diff options
Diffstat (limited to 'kernel/power/tuxonice_prune.c')
| -rw-r--r-- | kernel/power/tuxonice_prune.c | 406 |
1 files changed, 0 insertions, 406 deletions
diff --git a/kernel/power/tuxonice_prune.c b/kernel/power/tuxonice_prune.c deleted file mode 100644 index 710e48dee..000000000 --- a/kernel/power/tuxonice_prune.c +++ /dev/null @@ -1,406 +0,0 @@ -/* - * kernel/power/tuxonice_prune.c - * - * Copyright (C) 2012 Nigel Cunningham (nigel at nigelcunningham com au) - * - * This file is released under the GPLv2. - * - * This file implements a TuxOnIce module that seeks to prune the - * amount of data written to disk. It builds a table of hashes - * of the uncompressed data, and writes the pfn of the previous page - * with the same contents instead of repeating the data when a match - * is found. - */ - -#include <linux/suspend.h> -#include <linux/highmem.h> -#include <linux/vmalloc.h> -#include <linux/crypto.h> -#include <linux/scatterlist.h> -#include <crypto/hash.h> - -#include "tuxonice_builtin.h" -#include "tuxonice.h" -#include "tuxonice_modules.h" -#include "tuxonice_sysfs.h" -#include "tuxonice_io.h" -#include "tuxonice_ui.h" -#include "tuxonice_alloc.h" - -/* - * We never write a page bigger than PAGE_SIZE, so use a large number - * to indicate that data is a PFN. - */ -#define PRUNE_DATA_IS_PFN (PAGE_SIZE + 100) - -static unsigned long toi_pruned_pages; - -static struct toi_module_ops toi_prune_ops; -static struct toi_module_ops *next_driver; - -static char toi_prune_hash_algo_name[32] = "sha1"; - -static DEFINE_MUTEX(stats_lock); - -struct cpu_context { - struct shash_desc desc; - char *digest; -}; - -#define OUT_BUF_SIZE (2 * PAGE_SIZE) - -static DEFINE_PER_CPU(struct cpu_context, contexts); - -/* - * toi_crypto_prepare - * - * Prepare to do some work by allocating buffers and transforms. - */ -static int toi_prune_crypto_prepare(void) -{ - int cpu, ret, digestsize; - - if (!*toi_prune_hash_algo_name) { - printk(KERN_INFO "TuxOnIce: Pruning enabled but no " - "hash algorithm set.\n"); - return 1; - } - - for_each_online_cpu(cpu) { - struct cpu_context *this = &per_cpu(contexts, cpu); - this->desc.tfm = crypto_alloc_shash(toi_prune_hash_algo_name, 0, 0); - if (IS_ERR(this->desc.tfm)) { - printk(KERN_INFO "TuxOnIce: Failed to allocate the " - "%s prune hash algorithm.\n", - toi_prune_hash_algo_name); - this->desc.tfm = NULL; - return 1; - } - - if (!digestsize) - digestsize = crypto_shash_digestsize(this->desc.tfm); - - this->digest = kmalloc(digestsize, GFP_KERNEL); - if (!this->digest) { - printk(KERN_INFO "TuxOnIce: Failed to allocate space " - "for digest output.\n"); - crypto_free_shash(this->desc.tfm); - this->desc.tfm = NULL; - } - - this->desc.flags = 0; - - ret = crypto_shash_init(&this->desc); - if (ret < 0) { - printk(KERN_INFO "TuxOnIce: Failed to initialise the " - "%s prune hash algorithm.\n", - toi_prune_hash_algo_name); - kfree(this->digest); - this->digest = NULL; - crypto_free_shash(this->desc.tfm); - this->desc.tfm = NULL; - return 1; - } - } - - return 0; -} - -static int toi_prune_rw_cleanup(int writing) -{ - int cpu; - - for_each_online_cpu(cpu) { - struct cpu_context *this = &per_cpu(contexts, cpu); - if (this->desc.tfm) { - crypto_free_shash(this->desc.tfm); - this->desc.tfm = NULL; - } - - if (this->digest) { - kfree(this->digest); - this->digest = NULL; - } - } - - return 0; -} - -/* - * toi_prune_init - */ - -static int toi_prune_init(int toi_or_resume) -{ - if (!toi_or_resume) - return 0; - - toi_pruned_pages = 0; - - next_driver = toi_get_next_filter(&toi_prune_ops); - - return next_driver ? 