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1// SPDX-License-Identifier: GPL-2.02/*3 * Thunderbolt driver - Tunneling support4 *5 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>6 * Copyright (C) 2019, Intel Corporation7 */8 9#include <linux/delay.h>10#include <linux/slab.h>11#include <linux/list.h>12#include <linux/ktime.h>13#include <linux/string_helpers.h>14 15#include "tunnel.h"16#include "tb.h"17 18/* PCIe adapters use always HopID of 8 for both directions */19#define TB_PCI_HOPID			820 21#define TB_PCI_PATH_DOWN		022#define TB_PCI_PATH_UP			123 24#define TB_PCI_PRIORITY			325#define TB_PCI_WEIGHT			126 27/* USB3 adapters use always HopID of 8 for both directions */28#define TB_USB3_HOPID			829 30#define TB_USB3_PATH_DOWN		031#define TB_USB3_PATH_UP			132 33#define TB_USB3_PRIORITY		334#define TB_USB3_WEIGHT			235 36/* DP adapters use HopID 8 for AUX and 9 for Video */37#define TB_DP_AUX_TX_HOPID		838#define TB_DP_AUX_RX_HOPID		839#define TB_DP_VIDEO_HOPID		940 41#define TB_DP_VIDEO_PATH_OUT		042#define TB_DP_AUX_PATH_OUT		143#define TB_DP_AUX_PATH_IN		244 45#define TB_DP_VIDEO_PRIORITY		146#define TB_DP_VIDEO_WEIGHT		147 48#define TB_DP_AUX_PRIORITY		249#define TB_DP_AUX_WEIGHT		150 51/* Minimum number of credits needed for PCIe path */52#define TB_MIN_PCIE_CREDITS		6U53/*54 * Number of credits we try to allocate for each DMA path if not limited55 * by the host router baMaxHI.56 */57#define TB_DMA_CREDITS			1458/* Minimum number of credits for DMA path */59#define TB_MIN_DMA_CREDITS		160 61#define TB_DMA_PRIORITY			562#define TB_DMA_WEIGHT			163 64/*65 * Reserve additional bandwidth for USB 3.x and PCIe bulk traffic66 * according to USB4 v2 Connection Manager guide. This ends up reserving67 * 1500 Mb/s for PCIe and 3000 Mb/s for USB 3.x taking weights into68 * account.69 */70#define USB4_V2_PCI_MIN_BANDWIDTH	(1500 * TB_PCI_WEIGHT)71#define USB4_V2_USB3_MIN_BANDWIDTH	(1500 * TB_USB3_WEIGHT)72 73static unsigned int dma_credits = TB_DMA_CREDITS;74module_param(dma_credits, uint, 0444);75MODULE_PARM_DESC(dma_credits, "specify custom credits for DMA tunnels (default: "76                __MODULE_STRING(TB_DMA_CREDITS) ")");77 78static bool bw_alloc_mode = true;79module_param(bw_alloc_mode, bool, 0444);80MODULE_PARM_DESC(bw_alloc_mode,81		 "enable bandwidth allocation mode if supported (default: true)");82 83static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };84 85static inline unsigned int tb_usable_credits(const struct tb_port *port)86{87	return port->total_credits - port->ctl_credits;88}89 90/**91 * tb_available_credits() - Available credits for PCIe and DMA92 * @port: Lane adapter to check93 * @max_dp_streams: If non-%NULL stores maximum number of simultaneous DP94 *		    streams possible through this lane adapter95 */96static unsigned int tb_available_credits(const struct tb_port *port,97					 size_t *max_dp_streams)98{99	const struct tb_switch *sw = port->sw;100	int credits, usb3, pcie, spare;101	size_t ndp;102 103	usb3 = tb_acpi_may_tunnel_usb3() ? sw->max_usb3_credits : 0;104	pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0;105 106	if (tb_acpi_is_xdomain_allowed()) {107		spare = min_not_zero(sw->max_dma_credits, dma_credits);108		/* Add some credits for potential second DMA tunnel */109		spare += TB_MIN_DMA_CREDITS;110	} else {111		spare = 0;112	}113 114	credits = tb_usable_credits(port);115	if (tb_acpi_may_tunnel_dp()) {116		/*117		 * Maximum number of DP streams possible through the118		 * lane adapter.119		 */120		if (sw->min_dp_aux_credits + sw->min_dp_main_credits)121			ndp = (credits - (usb3 + pcie + spare)) /122			      (sw->min_dp_aux_credits + sw->min_dp_main_credits);123		else124			ndp = 0;125	} else {126		ndp = 0;127	}128	credits -= ndp * (sw->min_dp_aux_credits + sw->min_dp_main_credits);129	credits -= usb3;130 131	if (max_dp_streams)132		*max_dp_streams = ndp;133 134	return credits > 0 ? credits : 0;135}136 137static void tb_init_pm_support(struct tb_path_hop *hop)138{139	struct tb_port *out_port = hop->out_port;140	struct tb_port *in_port = hop->in_port;141 142	if (tb_port_is_null(in_port) && tb_port_is_null(out_port) &&143	    usb4_switch_version(in_port->sw) >= 2)144		hop->pm_support = true;145}146 147static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,148					 enum tb_tunnel_type type)149{150	struct tb_tunnel *tunnel;151 152	tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);153	if (!tunnel)154		return NULL;155 156	tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);157	if (!tunnel->paths) {158		tb_tunnel_free(tunnel);159		return NULL;160	}161 162	INIT_LIST_HEAD(&tunnel->list);163	tunnel->tb = tb;164	tunnel->npaths = npaths;165	tunnel->type = type;166 167	return tunnel;168}169 170static int tb_pci_set_ext_encapsulation(struct tb_tunnel *tunnel, bool enable)171{172	struct tb_port *port = tb_upstream_port(tunnel->dst_port->sw);173	int ret;174 175	/* Only supported of both routers are at least USB4 v2 */176	if ((usb4_switch_version(tunnel->src_port->sw) < 2) ||177	   (usb4_switch_version(tunnel->dst_port->sw) < 2))178		return 0;179 180	if (enable && tb_port_get_link_generation(port) < 4)181		return 0;182 183	ret = usb4_pci_port_set_ext_encapsulation(tunnel->src_port, enable);184	if (ret)185		return ret;186 187	/*188	 * Downstream router could be unplugged so disable of encapsulation189	 * in upstream router is still possible.190	 */191	ret = usb4_pci_port_set_ext_encapsulation(tunnel->dst_port, enable);192	if (ret) {193		if (enable)194			return ret;195		if (ret != -ENODEV)196			return ret;197	}198 199	tb_tunnel_dbg(tunnel, "extended encapsulation %s\n",200		      str_enabled_disabled(enable));201	return 0;202}203 204static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)205{206	int res;207 208	if (activate) {209		res = tb_pci_set_ext_encapsulation(tunnel, activate);210		if (res)211			return res;212	}213 214	if (activate)215		res = tb_pci_port_enable(tunnel->dst_port, activate);216	else217		res = tb_pci_port_enable(tunnel->src_port, activate);218	if (res)219		return res;220 221 222	if (activate) {223		res = tb_pci_port_enable(tunnel->src_port, activate);224		if (res)225			return res;226	} else {227		/* Downstream router could be unplugged */228		tb_pci_port_enable(tunnel->dst_port, activate);229	}230 231	return activate ? 0 : tb_pci_set_ext_encapsulation(tunnel, activate);232}233 234static int tb_pci_init_credits(struct tb_path_hop *hop)235{236	struct tb_port *port = hop->in_port;237	struct tb_switch *sw = port->sw;238	unsigned int credits;239 240	if (tb_port_use_credit_allocation(port)) {241		unsigned int available;242 243		available = tb_available_credits(port, NULL);244		credits = min(sw->max_pcie_credits, available);245 246		if (credits < TB_MIN_PCIE_CREDITS)247			return -ENOSPC;248 249		credits = max(TB_MIN_PCIE_CREDITS, credits);250	} else {251		if (tb_port_is_null(port))252			credits = port->bonded ? 32 : 16;253		else254			credits = 7;255	}256 257	hop->initial_credits = credits;258	return 0;259}260 261static int tb_pci_init_path(struct tb_path *path)262{263	struct tb_path_hop *hop;264 265	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;266	path->egress_shared_buffer = TB_PATH_NONE;267	path->ingress_fc_enable = TB_PATH_ALL;268	path->ingress_shared_buffer = TB_PATH_NONE;269	path->priority = TB_PCI_PRIORITY;270	path->weight = TB_PCI_WEIGHT;271	path->drop_packages = 0;272 273	tb_path_for_each_hop(path, hop) {274		int ret;275 276		ret = tb_pci_init_credits(hop);277		if (ret)278			return ret;279	}280 281	return 0;282}283 284/**285 * tb_tunnel_discover_pci() - Discover existing PCIe tunnels286 * @tb: Pointer to the domain structure287 * @down: PCIe downstream adapter288 * @alloc_hopid: Allocate HopIDs from visited ports289 *290 * If @down adapter is active, follows the tunnel to the PCIe upstream291 * adapter and back. Returns the discovered tunnel or %NULL if there was292 * no tunnel.293 */294struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,295					 bool alloc_hopid)296{297	struct tb_tunnel *tunnel;298	struct tb_path *path;299 300	if (!tb_pci_port_is_enabled(down))301		return NULL;302 303	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);304	if (!tunnel)305		return NULL;306 307	tunnel->activate = tb_pci_activate;308	tunnel->src_port = down;309 310	/*311	 * Discover both paths even if they are not complete. We will312	 * clean them up by calling tb_tunnel_deactivate() below in that313	 * case.314	 */315	path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,316				&tunnel->dst_port, "PCIe Up", alloc_hopid);317	if (!path) {318		/* Just disable the downstream port */319		tb_pci_port_enable(down, false);320		goto err_free;321	}322	tunnel->paths[TB_PCI_PATH_UP] = path;323	if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]))324		goto err_free;325 326	path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,327				"PCIe Down", alloc_hopid);328	if (!path)329		goto err_deactivate;330	tunnel->paths[TB_PCI_PATH_DOWN] = path;331	if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]))332		goto err_deactivate;333 334	/* Validate that the tunnel is complete */335	if (!tb_port_is_pcie_up(tunnel->dst_port)) {336		tb_port_warn(tunnel->dst_port,337			     "path does not end on a PCIe adapter, cleaning up\n");338		goto err_deactivate;339	}340 341	if (down != tunnel->src_port) {342		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");343		goto err_deactivate;344	}345 346	if (!tb_pci_port_is_enabled(tunnel->dst_port)) {347		tb_tunnel_warn(tunnel,348			       "tunnel is not fully activated, cleaning up\n");349		goto err_deactivate;350	}351 352	tb_tunnel_dbg(tunnel, "discovered\n");353	return tunnel;354 355err_deactivate:356	tb_tunnel_deactivate(tunnel);357err_free:358	tb_tunnel_free(tunnel);359 360	return NULL;361}362 363/**364 * tb_tunnel_alloc_pci() - allocate a pci tunnel365 * @tb: Pointer to the domain structure366 * @up: PCIe upstream adapter port367 * @down: PCIe downstream adapter port368 *369 * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and370 * TB_TYPE_PCIE_DOWN.371 *372 * Return: Returns a tb_tunnel on success or NULL on failure.373 */374struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,375				      struct tb_port *down)376{377	struct tb_tunnel *tunnel;378	struct tb_path *path;379 380	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);381	if (!tunnel)382		return NULL;383 384	tunnel->activate = tb_pci_activate;385	tunnel->src_port = down;386	tunnel->dst_port = up;387 388	path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,389			     "PCIe Down");390	if (!path)391		goto err_free;392	tunnel->paths[TB_PCI_PATH_DOWN] = path;393	if (tb_pci_init_path(path))394		goto err_free;395 396	path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,397			     "PCIe Up");398	if (!path)399		goto err_free;400	tunnel->paths[TB_PCI_PATH_UP] = path;401	if (tb_pci_init_path(path))402		goto err_free;403 404	return tunnel;405 406err_free:407	tb_tunnel_free(tunnel);408	return NULL;409}410 411/**412 * tb_tunnel_reserved_pci() - Amount of bandwidth to reserve for PCIe413 * @port: Lane 0 adapter414 * @reserved_up: Upstream bandwidth in Mb/s to reserve415 * @reserved_down: Downstream bandwidth in Mb/s to reserve416 *417 * Can be called to any connected lane 0 adapter to find out how much418 * bandwidth needs to be left in reserve for possible PCIe bulk traffic.419 * Returns true if there is something to be reserved and writes the420 * amount to @reserved_down/@reserved_up. Otherwise returns false and421 * does not touch the parameters.422 */423bool tb_tunnel_reserved_pci(struct tb_port *port, int *reserved_up,424			    int *reserved_down)425{426	if (WARN_ON_ONCE(!port->remote))427		return false;428 429	if (!tb_acpi_may_tunnel_pcie())430		return false;431 432	if (tb_port_get_link_generation(port) < 4)433		return false;434 435	/* Must have PCIe adapters */436	if (tb_is_upstream_port(port)) {437		if (!tb_switch_find_port(port->sw, TB_TYPE_PCIE_UP))438			return false;439		if (!tb_switch_find_port(port->remote->sw, TB_TYPE_PCIE_DOWN))440			return false;441	} else {442		if (!tb_switch_find_port(port->sw, TB_TYPE_PCIE_DOWN))443			return false;444		if (!tb_switch_find_port(port->remote->sw, TB_TYPE_PCIE_UP))445			return false;446	}447 448	*reserved_up = USB4_V2_PCI_MIN_BANDWIDTH;449	*reserved_down = USB4_V2_PCI_MIN_BANDWIDTH;450 451	tb_port_dbg(port, "reserving %u/%u Mb/s for PCIe\n", *reserved_up,452		    *reserved_down);453	return true;454}455 456static bool tb_dp_is_usb4(const struct tb_switch *sw)457{458	/* Titan Ridge DP adapters need the same treatment as USB4 */459	return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);460}461 462static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out,463			      int timeout_msec)464{465	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);466	u32 val;467	int ret;468 469	/* Both ends need to support this */470	if (!tb_dp_is_usb4(in->sw) || !tb_dp_is_usb4(out->sw))471		return 0;472 473	ret = tb_port_read(out, &val, TB_CFG_PORT,474			   out->cap_adap + DP_STATUS_CTRL, 1);475	if (ret)476		return ret;477 478	val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;479 480	ret = tb_port_write(out, &val, TB_CFG_PORT,481			    out->cap_adap + DP_STATUS_CTRL, 1);482	if (ret)483		return ret;484 485	do {486		ret = tb_port_read(out, &val, TB_CFG_PORT,487				   out->cap_adap + DP_STATUS_CTRL, 1);488		if (ret)489			return ret;490		if (!(val & DP_STATUS_CTRL_CMHS))491			return 0;492		usleep_range(100, 150);493	} while (ktime_before(ktime_get(), timeout));494 495	return -ETIMEDOUT;496}497 498/*499 * Returns maximum possible rate from capability supporting only DP 2.0500 * and below. Used when DP BW allocation mode is not enabled.501 */502static inline u32 tb_dp_cap_get_rate(u32 val)503{504	u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;505 506	switch (rate) {507	case DP_COMMON_CAP_RATE_RBR:508		return 1620;509	case DP_COMMON_CAP_RATE_HBR:510		return 2700;511	case DP_COMMON_CAP_RATE_HBR2:512		return 5400;513	case DP_COMMON_CAP_RATE_HBR3:514		return 8100;515	default:516		return 0;517	}518}519 520/*521 * Returns maximum possible rate from capability supporting DP 2.1522 * UHBR20, 13.5 and 10 rates as well. Use only when DP BW allocation523 * mode is enabled.524 */525static inline u32 tb_dp_cap_get_rate_ext(u32 val)526{527	if (val & DP_COMMON_CAP_UHBR20)528		return 20000;529	else if (val & DP_COMMON_CAP_UHBR13_5)530		return 13500;531	else if (val & DP_COMMON_CAP_UHBR10)532		return 10000;533 534	return tb_dp_cap_get_rate(val);535}536 537static inline bool tb_dp_is_uhbr_rate(unsigned int rate)538{539	return rate >= 10000;540}541 542static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)543{544	val &= ~DP_COMMON_CAP_RATE_MASK;545	switch (rate) {546	default:547		WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);548		fallthrough;549	case 1620:550		val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;551		break;552	case 2700:553		val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;554		break;555	case 5400:556		val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;557		break;558	case 8100:559		val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;560		break;561	}562	return val;563}564 565static inline u32 tb_dp_cap_get_lanes(u32 val)566{567	u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;568 569	switch (lanes) {570	case DP_COMMON_CAP_1_LANE:571		return 1;572	case DP_COMMON_CAP_2_LANES:573		return 2;574	case DP_COMMON_CAP_4_LANES:575		return 4;576	default:577		return 0;578	}579}580 581static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)582{583	val &= ~DP_COMMON_CAP_LANES_MASK;584	switch (lanes) {585	default:586		WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",587		     lanes);588		fallthrough;589	case 1:590		val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;591		break;592	case 2:593		val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;594		break;595	case 4:596		val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;597		break;598	}599	return val;600}601 602static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)603{604	/* Tunneling removes the DP 8b/10b 128/132b encoding */605	if (tb_dp_is_uhbr_rate(rate))606		return rate * lanes * 128 / 132;607	return rate * lanes * 8 / 10;608}609 610static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,611				  u32 out_rate, u32 out_lanes, u32 *new_rate,612				  u32 *new_lanes)613{614	static const u32 dp_bw[][2] = {615		/* Mb/s, lanes */616		{ 8100, 4 }, /* 25920 Mb/s */617		{ 5400, 4 }, /* 17280 Mb/s */618		{ 8100, 2 }, /* 12960 Mb/s */619		{ 2700, 4 }, /* 8640 Mb/s */620		{ 5400, 2 }, /* 8640 Mb/s */621		{ 8100, 1 }, /* 6480 Mb/s */622		{ 1620, 4 }, /* 5184 Mb/s */623		{ 5400, 1 }, /* 4320 Mb/s */624		{ 2700, 2 }, /* 4320 Mb/s */625		{ 1620, 2 }, /* 2592 Mb/s */626		{ 2700, 1 }, /* 2160 Mb/s */627		{ 1620, 1 }, /* 1296 Mb/s */628	};629	unsigned int i;630 631	/*632	 * Find a combination that can fit into max_bw and does not633	 * exceed the maximum rate and lanes supported by the DP OUT and634	 * DP IN adapters.635	 */636	for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {637		if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)638			continue;639 640		if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)641			continue;642 643		if (tb_dp_bandwidth(dp_bw[i][0], dp_bw[i][1]) <= max_bw) {644			*new_rate = dp_bw[i][0];645			*new_lanes = dp_bw[i][1];646			return 0;647		}648	}649 650	return -ENOSR;651}652 653static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)654{655	u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;656	struct tb_port *out = tunnel->dst_port;657	struct tb_port *in = tunnel->src_port;658	int ret, max_bw;659 660	/*661	 * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for662	 * newer generation hardware.663	 */664	if (in->sw->generation < 2 || out->sw->generation < 2)665		return 0;666 667	/*668	 * Perform connection manager handshake between IN and OUT ports669	 * before capabilities exchange can take place.670	 */671	ret = tb_dp_cm_handshake(in, out, 3000);672	if (ret)673		return ret;674 675	/* Read both DP_LOCAL_CAP registers */676	ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,677			   in->cap_adap + DP_LOCAL_CAP, 1);678	if (ret)679		return ret;680 681	ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,682			   out->cap_adap + DP_LOCAL_CAP, 1);683	if (ret)684		return ret;685 686	/* Write IN local caps to OUT remote caps */687	ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,688			    out->cap_adap + DP_REMOTE_CAP, 1);689	if (ret)690		return ret;691 692	in_rate = tb_dp_cap_get_rate(in_dp_cap);693	in_lanes = tb_dp_cap_get_lanes(in_dp_cap);694	tb_tunnel_dbg(tunnel,695		      "DP IN maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",696		      in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));697 698	/*699	 * If the tunnel bandwidth is limited (max_bw is set) then see700	 * if we need to reduce bandwidth to fit there.701	 */702	out_rate = tb_dp_cap_get_rate(out_dp_cap);703	out_lanes = tb_dp_cap_get_lanes(out_dp_cap);704	bw = tb_dp_bandwidth(out_rate, out_lanes);705	tb_tunnel_dbg(tunnel,706		      "DP OUT maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",707		      out_rate, out_lanes, bw);708 709	if (tb_tunnel_direction_downstream(tunnel))710		max_bw = tunnel->max_down;711	else712		max_bw = tunnel->max_up;713 714	if (max_bw && bw > max_bw) {715		u32 new_rate, new_lanes, new_bw;716 717		ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,718					     out_rate, out_lanes, &new_rate,719					     &new_lanes);720		if (ret) {721			tb_tunnel_info(tunnel, "not enough bandwidth\n");722			return ret;723		}724 725		new_bw = tb_dp_bandwidth(new_rate, new_lanes);726		tb_tunnel_dbg(tunnel,727			      "bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",728			      new_rate, new_lanes, new_bw);729 730		/*731		 * Set new rate and number of lanes before writing it to732		 * the IN port remote caps.733		 */734		out_dp_cap = tb_dp_cap_set_rate(out_dp_cap, new_rate);735		out_dp_cap = tb_dp_cap_set_lanes(out_dp_cap, new_lanes);736	}737 738	/*739	 * Titan Ridge does not disable AUX timers when it gets740	 * SET_CONFIG with SET_LTTPR_MODE set. This causes problems with741	 * DP tunneling.742	 */743	if (tb_route(out->sw) && tb_switch_is_titan_ridge(out->sw)) {744		out_dp_cap |= DP_COMMON_CAP_LTTPR_NS;745		tb_tunnel_dbg(tunnel, "disabling LTTPR\n");746	}747 748	return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,749			     in->cap_adap + DP_REMOTE_CAP, 1);750}751 752static int tb_dp_bandwidth_alloc_mode_enable(struct tb_tunnel *tunnel)753{754	int ret, estimated_bw, granularity, tmp;755	struct tb_port *out = tunnel->dst_port;756	struct tb_port *in = tunnel->src_port;757	u32 out_dp_cap, out_rate, out_lanes;758	u32 in_dp_cap, in_rate, in_lanes;759	u32 rate, lanes;760 761	if (!bw_alloc_mode)762		return 0;763 764	ret = usb4_dp_port_set_cm_bandwidth_mode_supported(in, true);765	if (ret)766		return ret;767 768	ret = usb4_dp_port_set_group_id(in, in->group->index);769	if (ret)770		return ret;771 772	/*773	 * Get the non-reduced rate and lanes based on the lowest774	 * capability of both adapters.775	 */776	ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,777			   in->cap_adap + DP_LOCAL_CAP, 1);778	if (ret)779		return ret;780 781	ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,782			   out->cap_adap + DP_LOCAL_CAP, 1);783	if (ret)784		return ret;785 786	in_rate = tb_dp_cap_get_rate(in_dp_cap);787	in_lanes = tb_dp_cap_get_lanes(in_dp_cap);788	out_rate = tb_dp_cap_get_rate(out_dp_cap);789	out_lanes = tb_dp_cap_get_lanes(out_dp_cap);790 791	rate = min(in_rate, out_rate);792	lanes = min(in_lanes, out_lanes);793	tmp = tb_dp_bandwidth(rate, lanes);794 795	tb_tunnel_dbg(tunnel, "non-reduced bandwidth %u Mb/s x%u = %u Mb/s\n",796		      rate, lanes, tmp);797 798	ret = usb4_dp_port_set_nrd(in, rate, lanes);799	if (ret)800		return ret;801 802	/*803	 * Pick up granularity that supports maximum possible bandwidth.804	 * For that we use the UHBR rates too.805	 */806	in_rate = tb_dp_cap_get_rate_ext(in_dp_cap);807	out_rate = tb_dp_cap_get_rate_ext(out_dp_cap);808	rate = min(in_rate, out_rate);809	tmp = tb_dp_bandwidth(rate, lanes);810 811	tb_tunnel_dbg(tunnel,812		      "maximum bandwidth through allocation mode %u Mb/s x%u = %u Mb/s\n",813		      rate, lanes, tmp);814 815	for (granularity = 250; tmp / granularity > 255 && granularity <= 1000;816	     granularity *= 2)817		;818 819	tb_tunnel_dbg(tunnel, "granularity %d Mb/s\n", granularity);820 821	/*822	 * Returns -EINVAL if granularity above is outside of the823	 * accepted ranges.824	 */825	ret = usb4_dp_port_set_granularity(in, granularity);826	if (ret)827		return ret;828 829	/*830	 * Bandwidth estimation is pretty much what we have in831	 * max_up/down fields. For discovery we just read what the832	 * estimation was set to.833	 */834	if (tb_tunnel_direction_downstream(tunnel))835		estimated_bw = tunnel->max_down;836	else837		estimated_bw = tunnel->max_up;838 839	tb_tunnel_dbg(tunnel, "estimated bandwidth %d Mb/s\n", estimated_bw);840 841	ret = usb4_dp_port_set_estimated_bandwidth(in, estimated_bw);842	if (ret)843		return ret;844 845	/* Initial allocation should be 0 according the spec */846	ret = usb4_dp_port_allocate_bandwidth(in, 0);847	if (ret)848		return ret;849 850	tb_tunnel_dbg(tunnel, "bandwidth allocation mode enabled\n");851	return 0;852}853 854static int tb_dp_init(struct tb_tunnel *tunnel)855{856	struct tb_port *in = tunnel->src_port;857	struct tb_switch *sw = in->sw;858	struct tb *tb = in->sw->tb;859	int ret;860 861	ret = tb_dp_xchg_caps(tunnel);862	if (ret)863		return ret;864 865	if (!tb_switch_is_usb4(sw))866		return 0;867 868	if (!usb4_dp_port_bandwidth_mode_supported(in))869		return 0;870 871	tb_tunnel_dbg(tunnel, "bandwidth allocation mode supported\n");872 873	ret = usb4_dp_port_set_cm_id(in, tb->index);874	if (ret)875		return ret;876 877	return tb_dp_bandwidth_alloc_mode_enable(tunnel);878}879 880static void tb_dp_deinit(struct tb_tunnel *tunnel)881{882	struct tb_port *in = tunnel->src_port;883 884	if (!usb4_dp_port_bandwidth_mode_supported(in))885		return;886	if (usb4_dp_port_bandwidth_mode_enabled(in)) {887		usb4_dp_port_set_cm_bandwidth_mode_supported(in, false);888		tb_tunnel_dbg(tunnel, "bandwidth allocation mode disabled\n");889	}890}891 892static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)893{894	int ret;895 896	if (active) {897		struct tb_path **paths;898		int last;899 900		paths = tunnel->paths;901		last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;902 903		tb_dp_port_set_hops(tunnel->src_port,904			paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,905			paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,906			paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);907 908		tb_dp_port_set_hops(tunnel->dst_port,909			paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,910			paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,911			paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);912	} else {913		tb_dp_port_hpd_clear(tunnel->src_port);914		tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);915		if (tb_port_is_dpout(tunnel->dst_port))916			tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);917	}918 919	ret = tb_dp_port_enable(tunnel->src_port, active);920	if (ret)921		return ret;922 923	if (tb_port_is_dpout(tunnel->dst_port))924		return tb_dp_port_enable(tunnel->dst_port, active);925 926	return 0;927}928 929/**930 * tb_dp_bandwidth_mode_maximum_bandwidth() - Maximum possible bandwidth931 * @tunnel: DP tunnel to check932 * @max_bw_rounded: Maximum bandwidth in Mb/s rounded up to the next granularity933 *934 * Returns