git a/kernel/power/tuxonice_checksum.c b/kernel/power/tuxonice_checksum.c
new file mode 100644
index 000000000..1c4e10c72
--- /dev/null
+++ b/kernel/power/tuxonice_checksum.c
@@ -0,0 +1,392 @@
+/*
+ * kernel/power/tuxonice_checksum.c
+ *
+ * Copyright (C) 2006-2015 Nigel Cunningham (nigel at nigelcunningham com au)
+ *
+ * This file is released under the GPLv2.
+ *
+ * This file contains data checksum routines for TuxOnIce,
+ * using cryptoapi. They are used to locate any modifications
+ * made to pageset 2 while we're saving it.
+ */
+
+#include <linux/suspend.h>
+#include <linux/highmem.h>
+#include <linux/vmalloc.h>
+#include <linux/crypto.h>
+#include <linux/scatterlist.h>
+
+#include "tuxonice.h"
+#include "tuxonice_modules.h"
+#include "tuxonice_sysfs.h"
+#include "tuxonice_io.h"
+#include "tuxonice_pageflags.h"
+#include "tuxonice_checksum.h"
+#include "tuxonice_pagedir.h"
+#include "tuxonice_alloc.h"
+#include "tuxonice_ui.h"
+
+static struct toi_module_ops toi_checksum_ops;
+
+/* Constant at the mo, but I might allow tuning later */
+static char toi_checksum_name[32] = "md4";
+/* Bytes per checksum */
+#define CHECKSUM_SIZE (16)
+
+#define CHECKSUMS_PER_PAGE ((PAGE_SIZE - sizeof(void *)) / CHECKSUM_SIZE)
+
+struct cpu_context {
+        struct crypto_hash *transform;
+        struct hash_desc desc;
+        struct scatterlist sg[2];
+        char *buf;
+};
+
+static DEFINE_PER_CPU(struct cpu_context, contexts);
+static int pages_allocated;
+static unsigned long page_list;
+
+static int toi_num_resaved;
+
+static unsigned long this_checksum, next_page;
+static int checksum_count;
+
+static inline int checksum_pages_needed(void)
+{
+        return DIV_ROUND_UP(pagedir2.size, CHECKSUMS_PER_PAGE);
+}
+
+/* ---- Local buffer management ---- */
+
+/*
+ * toi_checksum_cleanup
+ *
+ * Frees memory allocated for our labours.
+ */
+static void toi_checksum_cleanup(int ending_cycle)
+{
+        int cpu;
+
+        if (ending_cycle) {
+                for_each_online_cpu(cpu) {
+                        struct cpu_context *this = &per_cpu(contexts, cpu);
+                        if (this->transform) {
+                                crypto_free_hash(this->transform);
+                                this->transform = NULL;
+                                this->desc.tfm = NULL;
+                        }
+
+                        if (this->buf) {
+                                toi_free_page(27, (unsigned long) this->buf);
+                                this->buf = NULL;
+                        }
+                }
+        }
+}
+
+/*
+ * toi_crypto_initialise
+ *
+ * Prepare to do some work by allocating buffers and transforms.
+ * Returns: Int: Zero. Even if we can't set up checksum, we still
+ * seek to hibernate.
+ */
+static int toi_checksum_initialise(int starting_cycle)
+{
+        int cpu;
+
+        if (!(starting_cycle & SYSFS_HIBERNATE) || !toi_checksum_ops.enabled)
+                return 0;
+
+        if (!*toi_checksum_name) {
+                printk(KERN_INFO "TuxOnIce: No checksum algorithm name set.\n");
+                return 1;
+        }
+
+        for_each_online_cpu(cpu) {
+                struct cpu_context *this = &per_cpu(contexts, cpu);
+                struct page *page;
+
+                this->transform = crypto_alloc_hash(toi_checksum_name, 0, 0);
+                if (IS_ERR(this->transform)) {
+                        printk(KERN_INFO "TuxOnIce: Failed to initialise the "
+                                "%s checksum algorithm: %ld.\n",
+                                toi_checksum_name, (long) this->transform);
+                        this->transform = NULL;
+                        return 1;
+                }
+
+                this->desc.tfm = this->transform;
+                this->desc.flags = 0;
+
+                page = toi_alloc_page(27, GFP_KERNEL);
+                if (!page)
+                        return 1;
+                this->buf = page_address(page);
+                sg_init_one(&this->sg[0], this->buf, PAGE_SIZE);
+        }
+        return 0;
+}
+
+/*
+ * toi_checksum_print_debug_stats
+ * @buffer: Pointer to a buffer into which the debug info will be printed.
