kernel: add bitmap datatype

ds/bitmap.c

@@ -0,0 +1,167 @@
+#include <socks/libc/string.h>
+#include <socks/bitmap.h>
+
+void bitmap_zero(unsigned long *map, unsigned long nbits)
+{
+	unsigned long words = BITMAP_WORDS(nbits);
+	memset(map, 0x00, words * sizeof *map);
+}
+
+void bitmap_fill(unsigned long *map, unsigned long nbits)
+{
+	unsigned long words = BITMAP_WORDS(nbits);
+	memset(map, 0xFF, words * sizeof *map);
+}
+
+void bitmap_set(unsigned long *map, unsigned long bit)
+{
+	unsigned long index = bit / BITS_PER_WORD;
+	unsigned long offset = (BITS_PER_WORD - bit - 1) & (BITS_PER_WORD - 1);
+	unsigned long mask = 1ul << offset;
+	
+	map[index] |= mask;
+}
+
+void bitmap_clear(unsigned long *map, unsigned long bit)
+{
+	unsigned long index = bit / BITS_PER_WORD;
+	unsigned long offset = bit & (BITS_PER_WORD - 1);
+	unsigned long mask = 1ul << offset;
+	
+	map[index] &= ~mask;
+}
+
+bool bitmap_check(unsigned long *map, unsigned long bit)
+{
+	unsigned long index = bit / BITS_PER_WORD;
+	unsigned long offset = bit & (BITS_PER_WORD - 1);
+	unsigned long mask = 1ul << offset;
+	
+	return (map[index] & mask) != 0 ? true : false;
+	
+}
+
+unsigned int bitmap_count_set(unsigned long *map, unsigned long nbits)
+{
+	unsigned long words = BITMAP_WORDS(nbits);
+	unsigned int set_bits = 0;
+
+	for (unsigned long i = 0; i < words; i++) {
+		set_bits += __builtin_popcountl(map[i]);
+	}
+
+	if (set_bits > nbits) {
+		set_bits = nbits;
+	}
+
+	return set_bits;
+}
+
+unsigned int bitmap_count_clear(unsigned long *map, unsigned long nbits)
+{
+	unsigned long words = BITMAP_WORDS(nbits);
+	unsigned int clear_bits = 0;
+
+	for (unsigned long i = 0; i < words; i++) {
+		clear_bits += __builtin_popcountl(~map[i]);
+	}
+
+	if (clear_bits > nbits) {
+		clear_bits = nbits;
+	}
+
+	return clear_bits;
+}
+
+unsigned int bitmap_highest_set(unsigned long *map, unsigned long nbits)
+{
+	unsigned long words = BITMAP_WORDS(nbits);
+	unsigned long bit_index = 0;
+	unsigned long last_word = 0;
+
+	unsigned long i;
+	for (i = 0; i < words; i++) {
+		if (map[i] != 0x00) {
+			last_word = map[i];
+			bit_index = i * BITS_PER_WORD;
+		}
+	}
+
+	if (last_word == 0x00) {
+		return (unsigned int)-1;
+	}
+
+	return bit_index + (BITS_PER_WORD - __builtin_ctzl(last_word) - 1);
+}
+
+unsigned int bitmap_highest_clear(unsigned long *map, unsigned long nbits)
+{
+	unsigned long words = BITMAP_WORDS(nbits);
+	unsigned long bit_index = 0;
+	unsigned long last_word = ~(unsigned long)0;
+
+	for (unsigned long i = 0; i < words; i++) {
+		if (map[i] != (~(unsigned long)0)) {
+			last_word = map[i];
+			bit_index = i * BITS_PER_WORD;
+		}
+	}
+
+	if (last_word == ~(unsigned long)0) {
+		return (unsigned int)-1;
+	}
+
+	if (last_word == 0) {
+		return bit_index + BITS_PER_WORD - 1;
+	}
+
+	return bit_index + (BITS_PER_WORD - __builtin_ctzl(~last_word)) - 1;
+}
+
+unsigned int bitmap_lowest_set(unsigned long *map, unsigned long nbits)
+{
+	unsigned long words = BITMAP_WORDS(nbits);
+	unsigned long bit_index = 0;
+	unsigned long last_word = 0;
+
+	unsigned long i;
+	for (i = 0; i < words; i++) {
+		if (map[i] != 0x00) {
+			last_word = map[i];
+			bit_index = i * BITS_PER_WORD;
+			break;
+		}
+	}
+
+	if (last_word == 0x00) {
+		return (unsigned int)-1;
+	}
+
+	return bit_index + __builtin_clzl(last_word);
+}
+
+unsigned int bitmap_lowest_clear(unsigned long *map, unsigned long nbits)
+{
+	unsigned long words = BITMAP_WORDS(nbits);
+	unsigned long bit_index = 0;
+	unsigned long last_word = 0;
+
+	unsigned long i;
+	for (i = 0; i < words; i++) {
+		if (map[i] != (~(unsigned long)0)) {
+			last_word = map[i];
+			bit_index = i * BITS_PER_WORD;
+			break;
+		}
+	}
+
+	if (last_word == 0) {
+		return bit_index;
+	}
+
+	if (last_word == (~(unsigned long)0)) {
+		return (unsigned int)-1;
+	}
+
+	return bit_index + __builtin_clzl(~last_word);
+}

include/socks/bitmap.h

@@ -0,0 +1,26 @@
+#ifndef SOCKS_BITMAP_H_
+#define SOCKS_BITMAP_H_
+
+#include <stdbool.h>
+
+#define BITS_PER_WORD (8 * sizeof(unsigned long))
+#define __DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
+#define BITMAP_WORDS(nbits) __DIV_ROUND_UP(nbits, BITS_PER_WORD)
+
+#define DECLARE_BITMAP(name, nbits) unsigned long name[BITMAP_WORDS(nbits)]
+
+extern void bitmap_zero(unsigned long *map, unsigned long nbits);
+extern void bitmap_fill(unsigned long *map, unsigned long nbits);
+extern void bitmap_set(unsigned long *map, unsigned long bit);
+extern void bitmap_clear(unsigned long *map, unsigned long bit);
+extern bool bitmap_check(unsigned long *map, unsigned long bit);
+
+extern unsigned int bitmap_count_set(unsigned long *map, unsigned long nbits);
+extern unsigned int bitmap_count_clear(unsigned long *map, unsigned long nbits);
+
+extern unsigned int bitmap_highest_set(unsigned long *map, unsigned long nbits);
+extern unsigned int bitmap_highest_clear(unsigned long *map, unsigned long nbits);
+extern unsigned int bitmap_lowest_set(unsigned long *map, unsigned long nbits);
+extern unsigned int bitmap_lowest_clear(unsigned long *map, unsigned long nbits);
+
+#endif