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, 96 insertions, 0 deletions

diff --git a/drivers/net/phy/teranetics.c b/drivers/net/phy/teranetics.c
new file mode 100644
index 000000000..46c5ff7d7
--- /dev/null
+++ b/drivers/net/phy/teranetics.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Teranetics PHY
+ *
+ * Author: Shaohui Xie <Shaohui.Xie@freescale.com>
+ *
+ * Copyright 2015 Freescale Semiconductor, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/ethtool.h>
+#include <linux/mdio.h>
+#include <linux/phy.h>
+
+MODULE_DESCRIPTION("Teranetics PHY driver");
+MODULE_AUTHOR("Shaohui Xie <Shaohui.Xie@freescale.com>");
+MODULE_LICENSE("GPL v2");
+
+#define PHY_ID_TN2020	0x00a19410
+#define MDIO_PHYXS_LNSTAT_SYNC0	0x0001
+#define MDIO_PHYXS_LNSTAT_SYNC1	0x0002
+#define MDIO_PHYXS_LNSTAT_SYNC2	0x0004
+#define MDIO_PHYXS_LNSTAT_SYNC3	0x0008
+#define MDIO_PHYXS_LNSTAT_ALIGN 0x1000
+
+#define MDIO_PHYXS_LANE_READY	(MDIO_PHYXS_LNSTAT_SYNC0 | \
+				MDIO_PHYXS_LNSTAT_SYNC1 | \
+				MDIO_PHYXS_LNSTAT_SYNC2 | \
+				MDIO_PHYXS_LNSTAT_SYNC3 | \
+				MDIO_PHYXS_LNSTAT_ALIGN)
+
+static int teranetics_aneg_done(struct phy_device *phydev)
+{
+	/* auto negotiation state can only be checked when using copper
+	 * port, if using fiber port, just lie it's done.
+	 */
+	if (!phy_read_mmd(phydev, MDIO_MMD_VEND1, 93))
+		return genphy_c45_aneg_done(phydev);
+
+	return 1;
+}
+
+static int teranetics_read_status(struct phy_device *phydev)
+{
+	int reg;
+
+	phydev->link = 1;
+
+	phydev->speed = SPEED_10000;
+	phydev->duplex = DUPLEX_FULL;
+
+	if (!phy_read_mmd(phydev, MDIO_MMD_VEND1, 93)) {
+		reg = phy_read_mmd(phydev, MDIO_MMD_PHYXS, MDIO_PHYXS_LNSTAT);
+		if (reg < 0 ||
+		    !((reg & MDIO_PHYXS_LANE_READY) == MDIO_PHYXS_LANE_READY)) {
+			phydev->link = 0;
+			return 0;
+		}
+
+		reg = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1);
+		if (reg < 0 || !(reg & MDIO_STAT1_LSTATUS))
+			phydev->link = 0;
+	}
+
+	return 0;
+}
+
+static int teranetics_match_phy_device(struct phy_device *phydev,
+				       const struct phy_driver *phydrv)
+{
+	return phydev->c45_ids.device_ids[3] == PHY_ID_TN2020;
+}
+
+static struct phy_driver teranetics_driver[] = {
+{
+	.phy_id		= PHY_ID_TN2020,
+	.phy_id_mask	= 0xffffffff,
+	.name		= "Teranetics TN2020",
+	.features       = PHY_10GBIT_FEATURES,
+	.aneg_done	= teranetics_aneg_done,
+	.config_aneg    = gen10g_config_aneg,
+	.read_status	= teranetics_read_status,
+	.match_phy_device = teranetics_match_phy_device,
+},
+};
+
+module_phy_driver(teranetics_driver);
+
+static const struct mdio_device_id __maybe_unused teranetics_tbl[] = {
+	{ PHY_ID_TN2020, 0xffffffff },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(mdio, teranetics_tbl);