[PATCH 23/30] cpumask: Implement cpumask_{first,next}_{not,}andnot

[Mathieu Desnoyers <mathieu.desnoyers@efficios.com>]

Allow finding the first or next bit within two input cpumasks which is
either:

- both zero and zero,
- respectively one and zero.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 include/linux/cpumask.h | 60 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index c2aa0aa26b45..271bccc0a6d7 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -153,6 +153,32 @@ unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask
 	return find_first_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits);
 }
 
+/**
+ * cpumask_first_andnot - return the first cpu from *srcp1 & ~*srcp2
+ * @src1p: the first input
+ * @src2p: the second input
+ *
+ * Returns >= nr_cpu_ids if no cpus match in both.
+ */
+static inline
+unsigned int cpumask_first_andnot(const struct cpumask *srcp1, const struct cpumask *srcp2)
+{
+	return find_first_andnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits);
+}
+
+/**
+ * cpumask_first_notandnot - return the first cpu from ~*srcp1 & ~*srcp2
+ * @src1p: the first input
+ * @src2p: the second input
+ *
+ * Returns >= nr_cpu_ids if no cpus match in both.
+ */
+static inline
+unsigned int cpumask_first_notandnot(const struct cpumask *srcp1, const struct cpumask *srcp2)
+{
+	return find_first_notandnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits);
+}
+
 /**
  * cpumask_last - get the last CPU in a cpumask
  * @srcp:	- the cpumask pointer
@@ -195,6 +221,40 @@ static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 	return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 }
 
+/**
+ * cpumask_next_andnot - return the next cpu from *srcp1 & ~*srcp2
+ * @n: the cpu prior to the place to search (ie. return will be > @n)
+ * @src1p: the first input
+ * @src2p: the second input
+ *
+ * Returns >= nr_cpu_ids if no cpus match in both.
+ */
+static inline
+unsigned int cpumask_next_andnot(int n, const struct cpumask *srcp1, const struct cpumask *srcp2)
+{
+	/* -1 is a legal arg here. */
+	if (n != -1)
+		cpumask_check(n);
+	return find_next_andnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits, n+1);
+}
+
+/**
+ * cpumask_next_notandnot - return the next cpu from ~*srcp1 & ~*srcp2
+ * @n: the cpu prior to the place to search (ie. return will be > @n)
+ * @src1p: the first input
+ * @src2p: the second input
+ *
+ * Returns >= nr_cpu_ids if no cpus match in both.
+ */
+static inline
+unsigned int cpumask_next_notandnot(int n, const struct cpumask *srcp1, const struct cpumask *srcp2)
+{
+	/* -1 is a legal arg here. */
+	if (n != -1)
+		cpumask_check(n);
+	return find_next_notandnot_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits, n+1);
+}
+
 #if NR_CPUS == 1
 /* Uniprocessor: there is only one valid CPU */
 static inline unsigned int cpumask_local_spread(unsigned int i, int node)
-- 
2.25.1