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>
This commit is contained in:
Andy Shevchenko
2019-12-04 16:53:26 -08:00
committed by Linus Torvalds
parent 780ff33b8b
commit 30544ed5de
3 changed files with 66 additions and 0 deletions

View File

@@ -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();