1 files changed, 293 insertions, 0 deletions
diff --git a/tools/power/cpupower/utils/helpers/bitmask.c b/tools/power/cpupower/utils/helpers/bitmask.c
new file mode 100644
index 000000000..649d87cb8
--- /dev/null
+++ b/tools/power/cpupower/utils/helpers/bitmask.c
@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <helpers/bitmask.h>
+
+/* How many bits in an unsigned long */
+#define bitsperlong (8 * sizeof(unsigned long))
+
+/* howmany(a,b) : how many elements of size b needed to hold all of a */
+#define howmany(x, y) (((x)+((y)-1))/(y))
+
+/* How many longs in mask of n bits */
+#define longsperbits(n) howmany(n, bitsperlong)
+
+#define max(a, b) ((a) > (b) ? (a) : (b))
+
+/*
+ * Allocate and free `struct bitmask *`
+ */
+
+/* Allocate a new `struct bitmask` with a size of n bits */
+struct bitmask *bitmask_alloc(unsigned int n)
+{
+	struct bitmask *bmp;
+
+	bmp = malloc(sizeof(*bmp));
+	if (!bmp)
+		return 0;
+	bmp->size = n;
+	bmp->maskp = calloc(longsperbits(n), sizeof(unsigned long));
+	if (!bmp->maskp) {
+		free(bmp);
+		return 0;
+	}
+	return bmp;
+}
+
+/* Free `struct bitmask` */
+void bitmask_free(struct bitmask *bmp)
+{
+	if (!bmp)
+		return;
+	free(bmp->maskp);
+	bmp->maskp = (unsigned long *)0xdeadcdef;  /* double free tripwire */
+	free(bmp);
+}
+
+/*
+ * The routines _getbit() and _setbit() are the only
+ * routines that actually understand the layout of bmp->maskp[].
+ *
+ * On little endian architectures, this could simply be an array of
+ * bytes.  But the kernel layout of bitmasks _is_ visible to userspace
+ * via the sched_(set/get)affinity calls in Linux 2.6, and on big
+ * endian architectures, it is painfully obvious that this is an
+ * array of unsigned longs.
+ */
+
+/* Return the value (0 or 1) of bit n in bitmask bmp */
+static unsigned int _getbit(const struct bitmask *bmp, unsigned int n)
+{
+	if (n < bmp->size)
+		return (bmp->maskp[n/bitsperlong] >> (n % bitsperlong)) & 1;
+	else
+		return 0;
+}
+
+/* Set bit n in bitmask bmp to value v (0 or 1) */
+static void _setbit(struct bitmask *bmp, unsigned int n, unsigned int v)
+{
+	if (n < bmp->size) {
+		if (v)
+			bmp->maskp[n/bitsperlong] |= 1UL << (n % bitsperlong);
+		else
+			bmp->maskp[n/bitsperlong] &=
+				~(1UL << (n % bitsperlong));
+	}
+}
+
+/*
+ * When parsing bitmask lists, only allow numbers, separated by one
+ * of the allowed next characters.
+ *
+ * The parameter 'sret' is the return from a sscanf "%u%c".  It is
+ * -1 if the sscanf input string was empty.  It is 0 if the first
+ * character in the sscanf input string was not a decimal number.
+ * It is 1 if the unsigned number matching the "%u" was the end of the
+ * input string.  It is 2 if one or more additional characters followed
+ * the matched unsigned number.  If it is 2, then 'nextc' is the first
+ * character following the number.  The parameter 'ok_next_chars'
+ * is the nul-terminated list of allowed next characters.
+ *
+ * The mask term just scanned was ok if and only if either the numbers
+ * matching the %u were all of the input or if the next character in
+ * the input past the numbers was one of the allowed next characters.
+ */
+static int scan_was_ok(int sret, char nextc, const char *ok_next_chars)
+{
+	return sret == 1 ||
+		(sret == 2 && strchr(ok_next_chars, nextc) != NULL);
+}
+
+static const char *nexttoken(const char *q,  int sep)
+{
+	if (q)
+		q = strchr(q, sep);
+	if (q)
+		q++;
+	return q;
+}
+
+/* Set a single bit i in bitmask */
+struct bitmask *bitmask_setbit(struct bitmask *bmp, unsigned int i)
+{
+	_setbit(bmp, i, 1);
+	return bmp;
+}
+
+/* Set all bits in bitmask: bmp = ~0 */
+struct bitmask *bitmask_setall(struct bitmask *bmp)
+{
+	unsigned int i;
+	for (i = 0; i < bmp->size; i++)
+		_setbit(bmp, i, 1);
+	return bmp;
+}
+
+/* Clear all bits in bitmask: bmp = 0 */
+struct bitmask *bitmask_clearall(struct bitmask *bmp)
+{
+	unsigned int i;
+	for (i = 0; i < bmp->size; i++)
+		_setbit(bmp, i, 0);
+	return bmp;
+}
+
+/* True if all bits are clear */
+int bitmask_isallclear(const struct bitmask *bmp)
+{
+	unsigned int i;
+	for (i = 0; i < bmp->size; i++)
+		if (_getbit(bmp, i))
+			return 0;
+	return 1;
+}
+
+/* True if specified bit i is set */
+int bitmask_isbitset(const struct bitmask *bmp, unsigned int i)
+{
+	return _getbit(bmp, i);
+}
+
+/* Number of lowest set bit (min) */
+unsigned int bitmask_first(const struct bitmask *bmp)
+{
+	return bitmask_next(bmp, 0);
+}
+
+/* Number of highest set bit (max) */
+unsigned int bitmask_last(const struct bitmask *bmp)
+{
+	unsigned int i;
+	unsigned int m = bmp->size;
+	for (i = 0; i < bmp->size; i++)
+		if (_getbit(bmp, i))
+			m = i;
+	return m;
+}
+
+/* Number of next set bit at or above given bit i */
+unsigned int bitmask_next(const struct bitmask *bmp, unsigned int i)
+{
+	unsigned int n;
+	for (n = i; n < bmp->size; n++)
+		if (_getbit(bmp, n))
+			break;
+	return n;
+}
+
+/*
+ * Parses a comma-separated list of numbers and ranges of numbers,
+ * with optional ':%u' strides modifying ranges, into provided bitmask.
