path: root/drivers/net/thunderbolt/main.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Networking over Thunderbolt/USB4 cables using USB4NET protocol
 * (formerly Apple ThunderboltIP).
 *
 * Copyright (C) 2017, Intel Corporation
 * Authors: Amir Levy <amir.jer.levy@intel.com>
 *          Michael Jamet <michael.jamet@intel.com>
 *          Mika Westerberg <mika.westerberg@linux.intel.com>
 */

#include <linux/atomic.h>
#include <linux/ethtool.h>
#include <linux/highmem.h>
#include <linux/if_vlan.h>
#include <linux/jhash.h>
#include <linux/module.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/sizes.h>
#include <linux/thunderbolt.h>
#include <linux/uuid.h>
#include <linux/workqueue.h>

#include <net/ip6_checksum.h>

#include "trace.h"

/* Protocol timeouts in ms */
#define TBNET_LOGIN_DELAY	4500
#define TBNET_LOGIN_TIMEOUT	500
#define TBNET_LOGOUT_TIMEOUT	1000

#define TBNET_RING_SIZE		256
#define TBNET_LOGIN_RETRIES	60
#define TBNET_LOGOUT_RETRIES	10
#define TBNET_E2E		BIT(0)
#define TBNET_MATCH_FRAGS_ID	BIT(1)
#define TBNET_64K_FRAMES	BIT(2)
#define TBNET_MAX_MTU		SZ_64K
#define TBNET_FRAME_SIZE	SZ_4K
#define TBNET_MAX_PAYLOAD_SIZE	\
	(TBNET_FRAME_SIZE - sizeof(struct thunderbolt_ip_frame_header))
/* Rx packets need to hold space for skb_shared_info */
#define TBNET_RX_MAX_SIZE	\
	(TBNET_FRAME_SIZE + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
#define TBNET_RX_PAGE_ORDER	get_order(TBNET_RX_MAX_SIZE)
#define TBNET_RX_PAGE_SIZE	(PAGE_SIZE << TBNET_RX_PAGE_ORDER)

#define TBNET_L0_PORT_NUM(route) ((route) & GENMASK(5, 0))

/**
 * struct thunderbolt_ip_frame_header - Header for each Thunderbolt frame
 * @frame_size: size of the data with the frame
 * @frame_index: running index on the frames
 * @frame_id: ID of the frame to match frames to specific packet
 * @frame_count: how many frames assembles a full packet
 *
 * Each data frame passed to the high-speed DMA ring has this header. If
 * the XDomain network directory announces that %TBNET_MATCH_FRAGS_ID is
 * supported then @frame_id is filled, otherwise it stays %0.
 */
struct thunderbolt_ip_frame_header {
	__le32 frame_size;
	__le16 frame_index;
	__le16 frame_id;
	__le32 frame_count;
};

enum thunderbolt_ip_frame_pdf {
	TBIP_PDF_FRAME_START = 1,
	TBIP_PDF_FRAME_END,
};

enum thunderbolt_ip_type {
	TBIP_LOGIN,
	TBIP_LOGIN_RESPONSE,
	TBIP_LOGOUT,
	TBIP_STATUS,
};

struct thunderbolt_ip_header {
	u32 route_hi;
	u32 route_lo;
	u32 length_sn;
	uuid_t uuid;
	uuid_t initiator_uuid;
	uuid_t target_uuid;
	u32 type;
	u32 command_id;
};

#define TBIP_HDR_LENGTH_MASK		GENMASK(5, 0)
#define TBIP_HDR_SN_MASK		GENMASK(28, 27)
#define TBIP_HDR_SN_SHIFT		27

struct thunderbolt_ip_login {
	struct thunderbolt_ip_header hdr;
	u32 proto_version;
	u32 transmit_path;
	u32 reserved[4];
};

#define TBIP_LOGIN_PROTO_VERSION	1

struct thunderbolt_ip_login_response {
	struct thunderbolt_ip_header hdr;
	u32 status;
	u32 receiver_mac[2];
	u32 receiver_mac_len;
	u32 reserved[4];
};

struct thunderbolt_ip_logout {
	struct thunderbolt_ip_header hdr;
};

struct thunderbolt_ip_status {
	struct thunderbolt_ip_header hdr;
	u32 status;
};

struct tbnet_stats {
	u64 tx_packets;
	u64 rx_packets;
	u64 tx_bytes;
	u64 rx_bytes;
	u64 rx_errors;
	u64 tx_errors;
	u64 rx_length_errors;
	u64 rx_over_errors;
	u64 rx_crc_errors;
	u64 rx_missed_errors;
};

struct tbnet_frame {
	struct net_device *dev;
	struct page *page;
	struct ring_frame frame;
};

struct tbnet_ring {
	struct tbnet_frame frames[TBNET_RING_SIZE];
	unsigned int cons;
	unsigned int prod;
	struct tb_ring *ring;
};

