arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__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 <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig
new file mode 100644
index 000000000..e1651d51c
--- /dev/null
+++ b/drivers/pps/Kconfig
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# PPS support configuration
+#
+
+menuconfig PPS
+	tristate "PPS support"
+	help
+	  PPS (Pulse Per Second) is a special pulse provided by some GPS
+	  antennae. Userland can use it to get a high-precision time
+	  reference.
+
+	  Some antennae's PPS signals are connected with the CD (Carrier
+	  Detect) pin of the serial line they use to communicate with the
+	  host. In this case use the SERIAL_LINE client support.
+
+	  Some antennae's PPS signals are connected with some special host
+	  inputs so you have to enable the corresponding client support.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pps_core.ko.
+
+if PPS
+
+config PPS_DEBUG
+	bool "PPS debugging messages"
+	help
+	  Say Y here if you want the PPS support to produce a bunch of debug
+	  messages to the system log.  Select this if you are having a
+	  problem with PPS support and want to see more of what is going on.
+
+config NTP_PPS
+	bool "PPS kernel consumer support"
+	depends on !NO_HZ_COMMON
+	help
+	  This option adds support for direct in-kernel time
+	  synchronization using an external PPS signal.
+
+	  It doesn't work on tickless systems at the moment.
+
+source "drivers/pps/clients/Kconfig"
+
+source "drivers/pps/generators/Kconfig"
+
+endif # PPS