maximum possible bandwidth for this tunnel in Mb/s.935 */936static int tb_dp_bandwidth_mode_maximum_bandwidth(struct tb_tunnel *tunnel,937						  int *max_bw_rounded)938{939	struct tb_port *in = tunnel->src_port;940	int ret, rate, lanes, max_bw;941	u32 cap;942 943	/*944	 * DP IN adapter DP_LOCAL_CAP gets updated to the lowest AUX945	 * read parameter values so this so we can use this to determine946	 * the maximum possible bandwidth over this link.947	 *948	 * See USB4 v2 spec 1.0 10.4.4.5.949	 */950	ret = tb_port_read(in, &cap, TB_CFG_PORT,951			   in->cap_adap + DP_LOCAL_CAP, 1);952	if (ret)953		return ret;954 955	rate = tb_dp_cap_get_rate_ext(cap);956	lanes = tb_dp_cap_get_lanes(cap);957 958	max_bw = tb_dp_bandwidth(rate, lanes);959 960	if (max_bw_rounded) {961		ret = usb4_dp_port_granularity(in);962		if (ret < 0)963			return ret;964		*max_bw_rounded = roundup(max_bw, ret);965	}966 967	return max_bw;968}969 970static int tb_dp_bandwidth_mode_consumed_bandwidth(struct tb_tunnel *tunnel,971						   int *consumed_up,972						   int *consumed_down)973{974	struct tb_port *in = tunnel->src_port;975	int ret, allocated_bw, max_bw_rounded;976 977	if (!usb4_dp_port_bandwidth_mode_enabled(in))978		return -EOPNOTSUPP;979 980	if (!tunnel->bw_mode)981		return -EOPNOTSUPP;982 983	/* Read what was allocated previously if any */984	ret = usb4_dp_port_allocated_bandwidth(in);985	if (ret < 0)986		return ret;987	allocated_bw = ret;988 989	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw_rounded);990	if (ret < 0)991		return ret;992	if (allocated_bw == max_bw_rounded)993		allocated_bw = ret;994 995	if (tb_tunnel_direction_downstream(tunnel)) {996		*consumed_up = 0;997		*consumed_down = allocated_bw;998	} else {999		*consumed_up = allocated_bw;1000		*consumed_down = 0;1001	}1002 1003	return 0;1004}1005 1006static int tb_dp_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,1007				     int *allocated_down)1008{1009	struct tb_port *in = tunnel->src_port;1010 1011	/*1012	 * If we have already set the allocated bandwidth then use that.1013	 * Otherwise we read it from the DPRX.1014	 */1015	if (usb4_dp_port_bandwidth_mode_enabled(in) && tunnel->bw_mode) {1016		int ret, allocated_bw, max_bw_rounded;1017 1018		ret = usb4_dp_port_allocated_bandwidth(in);1019		if (ret < 0)1020			return ret;1021		allocated_bw = ret;1022 1023		ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel,1024							     &max_bw_rounded);1025		if (ret < 0)1026			return ret;1027		if (allocated_bw == max_bw_rounded)1028			allocated_bw = ret;1029 1030		if (tb_tunnel_direction_downstream(tunnel)) {1031			*allocated_up = 0;1032			*allocated_down = allocated_bw;1033		} else {1034			*allocated_up = allocated_bw;1035			*allocated_down = 0;1036		}1037		return 0;1038	}1039 1040	return tunnel->consumed_bandwidth(tunnel, allocated_up,1041					  allocated_down);1042}1043 1044static int tb_dp_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,1045				 int *alloc_down)1046{1047	struct tb_port *in = tunnel->src_port;1048	int max_bw_rounded, ret, tmp;1049 1050	if (!usb4_dp_port_bandwidth_mode_enabled(in))1051		return -EOPNOTSUPP;1052 1053	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw_rounded);1054	if (ret < 0)1055		return ret;1056 1057	if (tb_tunnel_direction_downstream(tunnel)) {1058		tmp = min(*alloc_down, max_bw_rounded);1059		ret = usb4_dp_port_allocate_bandwidth(in, tmp);1060		if (ret)1061			return ret;1062		*alloc_down = tmp;1063		*alloc_up = 0;1064	} else {1065		tmp = min(*alloc_up, max_bw_rounded);1066		ret = usb4_dp_port_allocate_bandwidth(in, tmp);1067		if (ret)1068			return ret;1069		*alloc_down = 0;1070		*alloc_up = tmp;1071	}1072 1073	/* Now we can use BW mode registers to figure out the bandwidth */1074	/* TODO: need to handle discovery too */1075	tunnel->bw_mode = true;1076	return 0;1077}1078 1079static int tb_dp_wait_dprx(struct tb_tunnel *tunnel, int timeout_msec)1080{1081	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);1082	struct tb_port *in = tunnel->src_port;1083 1084	/*1085	 * Wait for DPRX done. Normally it should be already set for1086	 * active tunnel.1087	 */1088	do {1089		u32 val;1090		int ret;1091 1092		ret = tb_port_read(in, &val, TB_CFG_PORT,1093				   in->cap_adap + DP_COMMON_CAP, 1);1094		if (ret)1095			return ret;1096 1097		if (val & DP_COMMON_CAP_DPRX_DONE) {1098			tb_tunnel_dbg(tunnel, "DPRX read done\n");1099			return 0;1100		}1101		usleep_range(100, 150);1102	} while (ktime_before(ktime_get(), timeout));1103 1104	tb_tunnel_dbg(tunnel, "DPRX read timeout\n");1105	return -ETIMEDOUT;1106}1107 1108/* Read cap from tunnel DP IN */1109static int tb_dp_read_cap(struct tb_tunnel *tunnel, unsigned int cap, u32 *rate,1110			  u32 *lanes)1111{1112	struct tb_port *in = tunnel->src_port;1113	u32 val;1114	int ret;1115 1116	switch (cap) {1117	case DP_LOCAL_CAP:1118	case DP_REMOTE_CAP:1119	case DP_COMMON_CAP:1120		break;1121 1122	default:1123		tb_tunnel_WARN(tunnel, "invalid capability index %#x\n", cap);1124		return -EINVAL;1125	}1126 1127	/*1128	 * Read from the copied remote cap so that we take into account1129	 * if capabilities were reduced during exchange.1130	 */1131	ret = tb_port_read(in, &val, TB_CFG_PORT, in->cap_adap + cap, 1);1132	if (ret)1133		return ret;1134 1135	*rate = tb_dp_cap_get_rate(val);1136	*lanes = tb_dp_cap_get_lanes(val);1137	return 0;1138}1139 1140static int tb_dp_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,1141				   int *max_down)1142{1143	int ret;1144 1145	if (!usb4_dp_port_bandwidth_mode_enabled(tunnel->src_port))1146		return -EOPNOTSUPP;1147 1148	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, NULL);1149	if (ret < 0)1150		return ret;1151 1152	if (tb_tunnel_direction_downstream(tunnel)) {1153		*max_up = 0;1154		*max_down = ret;1155	} else {1156		*max_up = ret;1157		*max_down = 0;1158	}1159 1160	return 0;1161}1162 1163static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,1164				    int *consumed_down)1165{1166	const struct tb_switch *sw = tunnel->src_port->sw;1167	u32 rate = 0, lanes = 0;1168	int ret;1169 1170	if (tb_dp_is_usb4(sw)) {1171		/*1172		 * On USB4 routers check if the bandwidth allocation1173		 * mode is enabled first and then read the bandwidth1174		 * through those registers.1175		 */1176		ret = tb_dp_bandwidth_mode_consumed_bandwidth(tunnel, consumed_up,1177							      consumed_down);1178		if (ret < 0) {1179			if (ret != -EOPNOTSUPP)1180				return ret;1181		} else if (!ret) {1182			return 0;1183		}1184		/*1185		 * Then see if the DPRX negotiation is ready and if yes1186		 * return that bandwidth (it may be smaller than the1187		 * reduced one). According to VESA spec, the DPRX1188		 * negotiation shall compete in 5 seconds after tunnel1189		 * established. We give it 100ms extra just in case.1190		 */1191		ret = tb_dp_wait_dprx(tunnel, 5100);1192		if (ret)1193			return ret;1194		ret = tb_dp_read_cap(tunnel, DP_COMMON_CAP, &rate, &lanes);1195		if (ret)1196			return ret;1197	} else if (sw->generation >= 2) {1198		ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP, &rate, &lanes);1199		if (ret)1200			return ret;1201	} else {1202		/* No bandwidth management for legacy devices  */1203		*consumed_up = 0;1204		*consumed_down = 0;1205		return 0;1206	}1207 1208	if (tb_tunnel_direction_downstream(tunnel)) {1209		*consumed_up = 0;1210		*consumed_down = tb_dp_bandwidth(rate, lanes);1211	} else {1212		*consumed_up = tb_dp_bandwidth(rate, lanes);1213		*consumed_down = 0;1214	}1215 1216	return 0;1217}1218 1219static void tb_dp_init_aux_credits(struct tb_path_hop *hop)1220{1221	struct tb_port *port = hop->in_port;1222	struct tb_switch *sw = port->sw;1223 1224	if (tb_port_use_credit_allocation(port))1225		hop->initial_credits = sw->min_dp_aux_credits;1226	else1227		hop->initial_credits = 1;1228}1229 1230static void tb_dp_init_aux_path(struct tb_path *path, bool pm_support)1231{1232	struct tb_path_hop *hop;1233 1234	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;1235	path->egress_shared_buffer = TB_PATH_NONE;1236	path->ingress_fc_enable = TB_PATH_ALL;1237	path->ingress_shared_buffer = TB_PATH_NONE;1238	path->priority = TB_DP_AUX_PRIORITY;1239	path->weight = TB_DP_AUX_WEIGHT;1240 1241	tb_path_for_each_hop(path, hop) {1242		tb_dp_init_aux_credits(hop);1243		if (pm_support)1244			tb_init_pm_support(hop);1245	}1246}1247 1248static int tb_dp_init_video_credits(struct tb_path_hop *hop)1249{1250	struct tb_port *port = hop->in_port;1251	struct tb_switch *sw = port->sw;1252 1253	if (tb_port_use_credit_allocation(port)) {1254		unsigned int nfc_credits;1255		size_t max_dp_streams;1256 