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authorStefan Roese <sr@denx.de>2009-03-19 15:35:05 +0100
committerWolfgang Denk <wd@denx.de>2009-03-20 22:39:15 +0100
commit9eefe2a2b37a838558e3d213a9f5519503d0c180 (patch)
treecd6ce359f020615d685d353fc3a20e7e07ac05fc /include/linux/math64.h
parentb1b4e89a0f3b75854c39a62cae41bad56d210adf (diff)
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UBIFS: Implement read-only UBIFS support in U-Boot
The U-Boot UBIFS implementation is largely a direct copy from the current Linux version (2.6.29-rc6). As already done in the UBI version we have an "abstraction layer" to redefine or remove some OS calls (e.g. mutex_lock() ...). This makes it possible to use the original Linux code with very little changes. And by this we can better update to later Linux versions. I removed some of the Linux features that are not used in the U-Boot version (e.g. garbage-collection, write support). Signed-off-by: Stefan Roese <sr@denx.de> CC: Artem Bityutskiy <dedekind@infradead.org> CC: Adrian Hunter <ext-Adrian.Hunter@nokia.com>
Diffstat (limited to 'include/linux/math64.h')
-rw-r--r--include/linux/math64.h85
1 files changed, 85 insertions, 0 deletions
diff --git a/include/linux/math64.h b/include/linux/math64.h
new file mode 100644
index 0000000..6d760d7
--- /dev/null
+++ b/include/linux/math64.h
@@ -0,0 +1,85 @@
+#ifndef _LINUX_MATH64_H
+#define _LINUX_MATH64_H
+
+#include <linux/types.h>
+
+#if BITS_PER_LONG == 64
+
+/**
+ * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
+ *
+ * This is commonly provided by 32bit archs to provide an optimized 64bit
+ * divide.
+ */
+static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
+{
+ *remainder = dividend % divisor;
+ return dividend / divisor;
+}
+
+/**
+ * div_s64_rem - signed 64bit divide with 32bit divisor with remainder
+ */
+static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
+{
+ *remainder = dividend % divisor;
+ return dividend / divisor;
+}
+
+/**
+ * div64_u64 - unsigned 64bit divide with 64bit divisor
+ */
+static inline u64 div64_u64(u64 dividend, u64 divisor)
+{
+ return dividend / divisor;
+}
+
+#elif BITS_PER_LONG == 32
+
+#ifndef div_u64_rem
+static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
+{
+ *remainder = do_div(dividend, divisor);
+ return dividend;
+}
+#endif
+
+#ifndef div_s64_rem
+extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
+#endif
+
+#ifndef div64_u64
+extern u64 div64_u64(u64 dividend, u64 divisor);
+#endif
+
+#endif /* BITS_PER_LONG */
+
+/**
+ * div_u64 - unsigned 64bit divide with 32bit divisor
+ *
+ * This is the most common 64bit divide and should be used if possible,
+ * as many 32bit archs can optimize this variant better than a full 64bit
+ * divide.
+ */
+#ifndef div_u64
+static inline u64 div_u64(u64 dividend, u32 divisor)
+{
+ u32 remainder;
+ return div_u64_rem(dividend, divisor, &remainder);
+}
+#endif
+
+/**
+ * div_s64 - signed 64bit divide with 32bit divisor
+ */
+#ifndef div_s64
+static inline s64 div_s64(s64 dividend, s32 divisor)
+{
+ s32 remainder;
+ return div_s64_rem(dividend, divisor, &remainder);
+}
+#endif
+
+u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder);
+
+#endif /* _LINUX_MATH64_H */