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-rw-r--r--drivers/thunderbolt/ctl.c1144
1 files changed, 1144 insertions, 0 deletions
diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c
new file mode 100644
index 0000000000..d997a4c545
--- /dev/null
+++ b/drivers/thunderbolt/ctl.c
@@ -0,0 +1,1144 @@
+// 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 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
+ */
+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;
+};
+
+
+#define tb_ctl_WARN(ctl, format, arg...) \
+ dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_err(ctl, format, arg...) \
+ dev_err(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_warn(ctl, format, arg...) \
+ dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_info(ctl, format, arg...) \
+ dev_info(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_dbg(ctl, format, arg...) \
+ dev_dbg(&(ctl)->nhi->pdev->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.
+ */
+struct tb_cfg_request *tb_cfg_request_alloc(void)
+{
+ struct tb_cfg_request *req;
+
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
+ 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);
+ 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,
+ 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(ctl, "%llx:%x: invalid config space or offset\n",
+ res->response_route, res->response_port);
+ 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_le(~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(sizeof(*pkg), GFP_KERNEL);
+ 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: Returns 0 on success or an error code on failure.
+ */
+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;
+ 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)
+{
+ 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 loose 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:
+ break;
+ }
+
+ /*
+ * The received packet will be processed only if there is an
+ * active request and that the packet is what is expected. This
+ * prevents packets such as replies coming after timeout has
+ * triggered from messing with the active requests.
+ */
+ req = tb_cfg_request_find(pkg->ctl, pkg);
+ if (req) {
+ if (req->copy(req, pkg))
+ schedule_work(&req->work);
+ tb_cfg_request_put(req);
+ }
+
+rx:
+ tb_ctl_rx_submit(pkg);
+}
+
+static void tb_cfg_request_work(struct work_struct *work)
+{
+ struct tb_cfg_request *req = container_of(work, typeof(*req), work);
+
+ if (!test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))
+ req->callback(req->callback_data);
+
+ tb_cfg_request_dequeue(req);
+ tb_cfg_request_put(req);
+}
+
+/**
+ * tb_cfg_request() - Start control request not waiting for it to complete
+ * @ctl: Control channel to use
+ * @req: Request to start
+ * @callback: Callback called when the request is completed
+ * @callback_data: Data to be passed to @callback
+ *
+ * This queues @req on the given control channel without waiting for it
+ * to complete. When the request completes @callback is called.
+ */
+int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req,
+ void (*callback)(void *), void *callback_data)
+{
+ int ret;
+
+ req->flags = 0;
+ req->callback = callback;
+ req->callback_data = callback_data;
+ INIT_WORK(&req->work, tb_cfg_request_work);
+ INIT_LIST_HEAD(&req->list);
+
+ tb_cfg_request_get(req);
+ ret = tb_cfg_request_enqueue(ctl, req);
+ if (ret)
+ goto err_put;
+
+ ret = tb_ctl_tx(ctl, req->request, req->request_size,
+ req->request_type);
+ if (ret)
+ goto err_dequeue;
+
+ if (!req->response)
+ schedule_work(&req->work);
+
+ return 0;
+
+err_dequeue:
+ tb_cfg_request_dequeue(req);
+err_put:
+ tb_cfg_request_put(req);
+
+ return ret;
+}
+
+/**
+ * tb_cfg_request_cancel() - Cancel a control request
+ * @req: Request to cancel
+ * @err: Error to assign to the request
+ *
+ * This function can be used to cancel ongoing request. It will wait
+ * until the request is not active anymore.
+ */
+void tb_cfg_request_cancel(struct tb_cfg_request *req, int err)
+{
+ set_bit(TB_CFG_REQUEST_CANCELED, &req->flags);
+ schedule_work(&req->work);
+ wait_event(tb_cfg_request_cancel_queue, !tb_cfg_request_is_active(req));
+ req->result.err = err;
+}
+
+static void tb_cfg_request_complete(void *data)
+{
+ complete(data);
+}
+
+/**
+ * tb_cfg_request_sync() - Start control request and wait until it completes
+ * @ctl: Control channel to use
+ * @req: Request to start
+ * @timeout_msec: Timeout how long to wait @req to complete
+ *
+ * Starts a control request and waits until it completes. If timeout
+ * triggers the request is canceled before function returns. Note the
+ * caller needs to make sure only one message for given switch is active
+ * at a time.