1257		tb_available_credits(port, &max_dp_streams);1258		/*1259		 * Read the number of currently allocated NFC credits1260		 * from the lane adapter. Since we only use them for DP1261		 * tunneling we can use that to figure out how many DP1262		 * tunnels already go through the lane adapter.1263		 */1264		nfc_credits = port->config.nfc_credits &1265				ADP_CS_4_NFC_BUFFERS_MASK;1266		if (nfc_credits / sw->min_dp_main_credits > max_dp_streams)1267			return -ENOSPC;1268 1269		hop->nfc_credits = sw->min_dp_main_credits;1270	} else {1271		hop->nfc_credits = min(port->total_credits - 2, 12U);1272	}1273 1274	return 0;1275}1276 1277static int tb_dp_init_video_path(struct tb_path *path, bool pm_support)1278{1279	struct tb_path_hop *hop;1280 1281	path->egress_fc_enable = TB_PATH_NONE;1282	path->egress_shared_buffer = TB_PATH_NONE;1283	path->ingress_fc_enable = TB_PATH_NONE;1284	path->ingress_shared_buffer = TB_PATH_NONE;1285	path->priority = TB_DP_VIDEO_PRIORITY;1286	path->weight = TB_DP_VIDEO_WEIGHT;1287 1288	tb_path_for_each_hop(path, hop) {1289		int ret;1290 1291		ret = tb_dp_init_video_credits(hop);1292		if (ret)1293			return ret;1294		if (pm_support)1295			tb_init_pm_support(hop);1296	}1297 1298	return 0;1299}1300 1301static void tb_dp_dump(struct tb_tunnel *tunnel)1302{1303	struct tb_port *in, *out;1304	u32 dp_cap, rate, lanes;1305 1306	in = tunnel->src_port;1307	out = tunnel->dst_port;1308 1309	if (tb_port_read(in, &dp_cap, TB_CFG_PORT,1310			 in->cap_adap + DP_LOCAL_CAP, 1))1311		return;1312 1313	rate = tb_dp_cap_get_rate(dp_cap);1314	lanes = tb_dp_cap_get_lanes(dp_cap);1315 1316	tb_tunnel_dbg(tunnel,1317		      "DP IN maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",1318		      rate, lanes, tb_dp_bandwidth(rate, lanes));1319 1320	if (tb_port_read(out, &dp_cap, TB_CFG_PORT,1321			 out->cap_adap + DP_LOCAL_CAP, 1))1322		return;1323 1324	rate = tb_dp_cap_get_rate(dp_cap);1325	lanes = tb_dp_cap_get_lanes(dp_cap);1326 1327	tb_tunnel_dbg(tunnel,1328		      "DP OUT maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",1329		      rate, lanes, tb_dp_bandwidth(rate, lanes));1330 1331	if (tb_port_read(in, &dp_cap, TB_CFG_PORT,1332			 in->cap_adap + DP_REMOTE_CAP, 1))1333		return;1334 1335	rate = tb_dp_cap_get_rate(dp_cap);1336	lanes = tb_dp_cap_get_lanes(dp_cap);1337 1338	tb_tunnel_dbg(tunnel, "reduced bandwidth %u Mb/s x%u = %u Mb/s\n",1339		      rate, lanes, tb_dp_bandwidth(rate, lanes));1340}1341 1342/**1343 * tb_tunnel_discover_dp() - Discover existing Display Port tunnels1344 * @tb: Pointer to the domain structure1345 * @in: DP in adapter1346 * @alloc_hopid: Allocate HopIDs from visited ports1347 *1348 * If @in adapter is active, follows the tunnel to the DP out adapter1349 * and back. Returns the discovered tunnel or %NULL if there was no1350 * tunnel.1351 *1352 * Return: DP tunnel or %NULL if no tunnel found.1353 */1354struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,1355					bool alloc_hopid)1356{1357	struct tb_tunnel *tunnel;1358	struct tb_port *port;1359	struct tb_path *path;1360 1361	if (!tb_dp_port_is_enabled(in))1362		return NULL;1363 1364	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);1365	if (!tunnel)1366		return NULL;1367 1368	tunnel->init = tb_dp_init;1369	tunnel->deinit = tb_dp_deinit;1370	tunnel->activate = tb_dp_activate;1371	tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;1372	tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;1373	tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;1374	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;1375	tunnel->src_port = in;1376 1377	path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,1378				&tunnel->dst_port, "Video", alloc_hopid);1379	if (!path) {1380		/* Just disable the DP IN port */1381		tb_dp_port_enable(in, false);1382		goto err_free;1383	}1384	tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;1385	if (tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT], false))1386		goto err_free;1387 1388	path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX",1389				alloc_hopid);1390	if (!path)1391		goto err_deactivate;1392	tunnel->paths[TB_DP_AUX_PATH_OUT] = path;1393	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT], false);1394 1395	path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,1396				&port, "AUX RX", alloc_hopid);1397	if (!path)1398		goto err_deactivate;1399	tunnel->paths[TB_DP_AUX_PATH_IN] = path;1400	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN], false);1401 1402	/* Validate that the tunnel is complete */1403	if (!tb_port_is_dpout(tunnel->dst_port)) {1404		tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");1405		goto err_deactivate;1406	}1407 1408	if (!tb_dp_port_is_enabled(tunnel->dst_port))1409		goto err_deactivate;1410 1411	if (!tb_dp_port_hpd_is_active(tunnel->dst_port))1412		goto err_deactivate;1413 1414	if (port != tunnel->src_port) {1415		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");1416		goto err_deactivate;1417	}1418 1419	tb_dp_dump(tunnel);1420 1421	tb_tunnel_dbg(tunnel, "discovered\n");1422	return tunnel;1423 1424err_deactivate:1425	tb_tunnel_deactivate(tunnel);1426err_free:1427	tb_tunnel_free(tunnel);1428 1429	return NULL;1430}1431 1432/**1433 * tb_tunnel_alloc_dp() - allocate a Display Port tunnel1434 * @tb: Pointer to the domain structure1435 * @in: DP in adapter port1436 * @out: DP out adapter port1437 * @link_nr: Preferred lane adapter when the link is not bonded1438 * @max_up: Maximum available upstream bandwidth for the DP tunnel.1439 *	    %0 if no available bandwidth.1440 * @max_down: Maximum available downstream bandwidth for the DP tunnel.1441 *	      %0 if no available bandwidth.1442 *1443 * Allocates a tunnel between @in and @out that is capable of tunneling1444 * Display Port traffic.1445 *1446 * Return: Returns a tb_tunnel on success or NULL on failure.1447 */1448struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,1449				     struct tb_port *out, int link_nr,1450				     int max_up, int max_down)1451{1452	struct tb_tunnel *tunnel;1453	struct tb_path **paths;1454	struct tb_path *path;1455	bool pm_support;1456 1457	if (WARN_ON(!in->cap_adap || !out->cap_adap))1458		return NULL;1459 1460	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);1461	if (!tunnel)1462		return NULL;1463 1464	tunnel->init = tb_dp_init;1465	tunnel->deinit = tb_dp_deinit;1466	tunnel->activate = tb_dp_activate;1467	tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;1468	tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;1469	tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;1470	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;1471	tunnel->src_port = in;1472	tunnel->dst_port = out;1473	tunnel->max_up = max_up;1474	tunnel->max_down = max_down;1475 1476	paths = tunnel->paths;1477	pm_support = usb4_switch_version(in->sw) >= 2;1478 1479	path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,1480			     link_nr, "Video");1481	if (!path)1482		goto err_free;1483	tb_dp_init_video_path(path, pm_support);1484	paths[TB_DP_VIDEO_PATH_OUT] = path;1485 1486	path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,1487			     TB_DP_AUX_TX_HOPID, link_nr, "AUX TX");1488	if (!path)1489		goto err_free;1490	tb_dp_init_aux_path(path, pm_support);1491	paths[TB_DP_AUX_PATH_OUT] = path;1492 1493	path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,1494			     TB_DP_AUX_RX_HOPID, link_nr, "AUX RX");1495	if (!path)1496		goto err_free;1497	tb_dp_init_aux_path(path, pm_support);1498	paths[TB_DP_AUX_PATH_IN] = path;1499 1500	return tunnel;1501 1502err_free:1503	tb_tunnel_free(tunnel);1504	return NULL;1505}1506 1507static unsigned int tb_dma_available_credits(const struct tb_port *port)1508{1509	const struct tb_switch *sw = port->sw;1510	int credits;1511 1512	credits = tb_available_credits(port, NULL);1513	if (tb_acpi_may_tunnel_pcie())1514		credits -= sw->max_pcie_credits;1515	credits -= port->dma_credits;1516 1517	return credits > 0 ? credits : 0;1518}1519 1520static int tb_dma_reserve_credits(struct tb_path_hop *hop, unsigned int credits)1521{1522	struct tb_port *port = hop->in_port;1523 1524	if (tb_port_use_credit_allocation(port)) {1525		unsigned int available = tb_dma_available_credits(port);1526 1527		/*1528		 * Need to have at least TB_MIN_DMA_CREDITS, otherwise1529		 * DMA path cannot be established.1530		 */1531		if (available < TB_MIN_DMA_CREDITS)1532			return -ENOSPC;1533 1534		while (credits > available)1535			credits--;1536 1537		tb_port_dbg(port, "reserving %u credits for DMA path\n",1538			    credits);1539 1540		port->dma_credits += credits;1541	} else {1542		if (tb_port_is_null(port))1543			credits = port->bonded ? 