[PATCH v2] pstore: add lz4hc and 842 compression support

[Geliang Tang]

From: Geliang Tang <geliangtang@xxxxxxxxx>

Currently, pstore has supported three compression algorithms: zlib,
lzo and lz4. This patch added two more compression algorithms: lz4hc
and 842.

Signed-off-by: Geliang Tang <geliangtang@xxxxxxxxx>
---
Changes in v2:
 fix checkpatch.pl WARNING:
 please write a paragraph that describes the config symbol fully
---
 fs/pstore/Kconfig    |  25 ++++++++++
 fs/pstore/platform.c | 128 +++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 138 insertions(+), 15 deletions(-)

diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index b42e5bd..cf97a3e 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -39,6 +39,31 @@ config PSTORE_LZ4_COMPRESS
         select LZ4_DECOMPRESS
         help
           This option enables LZ4 compression algorithm support.
+
+config PSTORE_LZ4HC_COMPRESS
+	bool "LZ4HC"
+	select LZ4HC_COMPRESS
+	select LZ4_DECOMPRESS
+	help
+	  This option enables LZ4 high compression mode algorithm.
+
+	  Currently, pstore has supported five compression algorithms:
+	  zlib, lzo, lz4, lz4hc and 842.
+
+	  The default compression algorithm is zlib.
+
+config PSTORE_842_COMPRESS
+	bool "842"
+	select 842_COMPRESS
+	select 842_DECOMPRESS
+	help
+	  This option enables 842 compression algorithm support.
+
+	  Currently, pstore has supported five compression algorithms:
+	  zlib, lzo, lz4, lz4hc and 842.
+
+	  The default compression algorithm is zlib.
+
 endchoice
 
 config PSTORE_CONSOLE
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index ec7199e..def0210 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -34,9 +34,12 @@
 #ifdef CONFIG_PSTORE_LZO_COMPRESS
 #include <linux/lzo.h>
 #endif
-#ifdef CONFIG_PSTORE_LZ4_COMPRESS
+#if defined(CONFIG_PSTORE_LZ4_COMPRESS) || defined(CONFIG_PSTORE_LZ4HC_COMPRESS)
 #include <linux/lz4.h>
 #endif
+#ifdef CONFIG_PSTORE_842_COMPRESS
+#include <linux/sw842.h>
+#endif
 #include <linux/string.h>
 #include <linux/timer.h>
 #include <linux/slab.h>
@@ -337,20 +340,7 @@ static const struct pstore_zbackend backend_lzo = {
 };
 #endif
 
-#ifdef CONFIG_PSTORE_LZ4_COMPRESS
-static int compress_lz4(const void *in, void *out, size_t inlen, size_t outlen)
-{
-	int ret;
-
-	ret = LZ4_compress_default(in, out, inlen, outlen, workspace);
-	if (!ret) {
-		pr_err("LZ4_compress_default error; compression failed!\n");
-		return -EIO;
-	}
-
-	return ret;
-}
-
+#if defined(CONFIG_PSTORE_LZ4_COMPRESS) || defined(CONFIG_PSTORE_LZ4HC_COMPRESS)
 static int decompress_lz4(void *in, void *out, size_t inlen, size_t outlen)
 {
 	int ret;
@@ -392,6 +382,21 @@ static void free_lz4(void)
 	big_oops_buf = NULL;
 	big_oops_buf_sz = 0;
 }
+#endif
+
+#ifdef CONFIG_PSTORE_LZ4_COMPRESS
+static int compress_lz4(const void *in, void *out, size_t inlen, size_t outlen)
+{
+	int ret;
+
+	ret = LZ4_compress_default(in, out, inlen, outlen, workspace);
+	if (!ret) {
+		pr_err("LZ4_compress_default error; compression failed!\n");
+		return -EIO;
+	}
+
+	return ret;
+}
 
 static const struct pstore_zbackend backend_lz4 = {
 	.compress	= compress_lz4,
@@ -402,6 +407,95 @@ static const struct pstore_zbackend backend_lz4 = {
 };
 #endif
 
+#ifdef CONFIG_PSTORE_LZ4HC_COMPRESS
+static int compress_lz4hc(const void *in, void *out,
+			  size_t inlen, size_t outlen)
+{
+	int ret;
+
+	ret = LZ4_compress_HC(in, out, inlen, outlen,
+			      LZ4HC_DEFAULT_CLEVEL, workspace);
+	if (!ret) {
+		pr_err("LZ4_compress_HC error; compression failed!\n");
+		return -EIO;
+	}
+
+	return ret;
+}
+
+static const struct pstore_zbackend backend_lz4hc = {
+	.compress	= compress_lz4hc,
+	.decompress	= decompress_lz4,
+	.allocate	= allocate_lz4,
+	.free		= free_lz4,
+	.name		= "lz4hc",
+};
+#endif
+
+#ifdef CONFIG_PSTORE_842_COMPRESS
+static int compress_842(const void *in, void *out, size_t inlen, size_t outlen)
+{
+	int ret;
+	unsigned int len;
+
+	ret = sw842_compress(in, inlen, out, &len, workspace);
+	if (!ret) {
+		pr_err("sw842_compress error; compression failed!\n");
+		return -EIO;
+	}
+	outlen = len;
+
+	return ret;
+}
+
+static int decompress_842(void *in, void *out, size_t inlen, size_t outlen)
+{
+	int ret;
+	unsigned int len;
+
+	ret = sw842_decompress(in, inlen, out, &len);
+	if (ret < 0) {
+		pr_err("sw842_decompress error, ret = %d!\n", ret);
+		return -EIO;
+	}
+	outlen = len;
+
+	return ret;
+}
+
+static void allocate_842(void)
+{
+	big_oops_buf_sz = psinfo->bufsize * 2;
+	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
+	if (big_oops_buf) {
+		workspace = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
+		if (!workspace) {
+			kfree(big_oops_buf);
+			big_oops_buf = NULL;
+		}
+	} else {
+		pr_err("No memory for uncompressed data; skipping compression\n");
+		workspace = NULL;
+	}
+}
+
+static void free_842(void)
+{
+	kfree(workspace);
+	kfree(big_oops_buf);
+	big_oops_buf = NULL;
+	big_oops_buf_sz = 0;
+}
+
+static const struct pstore_zbackend backend_842 = {
+	.compress	= compress_842,
+	.decompress	= decompress_842,
+	.allocate	= allocate_842,
+	.free		= free_842,
+	.name		= "842",
+};
+#endif
+
 static const struct pstore_zbackend *zbackend =
 #if defined(CONFIG_PSTORE_ZLIB_COMPRESS)
 	&backend_zlib;
@@ -409,6 +503,10 @@ static const struct pstore_zbackend *zbackend =
 	&backend_lzo;
 #elif defined(CONFIG_PSTORE_LZ4_COMPRESS)
 	&backend_lz4;
+#elif defined(CONFIG_PSTORE_LZ4HC_COMPRESS)
+	&backend_lz4hc;
+#elif defined(CONFIG_PSTORE_842_COMPRESS)
+	&backend_842;
 #else
 	NULL;
 #endif
-- 
2.9.3