drivers/thunderbolt/icm.c

/*
 * Internal Thunderbolt Connection Manager. This is a firmware running on
 * the Thunderbolt host controller performing most of the low-level
 * handling.
 *
 * Copyright (C) 2017, Intel Corporation
 * Authors: Michael Jamet <michael.jamet@intel.com>
 *          Mika Westerberg <mika.westerberg@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/platform_data/x86/apple.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

#include "ctl.h"
#include "nhi_regs.h"
#include "tb.h"

#define PCIE2CIO_CMD			0x30
#define PCIE2CIO_CMD_TIMEOUT		BIT(31)
#define PCIE2CIO_CMD_START		BIT(30)
#define PCIE2CIO_CMD_WRITE		BIT(21)
#define PCIE2CIO_CMD_CS_MASK		GENMASK(20, 19)
#define PCIE2CIO_CMD_CS_SHIFT		19
#define PCIE2CIO_CMD_PORT_MASK		GENMASK(18, 13)
#define PCIE2CIO_CMD_PORT_SHIFT		13

#define PCIE2CIO_WRDATA			0x34
#define PCIE2CIO_RDDATA			0x38

#define PHY_PORT_CS1			0x37
#define PHY_PORT_CS1_LINK_DISABLE	BIT(14)
#define PHY_PORT_CS1_LINK_STATE_MASK	GENMASK(29, 26)
#define PHY_PORT_CS1_LINK_STATE_SHIFT	26

#define ICM_TIMEOUT			5000 /* ms */
#define ICM_MAX_LINK			4
#define ICM_MAX_DEPTH			6

/**
 * struct icm - Internal connection manager private data
 * @request_lock: Makes sure only one message is send to ICM at time
 * @rescan_work: Work used to rescan the surviving switches after resume
 * @upstream_port: Pointer to the PCIe upstream port this host
 *		   controller is connected. This is only set for systems
 *		   where ICM needs to be started manually
 * @vnd_cap: Vendor defined capability where PCIe2CIO mailbox resides
 *	     (only set when @upstream_port is not %NULL)
 * @safe_mode: ICM is in safe mode
 * @is_supported: Checks if we can support ICM on this controller
 * @get_mode: Read and return the ICM firmware mode (optional)
 * @get_route: Find a route string for given switch
 * @device_connected: Handle device connected ICM message
 * @device_disconnected: Handle device disconnected ICM message
 */
struct icm {
	struct mutex request_lock;
	struct delayed_work rescan_work;
	struct pci_dev *upstream_port;
	int vnd_cap;
	bool safe_mode;
	bool (*is_supported)(struct tb *tb);
	int (*get_mode)(struct tb *tb);
	int (*get_route)(struct tb *tb, u8 link, u8 depth, u64 *route);
	void (*device_connected)(struct tb *tb,
				 const struct icm_pkg_header *hdr);
	void (*device_disconnected)(struct tb *tb,
				    const struct icm_pkg_header *hdr);
};

struct icm_notification {
	struct work_struct work;
	struct icm_pkg_header *pkg;
	struct tb *tb;
};

static inline struct tb *icm_to_tb(struct icm *icm)
{
	return ((void *)icm - sizeof(struct tb));
}

static inline u8 phy_port_from_route(u64 route, u8 depth)
{
	return tb_switch_phy_port_from_link(route >> ((depth - 1) * 8));
}

static inline u8 dual_link_from_link(u8 link)
{
	return link ? ((link - 1) ^ 0x01) + 1 : 0;
}

static inline u64 get_route(u32 route_hi, u32 route_lo)
{
	return (u64)route_hi << 32 | route_lo;
}

static bool icm_match(const struct tb_cfg_request *req,
		      const struct ctl_pkg *pkg)
{
	const struct icm_pkg_header *res_hdr = pkg->buffer;
	const struct icm_pkg_header *req_hdr = req->request;

	if (pkg->frame.eof != req->response_type)
		return false;
	if (res_hdr->code != req_hdr->code)
		return false;

	return true;
}

static bool icm_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg)
{
	const struct icm_pkg_header *hdr = pkg->buffer;

	if (hdr->packet_id < req->npackets) {
		size_t offset = hdr->packet_id * req->response_size;

		memcpy(req->response + offset, pkg->buffer, req->response_size);
	}

	return hdr->packet_id == hdr->total_packets - 1;
}

static int icm_request(struct tb *tb, const void *request, size_t request_size,
		       void *response, size_t response_size, size_t npackets,
		       unsigned int timeout_msec)
{
	struct icm *icm = tb_priv(tb);
	int retries = 3;