+ */
+struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl,
+ struct tb_cfg_request *req,
+ int timeout_msec)
+{
+ unsigned long timeout = msecs_to_jiffies(timeout_msec);
+ struct tb_cfg_result res = { 0 };
+ DECLARE_COMPLETION_ONSTACK(done);
+ int ret;
+
+ ret = tb_cfg_request(ctl, req, tb_cfg_request_complete, &done);
+ if (ret) {
+ res.err = ret;
+ return res;
+ }
+
+ if (!wait_for_completion_timeout(&done, timeout))
+ tb_cfg_request_cancel(req, -ETIMEDOUT);
+
+ flush_work(&req->work);
+
+ return req->result;
+}
+
+/* public interface, alloc/start/stop/free */
+
+/**
+ * tb_ctl_alloc() - allocate a control channel
+ * @nhi: Pointer to NHI
+ * @timeout_msec: Default timeout used with non-raw control messages
+ * @cb: Callback called for plug events
+ * @cb_data: Data passed to @cb
+ *
+ * cb will be invoked once for every hot plug event.
+ *
+ * Return: Returns a pointer on success or NULL on failure.
+ */
+struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int timeout_msec, event_cb cb,
+ void *cb_data)
+{
+ int i;
+ struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
+ if (!ctl)
+ return NULL;
+ ctl->nhi = nhi;
+ ctl->timeout_msec = timeout_msec;
+ ctl->callback = cb;
+ ctl->callback_data = cb_data;
+
+ mutex_init(&ctl->request_queue_lock);
+ INIT_LIST_HEAD(&ctl->request_queue);
+ ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev,
+ TB_FRAME_SIZE, 4, 0);
+ if (!ctl->frame_pool)
+ goto err;
+
+ ctl->tx = tb_ring_alloc_tx(nhi, 0, 10, RING_FLAG_NO_SUSPEND);
+ if (!ctl->tx)
+ goto err;
+
+ ctl->rx = tb_ring_alloc_rx(nhi, 0, 10, RING_FLAG_NO_SUSPEND, 0, 0xffff,
+ 0xffff, NULL, NULL);
+ if (!ctl->rx)
+ goto err;
+
+ for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) {
+ ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl);
+ if (!ctl->rx_packets[i])
+ goto err;
+ ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback;
+ }
+
+ tb_ctl_dbg(ctl, "control channel created\n");
+ return ctl;
+err:
+ tb_ctl_free(ctl);
+ return NULL;
+}
+
+/**
+ * tb_ctl_free() - free a control channel
+ * @ctl: Control channel to free
+ *
+ * Must be called after tb_ctl_stop.
+ *
+ * Must NOT be called from ctl->callback.
+ */
+void tb_ctl_free(struct tb_ctl *ctl)
+{
+ int i;
+
+ if (!ctl)
+ return;
+
+ if (ctl->rx)
+ tb_ring_free(ctl->rx);
+ if (ctl->tx)
+ tb_ring_free(ctl->tx);
+
+ /* free RX packets */
+ for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
+ tb_ctl_pkg_free(ctl->rx_packets[i]);
+
+
+ dma_pool_destroy(ctl->frame_pool);
+ kfree(ctl);
+}
+
+/**
+ * tb_ctl_start() - start/resume the control channel
+ * @ctl: Control channel to start
+ */
+void tb_ctl_start(struct tb_ctl *ctl)
+{
+ int i;
+ tb_ctl_dbg(ctl, "control channel starting...\n");
+ tb_ring_start(ctl->tx); /* is used to ack hotplug packets, start first */
+ tb_ring_start(ctl->rx);
+ for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
+ tb_ctl_rx_submit(ctl->rx_packets[i]);
+
+ ctl->running = true;
+}
+
+/**
+ * tb_ctl_stop() - pause the control channel
+ * @ctl: Control channel to stop
+ *
+ * All invocations of ctl->callback will have finished after this method
+ * returns.
+ *
+ * Must NOT be called from ctl->callback.
