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/reset/reset-ti-sci.c | 259 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 259 insertions(+) create mode 100644 drivers/reset/reset-ti-sci.c (limited to 'drivers/reset/reset-ti-sci.c') diff --git a/drivers/reset/reset-ti-sci.c b/drivers/reset/reset-ti-sci.c new file mode 100644 index 000000000..1dc5b766a --- /dev/null +++ b/drivers/reset/reset-ti-sci.c @@ -0,0 +1,259 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Texas Instrument's System Control Interface (TI-SCI) reset driver + * + * Copyright (C) 2015-2017 Texas Instruments Incorporated - https://www.ti.com/ + * Andrew F. Davis + */ + +#include +#include +#include +#include +#include +#include +#include + +/** + * struct ti_sci_reset_control - reset control structure + * @dev_id: SoC-specific device identifier + * @reset_mask: reset mask to use for toggling reset + * @lock: synchronize reset_mask read-modify-writes + */ +struct ti_sci_reset_control { + u32 dev_id; + u32 reset_mask; + struct mutex lock; +}; + +/** + * struct ti_sci_reset_data - reset controller information structure + * @rcdev: reset controller entity + * @dev: reset controller device pointer + * @sci: TI SCI handle used for communication with system controller + * @idr: idr structure for mapping ids to reset control structures + */ +struct ti_sci_reset_data { + struct reset_controller_dev rcdev; + struct device *dev; + const struct ti_sci_handle *sci; + struct idr idr; +}; + +#define to_ti_sci_reset_data(p) \ + container_of((p), struct ti_sci_reset_data, rcdev) + +/** + * ti_sci_reset_set() - program a device's reset + * @rcdev: reset controller entity + * @id: ID of the reset to toggle + * @assert: boolean flag to indicate assert or deassert + * + * This is a common internal function used to assert or deassert a device's + * reset using the TI SCI protocol. The device's reset is asserted if the + * @assert argument is true, or deasserted if @assert argument is false. + * The mechanism itself is a read-modify-write procedure, the current device + * reset register is read using a TI SCI device operation, the new value is + * set or un-set using the reset's mask, and the new reset value written by + * using another TI SCI device operation. + * + * Return: 0 for successful request, else a corresponding error value + */ +static int ti_sci_reset_set(struct reset_controller_dev *rcdev, + unsigned long id, bool assert) +{ + struct ti_sci_reset_data *data = to_ti_sci_reset_data(rcdev); + const struct ti_sci_handle *sci = data->sci; + const struct ti_sci_dev_ops *dev_ops = &sci->ops.dev_ops; + struct ti_sci_reset_control *control; + u32 reset_state; + int ret; + + control = idr_find(&data->idr, id); + if (!control) + return -EINVAL; + + mutex_lock(&control->lock); + + ret = dev_ops->get_device_resets(sci, control->dev_id, &reset_state); + if (ret) + goto out; + + if (assert) + reset_state |= control->reset_mask; + else + reset_state &= ~control->reset_mask; + + ret = dev_ops->set_device_resets(sci, control->dev_id, reset_state); +out: + mutex_unlock(&control->lock); + + return ret; +} + +/** + * ti_sci_reset_assert() - assert device reset + * @rcdev: reset controller entity + * @id: ID of the reset to be asserted + * + * This function implements the reset driver op to assert a device's reset + * using the TI SCI protocol. This invokes the function ti_sci_reset_set() + * with the corresponding parameters as passed in, but with the @assert + * argument set to true for asserting the reset. + * + * Return: 0 for successful request, else a corresponding error value + */ +static int ti_sci_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return ti_sci_reset_set(rcdev, id, true); +} + +/** + * ti_sci_reset_deassert() - deassert device reset + * @rcdev: reset controller entity + * @id: ID of the reset to be deasserted + * + * This function implements the reset driver op to deassert a device's reset + * using the TI SCI protocol. This invokes the function ti_sci_reset_set() + * with the corresponding parameters as passed in, but with the @assert + * argument set to false for deasserting the reset. + * + * Return: 