1 files changed, 119 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/word-at-a-time.h b/arch/powerpc/include/asm/word-at-a-time.h
new file mode 100644
index 00000000000..9a5c928bb3c
--- /dev/null
+++ b/arch/powerpc/include/asm/word-at-a-time.h
@@ -0,0 +1,119 @@
+#ifndef _ASM_WORD_AT_A_TIME_H
+#define _ASM_WORD_AT_A_TIME_H
+
+/*
+ * Word-at-a-time interfaces for PowerPC.
+ */
+
+#include <linux/kernel.h>
+#include <asm/asm-compat.h>
+
+#ifdef __BIG_ENDIAN__
+
+struct word_at_a_time {
+	const unsigned long high_bits, low_bits;
+};
+
+#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0xfe) + 1, REPEAT_BYTE(0x7f) }
+
+/* Bit set in the bytes that have a zero */
+static inline long prep_zero_mask(unsigned long val, unsigned long rhs, const struct word_at_a_time *c)
+{
+	unsigned long mask = (val & c->low_bits) + c->low_bits;
+	return ~(mask | rhs);
+}
+
+#define create_zero_mask(mask) (mask)
+
+static inline long find_zero(unsigned long mask)
+{
+	long leading_zero_bits;
+
+	asm (PPC_CNTLZL "%0,%1" : "=r" (leading_zero_bits) : "r" (mask));
+	return leading_zero_bits >> 3;
+}
+
+static inline bool has_zero(unsigned long val, unsigned long *data, const struct word_at_a_time *c)
+{
+	unsigned long rhs = val | c->low_bits;
+	*data = rhs;
+	return (val + c->high_bits) & ~rhs;
+}
+
+#else
+
+struct word_at_a_time {
+	const unsigned long one_bits, high_bits;
+};
+
+#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
+
+#ifdef CONFIG_64BIT
+
+/* Alan Modra's little-endian strlen tail for 64-bit */
+#define create_zero_mask(mask) (mask)
+
+static inline unsigned long find_zero(unsigned long mask)
+{
+	unsigned long leading_zero_bits;
+	long trailing_zero_bit_mask;
+
+	asm ("addi %1,%2,-1\n\t"
+	     "andc %1,%1,%2\n\t"
+	     "popcntd %0,%1"
+	     : "=r" (leading_zero_bits), "=&r" (trailing_zero_bit_mask)
+	     : "r" (mask));
+	return leading_zero_bits >> 3;
+}
+
+#else	/* 32-bit case */
+
+/*
+ * This is largely generic for little-endian machines, but the
+ * optimal byte mask counting is probably going to be something
+ * that is architecture-specific. If you have a reliably fast
+ * bit count instruction, that might be better than the multiply
+ * and shift, for example.
+ */
+
+/* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
+static inline long count_masked_bytes(long mask)
+{
+	/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
+	long a = (0x0ff0001+mask) >> 23;
+	/* Fix the 1 for 00 case */
+	return a & mask;
+}
+
+static inline unsigned long create_zero_mask(unsigned long bits)
+{
+	bits = (bits - 1) & ~bits;
+	return bits >> 7;
+}
+
+static inline unsigned long find_zero(unsigned long mask)
+{
+	return count_masked_bytes(mask);
+}
+
+#endif
+
+/* Return nonzero if it has a zero */
+static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
+{
+	unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
+	*bits = mask;
+	return mask;
+}
+
+static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
+{
+	return bits;
+}
+
+/* The mask we created is directly usable as a bytemask */
+#define zero_bytemask(mask) (mask)
+
+#endif
+
+#endif /* _ASM_WORD_AT_A_TIME_H */