/**
 * struct tbnet - ThunderboltIP network driver private data
 * @svc: XDomain service the driver is bound to
 * @xd: XDomain the service belongs to
 * @handler: ThunderboltIP configuration protocol handler
 * @dev: Networking device
 * @napi: NAPI structure for Rx polling
 * @stats: Network statistics
 * @skb: Network packet that is currently processed on Rx path
 * @command_id: ID used for next configuration protocol packet
 * @login_sent: ThunderboltIP login message successfully sent
 * @login_received: ThunderboltIP login message received from the remote
 *		    host
 * @local_transmit_path: HopID we are using to send out packets
 * @remote_transmit_path: HopID the other end is using to send packets to us
 * @connection_lock: Lock serializing access to @login_sent,
 *		     @login_received and @transmit_path.
 * @login_retries: Number of login retries currently done
 * @login_work: Worker to send ThunderboltIP login packets
 * @connected_work: Worker that finalizes the ThunderboltIP connection
 *		    setup and enables DMA paths for high speed data
 *		    transfers
 * @disconnect_work: Worker that handles tearing down the ThunderboltIP
 *		     connection
 * @rx_hdr: Copy of the currently processed Rx frame. Used when a
 *	    network packet consists of multiple Thunderbolt frames.
 *	    In host byte order.
 * @rx_ring: Software ring holding Rx frames
 * @frame_id: Frame ID use for next Tx packet
 *            (if %TBNET_MATCH_FRAGS_ID is supported in both ends)
 * @tx_ring: Software ring holding Tx frames
 */
struct tbnet {
	const struct tb_service *svc;
	struct tb_xdomain *xd;
	struct tb_protocol_handler handler;
	struct net_device *dev;
	struct napi_struct napi;
	struct tbnet_stats stats;
	struct sk_buff *skb;
	atomic_t command_id;
	bool login_sent;
	bool login_received;
	int local_transmit_path;
	int remote_transmit_path;
	struct mutex connection_lock;
	int login_retries;
	struct delayed_work login_work;
	struct work_struct connected_work;
	struct work_struct disconnect_work;
	struct thunderbolt_ip_frame_header rx_hdr;
	struct tbnet_ring rx_ring;
	atomic_t frame_id;
	struct tbnet_ring tx_ring;
};

/* Network property directory UUID: c66189ca-1cce-4195-bdb8-49592e5f5a4f */
static const uuid_t tbnet_dir_uuid =
	UUID_INIT(0xc66189ca, 0x1cce, 0x4195,
		  0xbd, 0xb8, 0x49, 0x59, 0x2e, 0x5f, 0x5a, 0x4f);

/* ThunderboltIP protocol UUID: 798f589e-3616-8a47-97c6-5664a920c8dd */
static const uuid_t tbnet_svc_uuid =
	UUID_INIT(0x798f589e, 0x3616, 0x8a47,
		  0x97, 0xc6, 0x56, 0x64, 0xa9, 0x20, 0xc8, 0xdd);

static struct tb_property_dir *tbnet_dir;

static bool tbnet_e2e = true;
module_param_named(e2e, tbnet_e2e, bool, 0444);
MODULE_PARM_DESC(e2e, "USB4NET full end-to-end flow control (default: true)");

static void tbnet_fill_header(struct thunderbolt_ip_header *hdr, u64 route,
	u8 sequence, const uuid_t *initiator_uuid, const uuid_t *target_uuid,
	enum thunderbolt_ip_type type, size_t size, u32 command_id)
{
	u32 length_sn;

	/* Length does not include route_hi/lo and length_sn fields */
	length_sn = (size - 3 * 4) / 4;
	length_sn |= (sequence << TBIP_HDR_SN_SHIFT) & TBIP_HDR_SN_MASK;

	hdr->route_hi = upper_32_bits(route);
	hdr->route_lo = lower_32_bits(route);
	hdr->length_sn = length_sn;
	uuid_copy(&hdr->uuid, &tbnet_svc_uuid);
	uuid_copy(&hdr->initiator_uuid, initiator_uuid);
	uuid_copy(&hdr->target_uuid, target_uuid);
	hdr->type = type;
	hdr->command_id = command_id;
}

static int tbnet_login_response(struct tbnet *net, u64 route, u8 sequence,
				u32 command_id)
{
	struct thunderbolt_ip_login_response reply;
	struct tb_xdomain *xd = net->xd;

	memset(&reply, 0, sizeof(reply));
	tbnet_fill_header(&reply.hdr, route, sequence, xd->local_uuid,
			  xd->remote_uuid, TBIP_LOGIN_RESPONSE, sizeof(reply),
			  command_id);
	memcpy(reply.receiver_mac, net->dev->dev_addr, ETH_ALEN);
	reply.receiver_mac_len = ETH_ALEN;

	return tb_xdomain_response(xd, &reply, sizeof(reply),
				   TB_CFG_PKG_XDOMAIN_RESP);
}

static int tbnet_login_request(struct tbnet *net, u8 sequence)
{
	struct thunderb