target: Allow control CDBs with data > 1 page

We need to handle >1 page control cdbs, so extend the code to do a vmap
if bigger than 1 page. It seems like kmap() is still preferable if just
a page, fewer TLB shootdowns(?), so keep using that when possible.

Rename function pair for their new scope.

Signed-off-by: Andy Grover <agrover@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 3 insertions, 2 deletions

diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 4866499bdee..e5e6ff98f0f 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -59,7 +59,7 @@ int	transport_set_vpd_ident_type(struct t10_vpd *, unsigned char *);
 int     transport_set_vpd_ident(struct t10_vpd *, unsigned char *);
 
 /* core helpers also used by command snooping in pscsi */
-void    *transport_kmap_first_data_page(struct se_cmd *);
-void    transport_kunmap_first_data_page(struct se_cmd *);
+void    *transport_kmap_data_sg(struct se_cmd *);
+void    transport_kunmap_data_sg(struct se_cmd *);
 
 #endif /* TARGET_CORE_BACKEND_H */
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index daf532bc721..dc4e345a016 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -582,6 +582,7 @@ struct se_cmd {
 
         struct scatterlist      *t_data_sg;
         unsigned int            t_data_nents;
+        void                    *t_data_vmap;
         struct scatterlist      *t_bidi_data_sg;
         unsigned int            t_bidi_data_nents;