From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 22 Sep 2026 19:14:30 +0100 Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits. Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba Reviewed-by: Anshuman Khandual Reviewed-by: Oliver Upton Signed-off-by: Will Deacon --- drivers/rtc/rtc-88pm886.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 drivers/rtc/rtc-88pm886.c (limited to 'drivers/rtc/rtc-88pm886.c') diff --git a/drivers/rtc/rtc-88pm886.c b/drivers/rtc/rtc-88pm886.c new file mode 100644 index 000000000..71443ae1b --- /dev/null +++ b/drivers/rtc/rtc-88pm886.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include + +#include + +/* + * Time is calculated as the sum of a 32-bit read-only advancing counter and a + * writeable constant offset stored in the chip's spare registers. + */ + +static int pm886_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct regmap *regmap = dev_get_drvdata(dev); + u32 time; + u32 buf; + int ret; + + ret = regmap_bulk_read(regmap, PM886_REG_RTC_SPARE1, &buf, 4); + if (ret) + return ret; + time = buf; + + ret = regmap_bulk_read(regmap, PM886_REG_RTC_CNT1, &buf, 4); + if (ret) + return ret; + time += buf; + + rtc_time64_to_tm(time, tm); + + return 0; +} + +static int pm886_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct regmap *regmap = dev_get_drvdata(dev); + u32 buf; + int ret; + + ret = regmap_bulk_read(regmap, PM886_REG_RTC_CNT1, &buf, 4); + if (ret) + return ret; + + buf = rtc_tm_to_time64(tm) - buf; + + return regmap_bulk_write(regmap, PM886_REG_RTC_SPARE1, &buf, 4); +} + +static const struct rtc_class_ops pm886_rtc_ops = { + .read_time = pm886_rtc_read_time, + .set_time = pm886_rtc_set_time, +}; + +static int pm886_rtc_probe(struct platform_device *pdev) +{ + struct pm886_chip *chip = dev_get_drvdata(pdev->dev.parent); + struct device *dev = &pdev->dev; + struct rtc_device *rtc; + int ret; + + platform_set_drvdata(pdev, chip->regmap); + + rtc = devm_rtc_allocate_device(dev); + if (IS_ERR(rtc)) + return dev_err_probe(dev, PTR_ERR(rtc), + "Failed to allocate RTC device\n"); + + rtc->ops = &pm886_rtc_ops; + rtc->range_max = U32_MAX; + + ret = devm_rtc_register_device(rtc); + if (ret) + return dev_err_probe(dev, ret, "Failed to register RTC device\n"); + + return 0; +} + +static const struct platform_device_id pm886_rtc_id_table[] = { + { .name = "88pm886-rtc" }, + { } +}; +MODULE_DEVICE_TABLE(platform, pm886_rtc_id_table); + +static struct platform_driver pm886_rtc_driver = { + .driver = { + .name = "88pm886-rtc", + }, + .probe = pm886_rtc_probe, + .id_table = pm886_rtc_id_table, +}; +module_platform_driver(pm886_rtc_driver); + +MODULE_DESCRIPTION("Marvell 88PM886 RTC driver"); +MODULE_AUTHOR("Karel Balej "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1