ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

4 files changed, 381 insertions, 0 deletions

diff --git a/drivers/pmdomain/actions/Kconfig b/drivers/pmdomain/actions/Kconfig
new file mode 100644
index 000000000..1aca2058a
--- /dev/null
+++ b/drivers/pmdomain/actions/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+if ARCH_ACTIONS || COMPILE_TEST
+
+config OWL_PM_DOMAINS_HELPER
+	bool
+
+config OWL_PM_DOMAINS
+	bool "Actions Semi SPS power domains"
+	depends on PM
+	select OWL_PM_DOMAINS_HELPER
+	select PM_GENERIC_DOMAINS
+	help
+	  Say 'y' here to enable support for Smart Power System (SPS)
+	  power-gating on Actions Semiconductor S500, S700 and S900 SoCs.
+	  If unsure, say 'n'.
+
+endif
diff --git a/drivers/pmdomain/actions/Makefile b/drivers/pmdomain/actions/Makefile
new file mode 100644
index 000000000..7e8aa473d
--- /dev/null
+++ b/drivers/pmdomain/actions/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+obj-$(CONFIG_OWL_PM_DOMAINS_HELPER)	+= owl-sps-helper.o
+obj-$(CONFIG_OWL_PM_DOMAINS)		+= owl-sps.o
diff --git a/drivers/pmdomain/actions/owl-sps-helper.c b/drivers/pmdomain/actions/owl-sps-helper.c
new file mode 100644
index 000000000..e3f36603d
--- /dev/null
+++ b/drivers/pmdomain/actions/owl-sps-helper.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Actions Semi Owl Smart Power System (SPS) shared helpers
+ *
+ * Copyright 2012 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * Copyright (c) 2017 Andreas Färber
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/soc/actions/owl-sps.h>
+
+#define OWL_SPS_PG_CTL	0x0
+
+int owl_sps_set_pg(void __iomem *base, u32 pwr_mask, u32 ack_mask, bool enable)
+{
+	u32 val;
+	bool ack;
+	int timeout;
+
+	val = readl(base + OWL_SPS_PG_CTL);
+	ack = val & ack_mask;
+	if (ack == enable)
+		return 0;
+
+	if (enable)
+		val |= pwr_mask;
+	else
+		val &= ~pwr_mask;
+
+	writel(val, base + OWL_SPS_PG_CTL);
+
+	for (timeout = 5000; timeout > 0; timeout -= 50) {
+		val = readl(base + OWL_SPS_PG_CTL);
+		if ((val & ack_mask) == (enable ? ack_mask : 0))
+			break;
+		udelay(50);
+	}
+	if (timeout <= 0)
+		return -ETIMEDOUT;
+
+	udelay(10);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(owl_sps_set_pg);
diff --git a/drivers/pmdomain/actions/owl-sps.c b/drivers/pmdomain/actions/owl-sps.c
new file mode 100644
index 000000000..bf5eb80cc
--- /dev/null
+++ b/drivers/pmdomain/actions/owl-sps.c
@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Actions Semi Owl Smart Power System (SPS)
+ *
+ * Copyright 2012 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * Copyright (c) 2017 Andreas Färber
+ */
+
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/pm_domain.h>
+#include <linux/soc/actions/owl-sps.h>
+#include <dt-bindings/power/owl-s500-powergate.h>
+#include <dt-bindings/power/owl-s700-powergate.h>
+#include <dt-bindings/power/owl-s900-powergate.h>
+
+struct owl_sps_domain_info {
+	const char *name;
+	int pwr_bit;
+	int ack_bit;
+	unsigned int genpd_flags;
+};
+
+struct owl_sps_info {