	do {
		struct tb_cfg_request *req;
		struct tb_cfg_result res;

		req = tb_cfg_request_alloc();
		if (!req)
			return -ENOMEM;

		req->match = icm_match;
		req->copy = icm_copy;
		req->request = request;
		req->request_size = request_size;
		req->request_type = TB_CFG_PKG_ICM_CMD;
		req->response = response;
		req->npackets = npackets;
		req->response_size = response_size;
		req->response_type = TB_CFG_PKG_ICM_RESP;

		mutex_lock(&icm->request_lock);
		res = tb_cfg_request_sync(tb->ctl, req, timeout_msec);
		mutex_unlock(&icm->request_lock);

		tb_cfg_request_put(req);

		if (res.err != -ETIMEDOUT)
			return res.err == 1 ? -EIO : res.err;

		usleep_range(20, 50);
	} while (retries--);

	return -ETIMEDOUT;
}

static bool icm_fr_is_supported(struct tb *tb)
{
	return !x86_apple_machine;
}

static inline int icm_fr_get_switch_index(u32 port)
{
	int index;

	if ((port & ICM_PORT_TYPE_MASK) != TB_TYPE_PORT)
		return 0;

	index = port >> ICM_PORT_INDEX_SHIFT;
	return index != 0xff ? index : 0;
}

static int icm_fr_get_route(struct tb *tb, u8 link, u8 depth, u64 *route)
{
	struct icm_fr_pkg_get_topology_response *switches, *sw;
	struct icm_fr_pkg_get_topology request = {
		.hdr = { .code = ICM_GET_TOPOLOGY },
	};
	size_t npackets = ICM_GET_TOPOLOGY_PACKETS;
	int ret, index;
	u8 i;

	switches = kcalloc(npackets, sizeof(*switches), GFP_KERNEL);
	if (!switches)
		return -ENOMEM;

	ret = icm_request(tb, &request, sizeof(request), switches,
			  sizeof(*switches), npackets, ICM_TIMEOUT);
	if (ret)
		goto err_free;

	sw = &switches[0];
	index = icm_fr_get_switch_index(sw->ports[link]);
	if (!index) {
		ret = -ENODEV;
		goto err_free;
	}

	sw = &switches[index];
	for (i = 1; i < depth; i++) {
		unsigned int j;

		if (!(sw->first_data & ICM_SWITCH_USED)) {
			ret = -ENODEV;
			goto err_free;
		}

		for (j = 0; j < ARRAY_SIZE(sw->ports); j++) {
			index = icm_fr_get_switch_index(sw->ports[j]);
			if (index > sw->switch_index) {
				sw = &switches[index];
				break;
			}
		}
	}

	*route = get_route(sw->route_hi, sw->route_lo);

err_free:
	kfree(switches);
	return ret;
}

static int icm_fr_approve_switch(struct tb *tb, struct tb_switch *sw)
{
	struct icm_fr_pkg_approve_device request;
	struct icm_fr_pkg_approve_device reply;
	int ret;

	memset(&request, 0, sizeof(request));
	memcpy(&request.ep_uuid, sw->uuid, sizeof(request.ep_uuid));
	request.hdr.code = ICM_APPROVE_DEVICE;
	request.connection_id = sw->connection_id;
	request.connection_key = sw->connection_key;

	memset(&reply, 0, sizeof(reply));
	/* Use larger timeout as establishing tunnels can take some time */
	ret = icm_request(tb, &request, sizeof(request), &reply, sizeof(reply),
			  1, 10000);
	if (ret)
		return ret;

	if (reply.hdr.flags & ICM_FLAGS_ERROR) {
		tb_warn(tb, "PCIe tunnel creation failed\n");
		return -EIO;
	}

	return 0;
}

static int icm_fr_add_switch_key(struct tb *tb, struct tb_switch *sw)
{
	struct icm_fr_pkg_add_device_key request;
	struct icm_fr_pkg_add_device_key_response reply;
	int ret;

	memset(&request, 0, sizeof(request));
	memcpy(&request.ep_uuid, sw->uuid, sizeof(request.ep_uuid));
	request.hdr.code = ICM_ADD_DEVICE_KEY;
	request.connection_id = sw->connection_id;
	request.connection_key = sw->connection_key;
	memcpy(request.key, sw->key, TB_SWITCH_KEY_SIZE);

