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>

1 files changed, 338 insertions, 0 deletions

diff --git a/drivers/phy/broadcom/phy-bcm-sr-usb.c b/drivers/phy/broadcom/phy-bcm-sr-usb.c
new file mode 100644
index 000000000..6bcfe8360
--- /dev/null
+++ b/drivers/phy/broadcom/phy-bcm-sr-usb.c
@@ -0,0 +1,338 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016-2018 Broadcom
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+
+enum bcm_usb_phy_version {
+	BCM_SR_USB_COMBO_PHY,
+	BCM_SR_USB_HS_PHY,
+};
+
+enum bcm_usb_phy_reg {
+	PLL_CTRL,
+	PHY_CTRL,
+	PHY_PLL_CTRL,
+};
+
+/* USB PHY registers */
+
+static const u8 bcm_usb_combo_phy_ss[] = {
+	[PLL_CTRL]		= 0x18,
+	[PHY_CTRL]		= 0x14,
+};
+
+static const u8 bcm_usb_combo_phy_hs[] = {
+	[PLL_CTRL]	= 0x0c,
+	[PHY_CTRL]	= 0x10,
+};
+
+static const u8 bcm_usb_hs_phy[] = {
+	[PLL_CTRL]	= 0x8,
+	[PHY_CTRL]	= 0xc,
+};
+
+enum pll_ctrl_bits {
+	PLL_RESETB,
+	SSPLL_SUSPEND_EN,
+	PLL_SEQ_START,
+	PLL_LOCK,
+};
+
+static const u8 u3pll_ctrl[] = {
+	[PLL_RESETB]		= 0,
+	[SSPLL_SUSPEND_EN]	= 1,
+	[PLL_SEQ_START]		= 2,
+	[PLL_LOCK]		= 3,
+};
+
+#define HSPLL_PDIV_MASK		0xF
+#define HSPLL_PDIV_VAL		0x1
+
+static const u8 u2pll_ctrl[] = {
+	[PLL_RESETB]	= 5,
+	[PLL_LOCK]	= 6,
+};
+
+enum bcm_usb_phy_ctrl_bits {
+	CORERDY,
+	PHY_RESETB,
+	PHY_PCTL,
+};
+
+#define PHY_PCTL_MASK	0xffff
+#define SSPHY_PCTL_VAL	0x0006
+
+static const u8 u3phy_ctrl[] = {
+	[PHY_RESETB]	= 1,
+	[PHY_PCTL]	= 2,
+};
+
+static const u8 u2phy_ctrl[] = {
+	[CORERDY]		= 0,
+	[PHY_RESETB]		= 5,
+	[PHY_PCTL]		= 6,
+};
+
+struct bcm_usb_phy_cfg {
+	uint32_t type;
+	uint32_t version;
+	void __iomem *regs;
+	struct phy *phy;
+	const u8 *offset;
+};
+
+#define PLL_LOCK_RETRY_COUNT	1000
+
+enum bcm_usb_phy_type {
+	USB_HS_PHY,
+	USB_SS_PHY,
+};
+
+#define NUM_BCM_SR_USB_COMBO_PHYS	2
+
+static inline void bcm_usb_reg32_clrbits(void __iomem *addr, uint32_t clear)
+{
+	writel(readl(addr) & ~clear, addr);
+}
+
+static inline void bcm_usb_reg32_setbits(void __iomem *addr, uint32_t set)
+{
+	writel(readl(addr) | set, addr);
+}
+
+static int bcm_usb_pll_lock_check(void __iomem *addr, u32 bit)
+{
+	u32 data;
+	int ret;
+
+	ret = readl_poll_timeout_atomic(addr, data, (data & bit), 1,
+					PLL_LOCK_RETRY_COUNT);
+	if (ret)
+		pr_err("%s: FAIL\n", __func__);
+
+	return ret;
+}
+
+static int bcm_usb_ss_phy_init(struct bcm_usb_phy_cfg *phy_cfg)
+{
+	int ret = 0;
+	void __iomem *regs = phy_cfg->regs;
+	const u8 *offset;
+	u32 rd_data;
+
+	offset = phy_cfg->offset;
+
+	/* Set pctl with mode and soft reset */
+	rd_data = readl(regs + offset[PHY_CTRL]);
