Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 1082 insertions, 0 deletions

diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c
new file mode 100644
index 000000000..0c661a706
--- /dev/null
+++ b/drivers/thunderbolt/ctl.c
@@ -0,0 +1,1082 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt driver - control channel and configuration commands
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ * Copyright (C) 2018, Intel Corporation
+ */
+
+#include <linux/crc32.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/dmapool.h>
+#include <linux/workqueue.h>
+
+#include "ctl.h"
+
+
+#define TB_CTL_RX_PKG_COUNT	10
+#define TB_CTL_RETRIES		4
+
+/**
+ * struct tb_ctl - Thunderbolt control channel
+ * @nhi: Pointer to the NHI structure
+ * @tx: Transmit ring
+ * @rx: Receive ring
+ * @frame_pool: DMA pool for control messages
+ * @rx_packets: Received control messages
+ * @request_queue_lock: Lock protecting @request_queue
+ * @request_queue: List of outstanding requests
+ * @running: Is the control channel running at the moment
+ * @timeout_msec: Default timeout for non-raw control messages
+ * @callback: Callback called when hotplug message is received
+ * @callback_data: Data passed to @callback
+ */
+struct tb_ctl {
+	struct tb_nhi *nhi;
+	struct tb_ring *tx;
+	struct tb_ring *rx;
+
+	struct dma_pool *frame_pool;
+	struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT];
+	struct mutex request_queue_lock;
+	struct list_head request_queue;
+	bool running;
+
+	int timeout_msec;
+	event_cb callback;
+	void *callback_data;
+};
+
+
+#define tb_ctl_WARN(ctl, format, arg...) \
+	dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_err(ctl, format, arg...) \
+	dev_err(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_warn(ctl, format, arg...) \
+	dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_info(ctl, format, arg...) \
+	dev_info(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_dbg(ctl, format, arg...) \
+	dev_dbg(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+static DECLARE_WAIT_QUEUE_HEAD(tb_cfg_request_cancel_queue);
+/* Serializes access to request kref_get/put */
+static DEFINE_MUTEX(tb_cfg_request_lock);
+
+/**
+ * tb_cfg_request_alloc() - Allocates a new config request
+ *
+ * This is refcounted object so when you are done with this, call
+ * tb_cfg_request_put() to it.
+ */
+struct tb_cfg_request *tb_cfg_request_alloc(void)
+{
+	struct tb_cfg_request *req;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return NULL;
+
+	kref_init(&req->kref);
+
+	return req;
+}
+
+/**
+ * tb_cfg_request_get() - Increase refcount of a request
+ * @req: Request whose refcount is increased
+ */
+void tb_cfg_request_get(struct tb_cfg_request *req)
+{
+	mutex_lock(&tb_cfg_request_lock);
+	kref_get(&req->kref);
+	mutex_unlock(&tb_cfg_request_lock);
+}
+
+static void tb_cfg_request_destroy(struct kref *kref)
+{
+	struct tb_cfg_request *req = container_of(kref, typeof(*req), kref);
+
+	kfree(req);
+}
+
+/**
+ * tb_cfg_request_put() - Decrease refcount and possibly release the request
+ * @req: Request whose refcount is decreased
+ *
+ * Call this function when you are done with the request. When refcount
+ * goes to %0 the object is released.
