summaryrefslogtreecommitdiffstats
path: root/drivers/thunderbolt/tunnel.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/thunderbolt/tunnel.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/thunderbolt/tunnel.c')
-rw-r--r--drivers/thunderbolt/tunnel.c2389
1 files changed, 2389 insertions, 0 deletions
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
new file mode 100644
index 0000000000..a6810fb368
--- /dev/null
+++ b/drivers/thunderbolt/tunnel.c
@@ -0,0 +1,2389 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt driver - Tunneling support
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ * Copyright (C) 2019, Intel Corporation
+ */
+
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/ktime.h>
+#include <linux/string_helpers.h>
+
+#include "tunnel.h"
+#include "tb.h"
+
+/* PCIe adapters use always HopID of 8 for both directions */
+#define TB_PCI_HOPID 8
+
+#define TB_PCI_PATH_DOWN 0
+#define TB_PCI_PATH_UP 1
+
+/* USB3 adapters use always HopID of 8 for both directions */
+#define TB_USB3_HOPID 8
+
+#define TB_USB3_PATH_DOWN 0
+#define TB_USB3_PATH_UP 1
+
+/* DP adapters use HopID 8 for AUX and 9 for Video */
+#define TB_DP_AUX_TX_HOPID 8
+#define TB_DP_AUX_RX_HOPID 8
+#define TB_DP_VIDEO_HOPID 9
+
+#define TB_DP_VIDEO_PATH_OUT 0
+#define TB_DP_AUX_PATH_OUT 1
+#define TB_DP_AUX_PATH_IN 2
+
+/* Minimum number of credits needed for PCIe path */
+#define TB_MIN_PCIE_CREDITS 6U
+/*
+ * Number of credits we try to allocate for each DMA path if not limited
+ * by the host router baMaxHI.
+ */
+#define TB_DMA_CREDITS 14
+/* Minimum number of credits for DMA path */
+#define TB_MIN_DMA_CREDITS 1
+
+static unsigned int dma_credits = TB_DMA_CREDITS;
+module_param(dma_credits, uint, 0444);
+MODULE_PARM_DESC(dma_credits, "specify custom credits for DMA tunnels (default: "
+ __MODULE_STRING(TB_DMA_CREDITS) ")");
+
+static bool bw_alloc_mode = true;
+module_param(bw_alloc_mode, bool, 0444);
+MODULE_PARM_DESC(bw_alloc_mode,
+ "enable bandwidth allocation mode if supported (default: true)");
+
+static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
+
+#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...) \
+ do { \
+ struct tb_tunnel *__tunnel = (tunnel); \
+ level(__tunnel->tb, "%llx:%u <-> %llx:%u (%s): " fmt, \
+ tb_route(__tunnel->src_port->sw), \
+ __tunnel->src_port->port, \
+ tb_route(__tunnel->dst_port->sw), \
+ __tunnel->dst_port->port, \
+ tb_tunnel_names[__tunnel->type], \
+ ## arg); \
+ } while (0)
+
+#define tb_tunnel_WARN(tunnel, fmt, arg...) \
+ __TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
+#define tb_tunnel_warn(tunnel, fmt, arg...) \
+ __TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
+#define tb_tunnel_info(tunnel, fmt, arg...) \
+ __TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
+#define tb_tunnel_dbg(tunnel, fmt, arg...) \
+ __TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
+
+static inline unsigned int tb_usable_credits(const struct tb_port *port)
+{
+ return port->total_credits - port->ctl_credits;
+}
+
+/**
+ * tb_available_credits() - Available credits for PCIe and DMA
+ * @port: Lane adapter to check
+ * @max_dp_streams: If non-%NULL stores maximum number of simultaneous DP
+ * streams possible through this lane adapter
+ */
+static unsigned int tb_available_credits(const struct tb_port *port,
+ size_t *max_dp_streams)
+{
+ const struct tb_switch *sw = port->sw;
+ int credits, usb3, pcie, spare;
+ size_t ndp;
+
+ usb3 = tb_acpi_may_tunnel_usb3() ? sw->max_usb3_credits : 0;
+ pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0;
+
+ if (tb_acpi_is_xdomain_allowed()) {
+ spare = min_not_zero(sw->max_dma_credits, dma_credits);
+ /* Add some credits for potential second DMA tunnel */
+ spare += TB_MIN_DMA_CREDITS;
+ } else {
+ spare = 0;
+ }
+
+ credits = tb_usable_credits(port);
+ if (tb_acpi_may_tunnel_dp()) {
+ /*
+ * Maximum number of DP streams possible through the
+ * lane adapter.
+ */
+ if (sw->min_dp_aux_credits + sw->min_dp_main_credits)
+ ndp = (credits - (usb3 + pcie + spare)) /
+ (sw->min_dp_aux_credits + sw->min_dp_main_credits);
+ else
+ ndp = 0;
+ } else {
+ ndp = 0;
+ }
+ credits -= ndp * (sw->min_dp_aux_credits + sw->min_dp_main_credits);
+ credits -= usb3;
+
+ if (max_dp_streams)
+ *max_dp_streams = ndp;
+
+ return credits > 0 ? credits : 0;
+}
+
+static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
+ enum tb_tunnel_type type)
+{
+ struct tb_tunnel *tunnel;
+
+ tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
+ if (!tunnel)
+ return NULL;
+
+ tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
+ if (!tunnel->paths) {
+ tb_tunnel_free(tunnel);
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&tunnel->list);
+ tunnel->tb = tb;
+ tunnel->npaths = npaths;
+ tunnel->type = type;
+
+ return tunnel;
+}
+
+static int tb_pci_set_ext_encapsulation(struct tb_tunnel *tunnel, bool enable)
+{
+ int ret;
+
+ /* Only supported of both routers are at least USB4 v2 */
+ if (usb4_switch_version(tunnel->src_port->sw) < 2 ||
+ usb4_switch_version(tunnel->dst_port->sw) < 2)
+ return 0;
+
+ ret = usb4_pci_port_set_ext_encapsulation(tunnel->src_port, enable);
+ if (ret)
+ return ret;
+
+ ret = usb4_pci_port_set_ext_encapsulation(tunnel->dst_port, enable);
+ if (ret)
+ return ret;
+
+ tb_tunnel_dbg(tunnel, "extended encapsulation %s\n",
+ str_enabled_disabled(enable));
+ return 0;
+}
+
+static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
+{
+ int res;
+
+ if (activate) {
+ res = tb_pci_set_ext_encapsulation(tunnel, activate);
+ if (res)
+ return res;
+ }
+
+ res = tb_pci_port_enable(tunnel->src_port, activate);
+ if (res)
+ return res;
+
+ if (tb_port_is_pcie_up(tunnel->dst_port)) {
+ res = tb_pci_port_enable(tunnel->dst_port, activate);
+ if (res)
+ return res;
+ }
+
+ return activate ? 0 : tb_pci_set_ext_encapsulation(tunnel, activate);
+}
+
+static int tb_pci_init_credits(struct tb_path_hop *hop)
+{
+ struct tb_port *port = hop->in_port;
+ struct tb_switch *sw = port->sw;
+ unsigned int credits;
+
+ if (tb_port_use_credit_allocation(port)) {
+ unsigned int available;
+
+ available = tb_available_credits(port, NULL);
+ credits = min(sw->max_pcie_credits, available);
+
+ if (credits < TB_MIN_PCIE_CREDITS)
+ return -ENOSPC;
+
+ credits = max(TB_MIN_PCIE_CREDITS, credits);
+ } else {
+ if (tb_port_is_null(port))
+ credits = port->bonded ? 32 : 16;
+ else
+ credits = 7;
+ }
+
+ hop->initial_credits = credits;
+ return 0;
+}
+
+static int tb_pci_init_path(struct tb_path *path)
+{
+ struct tb_path_hop *hop;
+
+ path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
+ path->egress_shared_buffer = TB_PATH_NONE;
+ path->ingress_fc_enable = TB_PATH_ALL;
+ path->ingress_shared_buffer = TB_PATH_NONE;
+ path->priority = 3;
+ path->weight = 1;
+ path->drop_packages = 0;
+
+ tb_path_for_each_hop(path, hop) {
+ int ret;
+
+ ret = tb_pci_init_credits(hop);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
+ * @tb: Pointer to the domain structure
+ * @down: PCIe downstream adapter
+ * @alloc_hopid: Allocate HopIDs from visited ports
+ *
+ * If @down adapter is active, follows the tunnel to the PCIe upstream
+ * adapter and back. Returns the discovered tunnel or %NULL if there was
+ * no tunnel.
+ */
+struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,
+ bool alloc_hopid)
+{
+ struct tb_tunnel *tunnel;
+ struct tb_path *path;
+
+ if (!tb_pci_port_is_enabled(down))
+ return NULL;
+
+ tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
+ if (!tunnel)
+ return NULL;
+
+ tunnel->activate = tb_pci_activate;
+ tunnel->src_port = down;
+
+ /*
+ * Discover both paths even if they are not complete. We will
+ * clean them up by calling tb_tunnel_deactivate() below in that
+ * case.
