diff options
Diffstat (limited to 'kernel/power/tuxonice_compress.c')
| -rw-r--r-- | kernel/power/tuxonice_compress.c | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/kernel/power/tuxonice_compress.c b/kernel/power/tuxonice_compress.c new file mode 100644 index 000000000..84b85226d --- /dev/null +++ b/kernel/power/tuxonice_compress.c @@ -0,0 +1,452 @@ +/* + * kernel/power/compression.c + * + * Copyright (C) 2003-2015 Nigel Cunningham (nigel at nigelcunningham com au) + * + * This file is released under the GPLv2. + * + * This file contains data compression routines for TuxOnIce, + * using cryptoapi. + */ + +#include <linux/suspend.h> +#include <linux/highmem.h> +#include <linux/vmalloc.h> +#include <linux/crypto.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" + +static int toi_expected_compression; + +static struct toi_module_ops toi_compression_ops; +static struct toi_module_ops *next_driver; + +static char toi_compressor_name[32] = "lzo"; + +static DEFINE_MUTEX(stats_lock); + +struct cpu_context { + u8 *page_buffer; + struct crypto_comp *transform; + unsigned int len; + u8 *buffer_start; + u8 *output_buffer; +}; + +#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_compress_crypto_prepare(void) +{ + int cpu; + + if (!*toi_compressor_name) { + printk(KERN_INFO "TuxOnIce: Compression enabled but no " + "compressor name set.\n"); + return 1; + } + + for_each_online_cpu(cpu) { + struct cpu_context *this = &per_cpu(contexts, cpu); + this->transform = crypto_alloc_comp(toi_compressor_name, 0, 0); + if (IS_ERR(this->transform)) { + printk(KERN_INFO "TuxOnIce: Failed to initialise the " + "%s compression transform.\n", + toi_compressor_name); + this->transform = NULL; + return 1; + } + + this->page_buffer = + (char *) toi_get_zeroed_page(16, TOI_ATOMIC_GFP); + + if (!this->page_buffer) { + printk(KERN_ERR + "Failed to allocate a page buffer for TuxOnIce " + "compression driver.\n"); + return -ENOMEM; + } + + this->output_buffer = + (char *) vmalloc_32(OUT_BUF_SIZE); + + if (!this->output_buffer) { + printk(KERN_ERR + "Failed to allocate a output buffer for TuxOnIce " + "compression driver.\n"); + return -ENOMEM; + } + } + + return 0; +} + +static int toi_compress_rw_cleanup(int writing) +{ + int cpu; + + for_each_online_cpu(cpu) { + struct cpu_context *this = &per_cpu(contexts, cpu); + if (this->transform) { + crypto_free_comp(this->transform); + this->transform = NULL; + } + + if (this->page_buffer) + toi_free_page(16, (unsigned long) this->page_buffer); + + this->page_buffer = NULL; + + if (this->output_buffer) + vfree(this->output_buffer); + + this->output_buffer = NULL; + } + + return 0; +} + +/* + * toi_compress_init + */ + +static int toi_compress_init(int toi_or_resume) +{ + if (!toi_or_resume) + return 0; + + toi_compress_bytes_in = 0; + toi_compress_bytes_out = 0; + + next_driver = toi_get_next_filter(&toi_compression_ops); + + return next_driver ? 0 : -ECHILD; +} + +/* + * toi_compress_rw_init() + */ + +static int toi_compress_rw_init(int rw, int stream_number) +{ + if (toi_compress_crypto_prepare()) { + printk(KERN_ERR "Failed to initialise compression " + "algorithm.\n"); + if (rw == READ) { + printk(KERN_INFO "Unable to read the image.\n"); + return -ENODEV; + } else { + printk(KERN_INFO "Continuing without " + "compressing the image.