Add LZO decompressor support

This patch adds LZO decompression support to U-Boot. It is needed for
the upcoming UBIFS support, since UBIFS uses LZO as default compressor/
decompressor. Since we only support read-only in UBIFS, only the
decompressor is needed.

All this is copied with minor changes from the current Linux kernel
version (2.6.28-rc8).

This patch only implements this LZO decompressor support for PPC.
Other platforms using UBIFS will have to add the required
"include/asm/unaligned.h" as well. It should be fairly easy to copy this
from the Linux source tree as I have done it for PPC in this patch.

Signed-off-by: Stefan Roese <sr@denx.de>

4 files changed, 197 insertions, 0 deletions

diff --git a/include/asm-ppc/unaligned.h b/include/asm-ppc/unaligned.h
new file mode 100644
index 0000000000..5f1b1e3c21
--- /dev/null
+++ b/include/asm-ppc/unaligned.h
@@ -0,0 +1,16 @@
+#ifndef _ASM_POWERPC_UNALIGNED_H
+#define _ASM_POWERPC_UNALIGNED_H
+
+#ifdef __KERNEL__
+
+/*
+ * The PowerPC can do unaligned accesses itself in big endian mode.
+ */
+#include <linux/unaligned/access_ok.h>
+#include <linux/unaligned/generic.h>
+
+#define get_unaligned	__get_unaligned_be
+#define put_unaligned	__put_unaligned_be
+
+#endif	/* __KERNEL__ */
+#endif	/* _ASM_POWERPC_UNALIGNED_H */
diff --git a/include/linux/lzo.h b/include/linux/lzo.h
new file mode 100644
index 0000000000..d793497ec1
--- /dev/null
+++ b/include/linux/lzo.h
@@ -0,0 +1,44 @@
+#ifndef __LZO_H__
+#define __LZO_H__
+/*
+ *  LZO Public Kernel Interface
+ *  A mini subset of the LZO real-time data compression library
+ *
+ *  Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <markus@oberhumer.com>
+ *
+ *  The full LZO package can be found at:
+ *  http://www.oberhumer.com/opensource/lzo/
+ *
+ *  Changed for kernel use by:
+ *  Nitin Gupta <nitingupta910@gmail.com>
+ *  Richard Purdie <rpurdie@openedhand.com>
+ */
+
+#define LZO1X_MEM_COMPRESS	(16384 * sizeof(unsigned char *))
+#define LZO1X_1_MEM_COMPRESS	LZO1X_MEM_COMPRESS
+
+#define lzo1x_worst_compress(x) ((x) + ((x) / 16) + 64 + 3)
+
+/* This requires 'workmem' of size LZO1X_1_MEM_COMPRESS */
+int lzo1x_1_compress(const unsigned char *src, size_t src_len,
+			unsigned char *dst, size_t *dst_len, void *wrkmem);
+
+/* safe decompression with overrun testing */
+int lzo1x_decompress_safe(const unsigned char *src, size_t src_len,
+			unsigned char *dst, size_t *dst_len);
+
+/*
+ * Return values (< 0 = Error)
+ */
+#define LZO_E_OK			0
+#define LZO_E_ERROR			(-1)
+#define LZO_E_OUT_OF_MEMORY		(-2)
+#define LZO_E_NOT_COMPRESSIBLE		(-3)
+#define LZO_E_INPUT_OVERRUN		(-4)
+#define LZO_E_OUTPUT_OVERRUN		(-5)
+#define LZO_E_LOOKBEHIND_OVERRUN	(-6)
+#define LZO_E_EOF_NOT_FOUND		(-7)
+#define LZO_E_INPUT_NOT_CONSUMED	(-8)
+#define LZO_E_NOT_YET_IMPLEMENTED	(-9)
+
+#endif
diff --git a/include/linux/unaligned/access_ok.h b/include/linux/unaligned/access_ok.h
new file mode 100644
index 0000000000..5f46eee23c
--- /dev/null
+++ b/include/linux/unaligned/access_ok.h
@@ -0,0 +1,66 @@
+#ifndef _LINUX_UNALIGNED_ACCESS_OK_H
+#define _LINUX_UNALIGNED_ACCESS_OK_H
+
+#include <asm/byteorder.h>
+
+static inline u16 get_unaligned_le16(const void *p)
+{
+	return le16_to_cpup((__le16 *)p);
+}
+
+static inline u32 get_unaligned_le32(const void *p)
+{
+	return le32_to_cpup((__le32 *)p);
+}
+
+static inline u64 get_unaligned_le64(const void *p)
+{
+	return le64_to_cpup((__le64 *)p);
