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Diffstat (limited to 'arch/cris/include/arch-v32/arch/bitops.h')
-rw-r--r--arch/cris/include/arch-v32/arch/bitops.h64
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/cris/include/arch-v32/arch/bitops.h b/arch/cris/include/arch-v32/arch/bitops.h
new file mode 100644
index 000000000000..147689d6b624
--- /dev/null
+++ b/arch/cris/include/arch-v32/arch/bitops.h
@@ -0,0 +1,64 @@
+#ifndef _ASM_CRIS_ARCH_BITOPS_H
+#define _ASM_CRIS_ARCH_BITOPS_H
+
+/*
+ * Helper functions for the core of the ff[sz] functions. They compute the
+ * number of leading zeroes of a bits-in-byte, byte-in-word and
+ * word-in-dword-swapped number. They differ in that the first function also
+ * inverts all bits in the input.
+ */
+
+static inline unsigned long
+cris_swapnwbrlz(unsigned long w)
+{
+ unsigned long res;
+
+ __asm__ __volatile__ ("swapnwbr %0\n\t"
+ "lz %0,%0"
+ : "=r" (res) : "0" (w));
+
+ return res;
+}
+
+static inline unsigned long
+cris_swapwbrlz(unsigned long w)
+{
+ unsigned long res;
+
+ __asm__ __volatile__ ("swapwbr %0\n\t"
+ "lz %0,%0"
+ : "=r" (res) : "0" (w));
+
+ return res;
+}
+
+/*
+ * Find First Zero in word. Undefined if no zero exist, so the caller should
+ * check against ~0 first.
+ */
+static inline unsigned long
+ffz(unsigned long w)
+{
+ return cris_swapnwbrlz(w);
+}
+
+/*
+ * Find First Set bit in word. Undefined if no 1 exist, so the caller
+ * should check against 0 first.
+ */
+static inline unsigned long
+__ffs(unsigned long w)
+{
+ return cris_swapnwbrlz(~w);
+}
+
+/*
+ * Find First Bit that is set.
+ */
+static inline unsigned long
+kernel_ffs(unsigned long w)
+{
+ return w ? cris_swapwbrlz (w) + 1 : 0;
+}
+
+#endif /* _ASM_CRIS_ARCH_BITOPS_H */