14 : 6;1544		else1545			credits = min(port->total_credits, credits);1546	}1547 1548	hop->initial_credits = credits;1549	return 0;1550}1551 1552/* Path from lane adapter to NHI */1553static int tb_dma_init_rx_path(struct tb_path *path, unsigned int credits)1554{1555	struct tb_path_hop *hop;1556	unsigned int i, tmp;1557 1558	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;1559	path->ingress_fc_enable = TB_PATH_ALL;1560	path->egress_shared_buffer = TB_PATH_NONE;1561	path->ingress_shared_buffer = TB_PATH_NONE;1562	path->priority = TB_DMA_PRIORITY;1563	path->weight = TB_DMA_WEIGHT;1564	path->clear_fc = true;1565 1566	/*1567	 * First lane adapter is the one connected to the remote host.1568	 * We don't tunnel other traffic over this link so can use all1569	 * the credits (except the ones reserved for control traffic).1570	 */1571	hop = &path->hops[0];1572	tmp = min(tb_usable_credits(hop->in_port), credits);1573	hop->initial_credits = tmp;1574	hop->in_port->dma_credits += tmp;1575 1576	for (i = 1; i < path->path_length; i++) {1577		int ret;1578 1579		ret = tb_dma_reserve_credits(&path->hops[i], credits);1580		if (ret)1581			return ret;1582	}1583 1584	return 0;1585}1586 1587/* Path from NHI to lane adapter */1588static int tb_dma_init_tx_path(struct tb_path *path, unsigned int credits)1589{1590	struct tb_path_hop *hop;1591 1592	path->egress_fc_enable = TB_PATH_ALL;1593	path->ingress_fc_enable = TB_PATH_ALL;1594	path->egress_shared_buffer = TB_PATH_NONE;1595	path->ingress_shared_buffer = TB_PATH_NONE;1596	path->priority = TB_DMA_PRIORITY;1597	path->weight = TB_DMA_WEIGHT;1598	path->clear_fc = true;1599 1600	tb_path_for_each_hop(path, hop) {1601		int ret;1602 1603		ret = tb_dma_reserve_credits(hop, credits);1604		if (ret)1605			return ret;1606	}1607 1608	return 0;1609}1610 1611static void tb_dma_release_credits(struct tb_path_hop *hop)1612{1613	struct tb_port *port = hop->in_port;1614 1615	if (tb_port_use_credit_allocation(port)) {1616		port->dma_credits -= hop->initial_credits;1617 1618		tb_port_dbg(port, "released %u DMA path credits\n",1619			    hop->initial_credits);1620	}1621}1622 1623static void tb_dma_deinit_path(struct tb_path *path)1624{1625	struct tb_path_hop *hop;1626 1627	tb_path_for_each_hop(path, hop)1628		tb_dma_release_credits(hop);1629}1630 1631static void tb_dma_deinit(struct tb_tunnel *tunnel)1632{1633	int i;1634 1635	for (i = 0; i < tunnel->npaths; i++) {1636		if (!tunnel->paths[i])1637			continue;1638		tb_dma_deinit_path(tunnel->paths[i]);1639	}1640}1641 1642/**1643 * tb_tunnel_alloc_dma() - allocate a DMA tunnel1644 * @tb: Pointer to the domain structure1645 * @nhi: Host controller port1646 * @dst: Destination null port which the other domain is connected to1647 * @transmit_path: HopID used for transmitting packets1648 * @transmit_ring: NHI ring number used to send packets towards the1649 *		   other domain. Set to %-1 if TX path is not needed.1650 * @receive_path: HopID used for receiving packets1651 * @receive_ring: NHI ring number used to receive packets from the1652 *		  other domain. Set to %-1 if RX path is not needed.1653 *1654 * Return: Returns a tb_tunnel on success or NULL on failure.1655 */1656struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,1657				      struct tb_port *dst, int transmit_path,1658				      int transmit_ring, int receive_path,1659				      int receive_ring)1660{1661	struct tb_tunnel *tunnel;1662	size_t npaths = 0, i = 0;1663	struct tb_path *path;1664	int credits;1665 1666	/* Ring 0 is reserved for control channel */1667	if (WARN_ON(!receive_ring || !transmit_ring))1668		return NULL;1669 1670	if (receive_ring > 0)1671		npaths++;1672	if (transmit_ring > 0)1673		npaths++;1674 1675	if (WARN_ON(!npaths))1676		return NULL;1677 1678	tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);1679	if (!tunnel)1680		return NULL;1681 1682	tunnel->src_port = nhi;1683	tunnel->dst_port = dst;1684	tunnel->deinit = tb_dma_deinit;1685 1686	credits = min_not_zero(dma_credits, nhi->sw->max_dma_credits);1687 1688	if (receive_ring > 0) {1689		path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,1690				     "DMA RX");1691		if (!path)1692			goto err_free;1693		tunnel->paths[i++] = path;1694		if (tb_dma_init_rx_path(path, credits)) {1695			tb_tunnel_dbg(tunnel, "not enough buffers for RX path\n");1696			goto err_free;1697		}1698	}1699 1700	if (transmit_ring > 0) {1701		path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,1702				     "DMA TX");1703		if (!path)1704			goto err_free;1705		tunnel->paths[i++] = path;1706		if (tb_dma_init_tx_path(path, credits)) {1707			tb_tunnel_dbg(tunnel, "not enough buffers for TX path\n");1708			goto err_free;1709		}1710	}1711 1712	return tunnel;1713 1714err_free:1715	tb_tunnel_free(tunnel);1716	return NULL;1717}1718 1719/**1720 * tb_tunnel_match_dma() - Match DMA tunnel1721 * @tunnel: Tunnel to match1722 * @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.1723 * @transmit_ring: NHI ring number used to send packets towards the1724 *		   other domain. Pass %-1 to ignore.1725 * @receive_path: HopID used for receiving packets. Pass %-1 to ignore.1726 * @receive_ring: NHI ring number used to receive packets from the1727 *		  other domain. Pass %-1 to ignore.1728 *1729 * This function can be used to match specific DMA tunnel, if there are1730 * multiple DMA tunnels going through the same XDomain connection.1731 * Returns true if there is match and false otherwise.1732 */1733bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,1734			 int transmit_ring, int receive_path, int receive_ring)1735{1736	const struct tb_path *tx_path = NULL, *rx_path = NULL;1737	int i;1738 1739	if (!receive_ring || !transmit_ring)1740		return false;1741 1742	for (i = 0; i < tunnel->npaths; i++) {1743		const struct tb_path *path = tunnel->paths[i];1744 1745		if (!path)1746			continue;1747 1748		if (tb_port_is_nhi(path->hops[0].in_port))1749			tx_path = path;1750		else if (tb_port_is_nhi(path->hops[path->path_length - 1].out_port))1751			rx_path = path;1752	}1753 1754	if (transmit_ring > 0 || transmit_path > 0) {1755		if (!tx_path)1756			return false;1757		if (transmit_ring > 0 &&1758		    (tx_path->hops[0].in_hop_index != transmit_ring))1759			return false;1760		if (transmit_path > 0 &&1761		    (tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))1762			return false;1763	}1764 1765	if (receive_ring > 0 || receive_path > 0) {1766		if (!rx_path)1767			return false;1768		if (receive_path > 0 &&1769		    (rx_path->hops[0].in_hop_index != receive_path))1770			return false;1771		if (receive_ring > 0 &&1772		    (rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))1773			return false;1774	}1775 1776	return true;1777}1778 1779static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)1780{1781	int ret, up_max_rate, down_max_rate;1782 1783	ret = usb4_usb3_port_max_link_rate(up);1784	if (ret < 0)1785		return ret;1786	up_max_rate = ret;1787 1788	ret = usb4_usb3_port_max_link_rate(down);1789	if (ret < 0)1790		return ret;1791	down_max_rate = ret;1792 1793	return min(up_max_rate, down_max_rate);1794}1795 1796static int tb_usb3_init(struct tb_tunnel *tunnel)1797{1798	tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",1799		      tunnel->allocated_up, tunnel->allocated_down);1800 1801	return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,1802						 &tunnel->allocated_up,1803						 &tunnel->allocated_down);1804}1805 1806static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)1807{1808	int res;1809 1810	res = tb_usb3_port_enable(tunnel->src_port, activate);1811	if (res)1812		return res;1813 1814	if (tb_port_is_usb3_up(tunnel->dst_port))1815		return tb_usb3_port_enable(tunnel->dst_port, activate);1816 1817	return 0;1818}1819 1820static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,1821		int *consumed_up, int *consumed_down)1822{1823	struct tb_port *port = tb_upstream_port(tunnel->dst_port->sw);1824	int pcie_weight = tb_acpi_may_tunnel_pcie() ? TB_PCI_WEIGHT : 0;1825 1826	/*1827	 * PCIe tunneling, if enabled, affects the USB3 bandwidth so1828	 * take that it into account here.1829	 */1830	*consumed_up = tunnel->allocated_up *1831		(TB_USB3_WEIGHT + pcie_weight) / TB_USB3_WEIGHT;1832	*consumed_down = tunnel->allocated_down *1833		(TB_USB3_WEIGHT + pcie_weight) / TB_USB3_WEIGHT;1834 1835	if (tb_port_get_link_generation(port) >= 4) {1836		*consumed_up = max(*consumed_up, USB4_V2_USB3_MIN_BANDWIDTH);1837		*consumed_down = max(*consumed_down, USB4_V2_USB3_MIN_BANDWIDTH);1838	