Add a cryptoapi LZF module. Performance in suspending to disk can be
greatly improved by a fast compression algorithm. LZF provides this. It was
donated by Marc Alexander Lehmann under a dual BSD/GPL license.
Signed-off-by: Nigel Cunningham <[email protected]>
crypto/Kconfig | 7 +
crypto/Makefile | 1
crypto/lzf.c | 335 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 343 insertions(+), 0 deletions(-)
diff --git a/crypto/Kconfig b/crypto/Kconfig
index c442f2e..36e0b71 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -316,6 +316,13 @@ config CRYPTO_DEFLATE
You will most probably want this if using IPSec.
+config CRYPTO_LZF
+ tristate "LZF compression algorithm"
+ depends on CRYPTO
+ help
+ This is the LZF algorithm. It is especially useful for Suspend2,
+ because it achieves good compression quickly.
+
config CRYPTO_MICHAEL_MIC
tristate "Michael MIC keyed digest algorithm"
depends on CRYPTO
diff --git a/crypto/Makefile b/crypto/Makefile
index d287b9e..9845a6d 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -30,5 +30,6 @@ obj-$(CONFIG_CRYPTO_ANUBIS) += anubis.o
obj-$(CONFIG_CRYPTO_DEFLATE) += deflate.o
obj-$(CONFIG_CRYPTO_MICHAEL_MIC) += michael_mic.o
obj-$(CONFIG_CRYPTO_CRC32C) += crc32c.o
+obj-$(CONFIG_CRYPTO_LZF) += lzf.o
obj-$(CONFIG_CRYPTO_TEST) += tcrypt.o
diff --git a/crypto/lzf.c b/crypto/lzf.c
new file mode 100644
index 0000000..fce1621
--- /dev/null
+++ b/crypto/lzf.c
@@ -0,0 +1,335 @@
+/*
+ * Cryptoapi LZF compression module.
+ *
+ * Copyright (c) 2004-2005 Nigel Cunningham <[email protected]>
+ *
+ * based on the deflate.c file:
+ *
+ * Copyright (c) 2003 James Morris <[email protected]>
+ *
+ * and upon the LZF compression module donated to the Suspend2 project with
+ * the following copyright:
+ *
+ * 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.
+ * Copyright (c) 2000-2003 Marc Alexander Lehmann <[email protected]>
+ *
+ * Redistribution and use in source and binary forms, with or without modifica-
+ * tion, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
+ * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
+ * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
+ * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * the GNU General Public License version 2 (the "GPL"), in which case the
+ * provisions of the GPL are applicable instead of the above. If you wish to
+ * allow the use of your version of this file only under the terms of the
+ * GPL and not to allow others to use your version of this file under the
+ * BSD license, indicate your decision by deleting the provisions above and
+ * replace them with the notice and other provisions required by the GPL. If
+ * you do not delete the provisions above, a recipient may use your version
+ * of this file under either the BSD or the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/crypto.h>
+#include <linux/err.h>
+#include <linux/vmalloc.h>
+#include <asm/string.h>
+
+struct lzf_ctx {
+ void *hbuf;
+ unsigned int bufofs;
+};
+
+/*
+ * size of hashtable is (1 << hlog) * sizeof (char *)
+ * decompression is independent of the hash table size
+ * the difference between 15 and 14 is very small
+ * for small blocks (and 14 is also faster).
+ * For a low-memory configuration, use hlog == 13;
+ * For best compression, use 15 or 16.
+ */
+static const int hlog = 14;
+
+/*
+ * don't play with this unless you benchmark!
+ * decompression is not dependent on the hash function
+ * the hashing function might seem strange, just believe me
+ * it works ;)
+ */
+static inline u16 first(const u8 *p)
+{
+ return ((p[0]) << 8) + p[1];
+}
+
+static inline u16 next(u8 v, const u8 *p)
+{
+ return ((v) << 8) + p[2];
+}
+
+static inline u32 idx(unsigned int h)
+{
+ return (((h ^ (h << 5)) >> (3*8 - hlog)) + h*3) & ((1 << hlog) - 1);
+}
+
+/*
+ * IDX works because it is very similar to a multiplicative hash, e.g.