+	rd_data &= ~(PHY_PCTL_MASK << u3phy_ctrl[PHY_PCTL]);
+	rd_data |= (SSPHY_PCTL_VAL << u3phy_ctrl[PHY_PCTL]);
+	writel(rd_data, regs + offset[PHY_CTRL]);
+
+	bcm_usb_reg32_clrbits(regs + offset[PLL_CTRL],
+			      BIT(u3pll_ctrl[SSPLL_SUSPEND_EN]));
+	bcm_usb_reg32_setbits(regs + offset[PLL_CTRL],
+			      BIT(u3pll_ctrl[PLL_SEQ_START]));
+	bcm_usb_reg32_setbits(regs + offset[PLL_CTRL],
+			      BIT(u3pll_ctrl[PLL_RESETB]));
+
+	/* Maximum timeout for PLL reset done */
+	msleep(30);
+
+	ret = bcm_usb_pll_lock_check(regs + offset[PLL_CTRL],
+				     BIT(u3pll_ctrl[PLL_LOCK]));
+
+	return ret;
+}
+
+static int bcm_usb_hs_phy_init(struct bcm_usb_phy_cfg *phy_cfg)
+{
+	int ret = 0;
+	void __iomem *regs = phy_cfg->regs;
+	const u8 *offset;
+
+	offset = phy_cfg->offset;
+
+	bcm_usb_reg32_clrbits(regs + offset[PLL_CTRL],
+			      BIT(u2pll_ctrl[PLL_RESETB]));
+	bcm_usb_reg32_setbits(regs + offset[PLL_CTRL],
+			      BIT(u2pll_ctrl[PLL_RESETB]));
+
+	ret = bcm_usb_pll_lock_check(regs + offset[PLL_CTRL],
+				     BIT(u2pll_ctrl[PLL_LOCK]));
+
+	return ret;
+}
+
+static int bcm_usb_phy_reset(struct phy *phy)
+{
+	struct bcm_usb_phy_cfg *phy_cfg = phy_get_drvdata(phy);
+	void __iomem *regs = phy_cfg->regs;
+	const u8 *offset;
+
+	offset = phy_cfg->offset;
+
+	if (phy_cfg->type == USB_HS_PHY) {
+		bcm_usb_reg32_clrbits(regs + offset[PHY_CTRL],
+				      BIT(u2phy_ctrl[CORERDY]));
+		bcm_usb_reg32_setbits(regs + offset[PHY_CTRL],
+				      BIT(u2phy_ctrl[CORERDY]));
+	}
+
+	return 0;
+}
+
+static int bcm_usb_phy_init(struct phy *phy)
+{
+	struct bcm_usb_phy_cfg *phy_cfg = phy_get_drvdata(phy);
+	int ret = -EINVAL;
+
+	if (phy_cfg->type == USB_SS_PHY)
+		ret = bcm_usb_ss_phy_init(phy_cfg);
+	else if (phy_cfg->type == USB_HS_PHY)
+		ret = bcm_usb_hs_phy_init(phy_cfg);
+
+	return ret;
+}
+
+static const struct phy_ops sr_phy_ops = {
+	.init		= bcm_usb_phy_init,
+	.reset		= bcm_usb_phy_reset,
+	.owner		= THIS_MODULE,
+};
+
+static struct phy *bcm_usb_phy_xlate(struct device *dev,
+				     const struct of_phandle_args *args)
+{
+	struct bcm_usb_phy_cfg *phy_cfg;
+	int phy_idx;
+
+	phy_cfg = dev_get_drvdata(dev);
+	if (!phy_cfg)
+		return ERR_PTR(-EINVAL);
+
+	if (phy_cfg->version == BCM_SR_USB_COMBO_PHY) {
+		phy_idx = args->args[0];
+
+		if (WARN_ON(phy_idx > 1))
+			return ERR_PTR(-ENODEV);
+
+		return phy_cfg[phy_idx].phy;
+	} else
+		return phy_cfg->phy;
+}
+
+static int bcm_usb_phy_create(struct device *dev, struct device_node *node,
+			      void __iomem *regs, uint32_t version)
+{
+	struct bcm_usb_phy_cfg *phy_cfg;
