Commit c359931d authored by Peter Fink's avatar Peter Fink Committed by Marc Kleine-Budde
Browse files

can: gs_usb: use union and FLEX_ARRAY for data in struct gs_host_frame 

Modify struct gs_host_frame to make use of a union and
DECLARE_FLEX_ARRAY to be able to store different data (lengths), which
will be added in later commits.

Store the gs_host_frame length in TX direction (host -> device) in
struct gs_can::hf_size_tx and RX direction (device -> host) in struct
gs_usb::hf_size_rx so it must be calculated only once.

Link: https://lore.kernel.org/all/20220309124132.291861-15-mkl@pengutronix.de


Signed-off-by: default avatarPeter Fink <pfink@christ-es.de>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent e10ab8b3

drivers/net/can/usb/gs_usb.c

+26 −11
Original line number Diff line number Diff line
@@ -146,6 +146,10 @@ struct gs_device_bt_const { 


#define GS_CAN_FLAG_OVERFLOW BIT(0)



struct classic_can {

	u8 data[8];

} __packed;



struct gs_host_frame {

	u32 echo_id;

	__le32 can_id;
@@ -155,7 +159,9 @@ struct gs_host_frame { 
	u8 flags;

	u8 reserved;



	u8 data[8];

	union {

		DECLARE_FLEX_ARRAY(struct classic_can, classic_can);

	};

} __packed;

/* The GS USB devices make use of the same flags and masks as in

 * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
@@ -187,6 +193,8 @@ struct gs_can { 
	struct can_bittiming_const bt_const;

	unsigned int channel;	/* channel number */



	unsigned int hf_size_tx;



	/* This lock prevents a race condition between xmit and receive. */

	spinlock_t tx_ctx_lock;

	struct gs_tx_context tx_context[GS_MAX_TX_URBS];
@@ -200,6 +208,7 @@ struct gs_usb { 
	struct gs_can *canch[GS_MAX_INTF];

	struct usb_anchor rx_submitted;

	struct usb_device *udev;

	unsigned int hf_size_rx;

	u8 active_channels;

};
@@ -343,7 +352,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) 
		cf->can_id = le32_to_cpu(hf->can_id);



		can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);

		memcpy(cf->data, hf->data, 8);

		memcpy(cf->data, hf->classic_can->data, 8);



		/* ERROR frames tell us information about the controller */

		if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
@@ -398,7 +407,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) 
 resubmit_urb:

	usb_fill_bulk_urb(urb, usbcan->udev,

			  usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),

			  hf, sizeof(struct gs_host_frame),

			  hf, dev->parent->hf_size_rx,

			  gs_usb_receive_bulk_callback, usbcan);



	rc = usb_submit_urb(urb, GFP_ATOMIC);
@@ -485,7 +494,7 @@ static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, 
	if (!urb)

		goto nomem_urb;



	hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,

	hf = usb_alloc_coherent(dev->udev, dev->hf_size_tx, GFP_ATOMIC,

				&urb->transfer_dma);

	if (!hf) {

		netdev_err(netdev, "No memory left for USB buffer\n");
@@ -509,11 +518,11 @@ static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, 
	hf->can_id = cpu_to_le32(cf->can_id);

	hf->can_dlc = can_get_cc_dlc(cf, dev->can.ctrlmode);



	memcpy(hf->data, cf->data, cf->len);

	memcpy(hf->classic_can->data, cf->data, cf->len);



	usb_fill_bulk_urb(urb, dev->udev,

			  usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),

			  hf, sizeof(*hf),

			  hf, dev->hf_size_tx,

			  gs_usb_xmit_callback, txc);



	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
@@ -531,8 +540,8 @@ static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, 
		gs_free_tx_context(txc);



		usb_unanchor_urb(urb);

		usb_free_coherent(dev->udev,

				  sizeof(*hf), hf, urb->transfer_dma);

		usb_free_coherent(dev->udev, urb->transfer_buffer_length,

				  urb->transfer_buffer, urb->transfer_dma);



		if (rc == -ENODEV) {

			netif_device_detach(netdev);
@@ -552,7 +561,8 @@ static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, 
	return NETDEV_TX_OK;



 badidx:

	usb_free_coherent(dev->udev, sizeof(*hf), hf, urb->transfer_dma);

	usb_free_coherent(dev->udev, urb->transfer_buffer_length,

			  urb->transfer_buffer, urb->transfer_dma);

 nomem_hf:

	usb_free_urb(urb);
@@ -569,6 +579,7 @@ static int gs_can_open(struct net_device *netdev) 
	struct gs_usb *parent = dev->parent;

	int rc, i;

	struct gs_device_mode *dm;

	struct gs_host_frame *hf;

	u32 ctrlmode;

	u32 flags = 0;
@@ -576,6 +587,8 @@ static int gs_can_open(struct net_device *netdev) 
	if (rc)

		return rc;



	dev->hf_size_tx = struct_size(hf, classic_can, 1);



	if (!parent->active_channels) {

		for (i = 0; i < GS_MAX_RX_URBS; i++) {

			struct urb *urb;
@@ -588,7 +601,7 @@ static int gs_can_open(struct net_device *netdev) 


			/* alloc rx buffer */

			buf = usb_alloc_coherent(dev->udev,

						 sizeof(struct gs_host_frame),

						 dev->parent->hf_size_rx,

						 GFP_KERNEL,

						 &urb->transfer_dma);

			if (!buf) {
@@ -604,7 +617,7 @@ static int gs_can_open(struct net_device *netdev) 
					  usb_rcvbulkpipe(dev->udev,

							  GSUSB_ENDPOINT_IN),

					  buf,

					  sizeof(struct gs_host_frame),

					  dev->parent->hf_size_rx,

					  gs_usb_receive_bulk_callback, parent);

			urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
@@ -886,6 +899,7 @@ static int gs_usb_probe(struct usb_interface *intf, 
			const struct usb_device_id *id)

{

	struct usb_device *udev = interface_to_usbdev(intf);

	struct gs_host_frame *hf;

	struct gs_usb *dev;

	int rc = -ENOMEM;

	unsigned int icount, i;
@@ -947,6 +961,7 @@ static int gs_usb_probe(struct usb_interface *intf, 
	}



	init_usb_anchor(&dev->rx_submitted);

	dev->hf_size_rx = struct_size(hf, classic_can, 1);



	usb_set_intfdata(intf, dev);

	dev->udev = udev;