cpumask: Add helper cpumask_available()
With CONFIG_CPUMASK_OFFSTACK=y cpumask_var_t is a struct cpumask
pointer, otherwise a struct cpumask array with a single element.
Some code dealing with cpumasks needs to validate that a cpumask_var_t
is not a NULL pointer when CONFIG_CPUMASK_OFFSTACK=y. This is typically
done by performing the check always, regardless of the underlying type
of cpumask_var_t. This works in both cases, however clang raises a
warning like this when CONFIG_CPUMASK_OFFSTACK=n:
kernel/irq/manage.c:839:28: error: address of array
'desc->irq_common_data.affinity' will always evaluate to 'true'
[-Werror,-Wpointer-bool-conversion]
Add the inline helper cpumask_available() which only performs the
pointer check if CONFIG_CPUMASK_OFFSTACK=y.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Grant Grundler <grundler@chromium.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Michael Davidson <md@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20170412182030.83657-1-mka@chromium.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 96f1e88..1a67560 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -667,6 +667,11 @@
void free_cpumask_var(cpumask_var_t mask);
void free_bootmem_cpumask_var(cpumask_var_t mask);
+static inline bool cpumask_available(cpumask_var_t mask)
+{
+ return mask != NULL;
+}
+
#else
typedef struct cpumask cpumask_var_t[1];
@@ -708,6 +713,11 @@
static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
{
}
+
+static inline bool cpumask_available(cpumask_var_t mask)
+{
+ return true;
+}
#endif /* CONFIG_CPUMASK_OFFSTACK */
/* It's common to want to use cpu_all_mask in struct member initializers,