Add bit set/clear functions, differentiate bit mask macros

1 files changed, 25 insertions, 1 deletions

diff --git a/bits.h b/bits.h
index 8374527..82eb153 100644
--- a/bits.h
+++ b/bits.h
@@ -11,6 +11,30 @@
 #ifndef _BITS_H_
 #define _BITS_H_
 
-#define BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL << (n))-1))
+#define BIT_MASK_FILL(n)	(((n) == 64) ? ~0ULL : ((1ULL << (n))-1))
+#define BIT_MASK(n)		(1UL << ((n) % 32))
+#define BIT_UINT32(n)		((n) / 32)
+
+/**
+ * Sets a bit in memory.
+ */
+static inline void set_bit(unsigned int nr, uint32_t *addr)
+{
+	uint32_t mask = BIT_MASK(nr);
+	uint32_t *p = addr + BIT_UINT32(nr);
+
+	*p |= mask;
+}
+
+/**
+ * Clears a bit in memory.
+ */
+static inline void clear_bit(unsigned int nr, uint32_t *addr)
+{
+	uint32_t mask = BIT_MASK(nr);
+	uint32_t *p = addr + BIT_UINT32(nr);
+
+	*p &= ~mask;
+}
 
 #endif /* _BITS_H_ */