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, 36 insertions, 0 deletions

diff --git a/drivers/ipack/devices/ipoctal.h b/drivers/ipack/devices/ipoctal.h
new file mode 100644
index 000000000..773dc41bd
--- /dev/null
+++ b/drivers/ipack/devices/ipoctal.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * driver for the IPOCTAL boards
+ *
+ * Copyright (C) 2009-2012 CERN (www.cern.ch)
+ * Author: Nicolas Serafini, EIC2 SA
+ * Author: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
+ */
+
+#ifndef _IPOCTAL_H_
+#define _IPOCTAL_H_
+
+#define NR_CHANNELS		8
+#define IPOCTAL_MAX_BOARDS	16
+#define MAX_DEVICES		(NR_CHANNELS * IPOCTAL_MAX_BOARDS)
+
+/**
+ * struct ipoctal_stats -- Stats since last reset
+ *
+ * @tx: Number of transmitted bytes
+ * @rx: Number of received bytes
+ * @overrun: Number of overrun errors
+ * @parity_err: Number of parity errors
+ * @framing_err: Number of framing errors
+ * @rcv_break: Number of break received
+ */
+struct ipoctal_stats {
+	unsigned long tx;
+	unsigned long rx;
+	unsigned long overrun_err;
+	unsigned long parity_err;
+	unsigned long framing_err;
+	unsigned long rcv_break;
+};
+
+#endif /* _IPOCTAL_H_ */