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>

3 files changed, 190 insertions, 0 deletions

diff --git a/drivers/phy/sophgo/Kconfig b/drivers/phy/sophgo/Kconfig
new file mode 100644
index 000000000..2c943bbe1
--- /dev/null
+++ b/drivers/phy/sophgo/Kconfig
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Sophgo platforms
+#
+
+if ARCH_SOPHGO || COMPILE_TEST
+
+config PHY_SOPHGO_CV1800_USB2
+	tristate "Sophgo CV18XX/SG200X USB 2.0 PHY support"
+	depends on MFD_SYSCON
+	depends on USB_SUPPORT
+	select GENERIC_PHY
+	help
+	  Enable this to support the USB 2.0 PHY used with
+	  the DWC2 USB controller in Sophgo CV18XX/SG200X
+	  series SoC.
+	  If unsure, say N.
+
+endif # ARCH_SOPHGO || COMPILE_TEST
diff --git a/drivers/phy/sophgo/Makefile b/drivers/phy/sophgo/Makefile
new file mode 100644
index 000000000..318060661
--- /dev/null
+++ b/drivers/phy/sophgo/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_PHY_SOPHGO_CV1800_USB2)	+= phy-cv1800-usb2.o
diff --git a/drivers/phy/sophgo/phy-cv1800-usb2.c b/drivers/phy/sophgo/phy-cv1800-usb2.c
new file mode 100644
index 000000000..6fe846534
--- /dev/null
+++ b/drivers/phy/sophgo/phy-cv1800-usb2.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2025 Inochi Amaoto <inochiama@outlook.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/bitfield.h>
+#include <linux/debugfs.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+#include <linux/regmap.h>
+#include <linux/spinlock.h>
+
+#define REG_USB_PHY_CTRL		0x048
+
+#define PHY_VBUS_POWER_EN		BIT(0)
+#define PHY_VBUS_POWER			BIT(1)
+#define PHY_ID_OVERWRITE_EN		BIT(6)
+#define PHY_ID_OVERWRITE_MODE		BIT(7)
+#define PHY_ID_OVERWRITE_MODE_HOST	FIELD_PREP(BIT(7), 0)
+#define PHY_ID_OVERWRITE_MODE_DEVICE	FIELD_PREP(BIT(7), 1)
+
+#define PHY_APP_CLK_RATE		125000000
+#define PHY_LPM_CLK_RATE		12000000
+#define PHY_STB_CLK_RATE		333334
+
+struct cv1800_usb_phy {
+	struct phy	*phy;
+	struct regmap	*syscon;
+	spinlock_t	lock;
+	struct clk	*usb_app_clk;
+	struct clk	*usb_lpm_clk;
+	struct clk	*usb_stb_clk;
+	bool		support_otg;
+};
+
+static int cv1800_usb_phy_set_mode(struct phy *_phy,
+				   enum phy_mode mode, int submode)
+{
+	struct cv1800_usb_phy *phy = phy_get_drvdata(_phy);
+	unsigned int regval = 0;
+	int ret;
+
+	dev_info(&phy->phy->dev, "set mode %d", (int)mode);
+
+	switch (mode) {
+	case PHY_MODE_USB_DEVICE:
+		regval = PHY_ID_OVERWRITE_EN | PHY_ID_OVERWRITE_MODE_DEVICE;
+		regmap_clear_bits(phy->syscon, REG_USB_PHY_CTRL, PHY_VBUS_POWER);
+		break;
+	case PHY_MODE_USB_HOST:
+		regval = PHY_ID_OVERWRITE_EN | PHY_ID_OVERWRITE_MODE_HOST;
+		regmap_set_bits(phy->syscon, REG_USB_PHY_CTRL, PHY_VBUS_POWER);
+		break;
+	case PHY_MODE_USB_OTG:
+		if (!phy->support_otg)
+			return 0;
+
+		ret = regmap_read(phy->syscon, REG_USB_PHY_CTRL, &regval);
+		if (ret)
+			return ret;
+
+		regval = FIELD_GET(PHY_ID_OVERWRITE_MODE, regval);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return regmap_update_bits(phy->syscon, REG_USB_PHY_CTRL,
+				  PHY_ID_OVERWRITE_EN | PHY_ID_OVERWRITE_MODE,
+				  regval);
+}
+
+static int cv1800_usb_phy_set_clock(struct cv1800_usb_phy *phy)
+{
+	int ret;
+
+	ret = clk_set_rate(phy->usb_app_clk, PHY_APP_CLK_RATE);
+	if (ret)
+		return ret;
+
+	ret = clk_set_rate(phy->usb_lpm_clk, PHY_LPM_CLK_RATE);
+	if (ret)
+		return ret;
+
+	return clk_set_rate(phy->usb_stb_clk, PHY_STB_CLK_RATE);
+}
+
+static const struct phy_ops cv1800_usb_phy_ops = {
+	.set_mode	= cv1800_usb_phy_set_mode,
+	.owner		= THIS_MODULE,
+};
+
+static int cv1800_usb_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device *parent = dev->parent;
+	struct cv1800_usb_phy *phy;
+	struct phy_provider *phy_provider;
+	int ret;
+
+	if (!parent)
+		return -ENODEV;
+
+	phy = devm_kmalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->syscon = syscon_node_to_regmap(parent->of_node);
+	if (IS_ERR_OR_NULL(phy->syscon))
+		return -ENODEV;
+
+	phy->support_otg = false;
+
+	spin_lock_init(&phy->lock);
+
+	phy->usb_app_clk = devm_clk_get_enabled(dev, "app");
+	if (IS_ERR(phy->usb_app_clk))
+		return dev_err_probe(dev, PTR_ERR(phy->usb_app_clk),
+			"Failed to get app clock\n");
+
+	phy->usb_lpm_clk = devm_clk_get_enabled(dev, "lpm");
+	if (IS_ERR(phy->usb_lpm_clk))
+		return dev_err_probe(dev, PTR_ERR(phy->usb_lpm_clk),
+			"Failed to get lpm clock\n");
+
+	phy->usb_stb_clk = devm_clk_get_enabled(dev, "stb");
+	if (IS_ERR(phy->usb_stb_clk))
+		return dev_err_probe(dev, PTR_ERR(phy->usb_stb_clk),
+			"Failed to get stb clock\n");
+
+	phy->phy = devm_phy_create(dev, NULL, &cv1800_usb_phy_ops);
+	if (IS_ERR(phy->phy))
+		return dev_err_probe(dev, PTR_ERR(phy->phy),
+			"Failed to create phy\n");
+
+	ret = cv1800_usb_phy_set_clock(phy);
+	if (ret)
+		return ret;
+
+	phy_set_drvdata(phy->phy, phy);
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct of_device_id cv1800_usb_phy_ids[] = {
+	{ .compatible = "sophgo,cv1800b-usb2-phy" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, cv1800_usb_phy_ids);
+
+static struct platform_driver cv1800_usb_phy_driver = {
+	.probe = cv1800_usb_phy_probe,
+	.driver = {
+		.name = "cv1800-usb2-phy",
+		.of_match_table = cv1800_usb_phy_ids,
+	 },
+};
+module_platform_driver(cv1800_usb_phy_driver);
+
+MODULE_AUTHOR("Inochi Amaoto <inochiama@outlook.com>");
+MODULE_DESCRIPTION("CV1800/SG2000 SoC USB 2.0 PHY driver");
+MODULE_LICENSE("GPL");