+ */
+void tb_cfg_request_put(struct tb_cfg_request *req)
+{
+	mutex_lock(&tb_cfg_request_lock);
+	kref_put(&req->kref, tb_cfg_request_destroy);
+	mutex_unlock(&tb_cfg_request_lock);
+}
+
+static int tb_cfg_request_enqueue(struct tb_ctl *ctl,
+				  struct tb_cfg_request *req)
+{
+	WARN_ON(test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags));
+	WARN_ON(req->ctl);
+
+	mutex_lock(&ctl->request_queue_lock);
+	if (!ctl->running) {
+		mutex_unlock(&ctl->request_queue_lock);
+		return -ENOTCONN;
+	}
+	req->ctl = ctl;
+	list_add_tail(&req->list, &ctl->request_queue);
+	set_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
+	mutex_unlock(&ctl->request_queue_lock);
+	return 0;
+}
+
+static void tb_cfg_request_dequeue(struct tb_cfg_request *req)
+{
+	struct tb_ctl *ctl = req->ctl;
+
+	mutex_lock(&ctl->request_queue_lock);
+	list_del(&req->list);
+	clear_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
+	if (test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))
+		wake_up(&tb_cfg_request_cancel_queue);
+	mutex_unlock(&ctl->request_queue_lock);
+}
+
+static bool tb_cfg_request_is_active(struct tb_cfg_request *req)
+{
+	return test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
+}
+
+static struct tb_cfg_request *
+tb_cfg_request_find(struct tb_ctl *ctl, struct ctl_pkg *pkg)
+{
+	struct tb_cfg_request *req = NULL, *iter;
+
+	mutex_lock(&pkg->ctl->request_queue_lock);
+	list_for_each_entry(iter, &pkg->ctl->request_queue, list) {
+		tb_cfg_request_get(iter);
+		if (iter->match(iter, pkg)) {
+			req = iter;
+			break;
+		}
+		tb_cfg_request_put(iter);
+	}
+	mutex_unlock(&pkg->ctl->request_queue_lock);
+
+	return req;
+}
+
+/* utility functions */
+
+
+static int check_header(const struct ctl_pkg *pkg, u32 len,
+			enum tb_cfg_pkg_type type, u64 route)
+{
+	struct tb_cfg_header *header = pkg->buffer;
+
+	/* check frame, TODO: frame flags */
+	if (WARN(len != pkg->frame.size,
+			"wrong framesize (expected %#x, got %#x)\n",
+			len, pkg->frame.size))
+		return -EIO;
+	if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n",
+			type, pkg->frame.eof))
+		return -EIO;
+	if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n",
+			pkg->frame.sof))
+		return -EIO;
+
+	/* check header */
+	if (WARN(header->unknown != 1 << 9,
+			"header->unknown is %#x\n", header->unknown))
+		return -EIO;
+	if (WARN(route != tb_cfg_get_route(header),
+			"wrong route (expected %llx, got %llx)",
+			route, tb_cfg_get_route(header)))
+		return -EIO;
+	return 0;
+}
+
+static int check_config_address(struct tb_cfg_address addr,
+				enum tb_cfg_space space, u32 offset,
+				u32 length)
+{
+	if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero))
+		return -EIO;
+	if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)",
+			space, addr.space))
+		return -EIO;
+	if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)",
+			offset, addr.offset))
+		return -EIO;
+	if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)",
+			length, addr.length))
+		return -EIO;
+	/*
+	 * We cannot check addr->port as it is set to the upstream port of the
+	 * sender.
+	 */
+	return 0;
+}
+
+static struct tb_cfg_result decode_error(const struct ctl_pkg *response)
+{
+	struct cfg_error_pkg *pkg = response->buffer;
+	struct tb_ctl *ctl = response->ctl;
+	struct tb_cfg_result res = { 0 };
+	res.response_route = tb_cfg_get_route(&pkg->header);
+	res.response_port = 0;
+	res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR,
+			       tb_cfg_get_route(&pkg->header));
+	if (res.err)
+		return res;
+
+	if (pkg->zero1)
+		tb_ctl_warn(ctl, "pkg->zero1 is %#x\n", pkg->zero1);
+	if (pkg->zero2)
+		tb_ctl_warn(ctl, "pkg->zero2 is %#x\n", pkg->zero2);
+	if (pkg->zero3)
+		tb_ctl_warn(ctl, "pkg->zero3 is %#x\n", pkg->zero3);
+
+	res.err = 1;
+	res.tb_error = pkg->error;
+	res.response_port = pkg->port;
+	return res;
+
+}
+
+static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len,
+					 enum tb_cfg_pkg_type type, u64 route)
+{
+	struct tb_cfg_header *header = pkg->buffer;
+	struct tb_cfg_result res = { 0 };
+
+	if (pkg->frame.eof == TB_CFG_PKG_ERROR)
+		return decode_error(pkg);
+
+	res.response_port = 0; /* will be updated later for cfg_read/write */
+	res.response_route = tb_cfg_get_route(header);
+	res.err = check_header(pkg, len, type, route);
+	return res;
+}
+
+static void tb_cfg_print_error(struct tb_ctl *ctl,
+			       const struct tb_cfg_result *res)
+{
+	WARN_ON(res->err != 1);
+	switch (res->tb_error) {
+	case TB_CFG_ERROR_PORT_NOT_CONNECTED:
+		/* Port is not connected. This can happen during surprise
+		 * removal. Do not warn. */
+		return;
+	case TB_CFG_ERROR_INVALID_CONFIG_SPACE:
+		/*
+		 * Invalid cfg_space/offset/length combination in
+		 * cfg_read/cfg_write.
