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1// SPDX-License-Identifier: GPL-2.02/*3 * Thunderbolt driver - control channel and configuration commands4 *5 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>6 * Copyright (C) 2018, Intel Corporation7 */8 9#include <linux/crc32.h>10#include <linux/delay.h>11#include <linux/slab.h>12#include <linux/pci.h>13#include <linux/dmapool.h>14#include <linux/workqueue.h>15 16#include "ctl.h"17 18#define CREATE_TRACE_POINTS19#include "trace.h"20 21#define TB_CTL_RX_PKG_COUNT	1022#define TB_CTL_RETRIES		423 24/**25 * struct tb_ctl - Thunderbolt control channel26 * @nhi: Pointer to the NHI structure27 * @tx: Transmit ring28 * @rx: Receive ring29 * @frame_pool: DMA pool for control messages30 * @rx_packets: Received control messages31 * @request_queue_lock: Lock protecting @request_queue32 * @request_queue: List of outstanding requests33 * @running: Is the control channel running at the moment34 * @timeout_msec: Default timeout for non-raw control messages35 * @callback: Callback called when hotplug message is received36 * @callback_data: Data passed to @callback37 * @index: Domain number. This will be output with the trace record.38 */39struct tb_ctl {40	struct tb_nhi *nhi;41	struct tb_ring *tx;42	struct tb_ring *rx;43 44	struct dma_pool *frame_pool;45	struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT];46	struct mutex request_queue_lock;47	struct list_head request_queue;48	bool running;49 50	int timeout_msec;51	event_cb callback;52	void *callback_data;53 54	int index;55};56 57 58#define tb_ctl_WARN(ctl, format, arg...) \59	dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg)60 61#define tb_ctl_err(ctl, format, arg...) \62	dev_err(&(ctl)->nhi->pdev->dev, format, ## arg)63 64#define tb_ctl_warn(ctl, format, arg...) \65	dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg)66 67#define tb_ctl_info(ctl, format, arg...) \68	dev_info(&(ctl)->nhi->pdev->dev, format, ## arg)69 70#define tb_ctl_dbg(ctl, format, arg...) \71	dev_dbg(&(ctl)->nhi->pdev->dev, format, ## arg)72 73static DECLARE_WAIT_QUEUE_HEAD(tb_cfg_request_cancel_queue);74/* Serializes access to request kref_get/put */75static DEFINE_MUTEX(tb_cfg_request_lock);76 77/**78 * tb_cfg_request_alloc() - Allocates a new config request79 *80 * This is refcounted object so when you are done with this, call81 * tb_cfg_request_put() to it.82 */83struct tb_cfg_request *tb_cfg_request_alloc(void)84{85	struct tb_cfg_request *req;86 87	req = kzalloc(sizeof(*req), GFP_KERNEL);88	if (!req)89		return NULL;90 91	kref_init(&req->kref);92 93	return req;94}95 96/**97 * tb_cfg_request_get() - Increase refcount of a request98 * @req: Request whose refcount is increased99 */100void tb_cfg_request_get(struct tb_cfg_request *req)101{102	mutex_lock(&tb_cfg_request_lock);103	kref_get(&req->kref);104	mutex_unlock(&tb_cfg_request_lock);105}106 107static void tb_cfg_request_destroy(struct kref *kref)108{109	struct tb_cfg_request *req = container_of(kref, typeof(*req), kref);110 111	kfree(req);112}113 114/**115 * tb_cfg_request_put() - Decrease refcount and possibly release the request116 * @req: Request whose refcount is decreased117 *118 * Call this function when you are done with the request. When refcount119 * goes to %0 the object is released.120 */121void tb_cfg_request_put(struct tb_cfg_request *req)122{123	mutex_lock(&tb_cfg_request_lock);124	kref_put(&req->kref, tb_cfg_request_destroy);125	mutex_unlock(&tb_cfg_request_lock);126}127 128static int tb_cfg_request_enqueue(struct tb_ctl *ctl,129				  struct tb_cfg_request *req)130{131	WARN_ON(test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags));132	WARN_ON(req->ctl);133 134	mutex_lock(&ctl->request_queue_lock);135	if (!ctl->running) {136		mutex_unlock(&ctl->request_queue_lock);137		return -ENOTCONN;138	}139	req->ctl = ctl;140	list_add_tail(&req->list, &ctl->request_queue);141	set_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);142	mutex_unlock(&ctl->request_queue_lock);143	return 0;144}145 146static void