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// SPDX-License-Identifier: GPL-2.0/* * Thunderbolt driver - control channel and configuration commands * * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> * Copyright (C) 2018, Intel Corporation */ #include <linux/crc32.h>#include <linux/delay.h>#include <linux/slab.h>#include <linux/pci.h>#include <linux/dmapool.h>#include <linux/workqueue.h> #include "ctl.h" #define CREATE_TRACE_POINTS#include "trace.h" #define TB_CTL_RX_PKG_COUNT	10#define TB_CTL_RETRIES		4 /** * struct tb_ctl - Thunderbolt control channel * @nhi: Pointer to the NHI structure * @tx: Transmit ring * @rx: Receive ring * @frame_pool: DMA pool for control messages * @rx_packets: Received control messages * @request_queue_lock: Lock protecting @request_queue * @request_queue: List of outstanding requests * @running: Is the control channel running at the moment * @timeout_msec: Default timeout for non-raw control messages * @callback: Callback called when hotplug message is received * @callback_data: Data passed to @callback * @index: Domain number. This will be output with the trace record. */struct tb_ctl {	struct tb_nhi *nhi;	struct tb_ring *tx;	struct tb_ring *rx; 	struct dma_pool *frame_pool;	struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT];	struct mutex request_queue_lock;	struct list_head request_queue;	bool running; 	int timeout_msec;	event_cb callback;	void *callback_data; 	int index;};  #define tb_ctl_WARN(ctl, format, arg...) \	dev_WARN((ctl)->nhi->dev, format, ## arg) #define tb_ctl_err(ctl, format, arg...) \	dev_err((ctl)->nhi->dev, format, ## arg) #define tb_ctl_warn(ctl, format, arg...) \	dev_warn((ctl)->nhi->dev, format, ## arg) #define tb_ctl_info(ctl, format, arg...) \	dev_info((ctl)->nhi->dev, format, ## arg) #define tb_ctl_dbg(ctl, format, arg...) \	dev_dbg((ctl)->nhi->dev, format, ## arg) #define tb_ctl_dbg_once(ctl, format, arg...) \	dev_dbg_once((ctl)->nhi->dev, format, ## arg) static DECLARE_WAIT_QUEUE_HEAD(tb_cfg_request_cancel_queue);/* Serializes access to request kref_get/put */static DEFINE_MUTEX(tb_cfg_request_lock); /** * tb_cfg_request_alloc() - Allocates a new config request * * This is refcounted object so when you are done with this, call * tb_cfg_request_put() to it. * * Return: &struct tb_cfg_request on success, %NULL otherwise. */struct tb_cfg_request *tb_cfg_request_alloc(void){	struct tb_cfg_request *req; 	req = kzalloc_obj(*req);	if (!req)		return NULL; 	kref_init(&req->kref); 	return req;} /** * tb_cfg_request_get() - Increase refcount of a request * @req: Request whose refcount is increased */void tb_cfg_request_get(struct tb_cfg_request *req){	mutex_lock(&tb_cfg_request_lock);	kref_get(&req->kref);	mutex_unlock(&tb_cfg_request_lock);} static void tb_cfg_request_destroy(struct kref *kref){	struct tb_cfg_request *req = container_of(kref, typeof(*req), kref); 	kfree(req);} /** * tb_cfg_request_put() - Decrease refcount and possibly release the request * @req: Request whose refcount is decreased * * Call this function when you are done with the request. When refcount * goes to %0 the object is released. */void tb_cfg_request_put(struct tb_cfg_request *req){	mutex_lock(&tb_cfg_request_lock);	kref_put(&req->kref, tb_cfg_request_destroy);	mutex_unlock(&tb_cfg_request_lock);} static int tb_cfg_request_enqueue(struct tb_ctl *ctl,				  struct tb_cfg_request *req){	WARN_ON(test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags));	WARN_ON(req->ctl); 	mutex_lock(&ctl->request_queue_lock);	if (!ctl->running) {		mutex_unlock(&ctl->request_queue_lock);		return -ENOTCONN;	}	req->ctl = ctl;	list_add_tail(&req->list, &ctl->request_queue);	set_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);	mutex_unlock(&ctl->request_queue_lock);	return 0;} static void tb_cfg_request_dequeue(struct tb_cfg_request *req){	struct tb_ctl *ctl = req->ctl; 	mutex_lock(&ctl->request_queue_lock);	if (!test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags)) {		mutex_unlock(&ctl->request_queue_lock);		return;	} 	list_del(&req->list);	clear_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);	if (test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))		wake_up(&tb_cfg_request_cancel_queue);	