+		 */
+		tb_ctl_dbg(ctl, "%llx:%x: invalid config space or offset\n",
+			   res->response_route, res->response_port);
+		return;
+	case TB_CFG_ERROR_NO_SUCH_PORT:
+		/*
+		 * - The route contains a non-existent port.
+		 * - The route contains a non-PHY port (e.g. PCIe).
+		 * - The port in cfg_read/cfg_write does not exist.
+		 */
+		tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",
+			res->response_route, res->response_port);
+		return;
+	case TB_CFG_ERROR_LOOP:
+		tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",
+			res->response_route, res->response_port);
+		return;
+	case TB_CFG_ERROR_LOCK:
+		tb_ctl_warn(ctl, "%llx:%x: downstream port is locked\n",
+			    res->response_route, res->response_port);
+		return;
+	default:
+		/* 5,6,7,9 and 11 are also valid error codes */
+		tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",
+			res->response_route, res->response_port);
+		return;
+	}
+}
+
+static __be32 tb_crc(const void *data, size_t len)
+{
+	return cpu_to_be32(~__crc32c_le(~0, data, len));
+}
+
+static void tb_ctl_pkg_free(struct ctl_pkg *pkg)
+{
+	if (pkg) {
+		dma_pool_free(pkg->ctl->frame_pool,
+			      pkg->buffer, pkg->frame.buffer_phy);
+		kfree(pkg);
+	}
+}
+
+static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl)
+{
+	struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL);
+	if (!pkg)
+		return NULL;
+	pkg->ctl = ctl;
+	pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL,
+				     &pkg->frame.buffer_phy);
+	if (!pkg->buffer) {
+		kfree(pkg);
+		return NULL;
+	}
+	return pkg;
+}
+
+
+/* RX/TX handling */
+
+static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
+			       bool canceled)
+{
+	struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
+	tb_ctl_pkg_free(pkg);
+}
+
+/*
+ * tb_cfg_tx() - transmit a packet on the control channel
+ *
+ * len must be a multiple of four.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len,
+		     enum tb_cfg_pkg_type type)
+{
+	int res;
+	struct ctl_pkg *pkg;
+	if (len % 4 != 0) { /* required for le->be conversion */
+		tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);
+		return -EINVAL;
+	}
+	if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */
+		tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",
+			    len, TB_FRAME_SIZE - 4);
+		return -EINVAL;
+	}
+	pkg = tb_ctl_pkg_alloc(ctl);
+	if (!pkg)
+		return -ENOMEM;
+	pkg->frame.callback = tb_ctl_tx_callback;
+	pkg->frame.size = len + 4;
+	pkg->frame.sof = type;
+	pkg->frame.eof = type;
+	cpu_to_be32_array(pkg->buffer, data, len / 4);
+	*(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len);
+
+	res = tb_ring_tx(ctl->tx, &pkg->frame);
+	if (res) /* ring is stopped */
+		tb_ctl_pkg_free(pkg);
+	return res;
+}
+
+/*
+ * tb_ctl_handle_event() - acknowledge a plug event, invoke ctl->callback
+ */
+static bool tb_ctl_handle_event(struct tb_ctl *ctl, enum tb_cfg_pkg_type type,
+				struct ctl_pkg *pkg, size_t size)
+{
+	return ctl->callback(ctl->callback_data, type, pkg->buffer, size);
+}
+
+static void tb_ctl_rx_submit(struct ctl_pkg *pkg)
+{
+	tb_ring_rx(pkg->ctl->rx, &pkg->frame); /*
+					     * We ignore failures during stop.
+					     * All rx packets are referenced
+					     * from ctl->rx_packets, so we do
+					     * not loose them.