+ * @size: Size of the buffer.
+ *
+ * Print information to be recorded for debugging purposes into a buffer.
+ * Returns: Number of characters written to the buffer.
+ */
+
+static int toi_checksum_print_debug_stats(char *buffer, int size)
+{
+        int len;
+
+        if (!toi_checksum_ops.enabled)
+                return scnprintf(buffer, size,
+                        "- Checksumming disabled.\n");
+
+        len = scnprintf(buffer, size, "- Checksum method is '%s'.\n",
+                        toi_checksum_name);
+        len += scnprintf(buffer + len, size - len,
+                "  %d pages resaved in atomic copy.\n", toi_num_resaved);
+        return len;
+}
+
+static int toi_checksum_memory_needed(void)
+{
+        return toi_checksum_ops.enabled ?
+                checksum_pages_needed() << PAGE_SHIFT : 0;
+}
+
+static int toi_checksum_storage_needed(void)
+{
+        if (toi_checksum_ops.enabled)
+                return strlen(toi_checksum_name) + sizeof(int) + 1;
+        else
+                return 0;
+}
+
+/*
+ * toi_checksum_save_config_info
+ * @buffer: Pointer to a buffer of size PAGE_SIZE.
+ *
+ * Save informaton needed when reloading the image at resume time.
+ * Returns: Number of bytes used for saving our data.
+ */
+static int toi_checksum_save_config_info(char *buffer)
+{
+        int namelen = strlen(toi_checksum_name) + 1;
+        int total_len;
+
+        *((unsigned int *) buffer) = namelen;
+        strncpy(buffer + sizeof(unsigned int), toi_checksum_name, namelen);
+        total_len = sizeof(unsigned int) + namelen;
+        return total_len;
+}
+
+/* toi_checksum_load_config_info
+ * @buffer: Pointer to the start of the data.
+ * @size: Number of bytes that were saved.
+ *
+ * Description:        Reload information needed for dechecksuming the image at
+ * resume time.
+ */
+static void toi_checksum_load_config_info(char *buffer, int size)
+{
+        int namelen;
+
+        namelen = *((unsigned int *) (buffer));
+        strncpy(toi_checksum_name, buffer + sizeof(unsigned int),
+                        namelen);
+        return;
+}
+
+/*
+ * Free Checksum Memory
+ */
+
+void free_checksum_pages(void)
+{
+        while (pages_allocated) {
+                unsigned long next = *((unsigned long *) page_list);
+                ClearPageNosave(virt_to_page(page_list));
+                toi_free_page(15, (unsigned long) page_list);
+                page_list = next;
+                pages_allocated--;
+        }
+}
+
+/*
+ * Allocate Checksum Memory
+ */
+
+int allocate_checksum_pages(void)
+{
+        int pages_needed = checksum_pages_needed();
+
+        if (!toi_checksum_ops.enabled)
+                return 0;
+
+        while (pages_allocated < pages_needed) {
+                unsigned long *new_page =
+                  (unsigned long *) toi_get_zeroed_page(15, TOI_ATOMIC_GFP);
+                if (!new_page) {
+                        printk(KERN_ERR "Unable to allocate checksum pages.\n");
+                        return -ENOMEM;
+                }
+                SetPageNosave(virt_to_page(new_page));
+                (*new_page) = page_list;
+                page_list = (unsigned long) new_page;
+                pages_allocated++;
+        }
+
+        next_page = (unsigned long) page_list;
+        checksum_count = 0;
+
+        return 0;
+}
+
+char *tuxonice_get_next_checksum(void)
+{
+        if (!toi_checksum_ops.enabled)
+                return NULL;
+
+        if (checksum_count % CHECKSUMS_PER_PAGE)
+                this_checksum += CHECKSUM_SIZE;
+        else {
+                this_checksum = next_page + sizeof(void *);
+                next_page = *((unsigned long *) next_page);
+        }
+
+        checksum_count++;
+        return (char *) this_checksum;
+}
+
+int tuxonice_calc_checksum(struct page *page, char *checksum_locn)
+{
+        char *pa;
+        int result, cpu = smp_processor_id();
+        struct cpu_context *ctx = &per_cpu(contexts, cpu);
+
+        if (!toi_checksum_ops.enabled)
+                return 0;
+
+        pa = kmap(page);
+        memcpy(ctx->buf, pa, PAGE_SIZE);
+        kunmap(page);
+        result = crypto_hash_digest(&ctx->desc, ctx->sg, PAGE_SIZE,
