From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/thunderbolt/path.c | 631 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 631 insertions(+) create mode 100644 drivers/thunderbolt/path.c (limited to 'drivers/thunderbolt/path.c') diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c new file mode 100644 index 000000000..b2c322e76 --- /dev/null +++ b/drivers/thunderbolt/path.c @@ -0,0 +1,631 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Thunderbolt driver - path/tunnel functionality + * + * Copyright (c) 2014 Andreas Noever + * Copyright (C) 2019, Intel Corporation + */ + +#include +#include +#include +#include + +#include "tb.h" + +static void tb_dump_hop(const struct tb_path_hop *hop, const struct tb_regs_hop *regs) +{ + const struct tb_port *port = hop->in_port; + + tb_port_dbg(port, " In HopID: %d => Out port: %d Out HopID: %d\n", + hop->in_hop_index, regs->out_port, regs->next_hop); + tb_port_dbg(port, " Weight: %d Priority: %d Credits: %d Drop: %d PM: %d\n", + regs->weight, regs->priority, regs->initial_credits, + regs->drop_packages, regs->pmps); + tb_port_dbg(port, " Counter enabled: %d Counter index: %d\n", + regs->counter_enable, regs->counter); + tb_port_dbg(port, " Flow Control (In/Eg): %d/%d Shared Buffer (In/Eg): %d/%d\n", + regs->ingress_fc, regs->egress_fc, + regs->ingress_shared_buffer, regs->egress_shared_buffer); + tb_port_dbg(port, " Unknown1: %#x Unknown2: %#x Unknown3: %#x\n", + regs->unknown1, regs->unknown2, regs->unknown3); +} + +static struct tb_port *tb_path_find_dst_port(struct tb_port *src, int src_hopid, + int dst_hopid) +{ + struct tb_port *port, *out_port = NULL; + struct tb_regs_hop hop; + struct tb_switch *sw; + int i, ret, hopid; + + hopid = src_hopid; + port = src; + + for (i = 0; port && i < TB_PATH_MAX_HOPS; i++) { + sw = port->sw; + + ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hopid, 2); + if (ret) { + tb_port_warn(port, "failed to read path at %d\n", hopid); + return NULL; + } + + if (!hop.enable) + return NULL; + + out_port = &sw->ports[hop.out_port]; + hopid = hop.next_hop; + port = out_port->remote; + } + + return out_port && hopid == dst_hopid ? out_port : NULL; +} + +static int tb_path_find_src_hopid(struct tb_port *src, + const struct tb_port *dst, int dst_hopid) +{ + struct tb_port *out; + int i; + + for (i = TB_PATH_MIN_HOPID; i <= src->config.max_in_hop_id; i++) { + out = tb_path_find_dst_port(src, i, dst_hopid); + if (out == dst) + return i; + } + + return 0; +} + +/** + * tb_path_discover() - Discover a path + * @src: First input port of a path + * @src_hopid: Starting HopID of a path (%-1 if don't care) + * @dst: Expected destination port of the path (%NULL if don't care) + * @dst_hopid: HopID to the @dst (%-1 if don't care) + * @last: Last port is filled here if not %NULL + * @name: Name of the path + * @alloc_hopid: Allocate HopIDs for the ports + * + * Follows a path starting from @src and @src_hopid to the last output + * port of the path. Allocates HopIDs for the visited ports (if + * @alloc_hopid is true). Call tb_path_free() to release the path and + * allocated HopIDs when the path is not needed anymore. + * + * Note function discovers also incomplete paths so caller should check + * that the @dst port is the expected one. If it is not, the path can be + * cleaned up by calling tb_path_deactivate() before tb_path_free(). + * + * Return: Pointer to &struct tb_path, %NULL in case of failure. + */ +struct tb_path *tb_path_discover(struct tb_port *src, int src_hopid, + struct tb_port *dst, int dst_hopid, + struct tb_port **last, const char *name, + bool alloc_hopid) +{ + struct tb_port *out_port; + struct tb_regs_hop hop; + struct tb_path *path; + struct tb_switch *sw; + struct tb_port *p; + size_t num_hops; + int ret, i, h; + + if (src_hopid < 0 && dst) { + /* + * For incomplete paths the intermediate HopID can be + * different from the one used by the protocol adapter + * so in that case find a path that ends on @dst with + * matching @dst_hopid. That should give us the correct + * HopID for the @src. + */ + src_hopid = tb_path_find_src_hopid(src, dst, dst_hopid); + if (!src_hopid) + return NULL; + } + + p = src; + h = src_hopid; + num_hops = 0; + + for (i = 0; p && i < TB_PATH_MAX_HOPS; i++) { + sw = p->sw; + + ret = tb_port_read(p, &hop, TB_CFG_HOPS, 2 * h, 2); + if (ret) { + tb_port_warn(p, "failed to read path at %d\n", h); + return NULL; + } + + /* If the hop is not enabled we got an incomplete path */ + if (!hop.enable) + break; + + out_port = &sw->ports[hop.out_port]; + if (last) + *last = out_port; + + h = hop.next_hop; + p = out_port->remote; + num_hops++; + } + + path = kzalloc_flex(*path, hops, num_hops); + if (!path) + return NULL; + + path->path_length = num_hops; + + path->name = name; + path->tb = src->sw->tb; + path->activated = true; + path->alloc_hopid = alloc_hopid; + + tb_dbg(path->tb, "discovering %s path starting from %llx:%u\n", + path->name, tb_route(src->sw), src->port); + + p = src; + h = src_hopid; + + for (i = 0; i < num_hops; i++) { + int next_hop; + + sw = p->sw; + + ret = tb_port_read(p, &hop, TB_CFG_HOPS, 2 * h, 2); + if (ret) { + tb_port_warn(p, "failed to read path at %d\n", h); + goto err; + } + + if (alloc_hopid && tb_port_alloc_in_hopid(p, h, h) < 0) + goto err; + + out_port = &sw->ports[hop.out_port]; + next_hop = hop.next_hop; + + if (alloc_hopid && + tb_port_alloc_out_hopid(out_port, next_hop, next_hop) < 0) { + tb_port_release_in_hopid(p, h); + goto err; + } + + path->hops[i].in_port = p; + path->hops[i].in_hop_index = h; + path->hops[i].in_counter_index = -1; + path->hops[i].out_port = out_port; + path->hops[i].next_hop_index = next_hop; + + tb_dump_hop(&path->hops[i], &hop); + + h = next_hop; + p = out_port->remote; + } + + tb_dbg(path->tb, "path discovery complete\n"); + return path; + +err: + tb_port_warn(src, "failed to discover path starting at HopID %d\n", + src_hopid); + tb_path_free(path); + return NULL; +} + +/** + * tb_path_alloc() - allocate a thunderbolt path between two ports + * @tb: Domain pointer + * @src: Source port of the path + * @src_hopid: HopID used for the first ingress port in the path + * @dst: Destination port of the path + * @dst_hopid: HopID used for the last egress port in the path + * @link_nr: Preferred link if there are dual links on the path + * @name: Name of the path + * + * Creates path between two ports starting with given @src_hopid. Reserves + * HopIDs for each port (they can be different from @src_hopid depending on + * how many HopIDs each port already have reserved). If there are dual + * links on the path, prioritizes using @link_nr but takes into account + * that the lanes may be bonded. + * + * Return: Pointer to &struct tb_path, %NULL in case of failure. + */ +struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src, int src_hopid, + struct tb_port *dst, int dst_hopid, int link_nr, + const char *name) +{ + struct tb_port *in_port, *out_port, *first_port, *last_port; + int in_hopid, out_hopid; + struct tb_path *path; + size_t num_hops; + int i, ret; + + first_port = last_port = NULL; + i = 0; + tb_for_each_port_on_path(src, dst, in_port) { + if (!first_port) + first_port = in_port; + last_port = in_port; + i++; + } + + /* Check that src and dst are reachable */ + if (first_port != src || last_port != dst) + return NULL; + + /* Each hop takes two ports */ + num_hops = i / 2; + + path = kzalloc_flex(*path, hops, num_hops); + if (!path) + return NULL; + + path->path_length = num_hops; + path->alloc_hopid = true; + + in_hopid = src_hopid; + out_port = NULL; + + for (i = 0; i < num_hops; i++) { + in_port = tb_next_port_on_path(src, dst, out_port); + if (!in_port) + goto err; + + /* When lanes are bonded primary link must be used */ + if (!in_port->bonded && in_port->dual_link_port && + in_port->link_nr != link_nr) + in_port = in_port->dual_link_port; + + ret = tb_port_alloc_in_hopid(in_port, in_hopid, in_hopid); + if (ret < 0) + goto err; + in_hopid = ret; + + out_port = tb_next_port_on_path(src, dst, in_port); + if (!out_port) + goto err; + + /* + * Pick up right port when going from non-bonded to + * bonded or from bonded to non-bonded. + */ + if (out_port->dual_link_port) { + if (!in_port->bonded && out_port->bonded && + out_port->link_nr) { + /* + * Use primary link when going from + * non-bonded to bonded. + */ + out_port = out_port->dual_link_port; + } else if (!out_port->bonded && + out_port->link_nr != link_nr) { + /* + * If out port is not bonded follow + * link_nr. + */ + out_port = out_port->dual_link_port; + } + } + + if (i == num_hops - 1) + ret = tb_port_alloc_out_hopid(out_port, dst_hopid, + dst_hopid); + else + ret = tb_port_alloc_out_hopid(out_port, -1, -1); + + if (ret < 0) + goto err; + out_hopid = ret; + + path->hops[i].in_hop_index = in_hopid; + path->hops[i].in_port = in_port; + path->hops[i].in_counter_index = -1; + path->hops[i].out_port = out_port; + path->hops[i].next_hop_index = out_hopid; + + in_hopid = out_hopid; + } + + path->tb = tb; + path->name = name; + + return path; + +err: + tb_path_free(path); + return NULL; +} + +/** + * tb_path_free() - free a path + * @path: Path to free + * + * Frees a path. The path does not need to be deactivated. + */ +void tb_path_free(struct tb_path *path) +{ + if (path->alloc_hopid) { + int i; + + for (i = 0; i < path->path_length; i++) { + const struct tb_path_hop *hop = &path->hops[i]; + + if (hop->in_port) + tb_port_release_in_hopid(hop->in_port, + hop->in_hop_index); + if (hop->out_port) + tb_port_release_out_hopid(hop->out_port, + hop->next_hop_index); + } + } + + kfree(path); +} + +static void __tb_path_deallocate_nfc(struct tb_path *path, int first_hop) +{ + int i, res; + for (i = first_hop; i < path->path_length; i++) { + res = tb_port_add_nfc_credits(path->hops[i].in_port, + -path->hops[i].nfc_credits); + if (res) + tb_port_warn(path->hops[i].in_port, + "nfc credits deallocation failed for hop %d\n", + i); + } +} + +static int __tb_path_deactivate_hop(struct tb_port *port, int hop_index, + bool clear_fc) +{ + struct tb_regs_hop hop; + ktime_t timeout; + int ret; + + /* Disable the path */ + ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2); + if (ret) + return ret; + + /* Already disabled */ + if (!hop.enable) + return 0; + + hop.enable = 0; + + ret = tb_port_write(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2); + if (ret) + return ret; + + /* Wait until it is drained */ + timeout = ktime_add_ms(ktime_get(), 500); + do { + ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2); + if (ret) + return ret; + + if (!hop.pending) { + if (clear_fc) { + /* + * Clear flow control. Protocol adapters + * IFC and ISE bits are vendor defined + * in the USB4 spec so we clear them + * only for pre-USB4 adapters. + */ + if (tb_port_is_null(port) || + !tb_switch_is_usb4(port->sw)) { + hop.ingress_fc = 0; + hop.ingress_shared_buffer = 0; + } + hop.egress_fc = 0; + hop.egress_shared_buffer = 0; + + return tb_port_write(port, &hop, TB_CFG_HOPS, + 2 * hop_index, 2); + } + + return 0; + } + + usleep_range(10, 20); + } while (ktime_before(ktime_get(), timeout)); + + return -ETIMEDOUT; +} + +/** + * tb_path_deactivate_hop() - Deactivate one path in path config space + * @port: Lane or protocol adapter + * @hop_index: HopID of the path to be cleared + * + * This deactivates or clears a single path config space entry at + * @hop_index. + * + * Return: %0 on success, negative errno otherwise. + */ +int tb_path_deactivate_hop(struct tb_port *port, int hop_index) +{ + return __tb_path_deactivate_hop(port, hop_index, true); +} + +static void __tb_path_deactivate_hops(struct tb_path *path, int first_hop) +{ + int i, res; + + for (i = first_hop; i < path->path_length; i++) { + res = __tb_path_deactivate_hop(path->hops[i].in_port, + path->hops[i].in_hop_index, + path->clear_fc); + if (res && res != -ENODEV) + tb_port_warn(path->hops[i].in_port, + "hop deactivation failed for hop %d, index %d\n", + i, path->hops[i].in_hop_index); + } +} + +void tb_path_deactivate(struct tb_path *path) +{ + if (!path->activated) { + tb_WARN(path->tb, "trying to deactivate an inactive path\n"); + return; + } + tb_dbg(path->tb, + "deactivating %s path from %llx:%u to %llx:%u\n", + path->name, tb_route(path->hops[0].in_port->sw), + path->hops[0].in_port->port, + tb_route(path->hops[path->path_length - 1].out_port->sw), + path->hops[path->path_length - 1].out_port->port); + __tb_path_deactivate_hops(path, 0); + __tb_path_deallocate_nfc(path, 0); + path->activated = false; +} + +/** + * tb_path_activate() - activate a path + * @path: Path to activate + * + * Activate a path starting with the first hop and ending on the