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-starfire.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 drivers/rtc/rtc-starfire.c (limited to 'drivers/rtc/rtc-starfire.c') diff --git a/drivers/rtc/rtc-starfire.c b/drivers/rtc/rtc-starfire.c new file mode 100644 index 000000000..fbd1ed41c --- /dev/null +++ b/drivers/rtc/rtc-starfire.c @@ -0,0 +1,60 @@ +/* rtc-starfire.c: Starfire platform RTC driver. + * + * Author: David S. Miller + * License: GPL + * + * Copyright (C) 2008 David S. Miller + */ + +#include +#include +#include +#include + +#include + +static u32 starfire_get_time(void) +{ + static char obp_gettod[32]; + static u32 unix_tod; + + sprintf(obp_gettod, "h# %08x unix-gettod", + (unsigned int) (long) &unix_tod); + prom_feval(obp_gettod); + + return unix_tod; +} + +static int starfire_read_time(struct device *dev, struct rtc_time *tm) +{ + rtc_time64_to_tm(starfire_get_time(), tm); + return 0; +} + +static const struct rtc_class_ops starfire_rtc_ops = { + .read_time = starfire_read_time, +}; + +static int __init starfire_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + + rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &starfire_rtc_ops; + rtc->range_max = U32_MAX; + + platform_set_drvdata(pdev, rtc); + + return devm_rtc_register_device(rtc); +} + +static struct platform_driver starfire_rtc_driver = { + .driver = { + .name = "rtc-starfire", + }, +}; + +builtin_platform_driver_probe(starfire_rtc_driver, starfire_rtc_probe); -- cgit v1.3.1