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Based on 1 normalized pattern(s): 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 either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
240 lines
5.7 KiB
C
240 lines
5.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2014 Sergey Senozhatsky.
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*/
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/wait.h>
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#include <linux/sched.h>
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#include <linux/cpu.h>
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#include <linux/crypto.h>
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#include "zcomp.h"
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static const char * const backends[] = {
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"lzo",
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"lzo-rle",
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#if IS_ENABLED(CONFIG_CRYPTO_LZ4)
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"lz4",
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#endif
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#if IS_ENABLED(CONFIG_CRYPTO_LZ4HC)
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"lz4hc",
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#endif
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#if IS_ENABLED(CONFIG_CRYPTO_842)
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"842",
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#endif
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#if IS_ENABLED(CONFIG_CRYPTO_ZSTD)
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"zstd",
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#endif
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NULL
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};
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static void zcomp_strm_free(struct zcomp_strm *zstrm)
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{
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if (!IS_ERR_OR_NULL(zstrm->tfm))
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crypto_free_comp(zstrm->tfm);
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free_pages((unsigned long)zstrm->buffer, 1);
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kfree(zstrm);
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}
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/*
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* allocate new zcomp_strm structure with ->tfm initialized by
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* backend, return NULL on error
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*/
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static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp)
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{
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struct zcomp_strm *zstrm = kmalloc(sizeof(*zstrm), GFP_KERNEL);
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if (!zstrm)
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return NULL;
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zstrm->tfm = crypto_alloc_comp(comp->name, 0, 0);
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/*
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* allocate 2 pages. 1 for compressed data, plus 1 extra for the
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* case when compressed size is larger than the original one
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*/
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zstrm->buffer = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
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if (IS_ERR_OR_NULL(zstrm->tfm) || !zstrm->buffer) {
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zcomp_strm_free(zstrm);
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zstrm = NULL;
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}
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return zstrm;
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}
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bool zcomp_available_algorithm(const char *comp)
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{
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int i;
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i = __sysfs_match_string(backends, -1, comp);
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if (i >= 0)
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return true;
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/*
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* Crypto does not ignore a trailing new line symbol,
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* so make sure you don't supply a string containing
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* one.
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* This also means that we permit zcomp initialisation
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* with any compressing algorithm known to crypto api.
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*/
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return crypto_has_comp(comp, 0, 0) == 1;
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}
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/* show available compressors */
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ssize_t zcomp_available_show(const char *comp, char *buf)
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{
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bool known_algorithm = false;
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ssize_t sz = 0;
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int i = 0;
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for (; backends[i]; i++) {
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if (!strcmp(comp, backends[i])) {
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known_algorithm = true;
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sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
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"[%s] ", backends[i]);
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} else {
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sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
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"%s ", backends[i]);
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}
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}
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/*
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* Out-of-tree module known to crypto api or a missing
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* entry in `backends'.
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*/
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if (!known_algorithm && crypto_has_comp(comp, 0, 0) == 1)
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sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
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"[%s] ", comp);
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sz += scnprintf(buf + sz, PAGE_SIZE - sz, "\n");
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return sz;
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}
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struct zcomp_strm *zcomp_stream_get(struct zcomp *comp)
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{
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return *get_cpu_ptr(comp->stream);
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}
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void zcomp_stream_put(struct zcomp *comp)
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{
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put_cpu_ptr(comp->stream);
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}
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int zcomp_compress(struct zcomp_strm *zstrm,
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const void *src, unsigned int *dst_len)
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{
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/*
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* Our dst memory (zstrm->buffer) is always `2 * PAGE_SIZE' sized
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* because sometimes we can endup having a bigger compressed data
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* due to various reasons: for example compression algorithms tend
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* to add some padding to the compressed buffer. Speaking of padding,
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* comp algorithm `842' pads the compressed length to multiple of 8
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* and returns -ENOSP when the dst memory is not big enough, which
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* is not something that ZRAM wants to see. We can handle the
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* `compressed_size > PAGE_SIZE' case easily in ZRAM, but when we
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* receive -ERRNO from the compressing backend we can't help it
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* anymore. To make `842' happy we need to tell the exact size of
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* the dst buffer, zram_drv will take care of the fact that
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* compressed buffer is too big.
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*/
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*dst_len = PAGE_SIZE * 2;
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return crypto_comp_compress(zstrm->tfm,
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src, PAGE_SIZE,
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zstrm->buffer, dst_len);
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}
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int zcomp_decompress(struct zcomp_strm *zstrm,
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const void *src, unsigned int src_len, void *dst)
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{
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unsigned int dst_len = PAGE_SIZE;
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return crypto_comp_decompress(zstrm->tfm,
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src, src_len,
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dst, &dst_len);
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}
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int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
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{
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struct zcomp *comp = hlist_entry(node, struct zcomp, node);
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struct zcomp_strm *zstrm;
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if (WARN_ON(*per_cpu_ptr(comp->stream, cpu)))
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return 0;
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zstrm = zcomp_strm_alloc(comp);
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if (IS_ERR_OR_NULL(zstrm)) {
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pr_err("Can't allocate a compression stream\n");
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return -ENOMEM;
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}
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*per_cpu_ptr(comp->stream, cpu) = zstrm;
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return 0;
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}
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int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node)
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{
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struct zcomp *comp = hlist_entry(node, struct zcomp, node);
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struct zcomp_strm *zstrm;
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zstrm = *per_cpu_ptr(comp->stream, cpu);
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if (!IS_ERR_OR_NULL(zstrm))
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zcomp_strm_free(zstrm);
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*per_cpu_ptr(comp->stream, cpu) = NULL;
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return 0;
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}
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static int zcomp_init(struct zcomp *comp)
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{
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int ret;
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comp->stream = alloc_percpu(struct zcomp_strm *);
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if (!comp->stream)
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return -ENOMEM;
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ret = cpuhp_state_add_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
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if (ret < 0)
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goto cleanup;
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return 0;
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cleanup:
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free_percpu(comp->stream);
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return ret;
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}
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void zcomp_destroy(struct zcomp *comp)
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{
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cpuhp_state_remove_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
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free_percpu(comp->stream);
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kfree(comp);
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}
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/*
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* search available compressors for requested algorithm.
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* allocate new zcomp and initialize it. return compressing
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* backend pointer or ERR_PTR if things went bad. ERR_PTR(-EINVAL)
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* if requested algorithm is not supported, ERR_PTR(-ENOMEM) in
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* case of allocation error, or any other error potentially
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* returned by zcomp_init().
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*/
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struct zcomp *zcomp_create(const char *compress)
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{
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struct zcomp *comp;
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int error;
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if (!zcomp_available_algorithm(compress))
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return ERR_PTR(-EINVAL);
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comp = kzalloc(sizeof(struct zcomp), GFP_KERNEL);
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if (!comp)
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return ERR_PTR(-ENOMEM);
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comp->name = compress;
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error = zcomp_init(comp);
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if (error) {
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kfree(comp);
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return ERR_PTR(error);
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}
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return comp;
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}
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