+	unsigned num_domains;
+	const struct owl_sps_domain_info *domains;
+};
+
+struct owl_sps {
+	struct device *dev;
+	const struct owl_sps_info *info;
+	void __iomem *base;
+	struct genpd_onecell_data genpd_data;
+	struct generic_pm_domain *domains[];
+};
+
+#define to_owl_pd(gpd) container_of(gpd, struct owl_sps_domain, genpd)
+
+struct owl_sps_domain {
+	struct generic_pm_domain genpd;
+	const struct owl_sps_domain_info *info;
+	struct owl_sps *sps;
+};
+
+static int owl_sps_set_power(struct owl_sps_domain *pd, bool enable)
+{
+	u32 pwr_mask, ack_mask;
+
+	ack_mask = BIT(pd->info->ack_bit);
+	pwr_mask = BIT(pd->info->pwr_bit);
+
+	return owl_sps_set_pg(pd->sps->base, pwr_mask, ack_mask, enable);
+}
+
+static int owl_sps_power_on(struct generic_pm_domain *domain)
+{
+	struct owl_sps_domain *pd = to_owl_pd(domain);
+
+	dev_dbg(pd->sps->dev, "%s power on", pd->info->name);
+
+	return owl_sps_set_power(pd, true);
+}
+
+static int owl_sps_power_off(struct generic_pm_domain *domain)
+{
+	struct owl_sps_domain *pd = to_owl_pd(domain);
+
+	dev_dbg(pd->sps->dev, "%s power off", pd->info->name);
+
+	return owl_sps_set_power(pd, false);
+}
+
+static int owl_sps_init_domain(struct owl_sps *sps, int index)
+{
+	struct owl_sps_domain *pd;
+
+	pd = devm_kzalloc(sps->dev, sizeof(*pd), GFP_KERNEL);
+	if (!pd)
+		return -ENOMEM;
+
+	pd->info = &sps->info->domains[index];
+	pd->sps = sps;
+
+	pd->genpd.name = pd->info->name;
+	pd->genpd.power_on = owl_sps_power_on;
+	pd->genpd.power_off = owl_sps_power_off;
+	pd->genpd.flags = pd->info->genpd_flags;
+	pm_genpd_init(&pd->genpd, NULL, false);
+
+	sps->genpd_data.domains[index] = &pd->genpd;
+
+	return 0;
+}
+
+static int owl_sps_probe(struct platform_device *pdev)
+{
+	const struct owl_sps_info *sps_info;
+	struct owl_sps *sps;
+	int i, ret;
+
+	sps_info = device_get_match_data(&pdev->dev);
+	if (!sps_info) {
+		dev_err(&pdev->dev, "unknown compatible or missing data\n");
+		return -EINVAL;
+	}
+
+	sps = devm_kzalloc(&pdev->dev,
+			   struct_size(sps, domains, sps_info->num_domains),
+			   GFP_KERNEL);
+	if (!sps)
+		return -ENOMEM;
+
+	sps->base = of_io_request_and_map(pdev->dev.of_node, 0, "owl-sps");
+	if (IS_ERR(sps->base)) {
+		dev_err(&pdev->dev, "failed to map sps registers\n");
+		return PTR_ERR(sps->base);
+	}
+
+	sps->dev = &pdev->dev;
+	sps->info = sps_info;
+	sps->genpd_data.domains = sps->domains;
+	sps->genpd_data.num_domains = sps_info->num_domains;
+
+	for (i = 0; i < sps_info->num_domains; i++) {
+		ret = owl_sps_init_domain(sps, i);
+		if (ret)
+			return ret;
+	}
+
+	ret = of_genpd_add_provider_onecell(pdev->dev.of_node, &sps->genpd_data);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add provider (%d)", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct owl_sps_domain_info s500_sps_domains[] = {
+	[S500_PD_VDE] = {
+		.name = "VDE",
+		.pwr_bit = 0,
+		.ack_bit = 16,
+	},
+	[S500_PD_VCE_SI] = {
+		.name = "VCE_SI",
+		.pwr_bit = 1,
+		.ack_bit = 17,
+	},
+	[S500_PD_USB2_1] = {
+		.name = "USB2_1",
