powerpc: ppc64le optimised word at a time

[cascardo/linux.git] / arch / powerpc / include / asm / word-at-a-time.h

diff --git a/arch/powerpc/include/asm/word-at-a-time.h b/arch/powerpc/include/asm/word-at-a-time.h
index 9a5c928..5b3a903 100644 (file)
--- a/arch/powerpc/include/asm/word-at-a-time.h
+++ b/arch/powerpc/include/asm/word-at-a-time.h
@@ -42,32 +42,65 @@ static inline bool has_zero(unsigned long val, unsigned long *data, const struct
 
 #else
 
+#ifdef CONFIG_64BIT
+
+/* unused */
 struct word_at_a_time {
-       const unsigned long one_bits, high_bits;
 };
 
-#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
+#define WORD_AT_A_TIME_CONSTANTS { }
 
-#ifdef CONFIG_64BIT
+/* 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;
 
-/* Alan Modra's little-endian strlen tail for 64-bit */
-#define create_zero_mask(mask) (mask)
+       asm("cmpb %0,%1,%2" : "=r" (ret) : "r" (a), "r" (zero));
+       *bits = ret;
 
-static inline unsigned long find_zero(unsigned long mask)
+       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)
-            : "r" (mask));
-       return leading_zero_bits >> 3;
+       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" (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
@@ -96,8 +129,6 @@ 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)
 {
@@ -114,6 +145,59 @@ static inline unsigned long prep_zero_mask(unsigned long a, unsigned long 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 */