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, 75 insertions, 0 deletions

diff --git a/drivers/hid/hid-evision.c b/drivers/hid/hid-evision.c
new file mode 100644
index 000000000..3e7f43ab8
--- /dev/null
+++ b/drivers/hid/hid-evision.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID driver for EVision devices
+ *  For now, only ignore bogus consumer reports
+ *  sent after the keyboard has been configured
+ *
+ *  Copyright (c) 2022 Philippe Valembois
+ */
+
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+static int evision_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+		struct hid_field *field, struct hid_usage *usage,
+		unsigned long **bit, int *max)
+{
+	/* mapping only applies to USB_DEVICE_ID_EVISION_ICL01 */
+	if (hdev->product != USB_DEVICE_ID_EVISION_ICL01)
+		return 0;
+
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_CONSUMER)
+		return 0;
+
+	/* Ignore key down event */
+	if ((usage->hid & HID_USAGE) >> 8 == 0x05)
+		return -1;
+	/* Ignore key up event */
+	if ((usage->hid & HID_USAGE) >> 8 == 0x06)
+		return -1;
+
+	switch (usage->hid & HID_USAGE) {
+	/* Ignore configuration saved event */
+	case 0x0401: return -1;
+	/* Ignore reset event */
+	case 0x0402: return -1;
+	}
+	return 0;
+}
+
+#define REP_DSC_SIZE 236
+#define USAGE_MAX_INDEX 59
+
+static const __u8 *evision_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
+{
+	if (hdev->product == USB_DEVICE_ID_EV_TELINK_RECEIVER &&
+	    *rsize == REP_DSC_SIZE && rdesc[USAGE_MAX_INDEX] == 0x29 &&
+	    rdesc[USAGE_MAX_INDEX + 1] == 3) {
+		hid_info(hdev, "fixing EVision:TeLink Receiver report descriptor\n");
+		rdesc[USAGE_MAX_INDEX + 1] = 5; // change usage max from 3 to 5
+	}
+	return rdesc;
+}
+
+static const struct hid_device_id evision_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_EVISION, USB_DEVICE_ID_EVISION_ICL01) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_EVISION, USB_DEVICE_ID_EV_TELINK_RECEIVER) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, evision_devices);
+
+static struct hid_driver evision_driver = {
+	.name = "evision",
+	.id_table = evision_devices,
+	.input_mapping = evision_input_mapping,
+	.report_fixup = evision_report_fixup,
+};
+module_hid_driver(evision_driver);
+
+MODULE_DESCRIPTION("HID driver for EVision devices");
+MODULE_LICENSE("GPL");