Merge branch 'linus' into x86/apic, to resolve conflicts

[mirror_ubuntu-bionic-kernel.git] / 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 = 5;
        u32 val;

        do {
                val = ioread32(nhi->iobase + REG_FW_STS);
                if (val & REG_FW_STS_NVM_AUTH_DONE)
                        break;
                msleep(30);
        } 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;

        /* 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:
                        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;
}