+					     */
+}
+
+static int tb_async_error(const struct ctl_pkg *pkg)
+{
+	const struct cfg_error_pkg *error = pkg->buffer;
+
+	if (pkg->frame.eof != TB_CFG_PKG_ERROR)
+		return false;
+
+	switch (error->error) {
+	case TB_CFG_ERROR_LINK_ERROR:
+	case TB_CFG_ERROR_HEC_ERROR_DETECTED:
+	case TB_CFG_ERROR_FLOW_CONTROL_ERROR:
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
+			       bool canceled)
+{
+	struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
+	struct tb_cfg_request *req;
+	__be32 crc32;
+
+	if (canceled)
+		return; /*
+			 * ring is stopped, packet is referenced from
+			 * ctl->rx_packets.
+			 */
+
+	if (frame->size < 4 || frame->size % 4 != 0) {
+		tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",
+			   frame->size);
+		goto rx;
+	}
+
+	frame->size -= 4; /* remove checksum */
+	crc32 = tb_crc(pkg->buffer, frame->size);
+	be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);
+
+	switch (frame->eof) {
+	case TB_CFG_PKG_READ:
+	case TB_CFG_PKG_WRITE:
+	case TB_CFG_PKG_ERROR:
+	case TB_CFG_PKG_OVERRIDE:
+	case TB_CFG_PKG_RESET:
+		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
+			tb_ctl_err(pkg->ctl,
+				   "RX: checksum mismatch, dropping packet\n");
+			goto rx;
+		}
+		if (tb_async_error(pkg)) {
+			tb_ctl_handle_event(pkg->ctl, frame->eof,
+					    pkg, frame->size);
+			goto rx;
+		}
+		break;
+
+	case TB_CFG_PKG_EVENT:
+	case TB_CFG_PKG_XDOMAIN_RESP:
+	case TB_CFG_PKG_XDOMAIN_REQ:
+		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
+			tb_ctl_err(pkg->ctl,
+				   "RX: checksum mismatch, dropping packet\n");
+			goto rx;
+		}
+		fallthrough;
+	case TB_CFG_PKG_ICM_EVENT:
+		if (tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size))
+			goto rx;
+		break;
+
+	default:
+		break;
+	}
+
+	/*
+	 * The received packet will be processed only if there is an
+	 * active request and that the packet is what is expected. This
+	 * prevents packets such as replies coming after timeout has
+	 * triggered from messing with the active requests.
+	 */
+	req = tb_cfg_request_find(pkg->ctl, pkg);
+	if (req) {
+		if (req->copy(req, pkg))
+			schedule_work(&req->work);
+		tb_cfg_request_put(req);
+	}
+
+rx:
+	tb_ctl_rx_submit(pkg);
+}
+
+static void tb_cfg_request_work(struct work_struct *work)
+{
+	struct tb_cfg_request *req = container_of(work, typeof(*req), work);
+
+	if (!test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))
+		req->callback(req->callback_data);
+
+	tb_cfg_request_dequeue(req);
+	tb_cfg_request_put(req);
+}
+
+/**
+ * tb_cfg_request() - Start control request not waiting for it to complete
+ * @ctl: Control channel to use
+ * @req: Request to start
+ * @callback: Callback called when the request is completed
+ * @callback_data: Data to be passed to @callback
+ *
+ * This queues @req on the given control channel without waiting for it
+ * to complete. When the request completes @callback is called.
+ */
+int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req,
+		   void (*callback)(void *), void *callback_data)
+{
+	int ret;
+
+	req->flags = 0;
+	req->callback = callback;
+	req->callback_data = callback_data;
+	INIT_WORK(&req->work, tb_cfg_request_work);
+	INIT_LIST_HEAD(&req->list);
+
+	tb_cfg_request_get(req);
+	ret = tb_cfg_request_enqueue(ctl, req);
+	if (ret)
+		goto err_put;
+
+	ret = tb_ctl_tx(ctl, req->request, req->request_size,
+			req->request_type);
+	if (ret)
+		goto err_dequeue;
+
+	if (!req->response)
+		schedule_work(&req->work);
+
+	return 0;
+
+err_dequeue:
+	tb_cfg_request_dequeue(req);
+err_put:
+	tb_cfg_request_put(req);
+
+	return ret;
+}
+
+/**
+ * tb_cfg_request_cancel() - Cancel a control request
+ * @req: Request to cancel
+ * @err: Error to assign to the request
+ *
+ * This function can be used to cancel ongoing request. It will wait
+ * until the request is not active anymore.
