diff options
| -rw-r--r-- | arch/s390/include/asm/bitops.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/s390/include/asm/bitops.h b/arch/s390/include/asm/bitops.h index 6f573890fb28..15422933c60b 100644 --- a/arch/s390/include/asm/bitops.h +++ b/arch/s390/include/asm/bitops.h @@ -640,6 +640,87 @@ static inline unsigned long find_first_bit(const unsigned long * addr, } #define find_first_bit find_first_bit +/* + * Big endian variant whichs starts bit counting from left using + * the flogr (find leftmost one) instruction. + */ +static inline unsigned long __flo_word(unsigned long nr, unsigned long val) +{ + register unsigned long bit asm("2") = val; + register unsigned long out asm("3"); + + asm volatile ( + " .insn rre,0xb9830000,%[bit],%[bit]\n" + : [bit] "+d" (bit), [out] "=d" (out) : : "cc"); + return nr + bit; +} + +/* + * 64 bit special left bitops format: + * order in memory: + * 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f + * 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f + * 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f + * 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f + * after that follows the next long with bit numbers + * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f + * 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f + * 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f + * 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f + * The reason for this bit ordering is the fact that + * the hardware sets bits in a bitmap starting at bit 0 + * and we don't want to scan the bitmap from the 'wrong + * end'. + */ +static inline unsigned long find_first_bit_left(const unsigned long *addr, + unsigned long size) +{ + unsigned long bytes, bits; + + if (!size) + return 0; + bytes = __ffs_word_loop(addr, size); + bits = __flo_word(bytes * 8, __load_ulong_be(addr, bytes)); + return (bits < size) ? bits : size; +} + +static inline int find_next_bit_left(const unsigned long *addr, + unsigned long size, + unsigned long offset) +{ + const unsigned long *p; + unsigned long bit, set; + + if (offset >= size) + return size; + bit = offset & (__BITOPS_WORDSIZE - 1); + offset -= bit; + size -= offset; + p = addr + offset / __BITOPS_WORDSIZE; + if (bit) { + set = __flo_word(0, *p & (~0UL << bit)); + if (set >= size) + return size + offset; + if (set < __BITOPS_WORDSIZE) + return set + offset; + offset += __BITOPS_WORDSIZE; + size -= __BITOPS_WORDSIZE; + p++; + } + return offset + find_first_bit_left(p, size); +} + +#define for_each_set_bit_left(bit, addr, size) \ + for ((bit) = find_first_bit_left((addr), (size)); \ + (bit) < (size); \ + (bit) = find_next_bit_left((addr), (size), (bit) + 1)) + +/* same as for_each_set_bit() but use bit as value to start with */ +#define for_each_set_bit_left_cont(bit, addr, size) \ + for ((bit) = find_next_bit_left((addr), (size), (bit)); \ + (bit) < (size); \ + (bit) = find_next_bit_left((addr), (size), (bit) + 1)) + /** * find_next_zero_bit - find the first zero bit in a memory region * @addr: The address to base the search on |