}1839 1840	return 0;1841}1842 1843static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)1844{1845	int ret;1846 1847	ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,1848					       &tunnel->allocated_up,1849					       &tunnel->allocated_down);1850	if (ret)1851		return ret;1852 1853	tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",1854		      tunnel->allocated_up, tunnel->allocated_down);1855	return 0;1856}1857 1858static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,1859						int *available_up,1860						int *available_down)1861{1862	int ret, max_rate, allocate_up, allocate_down;1863 1864	ret = tb_usb3_max_link_rate(tunnel->dst_port, tunnel->src_port);1865	if (ret < 0) {1866		tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");1867		return;1868	}1869 1870	/*1871	 * 90% of the max rate can be allocated for isochronous1872	 * transfers.1873	 */1874	max_rate = ret * 90 / 100;1875 1876	/* No need to reclaim if already at maximum */1877	if (tunnel->allocated_up >= max_rate &&1878	    tunnel->allocated_down >= max_rate)1879		return;1880 1881	/* Don't go lower than what is already allocated */1882	allocate_up = min(max_rate, *available_up);1883	if (allocate_up < tunnel->allocated_up)1884		allocate_up = tunnel->allocated_up;1885 1886	allocate_down = min(max_rate, *available_down);1887	if (allocate_down < tunnel->allocated_down)1888		allocate_down = tunnel->allocated_down;1889 1890	/* If no changes no need to do more */1891	if (allocate_up == tunnel->allocated_up &&1892	    allocate_down == tunnel->allocated_down)1893		return;1894 1895	ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,1896						&allocate_down);1897	if (ret) {1898		tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");1899		return;1900	}1901 1902	tunnel->allocated_up = allocate_up;1903	*available_up -= tunnel->allocated_up;1904 1905	tunnel->allocated_down = allocate_down;1906	*available_down -= tunnel->allocated_down;1907 1908	tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",1909		      tunnel->allocated_up, tunnel->allocated_down);1910}1911 1912static void tb_usb3_init_credits(struct tb_path_hop *hop)1913{1914	struct tb_port *port = hop->in_port;1915	struct tb_switch *sw = port->sw;1916	unsigned int credits;1917 1918	if (tb_port_use_credit_allocation(port)) {1919		credits = sw->max_usb3_credits;1920	} else {1921		if (tb_port_is_null(port))1922			credits = port->bonded ? 32 : 16;1923		else1924			credits = 7;1925	}1926 1927	hop->initial_credits = credits;1928}1929 1930static void tb_usb3_init_path(struct tb_path *path)1931{1932	struct tb_path_hop *hop;1933 1934	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;1935	path->egress_shared_buffer = TB_PATH_NONE;1936	path->ingress_fc_enable = TB_PATH_ALL;1937	path->ingress_shared_buffer = TB_PATH_NONE;1938	path->priority = TB_USB3_PRIORITY;1939	path->weight = TB_USB3_WEIGHT;1940	path->drop_packages = 0;1941 1942	tb_path_for_each_hop(path, hop)1943		tb_usb3_init_credits(hop);1944}1945 1946/**1947 * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels1948 * @tb: Pointer to the domain structure1949 * @down: USB3 downstream adapter1950 * @alloc_hopid: Allocate HopIDs from visited ports1951 *1952 * If @down adapter is active, follows the tunnel to the USB3 upstream1953 * adapter and back. Returns the discovered tunnel or %NULL if there was1954 * no tunnel.1955 */1956struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down,1957					  bool alloc_hopid)1958{1959	struct tb_tunnel *tunnel;1960	struct tb_path *path;1961 1962	if (!tb_usb3_port_is_enabled(down))1963		return NULL;1964 1965	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);1966	if (!tunnel)1967		return NULL;1968 1969	tunnel->activate = tb_usb3_activate;1970	tunnel->src_port = down;1971 1972	/*1973	 * Discover both paths even if they are not complete. We will1974	 * clean them up by calling tb_tunnel_deactivate() below in that1975	 * case.1976	 */1977	path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,1978				&tunnel->dst_port, "USB3 Down", alloc_hopid);1979	if (!path) {1980		/* Just disable the downstream port */1981		tb_usb3_port_enable(down, false);1982		goto err_free;1983	}1984	tunnel->paths[TB_USB3_PATH_DOWN] = path;1985	tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);1986 1987	path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,1988				"USB3 Up", alloc_hopid);1989	if (!path)1990		goto err_deactivate;1991	tunnel->paths[TB_USB3_PATH_UP] = path;1992	tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);1993 1994	/* Validate that the tunnel is complete */1995	if (!tb_port_is_usb3_up(tunnel->dst_port)) {1996		tb_port_warn(tunnel->dst_port,1997			     "path does not end on an USB3 adapter, cleaning up\n");1998		goto err_deactivate;1999	}2000 2001	if (down != tunnel->src_port) {2002		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");2003		goto err_deactivate;2004	}2005 2006	if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {2007		tb_tunnel_warn(tunnel,2008			       "tunnel is not fully activated, cleaning up\n");2009		goto err_deactivate;2010	}2011 2012	if (!tb_route(down->sw)) {2013		int ret;2014 2015		/*2016		 * Read the initial bandwidth allocation for the first2017		 * hop tunnel.2018		 */2019		ret = usb4_usb3_port_allocated_bandwidth(down,2020			&tunnel->allocated_up, &tunnel->allocated_down);2021		if (ret)2022			goto err_deactivate;2023 2024		tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",2025			      tunnel->allocated_up, tunnel->allocated_down);2026 2027		tunnel->init = tb_usb3_init;2028		tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;2029		tunnel->release_unused_bandwidth =2030			tb_usb3_release_unused_bandwidth;2031		tunnel->reclaim_available_bandwidth =2032			tb_usb3_reclaim_available_bandwidth;2033	}2034 2035	tb_tunnel_dbg(tunnel, "discovered\n");2036	return tunnel;2037 2038err_deactivate:2039	tb_tunnel_deactivate(tunnel);2040err_free:2041	tb_tunnel_free(tunnel);2042 2043	return NULL;2044}2045 2046/**2047 * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel2048 * @tb: Pointer to the domain structure2049 * @up: USB3 upstream adapter port2050 * @down: USB3 downstream adapter port2051 * @max_up: Maximum available upstream bandwidth for the USB3 tunnel.2052 *	    %0 if no available bandwidth.2053 * @max_down: Maximum available downstream bandwidth for the USB3 tunnel.2054 *	      %0 if no available bandwidth.2055 *2056 * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and2057 * @TB_TYPE_USB3_DOWN.2058 *2059 * Return: Returns a tb_tunnel on success or %NULL on failure.2060 */2061struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,2062				       struct tb_port *down, int max_up,2063				       int max_down)2064{2065	struct tb_tunnel *tunnel;2066	struct tb_path *path;2067	int max_rate = 0;2068 2069	if (!tb_route(down->sw) && (max_up > 0 || max_down > 0)) {2070		/*2071		 * For USB3 isochronous transfers, we allow bandwidth which is2072		 * not higher than 90% of maximum supported bandwidth by USB32073		 * adapters.2074		 */2075		max_rate = tb_usb3_max_link_rate(down, up);2076		if (max_rate < 0)2077			return NULL;2078 2079		max_rate = max_rate * 90 / 100;2080		tb_port_dbg(up, "maximum required bandwidth for USB3 tunnel %d Mb/s\n",2081			    max_rate);2082	}2083 2084	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);2085	if (!tunnel)2086		return NULL;2087 2088	tunnel->activate = tb_usb3_activate;2089	tunnel->src_port = down;2090	tunnel->dst_port = up;2091	tunnel->max_up = max_up;2092	tunnel->max_down = max_down;2093 2094	path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,2095			     "USB3 Down");2096	if (!path) {2097		tb_tunnel_free(tunnel);2098		return NULL;2099	}2100	tb_usb3_init_path(path);2101	tunnel->paths[TB_USB3_PATH_DOWN] = path;2102 2103	path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,2104			     "USB3 Up");2105	if (!path) {2106		tb_tunnel_free(tunnel);2107		return NULL;2108	}2109	tb_usb3_init_path(path);2110	tunnel->paths[TB_USB3_PATH_UP] = path;2111 2112	if (!tb_route(down->sw)) {2113		tunnel->allocated_up = min(max_rate, max_up);2114		tunnel->allocated_down = min(max_rate, max_down);2115 2116		tunnel->init = tb_usb3_init;2117		tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;2118		tunnel->release_unused_bandwidth =2119			tb_usb3_release_unused_bandwidth;2120		tunnel->reclaim_available_bandwidth =2121			tb_usb3_reclaim_available_bandwidth;2122	}2123 2124	return tunnel;2125}2126 2127/**2128 * tb_tunnel_free() - free a tunnel2129 * @tunnel: Tunnel to be freed2130 *2131 * Frees a tunnel. The