\n"); + toi_compression_ops.enabled = 0; + } + } + + return 0; +} + +/* + * toi_compress_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 compressed. + * + * 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_compress_write_page(unsigned long index, int buf_type, + void *buffer_page, unsigned int buf_size) +{ + int ret = 0, cpu = smp_processor_id(); + struct cpu_context *ctx = &per_cpu(contexts, cpu); + u8* output_buffer = buffer_page; + int output_len = buf_size; + int out_buf_type = buf_type; + + if (ctx->transform) { + + ctx->buffer_start = TOI_MAP(buf_type, buffer_page); + ctx->len = OUT_BUF_SIZE; + + ret = crypto_comp_compress(ctx->transform, + ctx->buffer_start, buf_size, + ctx->output_buffer, &ctx->len); + + TOI_UNMAP(buf_type, buffer_page); + + toi_message(TOI_COMPRESS, TOI_VERBOSE, 0, + "CPU %d, index %lu: %d bytes", + cpu, index, ctx->len); + + if (!ret && ctx->len < buf_size) { /* some compression */ + output_buffer = ctx->output_buffer; + output_len = ctx->len; + out_buf_type = TOI_VIRT; + } + + } + + mutex_lock(&stats_lock); + + toi_compress_bytes_in += buf_size; + toi_compress_bytes_out += output_len; + + mutex_unlock(&stats_lock); + + if (!ret) + ret = next_driver->write_page(index, out_buf_type, + output_buffer, output_len); + + return ret; +} + +/* + * toi_compress_read_page() + * @buffer_page: struct page *. Pointer to a buffer of size PAGE_SIZE. + * + * Retrieve data from later modules and decompress it until the input buffer + * is filled. + * Zero if successful. Error condition from me or from downstream on failure. + */ +static int toi_compress_read_page(unsigned long *index, int buf_type, + void *buffer_page, unsigned int *buf_size) +{ + int ret, cpu = smp_processor_id(); + unsigned int len; + unsigned int outlen = PAGE_SIZE; + char *buffer_start; + struct cpu_context *ctx = &per_cpu(contexts, cpu); + + if (!ctx->transform) + return next_driver->read_page(index, TOI_PAGE, buffer_page, + buf_size); + + /* + * All our reads must be synchronous - we can't decompress + * data that hasn't been read yet. + */ + + ret = next_driver->read_page(index, TOI_VIRT, ctx->page_buffer, &len); + + buffer_start = kmap(buffer_page); + + /* Error or uncompressed data */ + if (ret || len == PAGE_SIZE) { + memcpy(buffer_start, ctx->page_buffer, len); + goto out; + } + + ret = crypto_comp_decompress( + ctx->transform, + ctx->page_buffer, + len, buffer_start, &outlen); + + toi_message(TOI_COMPRESS, TOI_VERBOSE, 0, + "CPU %d, index %lu: %d=>%d (%d).", + cpu, *index, len, outlen, ret); + + if (ret) + abort_hibernate(TOI_FAILED_IO, + "Compress_read returned %d.\n", ret); + else if (outlen != PAGE_SIZE) { + abort_hibernate(TOI_FAILED_IO, + "Decompression yielded %d bytes instead of %ld.\n", + outlen, PAGE_SIZE); + printk(KERN_ERR "Decompression yielded %d bytes instead of " + "%ld.\n", outlen, PAGE_SIZE); + ret = -EIO; + *buf_size = outlen; + } +out: + TOI_UNMAP(buf_type, buffer_page); + return ret; +} + +/* + * toi_compress_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_compress_print_debug_stats(char *buffer, int size) +{ + unsigned long pages_in = toi_compress_bytes_in >> PAGE_SHIFT, + pages_out = toi_compress_bytes_out >> PAGE_SHIFT; + int len; + + /* Output the compression ratio achieved. */ + if (*toi_compressor_name) + len = scnprintf(buffer, size, "- Compressor is '%s'.\n", + toi_compressor_name); + else + len = scnprintf(buffer, size, "- Compressor is not set.\n"); + + if (pages_in) + len += scnprintf(buffer+len, size - len, " Compressed " + "%lu bytes into %lu (%ld percent compression).