tb_cfg_request_dequeue(struct tb_cfg_request *req)147{148	struct tb_ctl *ctl = req->ctl;149 150	mutex_lock(&ctl->request_queue_lock);151	list_del(&req->list);152	clear_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);153	if (test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))154		wake_up(&tb_cfg_request_cancel_queue);155	mutex_unlock(&ctl->request_queue_lock);156}157 158static bool tb_cfg_request_is_active(struct tb_cfg_request *req)159{160	return test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);161}162 163static struct tb_cfg_request *164tb_cfg_request_find(struct tb_ctl *ctl, struct ctl_pkg *pkg)165{166	struct tb_cfg_request *req = NULL, *iter;167 168	mutex_lock(&pkg->ctl->request_queue_lock);169	list_for_each_entry(iter, &pkg->ctl->request_queue, list) {170		tb_cfg_request_get(iter);171		if (iter->match(iter, pkg)) {172			req = iter;173			break;174		}175		tb_cfg_request_put(iter);176	}177	mutex_unlock(&pkg->ctl->request_queue_lock);178 179	return req;180}181 182/* utility functions */183 184 185static int check_header(const struct ctl_pkg *pkg, u32 len,186			enum tb_cfg_pkg_type type, u64 route)187{188	struct tb_cfg_header *header = pkg->buffer;189 190	/* check frame, TODO: frame flags */191	if (WARN(len != pkg->frame.size,192			"wrong framesize (expected %#x, got %#x)\n",193			len, pkg->frame.size))194		return -EIO;195	if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n",196			type, pkg->frame.eof))197		return -EIO;198	if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n",199			pkg->frame.sof))200		return -EIO;201 202	/* check header */203	if (WARN(header->unknown != 1 << 9,204			"header->unknown is %#x\n", header->unknown))205		return -EIO;206	if (WARN(route != tb_cfg_get_route(header),207			"wrong route (expected %llx, got %llx)",208			route, tb_cfg_get_route(header)))209		return -EIO;210	return 0;211}212 213static int check_config_address(struct tb_cfg_address addr,214				enum tb_cfg_space space, u32 offset,215				u32 length)216{217	if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero))218		return -EIO;219	if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)",220			space, addr.space))221		return -EIO;222	if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)",223			offset, addr.offset))224		return -EIO;225	if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)",226			length, addr.length))227		return -EIO;228	/*229	 * We cannot check addr->port as it is set to the upstream port of the230	 * sender.231	 */232	return 0;233}234 235static struct tb_cfg_result decode_error(const struct ctl_pkg *response)236{237	struct cfg_error_pkg *pkg = response->buffer;238	struct tb_cfg_result res = { 0 };239	res.response_route = tb_cfg_get_route(&pkg->header);240	res.response_port = 0;241	res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR,242			       tb_cfg_get_route(&pkg->header));243	if (res.err)244		return res;245 246	res.err = 1;247	res.tb_error = pkg->error;248	res.response_port = pkg->port;249	return res;250 251}252 253static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len,254					 enum tb_cfg_pkg_type type, u64 route)255{256	struct tb_cfg_header *header = pkg->buffer;257	struct tb_cfg_result res = { 0 };258 259	if (pkg->frame.eof == TB_CFG_PKG_ERROR)260		return decode_error(pkg);261 262	res.response_port = 0; /* will be updated later for cfg_read/write */263	res.response_route = tb_cfg_get_route(header);264	res.err = check_header(pkg, len, type, route);265	return res;266}267 268static void tb_cfg_print_error(struct tb_ctl *ctl,269			       const struct tb_cfg_result *res)270{271	WARN_ON(res->err != 1);272	switch (res->tb_error) {273	case TB_CFG_ERROR_PORT_NOT_CONNECTED:274		/* Port is not connected. This can happen during surprise275		 * removal. Do not warn. */276		return;277	case TB_CFG_ERROR_INVALID_CONFIG_SPACE:278		/*279		 * Invalid cfg_space/offset/length combination in280		 * cfg_read/cfg_write.281		 */282		tb_ctl_dbg(ctl, "%llx:%x: invalid config space or offset\n",283			   