+ * Some examples of input lists and their equivalent simple list:
+ *	Input		Equivalent to
+ *	0-3		0,1,2,3
+ *	0-7:2		0,2,4,6
+ *	1,3,5-7		1,3,5,6,7
+ *	0-3:2,8-15:4	0,2,8,12
+ */
+int bitmask_parselist(const char *buf, struct bitmask *bmp)
+{
+	const char *p, *q;
+
+	bitmask_clearall(bmp);
+
+	q = buf;
+	while (p = q, q = nexttoken(q, ','), p) {
+		unsigned int a;		/* begin of range */
+		unsigned int b;		/* end of range */
+		unsigned int s;		/* stride */
+		const char *c1, *c2;	/* next tokens after '-' or ',' */
+		char nextc;		/* char after sscanf %u match */
+		int sret;		/* sscanf return (number of matches) */
+
+		sret = sscanf(p, "%u%c", &a, &nextc);
+		if (!scan_was_ok(sret, nextc, ",-"))
+			goto err;
+		b = a;
+		s = 1;
+		c1 = nexttoken(p, '-');
+		c2 = nexttoken(p, ',');
+		if (c1 != NULL && (c2 == NULL || c1 < c2)) {
+			sret = sscanf(c1, "%u%c", &b, &nextc);
+			if (!scan_was_ok(sret, nextc, ",:"))
+				goto err;
+			c1 = nexttoken(c1, ':');
+			if (c1 != NULL && (c2 == NULL || c1 < c2)) {
+				sret = sscanf(c1, "%u%c", &s, &nextc);
+				if (!scan_was_ok(sret, nextc, ","))
+					goto err;
+			}
+		}
+		if (!(a <= b))
+			goto err;
+		if (b >= bmp->size)
+			goto err;
+		while (a <= b) {
+			_setbit(bmp, a, 1);
+			a += s;
+		}
+	}
+	return 0;
+err:
+	bitmask_clearall(bmp);
+	return -1;
+}
+
+/*
+ * emit(buf, buflen, rbot, rtop, len)
+ *
+ * Helper routine for bitmask_displaylist().  Write decimal number
+ * or range to buf+len, suppressing output past buf+buflen, with optional
+ * comma-prefix.  Return len of what would be written to buf, if it
+ * all fit.
+ */
+
+static inline int emit(char *buf, int buflen, int rbot, int rtop, int len)
+{
+	if (len > 0)
+		len += snprintf(buf + len, max(buflen - len, 0), ",");
+	if (rbot == rtop)
+		len += snprintf(buf + len, max(buflen - len, 0), "%d", rbot);
+	else
+		len += snprintf(buf + len, max(buflen - len, 0), "%d-%d",
+				rbot, rtop);
+	return len;
+}
+
+/*
+ * Write decimal list representation of bmp to buf.
+ *
+ * Output format is a comma-separated list of decimal numbers and
+ * ranges.  Consecutively set bits are shown as two hyphen-separated
+ * decimal numbers, the smallest and largest bit numbers set in
+ * the range.  Output format is compatible with the format
+ * accepted as input by bitmap_parselist().
+ *
+ * The return value is the number of characters which would be
+ * generated for the given input, excluding the trailing '\0', as
+ * per ISO C99.
+ */
+
+int bitmask_displaylist(char *buf, int buflen, const struct bitmask *bmp)
+{
+	int len = 0;
+	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
+	unsigned int cur, rbot, rtop;
+
+	if (buflen > 0)
+		*buf = 0;
+	rbot = cur = bitmask_first(bmp);
+	while (cur < bmp->size) {
+		rtop = cur;
+		cur = bitmask_next(bmp, cur+1);
+		if (cur >= bmp->size || cur > rtop + 1) {
+			len = emit(buf, buflen, rbot, rtop, len);
+			rbot = cur;
+		}
+	}
+	return len;
+}