+ */
+void tb_cfg_request_cancel(struct tb_cfg_request *req, int err)
+{
+	set_bit(TB_CFG_REQUEST_CANCELED, &req->flags);
+	schedule_work(&req->work);
+	wait_event(tb_cfg_request_cancel_queue, !tb_cfg_request_is_active(req));
+	req->result.err = err;
+}
+
+static void tb_cfg_request_complete(void *data)
+{
+	complete(data);
+}
+
+/**
+ * tb_cfg_request_sync() - Start control request and wait until it completes
+ * @ctl: Control channel to use
+ * @req: Request to start
+ * @timeout_msec: Timeout how long to wait @req to complete
+ *
+ * Starts a control request and waits until it completes. If timeout
+ * triggers the request is canceled before function returns. Note the
+ * caller needs to make sure only one message for given switch is active
+ * at a time.
+ */
+struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl,
+					 struct tb_cfg_request *req,
+					 int timeout_msec)
+{
+	unsigned long timeout = msecs_to_jiffies(timeout_msec);
+	struct tb_cfg_result res = { 0 };
+	DECLARE_COMPLETION_ONSTACK(done);
+	int ret;
+
+	ret = tb_cfg_request(ctl, req, tb_cfg_request_complete, &done);
+	if (ret) {
+		res.err = ret;
+		return res;
+	}
+
+	if (!wait_for_completion_timeout(&done, timeout))
+		tb_cfg_request_cancel(req, -ETIMEDOUT);
+
+	flush_work(&req->work);
+
+	return req->result;
+}
+
+/* public interface, alloc/start/stop/free */
+
+/**
+ * tb_ctl_alloc() - allocate a control channel
+ * @nhi: Pointer to NHI
+ * @timeout_msec: Default timeout used with non-raw control messages
+ * @cb: Callback called for plug events
+ * @cb_data: Data passed to @cb
+ *
+ * cb will be invoked once for every hot plug event.
+ *
+ * Return: Returns a pointer on success or NULL on failure.
+ */
+struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int timeout_msec, event_cb cb,
+			    void *cb_data)
+{
+	int i;
+	struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
+	if (!ctl)
+		return NULL;
+	ctl->nhi = nhi;
+	ctl->timeout_msec = timeout_msec;
+	ctl->callback = cb;
+	ctl->callback_data = cb_data;
+
+	mutex_init(&ctl->request_queue_lock);
+	INIT_LIST_HEAD(&ctl->request_queue);
+	ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev,
+					 TB_FRAME_SIZE, 4, 0);
+	if (!ctl->frame_pool)
+		goto err;
+
+	ctl->tx = tb_ring_alloc_tx(nhi, 0, 10, RING_FLAG_NO_SUSPEND);
+	if (!ctl->tx)
+		goto err;
+
+	ctl->rx = tb_ring_alloc_rx(nhi, 0, 10, RING_FLAG_NO_SUSPEND, 0, 0xffff,
+				   0xffff, NULL, NULL);
+	if (!ctl->rx)
+		goto err;
+
+	for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) {
+		ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl);
+		if (!ctl->rx_packets[i])
+			goto err;
+		ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback;
+	}
+
+	tb_ctl_dbg(ctl, "control channel created\n");
+	return ctl;
+err:
+	tb_ctl_free(ctl);
+	return NULL;
+}
+
+/**
+ * tb_ctl_free() - free a control channel
+ * @ctl: Control channel to free
+ *
+ * Must be called after tb_ctl_stop.
+ *
+ * Must NOT be called from ctl->callback.