0 : -ECHILD; -} - -/* - * toi_prune_rw_init() - */ - -static int toi_prune_rw_init(int rw, int stream_number) -{ - if (toi_prune_crypto_prepare()) { - printk(KERN_ERR "Failed to initialise prune " - "algorithm.\n"); - if (rw == READ) { - printk(KERN_INFO "Unable to read the image.\n"); - return -ENODEV; - } else { - printk(KERN_INFO "Continuing without " - "pruning the image.\n"); - toi_prune_ops.enabled = 0; - } - } - - return 0; -} - -/* - * toi_prune_write_page() - * - * Compress a page of data, buffering output and passing on filled - * pages to the next module in the pipeline. - * - * Buffer_page: Pointer to a buffer of size PAGE_SIZE, containing - * data to be checked. - * - * Returns: 0 on success. Otherwise the error is that returned by later - * modules, -ECHILD if we have a broken pipeline or -EIO if - * zlib errs. - */ -static int toi_prune_write_page(unsigned long index, int buf_type, - void *buffer_page, unsigned int buf_size) -{ - int ret = 0, cpu = smp_processor_id(), write_data = 1; - struct cpu_context *ctx = &per_cpu(contexts, cpu); - u8* output_buffer = buffer_page; - int output_len = buf_size; - int out_buf_type = buf_type; - void *buffer_start; - u32 buf[4]; - - if (ctx->desc.tfm) { - - buffer_start = TOI_MAP(buf_type, buffer_page); - ctx->len = OUT_BUF_SIZE; - - ret = crypto_shash_digest(&ctx->desc, buffer_start, buf_size, &ctx->digest); - if (ret) { - printk(KERN_INFO "TuxOnIce: Failed to calculate digest (%d).\n", ret); - } else { - mutex_lock(&stats_lock); - - toi_pruned_pages++; - - mutex_unlock(&stats_lock); - - } - - TOI_UNMAP(buf_type, buffer_page); - } - - if (write_data) - ret = next_driver->write_page(index, out_buf_type, - output_buffer, output_len); - else - ret = next_driver->write_page(index, out_buf_type, - output_buffer, output_len); - - return ret; -} - -/* - * toi_prune_read_page() - * @buffer_page: struct page *. Pointer to a buffer of size PAGE_SIZE. - * - * Retrieve data from later modules or from a previously loaded page and - * fill the input buffer. - * Zero if successful. Error condition from me or from downstream on failure. - */ -static int toi_prune_read_page(unsigned long *index, int buf_type, - void *buffer_page, unsigned int *buf_size) -{ - int ret, cpu = smp_processor_id(); - unsigned int len; - char *buffer_start; - struct cpu_context *ctx = &per_cpu(contexts, cpu); - - if (!ctx->desc.tfm) - return next_driver->read_page(index, TOI_PAGE, buffer_page, - buf_size); - - /* - * All our reads must be synchronous - we can't handle - * data that hasn't been read yet. - */ - - ret = next_driver->read_page(index, buf_type, buffer_page, &len); - - if (len == PRUNE_DATA_IS_PFN) { - buffer_start = kmap(buffer_page); - } - - return ret; -} - -/* - * toi_prune_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_prune_print_debug_stats(char *buffer, int size) -{ - int len; - - /* Output the number of pages pruned. */ - if (*toi_prune_hash_algo_name) - len = scnprintf(buffer, size, "- Compressor is '%s'.\n", - toi_prune_hash_algo_name); - else - len = scnprintf(buffer, size, "- Compressor is not set.