Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #include <linux/bug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #include <linux/bitmap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * memweight - count the total number of bits set in memory area
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * @ptr: pointer to the start of the area
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * @bytes: the size of the area
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) size_t memweight(const void *ptr, size_t bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 	size_t ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 	size_t longs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 	const unsigned char *bitmap = ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	for (; bytes > 0 && ((unsigned long)bitmap) % sizeof(long);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 			bytes--, bitmap++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 		ret += hweight8(*bitmap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	longs = bytes / sizeof(long);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	if (longs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 		BUG_ON(longs >= INT_MAX / BITS_PER_LONG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 		ret += bitmap_weight((unsigned long *)bitmap,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 				longs * BITS_PER_LONG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 		bytes -= longs * sizeof(long);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 		bitmap += longs * sizeof(long);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	 * The reason that this last loop is distinct from the preceding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	 * bitmap_weight() call is to compute 1-bits in the last region smaller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	 * than sizeof(long) properly on big-endian systems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	for (; bytes > 0; bytes--, bitmap++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 		ret += hweight8(*bitmap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) EXPORT_SYMBOL(memweight);