padata: Check for valid padata instance on start

This patch introduces the PADATA_INVALID flag which is
checked on padata start. This will be used to mark a padata
instance as invalid, if the padata cpumask does not intersect
with the active cpumask. we change padata_start to return an
error if the PADATA_INVALID is set. Also we adapt the only
padata user, pcrypt to this change.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/padata.h b/include/linux/padata.h
index 8d8406246eef..e4c17f9b7c9e 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -126,6 +126,7 @@ struct padata_instance {
         u8                      flags;
 #define PADATA_INIT             1
 #define PADATA_RESET            2
+#define PADATA_INVALID          4
 };
 
 extern struct padata_instance *padata_alloc(const struct cpumask *cpumask,
@@ -138,6 +139,6 @@ extern int padata_set_cpumask(struct padata_instance *pinst,
                               cpumask_var_t cpumask);
 extern int padata_add_cpu(struct padata_instance *pinst, int cpu);
 extern int padata_remove_cpu(struct padata_instance *pinst, int cpu);
-extern void padata_start(struct padata_instance *pinst);
+extern int padata_start(struct padata_instance *pinst);
 extern void padata_stop(struct padata_instance *pinst);
 #endif