	memset(&reply, 0, sizeof(reply));
	ret = icm_request(tb, &request, sizeof(request), &reply, sizeof(reply),
			  1, ICM_TIMEOUT);
	if (ret)
		return ret;

	if (reply.hdr.flags & ICM_FLAGS_ERROR) {
		tb_warn(tb, "Adding key to switch failed\n");
		return -EIO;
	}

	return 0;
}

static int icm_fr_challenge_switch_key(struct tb *tb, struct tb_switch *sw,
				       const u8 *challenge, u8 *response)
{
	struct icm_fr_pkg_challenge_device request;
	struct icm_fr_pkg_challenge_device_response reply;
	int ret;

	memset(&request, 0, sizeof(request));
	memcpy(&request.ep_uuid, sw->uuid, sizeof(request.ep_uuid));
	request.hdr.code = ICM_CHALLENGE_DEVICE;
	request.connection_id = sw->connection_id;
	request.connection_key = sw->connection_key;
	memcpy(request.challenge, challenge, TB_SWITCH_KEY_SIZE);

	memset(&reply, 0, sizeof(reply));
	ret = icm_request(tb, &request, sizeof(request), &reply, sizeof(reply),
			  1, ICM_TIMEOUT);
	if (ret)
		return ret;

	if (reply.hdr.flags & ICM_FLAGS_ERROR)
		return -EKEYREJECTED;
	if (reply.hdr.flags & ICM_FLAGS_NO_KEY)
		return -ENOKEY;

	memcpy(response, reply.response, TB_SWITCH_KEY_SIZE);

	return 0;
}

static void remove_switch(struct tb_switch *sw)
{
	struct tb_switch *parent_sw;

	parent_sw = tb_to_switch(sw->dev.parent);
	tb_port_at(tb_route(sw), parent_sw)->remote = NULL;
	tb_switch_remove(sw);
}

static void
icm_fr_device_connected(struct tb *tb, const struct icm_pkg_header *hdr)
{
	const struct icm_fr_event_device_connected *pkg =
		(const struct icm_fr_event_device_connected *)hdr;
	struct tb_switch *sw, *parent_sw;
	struct icm *icm = tb_priv(tb);
	bool authorized = false;
	u8 link, depth;
	u64 route;
	int ret;

	link = pkg->link_info & ICM_LINK_INFO_LINK_MASK;
	depth = (pkg->link_info & ICM_LINK_INFO_DEPTH_MASK) >>
		ICM_LINK_INFO_DEPTH_SHIFT;
	authorized = pkg->link_info & ICM_LINK_INFO_APPROVED;

	ret = icm->get_route(tb, link, depth, &route);
	if (ret) {
		tb_err(tb, "failed to find route string for switch at %u.%u\n",
		       link, depth);
		return;
	}

	sw = tb_switch_find_by_uuid(tb, &pkg->ep_uuid);
	if (sw) {
		u8 phy_port, sw_phy_port;

		parent_sw = tb_to_switch(sw->dev.parent);
		sw_phy_port = phy_port_from_route(tb_route(sw), sw->depth);
		phy_port = phy_port_from_route(route, depth);

		/*
		 * On resume ICM will send us connected events for the
		 * devices that still are present. However, that
		 * information might have changed for example by the
		 * fact that a switch on a dual-link connection might
		 * have been enumerated using the other link now. Make
		 * sure our book keeping matches that.
		 */
		if (sw->depth == depth && sw_phy_port == phy_port &&
		    !!sw->authorized == authorized) {
			tb_port_at(tb_route(sw), parent_sw)->remote = NULL;
			tb_port_at(route, parent_sw)->remote =
				   tb_upstream_port(sw);
			sw->config.route_hi = upper_32_bits(route);
			sw->config.route_lo = lower_32_bits(route);
			sw->connection_id = pkg->connection_id;
			sw->connection_key = pkg->connection_key;
			sw->link = link;
			sw->depth = depth;
			sw->is_unplugged = false;
			tb_switch_put(sw);
			return;
		}

		/*
		 * User connected the same switch to another physical
		 * port or to another part of the topology. Remove the
		 * existing switch now before adding the new one.
		 */
		remove_switch(sw);
		tb_switch_put(sw);
	}

