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-fsl-ftm.c | 355 ++++++++++++++++++++++++++++++++++++ 1 file changed, 355 insertions(+) create mode 100644 drivers/clocksource/timer-fsl-ftm.c (limited to 'drivers/clocksource/timer-fsl-ftm.c') diff --git a/drivers/clocksource/timer-fsl-ftm.c b/drivers/clocksource/timer-fsl-ftm.c new file mode 100644 index 000000000..4eed6cb46 --- /dev/null +++ b/drivers/clocksource/timer-fsl-ftm.c @@ -0,0 +1,355 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Freescale FlexTimer Module (FTM) timer driver. + * + * Copyright 2014 Freescale Semiconductor, Inc. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define FTM_SC_CLK(c) ((c) << FTM_SC_CLK_MASK_SHIFT) + +struct ftm_clock_device { + void __iomem *clksrc_base; + void __iomem *clkevt_base; + unsigned long periodic_cyc; + unsigned long ps; + bool big_endian; +}; + +static struct ftm_clock_device *priv; + +static inline u32 ftm_readl(void __iomem *addr) +{ + if (priv->big_endian) + return ioread32be(addr); + else + return ioread32(addr); +} + +static inline void ftm_writel(u32 val, void __iomem *addr) +{ + if (priv->big_endian) + iowrite32be(val, addr); + else + iowrite32(val, addr); +} + +static inline void ftm_counter_enable(void __iomem *base) +{ + u32 val; + + /* select and enable counter clock source */ + val = ftm_readl(base + FTM_SC); + val &= ~(FTM_SC_PS_MASK | FTM_SC_CLK_MASK); + val |= priv->ps | FTM_SC_CLK(1); + ftm_writel(val, base + FTM_SC); +} + +static inline void ftm_counter_disable(void __iomem *base) +{ + u32 val; + + /* disable counter clock source */ + val = ftm_readl(base + FTM_SC); + val &= ~(FTM_SC_PS_MASK | FTM_SC_CLK_MASK); + ftm_writel(val, base + FTM_SC); +} + +static inline void ftm_irq_acknowledge(void __iomem *base) +{ + u32 val; + + val = ftm_readl(base + FTM_SC); + val &= ~FTM_SC_TOF; + ftm_writel(val, base + FTM_SC); +} + +static inline void ftm_irq_enable(void __iomem *base) +{ + u32 val; + + val = ftm_readl(base + FTM_SC); + val |= FTM_SC_TOIE; + ftm_writel(val, base + FTM_SC); +} + +static inline void ftm_irq_disable(void __iomem *base) +{ + u32 val; + + val = ftm_readl(base + FTM_SC); + val &= ~FTM_SC_TOIE; + ftm_writel(val, base + FTM_SC); +} + +static inline void ftm_reset_counter(void __iomem *base) +{ + /* + * The CNT register contains the FTM counter value. + * Reset clears the CNT register. Writing any value to COUNT + * updates the counter with its initial value, CNTIN. + */ + ftm_writel(0x00, base + FTM_CNT); +} + +static u64 notrace ftm_read_sched_clock(void) +{ + return ftm_readl(priv->clksrc_base + FTM_CNT); +} + +static int ftm_set_next_event(unsigned long delta, + struct clock_event_device *unused) +{ + /* + * The CNNIN and MOD are all double buffer registers, writing + * to the MOD register latches the value into a buffer. The MOD + * register is updated with the value of its write buffer with + * the following scenario: + * a, the counter source clock is disabled. + */ + ftm_counter_disable(priv->clkevt_base); + + /* Force the value of CNTIN to be loaded into the FTM counter */ + ftm_reset_counter(priv->clkevt_base); + + /* + * The counter increments until the value of MOD is reached, + * at which point the counter is reloaded with the value of CNTIN. + * The TOF (the overflow flag) bit is set when the FTM counter + * changes from MOD to CNTIN. So we should using the delta - 1. + */ + ftm_writel(delta - 1, priv->clkevt_base + FTM_MOD); + + ftm_counter_enable(priv->clkevt_base); + + ftm_irq_enable(priv->clkevt_base); + + return 0; +} + +static int ftm_set_oneshot(struct clock_event_device *evt) +{ + ftm_counter_disable(priv->clkevt_base); + return 0; +} + +static int ftm_set_periodic(struct clock_event_device *evt) +{ + ftm_set_next_event(priv->periodic_cyc, evt); + return 0; +} + +static irqreturn_t ftm_evt_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + ftm_irq_acknowledge(priv->clkevt_base); + + if (likely(clockevent_state_oneshot(evt))) { + ftm_irq_disable(priv->clkevt_base); + ftm_counter_disable(priv->clkevt_base); + } + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct clock_event_device ftm_clockevent = { + .name = "Freescale ftm timer", + .features = CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT, + .set_state_periodic = ftm_set_periodic, + .set_state_oneshot = ftm_set_oneshot, + .set_next_event = ftm_set_next_event, + .rating = 300, +}; + +static int __init ftm_clockevent_init(unsigned long freq, int irq) +{ + int err; + + ftm_writel(0x00, priv->clkevt_base + FTM_CNTIN); + ftm_writel(~0u, priv->clkevt_base + FTM_MOD); + + ftm_reset_counter(priv->clkevt_base); + + err = request_irq(irq, ftm_evt_interrupt, IRQF_TIMER | IRQF_IRQPOLL, + "Freescale ftm timer", &ftm_clockevent); + if (err) { + pr_err("ftm: setup irq failed: %d\n", err); + return err; + } + + ftm_clockevent.cpumask = cpumask_of(0); + ftm_clockevent.irq = irq; + + clockevents_config_and_register(&ftm_clockevent, + freq / (1 << priv->ps), + 1, 0xffff); + + ftm_counter_enable(priv->clkevt_base); + + return 0; +} + +static int __init ftm_clocksource_init(unsigned long freq) +{ + int err; + + ftm_writel(0x00, priv->clksrc_base + FTM_CNTIN); + ftm_writel(~0u, priv->clksrc_base + FTM_MOD); + + ftm_reset_counter(priv->clksrc_base); + + sched_clock_register(ftm_read_sched_clock, 16, freq / (1 << priv->ps)); + err = clocksource_mmio_init(priv->clksrc_base + FTM_CNT, "fsl-ftm", + freq / (1 << priv->ps), 300, 16, + clocksource_mmio_readl_up); + if (err) { + pr_err("ftm: init clock source mmio failed: %d\n", err); + return err; + } + + ftm_counter_enable(priv->clksrc_base); + + return 0; +} + +static int __init __ftm_clk_init(struct device_node *np, char *cnt_name, + char *ftm_name) +{ + struct clk *clk; + int err; + + clk = of_clk_get_by_name(np, cnt_name); + if (IS_ERR(clk)) { + pr_err("ftm: Cannot get \"%s\": %ld\n", cnt_name, PTR_ERR(clk)); + return PTR_ERR(clk); + } + err = clk_prepare_enable(clk); + if (err) { + pr_err("ftm: clock failed to prepare+enable \"%s\": %d\n", + cnt_name, err); + return err; + } + + clk = of_clk_get_by_name(np, ftm_name); + if (IS_ERR(clk)) { + pr_err("ftm: Cannot get \"%s\": %ld\n", ftm_name, PTR_ERR(clk)); + return PTR_ERR(clk); + } + err = clk_prepare_enable(clk); + if (err) + pr_err("ftm: clock failed to prepare+enable \"%s\": %d\n", + ftm_name, err); + + return clk_get_rate(clk); +} + +static unsigned long __init ftm_clk_init(struct device_node *np) +{ + long freq; + + freq = __ftm_clk_init(np, "ftm-evt-counter-en", "ftm-evt"); + if (freq <= 0) + return 0; + + freq = __ftm_clk_init(np, "ftm-src-counter-en", "ftm-src"); + if (freq <= 0) + return 0; + + return freq; +} + +static int __init ftm_calc_closest_round_cyc(unsigned long freq) +{ + priv->ps = 0; + + /* The counter register is only using the lower 16 bits, and + * if the 'freq' value is to big here, then the periodic_cyc + * may exceed 0xFFFF. + */ + do { + priv->periodic_cyc = DIV_ROUND_CLOSEST(freq, + HZ * (1 << priv->ps++)); + } while (priv->periodic_cyc > 0xFFFF); + + if (priv->ps > FTM_PS_MAX) { + pr_err("ftm: the prescaler is %lu > %d\n", + priv->ps, FTM_PS_MAX); + return -EINVAL; + } + + return 0; +} + +static int __init ftm_timer_init(struct device_node *np) +{ + unsigned long freq; + int ret, irq; + + priv = kzalloc_obj(*priv); + if (!priv) + return -ENOMEM; + + ret = -ENXIO; + priv->clkevt_base = of_iomap(np, 0); + if (!priv->clkevt_base) { + pr_err("ftm: unable to map event timer registers\n"); + goto err_clkevt; + } + + priv->clksrc_base = of_iomap(np, 1); + if (!priv->clksrc_base) { + pr_err("ftm: unable to map source timer registers\n"); + goto err_clksrc; + } + + ret = -EINVAL; + irq = irq_of_parse_and_map(np, 0); + if (irq <= 0) { + pr_err("ftm: unable to get IRQ from DT, %d\n", irq); + goto err; + } + + priv->big_endian = of_property_read_bool(np, "big-endian"); + + freq = ftm_clk_init(np); + if (!freq) + goto err; + + ret = ftm_calc_closest_round_cyc(freq); + if (ret) + goto err; + + ret = ftm_clocksource_init(freq); + if (ret) + goto err; + + ret = ftm_clockevent_init(freq, irq); + if (ret) + goto err; + + return 0; + +err: + iounmap(priv->clksrc_base); +err_clksrc: + iounmap(priv->clkevt_base); +err_clkevt: + kfree(priv); + return ret; +} +TIMER_OF_DECLARE(flextimer, "fsl,ftm-timer", ftm_timer_init); -- cgit v1.3.1