+ */
+void tb_ctl_free(struct tb_ctl *ctl)
+{
+	int i;
+
+	if (!ctl)
+		return;
+
+	if (ctl->rx)
+		tb_ring_free(ctl->rx);
+	if (ctl->tx)
+		tb_ring_free(ctl->tx);
+
+	/* free RX packets */
+	for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
+		tb_ctl_pkg_free(ctl->rx_packets[i]);
+
+
+	dma_pool_destroy(ctl->frame_pool);
+	kfree(ctl);
+}
+
+/**
+ * tb_ctl_start() - start/resume the control channel
+ * @ctl: Control channel to start
+ */
+void tb_ctl_start(struct tb_ctl *ctl)
+{
+	int i;
+	tb_ctl_dbg(ctl, "control channel starting...\n");
+	tb_ring_start(ctl->tx); /* is used to ack hotplug packets, start first */
+	tb_ring_start(ctl->rx);
+	for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
+		tb_ctl_rx_submit(ctl->rx_packets[i]);
+
+	ctl->running = true;
+}
+
+/**
+ * tb_ctl_stop() - pause the control channel
+ * @ctl: Control channel to stop
+ *
+ * All invocations of ctl->callback will have finished after this method
+ * returns.
+ *
+ * Must NOT be called from ctl->callback.
+ */
+void tb_ctl_stop(struct tb_ctl *ctl)
+{
+	mutex_lock(&ctl->request_queue_lock);
+	ctl->running = false;
+	mutex_unlock(&ctl->request_queue_lock);
+
+	tb_ring_stop(ctl->rx);
+	tb_ring_stop(ctl->tx);
+
+	if (!list_empty(&ctl->request_queue))
+		tb_ctl_WARN(ctl, "dangling request in request_queue\n");
+	INIT_LIST_HEAD(&ctl->request_queue);
+	tb_ctl_dbg(ctl, "control channel stopped\n");
+}
+
+/* public interface, commands */
+
+/**
+ * tb_cfg_ack_plug() - Ack hot plug/unplug event
+ * @ctl: Control channel to use
+ * @route: Router that originated the event
+ * @port: Port where the hot plug/unplug happened
+ * @unplug: Ack hot plug or unplug
+ *
+ * Call this as response for hot plug/unplug event to ack it.
+ * Returns %0 on success or an error code on failure.
+ */
+int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug)
+{
+	struct cfg_error_pkg pkg = {
+		.header = tb_cfg_make_header(route),
+		.port = port,
+		.error = TB_CFG_ERROR_ACK_PLUG_EVENT,
+		.pg = unplug ? TB_CFG_ERROR_PG_HOT_UNPLUG
+			     : TB_CFG_ERROR_PG_HOT_PLUG,
+	};
+	tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%x\n",
+		   unplug ? "un" : "", route, port);
+	return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
+}
+
+static bool tb_cfg_match(const struct tb_cfg_request *req,
+			 const struct ctl_pkg *pkg)
+{
+	u64 route = tb_cfg_get_route(pkg->buffer) & ~BIT_ULL(63);
+
+	if (pkg->frame.eof == TB_CFG_PKG_ERROR)
+		return true;
+
+	if (pkg->frame.eof != req->response_type)
+		return false;
+	if (route != tb_cfg_get_route(req->request))
+		return false;
+	if (pkg->frame.size != req->response_size)
+		return false;
+
+	if (pkg->frame.eof == TB_CFG_PKG_READ ||
+	    pkg->frame.eof == TB_CFG_PKG_WRITE) {
+		const struct cfg_read_pkg *req_hdr = req->request;
+		const struct cfg_read_pkg *res_hdr = pkg->buffer;
+
+		if (req_hdr->addr.seq != res_hdr->addr.seq)
+			return false;
+	}
+
+	return true;
+}
+
+static bool tb_cfg_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg)
+{
+	struct tb_cfg_result res;
+
+	/* Now make sure it is in expected format */
+	res = parse_header(pkg, req->response_size, req->response_type,
+			   tb_cfg_get_route(req->request));
+	if (!res.err)
+		memcpy(req->response, pkg->buffer, req->response_size);
+
+	req->result = res;
+
+	/* Always complete when first response is received */
+	return true;
+}
+
+/**
+ * tb_cfg_reset() - send a reset packet and wait for a response
+ * @ctl: Control channel pointer
+ * @route: Router string for the router to send reset
+ *
+ * If the switch at route is incorrectly configured then we will not receive a
+ * reply (even though the switch will reset). The caller should check for
+ * -ETIMEDOUT and attempt to reconfigure the switch.