\n"); - - if (toi_pruned_pages) - len += scnprintf(buffer+len, size - len, " Pruned " - "%lu pages).\n", - toi_pruned_pages); - return len; -} - -/* - * toi_prune_memory_needed - * - * Tell the caller how much memory we need to operate during hibernate/resume. - * Returns: Unsigned long. Maximum number of bytes of memory required for - * operation. - */ -static int toi_prune_memory_needed(void) -{ - return 2 * PAGE_SIZE; -} - -static int toi_prune_storage_needed(void) -{ - return 2 * sizeof(unsigned long) + 2 * sizeof(int) + - strlen(toi_prune_hash_algo_name) + 1; -} - -/* - * toi_prune_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_prune_save_config_info(char *buffer) -{ - int len = strlen(toi_prune_hash_algo_name) + 1, offset = 0; - - *((unsigned long *) buffer) = toi_pruned_pages; - offset += sizeof(unsigned long); - *((int *) (buffer + offset)) = len; - offset += sizeof(int); - strncpy(buffer + offset, toi_prune_hash_algo_name, len); - return offset + len; -} - -/* toi_prune_load_config_info - * @buffer: Pointer to the start of the data. - * @size: Number of bytes that were saved. - * - * Description: Reload information needed for passing back to the - * resumed kernel. - */ -static void toi_prune_load_config_info(char *buffer, int size) -{ - int len, offset = 0; - - toi_pruned_pages = *((unsigned long *) buffer); - offset += sizeof(unsigned long); - len = *((int *) (buffer + offset)); - offset += sizeof(int); - strncpy(toi_prune_hash_algo_name, buffer + offset, len); -} - -static void toi_prune_pre_atomic_restore(struct toi_boot_kernel_data *bkd) -{ - bkd->pruned_pages = toi_pruned_pages; -} - -static void toi_prune_post_atomic_restore(struct toi_boot_kernel_data *bkd) -{ - toi_pruned_pages = bkd->pruned_pages; -} - -/* - * toi_expected_ratio - * - * Description: Returns the expected ratio between data passed into this module - * and the amount of data output when writing. - * Returns: 100 - we have no idea how many pages will be pruned. - */ - -static int toi_prune_expected_ratio(void) -{ - return 100; -} - -/* - * data for our sysfs entries. - */ -static struct toi_sysfs_data sysfs_params[] = { - SYSFS_INT("enabled", SYSFS_RW, &toi_prune_ops.enabled, 0, 1, 0, - NULL), - SYSFS_STRING("algorithm", SYSFS_RW, toi_prune_hash_algo_name, 31, 0, NULL), -}; - -/* - * Ops structure. - */ -static struct toi_module_ops toi_prune_ops = { - .type = FILTER_MODULE, - .name = "prune", - .directory = "prune", - .module = THIS_MODULE, - .initialise = toi_prune_init, - .memory_needed = toi_prune_memory_needed, - .print_debug_info = toi_prune_print_debug_stats, - .save_config_info = toi_prune_save_config_info, - .load_config_info = toi_prune_load_config_info, - .storage_needed = toi_prune_storage_needed, - .expected_compression = toi_prune_expected_ratio, - - .pre_atomic_restore = toi_prune_pre_atomic_restore, - .post_atomic_restore = toi_prune_post_atomic_restore, - - .rw_init = toi_prune_rw_init, - .rw_cleanup = toi_prune_rw_cleanup, - - .write_page = toi_prune_write_page, - .read_page = toi_prune_read_page, - - .sysfs_data = sysfs_params, - .num_sysfs_entries = sizeof(sysfs_params) / - sizeof(struct toi_sysfs_data), -}; - -/* ---- Registration ---- */ - -static __init int toi_prune_load(void) -{ - return toi_register_module(&toi_prune_ops); -} - -late_initcall(toi_prune_load); |