+ */
+void tb_ctl_stop(struct tb_ctl *ctl)
+{
+ mutex_lock(&ctl->request_queue_lock);
+ ctl->running = false;
+ mutex_unlock(&ctl->request_queue_lock);
+
+ tb_ring_stop(ctl->rx);
+ tb_ring_stop(ctl->tx);
+
+ if (!list_empty(&ctl->request_queue))
+ tb_ctl_WARN(ctl, "dangling request in request_queue\n");
+ INIT_LIST_HEAD(&ctl->request_queue);
+ tb_ctl_dbg(ctl, "control channel stopped\n");
+}
+
+/* public interface, commands */
+
+/**
+ * tb_cfg_ack_notification() - Ack notification
+ * @ctl: Control channel to use
+ * @route: Router that originated the event
+ * @error: Pointer to the notification package
+ *
+ * Call this as response for non-plug notification to ack it. Returns
+ * %0 on success or an error code on failure.
+ */
+int tb_cfg_ack_notification(struct tb_ctl *ctl, u64 route,
+ const struct cfg_error_pkg *error)
+{
+ struct cfg_ack_pkg pkg = {
+ .header = tb_cfg_make_header(route),
+ };
+ const char *name;
+
+ switch (error->error) {
+ case TB_CFG_ERROR_LINK_ERROR:
+ name = "link error";
+ break;
+ case TB_CFG_ERROR_HEC_ERROR_DETECTED:
+ name = "HEC error";
+ break;
+ case TB_CFG_ERROR_FLOW_CONTROL_ERROR:
+ name = "flow control error";
+ break;
+ case TB_CFG_ERROR_DP_BW:
+ name = "DP_BW";
+ break;
+ case TB_CFG_ERROR_ROP_CMPLT:
+ name = "router operation completion";
+ break;
+ case TB_CFG_ERROR_POP_CMPLT:
+ name = "port operation completion";
+ break;
+ case TB_CFG_ERROR_PCIE_WAKE:
+ name = "PCIe wake";
+ break;
+ case TB_CFG_ERROR_DP_CON_CHANGE:
+ name = "DP connector change";
+ break;
+ case TB_CFG_ERROR_DPTX_DISCOVERY:
+ name = "DPTX discovery";
+ break;
+ case TB_CFG_ERROR_LINK_RECOVERY:
+ name = "link recovery";
+ break;
+ case TB_CFG_ERROR_ASYM_LINK:
+ name = "asymmetric link";
+ break;
+ default:
+ name = "unknown";
+ break;
+ }
+
+ tb_ctl_dbg(ctl, "acking %s (%#x) notification on %llx\n", name,
+ error->error, route);
+
+ return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_NOTIFY_ACK);
+}
+
+/**
+ * tb_cfg_ack_plug() - Ack hot plug/unplug event
+ * @ctl: Control channel to use
+ * @route: Router that originated the event
+ * @port: Port where the hot plug/unplug happened
+ * @unplug: Ack hot plug or unplug
+ *
+ * Call this as response for hot plug/unplug event to ack it.
+ * Returns %0 on success or an error code on failure.
+ */
+int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug)
+{
+ struct cfg_error_pkg pkg = {
+ .header = tb_cfg_make_header(route),
+ .port = port,
+ .error = TB_CFG_ERROR_ACK_PLUG_EVENT,
+ .pg = unplug ? TB_CFG_ERROR_PG_HOT_UNPLUG
+ : TB_CFG_ERROR_PG_HOT_PLUG,
+ };
+ tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%u\n",
+ unplug ? "un" : "", route, port);
+ return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
+}
+
+static bool tb_cfg_match(const struct tb_cfg_request *req,
+ const struct ctl_pkg *pkg)
+{
+ u64 route = tb_cfg_get_route(pkg->buffer) & ~BIT_ULL(63);
+
+ if (pkg->frame.eof == TB_CFG_PKG_ERROR)
+ return true;
+
+ if (pkg->frame.eof != req->response_type)
+ return false;
+ if (route != tb_cfg_get_route(req->request))
+ return false;
+ if (pkg->frame.size != req->response_size)
+ return false;
+
+ if (pkg->frame.eof == TB_CFG_PKG_READ ||
+ pkg->frame.eof == TB_CFG_PKG_WRITE) {
+ const struct cfg_read_pkg *req_hdr = req->request;
+ const struct cfg_read_pkg *res_hdr = pkg->buffer;
+
+ if (req_hdr->addr.seq != res_hdr->addr.seq)
+ return false;
+ }
+
+ return true;
+}
+
+static bool tb_cfg_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg)
+{
+ struct tb_cfg_result res;
+
+ /* Now make sure it is in expected format */
+ res = parse_header(pkg, req->response_size, req->response_type,
+ tb_cfg_get_route(req->request));
+ if (!res.err)
+ memcpy(req->response, pkg->buffer, req->response_size);
+
+ req->result = res;
+
+ /* Always complete when first response is received */
+ return true;
+}
+
+/**
+ * tb_cfg_reset() - send a reset packet and wait for a response
+ * @ctl: Control channel pointer
+ * @route: Router string for the router to send reset
+ *
+ * If the switch at route is incorrectly configured then we will not receive a
+ * reply (even though the switch will reset). The caller should check for
+ * -ETIMEDOUT and attempt to reconfigure the switch.
