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/rtc/rtc-sh.c | 506 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 506 insertions(+) create mode 100644 drivers/rtc/rtc-sh.c (limited to 'drivers/rtc/rtc-sh.c') diff --git a/drivers/rtc/rtc-sh.c b/drivers/rtc/rtc-sh.c new file mode 100644 index 000000000..7a5feceb9 --- /dev/null +++ b/drivers/rtc/rtc-sh.c @@ -0,0 +1,506 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SuperH On-Chip RTC Support + * + * Copyright (C) 2006 - 2009 Paul Mundt + * Copyright (C) 2006 Jamie Lenehan + * Copyright (C) 2008 Angelo Castello + * Copyright (C) 2025 Wolfram Sang, Renesas Electronics Corporation + * + * Based on the old arch/sh/kernel/cpu/rtc.c by: + * + * Copyright (C) 2000 Philipp Rumpf + * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_SUPERH +#include +#else +/* Default values for RZ/A RTC */ +#define rtc_reg_size sizeof(u16) +#define RTC_BIT_INVERTED 0 /* no chip bugs */ +#define RTC_CAP_4_DIGIT_YEAR BIT(0) +#define RTC_DEF_CAPABILITIES RTC_CAP_4_DIGIT_YEAR +#endif + +#define DRV_NAME "sh-rtc" + +#define RTC_REG(r) ((r) * rtc_reg_size) + +#define R64CNT RTC_REG(0) + +#define RSECCNT RTC_REG(1) /* RTC sec */ +#define RMINCNT RTC_REG(2) /* RTC min */ +#define RHRCNT RTC_REG(3) /* RTC hour */ +#define RWKCNT RTC_REG(4) /* RTC week */ +#define RDAYCNT RTC_REG(5) /* RTC day */ +#define RMONCNT RTC_REG(6) /* RTC month */ +#define RYRCNT RTC_REG(7) /* RTC year */ +#define RSECAR RTC_REG(8) /* ALARM sec */ +#define RMINAR RTC_REG(9) /* ALARM min */ +#define RHRAR RTC_REG(10) /* ALARM hour */ +#define RWKAR RTC_REG(11) /* ALARM week */ +#define RDAYAR RTC_REG(12) /* ALARM day */ +#define RMONAR RTC_REG(13) /* ALARM month */ +#define RCR1 RTC_REG(14) /* Control */ +#define RCR2 RTC_REG(15) /* Control */ + +/* + * Note on RYRAR and RCR3: Up until this point most of the register + * definitions are consistent across all of the available parts. However, + * the placement of the optional RYRAR and RCR3 (the RYRAR control + * register used to control RYRCNT/RYRAR compare) varies considerably + * across various parts, occasionally being mapped in to a completely + * unrelated address space. For proper RYRAR support a separate resource + * would have to be handed off, but as this is purely optional in + * practice, we simply opt not to support it, thereby keeping the code + * quite a bit more simplified. + */ + +/* ALARM Bits - or with BCD encoded value */ +#define AR_ENB BIT(7) /* Enable for alarm cmp */ + +/* RCR1 Bits */ +#define RCR1_CF BIT(7) /* Carry Flag */ +#define RCR1_CIE BIT(4) /* Carry Interrupt Enable */ +#define RCR1_AIE BIT(3) /* Alarm Interrupt Enable */ +#define RCR1_AF BIT(0) /* Alarm Flag */ + +/* RCR2 Bits */ +#define RCR2_RTCEN BIT(3) /* ENable RTC */ +#define RCR2_ADJ BIT(2) /* ADJustment (30-second) */ +#define RCR2_RESET BIT(1) /* Reset bit */ +#define RCR2_START BIT(0) /* Start bit */ + +struct sh_rtc { + void __iomem *regbase; + int alarm_irq; + struct clk *clk; + struct rtc_device *rtc_dev; + spinlock_t lock; /* protecting register access */ + unsigned long capabilities; /* See asm/rtc.h for cap bits */ +}; + +static irqreturn_t sh_rtc_alarm(int irq, void *dev_id) +{ + struct sh_rtc *rtc = dev_id; + unsigned int tmp, pending; + + spin_lock(&rtc->lock); + + tmp = readb(rtc->regbase + RCR1); + pending = tmp & RCR1_AF; + tmp &= ~(RCR1_AF | RCR1_AIE); + writeb(tmp, rtc->regbase + RCR1); + + if (pending) + rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF); + + spin_unlock(&rtc->lock); + + return IRQ_RETVAL(pending); +} + +static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int tmp; + + spin_lock_irq(&rtc->lock); + + tmp = readb(rtc->regbase + RCR1); + + if (enable) + tmp |= RCR1_AIE; + else + tmp &= ~RCR1_AIE; + + writeb(tmp, rtc->regbase + RCR1); + + spin_unlock_irq(&rtc->lock); + + return 0; +} + +static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int sec128, sec2, yr, yr100, cf_bit; + + if (!(readb(rtc->regbase + RCR2) & RCR2_RTCEN)) + return -EINVAL; + + do { + unsigned int tmp; + + spin_lock_irq(&rtc->lock); + + tmp = readb(rtc->regbase + RCR1); + tmp &= ~RCR1_CF; /* Clear CF-bit */ + tmp |= RCR1_CIE; + writeb(tmp, rtc->regbase + RCR1); + + sec128 = readb(rtc->regbase + R64CNT); + + tm->tm_sec = bcd2bin(readb(rtc->regbase + RSECCNT)); + tm->tm_min = bcd2bin(readb(rtc->regbase + RMINCNT)); + tm->tm_hour = bcd2bin(readb(rtc->regbase + RHRCNT)); + tm->tm_wday = bcd2bin(readb(rtc->regbase + RWKCNT)); + tm->tm_mday = bcd2bin(readb(rtc->regbase + RDAYCNT)); + tm->tm_mon = bcd2bin(readb(rtc->regbase + RMONCNT)) - 1; + + if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) { + yr = readw(rtc->regbase + RYRCNT); + yr100 = bcd2bin(yr >> 8); + yr &= 0xff; + } else { + yr = readb(rtc->regbase + RYRCNT); + yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20); + } + + tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900; + + sec2 = readb(rtc->regbase + R64CNT); + cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF; + + spin_unlock_irq(&rtc->lock); + } while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0); + +#if RTC_BIT_INVERTED != 0 + if ((sec128 & RTC_BIT_INVERTED)) + tm->tm_sec--; +#endif + + dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", + __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, + tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday); + + return 0; +} + +static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int tmp; + int year; + + spin_lock_irq(&rtc->lock); + + /* Reset pre-scaler & stop RTC */ + tmp = readb(rtc->regbase + RCR2); + tmp |= RCR2_RESET; + tmp &= ~RCR2_START; + writeb(tmp, rtc->regbase + RCR2); + + writeb(bin2bcd(tm->tm_sec), rtc->regbase + RSECCNT); + writeb(bin2bcd(tm->tm_min), rtc->regbase + RMINCNT); + writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT); + writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT); + writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT); + writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT); + + if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) { + year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) | + bin2bcd(tm->tm_year % 100); + writew(year, rtc->regbase + RYRCNT); + } else { + year = tm->tm_year % 100; + writeb(bin2bcd(year), rtc->regbase + RYRCNT); + } + + /* Start RTC */ + tmp = readb(rtc->regbase + RCR2); + tmp &= ~RCR2_RESET; + tmp |= RCR2_RTCEN | RCR2_START; + writeb(tmp, rtc->regbase + RCR2); + + spin_unlock_irq(&rtc->lock); + + return 0; +} + +static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off) +{ + unsigned int byte; + int value = -1; /* return -1 for ignored values */ + + byte = readb(rtc->regbase + reg_off); + if (byte & AR_ENB) { + byte &= ~AR_ENB; /* strip the enable bit */ + value = bcd2bin(byte); + } + + return value; +} + +static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + struct rtc_time *tm = &wkalrm->time; + + spin_lock_irq(&rtc->lock); + + tm->tm_sec = sh_rtc_read_alarm_value(rtc, RSECAR); + tm->tm_min = sh_rtc_read_alarm_value(rtc, RMINAR); + tm->tm_hour = sh_rtc_read_alarm_value(rtc, RHRAR); + tm->tm_wday = sh_rtc_read_alarm_value(rtc, RWKAR); + tm->tm_mday = sh_rtc_read_alarm_value(rtc, RDAYAR); + tm->tm_mon = sh_rtc_read_alarm_value(rtc, RMONAR); + if (tm->tm_mon > 0) + tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */ + + wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0; + + spin_unlock_irq(&rtc->lock); + + return 0; +} + +static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc, + int value, int reg_off) +{ + /* < 0 for a value that is ignored */ + if (value < 0) + writeb(0, rtc->regbase + reg_off); + else + writeb(bin2bcd(value) | AR_ENB, rtc->regbase + reg_off); +} + +static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + unsigned int rcr1; + struct rtc_time *tm = &wkalrm->time; + int mon; + + spin_lock_irq(&rtc->lock); + + /* disable alarm interrupt and clear the alarm flag */ + rcr1 = readb(rtc->regbase + RCR1); + rcr1 &= ~(RCR1_AF | RCR1_AIE); + writeb(rcr1, rtc->regbase + RCR1); + + /* set alarm time */ + sh_rtc_write_alarm_value(rtc, tm->tm_sec, RSECAR); + sh_rtc_write_alarm_value(rtc, tm->tm_min, RMINAR); + sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR); + sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR); + sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR); + mon = tm->tm_mon; + if (mon >= 0) + mon += 1; + sh_rtc_write_alarm_value(rtc, mon, RMONAR); + + if (wkalrm->enabled) { + rcr1 |= RCR1_AIE; + writeb(rcr1, rtc->regbase + RCR1); + } + + spin_unlock_irq(&rtc->lock); + + return 0; +} + +static const struct rtc_class_ops sh_rtc_ops = { + .read_time = sh_rtc_read_time, + .set_time = sh_rtc_set_time, + .read_alarm = sh_rtc_read_alarm, + .set_alarm = sh_rtc_set_alarm, + .alarm_irq_enable = sh_rtc_alarm_irq_enable, +}; + +static int __init sh_rtc_probe(struct platform_device *pdev) +{ + struct sh_rtc *rtc; + struct resource *res, *req_res; + char clk_name[14]; + int clk_id, ret; + unsigned int tmp; + resource_size_t regsize; + + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); + if (unlikely(!rtc)) + return -ENOMEM; + + spin_lock_init(&rtc->lock); + + ret = platform_get_irq(pdev, 0); + if (unlikely(ret <= 0)) { + dev_err(&pdev->dev, "No IRQ resource\n"); + return -ENOENT; + } + + if (!pdev->dev.of_node) + rtc->alarm_irq = platform_get_irq(pdev, 2); + else + rtc->alarm_irq = ret; + + res = platform_get_resource(pdev, IORESOURCE_IO, 0); + if (!res) + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "No IO resource\n"); + return -ENOENT; + } + + regsize = resource_size(res); + req_res = devm_request_mem_region(&pdev->dev, res->start, regsize, pdev->name); + if (!req_res) + return -EBUSY; + + rtc->regbase = devm_ioremap(&pdev->dev, req_res->start, regsize); + if (!rtc->regbase) + return -EINVAL; + + if (!pdev->dev.of_node) { + clk_id = pdev->id; + /* With a single device, the clock id is still "rtc0" */ + if (clk_id < 0) + clk_id = 0; + + snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id); + } else { + snprintf(clk_name, sizeof(clk_name), "fck"); + } + + rtc->clk = devm_clk_get(&pdev->dev, clk_name); + if (IS_ERR(rtc->clk)) { + /* + * No error handling for rtc->clk intentionally, not all + * platforms will have a unique clock for the RTC, and + * the clk API can handle the struct clk pointer being + * NULL. + */ + rtc->clk = NULL; + } + + rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc->rtc_dev)) + return PTR_ERR(rtc->rtc_dev); + + clk_enable(rtc->clk); + + rtc->capabilities = RTC_DEF_CAPABILITIES; + +#ifdef CONFIG_SUPERH + if (dev_get_platdata(&pdev->dev)) { + struct sh_rtc_platform_info *pinfo = + dev_get_platdata(&pdev->dev); + + /* + * Some CPUs have special capabilities in addition to the + * default set. Add those in here. + */ + rtc->capabilities |= pinfo->capabilities; + } +#endif + + ret = devm_request_irq(&pdev->dev, rtc->alarm_irq, sh_rtc_alarm, 0, "sh-rtc", rtc); + if (ret) { + dev_err(&pdev->dev, "request alarm IRQ failed with %d, IRQ %d\n", + ret, rtc->alarm_irq); + goto err_unmap; + } + + platform_set_drvdata(pdev, rtc); + + /* everything disabled by default */ + tmp = readb(rtc->regbase + RCR1); + tmp &= ~(RCR1_CIE | RCR1_AIE); + writeb(tmp, rtc->regbase + RCR1); + + rtc->rtc_dev->ops = &sh_rtc_ops; + + if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) { + rtc->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_1900; + rtc->rtc_dev->range_max = RTC_TIMESTAMP_END_9999; + } else { + rtc->rtc_dev->range_min = mktime64(1999, 1, 1, 0, 0, 0); + rtc->rtc_dev->range_max = mktime64(2098, 12, 31, 23, 59, 59); + } + + ret = devm_rtc_register_device(rtc->rtc_dev); + if (ret) + goto err_unmap; + + device_init_wakeup(&pdev->dev, true); + return 0; + +err_unmap: + clk_disable(rtc->clk); + + return ret; +} + +static void __exit sh_rtc_remove(struct platform_device *pdev) +{ + struct sh_rtc *rtc = platform_get_drvdata(pdev); + + sh_rtc_alarm_irq_enable(&pdev->dev, 0); + + clk_disable(rtc->clk); +} + +static int sh_rtc_suspend(struct device *dev) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + irq_set_irq_wake(rtc->alarm_irq, 1); + + return 0; +} + +static int sh_rtc_resume(struct device *dev) +{ + struct sh_rtc *rtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + irq_set_irq_wake(rtc->alarm_irq, 0); + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume); + +static const struct of_device_id sh_rtc_of_match[] = { + { .compatible = "renesas,sh-rtc", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sh_rtc_of_match); + +/* + * sh_rtc_remove() lives in .exit.text. For drivers registered via + * module_platform_driver_probe() this is ok because they cannot get unbound at + * runtime. So mark the driver struct with __refdata to prevent modpost + * triggering a section mismatch warning. + */ +static struct platform_driver sh_rtc_platform_driver __refdata = { + .driver = { + .name = DRV_NAME, + .pm = pm_sleep_ptr(&sh_rtc_pm_ops), + .of_match_table = sh_rtc_of_match, + }, + .remove = __exit_p(sh_rtc_remove), +}; + +module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe); + +MODULE_DESCRIPTION("SuperH on-chip RTC driver"); +MODULE_AUTHOR("Paul Mundt "); +MODULE_AUTHOR("Jamie Lenehan "); +MODULE_AUTHOR("Angelo Castello "); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRV_NAME); -- cgit v1.3.1