mutex_unlock(&ctl->request_queue_lock);} static bool tb_cfg_request_is_active(struct tb_cfg_request *req){	return test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);} static struct tb_cfg_request *tb_cfg_request_find(struct tb_ctl *ctl, struct ctl_pkg *pkg){	struct tb_cfg_request *req = NULL, *iter; 	mutex_lock(&pkg->ctl->request_queue_lock);	list_for_each_entry(iter, &pkg->ctl->request_queue, list) {		tb_cfg_request_get(iter);		if (iter->match(iter, pkg)) {			req = iter;			break;		}		tb_cfg_request_put(iter);	}	mutex_unlock(&pkg->ctl->request_queue_lock); 	return req;} /* utility functions */  static int check_header(const struct ctl_pkg *pkg, u32 len,			enum tb_cfg_pkg_type type, u64 route){	struct tb_cfg_header *header = pkg->buffer; 	/* check frame, TODO: frame flags */	if (WARN(len != pkg->frame.size,			"wrong framesize (expected %#x, got %#x)\n",			len, pkg->frame.size))		return -EIO;	if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n",			type, pkg->frame.eof))		return -EIO;	if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n",			pkg->frame.sof))		return -EIO; 	/* check header */	if (WARN(header->unknown != 1 << 9,			"header->unknown is %#x\n", header->unknown))		return -EIO;	if (WARN(route != tb_cfg_get_route(header),			"wrong route (expected %llx, got %llx)",			route, tb_cfg_get_route(header)))		return -EIO;	return 0;} static int check_config_address(struct tb_cfg_address addr,				enum tb_cfg_space space, u32 offset,				u32 length){	if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero))		return -EIO;	if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)",			space, addr.space))		return -EIO;	if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)",			offset, addr.offset))		return -EIO;	if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)",			length, addr.length))		return -EIO;	/*	 * We cannot check addr->port as it is set to the upstream port of the	 * sender.	 */	return 0;} static struct tb_cfg_result decode_error(const struct ctl_pkg *response){	struct cfg_error_pkg *pkg = response->buffer;	struct tb_cfg_result res = { 0 };	res.response_route = tb_cfg_get_route(&pkg->header);	res.response_port = 0;	res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR,			       tb_cfg_get_route(&pkg->header));	if (res.err)		return res; 	res.err = 1;	res.tb_error = pkg->error;	res.response_port = pkg->port;	return res; } static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len,					 enum tb_cfg_pkg_type type, u64 route){	struct tb_cfg_header *header = pkg->buffer;	struct tb_cfg_result res = { 0 }; 	if (pkg->frame.eof == TB_CFG_PKG_ERROR)		return decode_error(pkg); 	res.response_port = 0; /* will be updated later for cfg_read/write */	res.response_route = tb_cfg_get_route(header);	res.err = check_header(pkg, len, type, route);	return res;} static void tb_cfg_print_error(struct tb_ctl *ctl, enum tb_cfg_space space,			       const struct tb_cfg_result *res){	WARN_ON(res->err != 1);	switch (res->tb_error) {	case TB_CFG_ERROR_PORT_NOT_CONNECTED:		/* Port is not connected. This can happen during surprise		 * removal. Do not warn. */		return;	case TB_CFG_ERROR_INVALID_CONFIG_SPACE:		/*		 * Invalid cfg_space/offset/length combination in		 * cfg_read/cfg_write.		 */		tb_ctl_dbg_once(ctl, "%llx:%x: invalid config space (%u) or offset\n",				res->response_route, res->response_port, space);		return;	case TB_CFG_ERROR_NO_SUCH_PORT:		/*		 * - The route contains a non-existent port.		 * - The route contains a non-PHY port (e.g. PCIe).		 * - The port in cfg_read/cfg_write does not exist.		 */		tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",			res->response_route, res->response_port);		return;	case TB_CFG_ERROR_LOOP:		tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",			res->response_route, res->response_port);		return;	case TB_CFG_ERROR_LOCK:		tb_ctl_warn(ctl, "%llx:%x: downstream port is locked\n",			    res->response_route, res->response_port);		return;	default:		/* 5,6,7,9 and 11 are also valid error codes */		tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",			res->response_route, res->response_port);		return;	}} static __be32 tb_crc(const void *data, size_t len){	return