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, 223 insertions, 0 deletions

diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
new file mode 100644
index 000000000..ba6343321
--- /dev/null
+++ b/drivers/clocksource/timer-of.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017, Linaro Ltd.  All rights reserved.
+ *
+ * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
+ */
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+
+#include "timer-of.h"
+
+/**
+ * timer_of_irq_exit - Release the interrupt
+ * @of_irq: an of_timer_irq structure pointer
+ *
+ * Free the irq resource
+ */
+static void timer_of_irq_exit(struct of_timer_irq *of_irq)
+{
+	struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
+
+	struct clock_event_device *clkevt = &to->clkevt;
+
+	free_irq(of_irq->irq, clkevt);
+}
+
+/**
+ * timer_of_irq_init - Request the interrupt
+ * @np: a device tree node pointer
+ * @of_irq: an of_timer_irq structure pointer
+ *
+ * Get the interrupt number from the DT from its definition and
+ * request it. The interrupt is gotten by falling back the following way:
+ *
+ * - Get interrupt number by name
+ * - Get interrupt number by index
+ *
+ * Returns 0 on success, < 0 otherwise
+ */
+static int timer_of_irq_init(struct device_node *np,
+			     struct of_timer_irq *of_irq)
+{
+	int ret;
+	struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
+	struct clock_event_device *clkevt = &to->clkevt;
+
+	if (of_irq->name) {
+		of_irq->irq = ret = of_irq_get_byname(np, of_irq->name);
+		if (ret < 0) {
+			pr_err("Failed to get interrupt %s for %pOF\n",
+			       of_irq->name, np);
+			return ret;
+		}
+	} else	{
+		of_irq->irq = irq_of_parse_and_map(np, of_irq->index);
+	}
+	if (!of_irq->irq) {
+		pr_err("Failed to map interrupt for %pOF\n", np);
+		return -EINVAL;
+	}
+
+	ret = request_irq(of_irq->irq, of_irq->handler,
+			  of_irq->flags ? of_irq->flags : IRQF_TIMER,
+			  np->full_name, clkevt);
+	if (ret) {
+		pr_err("Failed to request irq %d for %pOF\n", of_irq->irq, np);
+		return ret;
+	}
+
+	clkevt->irq = of_irq->irq;
+
+	return 0;
+}
+
+/**
+ * timer_of_clk_exit - Release the clock resources
+ * @of_clk: a of_timer_clk structure pointer
+ *
+ * Disables and releases the refcount on the clk
+ */
+static void timer_of_clk_exit(struct of_timer_clk *of_clk)
+{
+	of_clk->rate = 0;
+	clk_disable_unprepare(of_clk->clk);
+	clk_put(of_clk->clk);
+}
+
+/**
+ * timer_of_clk_init - Initialize the clock resources
+ * @np: a device tree node pointer
+ * @of_clk: a of_timer_clk structure pointer
+ *
+ * Get the clock by name or by index, enable it and get the rate
+ *
+ * Returns 0 on success, < 0 otherwise
+ */
+static int timer_of_clk_init(struct device_node *np,
+			     struct of_timer_clk *of_clk)
+{
+	int ret;
+
+	of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) :
+		of_clk_get(np, of_clk->index);
+	if (IS_ERR(of_clk->clk)) {
+		ret = PTR_ERR(of_clk->clk);
+		if (ret != -EPROBE_DEFER)
+			pr_err("Failed to get clock for %pOF\n", np);
+		goto out;
+	}
+
+	ret = clk_prepare_enable(of_clk->clk);
+	if (ret) {
+		pr_err("Failed for enable clock for %pOF\n", np);
+		goto out_clk_put;
+	}
+
+	of_clk->rate = clk_get_rate(of_clk->clk);
+	if (!of_clk->rate) {
+		ret = -EINVAL;
+		pr_err("Failed to get clock rate for %pOF\n", np);
+		goto out_clk_disable;
+	}
+
+	of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ);
+out:
+	return ret;
+
+out_clk_disable:
+	clk_disable_unprepare(of_clk->clk);
+out_clk_put:
+	clk_put(of_clk->clk);
+
+	goto out;
+}
+
+static void timer_of_base_exit(struct of_timer_base *of_base)
+{
+	iounmap(of_base->base);
+}
+
+static  int timer_of_base_init(struct device_node *np,
+			       struct of_timer_base *of_base)
+{
+	of_base->base = of_base->name ?
+		of_io_request_and_map(np, of_base->index, of_base->name) :
+		of_iomap(np, of_base->index);
+	if (IS_ERR_OR_NULL(of_base->base)) {
+		pr_err("Failed to iomap (%s:%s)\n", np->name, of_base->name);
+		return of_base->base ? PTR_ERR(of_base->base) : -ENOMEM;
+	}
+
+	return 0;
+}
+
+int timer_of_init(struct device_node *np, struct timer_of *to)
+{
+	int ret = -EINVAL;
+	int flags = 0;
+
+	if (to->flags & TIMER_OF_BASE) {
+		ret = timer_of_base_init(np, &to->of_base);
+		if (ret)
+			goto out_fail;
+		flags |= TIMER_OF_BASE;
+	}
+
+	if (to->flags & TIMER_OF_CLOCK) {
+		ret = timer_of_clk_init(np, &to->of_clk);
+		if (ret)
+			goto out_fail;
+		flags |= TIMER_OF_CLOCK;
+	}
+
+	if (to->flags & TIMER_OF_IRQ) {
+		ret = timer_of_irq_init(np, &to->of_irq);
+		if (ret)
+			goto out_fail;
+		flags |= TIMER_OF_IRQ;
+	}
+
+	if (!to->clkevt.name)
+		to->clkevt.name = np->full_name;
+
+	to->np = np;
+
+	return ret;
+
+out_fail:
+	if (flags & TIMER_OF_IRQ)
+		timer_of_irq_exit(&to->of_irq);
+
+	if (flags & TIMER_OF_CLOCK)
+		timer_of_clk_exit(&to->of_clk);
+
+	if (flags & TIMER_OF_BASE)
+		timer_of_base_exit(&to->of_base);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(timer_of_init);
+
+/**
+ * timer_of_cleanup - release timer_of resources
+ * @to: timer_of structure
+ *
+ * Release the resources that has been used in timer_of_init().
+ * This function should be called in init error cases
+ */
+void timer_of_cleanup(struct timer_of *to)
+{
+	if (to->flags & TIMER_OF_IRQ)
+		timer_of_irq_exit(&to->of_irq);
+
+	if (to->flags & TIMER_OF_CLOCK)
+		timer_of_clk_exit(&to->of_clk);
+
+	if (to->flags & TIMER_OF_BASE)
+		timer_of_base_exit(&to->of_base);
+}
+EXPORT_SYMBOL_GPL(timer_of_cleanup);