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, 37 insertions, 0 deletions

diff --git a/include/net/nfc/llc.h b/include/net/nfc/llc.h
new file mode 100644
index 000000000..1f699cb17
--- /dev/null
+++ b/include/net/nfc/llc.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Link Layer Control manager public interface
+ *
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#ifndef __NFC_LLC_H_
+#define __NFC_LLC_H_
+
+#include <net/nfc/hci.h>
+#include <linux/skbuff.h>
+
+#define LLC_NOP_NAME "nop"
+#define LLC_SHDLC_NAME "shdlc"
+
+typedef void (*rcv_to_hci_t) (struct nfc_hci_dev *hdev, struct sk_buff *skb);
+typedef int (*xmit_to_drv_t) (struct nfc_hci_dev *hdev, struct sk_buff *skb);
+typedef void (*llc_failure_t) (struct nfc_hci_dev *hdev, int err);
+
+struct nfc_llc;
+
+struct nfc_llc *nfc_llc_allocate(const char *name, struct nfc_hci_dev *hdev,
+				 xmit_to_drv_t xmit_to_drv,
+				 rcv_to_hci_t rcv_to_hci, int tx_headroom,
+				 int tx_tailroom, llc_failure_t llc_failure);
+void nfc_llc_free(struct nfc_llc *llc);
+
+int nfc_llc_start(struct nfc_llc *llc);
+int nfc_llc_stop(struct nfc_llc *llc);
+void nfc_llc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb);
+int nfc_llc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb);
+
+int nfc_llc_init(void);
+void nfc_llc_exit(void);
+
+#endif /* __NFC_LLC_H_ */