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/retimer.c | 600 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 600 insertions(+) create mode 100644 drivers/thunderbolt/retimer.c (limited to 'drivers/thunderbolt/retimer.c') diff --git a/drivers/thunderbolt/retimer.c b/drivers/thunderbolt/retimer.c new file mode 100644 index 000000000..b1e8d9d64 --- /dev/null +++ b/drivers/thunderbolt/retimer.c @@ -0,0 +1,600 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Thunderbolt/USB4 retimer support. + * + * Copyright (C) 2020, Intel Corporation + * Authors: Kranthi Kuntala + * Mika Westerberg + */ + +#include +#include +#include + +#include "sb_regs.h" +#include "tb.h" + +#if IS_ENABLED(CONFIG_USB4_DEBUGFS_MARGINING) +#define TB_MAX_RETIMER_INDEX 6 +#else +#define TB_MAX_RETIMER_INDEX 2 +#endif + +/** + * tb_retimer_nvm_read() - Read contents of retimer NVM + * @rt: Retimer device + * @address: NVM address (in bytes) to start reading + * @buf: Data read from NVM is stored here + * @size: Number of bytes to read + * + * Reads retimer NVM and copies the contents to @buf. + * + * Return: %0 if the read was successful, negative errno in case of failure. + */ +int tb_retimer_nvm_read(struct tb_retimer *rt, unsigned int address, void *buf, + size_t size) +{ + return usb4_port_retimer_nvm_read(rt->port, rt->index, address, buf, size); +} + +static int nvm_read(void *priv, unsigned int offset, void *val, size_t bytes) +{ + struct tb_nvm *nvm = priv; + struct tb_retimer *rt = tb_to_retimer(nvm->dev); + int ret; + + pm_runtime_get_sync(&rt->dev); + + if (!mutex_trylock(&rt->tb->lock)) { + ret = restart_syscall(); + goto out; + } + + ret = tb_retimer_nvm_read(rt, offset, val, bytes); + mutex_unlock(&rt->tb->lock); + +out: + pm_runtime_mark_last_busy(&rt->dev); + pm_runtime_put_autosuspend(&rt->dev); + + return ret; +} + +static int nvm_write(void *priv, unsigned int offset, void *val, size_t bytes) +{ + struct tb_nvm *nvm = priv; + struct tb_retimer *rt = tb_to_retimer(nvm->dev); + int ret = 0; + + if (!mutex_trylock(&rt->tb->lock)) + return restart_syscall(); + + ret = tb_nvm_write_buf(nvm, offset, val, bytes); + mutex_unlock(&rt->tb->lock); + + return ret; +} + +static int tb_retimer_nvm_add(struct tb_retimer *rt) +{ + struct tb_nvm *nvm; + int ret; + + nvm = tb_nvm_alloc(&rt->dev); + if (IS_ERR(nvm)) { + ret = PTR_ERR(nvm) == -EOPNOTSUPP ? 0 : PTR_ERR(nvm); + goto err_nvm; + } + + ret = tb_nvm_read_version(nvm); + if (ret) + goto err_nvm; + + ret = tb_nvm_add_active(nvm, nvm_read); + if (ret) + goto err_nvm; + + if (!rt->no_nvm_upgrade) { + ret = tb_nvm_add_non_active(nvm, nvm_write); + if (ret) + goto err_nvm; + } + + rt->nvm = nvm; + dev_dbg(&rt->dev, "NVM version %x.%x\n", nvm->major, nvm->minor); + return 0; + +err_nvm: + dev_dbg(&rt->dev, "NVM upgrade disabled\n"); + rt->no_nvm_upgrade = true; + if (!IS_ERR(nvm)) + tb_nvm_free(nvm); + + return ret; +} + +static int tb_retimer_nvm_validate_and_write(struct tb_retimer *rt) +{ + unsigned int image_size; + const u8 *buf; + int ret; + + ret = tb_nvm_validate(rt->nvm); + if (ret) + return ret; + + buf = rt->nvm->buf_data_start; + image_size = rt->nvm->buf_data_size; + + ret = usb4_port_retimer_nvm_write(rt->port, rt->index, 0, buf, + image_size); + if (ret) + return ret; + + rt->nvm->flushed = true; + return 0; +} + +static int tb_retimer_nvm_authenticate(struct tb_retimer *rt, bool auth_only) +{ + u32 status; + int ret; + + if (auth_only) { + ret = usb4_port_retimer_nvm_set_offset(rt->port, rt->index, 0); + if (ret) + return ret; + } + + ret = usb4_port_retimer_nvm_authenticate(rt->port, rt->index); + if (ret) + return ret; + + usleep_range(100, 150); + + /* + * Check the status now if we still can access the retimer. It + * is expected that the below fails. + */ + ret = usb4_port_retimer_nvm_authenticate_status(rt->port, rt->index, + &status); + if (!ret) { + rt->auth_status = status; + return status ? -EINVAL : 0; + } + + return 0; +} + +static ssize_t device_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tb_retimer *rt = tb_to_retimer(dev); + + return sysfs_emit(buf, "%#x\n", rt->device); +} +static DEVICE_ATTR_RO(device); + +static ssize_t nvm_authenticate_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tb_retimer *rt = tb_to_retimer(dev); + int ret; + + if (!mutex_trylock(&rt->tb->lock)) + return restart_syscall(); + + if (!rt->nvm) + ret = -EAGAIN; + else + ret = sysfs_emit(buf, "%#x\n", rt->auth_status); + + mutex_unlock(&rt->tb->lock); + + return ret; +} + +static void tb_retimer_nvm_authenticate_status(struct tb_port *port, u32 *status) +{ + int i; + + tb_port_dbg(port, "reading NVM authentication status of retimers\n"); + + /* + * Before doing anything else, read the authentication status. + * If the retimer has it set, store it for the new retimer + * device instance. + */ + for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++) { + if (usb4_port_retimer_nvm_authenticate_status(port, i, &status[i])) + break; + } +} + +static void tb_retimer_set_inbound_sbtx(struct tb_port *port) +{ + int i; + + /* + * When USB4 port is online sideband communications are + * already up. + */ + if (!usb4_port_device_is_offline(port->usb4)) + return; + + tb_port_dbg(port, "enabling sideband transactions\n"); + + for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++) + usb4_port_retimer_set_inbound_sbtx(port, i); +} + +static void tb_retimer_unset_inbound_sbtx(struct tb_port *port) +{ + int i; + + /* + * When USB4 port is offline we need to keep the sideband + * communications up to make it possible to communicate with + * the connected retimers. + */ + if (usb4_port_device_is_offline(port->usb4)) + return; + + tb_port_dbg(port, "disabling sideband transactions\n"); + + for (i = TB_MAX_RETIMER_INDEX; i >= 1; i--) { + if (usb4_port_retimer_unset_inbound_sbtx(port, i)) + break; + } +} + +static ssize_t nvm_authenticate_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct tb_retimer *rt = tb_to_retimer(dev); + int val, ret; + + pm_runtime_get_sync(&rt->dev); + + if (!mutex_trylock(&rt->tb->lock)) { + ret = restart_syscall(); + goto exit_rpm; + } + + if (!rt->nvm) { + ret = -EAGAIN; + goto exit_unlock; + } + + ret = kstrtoint(buf, 10, &val); + if (ret) + goto exit_unlock; + + /* Always clear status */ + rt->auth_status = 0; + + if (val) { + /* + * When NVM authentication starts the retimer is not + * accessible so calling tb_retimer_unset_inbound_sbtx() + * will fail and therefore we do not call it. Exception + * is when the validation fails or we only write the new + * NVM image without authentication. + */ + tb_retimer_set_inbound_sbtx(rt->port); + if (val == AUTHENTICATE_ONLY) { + ret = tb_retimer_nvm_authenticate(rt, true); + } else { + if (!rt->nvm->flushed) { + if (!rt->nvm->buf) { + ret = -EINVAL; + goto exit_unlock; + } + + ret = tb_retimer_nvm_validate_and_write(rt); + if (ret || val == WRITE_ONLY) + goto exit_unlock; + } + if (val == WRITE_AND_AUTHENTICATE) + ret = tb_retimer_nvm_authenticate(rt, false); + } + } + +exit_unlock: + if (ret || val == WRITE_ONLY) + tb_retimer_unset_inbound_sbtx(rt->port); + mutex_unlock(&rt->tb->lock); +exit_rpm: + pm_runtime_mark_last_busy(&rt->dev); + pm_runtime_put_autosuspend(&rt->dev); + + if (ret) + return ret; + return count; +} +static DEVICE_ATTR_RW(nvm_authenticate); + +static ssize_t nvm_version_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tb_retimer *rt = tb_to_retimer(dev); + int ret; + + if (!mutex_trylock(&rt->tb->lock)) + return restart_syscall(); + + if (!rt->nvm) + ret = -EAGAIN; + else + ret = sysfs_emit(buf, "%x.%x\n", rt->nvm->major, rt->nvm->minor); + + mutex_unlock(&rt->tb->lock); + return ret; +} +static DEVICE_ATTR_RO(nvm_version); + +static ssize_t vendor_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tb_retimer *rt = tb_to_retimer(dev); + + return sysfs_emit(buf, "%#x\n", rt->vendor); +} +static DEVICE_ATTR_RO(vendor); + +static umode_t retimer_is_visible(struct kobject *kobj, struct attribute *attr, + int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct tb_retimer *rt = tb_to_retimer(dev); + + if (attr == &dev_attr_nvm_authenticate.attr || + attr == &dev_attr_nvm_version.attr) + return rt->no_nvm_upgrade ? 0 : attr->mode; + + return attr->mode; +} + +static struct attribute *retimer_attrs[] = { + &dev_attr_device.attr, + &dev_attr_nvm_authenticate.attr, + &dev_attr_nvm_version.attr, + &dev_attr_vendor.attr, + NULL +}; + +static const struct attribute_group retimer_group = { + .is_visible = retimer_is_visible, + .attrs = retimer_attrs, +}; + +static const struct attribute_group *retimer_groups[] = { + &retimer_group, + NULL +}; + +static void tb_retimer_release(struct device *dev) +{ + struct tb_retimer *rt = tb_to_retimer(dev); + + kfree(rt); +} + +const struct device_type tb_retimer_type = { + .name = "thunderbolt_retimer", + .groups = retimer_groups, + .release = tb_retimer_release, +}; + +static int tb_retimer_add(struct tb_port *port, u8 index, u32 auth_status, + bool on_board) +{ + struct tb_retimer *rt; + u32 vendor, device; + int ret; + + ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index, + USB4_SB_VENDOR_ID, &vendor, sizeof(vendor)); + if (ret) { + if (ret != -ENODEV) + tb_port_warn(port, "failed read retimer VendorId: %d\n", ret); + return ret; + } + + ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index, + USB4_SB_PRODUCT_ID, &device, sizeof(device)); + if (ret) { + if (ret != -ENODEV) + tb_port_warn(port, "failed read retimer ProductId: %d\n", ret); + return ret; + } + + + rt = kzalloc_obj(*rt); + if (!rt) + return -ENOMEM; + + rt->index = index; + rt->vendor = vendor; + rt->device = device; + rt->auth_status = auth_status; + rt->port = port; + rt->tb = port->sw->tb; + + /* + * Only support NVM upgrade for on-board retimers. The retimers + * on the other side of the connection. + */ + if (!on_board || usb4_port_retimer_nvm_sector_size(port, index) <= 0) + rt->no_nvm_upgrade = true; + + rt->dev.parent = &port->usb4->dev; + rt->dev.bus = &tb_bus_type; + rt->dev.type = &tb_retimer_type; + dev_set_name(&rt->dev, "%s:%u.%u", dev_name(&port->sw->dev), + port->port, index); + + ret = device_register(&rt->dev); + if (ret) { + dev_err(&rt->dev, "failed to register retimer: %d\n", ret); + put_device(&rt->dev); + return ret; + } + + ret = tb_retimer_nvm_add(rt); + if (ret) { + dev_err(&rt->dev, "failed to add NVM devices: %d\n", ret); + device_unregister(&rt->dev); + return ret; + } + + dev_info(&rt->dev, "new retimer found, vendor=%#x