diff options
| -rw-r--r-- | include/linux/bitmap.h | 16 | ||||
| -rw-r--r-- | lib/bitmap.c | 12 | ||||
| -rw-r--r-- | lib/test_bitmap.c | 38 |
3 files changed, 66 insertions, 0 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 9f046609e809..ff335b22f23c 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -53,6 +53,7 @@ * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n + * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask) * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit) * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap @@ -140,6 +141,9 @@ extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); +extern void __bitmap_replace(unsigned long *dst, + const unsigned long *old, const unsigned long *new, + const unsigned long *mask, unsigned int nbits); extern int __bitmap_intersects(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int nbits); extern int __bitmap_subset(const unsigned long *bitmap1, @@ -434,6 +438,18 @@ static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *sr __bitmap_shift_left(dst, src, shift, nbits); } +static inline void bitmap_replace(unsigned long *dst, + const unsigned long *old, + const unsigned long *new, + const unsigned long *mask, + unsigned int nbits) +{ + if (small_const_nbits(nbits)) + *dst = (*old & ~(*mask)) | (*new & *mask); + else + __bitmap_replace(dst, old, new, mask, nbits); +} + static inline int bitmap_parse(const char *buf, unsigned int buflen, unsigned long *maskp, int nmaskbits) { diff --git a/lib/bitmap.c b/lib/bitmap.c index f9e834841e94..4250519d7d1c 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -222,6 +222,18 @@ int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, } EXPORT_SYMBOL(__bitmap_andnot); +void __bitmap_replace(unsigned long *dst, + const unsigned long *old, const unsigned long *new, + const unsigned long *mask, unsigned int nbits) +{ + unsigned int k; + unsigned int nr = BITS_TO_LONGS(nbits); + + for (k = 0; k < nr; k++) + dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]); +} +EXPORT_SYMBOL(__bitmap_replace); + int __bitmap_intersects(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index 4544847cf81e..e14a15ac250b 100644 --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -42,6 +42,19 @@ static const unsigned long exp2[] __initconst = { BITMAP_FROM_U64(0xffffffff77777777ULL), }; +/* Fibonacci sequence */ +static const unsigned long exp2_to_exp3_mask[] __initconst = { + BITMAP_FROM_U64(0x008000020020212eULL), +}; +/* exp3_0_1 = (exp2[0] & ~exp2_to_exp3_mask) | (exp2[1] & exp2_to_exp3_mask) */ +static const unsigned long exp3_0_1[] __initconst = { + BITMAP_FROM_U64(0x33b3333311313137ULL), +}; +/* exp3_1_0 = (exp2[1] & ~exp2_to_exp3_mask) | (exp2[0] & exp2_to_exp3_mask) */ +static const unsigned long exp3_1_0[] __initconst = { + BITMAP_FROM_U64(0xff7fffff77575751ULL), +}; + static bool __init __check_eq_uint(const char *srcfile, unsigned int line, const unsigned int exp_uint, unsigned int x) @@ -257,6 +270,30 @@ static void __init test_copy(void) expect_eq_pbl("0-108,128-1023", bmap2, 1024); } +#define EXP2_IN_BITS (sizeof(exp2) * 8) + +static void __init test_replace(void) +{ + unsigned int nbits = 64; + DECLARE_BITMAP(bmap, 1024); + + bitmap_zero(bmap, 1024); + bitmap_replace(bmap, &exp2[0], &exp2[1], exp2_to_exp3_mask, nbits); + expect_eq_bitmap(bmap, exp3_0_1, nbits); + + bitmap_zero(bmap, 1024); + bitmap_replace(bmap, &exp2[1], &exp2[0], exp2_to_exp3_mask, nbits); + expect_eq_bitmap(bmap, exp3_1_0, nbits); + + bitmap_fill(bmap, 1024); + bitmap_replace(bmap, &exp2[0], &exp2[1], exp2_to_exp3_mask, nbits); + expect_eq_bitmap(bmap, exp3_0_1, nbits); + + bitmap_fill(bmap, 1024); + bitmap_replace(bmap, &exp2[1], &exp2[0], exp2_to_exp3_mask, nbits); + expect_eq_bitmap(bmap, exp3_1_0, nbits); +} + #define PARSE_TIME 0x1 struct test_bitmap_parselist{ @@ -476,6 +513,7 @@ static void __init selftest(void) test_zero_clear(); test_fill_set(); test_copy(); + test_replace(); test_bitmap_arr32(); test_bitmap_parselist(); test_bitmap_parselist_user(); |