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/pps/kc.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 drivers/pps/kc.c (limited to 'drivers/pps/kc.c') diff --git a/drivers/pps/kc.c b/drivers/pps/kc.c new file mode 100644 index 000000000..4f8fffa7e --- /dev/null +++ b/drivers/pps/kc.c @@ -0,0 +1,119 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * PPS kernel consumer API + * + * Copyright (C) 2009-2010 Alexander Gordeev + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include + +#include "kc.h" + +/* + * Global variables + */ + +/* state variables to bind kernel consumer */ +static DEFINE_SPINLOCK(pps_kc_hardpps_lock); +/* PPS API (RFC 2783): current source and mode for kernel consumer */ +static struct pps_device *pps_kc_hardpps_dev; /* unique pointer to device */ +static int pps_kc_hardpps_mode; /* mode bits for kernel consumer */ + +/* pps_kc_bind - control PPS kernel consumer binding + * @pps: the PPS source + * @bind_args: kernel consumer bind parameters + * + * This function is used to bind or unbind PPS kernel consumer according to + * supplied parameters. Should not be called in interrupt context. + */ +int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args) +{ + /* Check if another consumer is already bound */ + spin_lock_irq(&pps_kc_hardpps_lock); + + /* + * Don't allow PPS_KC_BIND on a removed device. + */ + if (pps->kc_removed) { + spin_unlock_irq(&pps_kc_hardpps_lock); + return -ENODEV; + } + + if (bind_args->edge == 0) + if (pps_kc_hardpps_dev == pps) { + pps_kc_hardpps_mode = 0; + pps_kc_hardpps_dev = NULL; + spin_unlock_irq(&pps_kc_hardpps_lock); + dev_info(&pps->dev, "unbound kernel" + " consumer\n"); + } else { + spin_unlock_irq(&pps_kc_hardpps_lock); + dev_err(&pps->dev, "selected kernel consumer" + " is not bound\n"); + return -EINVAL; + } + else + if (pps_kc_hardpps_dev == NULL || + pps_kc_hardpps_dev == pps) { + pps_kc_hardpps_mode = bind_args->edge; + pps_kc_hardpps_dev = pps; + spin_unlock_irq(&pps_kc_hardpps_lock); + dev_info(&pps->dev, "bound kernel consumer: " + "edge=0x%x\n", bind_args->edge); + } else { + spin_unlock_irq(&pps_kc_hardpps_lock); + dev_err(&pps->dev, "another kernel consumer" + " is already bound\n"); + return -EINVAL; + } + + return 0; +} + +/* pps_kc_remove - unbind kernel consumer on PPS source removal + * @pps: the PPS source + * + * This function is used to disable kernel consumer on PPS source removal + * if this source was bound to PPS kernel consumer. Can be called on any + * source safely. Should not be called in interrupt context. + */ +void pps_kc_remove(struct pps_device *pps) +{ + spin_lock_irq(&pps_kc_hardpps_lock); + + pps->kc_removed = true; + if (pps == pps_kc_hardpps_dev) { + pps_kc_hardpps_mode = 0; + pps_kc_hardpps_dev = NULL; + spin_unlock_irq(&pps_kc_hardpps_lock); + dev_info(&pps->dev, "unbound kernel consumer" + " on device removal\n"); + } else + spin_unlock_irq(&pps_kc_hardpps_lock); +} + +/* pps_kc_event - call hardpps() on PPS event + * @pps: the PPS source + * @ts: PPS event timestamp + * @event: PPS event edge + * + * This function calls hardpps() when an event from bound PPS source occurs. + */ +void pps_kc_event(struct pps_device *pps, struct pps_event_time *ts, + int event) +{ + unsigned long flags; + + /* Pass some events to kernel consumer if activated */ + spin_lock_irqsave(&pps_kc_hardpps_lock, flags); + if (pps == pps_kc_hardpps_dev && event & pps_kc_hardpps_mode) + hardpps(&ts->ts_real, &ts->ts_raw); + spin_unlock_irqrestore(&pps_kc_hardpps_lock, flags); +} -- cgit v1.3.1