diff options
author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2019-12-05 03:53:26 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-05 06:44:14 +0300 |
commit | 30544ed5de431fe25d3793e4dd5a058d877c4d77 (patch) | |
tree | 4e61a782d8482dc987228ecddd854441f9bb6f68 /lib | |
parent | 780ff33b8bfac4f44fcc399a870d50ff2e74b33d (diff) | |
download | linux-30544ed5de431fe25d3793e4dd5a058d877c4d77.tar.xz |
lib/bitmap: introduce bitmap_replace() helper
In some drivers we want to have a single operation over bitmap which is
an equivalent to:
*dst = (*old & ~(*mask)) | (*new & *mask)
Introduce bitmap_replace() helper for this.
Link: http://lkml.kernel.org/r/20191022172922.61232-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/bitmap.c | 12 | ||||
-rw-r--r-- | lib/test_bitmap.c | 38 |
2 files changed, 50 insertions, 0 deletions
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(); |