+ */
+ path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
+ &tunnel->dst_port, "PCIe Up", alloc_hopid);
+ if (!path) {
+ /* Just disable the downstream port */
+ tb_pci_port_enable(down, false);
+ goto err_free;
+ }
+ tunnel->paths[TB_PCI_PATH_UP] = path;
+ if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]))
+ goto err_free;
+
+ path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
+ "PCIe Down", alloc_hopid);
+ if (!path)
+ goto err_deactivate;
+ tunnel->paths[TB_PCI_PATH_DOWN] = path;
+ if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]))
+ goto err_deactivate;
+
+ /* Validate that the tunnel is complete */
+ if (!tb_port_is_pcie_up(tunnel->dst_port)) {
+ tb_port_warn(tunnel->dst_port,
+ "path does not end on a PCIe adapter, cleaning up\n");
+ goto err_deactivate;
+ }
+
+ if (down != tunnel->src_port) {
+ tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
+ goto err_deactivate;
+ }
+
+ if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
+ tb_tunnel_warn(tunnel,
+ "tunnel is not fully activated, cleaning up\n");
+ goto err_deactivate;
+ }
+
+ tb_tunnel_dbg(tunnel, "discovered\n");
+ return tunnel;
+
+err_deactivate:
+ tb_tunnel_deactivate(tunnel);
+err_free:
+ tb_tunnel_free(tunnel);
+
+ return NULL;
+}
+
+/**
+ * tb_tunnel_alloc_pci() - allocate a pci tunnel
+ * @tb: Pointer to the domain structure
+ * @up: PCIe upstream adapter port
+ * @down: PCIe downstream adapter port
+ *
+ * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
+ * TB_TYPE_PCIE_DOWN.
+ *
+ * Return: Returns a tb_tunnel on success or NULL on failure.
+ */
+struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
+ struct tb_port *down)
+{
+ struct tb_tunnel *tunnel;
+ struct tb_path *path;
+
+ tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
+ if (!tunnel)
+ return NULL;
+
+ tunnel->activate = tb_pci_activate;
+ tunnel->src_port = down;
+ tunnel->dst_port = up;
+
+ path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
+ "PCIe Down");
+ if (!path)
+ goto err_free;
+ tunnel->paths[TB_PCI_PATH_DOWN] = path;
+ if (tb_pci_init_path(path))
+ goto err_free;
+
+ path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
+ "PCIe Up");
+ if (!path)
+ goto err_free;
+ tunnel->paths[TB_PCI_PATH_UP] = path;
+ if (tb_pci_init_path(path))
+ goto err_free;
+
+ return tunnel;
+
+err_free:
+ tb_tunnel_free(tunnel);
+ return NULL;
+}
+
+static bool tb_dp_is_usb4(const struct tb_switch *sw)
+{
+ /* Titan Ridge DP adapters need the same treatment as USB4 */
+ return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
+}
+
+static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out,
+ int timeout_msec)
+{
+ ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
+ u32 val;
+ int ret;
+
+ /* Both ends need to support this */
+ if (!tb_dp_is_usb4(in->sw) || !tb_dp_is_usb4(out->sw))
+ return 0;
+
+ ret = tb_port_read(out, &val, TB_CFG_PORT,
+ out->cap_adap + DP_STATUS_CTRL, 1);
+ if (ret)
+ return ret;
+
+ val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
+
+ ret = tb_port_write(out, &val, TB_CFG_PORT,
+ out->cap_adap + DP_STATUS_CTRL, 1);
+ if (ret)
+ return ret;
+
+ do {
+ ret = tb_port_read(out, &val, TB_CFG_PORT,
+ out->cap_adap + DP_STATUS_CTRL, 1);
+ if (ret)
+ return ret;
+ if (!(val & DP_STATUS_CTRL_CMHS))
+ return 0;
+ usleep_range(100, 150);
+ } while (ktime_before(ktime_get(), timeout));
+
+ return -ETIMEDOUT;
+}
+
+/*
+ * Returns maximum possible rate from capability supporting only DP 2.0
+ * and below. Used when DP BW allocation mode is not enabled.
+ */
+static inline u32 tb_dp_cap_get_rate(u32 val)
+{
+ u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;
+
+ switch (rate) {
+ case DP_COMMON_CAP_RATE_RBR:
+ return 1620;
+ case DP_COMMON_CAP_RATE_HBR:
+ return 2700;
+ case DP_COMMON_CAP_RATE_HBR2:
+ return 5400;
+ case DP_COMMON_CAP_RATE_HBR3:
+ return 8100;
+ default:
+ return 0;
+ }
+}
+
+/*
+ * Returns maximum possible rate from capability supporting DP 2.1
+ * UHBR20, 13.5 and 10 rates as well. Use only when DP BW allocation
+ * mode is enabled.
+ */
+static inline u32 tb_dp_cap_get_rate_ext(u32 val)
+{
+ if (val & DP_COMMON_CAP_UHBR20)
+ return 20000;
+ else if (val & DP_COMMON_CAP_UHBR13_5)
+ return 13500;
+ else if (val & DP_COMMON_CAP_UHBR10)
+ return 10000;
+
+ return tb_dp_cap_get_rate(val);
+}
+
+static inline bool tb_dp_is_uhbr_rate(unsigned int rate)
+{
+ return rate >= 10000;
+}
+
+static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)
+{
+ val &= ~DP_COMMON_CAP_RATE_MASK;
+ switch (rate) {
+ default:
+ WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);
+ fallthrough;
+ case 1620:
+ val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;
+ break;
+ case 2700:
+ val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;
+ break;
+ case 5400:
+ val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;
+ break;
+ case 8100:
+ val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;
+ break;
+ }
+ return val;
+}
+
+static inline u32 tb_dp_cap_get_lanes(u32 val)
+{
+ u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;
+
+ switch (lanes) {
+ case DP_COMMON_CAP_1_LANE:
+ return 1;
+ case DP_COMMON_CAP_2_LANES:
+ return 2;
+ case DP_COMMON_CAP_4_LANES:
+ return 4;
+ default:
+ return 0;
+ }
+}
+
+static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)
+{
+ val &= ~DP_COMMON_CAP_LANES_MASK;
+ switch (lanes) {
+ default:
+ WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",
+ lanes);
+ fallthrough;
+ case 1:
+ val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;
+ break;
+ case 2:
+ val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;
+ break;
+ case 4:
+ val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;
+ break;
+ }
+ return val;
+}
+
+static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)
+{
+ /* Tunneling removes the DP 8b/10b 128/132b encoding */
+ if (tb_dp_is_uhbr_rate(rate))
+ return rate * lanes * 128 / 132;
+ return rate * lanes * 8 / 10;
+}
+
+static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,
+ u32 out_rate, u32 out_lanes, u32 *new_rate,
+ u32 *new_lanes)
+{
+ static const u32 dp_bw[][2] = {
+ /* Mb/s, lanes */
+ { 8100, 4 }, /* 25920 Mb/s */
+ { 5400, 4 }, /* 17280 Mb/s */
+ { 8100, 2 }, /* 12960 Mb/s */
+ { 2700, 4 }, /* 8640 Mb/s */
+ { 5400, 2 }, /* 8640 Mb/s */
+ { 8100, 1 }, /* 6480 Mb/s */
+ { 1620, 4 }, /* 5184 Mb/s */
+ { 5400, 1 }, /* 4320 Mb/s */
+ { 2700, 2 }, /* 4320 Mb/s */
+ { 1620, 2 }, /* 2592 Mb/s */
+ { 2700, 1 }, /* 2160 Mb/s */
+ { 1620, 1 }, /* 1296 Mb/s */
+ };
+ unsigned int i;
+
+ /*
+ * Find a combination that can fit into max_bw and does not
+ * exceed the maximum rate and lanes supported by the DP OUT and
+ * DP IN adapters.
+ */
+ for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {
+ if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)
+ continue;
+
+ if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)
+ continue;
+
+ if (tb_dp_bandwidth(dp_bw[i][0], dp_bw[i][1]) <= max_bw) {
+ *new_rate = dp_bw[i][0];
+ *new_lanes = dp_bw[i][1];
+ return 0;
+ }
+ }
+
+ return -ENOSR;
+}
+
+static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
+{
+ u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;
+ struct tb_port *out = tunnel->dst_port;
+ struct tb_port *in = tunnel->src_port;
+ int ret, max_bw;
+
+ /*
+ * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
+ * newer generation hardware.
+ */
+ if (in->sw->generation < 2 || out->sw->generation < 2)
+ return 0;
+
+ /*
+ * Perform connection manager handshake between IN and OUT ports
+ * before capabilities exchange can take place.