	/*
	 * If the switch was not found by UUID, look for a switch on
	 * same physical port (taking possible link aggregation into
	 * account) and depth. If we found one it is definitely a stale
	 * one so remove it first.
	 */
	sw = tb_switch_find_by_link_depth(tb, link, depth);
	if (!sw) {
		u8 dual_link;

		dual_link = dual_link_from_link(link);
		if (dual_link)
			sw = tb_switch_find_by_link_depth(tb, dual_link, depth);
	}
	if (sw) {
		remove_switch(sw);
		tb_switch_put(sw);
	}

	parent_sw = tb_switch_find_by_link_depth(tb, link, depth - 1);
	if (!parent_sw) {
		tb_err(tb, "failed to find parent switch for %u.%u\n",
		       link, depth);
		return;
	}

	sw = tb_switch_alloc(tb, &parent_sw->dev, route);
	if (!sw) {
		tb_switch_put(parent_sw);
		return;
	}

	sw->uuid = kmemdup(&pkg->ep_uuid, sizeof(pkg->ep_uuid), GFP_KERNEL);
	sw->connection_id = pkg->connection_id;
	sw->connection_key = pkg->connection_key;
	sw->link = link;
	sw->depth = depth;
	sw->authorized = authorized;
	sw->security_level = (pkg->hdr.flags & ICM_FLAGS_SLEVEL_MASK) >>
				ICM_FLAGS_SLEVEL_SHIFT;

	/* Link the two switches now */
	tb_port_at(route, parent_sw)->remote = tb_upstream_port(sw);
	tb_upstream_port(sw)->remote = tb_port_at(route, parent_sw);

	ret = tb_switch_add(sw);
	if (ret) {
		tb_port_at(tb_route(sw), parent_sw)->remote = NULL;
		tb_switch_put(sw);
	}
	tb_switch_put(parent_sw);
}

static void
icm_fr_device_disconnected(struct tb *tb, const struct icm_pkg_header *hdr)
{
	const struct icm_fr_event_device_disconnected *pkg =
		(const struct icm_fr_event_device_disconnected *)hdr;
	struct tb_switch *sw;
	u8 link, depth;

	link = pkg->link_info & ICM_LINK_INFO_LINK_MASK;
	depth = (pkg->link_info & ICM_LINK_INFO_DEPTH_MASK) >>
		ICM_LINK_INFO_DEPTH_SHIFT;

	if (link > ICM_MAX_LINK || depth > ICM_MAX_DEPTH) {
		tb_warn(tb, "invalid topology %u.%u, ignoring\n", link, depth);
		return;
	}

	sw = tb_switch_find_by_link_depth(tb, link, depth);
	if (!sw) {
		tb_warn(tb, "no switch exists at %u.%u, ignoring\n", link,
			depth);
		return;
	}

	remove_switch(sw);
	tb_switch_put(sw);
}

static struct pci_dev *get_upstream_port(struct pci_dev *pdev)
{
	struct pci_dev *parent;

	parent = pci_upstream_bridge(pdev);
	while (parent) {
		if (!pci_is_pcie(parent))
			return NULL;
		if (pci_pcie_type(parent) == PCI_EXP_TYPE_UPSTREAM)
			break;
		parent = pci_upstream_bridge(parent);
	}

	if (!parent)
		return NULL;

	switch (parent->device) {
	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_BRIDGE:
	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_BRIDGE:
	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_BRIDGE:
	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_BRIDGE:
	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_BRIDGE:
		return parent;
	}

	return NULL;
}

static bool icm_ar_is_supported(struct tb *tb)
{
	struct pci_dev *upstream_port;
	struct icm *icm = tb_priv(tb);

	/*
	 * Starting from Alpine Ridge we can use ICM on Apple machines
	 * as well. We just need to reset and re-enable it first.
	 */
	if (!x86_apple_machine)
		return true;