res->response_route, res->response_port);284		return;285	case TB_CFG_ERROR_NO_SUCH_PORT:286		/*287		 * - The route contains a non-existent port.288		 * - The route contains a non-PHY port (e.g. PCIe).289		 * - The port in cfg_read/cfg_write does not exist.290		 */291		tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",292			res->response_route, res->response_port);293		return;294	case TB_CFG_ERROR_LOOP:295		tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",296			res->response_route, res->response_port);297		return;298	case TB_CFG_ERROR_LOCK:299		tb_ctl_warn(ctl, "%llx:%x: downstream port is locked\n",300			    res->response_route, res->response_port);301		return;302	default:303		/* 5,6,7,9 and 11 are also valid error codes */304		tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",305			res->response_route, res->response_port);306		return;307	}308}309 310static __be32 tb_crc(const void *data, size_t len)311{312	return cpu_to_be32(~__crc32c_le(~0, data, len));313}314 315static void tb_ctl_pkg_free(struct ctl_pkg *pkg)316{317	if (pkg) {318		dma_pool_free(pkg->ctl->frame_pool,319			      pkg->buffer, pkg->frame.buffer_phy);320		kfree(pkg);321	}322}323 324static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl)325{326	struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL);327	if (!pkg)328		return NULL;329	pkg->ctl = ctl;330	pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL,331				     &pkg->frame.buffer_phy);332	if (!pkg->buffer) {333		kfree(pkg);334		return NULL;335	}336	return pkg;337}338 339 340/* RX/TX handling */341 342static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,343			       bool canceled)344{345	struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);346	tb_ctl_pkg_free(pkg);347}348 349/*350 * tb_cfg_tx() - transmit a packet on the control channel351 *352 * len must be a multiple of four.353 *354 * Return: Returns 0 on success or an error code on failure.355 */356static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len,357		     enum tb_cfg_pkg_type type)358{359	int res;360	struct ctl_pkg *pkg;361	if (len % 4 != 0) { /* required for le->be conversion */362		tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);363		return -EINVAL;364	}365	if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */366		tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",367			    len, TB_FRAME_SIZE - 4);368		return -EINVAL;369	}370	pkg = tb_ctl_pkg_alloc(ctl);371	if (!pkg)372		return -ENOMEM;373	pkg->frame.callback = tb_ctl_tx_callback;374	pkg->frame.size = len + 4;375	pkg->frame.sof = type;376	pkg->frame.eof = type;377 378	trace_tb_tx(ctl->index, type, data, len);379 380	cpu_to_be32_array(pkg->buffer, data, len / 4);381	*(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len);382 383	res = tb_ring_tx(ctl->tx, &pkg->frame);384	if (res) /* ring is stopped */385		tb_ctl_pkg_free(pkg);386	return res;387}388 389/*390 * tb_ctl_handle_event() - acknowledge a plug event, invoke ctl->callback391 */392static bool tb_ctl_handle_event(struct tb_ctl *ctl, enum tb_cfg_pkg_type type,393				struct ctl_pkg *pkg, size_t size)394{395	trace_tb_event(ctl->index, type, pkg->buffer, size);396	return ctl->callback(ctl->callback_data, type, pkg->buffer, size);397}398 399static void tb_ctl_rx_submit(struct ctl_pkg *pkg)400{401	tb_ring_rx(pkg->ctl->rx, &pkg->frame); /*402					     * We ignore failures during stop.403					     * All rx packets are referenced404					     * from ctl->rx_packets, so we do405					     * not loose them.406					     */407}408 409static int tb_async_error(const struct ctl_pkg *pkg)410{411	const struct cfg_error_pkg *error = pkg->buffer;412 413	if (pkg->frame.eof != TB_CFG_PKG_ERROR)414		return false;415 416	switch (error->error) {417	case TB_CFG_ERROR_LINK_ERROR:418	case TB_CFG_ERROR_HEC_ERROR_DETECTED:419	case TB_CFG_ERROR_FLOW_CONTROL_ERROR:420	case TB_CFG_ERROR_DP_BW:421	case TB_CFG_ERROR_ROP_CMPLT:422	case TB_CFG_ERROR_POP_CMPLT:423	case TB_CFG_ERROR_PCIE_WAKE:424	case TB_CFG_ERROR_DP_CON_CHANGE:425	case TB_CFG_ERROR_DPTX_DISCOVERY:426	