+ */
+ ret = tb_dp_cm_handshake(in, out, 3000);
+ if (ret)
+ return ret;
+
+ /* Read both DP_LOCAL_CAP registers */
+ ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
+ in->cap_adap + DP_LOCAL_CAP, 1);
+ if (ret)
+ return ret;
+
+ ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
+ out->cap_adap + DP_LOCAL_CAP, 1);
+ if (ret)
+ return ret;
+
+ /* Write IN local caps to OUT remote caps */
+ ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
+ out->cap_adap + DP_REMOTE_CAP, 1);
+ if (ret)
+ return ret;
+
+ in_rate = tb_dp_cap_get_rate(in_dp_cap);
+ in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
+ tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
+ in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));
+
+ /*
+ * If the tunnel bandwidth is limited (max_bw is set) then see
+ * if we need to reduce bandwidth to fit there.
+ */
+ out_rate = tb_dp_cap_get_rate(out_dp_cap);
+ out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
+ bw = tb_dp_bandwidth(out_rate, out_lanes);
+ tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
+ out_rate, out_lanes, bw);
+
+ if (in->sw->config.depth < out->sw->config.depth)
+ max_bw = tunnel->max_down;
+ else
+ max_bw = tunnel->max_up;
+
+ if (max_bw && bw > max_bw) {
+ u32 new_rate, new_lanes, new_bw;
+
+ ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,
+ out_rate, out_lanes, &new_rate,
+ &new_lanes);
+ if (ret) {
+ tb_port_info(out, "not enough bandwidth for DP tunnel\n");
+ return ret;
+ }
+
+ new_bw = tb_dp_bandwidth(new_rate, new_lanes);
+ tb_port_dbg(out, "bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",
+ new_rate, new_lanes, new_bw);
+
+ /*
+ * Set new rate and number of lanes before writing it to
+ * the IN port remote caps.
+ */
+ out_dp_cap = tb_dp_cap_set_rate(out_dp_cap, new_rate);
+ out_dp_cap = tb_dp_cap_set_lanes(out_dp_cap, new_lanes);
+ }
+
+ /*
+ * Titan Ridge does not disable AUX timers when it gets
+ * SET_CONFIG with SET_LTTPR_MODE set. This causes problems with
+ * DP tunneling.
+ */
+ if (tb_route(out->sw) && tb_switch_is_titan_ridge(out->sw)) {
+ out_dp_cap |= DP_COMMON_CAP_LTTPR_NS;
+ tb_port_dbg(out, "disabling LTTPR\n");
+ }
+
+ return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
+ in->cap_adap + DP_REMOTE_CAP, 1);
+}
+
+static int tb_dp_bandwidth_alloc_mode_enable(struct tb_tunnel *tunnel)
+{
+ int ret, estimated_bw, granularity, tmp;
+ struct tb_port *out = tunnel->dst_port;
+ struct tb_port *in = tunnel->src_port;
+ u32 out_dp_cap, out_rate, out_lanes;
+ u32 in_dp_cap, in_rate, in_lanes;
+ u32 rate, lanes;
+
+ if (!bw_alloc_mode)
+ return 0;
+
+ ret = usb4_dp_port_set_cm_bandwidth_mode_supported(in, true);
+ if (ret)
+ return ret;
+
+ ret = usb4_dp_port_set_group_id(in, in->group->index);
+ if (ret)
+ return ret;
+
+ /*
+ * Get the non-reduced rate and lanes based on the lowest
+ * capability of both adapters.
+ */
+ ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
+ in->cap_adap + DP_LOCAL_CAP, 1);
+ if (ret)
+ return ret;
+
+ ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
+ out->cap_adap + DP_LOCAL_CAP, 1);
+ if (ret)
+ return ret;
+
+ in_rate = tb_dp_cap_get_rate(in_dp_cap);
+ in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
+ out_rate = tb_dp_cap_get_rate(out_dp_cap);
+ out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
+
+ rate = min(in_rate, out_rate);
+ lanes = min(in_lanes, out_lanes);
+ tmp = tb_dp_bandwidth(rate, lanes);
+
+ tb_port_dbg(in, "non-reduced bandwidth %u Mb/s x%u = %u Mb/s\n", rate,
+ lanes, tmp);
+
+ ret = usb4_dp_port_set_nrd(in, rate, lanes);
+ if (ret)
+ return ret;
+
+ /*
+ * Pick up granularity that supports maximum possible bandwidth.
+ * For that we use the UHBR rates too.
+ */
+ in_rate = tb_dp_cap_get_rate_ext(in_dp_cap);
+ out_rate = tb_dp_cap_get_rate_ext(out_dp_cap);
+ rate = min(in_rate, out_rate);
+ tmp = tb_dp_bandwidth(rate, lanes);
+
+ tb_port_dbg(in,
+ "maximum bandwidth through allocation mode %u Mb/s x%u = %u Mb/s\n",
+ rate, lanes, tmp);
+
+ for (granularity = 250; tmp / granularity > 255 && granularity <= 1000;
+ granularity *= 2)
+ ;
+
+ tb_port_dbg(in, "granularity %d Mb/s\n", granularity);
+
+ /*
+ * Returns -EINVAL if granularity above is outside of the
+ * accepted ranges.
+ */
+ ret = usb4_dp_port_set_granularity(in, granularity);
+ if (ret)
+ return ret;
+
+ /*
+ * Bandwidth estimation is pretty much what we have in
+ * max_up/down fields. For discovery we just read what the
+ * estimation was set to.
+ */
+ if (in->sw->config.depth < out->sw->config.depth)
+ estimated_bw = tunnel->max_down;
+ else
+ estimated_bw = tunnel->max_up;
+
+ tb_port_dbg(in, "estimated bandwidth %d Mb/s\n", estimated_bw);
+
+ ret = usb4_dp_port_set_estimated_bandwidth(in, estimated_bw);
+ if (ret)
+ return ret;
+
+ /* Initial allocation should be 0 according the spec */
+ ret = usb4_dp_port_allocate_bandwidth(in, 0);
+ if (ret)
+ return ret;
+
+ tb_port_dbg(in, "bandwidth allocation mode enabled\n");
+ return 0;
+}
+
+static int tb_dp_init(struct tb_tunnel *tunnel)
+{
+ struct tb_port *in = tunnel->src_port;
+ struct tb_switch *sw = in->sw;
+ struct tb *tb = in->sw->tb;
+ int ret;
+
+ ret = tb_dp_xchg_caps(tunnel);
+ if (ret)
+ return ret;
+
+ if (!tb_switch_is_usb4(sw))
+ return 0;
+
+ if (!usb4_dp_port_bandwidth_mode_supported(in))
+ return 0;
+
+ tb_port_dbg(in, "bandwidth allocation mode supported\n");
+
+ ret = usb4_dp_port_set_cm_id(in, tb->index);
+ if (ret)
+ return ret;
+
+ return tb_dp_bandwidth_alloc_mode_enable(tunnel);
+}
+
+static void tb_dp_deinit(struct tb_tunnel *tunnel)
+{
+ struct tb_port *in = tunnel->src_port;
+
+ if (!usb4_dp_port_bandwidth_mode_supported(in))
+ return;
+ if (usb4_dp_port_bandwidth_mode_enabled(in)) {
+ usb4_dp_port_set_cm_bandwidth_mode_supported(in, false);
+ tb_port_dbg(in, "bandwidth allocation mode disabled\n");
+ }
+}
+
+static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
+{
+ int ret;
+
+ if (active) {
+ struct tb_path **paths;
+ int last;
+
+ paths = tunnel->paths;
+ last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
+
+ tb_dp_port_set_hops(tunnel->src_port,
+ paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
+ paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
+ paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
+
+ tb_dp_port_set_hops(tunnel->dst_port,
+ paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
+ paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
+ paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
+ } else {
+ tb_dp_port_hpd_clear(tunnel->src_port);
+ tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
+ if (tb_port_is_dpout(tunnel->dst_port))
+ tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
+ }
+
+ ret = tb_dp_port_enable(tunnel->src_port, active);
+ if (ret)
+ return ret;
+
+ if (tb_port_is_dpout(tunnel->dst_port))
+ return tb_dp_port_enable(tunnel->dst_port, active);
+
+ return 0;
+}
+
+/* max_bw is rounded up to next granularity */
+static int tb_dp_bandwidth_mode_maximum_bandwidth(struct tb_tunnel *tunnel,
+ int *max_bw)
+{
+ struct tb_port *in = tunnel->src_port;
+ int ret, rate, lanes, nrd_bw;
+ u32 cap;
+
+ /*
+ * DP IN adapter DP_LOCAL_CAP gets updated to the lowest AUX
+ * read parameter values so this so we can use this to determine
+ * the maximum possible bandwidth over this link.
+ *
+ * See USB4 v2 spec 1.0 10.4.4.5.