	/*
	 * Find the upstream PCIe port in case we need to do reset
	 * through its vendor specific registers.
	 */
	upstream_port = get_upstream_port(tb->nhi->pdev);
	if (upstream_port) {
		int cap;

		cap = pci_find_ext_capability(upstream_port,
					      PCI_EXT_CAP_ID_VNDR);
		if (cap > 0) {
			icm->upstream_port = upstream_port;
			icm->vnd_cap = cap;

			return true;
		}
	}

	return false;
}

static int icm_ar_get_mode(struct tb *tb)
{
	struct tb_nhi *nhi = tb->nhi;
	int retries = 60;
	u32 val;

	do {
		val = ioread32(nhi->iobase + REG_FW_STS);
		if (val & REG_FW_STS_NVM_AUTH_DONE)
			break;
		msleep(50);
	} while (--retries);

	if (!retries) {
		dev_err(&nhi->pdev->dev, "ICM firmware not authenticated\n");
		return -ENODEV;
	}

	return nhi_mailbox_mode(nhi);
}

static int icm_ar_get_route(struct tb *tb, u8 link, u8 depth, u64 *route)
{
	struct icm_ar_pkg_get_route_response reply;
	struct icm_ar_pkg_get_route request = {
		.hdr = { .code = ICM_GET_ROUTE },
		.link_info = depth << ICM_LINK_INFO_DEPTH_SHIFT | link,
	};
	int ret;

	memset(&reply, 0, sizeof(reply));
	ret = icm_request(tb, &request, sizeof(request), &reply, sizeof(reply),
			  1, ICM_TIMEOUT);
	if (ret)
		return ret;

	if (reply.hdr.flags & ICM_FLAGS_ERROR)
		return -EIO;

	*route = get_route(reply.route_hi, reply.route_lo);
	return 0;
}

static void icm_handle_notification(struct work_struct *work)
{
	struct icm_notification *n = container_of(work, typeof(*n), work);
	struct tb *tb = n->tb;
	struct icm *icm = tb_priv(tb);

	mutex_lock(&tb->lock);

	switch (n->pkg->code) {
	case ICM_EVENT_DEVICE_CONNECTED:
		icm->device_connected(tb, n->pkg);
		break;
	case ICM_EVENT_DEVICE_DISCONNECTED:
		icm->device_disconnected(tb, n->pkg);
		break;
	}

	mutex_unlock(&tb->lock);

	kfree(n->pkg);
	kfree(n);
}

static void icm_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
			     const void *buf, size_t size)
{
	struct icm_notification *n;

	n = kmalloc(sizeof(*n), GFP_KERNEL);
	if (!n)
		return;

	INIT_WORK(&n->work, icm_handle_notification);
	n->pkg = kmemdup(buf, size, GFP_KERNEL);
	n->tb = tb;

	queue_work(tb->wq, &n->work);
}

static int
__icm_driver_ready(struct tb *tb, enum tb_security_level *security_level)
{
	struct icm_pkg_driver_ready_response reply;
	struct icm_pkg_driver_ready request = {
		.hdr.code = ICM_DRIVER_READY,
	};
	unsigned int retries = 10;
	int ret;

	memset(&reply, 0, sizeof(reply));
	ret = icm_request(tb, &request, sizeof(request), &reply, sizeof(reply),
			  1, ICM_TIMEOUT);
	if (ret)
		return ret;

	if (security_level)
		*security_level = reply.security_level & 0xf;

	/*
	 * Hold on here until the switch config space is accessible so
	 * that we can read root switch config successfully.
	 */
	do {
		struct tb_cfg_result res;
		u32 tmp;

		res = tb_cfg_read_raw(tb->ctl, &tmp, 0, 0, TB_CFG_SWITCH,
				      0, 1, 100);
		if (!res.err)
			return 0;

		msleep(50);
	} while (--retries);

	return -ETIMEDOUT;
}

static int pci2cio_wait_completion(struct icm *icm, unsigned long timeout_msec)
{
	unsigned long end = jiffies + msecs_to_jiffies(timeout_msec);
	u32 cmd;

	do {
		pci_read_config_dword(icm->upstream_port,
				      icm->vnd_cap + PCIE2CIO_CMD, &cmd);
		if (!(cmd & PCIE2CIO_CMD_START)) {
			if (cmd & PCIE2CIO_CMD_TIMEOUT)
				break;
			return 0;
		}

		msleep(50);
	} while (time_before(jiffies, end));

	return -ETIMEDOUT;
}

static int pcie2cio_read(struct icm *icm, enum tb_cfg_space cs,
			 unsigned int port, unsigned int index, u32 *data)
{
	struct pci_dev *pdev = icm->upstream_port;
	int ret, vnd_cap = icm->vnd_cap;
	u32 cmd;

	cmd = index;
	cmd |= (port << PCIE2CIO_CMD_PORT_SHIFT) & PCIE2CIO_CMD_PORT_MASK;
	cmd |= (cs << PCIE2CIO_CMD_CS_SHIFT) & PCIE2CIO_CMD_CS_MASK;
	cmd |= PCIE2CIO_CMD_START;
	pci_write_config_dword(pdev, vnd_cap + PCIE2CIO_CMD, cmd);