+ * (h * 57321 >> (3*8 - hlog))
+ * the next one is also quite good, albeit slow ;)
+ * (int)(cos(h & 0xffffff) * 1e6)
+ */
+
+static const int max_lit = (1 << 5);
+static const int max_off = (1 << 13);
+static const int max_ref = ((1 << 8) + (1 << 3));
+
+/*
+ * compressed format
+ *
+ * 000LLLLL <L+1> ; literal
+ * LLLOOOOO oooooooo ; backref L
+ * 111OOOOO LLLLLLLL oooooooo ; backref L+7
+ *
+ */
+
+static void lzf_compress_exit(void *context)
+{
+ struct lzf_ctx *ctx = (struct lzf_ctx *)context;
+
+ if (ctx->hbuf) {
+ vfree(ctx->hbuf);
+ ctx->hbuf = NULL;
+ }
+}
+
+static int lzf_compress_init(void *context)
+{
+ struct lzf_ctx *ctx = (struct lzf_ctx *)context;
+
+ /* Get LZF ready to go */
+ ctx->hbuf = vmalloc_32((1 << hlog) * sizeof(char *));
+ if (!ctx->hbuf) {
+ printk(KERN_WARNING
+ "Failed to allocate %ld bytes for lzf workspace\n",
+ (long) ((1 << hlog) * sizeof(char *)));
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+static int lzf_compress(void *context, const u8 *in_data, unsigned int in_len,
+ u8 *out_data, unsigned int *out_len)
+{
+ struct lzf_ctx *ctx = (struct lzf_ctx *)context;
+ const u8 **htab = ctx->hbuf;
+ const u8 **hslot;
+ const u8 *ip = in_data;
+ u8 *op = out_data;
+ const u8 *in_end = ip + in_len;
+ u8 *out_end = op + *out_len - 3;
+ const u8 *ref;
+
+ unsigned int hval = first(ip);
+ unsigned long off;
+ int lit = 0;
+
+ memset(htab, 0, sizeof(htab));
+
+ for (;;) {
+ if (ip < in_end - 2) {
+ hval = next(hval, ip);
+ hslot = htab + idx(hval);
+ ref = *hslot;
+ *hslot = ip;
+
+ if ((off = ip - ref - 1) < max_off
+ && ip + 4 < in_end && ref > in_data
+ && *(u16 *) ref == *(u16 *) ip && ref[2] == ip[2]
+ ) {
+ /* match found at *ref++ */
+ unsigned int len = 2;
+ unsigned int maxlen = in_end - ip - len;
+ maxlen = maxlen > max_ref ? max_ref : maxlen;
+
+ do
+ len++;
+ while (len < maxlen && ref[len] == ip[len]);
+
+ if (op + lit + 1 + 3 >= out_end) {
+ *out_len = PAGE_SIZE;
+ return 0;
+ }
+
+ if (lit) {
+ *op++ = lit - 1;
+ lit = -lit;
+ do
+ *op++ = ip[lit];
+ while (++lit);
+ }
+
+ len -= 2;
+ ip++;
+
+ if (len < 7) {
+ *op++ = (off >> 8) + (len << 5);
+ } else {
+ *op++ = (off >> 8) + (7 << 5);
+ *op++ = len - 7;
+ }
+
+ *op++ = off;
+
+ ip += len;
+ hval = first(ip);
+ hval = next(hval, ip);
+ htab[idx(hval)] = ip;
+ ip++;
+ continue;
+ }
+ } else if (ip == in_end)
+ break;
+
+ /* one more literal byte we must copy */
+ lit++;
+ ip++;
+
+ if (lit == max_lit) {
+ if (op + 1 + max_lit >= out_end) {
+ *out_len = PAGE_SIZE;
+ return 0;
+ }
+
+ *op++ = max_lit - 1;
+ memcpy(op, ip - max_lit, max_lit);
+ op += max_lit;
+ lit = 0;
+ }
+ }
+
+ if (lit) {
+ if (op + lit + 1 >= out_end) {
+ *out_len = PAGE_SIZE;
+ return 0;
+ }
+
+ *op++ = lit - 1;
+ lit = -lit;
+ do
+ *op++ = ip[lit];
+ while (++lit);
+ }
+
+ *out_len = op - out_data;
+ return 0;
+}
+
+static int lzf_decompress(void *context, const u8 *src, unsigned int slen,
+ u8 *dst, unsigned int *dlen)
+{
+ u8 const *ip = src;
+ u8 *op = dst;
+ u8 const *const in_end = ip + slen;
+ u8 *const out_end = op + *dlen;
+
+ do {
+ unsigned int ctrl = *ip++;
+
+ if (ctrl < (1 << 5)) { /* literal run */
+ ctrl++;
+
+ if (op + ctrl > out_end) {
+ *dlen = PAGE_SIZE;
+ return 0;
+ }
+ memcpy(op, ip, ctrl);
+ op += ctrl;
+ ip += ctrl;
+ } else { /* back reference */
+
+ unsigned int len = ctrl >> 5;
+
+ u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
+
+ if (len == 7)
+ len += *ip++;
+
+ ref -= *ip++;
+
+ if (op + len + 2 > out_end) {
+ *dlen = PAGE_SIZE;
+ return 0;
+ }
+
+ if (ref < (u8 *) dst) {
+ *dlen = PAGE_SIZE;
+ return 0;
+ }
+
+ *op++ = *ref++;
+ *op++ = *ref++;
+
+ do
+ *op++ = *ref++;
+ while (--len);
+ }
+ }
+ while (op < out_end && ip < in_end);
+
+ *dlen = op - (u8 *) dst;
+ return 0;
+}
+
+static struct crypto_alg alg = {
+ .cra_name = "lzf",
+ .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
+ .cra_ctxsize = 0,
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(alg.cra_list),
+ .cra_u = {.compress = {
+ .coa_init = lzf_compress_init,
+ .coa_exit = lzf_compress_exit,
+ .coa_compress = lzf_compress,
+ .coa_decompress = lzf_decompress}}
+};
+
+static int __init init(void)
+{
+ return crypto_register_alg(&alg);
+}
+
+static void __exit fini(void)
+{
+ crypto_unregister_alg(&alg);
+}
+
+module_init(init);
+module_exit(fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LZF Compression Algorithm");
+MODULE_AUTHOR("Marc Alexander Lehmann & Nigel Cunningham");
--
Nigel Cunningham nigel at suspend2 dot net
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