case TB_CFG_ERROR_LINK_RECOVERY:427	case TB_CFG_ERROR_ASYM_LINK:428		return true;429 430	default:431		return false;432	}433}434 435static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,436			       bool canceled)437{438	struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);439	struct tb_cfg_request *req;440	__be32 crc32;441 442	if (canceled)443		return; /*444			 * ring is stopped, packet is referenced from445			 * ctl->rx_packets.446			 */447 448	if (frame->size < 4 || frame->size % 4 != 0) {449		tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",450			   frame->size);451		goto rx;452	}453 454	frame->size -= 4; /* remove checksum */455	crc32 = tb_crc(pkg->buffer, frame->size);456	be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);457 458	switch (frame->eof) {459	case TB_CFG_PKG_READ:460	case TB_CFG_PKG_WRITE:461	case TB_CFG_PKG_ERROR:462	case TB_CFG_PKG_OVERRIDE:463	case TB_CFG_PKG_RESET:464		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {465			tb_ctl_err(pkg->ctl,466				   "RX: checksum mismatch, dropping packet\n");467			goto rx;468		}469		if (tb_async_error(pkg)) {470			tb_ctl_handle_event(pkg->ctl, frame->eof,471					    pkg, frame->size);472			goto rx;473		}474		break;475 476	case TB_CFG_PKG_EVENT:477	case TB_CFG_PKG_XDOMAIN_RESP:478	case TB_CFG_PKG_XDOMAIN_REQ:479		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {480			tb_ctl_err(pkg->ctl,481				   "RX: checksum mismatch, dropping packet\n");482			goto rx;483		}484		fallthrough;485	case TB_CFG_PKG_ICM_EVENT:486		if (tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size))487			goto rx;488		break;489 490	default:491		break;492	}493 494	/*495	 * The received packet will be processed only if there is an496	 * active request and that the packet is what is expected. This497	 * prevents packets such as replies coming after timeout has498	 * triggered from messing with the active requests.499	 */500	req = tb_cfg_request_find(pkg->ctl, pkg);501 502	trace_tb_rx(pkg->ctl->index, frame->eof, pkg->buffer, frame->size, !req);503 504	if (req) {505		if (req->copy(req, pkg))506			schedule_work(&req->work);507		tb_cfg_request_put(req);508	}509 510rx:511	tb_ctl_rx_submit(pkg);512}513 514static void tb_cfg_request_work(struct work_struct *work)515{516	struct tb_cfg_request *req = container_of(work, typeof(*req), work);517 518	if (!test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))519		req->callback(req->callback_data);520 521	tb_cfg_request_dequeue(req);522	tb_cfg_request_put(req);523}524 525/**526 * tb_cfg_request() - Start control request not waiting for it to complete527 * @ctl: Control channel to use528 * @req: Request to start529 * @callback: Callback called when the request is completed530 * @callback_data: Data to be passed to @callback531 *532 * This queues @req on the given control channel without waiting for it533 * to complete. When the request completes @callback is called.534 */535int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req,536		   void (*callback)(void *), void *callback_data)537{538	int ret;539 540	req->flags = 0;541	req->callback = callback;542	req->callback_data = callback_data;543	INIT_WORK(&req->work, tb_cfg_request_work);544	INIT_LIST_HEAD(&req->list);545 546	tb_cfg_request_get(req);547	ret = tb_cfg_request_enqueue(ctl, req);548	if (ret)549		goto err_put;550 551	ret = tb_ctl_tx(ctl, req->request, req->request_size,552			req->request_type);553	if (ret)554		goto err_dequeue;555 556	if (!req->response)557		schedule_work(&req->work);558 559	return 0;560 561err_dequeue:562	tb_cfg_request_dequeue(req);563err_put:564	tb_cfg_request_put(req);565 566	return ret;567}568 569/**570 * tb_cfg_request_cancel() - Cancel a control request571 * @req: Request to cancel572 * @err: Error to assign to the request573 *574 * This function can be used to cancel ongoing request. It will wait575 * until the request is not active anymore.576 */577void tb_cfg_request_cancel(struct tb_cfg_request *req, int err)578{579	set_bit(TB_CFG_REQUEST_CANCELED, &req->flags);580	