firewire: core: ensure some userspace API constants match corresponding kernel API...

The FW_ISO_ constants of the in-kernel API of firewire-core and
FW_CDEV_ISO_ constants of the userspace API of firewire-core have
nothing to do with each other --- except that the core-cdev.c
implementation relies on them having the same values.

Hence put some compile-time assertions into core-cdev.c.  It's lame but
I prefer it over including the userspace API header into the kernelspace
API header and defining kernelspace API constants from userspace API
constants.  Nor do I want to expose the kernelspace constants in one of
the two firewire headers that are exported to userland since this only
concerns the core-cdev.c implementation.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index f7559bf..7a690c4 100644 (file)
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -18,6 +18,7 @@
  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include <linux/bug.h>
 #include <linux/compat.h>
 #include <linux/delay.h>
 #include <linux/device.h>
@@ -909,6 +910,9 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)
        struct fw_cdev_create_iso_context *a = &arg->create_iso_context;
        struct fw_iso_context *context;
 
+       BUILD_BUG_ON(FW_CDEV_ISO_CONTEXT_TRANSMIT != FW_ISO_CONTEXT_TRANSMIT ||
+                    FW_CDEV_ISO_CONTEXT_RECEIVE  != FW_ISO_CONTEXT_RECEIVE);
+
        if (a->channel > 63)
                return -EINVAL;
 
@@ -1060,6 +1064,13 @@ static int ioctl_start_iso(struct client *client, union ioctl_arg *arg)
 {
        struct fw_cdev_start_iso *a = &arg->start_iso;
 
+       BUILD_BUG_ON(
+           FW_CDEV_ISO_CONTEXT_MATCH_TAG0 != FW_ISO_CONTEXT_MATCH_TAG0 ||
+           FW_CDEV_ISO_CONTEXT_MATCH_TAG1 != FW_ISO_CONTEXT_MATCH_TAG1 ||
+           FW_CDEV_ISO_CONTEXT_MATCH_TAG2 != FW_ISO_CONTEXT_MATCH_TAG2 ||
+           FW_CDEV_ISO_CONTEXT_MATCH_TAG3 != FW_ISO_CONTEXT_MATCH_TAG3 ||
+           FW_CDEV_ISO_CONTEXT_MATCH_ALL_TAGS != FW_ISO_CONTEXT_MATCH_ALL_TAGS);
+
        if (client->iso_context == NULL || a->handle != 0)
                return -EINVAL;