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/char/nwbutton.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 drivers/char/nwbutton.h (limited to 'drivers/char/nwbutton.h') diff --git a/drivers/char/nwbutton.h b/drivers/char/nwbutton.h new file mode 100644 index 000000000..f2b9fdc1f --- /dev/null +++ b/drivers/char/nwbutton.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NWBUTTON_H +#define __NWBUTTON_H + +/* + * NetWinder Button Driver- + * Copyright (C) Alex Holden 1998, 1999. + */ + +#ifdef __NWBUTTON_C /* Actually compiling the driver itself */ + +/* Various defines: */ + +#define NUM_PRESSES_REBOOT 2 /* How many presses to activate shutdown */ +#define BUTTON_DELAY 30 /* How many jiffies for sequence to end */ +#define VERSION "0.3" /* Driver version number */ + +/* Structure definitions: */ + +struct button_callback { + void (*callback) (void); + int count; +}; + +/* Function prototypes: */ + +static void button_sequence_finished(struct timer_list *unused); +static irqreturn_t button_handler (int irq, void *dev_id); +int button_init (void); +int button_add_callback (void (*callback) (void), int count); +int button_del_callback (void (*callback) (void)); +static void button_consume_callbacks (int bpcount); + +#else /* Not compiling the driver itself */ + +extern int button_add_callback (void (*callback) (void), int count); +extern int button_del_callback (void (*callback) (void)); + +#endif /* __NWBUTTON_C */ +#endif /* __NWBUTTON_H */ -- cgit v1.3.1