File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
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 0000000..4afe66a
--- /dev/null
+++ b/arch/powerpc/include/asm/word-at-a-time.h
@@ -0,0 +1,208 @@
+#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;
+}
+
+static inline unsigned long zero_bytemask(unsigned long mask)
+{
+ return ~1ul << __fls(mask);
+}
+
+#else
+
+#ifdef CONFIG_64BIT
+
+/* unused */
+struct word_at_a_time {
+};
+
+#define WORD_AT_A_TIME_CONSTANTS { }
+
+/* This will give us 0xff for a NULL char and 0x00 elsewhere */
+static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
+{
+ unsigned long ret;
+ unsigned long zero = 0;
+
+ asm("cmpb %0,%1,%2" : "=r" (ret) : "r" (a), "r" (zero));
+ *bits = ret;
+
+ return ret;
+}
+
+static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
+{
+ return bits;
+}
+
+/* Alan Modra's little-endian strlen tail for 64-bit */
+static inline unsigned long create_zero_mask(unsigned long bits)
+{
+ 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)
+ : "b" (bits));
+
+ return leading_zero_bits;
+}
+
+static inline unsigned long find_zero(unsigned long mask)
+{
+ return mask >> 3;
+}
+
+/* This assumes that we never ask for an all 1s bitmask */
+static inline unsigned long zero_bytemask(unsigned long mask)
+{
+ return (1UL << mask) - 1;
+}
+
+#else /* 32-bit case */
+
+struct word_at_a_time {
+ const unsigned long one_bits, high_bits;
+};
+
+#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
+
+/*
+ * 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);
+}
+
+/* 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 /* CONFIG_64BIT */
+
+#endif /* __BIG_ENDIAN__ */
+
+/*
+ * We use load_unaligned_zero() in a selftest, which builds a userspace
+ * program. Some linker scripts seem to discard the .fixup section, so allow
+ * the test code to use a different section name.
+ */
+#ifndef FIXUP_SECTION
+#define FIXUP_SECTION ".fixup"
+#endif
+
+static inline unsigned long load_unaligned_zeropad(const void *addr)
+{
+ unsigned long ret, offset, tmp;
+
+ asm(
+ "1: " PPC_LL "%[ret], 0(%[addr])\n"
+ "2:\n"
+ ".section " FIXUP_SECTION ",\"ax\"\n"
+ "3: "
+#ifdef __powerpc64__
+ "clrrdi %[tmp], %[addr], 3\n\t"
+ "clrlsldi %[offset], %[addr], 61, 3\n\t"
+ "ld %[ret], 0(%[tmp])\n\t"
+#ifdef __BIG_ENDIAN__
+ "sld %[ret], %[ret], %[offset]\n\t"
+#else
+ "srd %[ret], %[ret], %[offset]\n\t"
+#endif
+#else
+ "clrrwi %[tmp], %[addr], 2\n\t"
+ "clrlslwi %[offset], %[addr], 30, 3\n\t"
+ "lwz %[ret], 0(%[tmp])\n\t"
+#ifdef __BIG_ENDIAN__
+ "slw %[ret], %[ret], %[offset]\n\t"
+#else
+ "srw %[ret], %[ret], %[offset]\n\t"
+#endif
+#endif
+ "b 2b\n"
+ ".previous\n"
+ ".section __ex_table,\"a\"\n\t"
+ PPC_LONG_ALIGN "\n\t"
+ PPC_LONG "1b,3b\n"
+ ".previous"
+ : [tmp] "=&b" (tmp), [offset] "=&r" (offset), [ret] "=&r" (ret)
+ : [addr] "b" (addr), "m" (*(unsigned long *)addr));
+
+ return ret;
+}
+
+#undef FIXUP_SECTION
+
+#endif /* _ASM_WORD_AT_A_TIME_H */