#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> #include <asm/ppc_asm.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" EX_TABLE(1b, 3b) : [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 */