+ */
+ ret = tb_port_read(in, &cap, TB_CFG_PORT,
+ in->cap_adap + DP_LOCAL_CAP, 1);
+ if (ret)
+ return ret;
+
+ rate = tb_dp_cap_get_rate_ext(cap);
+ if (tb_dp_is_uhbr_rate(rate)) {
+ /*
+ * When UHBR is used there is no reduction in lanes so
+ * we can use this directly.
+ */
+ lanes = tb_dp_cap_get_lanes(cap);
+ } else {
+ /*
+ * If there is no UHBR supported then check the
+ * non-reduced rate and lanes.
+ */
+ ret = usb4_dp_port_nrd(in, &rate, &lanes);
+ if (ret)
+ return ret;
+ }
+
+ nrd_bw = tb_dp_bandwidth(rate, lanes);
+
+ if (max_bw) {
+ ret = usb4_dp_port_granularity(in);
+ if (ret < 0)
+ return ret;
+ *max_bw = roundup(nrd_bw, ret);
+ }
+
+ return nrd_bw;
+}
+
+static int tb_dp_bandwidth_mode_consumed_bandwidth(struct tb_tunnel *tunnel,
+ int *consumed_up,
+ int *consumed_down)
+{
+ struct tb_port *out = tunnel->dst_port;
+ struct tb_port *in = tunnel->src_port;
+ int ret, allocated_bw, max_bw;
+
+ if (!usb4_dp_port_bandwidth_mode_enabled(in))
+ return -EOPNOTSUPP;
+
+ if (!tunnel->bw_mode)
+ return -EOPNOTSUPP;
+
+ /* Read what was allocated previously if any */
+ ret = usb4_dp_port_allocated_bandwidth(in);
+ if (ret < 0)
+ return ret;
+ allocated_bw = ret;
+
+ ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
+ if (ret < 0)
+ return ret;
+ if (allocated_bw == max_bw)
+ allocated_bw = ret;
+
+ tb_port_dbg(in, "consumed bandwidth through allocation mode %d Mb/s\n",
+ allocated_bw);
+
+ if (in->sw->config.depth < out->sw->config.depth) {
+ *consumed_up = 0;
+ *consumed_down = allocated_bw;
+ } else {
+ *consumed_up = allocated_bw;
+ *consumed_down = 0;
+ }
+
+ return 0;
+}
+
+static int tb_dp_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
+ int *allocated_down)
+{
+ struct tb_port *out = tunnel->dst_port;
+ struct tb_port *in = tunnel->src_port;
+
+ /*
+ * If we have already set the allocated bandwidth then use that.
+ * Otherwise we read it from the DPRX.
+ */
+ if (usb4_dp_port_bandwidth_mode_enabled(in) && tunnel->bw_mode) {
+ int ret, allocated_bw, max_bw;
+
+ ret = usb4_dp_port_allocated_bandwidth(in);
+ if (ret < 0)
+ return ret;
+ allocated_bw = ret;
+
+ ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
+ if (ret < 0)
+ return ret;
+ if (allocated_bw == max_bw)
+ allocated_bw = ret;
+
+ if (in->sw->config.depth < out->sw->config.depth) {
+ *allocated_up = 0;
+ *allocated_down = allocated_bw;
+ } else {
+ *allocated_up = allocated_bw;
+ *allocated_down = 0;
+ }
+ return 0;
+ }
+
+ return tunnel->consumed_bandwidth(tunnel, allocated_up,
+ allocated_down);
+}
+
+static int tb_dp_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
+ int *alloc_down)
+{
+ struct tb_port *out = tunnel->dst_port;
+ struct tb_port *in = tunnel->src_port;
+ int max_bw, ret, tmp;
+
+ if (!usb4_dp_port_bandwidth_mode_enabled(in))
+ return -EOPNOTSUPP;
+
+ ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
+ if (ret < 0)
+ return ret;
+
+ if (in->sw->config.depth < out->sw->config.depth) {
+ tmp = min(*alloc_down, max_bw);
+ ret = usb4_dp_port_allocate_bandwidth(in, tmp);
+ if (ret)
+ return ret;
+ *alloc_down = tmp;
+ *alloc_up = 0;
+ } else {
+ tmp = min(*alloc_up, max_bw);
+ ret = usb4_dp_port_allocate_bandwidth(in, tmp);
+ if (ret)
+ return ret;
+ *alloc_down = 0;
+ *alloc_up = tmp;
+ }
+
+ /* Now we can use BW mode registers to figure out the bandwidth */
+ /* TODO: need to handle discovery too */
+ tunnel->bw_mode = true;
+
+ tb_port_dbg(in, "allocated bandwidth through allocation mode %d Mb/s\n",
+ tmp);
+ return 0;
+}
+
+static int tb_dp_read_dprx(struct tb_tunnel *tunnel, u32 *rate, u32 *lanes,
+ int timeout_msec)
+{
+ ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
+ struct tb_port *in = tunnel->src_port;
+
+ /*
+ * Wait for DPRX done. Normally it should be already set for
+ * active tunnel.
+ */
+ do {
+ u32 val;
+ int ret;
+
+ ret = tb_port_read(in, &val, TB_CFG_PORT,
+ in->cap_adap + DP_COMMON_CAP, 1);
+ if (ret)
+ return ret;
+
+ if (val & DP_COMMON_CAP_DPRX_DONE) {
+ *rate = tb_dp_cap_get_rate(val);
+ *lanes = tb_dp_cap_get_lanes(val);
+
+ tb_port_dbg(in, "consumed bandwidth through DPRX %d Mb/s\n",
+ tb_dp_bandwidth(*rate, *lanes));
+ return 0;
+ }
+ usleep_range(100, 150);
+ } while (ktime_before(ktime_get(), timeout));
+
+ return -ETIMEDOUT;
+}
+
+/* Read cap from tunnel DP IN */
+static int tb_dp_read_cap(struct tb_tunnel *tunnel, unsigned int cap, u32 *rate,
+ u32 *lanes)
+{
+ struct tb_port *in = tunnel->src_port;
+ u32 val;
+ int ret;
+
+ switch (cap) {
+ case DP_LOCAL_CAP:
+ case DP_REMOTE_CAP:
+ break;
+
+ default:
+ tb_tunnel_WARN(tunnel, "invalid capability index %#x\n", cap);
+ return -EINVAL;
+ }
+
+ /*
+ * Read from the copied remote cap so that we take into account
+ * if capabilities were reduced during exchange.
+ */
+ ret = tb_port_read(in, &val, TB_CFG_PORT, in->cap_adap + cap, 1);
+ if (ret)
+ return ret;
+
+ *rate = tb_dp_cap_get_rate(val);
+ *lanes = tb_dp_cap_get_lanes(val);
+
+ tb_port_dbg(in, "bandwidth from %#x capability %d Mb/s\n", cap,
+ tb_dp_bandwidth(*rate, *lanes));
+ return 0;
+}
+
+static int tb_dp_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
+ int *max_down)
+{
+ struct tb_port *in = tunnel->src_port;
+ int ret;
+
+ if (!usb4_dp_port_bandwidth_mode_enabled(in))
+ return -EOPNOTSUPP;
+
+ ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, NULL);
+ if (ret < 0)
+ return ret;
+
+ if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
+ *max_up = 0;
+ *max_down = ret;
+ } else {
+ *max_up = ret;
+ *max_down = 0;
+ }
+
+ return 0;
+}
+
+static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
+ int *consumed_down)
+{
+ struct tb_port *in = tunnel->src_port;
+ const struct tb_switch *sw = in->sw;
+ u32 rate = 0, lanes = 0;
+ int ret;
+
+ if (tb_dp_is_usb4(sw)) {
+ /*
+ * On USB4 routers check if the bandwidth allocation
+ * mode is enabled first and then read the bandwidth
+ * through those registers.
+ */
+ ret = tb_dp_bandwidth_mode_consumed_bandwidth(tunnel, consumed_up,
+ consumed_down);
+ if (ret < 0) {
+ if (ret != -EOPNOTSUPP)
+ return ret;
+ } else if (!ret) {
+ return 0;
+ }
+ /*
+ * Then see if the DPRX negotiation is ready and if yes
+ * return that bandwidth (it may be smaller than the
+ * reduced one). Otherwise return the remote (possibly
+ * reduced) caps.