cpu_to_be32(~crc32c(~0, data, len));} static void tb_ctl_pkg_free(struct ctl_pkg *pkg){	if (pkg) {		dma_pool_free(pkg->ctl->frame_pool,			      pkg->buffer, pkg->frame.buffer_phy);		kfree(pkg);	}} static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl){	struct ctl_pkg *pkg = kzalloc_obj(*pkg);	if (!pkg)		return NULL;	pkg->ctl = ctl;	pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL,				     &pkg->frame.buffer_phy);	if (!pkg->buffer) {		kfree(pkg);		return NULL;	}	return pkg;}  /* RX/TX handling */ static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,			       bool canceled){	struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);	tb_ctl_pkg_free(pkg);} /* * tb_cfg_tx() - transmit a packet on the control channel * * len must be a multiple of four. * * Return: %0 on success, negative errno otherwise. */static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len,		     enum tb_cfg_pkg_type type){	int res;	struct ctl_pkg *pkg;	if (len % 4 != 0) { /* required for le->be conversion */		tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);		return -EINVAL;	}	if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */		tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",			    len, TB_FRAME_SIZE - 4);		return -EINVAL;	}	pkg = tb_ctl_pkg_alloc(ctl);	if (!pkg)		return -ENOMEM;	pkg->frame.callback = tb_ctl_tx_callback;	pkg->frame.size = len + 4;	pkg->frame.sof = type;	pkg->frame.eof = type; 	trace_tb_tx(ctl->index, type, data, len); 	cpu_to_be32_array(pkg->buffer, data, len / 4);	*(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len); 	res = tb_ring_tx(ctl->tx, &pkg->frame);	if (res) /* ring is stopped */		tb_ctl_pkg_free(pkg);	return res;} /* * tb_ctl_handle_event() - acknowledge a plug event, invoke ctl->callback */static bool tb_ctl_handle_event(struct tb_ctl *ctl, enum tb_cfg_pkg_type type,				struct ctl_pkg *pkg, size_t size){	trace_tb_event(ctl->index, type, pkg->buffer, size);	return ctl->callback(ctl->callback_data, type, pkg->buffer, size);} static void tb_ctl_rx_submit(struct ctl_pkg *pkg){	tb_ring_rx(pkg->ctl->rx, &pkg->frame); /*					     * We ignore failures during stop.					     * All rx packets are referenced					     * from ctl->rx_packets, so we do					     * not lose them.					     */} static int tb_async_error(const struct ctl_pkg *pkg){	const struct cfg_error_pkg *error = pkg->buffer; 	if (pkg->frame.eof != TB_CFG_PKG_ERROR)		return false; 	switch (error->error) {	case TB_CFG_ERROR_LINK_ERROR:	case TB_CFG_ERROR_HEC_ERROR_DETECTED:	case TB_CFG_ERROR_FLOW_CONTROL_ERROR:	case TB_CFG_ERROR_DP_BW:	case TB_CFG_ERROR_ROP_CMPLT:	case TB_CFG_ERROR_POP_CMPLT:	case TB_CFG_ERROR_PCIE_WAKE:	case TB_CFG_ERROR_DP_CON_CHANGE:	case TB_CFG_ERROR_DPTX_DISCOVERY:	case TB_CFG_ERROR_LINK_RECOVERY:	case TB_CFG_ERROR_ASYM_LINK:		return true; 	default:		return false;	}} static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,			       bool canceled){	struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);	struct tb_cfg_request *req;	__be32 crc32; 	if (canceled)		return; /*			 * ring is stopped, packet is referenced from			 * ctl->rx_packets.			 */ 	if (frame->size < 4 || frame->size % 4 != 0) {		tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",			   frame->size);		goto rx;	} 	frame->size -= 4; /* remove checksum */	crc32 = tb_crc(pkg->buffer, frame->size);	be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4); 	switch (frame->eof) {	case TB_CFG_PKG_READ:	case TB_CFG_PKG_WRITE:	case TB_CFG_PKG_ERROR:	case TB_CFG_PKG_OVERRIDE:	case TB_CFG_PKG_RESET:		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {			tb_ctl_err(pkg->ctl,				   "RX: checksum mismatch, dropping packet\n");			goto rx;		}		if (tb_async_error(pkg)) {			tb_ctl_handle_event(pkg->ctl, frame->eof,					    pkg, frame->size);			goto rx;		}		break; 	case TB_CFG_PKG_EVENT:	case TB_CFG_PKG_XDOMAIN_RESP:	case TB_CFG_PKG_XDOMAIN_REQ:		if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {			tb_ctl_err(pkg->ctl,				   "RX: checksum mismatch, dropping packet\n");			goto rx;		}		fallthrough;	case TB_CFG_PKG_ICM_EVENT:		if (tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size))			goto rx;		break; 	default:

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