	ret = pci2cio_wait_completion(icm, 5000);
	if (ret)
		return ret;

	pci_read_config_dword(pdev, vnd_cap + PCIE2CIO_RDDATA, data);
	return 0;
}

static int pcie2cio_write(struct icm *icm, enum tb_cfg_space cs,
			  unsigned int port, unsigned int index, u32 data)
{
	struct pci_dev *pdev = icm->upstream_port;
	int vnd_cap = icm->vnd_cap;
	u32 cmd;

	pci_write_config_dword(pdev, vnd_cap + PCIE2CIO_WRDATA, data);

	cmd = index;
	cmd |= (port << PCIE2CIO_CMD_PORT_SHIFT) & PCIE2CIO_CMD_PORT_MASK;
	cmd |= (cs << PCIE2CIO_CMD_CS_SHIFT) & PCIE2CIO_CMD_CS_MASK;
	cmd |= PCIE2CIO_CMD_WRITE | PCIE2CIO_CMD_START;
	pci_write_config_dword(pdev, vnd_cap + PCIE2CIO_CMD, cmd);

	return pci2cio_wait_completion(icm, 5000);
}

static int icm_firmware_reset(struct tb *tb, struct tb_nhi *nhi)
{
	struct icm *icm = tb_priv(tb);
	u32 val;

	if (!icm->upstream_port)
		return -ENODEV;

	/* Put ARC to wait for CIO reset event to happen */
	val = ioread32(nhi->iobase + REG_FW_STS);
	val |= REG_FW_STS_CIO_RESET_REQ;
	iowrite32(val, nhi->iobase + REG_FW_STS);

	/* Re-start ARC */
	val = ioread32(nhi->iobase + REG_FW_STS);
	val |= REG_FW_STS_ICM_EN_INVERT;
	val |= REG_FW_STS_ICM_EN_CPU;
	iowrite32(val, nhi->iobase + REG_FW_STS);

	/* Trigger CIO reset now */
	return pcie2cio_write(icm, TB_CFG_SWITCH, 0, 0x50, BIT(9));
}

static int icm_firmware_start(struct tb *tb, struct tb_nhi *nhi)
{
	unsigned int retries = 10;
	int ret;
	u32 val;

	/* Check if the ICM firmware is already running */
	val = ioread32(nhi->iobase + REG_FW_STS);
	if (val & REG_FW_STS_ICM_EN)
		return 0;

	dev_info(&nhi->pdev->dev, "starting ICM firmware\n");

	ret = icm_firmware_reset(tb, nhi);
	if (ret)
		return ret;

	/* Wait until the ICM firmware tells us it is up and running */
	do {
		/* Check that the ICM firmware is running */
		val = ioread32(nhi->iobase + REG_FW_STS);
		if (val & REG_FW_STS_NVM_AUTH_DONE)
			return 0;

		msleep(300);
	} while (--retries);

	return -ETIMEDOUT;
}

static int icm_reset_phy_port(struct tb *tb, int phy_port)
{
	struct icm *icm = tb_priv(tb);
	u32 state0, state1;
	int port0, port1;
	u32 val0, val1;
	int ret;

	if (!icm->upstream_port)
		return 0;

	if (phy_port) {
		port0 = 3;
		port1 = 4;
	} else {
		port0 = 1;
		port1 = 2;
	}

	/*
	 * Read link status of both null ports belonging to a single
	 * physical port.
	 */
	ret = pcie2cio_read(icm, TB_CFG_PORT, port0, PHY_PORT_CS1, &val0);
	if (ret)
		return ret;
	ret = pcie2cio_read(icm, TB_CFG_PORT, port1, PHY_PORT_CS1, &val1);
	if (ret)
		return ret;

	state0 = val0 & PHY_PORT_CS1_LINK_STATE_MASK;
	state0 >>= PHY_PORT_CS1_LINK_STATE_SHIFT;
	state1 = val1 & PHY_PORT_CS1_LINK_STATE_MASK;
	state1 >>= PHY_PORT_CS1_LINK_STATE_SHIFT;