+ */
+ ret = tb_dp_read_dprx(tunnel, &rate, &lanes, 150);
+ if (ret) {
+ if (ret == -ETIMEDOUT)
+ ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP,
+ &rate, &lanes);
+ if (ret)
+ return ret;
+ }
+ } else if (sw->generation >= 2) {
+ ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP, &rate, &lanes);
+ if (ret)
+ return ret;
+ } else {
+ /* No bandwidth management for legacy devices */
+ *consumed_up = 0;
+ *consumed_down = 0;
+ return 0;
+ }
+
+ if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
+ *consumed_up = 0;
+ *consumed_down = tb_dp_bandwidth(rate, lanes);
+ } else {
+ *consumed_up = tb_dp_bandwidth(rate, lanes);
+ *consumed_down = 0;
+ }
+
+ return 0;
+}
+
+static void tb_dp_init_aux_credits(struct tb_path_hop *hop)
+{
+ struct tb_port *port = hop->in_port;
+ struct tb_switch *sw = port->sw;
+
+ if (tb_port_use_credit_allocation(port))
+ hop->initial_credits = sw->min_dp_aux_credits;
+ else
+ hop->initial_credits = 1;
+}
+
+static void tb_dp_init_aux_path(struct tb_path *path)
+{
+ struct tb_path_hop *hop;
+
+ path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
+ path->egress_shared_buffer = TB_PATH_NONE;
+ path->ingress_fc_enable = TB_PATH_ALL;
+ path->ingress_shared_buffer = TB_PATH_NONE;
+ path->priority = 2;
+ path->weight = 1;
+
+ tb_path_for_each_hop(path, hop)
+ tb_dp_init_aux_credits(hop);
+}
+
+static int tb_dp_init_video_credits(struct tb_path_hop *hop)
+{
+ struct tb_port *port = hop->in_port;
+ struct tb_switch *sw = port->sw;
+
+ if (tb_port_use_credit_allocation(port)) {
+ unsigned int nfc_credits;
+ size_t max_dp_streams;
+
+ tb_available_credits(port, &max_dp_streams);
+ /*
+ * Read the number of currently allocated NFC credits
+ * from the lane adapter. Since we only use them for DP
+ * tunneling we can use that to figure out how many DP
+ * tunnels already go through the lane adapter.
+ */
+ nfc_credits = port->config.nfc_credits &
+ ADP_CS_4_NFC_BUFFERS_MASK;
+ if (nfc_credits / sw->min_dp_main_credits > max_dp_streams)
+ return -ENOSPC;
+
+ hop->nfc_credits = sw->min_dp_main_credits;
+ } else {
+ hop->nfc_credits = min(port->total_credits - 2, 12U);
+ }
+
+ return 0;
+}
+
+static int tb_dp_init_video_path(struct tb_path *path)
+{
+ struct tb_path_hop *hop;
+
+ path->egress_fc_enable = TB_PATH_NONE;
+ path->egress_shared_buffer = TB_PATH_NONE;
+ path->ingress_fc_enable = TB_PATH_NONE;
+ path->ingress_shared_buffer = TB_PATH_NONE;
+ path->priority = 1;
+ path->weight = 1;
+
+ tb_path_for_each_hop(path, hop) {
+ int ret;
+
+ ret = tb_dp_init_video_credits(hop);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static void tb_dp_dump(struct tb_tunnel *tunnel)
+{
+ struct tb_port *in, *out;
+ u32 dp_cap, rate, lanes;
+
+ in = tunnel->src_port;
+ out = tunnel->dst_port;
+
+ if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
+ in->cap_adap + DP_LOCAL_CAP, 1))
+ return;
+
+ rate = tb_dp_cap_get_rate(dp_cap);
+ lanes = tb_dp_cap_get_lanes(dp_cap);
+
+ tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
+ rate, lanes, tb_dp_bandwidth(rate, lanes));
+
+ out = tunnel->dst_port;
+
+ if (tb_port_read(out, &dp_cap, TB_CFG_PORT,
+ out->cap_adap + DP_LOCAL_CAP, 1))
+ return;
+
+ rate = tb_dp_cap_get_rate(dp_cap);
+ lanes = tb_dp_cap_get_lanes(dp_cap);
+
+ tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
+ rate, lanes, tb_dp_bandwidth(rate, lanes));
+
+ if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
+ in->cap_adap + DP_REMOTE_CAP, 1))
+ return;
+
+ rate = tb_dp_cap_get_rate(dp_cap);
+ lanes = tb_dp_cap_get_lanes(dp_cap);
+
+ tb_port_dbg(in, "reduced bandwidth %u Mb/s x%u = %u Mb/s\n",
+ rate, lanes, tb_dp_bandwidth(rate, lanes));
+}
+
+/**
+ * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
+ * @tb: Pointer to the domain structure
+ * @in: DP in adapter
+ * @alloc_hopid: Allocate HopIDs from visited ports
+ *
+ * If @in adapter is active, follows the tunnel to the DP out adapter
+ * and back. Returns the discovered tunnel or %NULL if there was no
+ * tunnel.
+ *
+ * Return: DP tunnel or %NULL if no tunnel found.
+ */
+struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
+ bool alloc_hopid)
+{
+ struct tb_tunnel *tunnel;
+ struct tb_port *port;
+ struct tb_path *path;
+
+ if (!tb_dp_port_is_enabled(in))
+ return NULL;
+
+ tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
+ if (!tunnel)
+ return NULL;
+
+ tunnel->init = tb_dp_init;
+ tunnel->deinit = tb_dp_deinit;
+ tunnel->activate = tb_dp_activate;
+ tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
+ tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
+ tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
+ tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
+ tunnel->src_port = in;
+
+ path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
+ &tunnel->dst_port, "Video", alloc_hopid);
+ if (!path) {
+ /* Just disable the DP IN port */
+ tb_dp_port_enable(in, false);
+ goto err_free;
+ }
+ tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
+ if (tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT]))
+ goto err_free;
+
+ path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX",
+ alloc_hopid);
+ if (!path)
+ goto err_deactivate;
+ tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
+ tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
+
+ path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
+ &port, "AUX RX", alloc_hopid);
+ if (!path)
+ goto err_deactivate;
+ tunnel->paths[TB_DP_AUX_PATH_IN] = path;
+ tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
+
+ /* Validate that the tunnel is complete */
+ if (!tb_port_is_dpout(tunnel->dst_port)) {
+ tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
+ goto err_deactivate;
+ }
+
+ if (!tb_dp_port_is_enabled(tunnel->dst_port))
+ goto err_deactivate;
+
+ if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
+ goto err_deactivate;
+
+ if (port != tunnel->src_port) {
+ tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
+ goto err_deactivate;
+ }
+
+ tb_dp_dump(tunnel);
+
+ tb_tunnel_dbg(tunnel, "discovered\n");
+ return tunnel;
+
+err_deactivate:
+ tb_tunnel_deactivate(tunnel);
+err_free:
+ tb_tunnel_free(tunnel);
+
+ return NULL;
+}
+
+/**
+ * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
+ * @tb: Pointer to the domain structure
+ * @in: DP in adapter port
+ * @out: DP out adapter port
+ * @link_nr: Preferred lane adapter when the link is not bonded
+ * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
+ * if not limited)
+ * @max_down: Maximum available downstream bandwidth for the DP tunnel
+ * (%0 if not limited)
+ *
+ * Allocates a tunnel between @in and @out that is capable of tunneling
+ * Display Port traffic.
+ *
+ * Return: Returns a tb_tunnel on success or NULL on failure.
+ */
+struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
+ struct tb_port *out, int link_nr,
+ int max_up, int max_down)
+{
+ struct tb_tunnel *tunnel;
+ struct tb_path **paths;
+ struct tb_path *path;
+
+ if (WARN_ON(!in->cap_adap || !out->cap_adap))
+ return NULL;
+
+ tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
+ if (!tunnel)
+ return NULL;
+
+ tunnel->init = tb_dp_init;
+ tunnel->deinit = tb_dp_deinit;
+ tunnel->activate = tb_dp_activate;
+ tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
+ tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
+ tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
+ tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
+ tunnel->src_port = in;
+ tunnel->dst_port = out;
+ tunnel->max_up = max_up;
+ tunnel->max_down = max_down;
+
+ paths = tunnel->paths;
+
+ path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
+ link_nr, "Video");
+ if (!path)
+ goto err_free;
+ tb_dp_init_video_path(path);
+ paths[TB_DP_VIDEO_PATH_OUT] = path;
+
+ path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
+ TB_DP_AUX_TX_HOPID, link_nr, "AUX TX");
+ if (!path)
+ goto err_free;
+ tb_dp_init_aux_path(path);
+ paths[TB_DP_AUX_PATH_OUT] = path;
+
+ path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
+ TB_DP_AUX_RX_HOPID, link_nr, "AUX RX");
+ if (!path)
+ goto err_free;
+ tb_dp_init_aux_path(path);
+ paths[TB_DP_AUX_PATH_IN] = path;
+
+ return tunnel;
+
+err_free:
+ tb_tunnel_free(tunnel);
+ return NULL;
+}
+
+static unsigned int tb_dma_available_credits(const struct tb_port *port)
+{
+ const struct tb_switch *sw = port->sw;
+ int credits;
+
+ credits = tb_available_credits(port, NULL);
+ if (tb_acpi_may_tunnel_pcie())
+ credits -= sw->max_pcie_credits;
+ credits -= port->dma_credits;
+
+ return credits > 0 ? credits : 0;
+}
+
+static int tb_dma_reserve_credits(struct tb_path_hop *hop, unsigned int credits)
+{
+ struct tb_port *port = hop->in_port;
+
+ if (tb_port_use_credit_allocation(port)) {
+ unsigned int available = tb_dma_available_credits(port);
+
+ /*
+ * Need to have at least TB_MIN_DMA_CREDITS, otherwise
+ * DMA path cannot be established.