schedule_work(&req->work);581	wait_event(tb_cfg_request_cancel_queue, !tb_cfg_request_is_active(req));582	req->result.err = err;583}584 585static void tb_cfg_request_complete(void *data)586{587	complete(data);588}589 590/**591 * tb_cfg_request_sync() - Start control request and wait until it completes592 * @ctl: Control channel to use593 * @req: Request to start594 * @timeout_msec: Timeout how long to wait @req to complete595 *596 * Starts a control request and waits until it completes. If timeout597 * triggers the request is canceled before function returns. Note the598 * caller needs to make sure only one message for given switch is active599 * at a time.600 */601struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl,602					 struct tb_cfg_request *req,603					 int timeout_msec)604{605	unsigned long timeout = msecs_to_jiffies(timeout_msec);606	struct tb_cfg_result res = { 0 };607	DECLARE_COMPLETION_ONSTACK(done);608	int ret;609 610	ret = tb_cfg_request(ctl, req, tb_cfg_request_complete, &done);611	if (ret) {612		res.err = ret;613		return res;614	}615 616	if (!wait_for_completion_timeout(&done, timeout))617		tb_cfg_request_cancel(req, -ETIMEDOUT);618 619	flush_work(&req->work);620 621	return req->result;622}623 624/* public interface, alloc/start/stop/free */625 626/**627 * tb_ctl_alloc() - allocate a control channel628 * @nhi: Pointer to NHI629 * @index: Domain number630 * @timeout_msec: Default timeout used with non-raw control messages631 * @cb: Callback called for plug events632 * @cb_data: Data passed to @cb633 *634 * cb will be invoked once for every hot plug event.635 *636 * Return: Returns a pointer on success or NULL on failure.637 */638struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int index, int timeout_msec,639			    event_cb cb, void *cb_data)640{641	int i;642	struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);643	if (!ctl)644		return NULL;645 646	ctl->nhi = nhi;647	ctl->index = index;648	ctl->timeout_msec = timeout_msec;649	ctl->callback = cb;650	ctl->callback_data = cb_data;651 652	mutex_init(&ctl->request_queue_lock);653	INIT_LIST_HEAD(&ctl->request_queue);654	ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev,655					 TB_FRAME_SIZE, 4, 0);656	if (!ctl->frame_pool)657		goto err;658 659	ctl->tx = tb_ring_alloc_tx(nhi, 0, 10, RING_FLAG_NO_SUSPEND);660	if (!ctl->tx)661		goto err;662 663	ctl->rx = tb_ring_alloc_rx(nhi, 0, 10, RING_FLAG_NO_SUSPEND, 0, 0xffff,664				   0xffff, NULL, NULL);665	if (!ctl->rx)666		goto err;667 668	for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) {669		ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl);670		if (!ctl->rx_packets[i])671			goto err;672		ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback;673	}674 675	tb_ctl_dbg(ctl, "control channel created\n");676	return ctl;677err:678	tb_ctl_free(ctl);679	return NULL;680}681 682/**683 * tb_ctl_free() - free a control channel684 * @ctl: Control channel to free685 *686 * Must be called after tb_ctl_stop.687 *688 * Must NOT be called from ctl->callback.689 */690void tb_ctl_free(struct tb_ctl *ctl)691{692	int i;693 694	if (!ctl)695		return;696 697	if (ctl->rx)698		tb_ring_free(ctl->rx);699	if (ctl->tx)700		tb_ring_free(ctl->tx);701 702	/* free RX packets */703	for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)704		tb_ctl_pkg_free(ctl->rx_packets[i]);705 706 707	dma_pool_destroy(ctl->frame_pool);708	kfree(ctl);709}710 711/**712 * tb_ctl_start() - start/resume the control channel713 * @ctl: Control channel to start714 */715void tb_ctl_start(struct tb_ctl *ctl)716{717	int i;718	tb_ctl_dbg(ctl, "control channel starting...