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, 222 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/ts4800-ts.c b/drivers/input/touchscreen/ts4800-ts.c
new file mode 100644
index 000000000..98422d1e8
--- /dev/null
+++ b/drivers/input/touchscreen/ts4800-ts.c
@@ -0,0 +1,222 @@
+/*
+ * Touchscreen driver for the TS-4800 board
+ *
+ * Copyright (c) 2015 - Savoir-faire Linux
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/bitops.h>
+#include <linux/input.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* polling interval in ms */
+#define POLL_INTERVAL		3
+
+#define DEBOUNCE_COUNT		1
+
+/* sensor values are 12-bit wide */
+#define MAX_12BIT		((1 << 12) - 1)
+
+#define PENDOWN_MASK		0x1
+
+#define X_OFFSET		0x0
+#define Y_OFFSET		0x2
+
+struct ts4800_ts {
+	struct input_dev        *input;
+	struct device           *dev;
+	char                    phys[32];
+
+	void __iomem            *base;
+	struct regmap           *regmap;
+	unsigned int            reg;
+	unsigned int            bit;
+
+	bool                    pendown;
+	int                     debounce;
+};
+
+static int ts4800_ts_open(struct input_dev *input_dev)
+{
+	struct ts4800_ts *ts = input_get_drvdata(input_dev);
+	int error;
+
+	ts->pendown = false;
+	ts->debounce = DEBOUNCE_COUNT;
+
+	error = regmap_update_bits(ts->regmap, ts->reg, ts->bit, ts->bit);
+	if (error) {
+		dev_warn(ts->dev, "Failed to enable touchscreen: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static void ts4800_ts_close(struct input_dev *input_dev)
+{
+	struct ts4800_ts *ts = input_get_drvdata(input_dev);
+	int ret;
+
+	ret = regmap_update_bits(ts->regmap, ts->reg, ts->bit, 0);
+	if (ret)
+		dev_warn(ts->dev, "Failed to disable touchscreen\n");
+
+}
+
+static void ts4800_ts_poll(struct input_dev *input_dev)
+{
+	struct ts4800_ts *ts = input_get_drvdata(input_dev);
+	u16 last_x = readw(ts->base + X_OFFSET);
+	u16 last_y = readw(ts->base + Y_OFFSET);
+	bool pendown = last_x & PENDOWN_MASK;
+
+	if (pendown) {
+		if (ts->debounce) {
+			ts->debounce--;
+			return;
+		}
+
+		if (!ts->pendown) {
+			input_report_key(input_dev, BTN_TOUCH, 1);
+			ts->pendown = true;
+		}
+
+		last_x = ((~last_x) >> 4) & MAX_12BIT;
+		last_y = ((~last_y) >> 4) & MAX_12BIT;
+
+		input_report_abs(input_dev, ABS_X, last_x);
+		input_report_abs(input_dev, ABS_Y, last_y);
+		input_sync(input_dev);
+	} else if (ts->pendown) {
+		ts->pendown = false;
+		ts->debounce = DEBOUNCE_COUNT;
+		input_report_key(input_dev, BTN_TOUCH, 0);
+		input_sync(input_dev);
+	}
+}
+
+static int ts4800_parse_dt(struct platform_device *pdev,
+			   struct ts4800_ts *ts)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	u32 reg, bit;
+	int error;
+
+	struct device_node *syscon_np __free(device_node) =
+		of_parse_phandle(np, "syscon", 0);
+	if (!syscon_np) {
+		dev_err(dev, "no syscon property\n");
+		return -ENODEV;
+	}
+
+	ts->regmap = syscon_node_to_regmap(syscon_np);
+	if (IS_ERR(ts->regmap)) {
+		dev_err(dev, "cannot get parent's regmap\n");
+		return PTR_ERR(ts->regmap);
+	}
+
+	error = of_property_read_u32_index(np, "syscon", 1, &reg);
+	if (error < 0) {
+		dev_err(dev, "no offset in syscon\n");
+		return error;
+	}
+
+	ts->reg = reg;
+
+	error = of_property_read_u32_index(np, "syscon", 2, &bit);
+	if (error < 0) {
+		dev_err(dev, "no bit in syscon\n");
+		return error;
+	}
+
+	ts->bit = BIT(bit);
+
+	return 0;
+}
+
+static int ts4800_ts_probe(struct platform_device *pdev)
+{
+	struct input_dev *input_dev;
+	struct ts4800_ts *ts;
+	int error;
+
+	ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	error = ts4800_parse_dt(pdev, ts);
+	if (error)
+		return error;
+
+	ts->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ts->base))
+		return PTR_ERR(ts->base);
+
+	input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!input_dev)
+		return -ENOMEM;
+
+	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&pdev->dev));
+	ts->input = input_dev;
+	ts->dev = &pdev->dev;
+
+	input_set_drvdata(input_dev, ts);
+
+	input_dev->name = "TS-4800 Touchscreen";
+	input_dev->phys = ts->phys;
+
+	input_dev->open = ts4800_ts_open;
+	input_dev->close = ts4800_ts_close;
+
+	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
+	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
+
+	error = input_setup_polling(input_dev, ts4800_ts_poll);
+	if (error) {
+		dev_err(&pdev->dev, "Unable to set up polling: %d\n", error);
+		return error;
+	}
+
+	input_set_poll_interval(input_dev, POLL_INTERVAL);
+
+	error = input_register_device(input_dev);
+	if (error) {
+		dev_err(&pdev->dev,
+			"Unable to register input device: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id ts4800_ts_of_match[] = {
+	{ .compatible = "technologic,ts4800-ts", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ts4800_ts_of_match);
+
+static struct platform_driver ts4800_ts_driver = {
+	.driver = {
+		.name = "ts4800-ts",
+		.of_match_table = ts4800_ts_of_match,
+	},
+	.probe = ts4800_ts_probe,
+};
+module_platform_driver(ts4800_ts_driver);
+
+MODULE_AUTHOR("Damien Riegel <damien.riegel@savoirfairelinux.com>");
+MODULE_DESCRIPTION("TS-4800 Touchscreen Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:ts4800_ts");