cpumask: introduce new API, without changing anything, v3

Impact: cleanup

Clean up based on feedback from Andrew Morton and others:

 - change to inline functions instead of macros
 - add __init to bootmem method
 - add a missing debug check

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 54 insertions, 7 deletions

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 31caa1bc620a..21e1dd43e52a 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -564,12 +564,36 @@ static inline unsigned int cpumask_check(unsigned int cpu)
 }
 
 #if NR_CPUS == 1
-/* Uniprocesor. */
-#define cpumask_first(src)              ({ (void)(src); 0; })
-#define cpumask_next(n, src)            ({ (void)(src); 1; })
-#define cpumask_next_zero(n, src)       ({ (void)(src); 1; })
-#define cpumask_next_and(n, srcp, andp) ({ (void)(srcp), (void)(andp); 1; })
-#define cpumask_any_but(mask, cpu)      ({ (void)(mask); (void)(cpu); 0; })
+/* Uniprocessor.  Assume all masks are "1". */
+static inline unsigned int cpumask_first(const struct cpumask *srcp)
+{
+        return 0;
+}
+
+/* Valid inputs for n are -1 and 0. */
+static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
+{
+        return n+1;
+}
+
+static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
+{
+        return n+1;
+}
+
+static inline unsigned int cpumask_next_and(int n,
+                                            const struct cpumask *srcp,
+                                            const struct cpumask *andp)
+{
+        return n+1;
+}
+
+/* cpu must be a valid cpu, ie 0, so there's no other choice. */
+static inline unsigned int cpumask_any_but(const struct cpumask *mask,
+                                           unsigned int cpu)
+{
+        return 1;
+}
 
 #define for_each_cpu(cpu, mask)                 \
         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
@@ -620,10 +644,32 @@ static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
 
+/**
+ * for_each_cpu - iterate over every cpu in a mask
+ * @cpu: the (optionally unsigned) integer iterator
+ * @mask: the cpumask pointer
+ *
+ * After the loop, cpu is >= nr_cpu_ids.
+ */
 #define for_each_cpu(cpu, mask)                         \
         for ((cpu) = -1;                                \
                 (cpu) = cpumask_next((cpu), (mask)),    \
                 (cpu) < nr_cpu_ids;)
+
+/**
+ * for_each_cpu_and - iterate over every cpu in both masks
+ * @cpu: the (optionally unsigned) integer iterator
+ * @mask: the first cpumask pointer
+ * @and: the second cpumask pointer
+ *
+ * This saves a temporary CPU mask in many places.  It is equivalent to:
+ *      struct cpumask tmp;
+ *      cpumask_and(&tmp, &mask, &and);
+ *      for_each_cpu(cpu, &tmp)
+ *              ...
+ *
+ * After the loop, cpu is >= nr_cpu_ids.
+ */
 #define for_each_cpu_and(cpu, mask, and)                                \
         for ((cpu) = -1;                                                \
                 (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
diff --git a/lib/cpumask.c b/lib/cpumask.c
index 2ebc3a9a7465..8d03f22c6ced 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -67,6 +67,7 @@ int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
 {
         unsigned int i;
 
+        cpumask_check(cpu);
         for_each_cpu(i, mask)
                 if (i != cpu)
                         break;
@@ -108,7 +109,7 @@ void free_cpumask_var(cpumask_var_t mask)
 }
 EXPORT_SYMBOL(free_cpumask_var);
 
-void free_bootmem_cpumask_var(cpumask_var_t mask)
+void __init free_bootmem_cpumask_var(cpumask_var_t mask)
 {
         free_bootmem((unsigned long)mask, cpumask_size());
 }