+ */
+ if (available < TB_MIN_DMA_CREDITS)
+ return -ENOSPC;
+
+ while (credits > available)
+ credits--;
+
+ tb_port_dbg(port, "reserving %u credits for DMA path\n",
+ credits);
+
+ port->dma_credits += credits;
+ } else {
+ if (tb_port_is_null(port))
+ credits = port->bonded ? 14 : 6;
+ else
+ credits = min(port->total_credits, credits);
+ }
+
+ hop->initial_credits = credits;
+ return 0;
+}
+
+/* Path from lane adapter to NHI */
+static int tb_dma_init_rx_path(struct tb_path *path, unsigned int credits)
+{
+ struct tb_path_hop *hop;
+ unsigned int i, tmp;
+
+ path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
+ path->ingress_fc_enable = TB_PATH_ALL;
+ path->egress_shared_buffer = TB_PATH_NONE;
+ path->ingress_shared_buffer = TB_PATH_NONE;
+ path->priority = 5;
+ path->weight = 1;
+ path->clear_fc = true;
+
+ /*
+ * First lane adapter is the one connected to the remote host.
+ * We don't tunnel other traffic over this link so can use all
+ * the credits (except the ones reserved for control traffic).
+ */
+ hop = &path->hops[0];
+ tmp = min(tb_usable_credits(hop->in_port), credits);
+ hop->initial_credits = tmp;
+ hop->in_port->dma_credits += tmp;
+
+ for (i = 1; i < path->path_length; i++) {
+ int ret;
+
+ ret = tb_dma_reserve_credits(&path->hops[i], credits);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/* Path from NHI to lane adapter */
+static int tb_dma_init_tx_path(struct tb_path *path, unsigned int credits)
+{
+ struct tb_path_hop *hop;
+
+ path->egress_fc_enable = TB_PATH_ALL;
+ path->ingress_fc_enable = TB_PATH_ALL;
+ path->egress_shared_buffer = TB_PATH_NONE;
+ path->ingress_shared_buffer = TB_PATH_NONE;
+ path->priority = 5;
+ path->weight = 1;
+ path->clear_fc = true;
+
+ tb_path_for_each_hop(path, hop) {
+ int ret;
+
+ ret = tb_dma_reserve_credits(hop, credits);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static void tb_dma_release_credits(struct tb_path_hop *hop)
+{
+ struct tb_port *port = hop->in_port;
+
+ if (tb_port_use_credit_allocation(port)) {
+ port->dma_credits -= hop->initial_credits;
+
+ tb_port_dbg(port, "released %u DMA path credits\n",
+ hop->initial_credits);
+ }
+}
+
+static void tb_dma_deinit_path(struct tb_path *path)
+{
+ struct tb_path_hop *hop;
+
+ tb_path_for_each_hop(path, hop)
+ tb_dma_release_credits(hop);
+}
+
+static void tb_dma_deinit(struct tb_tunnel *tunnel)
+{
+ int i;
+
+ for (i = 0; i < tunnel->npaths; i++) {
+ if (!tunnel->paths[i])
+ continue;
+ tb_dma_deinit_path(tunnel->paths[i]);
+ }
+}
+
+/**
+ * tb_tunnel_alloc_dma() - allocate a DMA tunnel
+ * @tb: Pointer to the domain structure
+ * @nhi: Host controller port
+ * @dst: Destination null port which the other domain is connected to
+ * @transmit_path: HopID used for transmitting packets
+ * @transmit_ring: NHI ring number used to send packets towards the
+ * other domain. Set to %-1 if TX path is not needed.
+ * @receive_path: HopID used for receiving packets
+ * @receive_ring: NHI ring number used to receive packets from the
+ * other domain. Set to %-1 if RX path is not needed.
+ *
+ * Return: Returns a tb_tunnel on success or NULL on failure.
+ */
+struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
+ struct tb_port *dst, int transmit_path,
+ int transmit_ring, int receive_path,
+ int receive_ring)
+{
+ struct tb_tunnel *tunnel;
+ size_t npaths = 0, i = 0;
+ struct tb_path *path;
+ int credits;
+
+ /* Ring 0 is reserved for control channel */
+ if (WARN_ON(!receive_ring || !transmit_ring))
+ return NULL;
+
+ if (receive_ring > 0)
+ npaths++;
+ if (transmit_ring > 0)
+ npaths++;
+
+ if (WARN_ON(!npaths))
+ return NULL;
+
+ tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
+ if (!tunnel)
+ return NULL;
+
+ tunnel->src_port = nhi;
+ tunnel->dst_port = dst;
+ tunnel->deinit = tb_dma_deinit;
+
+ credits = min_not_zero(dma_credits, nhi->sw->max_dma_credits);
+
+ if (receive_ring > 0) {
+ path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
+ "DMA RX");
+ if (!path)
+ goto err_free;
+ tunnel->paths[i++] = path;
+ if (tb_dma_init_rx_path(path, credits)) {
+ tb_tunnel_dbg(tunnel, "not enough buffers for RX path\n");
+ goto err_free;
+ }
+ }
+
+ if (transmit_ring > 0) {
+ path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
+ "DMA TX");
+ if (!path)
+ goto err_free;
+ tunnel->paths[i++] = path;
+ if (tb_dma_init_tx_path(path, credits)) {
+ tb_tunnel_dbg(tunnel, "not enough buffers for TX path\n");
+ goto err_free;
+ }
+ }
+
+ return tunnel;
+
+err_free:
+ tb_tunnel_free(tunnel);
+ return NULL;
+}
+
+/**
+ * tb_tunnel_match_dma() - Match DMA tunnel
+ * @tunnel: Tunnel to match
+ * @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.
+ * @transmit_ring: NHI ring number used to send packets towards the
+ * other domain. Pass %-1 to ignore.
+ * @receive_path: HopID used for receiving packets. Pass %-1 to ignore.
+ * @receive_ring: NHI ring number used to receive packets from the
+ * other domain. Pass %-1 to ignore.
+ *
+ * This function can be used to match specific DMA tunnel, if there are
+ * multiple DMA tunnels going through the same XDomain connection.
+ * Returns true if there is match and false otherwise.
+ */
+bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,
+ int transmit_ring, int receive_path, int receive_ring)
+{
+ const struct tb_path *tx_path = NULL, *rx_path = NULL;
+ int i;
+
+ if (!receive_ring || !transmit_ring)
+ return false;
+
+ for (i = 0; i < tunnel->npaths; i++) {
+ const struct tb_path *path = tunnel->paths[i];
+
+ if (!path)
+ continue;
+
+ if (tb_port_is_nhi(path->hops[0].in_port))
+ tx_path = path;
+ else if (tb_port_is_nhi(path->hops[path->path_length - 1].out_port))
+ rx_path = path;
+ }
+
+ if (transmit_ring > 0 || transmit_path > 0) {
+ if (!tx_path)
+ return false;
+ if (transmit_ring > 0 &&
+ (tx_path->hops[0].in_hop_index != transmit_ring))
+ return false;
+ if (transmit_path > 0 &&
+ (tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))
+ return false;
+ }
+
+ if (receive_ring > 0 || receive_path > 0) {
+ if (!rx_path)
+ return false;
+ if (receive_path > 0 &&
+ (rx_path->hops[0].in_hop_index != receive_path))
+ return false;
+ if (receive_ring > 0 &&
+ (rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))
+ return false;
+ }
+
+ return true;
+}
+
+static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
+{
+ int ret, up_max_rate, down_max_rate;
+
+ ret = usb4_usb3_port_max_link_rate(up);
+ if (ret < 0)
+ return ret;
+ up_max_rate = ret;
+
+ ret = usb4_usb3_port_max_link_rate(down);
+ if (ret < 0)
+ return ret;
+ down_max_rate = ret;
+
+ return min(up_max_rate, down_max_rate);
+}
+
+static int tb_usb3_init(struct tb_tunnel *tunnel)
+{
+ tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
+ tunnel->allocated_up, tunnel->allocated_down);
+
+ return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,
+ &tunnel->allocated_up,
+ &tunnel->allocated_down);
+}
+
+static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
+{
+ int res;
+
+ res = tb_usb3_port_enable(tunnel->src_port, activate);
+ if (res)
+ return res;
+
+ if (tb_port_is_usb3_up(tunnel->dst_port))
+ return tb_usb3_port_enable(tunnel->dst_port, activate);
+
+ return 0;
+}
+
+static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
+ int *consumed_up, int *consumed_down)
+{
+ int pcie_enabled = tb_acpi_may_tunnel_pcie();
+
+ /*
+ * PCIe tunneling, if enabled, affects the USB3 bandwidth so
+ * take that it into account here.
