atomic: Add atomic_set_bit_to() API

Several places in the code have constructions like this:

	if (bool_variable) {
		atomic_set_bit(flags, FLAG);
	} else {
		atomic_clear_bit(flags, FLAG);
	}

To reduce the amount of code for such situations, introduce a new
atomic_set_bit_to() helper which lets you condense the above five
lines to a single one:

	atomic_set_bit_to(flags, FLAG, bool_variable);

Signed-off-by: Johan Hedberg <[email protected]>

Author: Johan Hedberg

include/atomic.h

@@ -411,6 +411,29 @@ static inline void atomic_set_bit(atomic_t *target, int bit)
 	(void)atomic_or(ATOMIC_ELEM(target, bit), mask);
 }
 
+/**
+ * @brief Atomically set a bit to a given value.
+ *
+ * Atomically set bit number @a bit of @a target to value @a val.
+ * The target may be a single atomic variable or an array of them.
+ *
+ * @param target Address of atomic variable or array.
+ * @param bit Bit number (starting from 0).
+ * @param val true for 1, false for 0.
+ *
+ * @return N/A
+ */
+static inline void atomic_set_bit_to(atomic_t *target, int bit, bool val)
+{
+	atomic_val_t mask = ATOMIC_MASK(bit);
+
+	if (val) {
+		(void)atomic_or(ATOMIC_ELEM(target, bit), mask);
+	} else {
+		(void)atomic_and(ATOMIC_ELEM(target, bit), ~mask);
+	}
+}
+
 /**
  * @}
  */

tests/kernel/common/src/atomic.c

@@ -142,6 +142,21 @@ void test_atomic(void)
 		zassert_true(target == (orig | (1 << i)), "atomic_set_bit");
 	}
 
+	/* atomic_set_bit_to(&target, i, false) */
+	for (i = 0; i < 32; i++) {
+		orig = 0x0F0F0F0F;
+		target = orig;
+		atomic_set_bit_to(&target, i, false);
+		zassert_true(target == (orig & ~(1 << i)), "atomic_set_bit_to");
+	}
+
+	/* atomic_set_bit_to(&target, i, true) */
+	for (i = 0; i < 32; i++) {
+		orig = 0x0F0F0F0F;
+		target = orig;
+		atomic_set_bit_to(&target, i, true);
+		zassert_true(target == (orig | (1 << i)), "atomic_set_bit_to");
+	}
 }
 /**
  * @}