0 for successful request, else a corresponding error value + */ +static int ti_sci_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return ti_sci_reset_set(rcdev, id, false); +} + +/** + * ti_sci_reset_status() - check device reset status + * @rcdev: reset controller entity + * @id: ID of reset to be checked + * + * This function implements the reset driver op to return the status of a + * device's reset using the TI SCI protocol. The reset register value is read + * by invoking the TI SCI device operation .get_device_resets(), and the + * status of the specific reset is extracted and returned using this reset's + * reset mask. + * + * Return: 0 if reset is deasserted, or a non-zero value if reset is asserted + */ +static int ti_sci_reset_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct ti_sci_reset_data *data = to_ti_sci_reset_data(rcdev); + const struct ti_sci_handle *sci = data->sci; + const struct ti_sci_dev_ops *dev_ops = &sci->ops.dev_ops; + struct ti_sci_reset_control *control; + u32 reset_state; + int ret; + + control = idr_find(&data->idr, id); + if (!control) + return -EINVAL; + + ret = dev_ops->get_device_resets(sci, control->dev_id, &reset_state); + if (ret) + return ret; + + return reset_state & control->reset_mask; +} + +static const struct reset_control_ops ti_sci_reset_ops = { + .assert = ti_sci_reset_assert, + .deassert = ti_sci_reset_deassert, + .status = ti_sci_reset_status, +}; + +/** + * ti_sci_reset_of_xlate() - translate a set of OF arguments to a reset ID + * @rcdev: reset controller entity + * @reset_spec: OF reset argument specifier + * + * This function performs the translation of the reset argument specifier + * values defined in a reset consumer device node. The function allocates a + * reset control structure for that device reset, and will be used by the + * driver for performing any reset functions on that reset. An idr structure + * is allocated and used to map to the reset control structure. This idr + * is used by the driver to do reset lookups. + * + * Return: 0 for successful request, else a corresponding error value + */ +static int ti_sci_reset_of_xlate(struct reset_controller_dev *rcdev, + const struct of_phandle_args *reset_spec) +{ + struct ti_sci_reset_data *data = to_ti_sci_reset_data(rcdev); + struct ti_sci_reset_control *control; + + if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells)) + return -EINVAL; + + control = devm_kzalloc(data->dev, sizeof(*control), GFP_KERNEL); + if (!control) + return -ENOMEM; + + control->dev_id = reset_spec->args[0]; + control->reset_mask = reset_spec->args[1]; + mutex_init(&control->lock); + + return idr_alloc(&data->idr, control, 0, 0, GFP_KERNEL); +} + +static const struct of_device_id ti_sci_reset_of_match[] = { + { .compatible = "ti,sci-reset", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, ti_sci_reset_of_match); + +static int ti_sci_reset_probe(struct platform_device *pdev) +{ + struct ti_sci_reset_data *data; + + if (!pdev->dev.of_node) + return -ENODEV; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->sci = devm_ti_sci_get_handle(&pdev->dev); + if (IS_ERR(data->sci)) + return PTR_ERR(data->sci); + + data->rcdev.ops = &ti_sci_reset_ops; + data->rcdev.owner = THIS_MODULE; + data->rcdev.of_node = pdev->dev.of_node; + data->rcdev.of_reset_n_cells = 2; + data->rcdev.of_xlate = ti_sci_reset_of_xlate; + data->dev = &pdev->dev; + idr_init(&data->idr); + + platform_set_drvdata(pdev, data); + + return reset_controller_register(&data->rcdev); +} + +static void ti_sci_reset_remove(struct platform_device *pdev) +{ + struct ti_sci_reset_data *data = platform_get_drvdata(pdev); + + reset_controller_unregister(&data->rcdev); + + idr_destroy(&data->idr); +} + +static struct platform_driver ti_sci_reset_driver = { + .probe = ti_sci_reset_probe, + .remove = ti_sci_reset_remove, + .driver = { + .name = "ti-sci-reset", + .of_match_table = ti_sci_reset_of_match, + }, +}; +module_platform_driver(ti_sci_reset_driver); + +MODULE_AUTHOR("Andrew F. Davis "); +MODULE_DESCRIPTION("TI System Control Interface (TI SCI) Reset driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1