last hop. The + * caller must fill path->hops before calling tb_path_activate(). + * + * Return: %0 on success, negative errno otherwise. + */ +int tb_path_activate(struct tb_path *path) +{ + int i, res; + enum tb_path_port out_mask, in_mask; + if (path->activated) { + tb_WARN(path->tb, "trying to activate already activated path\n"); + return -EINVAL; + } + + tb_dbg(path->tb, + "activating %s path from %llx:%u to %llx:%u\n", + path->name, tb_route(path->hops[0].in_port->sw), + path->hops[0].in_port->port, + tb_route(path->hops[path->path_length - 1].out_port->sw), + path->hops[path->path_length - 1].out_port->port); + + /* Clear counters. */ + for (i = path->path_length - 1; i >= 0; i--) { + if (path->hops[i].in_counter_index == -1) + continue; + res = tb_port_clear_counter(path->hops[i].in_port, + path->hops[i].in_counter_index); + if (res) + goto err; + } + + /* Add non flow controlled credits. */ + for (i = path->path_length - 1; i >= 0; i--) { + res = tb_port_add_nfc_credits(path->hops[i].in_port, + path->hops[i].nfc_credits); + if (res) { + __tb_path_deallocate_nfc(path, i); + goto err; + } + } + + /* Activate hops. */ + for (i = 0; i < path->path_length; i++) { + struct tb_regs_hop hop = { 0 }; + + /* If it is left active deactivate it first */ + __tb_path_deactivate_hop(path->hops[i].in_port, + path->hops[i].in_hop_index, path->clear_fc); + + /* Needed for USB4 routers, read path config space before write */ + res = tb_port_read(path->hops[i].in_port, &hop, TB_CFG_HOPS, + 2 * path->hops[i].in_hop_index, 2); + if (res) + goto err; + + hop.next_hop = path->hops[i].next_hop_index; + hop.out_port = path->hops[i].out_port->port; + hop.pmps = path->hops[i].pm_support; + hop.unknown1 = 0; + hop.enable = 1; + + out_mask = (i == path->path_length - 1) ? + TB_PATH_DESTINATION : TB_PATH_INTERNAL; + in_mask = (i == 0) ? TB_PATH_SOURCE : TB_PATH_INTERNAL; + hop.weight = path->weight; + hop.unknown2 = 0; + hop.priority = path->priority; + hop.drop_packages = path->drop_packages; + hop.counter = path->hops[i].in_counter_index; + hop.counter_enable = path->hops[i].in_counter_index != -1; + hop.egress_fc = path->egress_fc_enable & out_mask; + hop.egress_shared_buffer = path->egress_shared_buffer & out_mask; + /* + * Protocol adapters IFC and ISE bits, and Path Credits + * Allocated are vendor defined in the USB4 spec so we + * program them only for pre-USB4 and lane adapters. + */ + if (tb_port_is_null(path->hops[i].in_port) || + !tb_switch_is_usb4(path->hops[i].in_port->sw)) { + hop.initial_credits = path->hops[i].initial_credits; + hop.ingress_fc = path->ingress_fc_enable & in_mask; + hop.ingress_shared_buffer = + path->ingress_shared_buffer & in_mask; + } + + hop.unknown3 = 0; + + tb_port_dbg(path->hops[i].in_port, "Writing hop %d\n", i); + tb_dump_hop(&path->hops[i], &hop); + res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS, + 2 * path->hops[i].in_hop_index, 2); + if (res) { + __tb_path_deactivate_hops(path, 0); + __tb_path_deallocate_nfc(path, 0); + goto err; + } + } + path->activated = true; + tb_dbg(path->tb, "%s path activation complete\n", path->name); + return 0; +err: + tb_warn(path->tb, "%s path activation failed: %d\n", path->name, res); + return res; +} + +/** + * tb_path_is_invalid() - check whether any ports on the path are invalid + * @path: Path to check + * + * Return: %true if the path is invalid, %false otherwise. + */ +bool tb_path_is_invalid(struct tb_path *path) +{ + int i = 0; + for (i = 0; i < path->path_length; i++) { + if (path->hops[i].in_port->sw->is_unplugged) + return true; + if (path->hops[i].out_port->sw->is_unplugged) + return true; + } + return false; +} + +/** + * tb_path_port_on_path() - Does the path go through certain port + * @path: Path to check + * @port: Switch to check + * + * Goes over all hops on path and checks if @port is any of them. + * Direction does not matter. + * + * Return: %true if port is on the path, %false otherwise. + */ +bool tb_path_port_on_path(const struct tb_path *path, const struct tb_port *port) +{ + int i; + + for (i = 0; i < path->path_length; i++) { + if (path->hops[i].in_port == port || + path->hops[i].out_port == port) + return true; + } + + return false; +} -- cgit v1.3.1