tunnel does not need to be deactivated.2132 */2133void tb_tunnel_free(struct tb_tunnel *tunnel)2134{2135	int i;2136 2137	if (!tunnel)2138		return;2139 2140	if (tunnel->deinit)2141		tunnel->deinit(tunnel);2142 2143	for (i = 0; i < tunnel->npaths; i++) {2144		if (tunnel->paths[i])2145			tb_path_free(tunnel->paths[i]);2146	}2147 2148	kfree(tunnel->paths);2149	kfree(tunnel);2150}2151 2152/**2153 * tb_tunnel_is_invalid - check whether an activated path is still valid2154 * @tunnel: Tunnel to check2155 */2156bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)2157{2158	int i;2159 2160	for (i = 0; i < tunnel->npaths; i++) {2161		WARN_ON(!tunnel->paths[i]->activated);2162		if (tb_path_is_invalid(tunnel->paths[i]))2163			return true;2164	}2165 2166	return false;2167}2168 2169/**2170 * tb_tunnel_restart() - activate a tunnel after a hardware reset2171 * @tunnel: Tunnel to restart2172 *2173 * Return: 0 on success and negative errno in case if failure2174 */2175int tb_tunnel_restart(struct tb_tunnel *tunnel)2176{2177	int res, i;2178 2179	tb_tunnel_dbg(tunnel, "activating\n");2180 2181	/*2182	 * Make sure all paths are properly disabled before enabling2183	 * them again.2184	 */2185	for (i = 0; i < tunnel->npaths; i++) {2186		if (tunnel->paths[i]->activated) {2187			tb_path_deactivate(tunnel->paths[i]);2188			tunnel->paths[i]->activated = false;2189		}2190	}2191 2192	if (tunnel->init) {2193		res = tunnel->init(tunnel);2194		if (res)2195			return res;2196	}2197 2198	for (i = 0; i < tunnel->npaths; i++) {2199		res = tb_path_activate(tunnel->paths[i]);2200		if (res)2201			goto err;2202	}2203 2204	if (tunnel->activate) {2205		res = tunnel->activate(tunnel, true);2206		if (res)2207			goto err;2208	}2209 2210	return 0;2211 2212err:2213	tb_tunnel_warn(tunnel, "activation failed\n");2214	tb_tunnel_deactivate(tunnel);2215	return res;2216}2217 2218/**2219 * tb_tunnel_activate() - activate a tunnel2220 * @tunnel: Tunnel to activate2221 *2222 * Return: Returns 0 on success or an error code on failure.2223 */2224int tb_tunnel_activate(struct tb_tunnel *tunnel)2225{2226	int i;2227 2228	for (i = 0; i < tunnel->npaths; i++) {2229		if (tunnel->paths[i]->activated) {2230			tb_tunnel_WARN(tunnel,2231				       "trying to activate an already activated tunnel\n");2232			return -EINVAL;2233		}2234	}2235 2236	return tb_tunnel_restart(tunnel);2237}2238 2239/**2240 * tb_tunnel_deactivate() - deactivate a tunnel2241 * @tunnel: Tunnel to deactivate2242 */2243void tb_tunnel_deactivate(struct tb_tunnel *tunnel)2244{2245	int i;2246 2247	tb_tunnel_dbg(tunnel, "deactivating\n");2248 2249	if (tunnel->activate)2250		tunnel->activate(tunnel, false);2251 2252	for (i = 0; i < tunnel->npaths; i++) {2253		if (tunnel->paths[i] && tunnel->paths[i]->activated)2254			tb_path_deactivate(tunnel->paths[i]);2255	}2256}2257 2258/**2259 * tb_tunnel_port_on_path() - Does the tunnel go through port2260 * @tunnel: Tunnel to check2261 * @port: Port to check2262 *2263 * Returns true if @tunnel goes through @port (direction does not matter),2264 * false otherwise.2265 */2266bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,2267			    const struct tb_port *port)2268{2269	int i;2270 2271	for (i = 0; i < tunnel->npaths; i++) {2272		if (!tunnel->paths[i])2273			continue;2274 2275		if (tb_path_port_on_path(tunnel->paths[i], port))2276			return true;2277	}2278 2279	return false;2280}2281 2282static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)2283{2284	int i;2285 2286	for (i = 0; i < tunnel->npaths; i++) {2287		if (!tunnel->paths[i])2288			return false;2289		if (!tunnel->paths[i]->activated)2290			return false;2291	}2292 2293	return true;2294}2295 2296/**2297 * tb_tunnel_maximum_bandwidth() - Return maximum possible bandwidth2298 * @tunnel: Tunnel to check2299 * @max_up: Maximum upstream bandwidth in Mb/s2300 * @max_down: Maximum downstream bandwidth in Mb/s2301 *2302 * Returns maximum possible bandwidth this tunnel can go if not limited2303 * by other bandwidth clients. If the tunnel does not support this2304 * returns %-EOPNOTSUPP.2305 */2306int tb_tunnel_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,2307				int *max_down)2308{2309	if (!tb_tunnel_is_active(tunnel))2310		return -EINVAL;2311 2312	if (tunnel->maximum_bandwidth)2313		return tunnel->maximum_bandwidth(tunnel, max_up, max_down);2314	return -EOPNOTSUPP;2315}2316 2317/**2318 * tb_tunnel_allocated_bandwidth() - Return bandwidth allocated for the tunnel2319 * @tunnel: Tunnel to check2320 * @allocated_up: Currently allocated upstream bandwidth in Mb/s is stored here2321 * @allocated_down: Currently allocated downstream bandwidth in Mb/s is2322 *		    stored here2323 *2324 * Returns the bandwidth allocated for the tunnel. This may be higher2325 * than what the tunnel actually consumes.2326 */2327int tb_tunnel_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,2328				  int *allocated_down)2329{2330	if (!tb_tunnel_is_active(tunnel))2331		return -EINVAL;2332 2333	if (tunnel->allocated_bandwidth)2334		return tunnel->allocated_bandwidth(tunnel, allocated_up,2335						   allocated_down);2336	return -EOPNOTSUPP;2337}2338 2339/**2340 * tb_tunnel_alloc_bandwidth() - Change tunnel bandwidth allocation2341 * @tunnel: Tunnel whose bandwidth allocation to change2342 * @alloc_up: New upstream bandwidth in Mb/s2343 * @alloc_down: New downstream bandwidth in Mb/s2344 *2345 * Tries to change tunnel bandwidth allocation. If succeeds returns %02346 * and updates @alloc_up and @alloc_down to that was actually allocated2347 * (it may not be the same as passed originally). Returns negative errno2348 * in case of failure.2349 */2350int tb_tunnel_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,2351			      int *alloc_down)2352{2353	if (!tb_tunnel_is_active(tunnel))2354		return -EINVAL;2355 2356	if (tunnel->alloc_bandwidth)2357		return tunnel->alloc_bandwidth(tunnel, alloc_up, alloc_down);2358 2359	return -EOPNOTSUPP;2360}2361 2362/**2363 * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel2364 * @tunnel: Tunnel to check2365 * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.2366 *		 Can be %NULL.2367 * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.2368 *		   Can be %NULL.2369 *2370 * Stores the amount of isochronous bandwidth @tunnel consumes in2371 * @consumed_up and @consumed_down. In case of success returns %0,2372 * negative errno otherwise.2373 */2374int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,2375				 int *consumed_down)2376{2377	int up_bw = 0, down_bw = 0;2378 2379	if (!tb_tunnel_is_active(tunnel))2380		goto out;2381 2382	if (tunnel->consumed_bandwidth) {2383		int ret;2384 2385		ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);2386		if (ret)2387			return ret;2388 2389		tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,2390			      down_bw);2391	}2392 2393out:2394	if (consumed_up)2395		*consumed_up = up_bw;2396	if (consumed_down)2397		*consumed_down = down_bw;2398 2399	return 0;2400}2401 2402/**2403 * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth2404 * @tunnel: Tunnel whose unused bandwidth to release2405 *2406 * If tunnel supports dynamic bandwidth management (USB3 tunnels at the2407 * moment) this function makes it to release all the unused bandwidth.2408 *2409 * Returns %0 in case of success and negative errno otherwise.2410 */2411int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)2412{2413	if (!tb_tunnel_is_active(tunnel))2414		return 0;2415 2416	if (tunnel->release_unused_bandwidth) {2417		int ret;2418 2419		ret = tunnel->release_unused_bandwidth(tunnel);2420		if (ret)2421			return ret;2422	}2423 2424	return 0;2425}2426 2427/**2428 * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth2429 * @tunnel: Tunnel reclaiming available bandwidth2430 * @available_up: Available upstream bandwidth (in Mb/s)2431 * @available_down: Available downstream bandwidth (in Mb/s)2432 *2433 * Reclaims bandwidth from @available_up and @available_down and updates2434 * the variables accordingly (e.g decreases both according to what was2435 * reclaimed by the tunnel). If nothing was reclaimed the values are2436 * kept as is.2437 */2438void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,2439					   int *available_up,2440					   int *available_down)2441{2442	if (!tb_tunnel_is_active(tunnel))2443		return;2444 2445	if (tunnel->reclaim_available_bandwidth)2446		tunnel->reclaim_available_bandwidth(tunnel, available_up,2447						    available_down);2448}2449 2450const char *tb_tunnel_type_name(const struct tb_tunnel *tunnel)2451{2452	return tb_tunnel_names[tunnel->type];2453}2454