\n");719	tb_ring_start(ctl->tx); /* is used to ack hotplug packets, start first */720	tb_ring_start(ctl->rx);721	for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)722		tb_ctl_rx_submit(ctl->rx_packets[i]);723 724	ctl->running = true;725}726 727/**728 * tb_ctl_stop() - pause the control channel729 * @ctl: Control channel to stop730 *731 * All invocations of ctl->callback will have finished after this method732 * returns.733 *734 * Must NOT be called from ctl->callback.735 */736void tb_ctl_stop(struct tb_ctl *ctl)737{738	mutex_lock(&ctl->request_queue_lock);739	ctl->running = false;740	mutex_unlock(&ctl->request_queue_lock);741 742	tb_ring_stop(ctl->rx);743	tb_ring_stop(ctl->tx);744 745	if (!list_empty(&ctl->request_queue))746		tb_ctl_WARN(ctl, "dangling request in request_queue\n");747	INIT_LIST_HEAD(&ctl->request_queue);748	tb_ctl_dbg(ctl, "control channel stopped\n");749}750 751/* public interface, commands */752 753/**754 * tb_cfg_ack_notification() - Ack notification755 * @ctl: Control channel to use756 * @route: Router that originated the event757 * @error: Pointer to the notification package758 *759 * Call this as response for non-plug notification to ack it. Returns760 * %0 on success or an error code on failure.761 */762int tb_cfg_ack_notification(struct tb_ctl *ctl, u64 route,763			    const struct cfg_error_pkg *error)764{765	struct cfg_ack_pkg pkg = {766		.header = tb_cfg_make_header(route),767	};768	const char *name;769 770	switch (error->error) {771	case TB_CFG_ERROR_LINK_ERROR:772		name = "link error";773		break;774	case TB_CFG_ERROR_HEC_ERROR_DETECTED:775		name = "HEC error";776		break;777	case TB_CFG_ERROR_FLOW_CONTROL_ERROR:778		name = "flow control error";779		break;780	case TB_CFG_ERROR_DP_BW:781		name = "DP_BW";782		break;783	case TB_CFG_ERROR_ROP_CMPLT:784		name = "router operation completion";785		break;786	case TB_CFG_ERROR_POP_CMPLT:787		name = "port operation completion";788		break;789	case TB_CFG_ERROR_PCIE_WAKE:790		name = "PCIe wake";791		break;792	case TB_CFG_ERROR_DP_CON_CHANGE:793		name = "DP connector change";794		break;795	case TB_CFG_ERROR_DPTX_DISCOVERY:796		name = "DPTX discovery";797		break;798	case TB_CFG_ERROR_LINK_RECOVERY:799		name = "link recovery";800		break;801	case TB_CFG_ERROR_ASYM_LINK:802		name = "asymmetric link";803		break;804	default:805		name = "unknown";806		break;807	}808 809	tb_ctl_dbg(ctl, "acking %s (%#x) notification on %llx\n", name,810		   error->error, route);811 812	return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_NOTIFY_ACK);813}814 815/**816 * tb_cfg_ack_plug() - Ack hot plug/unplug event817 * @ctl: Control channel to use818 * @route: Router that originated the event819 * @port: Port where the hot plug/unplug happened820 * @unplug: Ack hot plug or unplug821 *822 * Call this as response for hot plug/unplug event to ack it.823 * Returns %0 on success or an error code on failure.824 */825int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug)826{827	struct cfg_error_pkg pkg = {828		.header = tb_cfg_make_header(route),829		.port = port,830		.error = TB_CFG_ERROR_ACK_PLUG_EVENT,831		.pg = unplug ? TB_CFG_ERROR_PG_HOT_UNPLUG832			     : TB_CFG_ERROR_PG_HOT_PLUG,833	};834	tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%u\n",835		   unplug ? "un" : "", route, port);836	return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);837}838 839static bool tb_cfg_match(const struct tb_cfg_request *req,840			 const struct ctl_pkg *pkg)841{842	u64 route = tb_cfg_get_route(pkg->buffer) & ~BIT_ULL(63);843 844	if (pkg->frame.eof == TB_CFG_PKG_ERROR)845		return true;846 847	if (pkg->frame.eof != req->response_type)848		return false;849	if (route != tb_cfg_get_route(req->request))850		return false;851	if (pkg->frame.size != req->response_size)852		return false;853 854	if (pkg->frame.eof == TB_CFG_PKG_READ ||855	    pkg->frame.eof == TB_CFG_PKG_WRITE) {856		const struct cfg_read_pkg *req_hdr = req->request;857		const struct cfg_read_pkg *res_hdr = pkg->buffer;858 859		if (req_hdr->addr.seq != res_hdr->addr.seq)860			return false;861	}862 863	return true;864}865 866static bool tb_cfg_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg)867{868	struct tb_cfg_result res;869 870	/* Now make sure it is in expected format */871	res = parse_header(pkg, req->response_size, req->response_type,872			   tb_cfg_get_route(req->request));873	if (!res.err)874		memcpy(req->response, pkg->buffer, req->response_size);875 