+		.pwr_bit = 2,
+		.ack_bit = 18,
+	},
+	[S500_PD_CPU2] = {
+		.name = "CPU2",
+		.pwr_bit = 5,
+		.ack_bit = 21,
+		.genpd_flags = GENPD_FLAG_ALWAYS_ON,
+	},
+	[S500_PD_CPU3] = {
+		.name = "CPU3",
+		.pwr_bit = 6,
+		.ack_bit = 22,
+		.genpd_flags = GENPD_FLAG_ALWAYS_ON,
+	},
+	[S500_PD_DMA] = {
+		.name = "DMA",
+		.pwr_bit = 8,
+		.ack_bit = 12,
+	},
+	[S500_PD_DS] = {
+		.name = "DS",
+		.pwr_bit = 9,
+		.ack_bit = 13,
+	},
+	[S500_PD_USB3] = {
+		.name = "USB3",
+		.pwr_bit = 10,
+		.ack_bit = 14,
+	},
+	[S500_PD_USB2_0] = {
+		.name = "USB2_0",
+		.pwr_bit = 11,
+		.ack_bit = 15,
+	},
+};
+
+static const struct owl_sps_info s500_sps_info = {
+	.num_domains = ARRAY_SIZE(s500_sps_domains),
+	.domains = s500_sps_domains,
+};
+
+static const struct owl_sps_domain_info s700_sps_domains[] = {
+	[S700_PD_VDE] = {
+		.name = "VDE",
+		.pwr_bit = 0,
+	},
+	[S700_PD_VCE_SI] = {
+		.name = "VCE_SI",
+		.pwr_bit = 1,
+	},
+	[S700_PD_USB2_1] = {
+		.name = "USB2_1",
+		.pwr_bit = 2,
+	},
+	[S700_PD_HDE] = {
+		.name = "HDE",
+		.pwr_bit = 7,
+	},
+	[S700_PD_DMA] = {
+		.name = "DMA",
+		.pwr_bit = 8,
+	},
+	[S700_PD_DS] = {
+		.name = "DS",
+		.pwr_bit = 9,
+	},
+	[S700_PD_USB3] = {
+		.name = "USB3",
+		.pwr_bit = 10,
+	},
+	[S700_PD_USB2_0] = {
+		.name = "USB2_0",
+		.pwr_bit = 11,
+	},
+};
+
+static const struct owl_sps_info s700_sps_info = {
+	.num_domains = ARRAY_SIZE(s700_sps_domains),
+	.domains = s700_sps_domains,
+};
+
+static const struct owl_sps_domain_info s900_sps_domains[] = {
+	[S900_PD_GPU_B] = {
+		.name = "GPU_B",
+		.pwr_bit = 3,
+	},
+	[S900_PD_VCE] = {
+		.name = "VCE",
+		.pwr_bit = 4,
+	},
+	[S900_PD_SENSOR] = {
+		.name = "SENSOR",
+		.pwr_bit = 5,
+	},
+	[S900_PD_VDE] = {
+		.name = "VDE",
+		.pwr_bit = 6,
+	},
+	[S900_PD_HDE] = {
+		.name = "HDE",
+		.pwr_bit = 7,
+	},
+	[S900_PD_USB3] = {
+		.name = "USB3",
+		.pwr_bit = 8,
+	},
+	[S900_PD_DDR0] = {
+		.name = "DDR0",
+		.pwr_bit = 9,
+	},
+	[S900_PD_DDR1] = {
+		.name = "DDR1",
+		.pwr_bit = 10,
+	},
+	[S900_PD_DE] = {
+		.name = "DE",
+		.pwr_bit = 13,
+	},
+	[S900_PD_NAND] = {
+		.name = "NAND",
+		.pwr_bit = 14,
+	},
+	[S900_PD_USB2_H0] = {
+		.name = "USB2_H0",
+		.pwr_bit = 15,
+	},
+	[S900_PD_USB2_H1] = {
+		.name = "USB2_H1",
+		.pwr_bit = 16,
+	},
+};
+
+static const struct owl_sps_info s900_sps_info = {
+	.num_domains = ARRAY_SIZE(s900_sps_domains),
+	.domains = s900_sps_domains,
+};
+
+static const struct of_device_id owl_sps_of_matches[] = {
+	{ .compatible = "actions,s500-sps", .data = &s500_sps_info },
+	{ .compatible = "actions,s700-sps", .data = &s700_sps_info },
+	{ .compatible = "actions,s900-sps", .data = &s900_sps_info },
+	{ }
+};
+
+static struct platform_driver owl_sps_platform_driver = {
+	.probe = owl_sps_probe,
+	.driver = {
+		.name = "owl-sps",
+		.of_match_table = owl_sps_of_matches,
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init owl_sps_init(void)
+{
+	return platform_driver_register(&owl_sps_platform_driver);
+}
+postcore_initcall(owl_sps_init);