+}
+
+static inline u16 get_unaligned_be16(const void *p)
+{
+	return be16_to_cpup((__be16 *)p);
+}
+
+static inline u32 get_unaligned_be32(const void *p)
+{
+	return be32_to_cpup((__be32 *)p);
+}
+
+static inline u64 get_unaligned_be64(const void *p)
+{
+	return be64_to_cpup((__be64 *)p);
+}
+
+static inline void put_unaligned_le16(u16 val, void *p)
+{
+	*((__le16 *)p) = cpu_to_le16(val);
+}
+
+static inline void put_unaligned_le32(u32 val, void *p)
+{
+	*((__le32 *)p) = cpu_to_le32(val);
+}
+
+static inline void put_unaligned_le64(u64 val, void *p)
+{
+	*((__le64 *)p) = cpu_to_le64(val);
+}
+
+static inline void put_unaligned_be16(u16 val, void *p)
+{
+	*((__be16 *)p) = cpu_to_be16(val);
+}
+
+static inline void put_unaligned_be32(u32 val, void *p)
+{
+	*((__be32 *)p) = cpu_to_be32(val);
+}
+
+static inline void put_unaligned_be64(u64 val, void *p)
+{
+	*((__be64 *)p) = cpu_to_be64(val);
+}
+
+#endif /* _LINUX_UNALIGNED_ACCESS_OK_H */
diff --git a/include/linux/unaligned/generic.h b/include/linux/unaligned/generic.h
new file mode 100644
index 0000000000..cc688e1eb1
--- /dev/null
+++ b/include/linux/unaligned/generic.h
@@ -0,0 +1,71 @@
+#ifndef _LINUX_UNALIGNED_GENERIC_H
+#define _LINUX_UNALIGNED_GENERIC_H
+
+/* define __force to nothing in U-Boot */
+#define __force
+
+/*
+ * Cause a link-time error if we try an unaligned access other than
+ * 1,2,4 or 8 bytes long
+ */
+extern void __bad_unaligned_access_size(void);
+
+#define __get_unaligned_le(ptr) ((__force typeof(*(ptr)))({			\
+	__builtin_choose_expr(sizeof(*(ptr)) == 1, *(ptr),			\
+	__builtin_choose_expr(sizeof(*(ptr)) == 2, get_unaligned_le16((ptr)),	\
+	__builtin_choose_expr(sizeof(*(ptr)) == 4, get_unaligned_le32((ptr)),	\
+	__builtin_choose_expr(sizeof(*(ptr)) == 8, get_unaligned_le64((ptr)),	\
+	__bad_unaligned_access_size()))));					\
+	}))
+
+#define __get_unaligned_be(ptr) ((__force typeof(*(ptr)))({			\
+	__builtin_choose_expr(sizeof(*(ptr)) == 1, *(ptr),			\
+	__builtin_choose_expr(sizeof(*(ptr)) == 2, get_unaligned_be16((ptr)),	\
+	__builtin_choose_expr(sizeof(*(ptr)) == 4, get_unaligned_be32((ptr)),	\
+	__builtin_choose_expr(sizeof(*(ptr)) == 8, get_unaligned_be64((ptr)),	\
+	__bad_unaligned_access_size()))));					\
+	}))
+
+#define __put_unaligned_le(val, ptr) ({					\
+	void *__gu_p = (ptr);						\
+	switch (sizeof(*(ptr))) {					\
+	case 1:								\
+		*(u8 *)__gu_p = (__force u8)(val);			\
+		break;							\
+	case 2:								\
+		put_unaligned_le16((__force u16)(val), __gu_p);		\
+		break;							\
+	case 4:								\
+		put_unaligned_le32((__force u32)(val), __gu_p);		\
+		break;							\
+	case 8:								\
+		put_unaligned_le64((__force u64)(val), __gu_p);		\
+		break;							\
+	default:							\
+		__bad_unaligned_access_size();				\
+		break;							\
+	}								\
+	(void)0; })
+
+#define __put_unaligned_be(val, ptr) ({					\
+	void *__gu_p = (ptr);						\
+	switch (sizeof(*(ptr))) {					\
+	case 1:								\
+		*(u8 *)__gu_p = (__force u8)(val);			\
+		break;							\
+	case 2:								\
+		put_unaligned_be16((__force u16)(val), __gu_p);		\
+		break;							\
+	case 4:								\
+		put_unaligned_be32((__force u32)(val), __gu_p);		\
+		break;							\
+	case 8:								\
+		put_unaligned_be64((__force u64)(val), __gu_p);		\
+		break;							\
+	default:							\
+		__bad_unaligned_access_size();				\
+		break;							\
+	}								\
+	(void)0; })
+
+#endif /* _LINUX_UNALIGNED_GENERIC_H */