+                                                checksum_locn);
+        if (result)
+                printk(KERN_ERR "TuxOnIce checksumming: crypto_hash_digest "
+                                "returned %d.\n", result);
+        return result;
+}
+/*
+ * Calculate checksums
+ */
+
+void check_checksums(void)
+{
+        int index = 0, cpu = smp_processor_id();
+        char current_checksum[CHECKSUM_SIZE];
+        struct cpu_context *ctx = &per_cpu(contexts, cpu);
+        unsigned long pfn;
+
+        if (!toi_checksum_ops.enabled) {
+                toi_message(TOI_IO, TOI_VERBOSE, 0, "Checksumming disabled.");
+                return;
+        }
+
+        next_page = (unsigned long) page_list;
+
+        toi_num_resaved = 0;
+        this_checksum = 0;
+
+        toi_trace_index++;
+
+        toi_message(TOI_IO, TOI_VERBOSE, 0, "Verifying checksums.");
+        memory_bm_position_reset(pageset2_map);
+        for (pfn = memory_bm_next_pfn(pageset2_map, 0); pfn != BM_END_OF_MAP;
+                        pfn = memory_bm_next_pfn(pageset2_map, 0)) {
+                int ret, resave_needed = false;
+                char *pa;
+                struct page *page = pfn_to_page(pfn);
+
+                if (index < checksum_count) {
+                    if (index % CHECKSUMS_PER_PAGE) {
+                        this_checksum += CHECKSUM_SIZE;
+                    } else {
+                        this_checksum = next_page + sizeof(void *);
+                        next_page = *((unsigned long *) next_page);
+                    }
+
+                    /* Done when IRQs disabled so must be atomic */
+                    pa = kmap_atomic(page);
+                    memcpy(ctx->buf, pa, PAGE_SIZE);
+                    kunmap_atomic(pa);
+                    ret = crypto_hash_digest(&ctx->desc, ctx->sg, PAGE_SIZE,
+                            current_checksum);
+
+                    if (ret) {
+                        printk(KERN_INFO "Digest failed. Returned %d.\n", ret);
+                        return;
+                    }
+
+                    resave_needed = memcmp(current_checksum, (char *) this_checksum,
+                            CHECKSUM_SIZE);
+                } else {
+                    resave_needed = true;
+                }
+
+                if (resave_needed) {
+                        TOI_TRACE_DEBUG(pfn, "_Resaving %d", resave_needed);
+                        SetPageResave(pfn_to_page(pfn));
+                        toi_num_resaved++;
+                        if (test_action_state(TOI_ABORT_ON_RESAVE_NEEDED))
+                                set_abort_result(TOI_RESAVE_NEEDED);
+                }
+
+                index++;
+        }
+        toi_message(TOI_IO, TOI_VERBOSE, 0, "Checksum verification complete.");
+}
+
+static struct toi_sysfs_data sysfs_params[] = {
+        SYSFS_INT("enabled", SYSFS_RW, &toi_checksum_ops.enabled, 0, 1, 0,
+                        NULL),
+        SYSFS_BIT("abort_if_resave_needed", SYSFS_RW, &toi_bkd.toi_action,
+                        TOI_ABORT_ON_RESAVE_NEEDED, 0)
+};
+
+/*
+ * Ops structure.
+ */
+static struct toi_module_ops toi_checksum_ops = {
+        .type                        = MISC_MODULE,
+        .name                        = "checksumming",
+        .directory                = "checksum",
+        .module                        = THIS_MODULE,
+        .initialise                = toi_checksum_initialise,
+        .cleanup                = toi_checksum_cleanup,
+        .print_debug_info        = toi_checksum_print_debug_stats,
+        .save_config_info        = toi_checksum_save_config_info,
+        .load_config_info        = toi_checksum_load_config_info,
+        .memory_needed                = toi_checksum_memory_needed,
+        .storage_needed                = toi_checksum_storage_needed,
+
+        .sysfs_data                = sysfs_params,
+        .num_sysfs_entries        = sizeof(sysfs_params) /
+                sizeof(struct toi_sysfs_data),
+};
+
+/* ---- Registration ---- */
+int toi_checksum_init(void)
+{
+        int result = toi_register_module(&toi_checksum_ops);
+        return result;
+}
+
+void toi_checksum_exit(void)
+{
+        toi_unregister_module(&toi_checksum_ops);
+}