\n", + toi_compress_bytes_in, + toi_compress_bytes_out, + (pages_in - pages_out) * 100 / pages_in); + return len; +} + +/* + * toi_compress_compression_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_compress_memory_needed(void) +{ + return 2 * PAGE_SIZE; +} + +static int toi_compress_storage_needed(void) +{ + return 2 * sizeof(unsigned long) + 2 * sizeof(int) + + strlen(toi_compressor_name) + 1; +} + +/* + * toi_compress_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_compress_save_config_info(char *buffer) +{ + int len = strlen(toi_compressor_name) + 1, offset = 0; + + *((unsigned long *) buffer) = toi_compress_bytes_in; + offset += sizeof(unsigned long); + *((unsigned long *) (buffer + offset)) = toi_compress_bytes_out; + offset += sizeof(unsigned long); + *((int *) (buffer + offset)) = toi_expected_compression; + offset += sizeof(int); + *((int *) (buffer + offset)) = len; + offset += sizeof(int); + strncpy(buffer + offset, toi_compressor_name, len); + return offset + len; +} + +/* toi_compress_load_config_info + * @buffer: Pointer to the start of the data. + * @size: Number of bytes that were saved. + * + * Description: Reload information needed for decompressing the image at + * resume time. + */ +static void toi_compress_load_config_info(char *buffer, int size) +{ + int len, offset = 0; + + toi_compress_bytes_in = *((unsigned long *) buffer); + offset += sizeof(unsigned long); + toi_compress_bytes_out = *((unsigned long *) (buffer + offset)); + offset += sizeof(unsigned long); + toi_expected_compression = *((int *) (buffer + offset)); + offset += sizeof(int); + len = *((int *) (buffer + offset)); + offset += sizeof(int); + strncpy(toi_compressor_name, buffer + offset, len); +} + +static void toi_compress_pre_atomic_restore(struct toi_boot_kernel_data *bkd) +{ + bkd->compress_bytes_in = toi_compress_bytes_in; + bkd->compress_bytes_out = toi_compress_bytes_out; +} + +static void toi_compress_post_atomic_restore(struct toi_boot_kernel_data *bkd) +{ + toi_compress_bytes_in = bkd->compress_bytes_in; + toi_compress_bytes_out = bkd->compress_bytes_out; +} + +/* + * toi_expected_compression_ratio + * + * Description: Returns the expected ratio between data passed into this module + * and the amount of data output when writing. + * Returns: 100 if the module is disabled. Otherwise the value set by the + * user via our sysfs entry. + */ + +static int toi_compress_expected_ratio(void) +{ + if (!toi_compression_ops.enabled) + return 100; + else + return 100 - toi_expected_compression; +} + +/* + * data for our sysfs entries. + */ +static struct toi_sysfs_data sysfs_params[] = { + SYSFS_INT("expected_compression", SYSFS_RW, &toi_expected_compression, + 0, 99, 0, NULL), + SYSFS_INT("enabled", SYSFS_RW, &toi_compression_ops.enabled, 0, 1, 0, + NULL), + SYSFS_STRING("algorithm", SYSFS_RW, toi_compressor_name, 31, 0, NULL), +}; + +/* + * Ops structure. + */ +static struct toi_module_ops toi_compression_ops = { + .type = FILTER_MODULE, + .name = "compression", + .directory = "compression", + .module = THIS_MODULE, + .initialise = toi_compress_init, + .memory_needed = toi_compress_memory_needed, + .print_debug_info = toi_compress_print_debug_stats, + .save_config_info = toi_compress_save_config_info, + .load_config_info = toi_compress_load_config_info, + .storage_needed = toi_compress_storage_needed, + .expected_compression = toi_compress_expected_ratio, + + .pre_atomic_restore = toi_compress_pre_atomic_restore, + .post_atomic_restore = toi_compress_post_atomic_restore, + + .rw_init = toi_compress_rw_init, + .rw_cleanup = toi_compress_rw_cleanup, + + .write_page = toi_compress_write_page, + .read_page = toi_compress_read_page, + + .sysfs_data = sysfs_params, + .num_sysfs_entries = sizeof(sysfs_params) / + sizeof(struct toi_sysfs_data), +}; + +/* ---- Registration ---- */ + +static __init int toi_compress_load(void) +{ + return toi_register_module(&toi_compression_ops); +} + +late_initcall(toi_compress_load); |