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, 107 insertions, 0 deletions

diff --git a/drivers/base/pinctrl.c b/drivers/base/pinctrl.c
new file mode 100644
index 000000000..0bbc83231
--- /dev/null
+++ b/drivers/base/pinctrl.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver core interface to the pinctrl subsystem.
+ *
+ * Copyright (C) 2012 ST-Ericsson SA
+ * Written on behalf of Linaro for ST-Ericsson
+ * Based on bits of regulator core, gpio core and clk core
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ */
+
+#include <linux/device.h>
+#include <linux/pinctrl/devinfo.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/slab.h>
+
+#include "base.h"
+
+/**
+ * pinctrl_bind_pins() - called by the device core before probe
+ * @dev: the device that is just about to probe
+ */
+int pinctrl_bind_pins(struct device *dev)
+{
+	int ret;
+
+	if (dev_of_node_reused(dev))
+		return 0;
+
+	dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL);
+	if (!dev->pins)
+		return -ENOMEM;
+
+	dev->pins->p = devm_pinctrl_get(dev);
+	if (IS_ERR(dev->pins->p)) {
+		dev_dbg(dev, "no pinctrl handle\n");
+		ret = PTR_ERR(dev->pins->p);
+		goto cleanup_alloc;
+	}
+
+	dev->pins->default_state = pinctrl_lookup_state(dev->pins->p,
+					PINCTRL_STATE_DEFAULT);
+	if (IS_ERR(dev->pins->default_state)) {
+		dev_dbg(dev, "no default pinctrl state\n");
+		ret = 0;
+		goto cleanup_get;
+	}
+
+	dev->pins->init_state = pinctrl_lookup_state(dev->pins->p,
+					PINCTRL_STATE_INIT);
+	if (IS_ERR(dev->pins->init_state)) {
+		/* Not supplying this state is perfectly legal */
+		dev_dbg(dev, "no init pinctrl state\n");
+
+		ret = pinctrl_select_state(dev->pins->p,
+					   dev->pins->default_state);
+	} else {
+		ret = pinctrl_select_state(dev->pins->p, dev->pins->init_state);
+	}
+
+	if (ret) {
+		dev_dbg(dev, "failed to activate initial pinctrl state\n");
+		goto cleanup_get;
+	}
+
+#ifdef CONFIG_PM
+	/*
+	 * If power management is enabled, we also look for the optional
+	 * sleep and idle pin states, with semantics as defined in
+	 * <linux/pinctrl/pinctrl-state.h>
+	 */
+	dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p,
+					PINCTRL_STATE_SLEEP);
+	if (IS_ERR(dev->pins->sleep_state))
+		/* Not supplying this state is perfectly legal */
+		dev_dbg(dev, "no sleep pinctrl state\n");
+
+	dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p,
+					PINCTRL_STATE_IDLE);
+	if (IS_ERR(dev->pins->idle_state))
+		/* Not supplying this state is perfectly legal */
+		dev_dbg(dev, "no idle pinctrl state\n");
+#endif
+
+	return 0;
+
+	/*
+	 * If no pinctrl handle or default state was found for this device,
+	 * let's explicitly free the pin container in the device, there is
+	 * no point in keeping it around.
+	 */
+cleanup_get:
+	devm_pinctrl_put(dev->pins->p);
+cleanup_alloc:
+	devm_kfree(dev, dev->pins);
+	dev->pins = NULL;
+
+	/* Return deferrals */
+	if (ret == -EPROBE_DEFER)
+		return ret;
+	/* Return serious errors */
+	if (ret == -EINVAL)
+		return ret;
+	/* We ignore errors like -ENOENT meaning no pinctrl state */
+
+	return 0;
+}