Commit 4fe49b3b authored by Yury Norov's avatar Yury Norov
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lib/bitmap: introduce for_each_set_bit_wrap() macro 



Add for_each_set_bit_wrap() macro and use it in for_each_cpu_wrap(). The
new macro is based on __for_each_wrap() iterator, which is simpler and
smaller than cpumask_next_wrap().

Signed-off-by: default avatarYury Norov <yury.norov@gmail.com>
parent 6cc18331

include/linux/cpumask.h

+2 −4
Original line number Diff line number Diff line
@@ -290,9 +290,7 @@ unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int sta 
 * After the loop, cpu is >= nr_cpu_ids.

 */

#define for_each_cpu_wrap(cpu, mask, start)				\

	for ((cpu) = cpumask_next_wrap((start)-1, (mask), (start), false);	\

	     (cpu) < nr_cpumask_bits;						\

	     (cpu) = cpumask_next_wrap((cpu), (mask), (start), true))

	for_each_set_bit_wrap(cpu, cpumask_bits(mask), nr_cpumask_bits, start)



/**

 * for_each_cpu_and - iterate over every cpu in both masks

include/linux/find.h

+39 −0
Original line number Diff line number Diff line
@@ -336,6 +336,32 @@ unsigned long find_next_bit_wrap(const unsigned long *addr, 
	return bit < offset ? bit : size;

}



/*

 * Helper for for_each_set_bit_wrap(). Make sure you're doing right thing

 * before using it alone.

 */

static inline

unsigned long __for_each_wrap(const unsigned long *bitmap, unsigned long size,

				 unsigned long start, unsigned long n)

{

	unsigned long bit;



	/* If not wrapped around */

	if (n > start) {

		/* and have a bit, just return it. */

		bit = find_next_bit(bitmap, size, n);

		if (bit < size)

			return bit;



		/* Otherwise, wrap around and ... */

		n = 0;

	}



	/* Search the other part. */

	bit = find_next_bit(bitmap, start, n);

	return bit < start ? bit : size;

}



/**

 * find_next_clump8 - find next 8-bit clump with set bits in a memory region

 * @clump: location to store copy of found clump
@@ -514,6 +540,19 @@ unsigned long find_next_bit_le(const void *addr, unsigned 
	     (b) = find_next_zero_bit((addr), (size), (e) + 1),	\

	     (e) = find_next_bit((addr), (size), (b) + 1))



/**

 * for_each_set_bit_wrap - iterate over all set bits starting from @start, and

 * wrapping around the end of bitmap.

 * @bit: offset for current iteration

 * @addr: bitmap address to base the search on

 * @size: bitmap size in number of bits

 * @start: Starting bit for bitmap traversing, wrapping around the bitmap end

 */

#define for_each_set_bit_wrap(bit, addr, size, start) \

	for ((bit) = find_next_bit_wrap((addr), (size), (start));		\

	     (bit) < (size);							\

	     (bit) = __for_each_wrap((addr), (size), (start), (bit) + 1))



/**

 * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits

 * @start: bit offset to start search and to store the current iteration offset