+ */
+ *consumed_up = tunnel->allocated_up * (3 + pcie_enabled) / 3;
+ *consumed_down = tunnel->allocated_down * (3 + pcie_enabled) / 3;
+ return 0;
+}
+
+static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
+{
+ int ret;
+
+ ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,
+ &tunnel->allocated_up,
+ &tunnel->allocated_down);
+ if (ret)
+ return ret;
+
+ tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
+ tunnel->allocated_up, tunnel->allocated_down);
+ return 0;
+}
+
+static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
+ int *available_up,
+ int *available_down)
+{
+ int ret, max_rate, allocate_up, allocate_down;
+
+ ret = usb4_usb3_port_actual_link_rate(tunnel->src_port);
+ if (ret < 0) {
+ tb_tunnel_warn(tunnel, "failed to read actual link rate\n");
+ return;
+ } else if (!ret) {
+ /* Use maximum link rate if the link valid is not set */
+ ret = tb_usb3_max_link_rate(tunnel->dst_port, tunnel->src_port);
+ if (ret < 0) {
+ tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
+ return;
+ }
+ }
+
+ /*
+ * 90% of the max rate can be allocated for isochronous
+ * transfers.
+ */
+ max_rate = ret * 90 / 100;
+
+ /* No need to reclaim if already at maximum */
+ if (tunnel->allocated_up >= max_rate &&
+ tunnel->allocated_down >= max_rate)
+ return;
+
+ /* Don't go lower than what is already allocated */
+ allocate_up = min(max_rate, *available_up);
+ if (allocate_up < tunnel->allocated_up)
+ allocate_up = tunnel->allocated_up;
+
+ allocate_down = min(max_rate, *available_down);
+ if (allocate_down < tunnel->allocated_down)
+ allocate_down = tunnel->allocated_down;
+
+ /* If no changes no need to do more */
+ if (allocate_up == tunnel->allocated_up &&
+ allocate_down == tunnel->allocated_down)
+ return;
+
+ ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,
+ &allocate_down);
+ if (ret) {
+ tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
+ return;
+ }
+
+ tunnel->allocated_up = allocate_up;
+ *available_up -= tunnel->allocated_up;
+
+ tunnel->allocated_down = allocate_down;
+ *available_down -= tunnel->allocated_down;
+
+ tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
+ tunnel->allocated_up, tunnel->allocated_down);
+}
+
+static void tb_usb3_init_credits(struct tb_path_hop *hop)
+{
+ struct tb_port *port = hop->in_port;
+ struct tb_switch *sw = port->sw;
+ unsigned int credits;
+
+ if (tb_port_use_credit_allocation(port)) {
+ credits = sw->max_usb3_credits;
+ } else {
+ if (tb_port_is_null(port))
+ credits = port->bonded ? 32 : 16;
+ else
+ credits = 7;
+ }
+
+ hop->initial_credits = credits;
+}
+
+static void tb_usb3_init_path(struct tb_path *path)
+{
+ struct tb_path_hop *hop;
+
+ path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
+ path->egress_shared_buffer = TB_PATH_NONE;
+ path->ingress_fc_enable = TB_PATH_ALL;
+ path->ingress_shared_buffer = TB_PATH_NONE;
+ path->priority = 3;
+ path->weight = 3;
+ path->drop_packages = 0;
+
+ tb_path_for_each_hop(path, hop)
+ tb_usb3_init_credits(hop);
+}
+
+/**
+ * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
+ * @tb: Pointer to the domain structure
+ * @down: USB3 downstream adapter
+ * @alloc_hopid: Allocate HopIDs from visited ports
+ *
+ * If @down adapter is active, follows the tunnel to the USB3 upstream
+ * adapter and back. Returns the discovered tunnel or %NULL if there was
+ * no tunnel.
+ */
+struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down,
+ bool alloc_hopid)
+{
+ struct tb_tunnel *tunnel;
+ struct tb_path *path;
+
+ if (!tb_usb3_port_is_enabled(down))
+ return NULL;
+
+ tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
+ if (!tunnel)
+ return NULL;
+
+ tunnel->activate = tb_usb3_activate;
+ tunnel->src_port = down;
+
+ /*
+ * Discover both paths even if they are not complete. We will
+ * clean them up by calling tb_tunnel_deactivate() below in that
+ * case.
+ */
+ path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
+ &tunnel->dst_port, "USB3 Down", alloc_hopid);
+ if (!path) {
+ /* Just disable the downstream port */
+ tb_usb3_port_enable(down, false);
+ goto err_free;
+ }
+ tunnel->paths[TB_USB3_PATH_DOWN] = path;
+ tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);
+
+ path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
+ "USB3 Up", alloc_hopid);
+ if (!path)
+ goto err_deactivate;
+ tunnel->paths[TB_USB3_PATH_UP] = path;
+ tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);
+
+ /* Validate that the tunnel is complete */
+ if (!tb_port_is_usb3_up(tunnel->dst_port)) {
+ tb_port_warn(tunnel->dst_port,
+ "path does not end on an USB3 adapter, cleaning up\n");
+ goto err_deactivate;
+ }
+
+ if (down != tunnel->src_port) {
+ tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
+ goto err_deactivate;
+ }
+
+ if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {
+ tb_tunnel_warn(tunnel,
+ "tunnel is not fully activated, cleaning up\n");
+ goto err_deactivate;
+ }
+
+ if (!tb_route(down->sw)) {
+ int ret;
+
+ /*
+ * Read the initial bandwidth allocation for the first
+ * hop tunnel.
+ */
+ ret = usb4_usb3_port_allocated_bandwidth(down,
+ &tunnel->allocated_up, &tunnel->allocated_down);
+ if (ret)
+ goto err_deactivate;
+
+ tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
+ tunnel->allocated_up, tunnel->allocated_down);
+
+ tunnel->init = tb_usb3_init;
+ tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
+ tunnel->release_unused_bandwidth =
+ tb_usb3_release_unused_bandwidth;
+ tunnel->reclaim_available_bandwidth =
+ tb_usb3_reclaim_available_bandwidth;
+ }
+
+ tb_tunnel_dbg(tunnel, "discovered\n");
+ return tunnel;
+
+err_deactivate:
+ tb_tunnel_deactivate(tunnel);
+err_free:
+ tb_tunnel_free(tunnel);
+
+ return NULL;
+}
+
+/**
+ * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
+ * @tb: Pointer to the domain structure
+ * @up: USB3 upstream adapter port
+ * @down: USB3 downstream adapter port
+ * @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
+ * if not limited).
+ * @max_down: Maximum available downstream bandwidth for the USB3 tunnel
+ * (%0 if not limited).
+ *
+ * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
+ * @TB_TYPE_USB3_DOWN.
+ *
+ * Return: Returns a tb_tunnel on success or %NULL on failure.
+ */
+struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
+ struct tb_port *down, int max_up,
+ int max_down)
+{
+ struct tb_tunnel *tunnel;
+ struct tb_path *path;
+ int max_rate = 0;
+
+ /*
+ * Check that we have enough bandwidth available for the new
+ * USB3 tunnel.
+ */
+ if (max_up > 0 || max_down > 0) {
+ max_rate = tb_usb3_max_link_rate(down, up);
+ if (max_rate < 0)
+ return NULL;
+
+ /* Only 90% can be allocated for USB3 isochronous transfers */
+ max_rate = max_rate * 90 / 100;
+ tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
+ max_rate);
+
+ if (max_rate > max_up || max_rate > max_down) {
+ tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
+ return NULL;
+ }
+ }
+
+ tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
+ if (!tunnel)
+ return NULL;
+
+ tunnel->activate = tb_usb3_activate;
+ tunnel->src_port = down;
+ tunnel->dst_port = up;
+ tunnel->max_up = max_up;
+ tunnel->max_down = max_down;
+
+ path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
+ "USB3 Down");
+ if (!path) {
+ tb_tunnel_free(tunnel);
+ return NULL;
+ }
+ tb_usb3_init_path(path);
+ tunnel->paths[TB_USB3_PATH_DOWN] = path;
+
+ path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,
+ "USB3 Up");
+ if (!path) {
+ tb_tunnel_free(tunnel);
+ return NULL;
+ }
+ tb_usb3_init_path(path);
+ tunnel->paths[TB_USB3_PATH_UP] = path;
+
+ if (!tb_route(down->sw)) {
+ tunnel->allocated_up = max_rate;
+ tunnel->allocated_down = max_rate;
+
+ tunnel->init = tb_usb3_init;
+ tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
+ tunnel->release_unused_bandwidth =
+ tb_usb3_release_unused_bandwidth;
+ tunnel->reclaim_available_bandwidth =
+ tb_usb3_reclaim_available_bandwidth;
+ }
+
+ return tunnel;
+}
+
+/**
+ * tb_tunnel_free() - free a tunnel
+ * @tunnel: Tunnel to be freed
+ *
+ * Frees a tunnel. The tunnel does not need to be deactivated.