+ */
+struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route)
+{
+	struct cfg_reset_pkg request = { .header = tb_cfg_make_header(route) };
+	struct tb_cfg_result res = { 0 };
+	struct tb_cfg_header reply;
+	struct tb_cfg_request *req;
+
+	req = tb_cfg_request_alloc();
+	if (!req) {
+		res.err = -ENOMEM;
+		return res;
+	}
+
+	req->match = tb_cfg_match;
+	req->copy = tb_cfg_copy;
+	req->request = &request;
+	req->request_size = sizeof(request);
+	req->request_type = TB_CFG_PKG_RESET;
+	req->response = &reply;
+	req->response_size = sizeof(reply);
+	req->response_type = TB_CFG_PKG_RESET;
+
+	res = tb_cfg_request_sync(ctl, req, ctl->timeout_msec);
+
+	tb_cfg_request_put(req);
+
+	return res;
+}
+
+/**
+ * tb_cfg_read_raw() - read from config space into buffer
+ * @ctl: Pointer to the control channel
+ * @buffer: Buffer where the data is read
+ * @route: Route string of the router
+ * @port: Port number when reading from %TB_CFG_PORT, %0 otherwise
+ * @space: Config space selector
+ * @offset: Dword word offset of the register to start reading
+ * @length: Number of dwords to read
+ * @timeout_msec: Timeout in ms how long to wait for the response
+ *
+ * Reads from router config space without translating the possible error.
+ */
+struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
+		u64 route, u32 port, enum tb_cfg_space space,
+		u32 offset, u32 length, int timeout_msec)
+{
+	struct tb_cfg_result res = { 0 };
+	struct cfg_read_pkg request = {
+		.header = tb_cfg_make_header(route),
+		.addr = {
+			.port = port,
+			.space = space,
+			.offset = offset,
+			.length = length,
+		},
+	};
+	struct cfg_write_pkg reply;
+	int retries = 0;
+
+	while (retries < TB_CTL_RETRIES) {
+		struct tb_cfg_request *req;
+
+		req = tb_cfg_request_alloc();
+		if (!req) {
+			res.err = -ENOMEM;
+			return res;
+		}
+
+		request.addr.seq = retries++;
+
+		req->match = tb_cfg_match;
+		req->copy = tb_cfg_copy;
+		req->request = &request;
+		req->request_size = sizeof(request);
+		req->request_type = TB_CFG_PKG_READ;
+		req->response = &reply;
+		req->response_size = 12 + 4 * length;
+		req->response_type = TB_CFG_PKG_READ;
+
+		res = tb_cfg_request_sync(ctl, req, timeout_msec);
+
+		tb_cfg_request_put(req);
+
+		if (res.err != -ETIMEDOUT)
+			break;
+
+		/* Wait a bit (arbitrary time) until we send a retry */
+		usleep_range(10, 100);
+	}
+
+	if (res.err)
+		return res;
+
+	res.response_port = reply.addr.port;
+	res.err = check_config_address(reply.addr, space, offset, length);
+	if (!res.err)
+		memcpy(buffer, &reply.data, 4 * length);
+	return res;
+}
+
+/**
+ * tb_cfg_write_raw() - write from buffer into config space
+ * @ctl: Pointer to the control channel
+ * @buffer: Data to write
+ * @route: Route string of the router
+ * @port: Port number when writing to %TB_CFG_PORT, %0 otherwise
+ * @space: Config space selector
+ * @offset: Dword word offset of the register to start writing
+ * @length: Number of dwords to write
+ * @timeout_msec: Timeout in ms how long to wait for the response
+ *
+ * Writes to router config space without translating the possible error.