876	req->result = res;877 878	/* Always complete when first response is received */879	return true;880}881 882/**883 * tb_cfg_reset() - send a reset packet and wait for a response884 * @ctl: Control channel pointer885 * @route: Router string for the router to send reset886 *887 * If the switch at route is incorrectly configured then we will not receive a888 * reply (even though the switch will reset). The caller should check for889 * -ETIMEDOUT and attempt to reconfigure the switch.890 */891struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route)892{893	struct cfg_reset_pkg request = { .header = tb_cfg_make_header(route) };894	struct tb_cfg_result res = { 0 };895	struct tb_cfg_header reply;896	struct tb_cfg_request *req;897 898	req = tb_cfg_request_alloc();899	if (!req) {900		res.err = -ENOMEM;901		return res;902	}903 904	req->match = tb_cfg_match;905	req->copy = tb_cfg_copy;906	req->request = &request;907	req->request_size = sizeof(request);908	req->request_type = TB_CFG_PKG_RESET;909	req->response = &reply;910	req->response_size = sizeof(reply);911	req->response_type = TB_CFG_PKG_RESET;912 913	res = tb_cfg_request_sync(ctl, req, ctl->timeout_msec);914 915	tb_cfg_request_put(req);916 917	return res;918}919 920/**921 * tb_cfg_read_raw() - read from config space into buffer922 * @ctl: Pointer to the control channel923 * @buffer: Buffer where the data is read924 * @route: Route string of the router925 * @port: Port number when reading from %TB_CFG_PORT, %0 otherwise926 * @space: Config space selector927 * @offset: Dword word offset of the register to start reading928 * @length: Number of dwords to read929 * @timeout_msec: Timeout in ms how long to wait for the response930 *931 * Reads from router config space without translating the possible error.932 */933struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,934		u64 route, u32 port, enum tb_cfg_space space,935		u32 offset, u32 length, int timeout_msec)936{937	struct tb_cfg_result res = { 0 };938	struct cfg_read_pkg request = {939		.header = tb_cfg_make_header(route),940		.addr = {941			.port = port,942			.space = space,943			.offset = offset,944			.length = length,945		},946	};947	struct cfg_write_pkg reply;948	int retries = 0;949 950	while (retries < TB_CTL_RETRIES) {951		struct tb_cfg_request *req;952 953		req = tb_cfg_request_alloc();954		if (!req) {955			res.err = -ENOMEM;956			return res;957		}958 959		request.addr.seq = retries++;960 961		req->match = tb_cfg_match;962		req->copy = tb_cfg_copy;963		req->request = &request;964		req->request_size = sizeof(request);965		req->request_type = TB_CFG_PKG_READ;966		req->response = &reply;967		req->response_size = 12 + 4 * length;968		req->response_type = TB_CFG_PKG_READ;969 970		res = tb_cfg_request_sync(ctl, req, timeout_msec);971 972		tb_cfg_request_put(req);973 974		if (res.err != -ETIMEDOUT)975			break;976 977		/* Wait a bit (arbitrary time) until we send a retry */978		usleep_range(10, 100);979	}980 981	if (res.err)982		return res;983 984	res.response_port = reply.addr.port;985	res.err = check_config_address(reply.addr, space, offset, length);986	if (!res.err)987		memcpy(buffer, &reply.data, 4 * length);988	return res;989}990 991/**992 * tb_cfg_write_raw() - write from buffer into config space993 * @ctl: Pointer to the control channel994 * @buffer: Data to write995 * @route: Route string of the router996 * @port: Port number when writing to %TB_CFG_PORT, %0 otherwise997 * @space: Config space selector998 * @offset: Dword word offset of the register to start writing999 * @length: Number of dwords to write1000 * @timeout_msec: Timeout in ms how long to wait for the response1001 *1002 * Writes to router config space without translating the possible error.1003 */1004struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer,1005		u64 route, u32 port, enum tb_cfg_space space,1006		u32 offset, u32 length, int timeout_msec)1007{1008	struct tb_cfg_result res = { 0 };1009	struct cfg_write_pkg request = {1010		.header = tb_cfg_make_header(route),1011		.addr = {1012			.port = port,1013			.space = space,1014			.offset = offset,1015			.length = length,1016		},1017	};1018	struct cfg_read_pkg reply;1019	int retries = 0;1020 1021	memcpy(&request.data, buffer, length * 4);1022 1023	while (retries < TB_CTL_RETRIES) {1024		struct tb_cfg_request *req;1025 1026		req = tb_cfg_request_alloc();1027		if (!req) {1028			res.err = -ENOMEM;1029			return res;1030		}1031 1032		request.addr.seq = retries++;1033 1034		req->match = tb_cfg_match;1035		req->copy = tb_cfg_copy;1036		req->request = &request;1037		req->request_size = 12 + 4 * length;1038		req->request_type = TB_CFG_PKG_WRITE;1039		req->response = &reply;1040		req->response_size = sizeof(reply);1041		req->response_type = TB_CFG_PKG_WRITE;1042 1043		res = tb_cfg_request_sync(ctl, req, timeout_msec);1044 1045		tb_cfg_request_put(req);1046 1047		if (res.err != -ETIMEDOUT)1048			break;1049 1050		/* Wait a bit (arbitrary time) until we send a retry */1051		usleep_range(10, 100);1052	}1053 1054	if (res.err)1055		return res;1056 1057	res.response_port = reply.addr.port;1058	res.err = check_config_address(reply.addr, space, offset, length);1059	return res;1060}1061 1062static int tb_cfg_get_error(struct tb_ctl *ctl, enum tb_cfg_space space,1063			    const struct tb_cfg_result *res)1064{1065	/*1066	 * For unimplemented ports access to port config space may return1067	 * TB_CFG_ERROR_INVALID_CONFIG_SPACE (alternatively their type is1068	 * set to TB_TYPE_INACTIVE). In the former case return -ENODEV so1069	 * that the caller can mark the port as disabled.1070	 */1071	if (space == TB_CFG_PORT &&1072	    res->tb_error == TB_CFG_ERROR_INVALID_CONFIG_SPACE)1073		return -ENODEV;1074 1075	tb_cfg_print_error(ctl, res);1076 1077	if (res->tb_error == TB_CFG_ERROR_LOCK)1078		return -EACCES;1079	if (res->tb_error == TB_CFG_ERROR_PORT_NOT_CONNECTED)1080		return -ENOTCONN;1081 1082	return -EIO;1083}1084 1085int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,1086		enum tb_cfg_space space, u32 offset, u32 length)1087{1088	struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,1089			space, offset, length, ctl->timeout_msec);1090	switch (res.err) {1091	case 0:1092		/* Success */1093		break;1094 1095	case 1:1096		/* Thunderbolt error, tb_error holds the actual number */1097		return tb_cfg_get_error(ctl, space, &res);1098 1099	case -ETIMEDOUT:1100		tb_ctl_warn(ctl, "%llx: timeout reading config space %u from %#x\n",1101			    route, space, offset);1102		break;1103 1104	default:1105		WARN(1, "tb_cfg_read: %d\n", res.err);1106		break;1107	}1108	return res.err;1109}1110 1111int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port,1112		 enum tb_cfg_space space, u32 offset, u32 length)1113{1114	struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,1115			space, offset, length, ctl->timeout_msec);1116	switch (res.err) {1117	case 0:1118		/* Success */1119		break;1120 1121	case 1:1122		/* Thunderbolt error, tb_error holds the actual number */1123		return tb_cfg_get_error(ctl, space, &res);1124 1125	case -ETIMEDOUT:1126		tb_ctl_warn(ctl, "%llx: timeout writing config space %u to %#x\n",1127			    route, space, offset);1128		break;1129 1130	default:1131		WARN(1, "tb_cfg_write: %d\n", res.err);1132		break;1133	}1134	return res.err;1135}1136 1137/**1138 * tb_cfg_get_upstream_port() - get upstream port number of switch at route1139 * @ctl: Pointer to the control channel1140 * @route: Route string of the router1141 *1142 * Reads the first dword from the switches TB_CFG_SWITCH config area and1143 * returns the port number from which the reply originated.1144 *1145 * Return: Returns the upstream port number on success or an error code on1146 * failure.1147 */1148int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)1149{1150	u32 dummy;1151	struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,1152						   TB_CFG_SWITCH, 0, 1,1153						   ctl->timeout_msec);1154	if (res.err == 1)1155		return -EIO;1156	if (res.err)1157		return res.err;1158	return res.response_port;1159}1160