firewire: Future proof the iso ioctls by adding a handle for the iso context.

Currently create context always returns 0 and the other iso
ioctls will expect user space to pass that in for subsequent ioctls.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/fw-device-cdev.c

@@ -80,6 +80,7 @@ struct client {
 	u64 bus_reset_closure;
 
 	struct fw_iso_context *iso_context;
+	u64 iso_closure;
 	struct fw_iso_buffer buffer;
 	unsigned long vm_start;
 
@@ -626,7 +627,7 @@ iso_callback(struct fw_iso_context *context, u32 cycle,
 		return;
 
 	interrupt->interrupt.type      = FW_CDEV_EVENT_ISO_INTERRUPT;
-	interrupt->interrupt.closure   = 0;
+	interrupt->interrupt.closure   = client->iso_closure;
 	interrupt->interrupt.cycle     = cycle;
 	interrupt->interrupt.header_length = header_length;
 	memcpy(interrupt->interrupt.header, header, header_length);
@@ -659,6 +660,7 @@ static int ioctl_create_iso_context(struct client *client, void *buffer)
 		return -EINVAL;
 	}
 
+	client->iso_closure = request->closure;
 	client->iso_context = fw_iso_context_create(client->device->card,
 						    request->type,
 						    request->channel,
@@ -668,6 +670,9 @@ static int ioctl_create_iso_context(struct client *client, void *buffer)
 	if (IS_ERR(client->iso_context))
 		return PTR_ERR(client->iso_context);
 
+	/* We only support one context at this time. */
+	request->handle = 0;
+
 	return 0;
 }
 
@@ -683,7 +688,7 @@ static int ioctl_queue_iso(struct client *client, void *buffer)
 		u8 header[256];
 	} u;
 
-	if (ctx == NULL)
+	if (ctx == NULL || request->handle != 0)
 		return -EINVAL;
 
 	/* If the user passes a non-NULL data pointer, has mmap()'ed
@@ -759,6 +764,8 @@ static int ioctl_start_iso(struct client *client, void *buffer)
 {
 	struct fw_cdev_start_iso *request = buffer;
 
+	if (request->handle != 0)
+		return -EINVAL;
 	if (client->iso_context->type == FW_ISO_CONTEXT_RECEIVE) {
 		if (request->tags == 0 || request->tags > 15)
 			return -EINVAL;
@@ -773,6 +780,11 @@ static int ioctl_start_iso(struct client *client, void *buffer)
 
 static int ioctl_stop_iso(struct client *client, void *buffer)
 {
+	struct fw_cdev_stop_iso *request = buffer;
+
+	if (request->handle != 0)
+		return -EINVAL;
+
 	return fw_iso_context_stop(client->iso_context);
 }
 

drivers/firewire/fw-device-cdev.h

@@ -133,10 +133,10 @@ union fw_cdev_event {
 #define FW_CDEV_IOC_ADD_DESCRIPTOR	_IOWR('#', 0x06, struct fw_cdev_add_descriptor)
 #define FW_CDEV_IOC_REMOVE_DESCRIPTOR	_IOW('#', 0x07, struct fw_cdev_remove_descriptor)
 
-#define FW_CDEV_IOC_CREATE_ISO_CONTEXT	_IOW('#', 0x08, struct fw_cdev_create_iso_context)
+#define FW_CDEV_IOC_CREATE_ISO_CONTEXT	_IOWR('#', 0x08, struct fw_cdev_create_iso_context)
 #define FW_CDEV_IOC_QUEUE_ISO		_IOWR('#', 0x09, struct fw_cdev_queue_iso)
 #define FW_CDEV_IOC_START_ISO		_IOW('#', 0x0a, struct fw_cdev_start_iso)
-#define FW_CDEV_IOC_STOP_ISO		_IO('#', 0x0b)
+#define FW_CDEV_IOC_STOP_ISO		_IOW('#', 0x0b, struct fw_cdev_stop_iso)
 
 /* FW_CDEV_VERSION History
  *
@@ -233,6 +233,8 @@ struct fw_cdev_create_iso_context {
 	__u32 header_size;
 	__u32 channel;
 	__u32 speed;
+	__u64 closure;
+	__u32 handle;
 };
 
 struct fw_cdev_iso_packet {
@@ -249,12 +251,18 @@ struct fw_cdev_queue_iso {
 	__u64 packets;
 	__u64 data;
 	__u32 size;
+	__u32 handle;
 };
 
 struct fw_cdev_start_iso {
 	__s32 cycle;
 	__u32 sync;
 	__u32 tags;
+	__u32 handle;
+};
+
+struct fw_cdev_stop_iso {
+	__u32 handle;
 };
 
 #endif /* __fw_cdev_h */