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/fixed-helper.c | 63 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 drivers/regulator/fixed-helper.c (limited to 'drivers/regulator/fixed-helper.c') diff --git a/drivers/regulator/fixed-helper.c b/drivers/regulator/fixed-helper.c new file mode 100644 index 000000000..ba5551ac0 --- /dev/null +++ b/drivers/regulator/fixed-helper.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +struct fixed_regulator_data { + struct fixed_voltage_config cfg; + struct regulator_init_data init_data; + struct platform_device pdev; +}; + +static void regulator_fixed_release(struct device *dev) +{ + struct fixed_regulator_data *data = container_of(dev, + struct fixed_regulator_data, pdev.dev); + kfree_const(data->cfg.supply_name); + kfree(data); +} + +/** + * regulator_register_always_on - register an always-on regulator with a fixed name + * @id: platform device id + * @name: name to be used for the regulator + * @supplies: consumers for this regulator + * @num_supplies: number of consumers + * @uv: voltage in microvolts + * + * Return: Pointer to registered platform device, or %NULL if memory allocation fails. + */ +struct platform_device *regulator_register_always_on(int id, const char *name, + struct regulator_consumer_supply *supplies, int num_supplies, int uv) +{ + struct fixed_regulator_data *data; + + data = kzalloc_obj(*data); + if (!data) + return NULL; + + data->cfg.supply_name = kstrdup_const(name, GFP_KERNEL); + if (!data->cfg.supply_name) { + kfree(data); + return NULL; + } + + data->cfg.microvolts = uv; + data->cfg.enabled_at_boot = 1; + data->cfg.init_data = &data->init_data; + + data->init_data.constraints.always_on = 1; + data->init_data.consumer_supplies = supplies; + data->init_data.num_consumer_supplies = num_supplies; + + data->pdev.name = "reg-fixed-voltage"; + data->pdev.id = id; + data->pdev.dev.platform_data = &data->cfg; + data->pdev.dev.release = regulator_fixed_release; + + platform_device_register(&data->pdev); + + return &data->pdev; +} -- cgit v1.3.1