207 lines
4.8 KiB
C
207 lines
4.8 KiB
C
#ifndef _ASM_WORD_AT_A_TIME_H
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#define _ASM_WORD_AT_A_TIME_H
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/*
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* Word-at-a-time interfaces for PowerPC.
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*/
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#include <linux/kernel.h>
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#include <asm/asm-compat.h>
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#include <asm/extable.h>
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#ifdef __BIG_ENDIAN__
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struct word_at_a_time {
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const unsigned long high_bits, low_bits;
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};
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#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0xfe) + 1, REPEAT_BYTE(0x7f) }
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/* Bit set in the bytes that have a zero */
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static inline long prep_zero_mask(unsigned long val, unsigned long rhs, const struct word_at_a_time *c)
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{
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unsigned long mask = (val & c->low_bits) + c->low_bits;
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return ~(mask | rhs);
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}
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#define create_zero_mask(mask) (mask)
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static inline long find_zero(unsigned long mask)
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{
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long leading_zero_bits;
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asm (PPC_CNTLZL "%0,%1" : "=r" (leading_zero_bits) : "r" (mask));
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return leading_zero_bits >> 3;
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}
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static inline bool has_zero(unsigned long val, unsigned long *data, const struct word_at_a_time *c)
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{
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unsigned long rhs = val | c->low_bits;
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*data = rhs;
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return (val + c->high_bits) & ~rhs;
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}
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static inline unsigned long zero_bytemask(unsigned long mask)
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{
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return ~1ul << __fls(mask);
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}
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#else
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#ifdef CONFIG_64BIT
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/* unused */
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struct word_at_a_time {
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};
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#define WORD_AT_A_TIME_CONSTANTS { }
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/* This will give us 0xff for a NULL char and 0x00 elsewhere */
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static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
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{
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unsigned long ret;
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unsigned long zero = 0;
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asm("cmpb %0,%1,%2" : "=r" (ret) : "r" (a), "r" (zero));
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*bits = ret;
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return ret;
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}
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static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
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{
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return bits;
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}
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/* Alan Modra's little-endian strlen tail for 64-bit */
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static inline unsigned long create_zero_mask(unsigned long bits)
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{
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unsigned long leading_zero_bits;
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long trailing_zero_bit_mask;
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asm("addi %1,%2,-1\n\t"
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"andc %1,%1,%2\n\t"
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"popcntd %0,%1"
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: "=r" (leading_zero_bits), "=&r" (trailing_zero_bit_mask)
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: "b" (bits));
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return leading_zero_bits;
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}
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static inline unsigned long find_zero(unsigned long mask)
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{
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return mask >> 3;
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}
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/* This assumes that we never ask for an all 1s bitmask */
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static inline unsigned long zero_bytemask(unsigned long mask)
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{
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return (1UL << mask) - 1;
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}
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#else /* 32-bit case */
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struct word_at_a_time {
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const unsigned long one_bits, high_bits;
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};
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#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
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/*
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* This is largely generic for little-endian machines, but the
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* optimal byte mask counting is probably going to be something
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* that is architecture-specific. If you have a reliably fast
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* bit count instruction, that might be better than the multiply
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* and shift, for example.
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*/
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/* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
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static inline long count_masked_bytes(long mask)
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{
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/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
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long a = (0x0ff0001+mask) >> 23;
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/* Fix the 1 for 00 case */
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return a & mask;
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}
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static inline unsigned long create_zero_mask(unsigned long bits)
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{
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bits = (bits - 1) & ~bits;
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return bits >> 7;
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}
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static inline unsigned long find_zero(unsigned long mask)
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{
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return count_masked_bytes(mask);
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}
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/* Return nonzero if it has a zero */
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static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
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{
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unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
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*bits = mask;
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return mask;
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}
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static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
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{
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return bits;
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}
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/* The mask we created is directly usable as a bytemask */
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#define zero_bytemask(mask) (mask)
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#endif /* CONFIG_64BIT */
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#endif /* __BIG_ENDIAN__ */
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/*
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* We use load_unaligned_zero() in a selftest, which builds a userspace
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* program. Some linker scripts seem to discard the .fixup section, so allow
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* the test code to use a different section name.
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*/
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#ifndef FIXUP_SECTION
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#define FIXUP_SECTION ".fixup"
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#endif
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static inline unsigned long load_unaligned_zeropad(const void *addr)
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{
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unsigned long ret, offset, tmp;
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asm(
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"1: " PPC_LL "%[ret], 0(%[addr])\n"
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"2:\n"
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".section " FIXUP_SECTION ",\"ax\"\n"
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"3: "
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#ifdef __powerpc64__
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"clrrdi %[tmp], %[addr], 3\n\t"
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"clrlsldi %[offset], %[addr], 61, 3\n\t"
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"ld %[ret], 0(%[tmp])\n\t"
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#ifdef __BIG_ENDIAN__
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"sld %[ret], %[ret], %[offset]\n\t"
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#else
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"srd %[ret], %[ret], %[offset]\n\t"
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#endif
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#else
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"clrrwi %[tmp], %[addr], 2\n\t"
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"clrlslwi %[offset], %[addr], 30, 3\n\t"
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"lwz %[ret], 0(%[tmp])\n\t"
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#ifdef __BIG_ENDIAN__
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"slw %[ret], %[ret], %[offset]\n\t"
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#else
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"srw %[ret], %[ret], %[offset]\n\t"
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#endif
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#endif
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"b 2b\n"
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".previous\n"
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EX_TABLE(1b, 3b)
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: [tmp] "=&b" (tmp), [offset] "=&r" (offset), [ret] "=&r" (ret)
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: [addr] "b" (addr), "m" (*(unsigned long *)addr));
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return ret;
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}
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#undef FIXUP_SECTION
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#endif /* _ASM_WORD_AT_A_TIME_H */
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