+ */
+void tb_tunnel_free(struct tb_tunnel *tunnel)
+{
+ int i;
+
+ if (!tunnel)
+ return;
+
+ if (tunnel->deinit)
+ tunnel->deinit(tunnel);
+
+ for (i = 0; i < tunnel->npaths; i++) {
+ if (tunnel->paths[i])
+ tb_path_free(tunnel->paths[i]);
+ }
+
+ kfree(tunnel->paths);
+ kfree(tunnel);
+}
+
+/**
+ * tb_tunnel_is_invalid - check whether an activated path is still valid
+ * @tunnel: Tunnel to check
+ */
+bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
+{
+ int i;
+
+ for (i = 0; i < tunnel->npaths; i++) {
+ WARN_ON(!tunnel->paths[i]->activated);
+ if (tb_path_is_invalid(tunnel->paths[i]))
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * tb_tunnel_restart() - activate a tunnel after a hardware reset
+ * @tunnel: Tunnel to restart
+ *
+ * Return: 0 on success and negative errno in case if failure
+ */
+int tb_tunnel_restart(struct tb_tunnel *tunnel)
+{
+ int res, i;
+
+ tb_tunnel_dbg(tunnel, "activating\n");
+
+ /*
+ * Make sure all paths are properly disabled before enabling
+ * them again.
+ */
+ for (i = 0; i < tunnel->npaths; i++) {
+ if (tunnel->paths[i]->activated) {
+ tb_path_deactivate(tunnel->paths[i]);
+ tunnel->paths[i]->activated = false;
+ }
+ }
+
+ if (tunnel->init) {
+ res = tunnel->init(tunnel);
+ if (res)
+ return res;
+ }
+
+ for (i = 0; i < tunnel->npaths; i++) {
+ res = tb_path_activate(tunnel->paths[i]);
+ if (res)
+ goto err;
+ }
+
+ if (tunnel->activate) {
+ res = tunnel->activate(tunnel, true);
+ if (res)
+ goto err;
+ }
+
+ return 0;
+
+err:
+ tb_tunnel_warn(tunnel, "activation failed\n");
+ tb_tunnel_deactivate(tunnel);
+ return res;
+}
+
+/**
+ * tb_tunnel_activate() - activate a tunnel
+ * @tunnel: Tunnel to activate
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_tunnel_activate(struct tb_tunnel *tunnel)
+{
+ int i;
+
+ for (i = 0; i < tunnel->npaths; i++) {
+ if (tunnel->paths[i]->activated) {
+ tb_tunnel_WARN(tunnel,
+ "trying to activate an already activated tunnel\n");
+ return -EINVAL;
+ }
+ }
+
+ return tb_tunnel_restart(tunnel);
+}
+
+/**
+ * tb_tunnel_deactivate() - deactivate a tunnel
+ * @tunnel: Tunnel to deactivate
+ */
+void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
+{
+ int i;
+
+ tb_tunnel_dbg(tunnel, "deactivating\n");
+
+ if (tunnel->activate)
+ tunnel->activate(tunnel, false);
+
+ for (i = 0; i < tunnel->npaths; i++) {
+ if (tunnel->paths[i] && tunnel->paths[i]->activated)
+ tb_path_deactivate(tunnel->paths[i]);
+ }
+}
+
+/**
+ * tb_tunnel_port_on_path() - Does the tunnel go through port
+ * @tunnel: Tunnel to check
+ * @port: Port to check
+ *
+ * Returns true if @tunnel goes through @port (direction does not matter),
+ * false otherwise.
+ */
+bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
+ const struct tb_port *port)
+{
+ int i;
+
+ for (i = 0; i < tunnel->npaths; i++) {
+ if (!tunnel->paths[i])
+ continue;
+
+ if (tb_path_port_on_path(tunnel->paths[i], port))
+ return true;
+ }
+
+ return false;
+}
+
+static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
+{
+ int i;
+
+ for (i = 0; i < tunnel->npaths; i++) {
+ if (!tunnel->paths[i])
+ return false;
+ if (!tunnel->paths[i]->activated)
+ return false;
+ }
+
+ return true;
+}
+
+/**
+ * tb_tunnel_maximum_bandwidth() - Return maximum possible bandwidth
+ * @tunnel: Tunnel to check
+ * @max_up: Maximum upstream bandwidth in Mb/s
+ * @max_down: Maximum downstream bandwidth in Mb/s
+ *
+ * Returns maximum possible bandwidth this tunnel can go if not limited
+ * by other bandwidth clients. If the tunnel does not support this
+ * returns %-EOPNOTSUPP.
+ */
+int tb_tunnel_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
+ int *max_down)
+{
+ if (!tb_tunnel_is_active(tunnel))
+ return -EINVAL;
+
+ if (tunnel->maximum_bandwidth)
+ return tunnel->maximum_bandwidth(tunnel, max_up, max_down);
+ return -EOPNOTSUPP;
+}
+
+/**
+ * tb_tunnel_allocated_bandwidth() - Return bandwidth allocated for the tunnel
+ * @tunnel: Tunnel to check
+ * @allocated_up: Currently allocated upstream bandwidth in Mb/s is stored here
+ * @allocated_down: Currently allocated downstream bandwidth in Mb/s is
+ * stored here
+ *
+ * Returns the bandwidth allocated for the tunnel. This may be higher
+ * than what the tunnel actually consumes.
+ */
+int tb_tunnel_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
+ int *allocated_down)
+{
+ if (!tb_tunnel_is_active(tunnel))
+ return -EINVAL;
+
+ if (tunnel->allocated_bandwidth)
+ return tunnel->allocated_bandwidth(tunnel, allocated_up,
+ allocated_down);
+ return -EOPNOTSUPP;
+}
+
+/**
+ * tb_tunnel_alloc_bandwidth() - Change tunnel bandwidth allocation
+ * @tunnel: Tunnel whose bandwidth allocation to change
+ * @alloc_up: New upstream bandwidth in Mb/s
+ * @alloc_down: New downstream bandwidth in Mb/s
+ *
+ * Tries to change tunnel bandwidth allocation. If succeeds returns %0
+ * and updates @alloc_up and @alloc_down to that was actually allocated
+ * (it may not be the same as passed originally). Returns negative errno
+ * in case of failure.
+ */
+int tb_tunnel_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
+ int *alloc_down)
+{
+ if (!tb_tunnel_is_active(tunnel))
+ return -EINVAL;
+
+ if (tunnel->alloc_bandwidth)
+ return tunnel->alloc_bandwidth(tunnel, alloc_up, alloc_down);
+
+ return -EOPNOTSUPP;
+}
+
+/**
+ * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
+ * @tunnel: Tunnel to check
+ * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
+ * Can be %NULL.
+ * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
+ * Can be %NULL.
+ *
+ * Stores the amount of isochronous bandwidth @tunnel consumes in
+ * @consumed_up and @consumed_down. In case of success returns %0,
+ * negative errno otherwise.
+ */
+int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
+ int *consumed_down)
+{
+ int up_bw = 0, down_bw = 0;
+
+ if (!tb_tunnel_is_active(tunnel))
+ goto out;
+
+ if (tunnel->consumed_bandwidth) {
+ int ret;
+
+ ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
+ if (ret)
+ return ret;
+
+ tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
+ down_bw);
+ }
+
+out:
+ if (consumed_up)
+ *consumed_up = up_bw;
+ if (consumed_down)
+ *consumed_down = down_bw;
+
+ return 0;
+}
+
+/**
+ * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
+ * @tunnel: Tunnel whose unused bandwidth to release
+ *
+ * If tunnel supports dynamic bandwidth management (USB3 tunnels at the
+ * moment) this function makes it to release all the unused bandwidth.
+ *
+ * Returns %0 in case of success and negative errno otherwise.
+ */
+int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
+{
+ if (!tb_tunnel_is_active(tunnel))
+ return 0;
+
+ if (tunnel->release_unused_bandwidth) {
+ int ret;
+
+ ret = tunnel->release_unused_bandwidth(tunnel);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
+ * @tunnel: Tunnel reclaiming available bandwidth
+ * @available_up: Available upstream bandwidth (in Mb/s)
+ * @available_down: Available downstream bandwidth (in Mb/s)
+ *
+ * Reclaims bandwidth from @available_up and @available_down and updates
+ * the variables accordingly (e.g decreases both according to what was
+ * reclaimed by the tunnel). If nothing was reclaimed the values are
+ * kept as is.
+ */
+void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
+ int *available_up,
+ int *available_down)
+{
+ if (!tb_tunnel_is_active(tunnel))
+ return;
+
+ if (tunnel->reclaim_available_bandwidth)
+ tunnel->reclaim_available_bandwidth(tunnel, available_up,
+ available_down);
+}