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, 135 insertions, 0 deletions

diff --git a/drivers/input/misc/e3x0-button.c b/drivers/input/misc/e3x0-button.c
new file mode 100644
index 000000000..5bd527117
--- /dev/null
+++ b/drivers/input/misc/e3x0-button.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2014, National Instruments Corp. All rights reserved.
+ *
+ * Driver for NI Ettus Research USRP E3x0 Button Driver
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+static irqreturn_t e3x0_button_release_handler(int irq, void *data)
+{
+	struct input_dev *idev = data;
+
+	input_report_key(idev, KEY_POWER, 0);
+	input_sync(idev);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t e3x0_button_press_handler(int irq, void *data)
+{
+	struct input_dev *idev = data;
+
+	input_report_key(idev, KEY_POWER, 1);
+	pm_wakeup_event(idev->dev.parent, 0);
+	input_sync(idev);
+
+	return IRQ_HANDLED;
+}
+
+static int e3x0_button_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(platform_get_irq_byname(pdev, "press"));
+
+	return 0;
+}
+
+static int e3x0_button_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(platform_get_irq_byname(pdev, "press"));
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(e3x0_button_pm_ops,
+				e3x0_button_suspend, e3x0_button_resume);
+
+static int e3x0_button_probe(struct platform_device *pdev)
+{
+	struct input_dev *input;
+	int irq_press, irq_release;
+	int error;
+
+	irq_press = platform_get_irq_byname(pdev, "press");
+	if (irq_press < 0)
+		return irq_press;
+
+	irq_release = platform_get_irq_byname(pdev, "release");
+	if (irq_release < 0)
+		return irq_release;
+
+	input = devm_input_allocate_device(&pdev->dev);
+	if (!input)
+		return -ENOMEM;
+
+	input->name = "NI Ettus Research USRP E3x0 Button Driver";
+	input->phys = "e3x0_button/input0";
+	input->dev.parent = &pdev->dev;
+
+	input_set_capability(input, EV_KEY, KEY_POWER);
+
+	error = devm_request_irq(&pdev->dev, irq_press,
+				 e3x0_button_press_handler, 0,
+				 "e3x0-button", input);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to request 'press' IRQ#%d: %d\n",
+			irq_press, error);
+		return error;
+	}
+
+	error = devm_request_irq(&pdev->dev, irq_release,
+				 e3x0_button_release_handler, 0,
+				 "e3x0-button", input);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to request 'release' IRQ#%d: %d\n",
+			irq_release, error);
+		return error;
+	}
+
+	error = input_register_device(input);
+	if (error) {
+		dev_err(&pdev->dev, "Can't register input device: %d\n", error);
+		return error;
+	}
+
+	device_init_wakeup(&pdev->dev, 1);
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id e3x0_button_match[] = {
+	{ .compatible = "ettus,e3x0-button", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, e3x0_button_match);
+#endif
+
+static struct platform_driver e3x0_button_driver = {
+	.driver		= {
+		.name	= "e3x0-button",
+		.of_match_table = of_match_ptr(e3x0_button_match),
+		.pm	= pm_sleep_ptr(&e3x0_button_pm_ops),
+	},
+	.probe		= e3x0_button_probe,
+};
+
+module_platform_driver(e3x0_button_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
+MODULE_DESCRIPTION("NI Ettus Research USRP E3x0 Button driver");
+MODULE_ALIAS("platform:e3x0-button");