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/regulator/dummy.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 drivers/regulator/dummy.c (limited to 'drivers/regulator/dummy.c') diff --git a/drivers/regulator/dummy.c b/drivers/regulator/dummy.c new file mode 100644 index 000000000..c3e416fd3 --- /dev/null +++ b/drivers/regulator/dummy.c @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * dummy.c + * + * Copyright 2010 Wolfson Microelectronics PLC. + * + * Author: Mark Brown + * + * This is useful for systems with mixed controllable and + * non-controllable regulators, as well as for allowing testing on + * systems with no controllable regulators. + */ + +#include +#include +#include +#include +#include + +#include "dummy.h" + +struct regulator_dev *dummy_regulator_rdev; + +static const struct regulator_init_data dummy_initdata = { + .constraints = { + .always_on = 1, + }, +}; + +static const struct regulator_ops dummy_ops; + +static const struct regulator_desc dummy_desc = { + .name = "regulator-dummy", + .id = -1, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .ops = &dummy_ops, +}; + +static int dummy_regulator_probe(struct faux_device *fdev) +{ + struct regulator_config config = { }; + int ret; + + config.dev = &fdev->dev; + config.init_data = &dummy_initdata; + + dummy_regulator_rdev = devm_regulator_register(&fdev->dev, &dummy_desc, + &config); + if (IS_ERR(dummy_regulator_rdev)) { + ret = PTR_ERR(dummy_regulator_rdev); + pr_err("Failed to register regulator: %d\n", ret); + return ret; + } + + return 0; +} + +static struct faux_device_ops dummy_regulator_driver = { + .probe = dummy_regulator_probe, +}; + +static struct faux_device *dummy_fdev; + +void __init regulator_dummy_init(void) +{ + dummy_fdev = faux_device_create("reg-dummy", NULL, &dummy_regulator_driver); + if (!dummy_fdev) { + pr_err("Failed to allocate dummy regulator device\n"); + return; + } +} -- cgit v1.3.1