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, 57 insertions, 0 deletions

diff --git a/Documentation/devicetree/kernel-api.rst b/Documentation/devicetree/kernel-api.rst
new file mode 100644
index 000000000..b7429e6ed
--- /dev/null
+++ b/Documentation/devicetree/kernel-api.rst
@@ -0,0 +1,57 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. _devicetree:
+
+======================================
+DeviceTree Kernel API
+======================================
+
+Core functions
+--------------
+
+.. kernel-doc:: drivers/of/base.c
+   :export:
+
+.. kernel-doc:: include/linux/of.h
+   :internal:
+
+.. kernel-doc:: drivers/of/property.c
+   :export:
+
+.. kernel-doc:: include/linux/of_graph.h
+   :internal:
+
+.. kernel-doc:: drivers/of/address.c
+   :export:
+
+.. kernel-doc:: drivers/of/irq.c
+   :export:
+
+.. kernel-doc:: drivers/of/fdt.c
+   :export:
+
+Driver model functions
+----------------------
+
+.. kernel-doc:: include/linux/of_device.h
+   :internal:
+
+.. kernel-doc:: drivers/of/device.c
+   :export:
+
+.. kernel-doc:: include/linux/of_platform.h
+   :internal:
+
+.. kernel-doc:: drivers/of/platform.c
+   :export:
+
+Overlay and Dynamic DT functions
+--------------------------------
+
+.. kernel-doc:: drivers/of/resolver.c
+   :export:
+
+.. kernel-doc:: drivers/of/dynamic.c
+   :export:
+
+.. kernel-doc:: drivers/of/overlay.c
+   :export: