greybus: rename HOST_DEV_CPORT_ID_MAX

We limit the number of host-side CPorts to a fixed maximum (which
is less than the 4096 that UniPro allows).  This patch imposes a
similar limit on the CPort IDs defined by modules (signaling an
error if one too large is found in a manifest).

It seems reasonable to use the same value for both limits.  Change
the name of the constant that defines the host limit and use it for
both.  Update cport_id_valid() to enforce the maximum.

(Ultimately we should impose a limit like this; this change is being
made in preparation for supporting multiple connections over a
single CPort.)
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/connection.c

@@ -158,7 +158,7 @@ struct gb_connection *gb_connection_create(struct gb_bundle *bundle,
 	if (!connection)
 		return NULL;
 
-	retval = ida_simple_get(id_map, 0, HOST_DEV_CPORT_ID_MAX, GFP_KERNEL);
+	retval = ida_simple_get(id_map, 0, CPORT_ID_MAX, GFP_KERNEL);
 	if (retval < 0) {
 		kfree(connection);
 		return NULL;

drivers/staging/greybus/core.c

@@ -246,7 +246,7 @@ static int __init gb_init(void)
 	if (greybus_disabled())
 		return -ENODEV;
 
-	BUILD_BUG_ON(HOST_DEV_CPORT_ID_MAX >= (long)CPORT_ID_BAD);
+	BUILD_BUG_ON(CPORT_ID_MAX >= (long)CPORT_ID_BAD);
 
 	gb_debugfs_init();
 

drivers/staging/greybus/greybus.h

@@ -52,14 +52,14 @@
 	.serial_number	= (s),
 
 /* XXX I couldn't get my Kconfig file to be noticed for out-of-tree build */
-#ifndef CONFIG_HOST_DEV_CPORT_ID_MAX
-#define CONFIG_HOST_DEV_CPORT_ID_MAX 128
-#endif /* !CONFIG_HOST_DEV_CPORT_ID_MAX */
+#ifndef CONFIG_CPORT_ID_MAX
+#define CONFIG_CPORT_ID_MAX 128
+#endif /* !CONFIG_CPORT_ID_MAX */
 
 /* Maximum number of CPorts usable by a host device */
 /* XXX This should really be determined by the AP module manifest */
-#define HOST_DEV_CPORT_ID_MAX	CONFIG_HOST_DEV_CPORT_ID_MAX
-#define CPORT_ID_BAD		U16_MAX		/* UniPro max id is 4095 */
+#define CPORT_ID_MAX	CONFIG_CPORT_ID_MAX
+#define CPORT_ID_BAD	U16_MAX		/* UniPro max id is 4095 */
 
 /* For SP1 hardware, we are going to "hardcode" each device to have all logical
  * blocks in order to be able to address them as one unified "unit".  Then
@@ -198,7 +198,7 @@ static inline int is_gb_connection(const struct device *dev)
 
 static inline bool cport_id_valid(u16 cport_id)
 {
-	return cport_id != CPORT_ID_BAD;
+	return cport_id != CPORT_ID_BAD && cport_id <= CPORT_ID_MAX;
 }
 
 #endif /* __KERNEL__ */

drivers/staging/greybus/manifest.c

@@ -224,9 +224,12 @@ static u32 gb_manifest_parse_cports(struct gb_bundle *bundle)
 		if (desc_cport->bundle != bundle_id)
 			continue;
 
+		cport_id = le16_to_cpu(desc_cport->id);
+		if (cport_id > CPORT_ID_MAX)
+			goto cleanup;
+
 		/* Found one.  Set up its function structure */
 		protocol_id = desc_cport->protocol_id;
-		cport_id = le16_to_cpu(desc_cport->id);
 		if (!gb_connection_create(bundle, cport_id, protocol_id))
 			goto cleanup;