From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/rtc/rtc-ftrtc010.c | 218 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 218 insertions(+) create mode 100644 drivers/rtc/rtc-ftrtc010.c (limited to 'drivers/rtc/rtc-ftrtc010.c') diff --git a/drivers/rtc/rtc-ftrtc010.c b/drivers/rtc/rtc-ftrtc010.c new file mode 100644 index 000000000..98fa0f518 --- /dev/null +++ b/drivers/rtc/rtc-ftrtc010.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Faraday Technology FTRTC010 driver + * + * Copyright (C) 2009 Janos Laube + * + * Original code for older kernel 2.6.15 are from Stormlinksemi + * first update from Janos Laube for > 2.6.29 kernels + * + * checkpatch fixes and usage of rtc-lib code + * Hans Ulli Kroll + */ + +#include +#include +#include +#include +#include +#include +#include + +#define DRV_NAME "rtc-ftrtc010" + +MODULE_AUTHOR("Hans Ulli Kroll "); +MODULE_DESCRIPTION("RTC driver for Gemini SoC"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME); + +struct ftrtc010_rtc { + void __iomem *rtc_base; + int rtc_irq; + struct clk *pclk; + struct clk *extclk; +}; + +enum ftrtc010_rtc_offsets { + FTRTC010_RTC_SECOND = 0x00, + FTRTC010_RTC_MINUTE = 0x04, + FTRTC010_RTC_HOUR = 0x08, + FTRTC010_RTC_DAYS = 0x0C, + FTRTC010_RTC_ALARM_SECOND = 0x10, + FTRTC010_RTC_ALARM_MINUTE = 0x14, + FTRTC010_RTC_ALARM_HOUR = 0x18, + FTRTC010_RTC_RECORD = 0x1C, + FTRTC010_RTC_CR = 0x20, +}; + +static irqreturn_t ftrtc010_rtc_interrupt(int irq, void *dev) +{ + return IRQ_HANDLED; +} + +/* + * Looks like the RTC in the Gemini SoC is (totaly) broken + * We can't read/write directly the time from RTC registers. + * We must do some "offset" calculation to get the real time + * + * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does + * the same thing, without the rtc-lib.c calls. + */ + +static int ftrtc010_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct ftrtc010_rtc *rtc = dev_get_drvdata(dev); + + u32 days, hour, min, sec, offset; + timeu64_t time; + + sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND); + min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE); + hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR); + days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS); + offset = readl(rtc->rtc_base + FTRTC010_RTC_RECORD); + + time = offset + days * 86400 + hour * 3600 + min * 60 + sec; + + rtc_time64_to_tm(time, tm); + + return 0; +} + +static int ftrtc010_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct ftrtc010_rtc *rtc = dev_get_drvdata(dev); + u32 sec, min, hour, day, offset; + timeu64_t time; + + time = rtc_tm_to_time64(tm); + + sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND); + min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE); + hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR); + day = readl(rtc->rtc_base + FTRTC010_RTC_DAYS); + + offset = time - (day * 86400 + hour * 3600 + min * 60 + sec); + + writel(offset, rtc->rtc_base + FTRTC010_RTC_RECORD); + writel(0x01, rtc->rtc_base + FTRTC010_RTC_CR); + + return 0; +} + +static const struct rtc_class_ops ftrtc010_rtc_ops = { + .read_time = ftrtc010_rtc_read_time, + .set_time = ftrtc010_rtc_set_time, +}; + +static int ftrtc010_rtc_probe(struct platform_device *pdev) +{ + u32 days, hour, min, sec; + struct ftrtc010_rtc *rtc; + struct device *dev = &pdev->dev; + struct resource *res; + struct rtc_device *rtc_dev; + int ret; + + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); + if (unlikely(!rtc)) + return -ENOMEM; + platform_set_drvdata(pdev, rtc); + + rtc->pclk = devm_clk_get(dev, "PCLK"); + if (IS_ERR(rtc->pclk)) { + dev_err(dev, "could not get PCLK\n"); + } else { + ret = clk_prepare_enable(rtc->pclk); + if (ret) { + dev_err(dev, "failed to enable PCLK\n"); + return ret; + } + } + rtc->extclk = devm_clk_get(dev, "EXTCLK"); + if (IS_ERR(rtc->extclk)) { + dev_err(dev, "could not get EXTCLK\n"); + } else { + ret = clk_prepare_enable(rtc->extclk); + if (ret) { + dev_err(dev, "failed to enable EXTCLK\n"); + goto err_disable_pclk; + } + } + + rtc->rtc_irq = platform_get_irq(pdev, 0); + if (rtc->rtc_irq < 0) { + ret = rtc->rtc_irq; + goto err_disable_extclk; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + ret = -ENODEV; + goto err_disable_extclk; + } + + rtc->rtc_base = devm_ioremap(dev, res->start, + resource_size(res)); + if (!rtc->rtc_base) { + ret = -ENOMEM; + goto err_disable_extclk; + } + + rtc_dev = devm_rtc_allocate_device(dev); + if (IS_ERR(rtc_dev)) { + ret = PTR_ERR(rtc_dev); + goto err_disable_extclk; + } + + rtc_dev->ops = &ftrtc010_rtc_ops; + + sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND); + min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE); + hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR); + days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS); + + rtc_dev->range_min = (u64)days * 86400 + hour * 3600 + min * 60 + sec; + rtc_dev->range_max = U32_MAX + rtc_dev->range_min; + + ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt, + IRQF_SHARED, pdev->name, dev); + if (unlikely(ret)) + goto err_disable_extclk; + + return devm_rtc_register_device(rtc_dev); + +err_disable_extclk: + clk_disable_unprepare(rtc->extclk); +err_disable_pclk: + clk_disable_unprepare(rtc->pclk); + return ret; +} + +static void ftrtc010_rtc_remove(struct platform_device *pdev) +{ + struct ftrtc010_rtc *rtc = platform_get_drvdata(pdev); + + if (!IS_ERR(rtc->extclk)) + clk_disable_unprepare(rtc->extclk); + if (!IS_ERR(rtc->pclk)) + clk_disable_unprepare(rtc->pclk); +} + +static const struct of_device_id ftrtc010_rtc_dt_match[] = { + { .compatible = "cortina,gemini-rtc" }, + { .compatible = "faraday,ftrtc010" }, + { } +}; +MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match); + +static struct platform_driver ftrtc010_rtc_driver = { + .driver = { + .name = DRV_NAME, + .of_match_table = ftrtc010_rtc_dt_match, + }, + .probe = ftrtc010_rtc_probe, + .remove = ftrtc010_rtc_remove, +}; + +module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe); -- cgit v1.3.1