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, 103 insertions, 0 deletions

diff --git a/include/soc/tegra/ivc.h b/include/soc/tegra/ivc.h
new file mode 100644
index 000000000..be45d5f5a
--- /dev/null
+++ b/include/soc/tegra/ivc.h
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#ifndef __TEGRA_IVC_H
+#define __TEGRA_IVC_H
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/iosys-map.h>
+#include <linux/types.h>
+
+struct tegra_ivc_header;
+
+struct tegra_ivc {
+	struct device *peer;
+
+	struct {
+		struct iosys_map map;
+		unsigned int position;
+		dma_addr_t phys;
+	} rx, tx;
+
+	void (*notify)(struct tegra_ivc *ivc, void *data);
+	void *notify_data;
+
+	unsigned int num_frames;
+	size_t frame_size;
+};
+
+/**
+ * tegra_ivc_read_get_next_frame - Peek at the next frame to receive
+ * @ivc		pointer of the IVC channel
+ *
+ * Peek at the next frame to be received, without removing it from
+ * the queue.
+ *
+ * Returns a pointer to the frame, or an error encoded pointer.
+ */
+int tegra_ivc_read_get_next_frame(struct tegra_ivc *ivc, struct iosys_map *map);
+
+/**
+ * tegra_ivc_read_advance - Advance the read queue
+ * @ivc		pointer of the IVC channel
+ *
+ * Advance the read queue
+ *
+ * Returns 0, or a negative error value if failed.
+ */
+int tegra_ivc_read_advance(struct tegra_ivc *ivc);
+
+/**
+ * tegra_ivc_write_get_next_frame - Poke at the next frame to transmit
+ * @ivc		pointer of the IVC channel
+ *
+ * Get access to the next frame.
+ *
+ * Returns a pointer to the frame, or an error encoded pointer.
+ */
+int tegra_ivc_write_get_next_frame(struct tegra_ivc *ivc, struct iosys_map *map);
+
+/**
+ * tegra_ivc_write_advance - Advance the write queue
+ * @ivc		pointer of the IVC channel
+ *
+ * Advance the write queue
+ *
+ * Returns 0, or a negative error value if failed.
+ */
+int tegra_ivc_write_advance(struct tegra_ivc *ivc);
+
+/**
+ * tegra_ivc_notified - handle internal messages
+ * @ivc		pointer of the IVC channel
+ *
+ * This function must be called following every notification.
+ *
+ * Returns 0 if the channel is ready for communication, or -EAGAIN if a channel
+ * reset is in progress.
+ */
+int tegra_ivc_notified(struct tegra_ivc *ivc);
+
+/**
+ * tegra_ivc_reset - initiates a reset of the shared memory state
+ * @ivc		pointer of the IVC channel
+ *
+ * This function must be called after a channel is reserved before it is used
+ * for communication. The channel will be ready for use when a subsequent call
+ * to notify the remote of the channel reset.
+ */
+void tegra_ivc_reset(struct tegra_ivc *ivc);
+
+size_t tegra_ivc_align(size_t size);
+unsigned tegra_ivc_total_queue_size(unsigned queue_size);
+int tegra_ivc_init(struct tegra_ivc *ivc, struct device *peer, const struct iosys_map *rx,
+		   dma_addr_t rx_phys, const struct iosys_map *tx, dma_addr_t tx_phys,
+		   unsigned int num_frames, size_t frame_size,
+		   void (*notify)(struct tegra_ivc *ivc, void *data),
+		   void *data);
+void tegra_ivc_cleanup(struct tegra_ivc *ivc);
+
+#endif /* __TEGRA_IVC_H */