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/clocksource/timer-lpc32xx.c | 310 ++++++++++++++++++++++++++++++++++++ 1 file changed, 310 insertions(+) create mode 100644 drivers/clocksource/timer-lpc32xx.c (limited to 'drivers/clocksource/timer-lpc32xx.c') diff --git a/drivers/clocksource/timer-lpc32xx.c b/drivers/clocksource/timer-lpc32xx.c new file mode 100644 index 000000000..68eae6378 --- /dev/null +++ b/drivers/clocksource/timer-lpc32xx.c @@ -0,0 +1,310 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Clocksource driver for NXP LPC32xx/18xx/43xx timer + * + * Copyright (C) 2015 Joachim Eastwood + * + * Based on: + * time-efm32 Copyright (C) 2013 Pengutronix + * mach-lpc32xx/timer.c Copyright (C) 2009 - 2010 NXP Semiconductors + */ + +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define LPC32XX_TIMER_IR 0x000 +#define LPC32XX_TIMER_IR_MR0INT BIT(0) +#define LPC32XX_TIMER_TCR 0x004 +#define LPC32XX_TIMER_TCR_CEN BIT(0) +#define LPC32XX_TIMER_TCR_CRST BIT(1) +#define LPC32XX_TIMER_TC 0x008 +#define LPC32XX_TIMER_PR 0x00c +#define LPC32XX_TIMER_MCR 0x014 +#define LPC32XX_TIMER_MCR_MR0I BIT(0) +#define LPC32XX_TIMER_MCR_MR0R BIT(1) +#define LPC32XX_TIMER_MCR_MR0S BIT(2) +#define LPC32XX_TIMER_MR0 0x018 +#define LPC32XX_TIMER_CTCR 0x070 + +struct lpc32xx_clock_event_ddata { + struct clock_event_device evtdev; + void __iomem *base; + u32 ticks_per_jiffy; +}; + +/* Needed for the sched clock */ +static void __iomem *clocksource_timer_counter; + +static u64 notrace lpc32xx_read_sched_clock(void) +{ + return readl(clocksource_timer_counter); +} + +static unsigned long lpc32xx_delay_timer_read(void) +{ + return readl(clocksource_timer_counter); +} + +static struct delay_timer lpc32xx_delay_timer = { + .read_current_timer = lpc32xx_delay_timer_read, +}; + +static int lpc32xx_clkevt_next_event(unsigned long delta, + struct clock_event_device *evtdev) +{ + struct lpc32xx_clock_event_ddata *ddata = + container_of(evtdev, struct lpc32xx_clock_event_ddata, evtdev); + + /* + * Place timer in reset and program the delta in the match + * channel 0 (MR0). When the timer counter matches the value + * in MR0 register the match will trigger an interrupt. + * After setup the timer is released from reset and enabled. + */ + writel_relaxed(LPC32XX_TIMER_TCR_CRST, ddata->base + LPC32XX_TIMER_TCR); + writel_relaxed(delta, ddata->base + LPC32XX_TIMER_MR0); + writel_relaxed(LPC32XX_TIMER_TCR_CEN, ddata->base + LPC32XX_TIMER_TCR); + + return 0; +} + +static int lpc32xx_clkevt_shutdown(struct clock_event_device *evtdev) +{ + struct lpc32xx_clock_event_ddata *ddata = + container_of(evtdev, struct lpc32xx_clock_event_ddata, evtdev); + + /* Disable the timer */ + writel_relaxed(0, ddata->base + LPC32XX_TIMER_TCR); + + return 0; +} + +static int lpc32xx_clkevt_oneshot(struct clock_event_device *evtdev) +{ + struct lpc32xx_clock_event_ddata *ddata = + container_of(evtdev, struct lpc32xx_clock_event_ddata, evtdev); + + /* + * When using oneshot, we must also disable the timer + * to wait for the first call to set_next_event(). + */ + writel_relaxed(0, ddata->base + LPC32XX_TIMER_TCR); + + /* Enable interrupt, reset on match and stop on match (MCR). */ + writel_relaxed(LPC32XX_TIMER_MCR_MR0I | LPC32XX_TIMER_MCR_MR0R | + LPC32XX_TIMER_MCR_MR0S, ddata->base + LPC32XX_TIMER_MCR); + return 0; +} + +static int lpc32xx_clkevt_periodic(struct clock_event_device *evtdev) +{ + struct lpc32xx_clock_event_ddata *ddata = + container_of(evtdev, struct lpc32xx_clock_event_ddata, evtdev); + + /* Enable interrupt and reset on match. */ + writel_relaxed(LPC32XX_TIMER_MCR_MR0I | LPC32XX_TIMER_MCR_MR0R, + ddata->base + LPC32XX_TIMER_MCR); + + /* + * Place timer in reset and program the delta in the match + * channel 0 (MR0). + */ + writel_relaxed(LPC32XX_TIMER_TCR_CRST, ddata->base + LPC32XX_TIMER_TCR); + writel_relaxed(ddata->ticks_per_jiffy, ddata->base + LPC32XX_TIMER_MR0); + writel_relaxed(LPC32XX_TIMER_TCR_CEN, ddata->base + LPC32XX_TIMER_TCR); + + return 0; +} + +static irqreturn_t lpc32xx_clock_event_handler(int irq, void *dev_id) +{ + struct lpc32xx_clock_event_ddata *ddata = dev_id; + + /* Clear match on channel 0 */ + writel_relaxed(LPC32XX_TIMER_IR_MR0INT, ddata->base + LPC32XX_TIMER_IR); + + ddata->evtdev.event_handler(&ddata->evtdev); + + return IRQ_HANDLED; +} + +static struct lpc32xx_clock_event_ddata lpc32xx_clk_event_ddata = { + .evtdev = { + .name = "lpc3220 clockevent", + .features = CLOCK_EVT_FEAT_ONESHOT | + CLOCK_EVT_FEAT_PERIODIC, + .rating = 300, + .set_next_event = lpc32xx_clkevt_next_event, + .set_state_shutdown = lpc32xx_clkevt_shutdown, + .set_state_oneshot = lpc32xx_clkevt_oneshot, + .set_state_periodic = lpc32xx_clkevt_periodic, + }, +}; + +static int __init lpc32xx_clocksource_init(struct device_node *np) +{ + void __iomem *base; + unsigned long rate; + struct clk *clk; + int ret; + + clk = of_clk_get_by_name(np, "timerclk"); + if (IS_ERR(clk)) { + pr_err("clock get failed (%ld)\n", PTR_ERR(clk)); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) { + pr_err("clock enable failed (%d)\n", ret); + goto err_clk_enable; + } + + base = of_iomap(np, 0); + if (!base) { + pr_err("unable to map registers\n"); + ret = -EADDRNOTAVAIL; + goto err_iomap; + } + + /* + * Disable and reset timer then set it to free running timer + * mode (CTCR) with no prescaler (PR) or match operations (MCR). + * After setup the timer is released from reset and enabled. + */ + writel_relaxed(LPC32XX_TIMER_TCR_CRST, base + LPC32XX_TIMER_TCR); + writel_relaxed(0, base + LPC32XX_TIMER_PR); + writel_relaxed(0, base + LPC32XX_TIMER_MCR); + writel_relaxed(0, base + LPC32XX_TIMER_CTCR); + writel_relaxed(LPC32XX_TIMER_TCR_CEN, base + LPC32XX_TIMER_TCR); + + rate = clk_get_rate(clk); + ret = clocksource_mmio_init(base + LPC32XX_TIMER_TC, "lpc3220 timer", + rate, 300, 32, clocksource_mmio_readl_up); + if (ret) { + pr_err("failed to init clocksource (%d)\n", ret); + goto err_clocksource_init; + } + + clocksource_timer_counter = base + LPC32XX_TIMER_TC; + lpc32xx_delay_timer.freq = rate; + register_current_timer_delay(&lpc32xx_delay_timer); + sched_clock_register(lpc32xx_read_sched_clock, 32, rate); + + return 0; + +err_clocksource_init: + iounmap(base); +err_iomap: + clk_disable_unprepare(clk); +err_clk_enable: + clk_put(clk); + return ret; +} + +static int __init lpc32xx_clockevent_init(struct device_node *np) +{ + void __iomem *base; + unsigned long rate; + struct clk *clk; + int ret, irq; + + clk = of_clk_get_by_name(np, "timerclk"); + if (IS_ERR(clk)) { + pr_err("clock get failed (%ld)\n", PTR_ERR(clk)); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) { + pr_err("clock enable failed (%d)\n", ret); + goto err_clk_enable; + } + + base = of_iomap(np, 0); + if (!base) { + pr_err("unable to map registers\n"); + ret = -EADDRNOTAVAIL; + goto err_iomap; + } + + irq = irq_of_parse_and_map(np, 0); + if (!irq) { + pr_err("get irq failed\n"); + ret = -ENOENT; + goto err_irq; + } + + /* + * Disable timer and clear any pending interrupt (IR) on match + * channel 0 (MR0). Clear the prescaler as it's not used. + */ + writel_relaxed(0, base + LPC32XX_TIMER_TCR); + writel_relaxed(0, base + LPC32XX_TIMER_PR); + writel_relaxed(0, base + LPC32XX_TIMER_CTCR); + writel_relaxed(LPC32XX_TIMER_IR_MR0INT, base + LPC32XX_TIMER_IR); + + rate = clk_get_rate(clk); + lpc32xx_clk_event_ddata.base = base; + lpc32xx_clk_event_ddata.ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ); + clockevents_config_and_register(&lpc32xx_clk_event_ddata.evtdev, + rate, 1, -1); + + ret = request_irq(irq, lpc32xx_clock_event_handler, + IRQF_TIMER | IRQF_IRQPOLL, "lpc3220 clockevent", + &lpc32xx_clk_event_ddata); + if (ret) { + pr_err("request irq failed\n"); + goto err_irq; + } + + return 0; + +err_irq: + iounmap(base); +err_iomap: + clk_disable_unprepare(clk); +err_clk_enable: + clk_put(clk); + return ret; +} + +/* + * This function asserts that we have exactly one clocksource and one + * clock_event_device in the end. + */ +static int __init lpc32xx_timer_init(struct device_node *np) +{ + static int has_clocksource, has_clockevent; + int ret = 0; + + if (!has_clocksource) { + ret = lpc32xx_clocksource_init(np); + if (!ret) { + has_clocksource = 1; + return 0; + } + } + + if (!has_clockevent) { + ret = lpc32xx_clockevent_init(np); + if (!ret) { + has_clockevent = 1; + return 0; + } + } + + return ret; +} +TIMER_OF_DECLARE(lpc32xx_timer, "nxp,lpc3220-timer", lpc32xx_timer_init); -- cgit v1.3.1