Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted

Changes:

Make expedited grace periods expedite normal RCU callbacks

Miscellaneous fixes:
 * Improve diagnostic output with character task states.
 * Mark accesses to inform KCSAN of concurrency design.
 * Move from kmalloc() to kmalloc_obj().
 * Documentation updates.
 * Improve handling of RCU deferred quiescent states.
 * Clean up unused function arguments and structure fields.
 * Reduce show_rcu_gp_kthreads() stack space.

Tasks RCU updates:
 * Clean up after SRCU re-implementation of Tasks Trace RCU.
 * Mark accesses to inform KCSAN of concurrency design.
 * Add ->lazy_timer status to diagnostic output.
 * Remove an unnecessary memory barrier.
 * Fix a data race, courtesy of KCSAN.
 * Documentation updates.
 * Convert cond_resched_tasks_rcu_qs() from macro to static inline
   function.

SRCU updates:
 * Add Rust helpers for SRCU.
 * Avoid losing queued work at cleanup_srcu_struct() time.

Torture-test updates:
 * Preparation work for immediate RCU priority deboosting.
 * Test RCU readers from real interrupt handlers (as opposed to softirq).
 * Simplify code through use of cpumask_next_wrap().
 * Improve diagnostic output with character task states.
 * Add rcutorture.nwriters parameter to allow lightweight stall testing,
   and rcutorture.stall_only to make doing so easier.
 * Test an RCU Tasks Trace grace period implying an RCU grace period.
 * Make RCU Tasks Trace torturing track reader batches.
 * Fix a data race, courtesy of KCSAN.
 * Plug a shuffle_tmp_mask memory leak on kthread spawn failure.

1 files changed, 163 insertions, 0 deletions

diff --git a/drivers/usb/phy/phy-isp1301.c b/drivers/usb/phy/phy-isp1301.c
new file mode 100644
index 000000000..73cc70e95
--- /dev/null
+++ b/drivers/usb/phy/phy-isp1301.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NXP ISP1301 USB transceiver driver
+ *
+ * Copyright (C) 2012 Roland Stigge
+ *
+ * Author: Roland Stigge <stigge@antcom.de>
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/i2c.h>
+#include <linux/usb/phy.h>
+#include <linux/usb/isp1301.h>
+
+#define DRV_NAME		"isp1301"
+
+struct isp1301 {
+	struct usb_phy		phy;
+	struct mutex		mutex;
+
+	struct i2c_client	*client;
+};
+
+#define phy_to_isp(p)		(container_of((p), struct isp1301, phy))
+
+static const struct i2c_device_id isp1301_id[] = {
+	{ .name = "isp1301" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, isp1301_id);
+
+static const struct of_device_id isp1301_of_match[] = {
+	{.compatible = "nxp,isp1301" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, isp1301_of_match);
+
+static struct i2c_client *isp1301_i2c_client;
+
+static int __isp1301_write(struct isp1301 *isp, u8 reg, u8 value, u8 clear)
+{
+	return i2c_smbus_write_byte_data(isp->client, reg | clear, value);
+}
+
+static int isp1301_write(struct isp1301 *isp, u8 reg, u8 value)
+{
+	return __isp1301_write(isp, reg, value, 0);
+}
+
+static int isp1301_clear(struct isp1301 *isp, u8 reg, u8 value)
+{
+	return __isp1301_write(isp, reg, value, ISP1301_I2C_REG_CLEAR_ADDR);
+}
+
+static int isp1301_phy_init(struct usb_phy *phy)
+{
+	struct isp1301 *isp = phy_to_isp(phy);
+
+	/* Disable transparent UART mode first */
+	isp1301_clear(isp, ISP1301_I2C_MODE_CONTROL_1, MC1_UART_EN);
+	isp1301_clear(isp, ISP1301_I2C_MODE_CONTROL_1, ~MC1_SPEED_REG);
+	isp1301_write(isp, ISP1301_I2C_MODE_CONTROL_1, MC1_SPEED_REG);
+	isp1301_clear(isp, ISP1301_I2C_MODE_CONTROL_2, ~0);
+	isp1301_write(isp, ISP1301_I2C_MODE_CONTROL_2, (MC2_BI_DI | MC2_PSW_EN
+				| MC2_SPD_SUSP_CTRL));
+
+	isp1301_clear(isp, ISP1301_I2C_OTG_CONTROL_1, ~0);
+	isp1301_write(isp, ISP1301_I2C_MODE_CONTROL_1, MC1_DAT_SE0);
+	isp1301_write(isp, ISP1301_I2C_OTG_CONTROL_1, (OTG1_DM_PULLDOWN
+				| OTG1_DP_PULLDOWN));
+	isp1301_clear(isp, ISP1301_I2C_OTG_CONTROL_1, (OTG1_DM_PULLUP
+				| OTG1_DP_PULLUP));
+
+	/* mask all interrupts */
+	isp1301_clear(isp, ISP1301_I2C_INTERRUPT_LATCH, ~0);
+	isp1301_clear(isp, ISP1301_I2C_INTERRUPT_FALLING, ~0);
+	isp1301_clear(isp, ISP1301_I2C_INTERRUPT_RISING, ~0);
+
+	return 0;
+}
+
+static int isp1301_phy_set_vbus(struct usb_phy *phy, int on)
+{
+	struct isp1301 *isp = phy_to_isp(phy);
+
+	if (on)
+		isp1301_write(isp, ISP1301_I2C_OTG_CONTROL_1, OTG1_VBUS_DRV);
+	else
+		isp1301_clear(isp, ISP1301_I2C_OTG_CONTROL_1, OTG1_VBUS_DRV);
+
+	return 0;
+}
+
+static int isp1301_probe(struct i2c_client *client)
+{
+	struct isp1301 *isp;
+	struct usb_phy *phy;
+
+	isp = devm_kzalloc(&client->dev, sizeof(*isp), GFP_KERNEL);
+	if (!isp)
+		return -ENOMEM;
+
+	isp->client = client;
+	mutex_init(&isp->mutex);
+
+	phy = &isp->phy;
+	phy->dev = &client->dev;
+	phy->label = DRV_NAME;
+	phy->init = isp1301_phy_init;
+	phy->set_vbus = isp1301_phy_set_vbus;
+	phy->type = USB_PHY_TYPE_USB2;
+
+	i2c_set_clientdata(client, isp);
+	usb_add_phy_dev(phy);
+
+	isp1301_i2c_client = client;
+
+	return 0;
+}
+
+static void isp1301_remove(struct i2c_client *client)
+{
+	struct isp1301 *isp = i2c_get_clientdata(client);
+
+	usb_remove_phy(&isp->phy);
+	isp1301_i2c_client = NULL;
+}
+
+static struct i2c_driver isp1301_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = isp1301_of_match,
+	},
+	.probe = isp1301_probe,
+	.remove = isp1301_remove,
+	.id_table = isp1301_id,
+};
+
+module_i2c_driver(isp1301_driver);
+
+struct i2c_client *isp1301_get_client(struct device_node *node)
+{
+	struct i2c_client *client;
+
+	/* reference of ISP1301 I2C node via DT */
+	client = of_find_i2c_device_by_node(node);
+	if (client)
+		return client;
+
+	/* non-DT: only one ISP1301 chip supported */
+	if (isp1301_i2c_client) {
+		get_device(&isp1301_i2c_client->dev);
+		return isp1301_i2c_client;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(isp1301_get_client);
+
+MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
+MODULE_DESCRIPTION("NXP ISP1301 USB transceiver driver");
+MODULE_LICENSE("GPL");