+ */
+struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route)
+{
+ struct cfg_reset_pkg request = { .header = tb_cfg_make_header(route) };
+ struct tb_cfg_result res = { 0 };
+ struct tb_cfg_header reply;
+ struct tb_cfg_request *req;
+
+ req = tb_cfg_request_alloc();
+ if (!req) {
+ res.err = -ENOMEM;
+ return res;
+ }
+
+ req->match = tb_cfg_match;
+ req->copy = tb_cfg_copy;
+ req->request = &request;
+ req->request_size = sizeof(request);
+ req->request_type = TB_CFG_PKG_RESET;
+ req->response = &reply;
+ req->response_size = sizeof(reply);
+ req->response_type = TB_CFG_PKG_RESET;
+
+ res = tb_cfg_request_sync(ctl, req, ctl->timeout_msec);
+
+ tb_cfg_request_put(req);
+
+ return res;
+}
+
+/**
+ * tb_cfg_read_raw() - read from config space into buffer
+ * @ctl: Pointer to the control channel
+ * @buffer: Buffer where the data is read
+ * @route: Route string of the router
+ * @port: Port number when reading from %TB_CFG_PORT, %0 otherwise
+ * @space: Config space selector
+ * @offset: Dword word offset of the register to start reading
+ * @length: Number of dwords to read
+ * @timeout_msec: Timeout in ms how long to wait for the response
+ *
+ * Reads from router config space without translating the possible error.
+ */
+struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
+ u64 route, u32 port, enum tb_cfg_space space,
+ u32 offset, u32 length, int timeout_msec)
+{
+ struct tb_cfg_result res = { 0 };
+ struct cfg_read_pkg request = {
+ .header = tb_cfg_make_header(route),
+ .addr = {
+ .port = port,
+ .space = space,
+ .offset = offset,
+ .length = length,
+ },
+ };
+ struct cfg_write_pkg reply;
+ int retries = 0;
+
+ while (retries < TB_CTL_RETRIES) {
+ struct tb_cfg_request *req;
+
+ req = tb_cfg_request_alloc();
+ if (!req) {
+ res.err = -ENOMEM;
+ return res;
+ }
+
+ request.addr.seq = retries++;
+
+ req->match = tb_cfg_match;
+ req->copy = tb_cfg_copy;
+ req->request = &request;
+ req->request_size = sizeof(request);
+ req->request_type = TB_CFG_PKG_READ;
+ req->response = &reply;
+ req->response_size = 12 + 4 * length;
+ req->response_type = TB_CFG_PKG_READ;
+
+ res = tb_cfg_request_sync(ctl, req, timeout_msec);
+
+ tb_cfg_request_put(req);
+
+ if (res.err != -ETIMEDOUT)
+ break;
+
+ /* Wait a bit (arbitrary time) until we send a retry */
+ usleep_range(10, 100);
+ }
+
+ if (res.err)
+ return res;
+
+ res.response_port = reply.addr.port;
+ res.err = check_config_address(reply.addr, space, offset, length);
+ if (!res.err)
+ memcpy(buffer, &reply.data, 4 * length);
+ return res;
+}
+
+/**
+ * tb_cfg_write_raw() - write from buffer into config space
+ * @ctl: Pointer to the control channel
+ * @buffer: Data to write
+ * @route: Route string of the router
+ * @port: Port number when writing to %TB_CFG_PORT, %0 otherwise
+ * @space: Config space selector
+ * @offset: Dword word offset of the register to start writing
+ * @length: Number of dwords to write
+ * @timeout_msec: Timeout in ms how long to wait for the response
+ *
+ * Writes to router config space without translating the possible error.
