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, 30 insertions, 0 deletions

diff --git a/include/uapi/fwctl/bnxt.h b/include/uapi/fwctl/bnxt.h
new file mode 100644
index 000000000..398c1ad0c
--- /dev/null
+++ b/include/uapi/fwctl/bnxt.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (c) 2026, Broadcom Inc
+ */
+
+#ifndef _UAPI_FWCTL_BNXT_H_
+#define _UAPI_FWCTL_BNXT_H_
+
+#include <linux/types.h>
+
+enum fwctl_bnxt_commands {
+	FWCTL_BNXT_INLINE_COMMANDS = 0,
+	FWCTL_BNXT_QUERY_COMMANDS,
+	FWCTL_BNXT_SEND_COMMANDS,
+	FWCTL_BNXT_DMA_COMMANDS,
+};
+
+/**
+ * struct fwctl_info_bnxt - ioctl(FWCTL_INFO) out_device_data
+ * @uctx_caps: The command capabilities driver accepts.
+ *
+ * Return basic information about the FW interface available.
+ */
+struct fwctl_info_bnxt {
+	__u32 uctx_caps;
+};
+
+#define FWCTL_BNXT_MAX_DMABUF	0x10000   /* 64 KiB */
+
+#endif