	/* If they are both up we need to reset them now */
	if (state0 != TB_PORT_UP || state1 != TB_PORT_UP)
		return 0;

	val0 |= PHY_PORT_CS1_LINK_DISABLE;
	ret = pcie2cio_write(icm, TB_CFG_PORT, port0, PHY_PORT_CS1, val0);
	if (ret)
		return ret;

	val1 |= PHY_PORT_CS1_LINK_DISABLE;
	ret = pcie2cio_write(icm, TB_CFG_PORT, port1, PHY_PORT_CS1, val1);
	if (ret)
		return ret;

	/* Wait a bit and then re-enable both ports */
	usleep_range(10, 100);

	ret = pcie2cio_read(icm, TB_CFG_PORT, port0, PHY_PORT_CS1, &val0);
	if (ret)
		return ret;
	ret = pcie2cio_read(icm, TB_CFG_PORT, port1, PHY_PORT_CS1, &val1);
	if (ret)
		return ret;

	val0 &= ~PHY_PORT_CS1_LINK_DISABLE;
	ret = pcie2cio_write(icm, TB_CFG_PORT, port0, PHY_PORT_CS1, val0);
	if (ret)
		return ret;

	val1 &= ~PHY_PORT_CS1_LINK_DISABLE;
	return pcie2cio_write(icm, TB_CFG_PORT, port1, PHY_PORT_CS1, val1);
}

static int icm_firmware_init(struct tb *tb)
{
	struct icm *icm = tb_priv(tb);
	struct tb_nhi *nhi = tb->nhi;
	int ret;

	ret = icm_firmware_start(tb, nhi);
	if (ret) {
		dev_err(&nhi->pdev->dev, "could not start ICM firmware\n");
		return ret;
	}

	if (icm->get_mode) {
		ret = icm->get_mode(tb);

		switch (ret) {
		case NHI_FW_SAFE_MODE:
			icm->safe_mode = true;
			break;

		case NHI_FW_CM_MODE:
			/* Ask ICM to accept all Thunderbolt devices */
			nhi_mailbox_cmd(nhi, NHI_MAILBOX_ALLOW_ALL_DEVS, 0);
			break;

		default:
			if (ret < 0)
				return ret;

			tb_err(tb, "ICM firmware is in wrong mode: %u\n", ret);
			return -ENODEV;
		}
	}

	/*
	 * Reset both physical ports if there is anything connected to
	 * them already.
	 */
	ret = icm_reset_phy_port(tb, 0);
	if (ret)
		dev_warn(&nhi->pdev->dev, "failed to reset links on port0\n");
	ret = icm_reset_phy_port(tb, 1);
	if (ret)
		dev_warn(&nhi->pdev->dev, "failed to reset links on port1\n");

	return 0;
}

static int icm_driver_ready(struct tb *tb)
{
	struct icm *icm = tb_priv(tb);
	int ret;

	ret = icm_firmware_init(tb);
	if (ret)
		return ret;

	if (icm->safe_mode) {
		tb_info(tb, "Thunderbolt host controller is in safe mode.\n");
		tb_info(tb, "You need to update NVM firmware of the controller before it can be used.\n");
		tb_info(tb, "For latest updates check https://thunderbolttechnology.net/updates.\n");
		return 0;
	}

	return __icm_driver_ready(tb, &tb->security_level);
}

static int icm_suspend(struct tb *tb)
{
	int ret;

	ret = nhi_mailbox_cmd(tb->nhi, NHI_MAILBOX_SAVE_DEVS, 0);
	if (ret)
		tb_info(tb, "Ignoring mailbox command error (%d) in %s\n",
			ret, __func__);

	return 0;
}

/*
 * Mark all switches (except root switch) below this one unplugged. ICM
 * firmware will send us an updated list of switches after we have send
 * it driver ready command. If a switch is not in that list it will be
 * removed when we perform rescan.
 */
static void icm_unplug_children(struct tb_switch *sw)
{
	unsigned int i;

	if (tb_route(sw))
		sw->is_unplugged = true;

	for (i = 1; i <= sw->config.max_port_number; i++) {
		struct tb_port *port = &sw->ports[i];

		if (tb_is_upstream_port(port))
			continue;
		if (!port->remote)
			continue;

		icm_unplug_children(port->remote->sw);
	}
}

static void icm_free_unplugged_children(struct tb_switch *sw)
{
	unsigned int i;

	for (i = 1; i <= sw->config.max_port_number; i++) {
		struct tb_port *port = &sw->ports[i];

		if (tb_is_upstream_port(port))
			continue;
		if (!port->remote)
			continue;

		if (port->remote->sw->is_unplugged) {
			tb_switch_remove(port->remote->sw);
			port->remote = NULL;
		} else {
			icm_free_unplugged_children(port->remote->sw);
		}
	}
}

static void icm_rescan_work(struct work_struct *work)
{
	struct icm *icm = container_of(work, struct icm, rescan_work.work);
	struct tb *tb = icm_to_tb(icm);

	mutex_lock(&tb->lock);
	if (tb->root_switch)
		icm_free_unplugged_children(tb->root_switch);
	mutex_unlock(&tb->lock);
}

static void icm_complete(struct tb *tb)
{
	struct icm *icm = tb_priv(tb);

	if (tb->nhi->going_away)
		return;

	icm_unplug_children(tb->root_switch);

	/*
	 * Now all existing children should be resumed, start events
	 * from ICM to get updated status.
	 */
	__icm_driver_ready(tb, NULL);

	/*
	 * We do not get notifications of devices that have been
	 * unplugged during suspend so schedule rescan to clean them up
	 * if any.
	 */
	queue_delayed_work(tb->wq, &icm->rescan_work, msecs_to_jiffies(500));
}

static int icm_start(struct tb *tb)
{
	struct icm *icm = tb_priv(tb);
	int ret;

	if (icm->safe_mode)
		tb->root_switch = tb_switch_alloc_safe_mode(tb, &tb->dev, 0);
	else
		tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
	if (!tb->root_switch)
		return -ENODEV;

	/*
	 * NVM upgrade has not been tested on Apple systems and they
	 * don't provide images publicly either. To be on the safe side
	 * prevent root switch NVM upgrade on Macs for now.
	 */
	tb->root_switch->no_nvm_upgrade = x86_apple_machine;

	ret = tb_switch_add(tb->root_switch);
	if (ret)
		tb_switch_put(tb->root_switch);

	return ret;
}

static void icm_stop(struct tb *tb)
{
	struct icm *icm = tb_priv(tb);

	cancel_delayed_work(&icm->rescan_work);
	tb_switch_remove(tb->root_switch);
	tb->root_switch = NULL;
	nhi_mailbox_cmd(tb->nhi, NHI_MAILBOX_DRV_UNLOADS, 0);
}

static int icm_disconnect_pcie_paths(struct tb *tb)
{
	return nhi_mailbox_cmd(tb->nhi, NHI_MAILBOX_DISCONNECT_PCIE_PATHS, 0);
}

/* Falcon Ridge and Alpine Ridge */
static const struct tb_cm_ops icm_fr_ops = {
	.driver_ready = icm_driver_ready,
	.start = icm_start,
	.stop = icm_stop,
	.suspend = icm_suspend,
	.complete = icm_complete,
	.handle_event = icm_handle_event,
	.approve_switch = icm_fr_approve_switch,
	.add_switch_key = icm_fr_add_switch_key,
	.challenge_switch_key = icm_fr_challenge_switch_key,
	.disconnect_pcie_paths = icm_disconnect_pcie_paths,
};

struct tb *icm_probe(struct tb_nhi *nhi)
{
	struct icm *icm;
	struct tb *tb;

	tb = tb_domain_alloc(nhi, sizeof(struct icm));
	if (!tb)
		return NULL;

	icm = tb_priv(tb);
	INIT_DELAYED_WORK(&icm->rescan_work, icm_rescan_work);
	mutex_init(&icm->request_lock);

	switch (nhi->pdev->device) {
	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI:
	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI:
		icm->is_supported = icm_fr_is_supported;
		icm->get_route = icm_fr_get_route;
		icm->device_connected = icm_fr_device_connected;
		icm->device_disconnected = icm_fr_device_disconnected;
		tb->cm_ops = &icm_fr_ops;
		break;

	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_NHI:
	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_NHI:
	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_NHI:
	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_NHI:
	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_NHI:
		icm->is_supported = icm_ar_is_supported;
		icm->get_mode = icm_ar_get_mode;
		icm->get_route = icm_ar_get_route;
		icm->device_connected = icm_fr_device_connected;
		icm->device_disconnected = icm_fr_device_disconnected;
		tb->cm_ops = &icm_fr_ops;
		break;
	}

	if (!icm->is_supported || !icm->is_supported(tb)) {
		dev_dbg(&nhi->pdev->dev, "ICM not supported on this controller\n");
		tb_domain_put(tb);
		return NULL;
	}

	return tb;
}