+ */
+struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer,
+ u64 route, u32 port, enum tb_cfg_space space,
+ u32 offset, u32 length, int timeout_msec)
+{
+ struct tb_cfg_result res = { 0 };
+ struct cfg_write_pkg request = {
+ .header = tb_cfg_make_header(route),
+ .addr = {
+ .port = port,
+ .space = space,
+ .offset = offset,
+ .length = length,
+ },
+ };
+ struct cfg_read_pkg reply;
+ int retries = 0;
+
+ memcpy(&request.data, buffer, length * 4);
+
+ while (retries < TB_CTL_RETRIES) {
+ struct tb_cfg_request *req;
+
+ req = tb_cfg_request_alloc();
+ if (!req) {
+ res.err = -ENOMEM;
+ return res;
+ }
+
+ request.addr.seq = retries++;
+
+ req->match = tb_cfg_match;
+ req->copy = tb_cfg_copy;
+ req->request = &request;
+ req->request_size = 12 + 4 * length;
+ req->request_type = TB_CFG_PKG_WRITE;
+ req->response = &reply;
+ req->response_size = sizeof(reply);
+ req->response_type = TB_CFG_PKG_WRITE;
+
+ res = tb_cfg_request_sync(ctl, req, timeout_msec);
+
+ tb_cfg_request_put(req);
+
+ if (res.err != -ETIMEDOUT)
+ break;
+
+ /* Wait a bit (arbitrary time) until we send a retry */
+ usleep_range(10, 100);
+ }
+
+ if (res.err)
+ return res;
+
+ res.response_port = reply.addr.port;
+ res.err = check_config_address(reply.addr, space, offset, length);
+ return res;
+}
+
+static int tb_cfg_get_error(struct tb_ctl *ctl, enum tb_cfg_space space,
+ const struct tb_cfg_result *res)
+{
+ /*
+ * For unimplemented ports access to port config space may return
+ * TB_CFG_ERROR_INVALID_CONFIG_SPACE (alternatively their type is
+ * set to TB_TYPE_INACTIVE). In the former case return -ENODEV so
+ * that the caller can mark the port as disabled.
+ */
+ if (space == TB_CFG_PORT &&
+ res->tb_error == TB_CFG_ERROR_INVALID_CONFIG_SPACE)
+ return -ENODEV;
+
+ tb_cfg_print_error(ctl, res);
+
+ if (res->tb_error == TB_CFG_ERROR_LOCK)
+ return -EACCES;
+ if (res->tb_error == TB_CFG_ERROR_PORT_NOT_CONNECTED)
+ return -ENOTCONN;
+
+ return -EIO;
+}
+
+int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
+ enum tb_cfg_space space, u32 offset, u32 length)
+{
+ struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
+ space, offset, length, ctl->timeout_msec);
+ switch (res.err) {
+ case 0:
+ /* Success */
+ break;
+
+ case 1:
+ /* Thunderbolt error, tb_error holds the actual number */
+ return tb_cfg_get_error(ctl, space, &res);
+
+ case -ETIMEDOUT:
+ tb_ctl_warn(ctl, "%llx: timeout reading config space %u from %#x\n",
+ route, space, offset);
+ break;
+
+ default:
+ WARN(1, "tb_cfg_read: %d\n", res.err);
+ break;
+ }
+ return res.err;
+}
+
+int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port,
+ enum tb_cfg_space space, u32 offset, u32 length)
+{
+ struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
+ space, offset, length, ctl->timeout_msec);
+ switch (res.err) {
+ case 0:
+ /* Success */
+ break;
+
+ case 1:
+ /* Thunderbolt error, tb_error holds the actual number */
+ return tb_cfg_get_error(ctl, space, &res);
+
+ case -ETIMEDOUT:
+ tb_ctl_warn(ctl, "%llx: timeout writing config space %u to %#x\n",
+ route, space, offset);
+ break;
+
+ default:
+ WARN(1, "tb_cfg_write: %d\n", res.err);
+ break;
+ }
+ return res.err;
+}
+
+/**
+ * tb_cfg_get_upstream_port() - get upstream port number of switch at route
+ * @ctl: Pointer to the control channel
+ * @route: Route string of the router
+ *
+ * Reads the first dword from the switches TB_CFG_SWITCH config area and
+ * returns the port number from which the reply originated.
+ *
+ * Return: Returns the upstream port number on success or an error code on
+ * failure.
+ */
+int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
+{
+ u32 dummy;
+ struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,
+ TB_CFG_SWITCH, 0, 1,
+ ctl->timeout_msec);
+ if (res.err == 1)
+ return -EIO;
+ if (res.err)
+ return res.err;
+ return res.response_port;
+}