firewire: Generalize get_config_rom to get_info.

Repurpose the get_config_rom ioctl to a general get_info ioctl.
This ioctl is now used for version negotiation, and optionally
returns the config rom, and the current bus info.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/fw-device-cdev.c

@@ -68,6 +68,7 @@ struct iso_interrupt {
 };
 
 struct client {
+	u32 version;
 	struct fw_device *device;
 	spinlock_t lock;
 	struct list_head handler_list;
@@ -189,12 +190,26 @@ fw_device_op_read(struct file *file,
 	return dequeue_event(client, buffer, count);
 }
 
+static void
+fill_bus_reset_event(struct fw_cdev_event_bus_reset *event,
+		     struct fw_device *device)
+{
+	struct fw_card *card = device->card;
+
+	event->type          = FW_CDEV_EVENT_BUS_RESET;
+	event->node_id       = device->node_id;
+	event->local_node_id = card->local_node->node_id;
+	event->bm_node_id    = 0; /* FIXME: We don't track the BM. */
+	event->irm_node_id   = card->irm_node->node_id;
+	event->root_node_id  = card->root_node->node_id;
+	event->generation    = card->generation;
+}
+
 static void
 queue_bus_reset_event(struct client *client)
 {
 	struct bus_reset *bus_reset;
 	struct fw_device *device = client->device;
-	struct fw_card *card = device->card;
 
 	bus_reset = kzalloc(sizeof *bus_reset, GFP_ATOMIC);
 	if (bus_reset == NULL) {
@@ -202,13 +217,7 @@ queue_bus_reset_event(struct client *client)
 		return;
 	}
 
-	bus_reset->reset.type          = FW_CDEV_EVENT_BUS_RESET;
-	bus_reset->reset.node_id       = device->node_id;
-	bus_reset->reset.local_node_id = card->local_node->node_id;
-	bus_reset->reset.bm_node_id    = 0; /* FIXME: We don't track the BM. */
-	bus_reset->reset.irm_node_id   = card->irm_node->node_id;
-	bus_reset->reset.root_node_id  = card->root_node->node_id;
-	bus_reset->reset.generation    = card->generation;
+	fill_bus_reset_event(&bus_reset->reset, device);
 
 	queue_event(client, &bus_reset->event,
 		    &bus_reset->reset, sizeof bus_reset->reset, NULL, 0);
@@ -228,14 +237,36 @@ void fw_device_cdev_update(struct fw_device *device)
 	spin_unlock_irqrestore(&card->lock, flags);
 }
 
-static int ioctl_config_rom(struct client *client, void __user *arg)
+static int ioctl_get_info(struct client *client, void __user *arg)
 {
-	struct fw_cdev_get_config_rom rom;
+	struct fw_cdev_get_info get_info;
+	struct fw_cdev_event_bus_reset bus_reset;
+
+	if (copy_from_user(&get_info, arg, sizeof get_info))
+		return -EFAULT;
+
+	client->version = get_info.version;
+	get_info.version = FW_CDEV_VERSION;
+
+	if (get_info.rom != 0) {
+		void __user *uptr = u64_to_uptr(get_info.rom);
+		size_t length = min(get_info.rom_length,
+				    client->device->config_rom_length * 4);
+
+		if (copy_to_user(uptr, client->device->config_rom, length))
+			return -EFAULT;
+	}
+	get_info.rom_length = client->device->config_rom_length * 4;
+
+	if (get_info.bus_reset != 0) {
+		void __user *uptr = u64_to_uptr(get_info.bus_reset);
+
+		fill_bus_reset_event(&bus_reset, client->device);
+		if (copy_to_user(uptr, &bus_reset, sizeof bus_reset))
+			return -EFAULT;
+	}
 
-	rom.length = client->device->config_rom_length;
-	memcpy(rom.data, client->device->config_rom, rom.length * 4);
-	if (copy_to_user(arg, &rom,
-			 (char *)&rom.data[rom.length] - (char *)&rom))
+	if (copy_to_user(arg, &get_info, sizeof get_info))
 		return -EFAULT;
 
 	return 0;
@@ -290,7 +321,7 @@ static ssize_t ioctl_send_request(struct client *client, void __user *arg)
 	}
 
 	fw_send_request(device->card, &response->transaction,
-			request.tcode,
+			request.tcode & 0x1f,
 			device->node->node_id,
 			device->card->generation,
 			device->node->max_speed,
@@ -611,8 +642,8 @@ static int
 dispatch_ioctl(struct client *client, unsigned int cmd, void __user *arg)
 {
 	switch (cmd) {
-	case FW_CDEV_IOC_GET_CONFIG_ROM:
-		return ioctl_config_rom(client, arg);
+	case FW_CDEV_IOC_GET_INFO:
+		return ioctl_get_info(client, arg);
 	case FW_CDEV_IOC_SEND_REQUEST:
 		return ioctl_send_request(client, arg);
 	case FW_CDEV_IOC_ALLOCATE:

drivers/firewire/fw-device-cdev.h

@@ -104,7 +104,7 @@ struct fw_cdev_event_iso_interrupt {
 	__u32 header[0];
 };
 
-#define FW_CDEV_IOC_GET_CONFIG_ROM	_IOR('#', 0x00, struct fw_cdev_get_config_rom)
+#define FW_CDEV_IOC_GET_INFO		_IO('#', 0x00)
 #define FW_CDEV_IOC_SEND_REQUEST	_IO('#', 0x01)
 #define FW_CDEV_IOC_ALLOCATE		_IO('#', 0x02)
 #define FW_CDEV_IOC_SEND_RESPONSE	_IO('#', 0x03)
@@ -114,9 +114,32 @@ struct fw_cdev_event_iso_interrupt {
 #define FW_CDEV_IOC_START_ISO		_IO('#', 0x07)
 #define FW_CDEV_IOC_STOP_ISO		_IO('#', 0x08)
 
-struct fw_cdev_get_config_rom {
-	__u32 length;
-	__u32 data[256];
+/* FW_CDEV_VERSION History
+ *
+ * 1	Feb 18, 2007:  Initial version.
+ */
+#define FW_CDEV_VERSION		1
+
+struct fw_cdev_get_info {
+	/* The version field is just a running serial number.  We
+	 * never break backwards compatibility.  Userspace passes in
+	 * the version it expects and the kernel passes back the
+	 * highest version it can provide.  Even if the structs in
+	 * this interface are extended in a later version, the kernel
+	 * will not copy back more data than what was present in the
+	 * interface version userspace expects. */
+	__u32 version;
+
+	/* If non-zero, at most rom_length bytes of config rom will be
+	 * copied into that user space address.  In either case,
+	 * rom_length is updated with the actual length of the config
+	 * rom. */
+	__u32 rom_length;
+	__u64 rom;
+
+	/* If non-zero, a fw_cdev_event_bus_reset struct will be
+	 * copied here with the current state of the bus. */
+	__u64 bus_reset;
 };
 
 struct fw_cdev_send_request {