+	int idx;
+
+	if (version == BCM_SR_USB_COMBO_PHY) {
+		phy_cfg = devm_kzalloc(dev, NUM_BCM_SR_USB_COMBO_PHYS *
+				       sizeof(struct bcm_usb_phy_cfg),
+				       GFP_KERNEL);
+		if (!phy_cfg)
+			return -ENOMEM;
+
+		for (idx = 0; idx < NUM_BCM_SR_USB_COMBO_PHYS; idx++) {
+			phy_cfg[idx].regs = regs;
+			phy_cfg[idx].version = version;
+			if (idx == 0) {
+				phy_cfg[idx].offset = bcm_usb_combo_phy_hs;
+				phy_cfg[idx].type = USB_HS_PHY;
+			} else {
+				phy_cfg[idx].offset = bcm_usb_combo_phy_ss;
+				phy_cfg[idx].type = USB_SS_PHY;
+			}
+			phy_cfg[idx].phy = devm_phy_create(dev, node,
+							   &sr_phy_ops);
+			if (IS_ERR(phy_cfg[idx].phy))
+				return PTR_ERR(phy_cfg[idx].phy);
+
+			phy_set_drvdata(phy_cfg[idx].phy, &phy_cfg[idx]);
+		}
+	} else if (version == BCM_SR_USB_HS_PHY) {
+		phy_cfg = devm_kzalloc(dev, sizeof(struct bcm_usb_phy_cfg),
+				       GFP_KERNEL);
+		if (!phy_cfg)
+			return -ENOMEM;
+
+		phy_cfg->regs = regs;
+		phy_cfg->version = version;
+		phy_cfg->offset = bcm_usb_hs_phy;
+		phy_cfg->type = USB_HS_PHY;
+		phy_cfg->phy = devm_phy_create(dev, node, &sr_phy_ops);
+		if (IS_ERR(phy_cfg->phy))
+			return PTR_ERR(phy_cfg->phy);
+
+		phy_set_drvdata(phy_cfg->phy, phy_cfg);
+	} else
+		return -ENODEV;
+
+	dev_set_drvdata(dev, phy_cfg);
+
+	return 0;
+}
+
+static const struct of_device_id bcm_usb_phy_of_match[] = {
+	{
+		.compatible = "brcm,sr-usb-combo-phy",
+		.data = (void *)BCM_SR_USB_COMBO_PHY,
+	},
+	{
+		.compatible = "brcm,sr-usb-hs-phy",
+		.data = (void *)BCM_SR_USB_HS_PHY,
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, bcm_usb_phy_of_match);
+
+static int bcm_usb_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *dn = dev->of_node;
+	const struct of_device_id *of_id;
+	void __iomem *regs;
+	int ret;
+	enum bcm_usb_phy_version version;
+	struct phy_provider *phy_provider;
+
+	regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	of_id = of_match_node(bcm_usb_phy_of_match, dn);
+	if (of_id)
+		version = (uintptr_t)of_id->data;
+	else
+		return -ENODEV;
+
+	ret = bcm_usb_phy_create(dev, dn, regs, version);
+	if (ret)
+		return ret;
+
+	phy_provider = devm_of_phy_provider_register(dev, bcm_usb_phy_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static struct platform_driver bcm_usb_phy_driver = {
+	.driver = {
+		.name = "phy-bcm-sr-usb",
+		.of_match_table = bcm_usb_phy_of_match,
+	},
+	.probe = bcm_usb_phy_probe,
+};
+module_platform_driver(bcm_usb_phy_driver);
+
+MODULE_AUTHOR("Broadcom");
+MODULE_DESCRIPTION("Broadcom stingray USB Phy driver");
+MODULE_LICENSE("GPL v2");