+ */
+struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer,
+		u64 route, u32 port, enum tb_cfg_space space,
+		u32 offset, u32 length, int timeout_msec)
+{
+	struct tb_cfg_result res = { 0 };
+	struct cfg_write_pkg request = {
+		.header = tb_cfg_make_header(route),
+		.addr = {
+			.port = port,
+			.space = space,
+			.offset = offset,
+			.length = length,
+		},
+	};
+	struct cfg_read_pkg reply;
+	int retries = 0;
+
+	memcpy(&request.data, buffer, length * 4);
+
+	while (retries < TB_CTL_RETRIES) {
+		struct tb_cfg_request *req;
+
+		req = tb_cfg_request_alloc();
+		if (!req) {
+			res.err = -ENOMEM;
+			return res;
+		}
+
+		request.addr.seq = retries++;
+
+		req->match = tb_cfg_match;
+		req->copy = tb_cfg_copy;
+		req->request = &request;
+		req->request_size = 12 + 4 * length;
+		req->request_type = TB_CFG_PKG_WRITE;
+		req->response = &reply;
+		req->response_size = sizeof(reply);
+		req->response_type = TB_CFG_PKG_WRITE;
+
+		res = tb_cfg_request_sync(ctl, req, timeout_msec);
+
+		tb_cfg_request_put(req);
+
+		if (res.err != -ETIMEDOUT)
+			break;
+
+		/* Wait a bit (arbitrary time) until we send a retry */
+		usleep_range(10, 100);
+	}
+
+	if (res.err)
+		return res;
+
+	res.response_port = reply.addr.port;
+	res.err = check_config_address(reply.addr, space, offset, length);
+	return res;
+}
+
+static int tb_cfg_get_error(struct tb_ctl *ctl, enum tb_cfg_space space,
+			    const struct tb_cfg_result *res)
+{
+	/*
+	 * For unimplemented ports access to port config space may return
+	 * TB_CFG_ERROR_INVALID_CONFIG_SPACE (alternatively their type is
+	 * set to TB_TYPE_INACTIVE). In the former case return -ENODEV so
+	 * that the caller can mark the port as disabled.
+	 */
+	if (space == TB_CFG_PORT &&
+	    res->tb_error == TB_CFG_ERROR_INVALID_CONFIG_SPACE)
+		return -ENODEV;
+
+	tb_cfg_print_error(ctl, res);
+
+	if (res->tb_error == TB_CFG_ERROR_LOCK)
+		return -EACCES;
+	else if (res->tb_error == TB_CFG_ERROR_PORT_NOT_CONNECTED)
+		return -ENOTCONN;
+
+	return -EIO;
+}
+
+int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
+		enum tb_cfg_space space, u32 offset, u32 length)
+{
+	struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
+			space, offset, length, ctl->timeout_msec);
+	switch (res.err) {
+	case 0:
+		/* Success */
+		break;
+
+	case 1:
+		/* Thunderbolt error, tb_error holds the actual number */
+		return tb_cfg_get_error(ctl, space, &res);
+
+	case -ETIMEDOUT:
+		tb_ctl_warn(ctl, "%llx: timeout reading config space %u from %#x\n",
+			    route, space, offset);
+		break;
+
+	default:
+		WARN(1, "tb_cfg_read: %d\n", res.err);
+		break;
+	}
+	return res.err;
+}
+
+int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port,
+		 enum tb_cfg_space space, u32 offset, u32 length)
+{
+	struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
+			space, offset, length, ctl->timeout_msec);
+	switch (res.err) {
+	case 0:
+		/* Success */
+		break;
+
+	case 1:
+		/* Thunderbolt error, tb_error holds the actual number */
+		return tb_cfg_get_error(ctl, space, &res);
+
+	case -ETIMEDOUT:
+		tb_ctl_warn(ctl, "%llx: timeout writing config space %u to %#x\n",
+			    route, space, offset);
+		break;
+
+	default:
+		WARN(1, "tb_cfg_write: %d\n", res.err);
+		break;
+	}
+	return res.err;
+}
+
+/**
+ * tb_cfg_get_upstream_port() - get upstream port number of switch at route
+ * @ctl: Pointer to the control channel
+ * @route: Route string of the router
+ *
+ * Reads the first dword from the switches TB_CFG_SWITCH config area and
+ * returns the port number from which the reply originated.
+ *
+ * Return: Returns the upstream port number on success or an error code on
+ * failure.
+ */
+int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
+{
+	u32 dummy;
+	struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,
+						   TB_CFG_SWITCH, 0, 1,
+						   ctl->timeout_msec);
+	if (res.err == 1)
+		return -EIO;
+	if (res.err)
+		return res.err;
+	return res.response_port;
+}