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, 184 insertions, 0 deletions

diff --git a/drivers/regulator/max8893.c b/drivers/regulator/max8893.c
new file mode 100644
index 000000000..7a0e44a16
--- /dev/null
+++ b/drivers/regulator/max8893.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+
+static const struct regulator_ops max8893_ops = {
+	.is_enabled		= regulator_is_enabled_regmap,
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
+	.list_voltage		= regulator_list_voltage_linear,
+	.map_voltage		= regulator_map_voltage_linear,
+};
+
+static const struct regulator_desc max8893_regulators[] = {
+	{
+		.name = "BUCK",
+		.supply_name = "in-buck",
+		.of_match = of_match_ptr("buck"),
+		.regulators_node = of_match_ptr("regulators"),
+		.n_voltages = 0x11,
+		.id = 6,
+		.ops = &max8893_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+		.min_uV = 800000,
+		.uV_step = 100000,
+		.vsel_reg = 0x4,
+		.vsel_mask = 0x1f,
+		.enable_reg = 0x0,
+		.enable_mask = BIT(7),
+	},
+	{
+		.name = "LDO1",
+		.supply_name = "in-ldo1",
+		.of_match = of_match_ptr("ldo1"),
+		.regulators_node = of_match_ptr("regulators"),
+		.n_voltages = 0x12,
+		.id = 1,
+		.ops = &max8893_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+		.min_uV = 1600000,
+		.uV_step = 100000,
+		.vsel_reg = 0x5,
+		.vsel_mask = 0x1f,
+		.enable_reg = 0x0,
+		.enable_mask = BIT(5),
+	},
+	{
+		.name = "LDO2",
+		.supply_name = "in-ldo2",
+		.of_match = of_match_ptr("ldo2"),
+		.regulators_node = of_match_ptr("regulators"),
+		.n_voltages = 0x16,
+		.id = 2,
+		.ops = &max8893_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+		.min_uV = 1200000,
+		.uV_step = 100000,
+		.vsel_reg = 0x6,
+		.vsel_mask = 0x1f,
+		.enable_reg = 0x0,
+		.enable_mask = BIT(4),
+	},
+	{
+		.name = "LDO3",
+		.supply_name = "in-ldo3",
+		.of_match = of_match_ptr("ldo3"),
+		.regulators_node = of_match_ptr("regulators"),
+		.n_voltages = 0x12,
+		.id = 3,
+		.ops = &max8893_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+		.min_uV = 1600000,
+		.uV_step = 100000,
+		.vsel_reg = 0x7,
+		.vsel_mask = 0x1f,
+		.enable_reg = 0x0,
+		.enable_mask = BIT(3),
+	},
+	{
+		.name = "LDO4",
+		.supply_name = "in-ldo4",
+		.of_match = of_match_ptr("ldo4"),
+		.regulators_node = of_match_ptr("regulators"),
+		.n_voltages = 0x1a,
+		.id = 4,
+		.ops = &max8893_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+		.min_uV = 800000,
+		.uV_step = 100000,
+		.vsel_reg = 0x8,
+		.vsel_mask = 0x1f,
+		.enable_reg = 0x0,
+		.enable_mask = BIT(2),
+	},
+	{
+		.name = "LDO5",
+		.supply_name = "in-ldo5",
+		.of_match = of_match_ptr("ldo5"),
+		.regulators_node = of_match_ptr("regulators"),
+		.n_voltages = 0x1a,
+		.id = 5,
+		.ops = &max8893_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+		.min_uV = 800000,
+		.uV_step = 100000,
+		.vsel_reg = 0x9,
+		.vsel_mask = 0x1f,
+		.enable_reg = 0x0,
+		.enable_mask = BIT(1),
+	}
+};
+
+static const struct regmap_config max8893_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int max8893_probe(struct i2c_client *i2c)
+{
+	int id, ret;
+	struct regulator_config config = {.dev = &i2c->dev};
+	struct regmap *regmap = devm_regmap_init_i2c(i2c, &max8893_regmap);
+
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
+		return ret;
+	}
+
+	for (id = 0; id < ARRAY_SIZE(max8893_regulators); id++) {
+		struct regulator_dev *rdev;
+		rdev = devm_regulator_register(&i2c->dev,
+					       &max8893_regulators[id],
+					       &config);
+		if (IS_ERR(rdev)) {
+			ret = PTR_ERR(rdev);
+			dev_err(&i2c->dev, "failed to register %s: %d\n",
+				max8893_regulators[id].name, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id max8893_dt_match[] = {
+	{ .compatible = "maxim,max8893" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, max8893_dt_match);
+#endif
+
+static const struct i2c_device_id max8893_ids[] = {
+	{ .name = "max8893" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max8893_ids);
+
+static struct i2c_driver max8893_driver = {
+	.probe		= max8893_probe,
+	.driver		= {
+		.name	= "max8893",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = of_match_ptr(max8893_dt_match),
+	},
+	.id_table	= max8893_ids,
+};
+
+module_i2c_driver(max8893_driver);
+
+MODULE_DESCRIPTION("Maxim MAX8893 PMIC driver");
+MODULE_AUTHOR("Sergey Larin <cerg2010cerg2010@mail.ru>");
+MODULE_LICENSE("GPL");