Commit 30544ed5 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Linus Torvalds
Browse files

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: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: default avatarLinus 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 780ff33b

include/linux/bitmap.h

+16 −0
Original line number Diff line number Diff line
@@ -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)

{

lib/bitmap.c

+12 −0
Original line number Diff line number Diff line
@@ -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)

{

lib/test_bitmap.c

+38 −0
Original line number Diff line number Diff line
@@ -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();

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