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/mailbox/exynos-mailbox.c | 205 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 205 insertions(+) create mode 100644 drivers/mailbox/exynos-mailbox.c (limited to 'drivers/mailbox/exynos-mailbox.c') diff --git a/drivers/mailbox/exynos-mailbox.c b/drivers/mailbox/exynos-mailbox.c new file mode 100644 index 000000000..ff75c1c76 --- /dev/null +++ b/drivers/mailbox/exynos-mailbox.c @@ -0,0 +1,205 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2020 Samsung Electronics Co., Ltd. + * Copyright 2020 Google LLC. + * Copyright 2024 Linaro Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define EXYNOS_MBOX_INTMR0 0x28 /* Interrupt Mask Register 0 */ +#define EXYNOS_MBOX_INTGR1 0x40 /* Interrupt Generation Register 1 */ + +#define EXYNOS_MBOX_INTMR0_MASK GENMASK(15, 0) +#define EXYNOS_MBOX_INTGR1_MASK GENMASK(15, 0) + +#define EXYNOS_MBOX_CHAN_COUNT HWEIGHT32(EXYNOS_MBOX_INTGR1_MASK) + +#define EXYNOS850_MBOX_INTGR0 0x8 /* Interrupt Generation Register 0 */ +#define EXYNOS850_MBOX_INTMR1 0x24 /* Interrupt Mask Register 1 */ + +#define EXYNOS850_MBOX_INTMR1_MASK GENMASK(15, 0) +#define EXYNOS850_MBOX_INTGR0_MASK GENMASK(31, 16) + +#define EXYNOS850_MBOX_CHAN_COUNT HWEIGHT32(EXYNOS850_MBOX_INTGR0_MASK) + +/** + * struct exynos_mbox_driver_data - platform-specific mailbox configuration. + * @intgr: offset to the IRQ generation register, doorbell + * to APM co-processor. + * @intgr_shift: shift to apply to the value written to IRQ generation + * register. + * @intmr: offset to the IRQ mask register. + * @intmr_mask: value to write to the mask register to mask out all + * interrupts. + * @num_chans: number of channels the mailbox can support (hardware + * capability). + */ +struct exynos_mbox_driver_data { + u32 intgr; + u32 intgr_shift; + u32 intmr; + u32 intmr_mask; + int num_chans; +}; + +/** + * struct exynos_mbox - driver's private data. + * @regs: mailbox registers base address. + * @mbox: pointer to the mailbox controller. + * @data: pointer to driver platform-specific data. + */ +struct exynos_mbox { + void __iomem *regs; + struct mbox_controller *mbox; + const struct exynos_mbox_driver_data *data; +}; + +static const struct exynos_mbox_driver_data exynos850_mbox_data = { + .intgr = EXYNOS850_MBOX_INTGR0, + .intgr_shift = 16, + .intmr = EXYNOS850_MBOX_INTMR1, + .intmr_mask = EXYNOS850_MBOX_INTMR1_MASK, + .num_chans = EXYNOS850_MBOX_CHAN_COUNT, +}; + +static const struct exynos_mbox_driver_data exynos_gs101_mbox_data = { + .intgr = EXYNOS_MBOX_INTGR1, + .intgr_shift = 0, + .intmr = EXYNOS_MBOX_INTMR0, + .intmr_mask = EXYNOS_MBOX_INTMR0_MASK, + .num_chans = EXYNOS_MBOX_CHAN_COUNT, +}; + +static int exynos_mbox_send_data(struct mbox_chan *chan, void *data) +{ + struct device *dev = chan->mbox->dev; + struct exynos_mbox *exynos_mbox = dev_get_drvdata(dev); + struct exynos_mbox_msg *msg = data; + + if (msg->chan_id >= exynos_mbox->mbox->num_chans) { + dev_err(dev, "Invalid channel ID %d\n", msg->chan_id); + return -EINVAL; + } + + if (msg->chan_type != EXYNOS_MBOX_CHAN_TYPE_DOORBELL) { + dev_err(dev, "Unsupported channel type [%d]\n", msg->chan_type); + return -EINVAL; + } + + /* Ring the doorbell */ + writel(BIT(msg->chan_id) << exynos_mbox->data->intgr_shift, + exynos_mbox->regs + exynos_mbox->data->intgr); + + return 0; +} + +static const struct mbox_chan_ops exynos_mbox_chan_ops = { + .send_data = exynos_mbox_send_data, +}; + +static struct mbox_chan *exynos_mbox_of_xlate(struct mbox_controller *mbox, + const struct of_phandle_args *sp) +{ + int i; + + if (sp->args_count != 0) + return ERR_PTR(-EINVAL); + + /* + * Return the first available channel. When we don't pass the + * channel ID from device tree, each channel populated by the driver is + * just a software construct or a virtual channel. We use 'void *data' + * in send_data() to pass the channel identifiers. + */ + for (i = 0; i < mbox->num_chans; i++) + if (mbox->chans[i].cl == NULL) + return &mbox->chans[i]; + return ERR_PTR(-EINVAL); +} + +static const struct of_device_id exynos_mbox_match[] = { + { + .compatible = "google,gs101-mbox", + .data = &exynos_gs101_mbox_data + }, + { + .compatible = "samsung,exynos850-mbox", + .data = &exynos850_mbox_data + }, + {}, +}; +MODULE_DEVICE_TABLE(of, exynos_mbox_match); + +static int exynos_mbox_probe(struct platform_device *pdev) +{ + const struct exynos_mbox_driver_data *data; + struct device *dev = &pdev->dev; + struct exynos_mbox *exynos_mbox; + struct mbox_controller *mbox; + struct mbox_chan *chans; + struct clk *pclk; + + data = device_get_match_data(&pdev->dev); + if (!data) + return -ENODEV; + + exynos_mbox = devm_kzalloc(dev, sizeof(*exynos_mbox), GFP_KERNEL); + if (!exynos_mbox) + return -ENOMEM; + + mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL); + if (!mbox) + return -ENOMEM; + + chans = devm_kcalloc(dev, data->num_chans, sizeof(*chans), GFP_KERNEL); + if (!chans) + return -ENOMEM; + + exynos_mbox->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(exynos_mbox->regs)) + return PTR_ERR(exynos_mbox->regs); + + pclk = devm_clk_get_enabled(dev, "pclk"); + if (IS_ERR(pclk)) + return dev_err_probe(dev, PTR_ERR(pclk), + "Failed to enable clock.\n"); + + exynos_mbox->data = data; + mbox->num_chans = data->num_chans; + mbox->chans = chans; + mbox->dev = dev; + mbox->ops = &exynos_mbox_chan_ops; + mbox->of_xlate = exynos_mbox_of_xlate; + + exynos_mbox->mbox = mbox; + + platform_set_drvdata(pdev, exynos_mbox); + + /* Mask out all interrupts. We support just polling channels for now. */ + writel(data->intmr_mask, exynos_mbox->regs + data->intmr); + + return devm_mbox_controller_register(dev, mbox); +} + +static struct platform_driver exynos_mbox_driver = { + .probe = exynos_mbox_probe, + .driver = { + .name = "exynos-acpm-mbox", + .of_match_table = exynos_mbox_match, + }, +}; +module_platform_driver(exynos_mbox_driver); + +MODULE_AUTHOR("Tudor Ambarus "); +MODULE_DESCRIPTION("Samsung Exynos mailbox driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1