device=%#x\n", + rt->vendor, rt->device); + + pm_runtime_no_callbacks(&rt->dev); + pm_runtime_set_active(&rt->dev); + pm_runtime_enable(&rt->dev); + pm_runtime_set_autosuspend_delay(&rt->dev, TB_AUTOSUSPEND_DELAY); + pm_runtime_mark_last_busy(&rt->dev); + pm_runtime_use_autosuspend(&rt->dev); + + tb_retimer_debugfs_init(rt); + return 0; +} + +static void tb_retimer_remove(struct tb_retimer *rt) +{ + dev_info(&rt->dev, "retimer disconnected\n"); + tb_retimer_debugfs_remove(rt); + tb_nvm_free(rt->nvm); + device_unregister(&rt->dev); +} + +struct tb_retimer_lookup { + const struct tb_port *port; + u8 index; +}; + +static int retimer_match(struct device *dev, const void *data) +{ + const struct tb_retimer_lookup *lookup = data; + struct tb_retimer *rt = tb_to_retimer(dev); + + return rt && rt->port == lookup->port && rt->index == lookup->index; +} + +static struct tb_retimer *tb_port_find_retimer(struct tb_port *port, u8 index) +{ + struct tb_retimer_lookup lookup = { .port = port, .index = index }; + struct device *dev; + + dev = device_find_child(&port->usb4->dev, &lookup, retimer_match); + if (dev) + return tb_to_retimer(dev); + + return NULL; +} + +/** + * tb_retimer_scan() - Scan for on-board retimers under port + * @port: USB4 port to scan + * @add: If true also registers found retimers + * + * Brings the sideband into a state where retimers can be accessed. + * Then tries to enumerate on-board retimers connected to @port. Found + * retimers are registered as children of @port if @add is set. Does + * not scan for cable retimers for now. + * + * Return: %0 on success, negative errno otherwise. + */ +int tb_retimer_scan(struct tb_port *port, bool add) +{ + u32 status[TB_MAX_RETIMER_INDEX + 1] = {}; + int ret, i, max, last_idx = 0; + + /* + * Send broadcast RT to make sure retimer indices facing this + * port are set. + */ + ret = usb4_port_enumerate_retimers(port); + if (ret) + return ret; + + /* + * Immediately after sending enumerate retimers read the + * authentication status of each retimer. + */ + tb_retimer_nvm_authenticate_status(port, status); + + /* + * Enable sideband channel for each retimer. We can do this + * regardless whether there is device connected or not. + */ + tb_retimer_set_inbound_sbtx(port); + + for (max = 1, i = 1; i <= TB_MAX_RETIMER_INDEX; i++) { + /* + * Last retimer is true only for the last on-board + * retimer (the one connected directly to the Type-C + * port). + */ + ret = usb4_port_retimer_is_last(port, i); + if (ret > 0) + last_idx = i; + else if (ret < 0) + break; + + max = i; + } + + ret = 0; + if (!IS_ENABLED(CONFIG_USB4_DEBUGFS_MARGINING)) + max = min(last_idx, max); + + /* Add retimers if they do not exist already */ + for (i = 1; i <= max; i++) { + struct tb_retimer *rt; + + /* Skip cable retimers */ + if (usb4_port_retimer_is_cable(port, i)) + continue; + + rt = tb_port_find_retimer(port, i); + if (rt) { + put_device(&rt->dev); + } else if (add) { + ret = tb_retimer_add(port, i, status[i], i <= last_idx); + if (ret && ret != -EOPNOTSUPP) + break; + } + } + + tb_retimer_unset_inbound_sbtx(port); + return ret; +} + +static int remove_retimer(struct device *dev, void *data) +{ + struct tb_retimer *rt = tb_to_retimer(dev); + struct tb_port *port = data; + + if (rt && rt->port == port) + tb_retimer_remove(rt); + return 0; +} + +/** + * tb_retimer_remove_all() - Remove all retimers under port + * @port: USB4 port whose retimers to remove + * + * This removes all previously added retimers under @port. + */ +void tb_retimer_remove_all(struct tb_port *port) +{ + struct usb4_port *usb4; + + usb4 = port->usb4; + if (usb4) + device_for_each_child_reverse(&usb4->dev, port, + remove_retimer); +} -- cgit v1.3.1