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/mtd/chips/chipreg.c | 102 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 drivers/mtd/chips/chipreg.c (limited to 'drivers/mtd/chips/chipreg.c') diff --git a/drivers/mtd/chips/chipreg.c b/drivers/mtd/chips/chipreg.c new file mode 100644 index 000000000..a05e10368 --- /dev/null +++ b/drivers/mtd/chips/chipreg.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Registration for chip drivers + * + */ + +#include +#include +#include +#include +#include +#include +#include + +static DEFINE_SPINLOCK(chip_drvs_lock); +static LIST_HEAD(chip_drvs_list); + +void register_mtd_chip_driver(struct mtd_chip_driver *drv) +{ + spin_lock(&chip_drvs_lock); + list_add(&drv->list, &chip_drvs_list); + spin_unlock(&chip_drvs_lock); +} + +void unregister_mtd_chip_driver(struct mtd_chip_driver *drv) +{ + spin_lock(&chip_drvs_lock); + list_del(&drv->list); + spin_unlock(&chip_drvs_lock); +} + +static struct mtd_chip_driver *get_mtd_chip_driver (const char *name) +{ + struct mtd_chip_driver *ret = NULL, *this; + + spin_lock(&chip_drvs_lock); + + list_for_each_entry(this, &chip_drvs_list, list) { + if (!strcmp(this->name, name)) { + ret = this; + break; + } + } + if (ret && !try_module_get(ret->module)) + ret = NULL; + + spin_unlock(&chip_drvs_lock); + + return ret; +} + + /* Hide all the horrid details, like some silly person taking + get_module_symbol() away from us, from the caller. */ + +struct mtd_info *do_map_probe(const char *name, struct map_info *map) +{ + struct mtd_chip_driver *drv; + struct mtd_info *ret; + + drv = get_mtd_chip_driver(name); + + if (!drv && !request_module("%s", name)) + drv = get_mtd_chip_driver(name); + + if (!drv) + return NULL; + + ret = drv->probe(map); + + /* We decrease the use count here. It may have been a + probe-only module, which is no longer required from this + point, having given us a handle on (and increased the use + count of) the actual driver code. + */ + module_put(drv->module); + + return ret; +} +/* + * Destroy an MTD device which was created for a map device. + * Make sure the MTD device is already unregistered before calling this + */ +void map_destroy(struct mtd_info *mtd) +{ + struct map_info *map = mtd->priv; + + if (map->fldrv->destroy) + map->fldrv->destroy(mtd); + + module_put(map->fldrv->module); + + kfree(mtd); +} + +EXPORT_SYMBOL(register_mtd_chip_driver); +EXPORT_SYMBOL(unregister_mtd_chip_driver); +EXPORT_SYMBOL(do_map_probe); +EXPORT_SYMBOL(map_destroy); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David Woodhouse "); +MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers"); -- cgit v1.3.1