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, 53 insertions, 0 deletions

diff --git a/drivers/siox/siox.h b/drivers/siox/siox.h
new file mode 100644
index 000000000..513f2c831
--- /dev/null
+++ b/drivers/siox/siox.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2015-2017 Pengutronix, Uwe Kleine-König <kernel@pengutronix.de>
+ */
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/siox.h>
+
+#define to_siox_master(_dev)	container_of((_dev), struct siox_master, dev)
+struct siox_master {
+	/* these fields should be initialized by the driver */
+	int busno;
+	int (*pushpull)(struct siox_master *smaster,
+			size_t setbuf_len, const u8 setbuf[],
+			size_t getbuf_len, u8 getbuf[]);
+
+	/* might be initialized by the driver, if 0 it is set to HZ / 40 */
+	unsigned long poll_interval; /* in jiffies */
+
+	/* framework private stuff */
+	struct mutex lock;
+	bool active;
+	struct module *owner;
+	struct device dev;
+	unsigned int num_devices;
+	struct list_head devices;
+
+	size_t setbuf_len, getbuf_len;
+	size_t buf_len;
+	u8 *buf;
+	u8 status;
+
+	unsigned long last_poll;
+	struct task_struct *poll_thread;
+};
+
+static inline void *siox_master_get_devdata(struct siox_master *smaster)
+{
+	return dev_get_drvdata(&smaster->dev);
+}
+
+struct siox_master *siox_master_alloc(struct device *dev, size_t size);
+static inline void siox_master_put(struct siox_master *smaster)
+{
+	put_device(&smaster->dev);
+}
+
+struct siox_master *devm_siox_master_alloc(struct device *dev, size_t size);
+
+int siox_master_register(struct siox_master *smaster);
+void siox_master_unregister(struct siox_master *smaster);
+
+int devm_siox_master_register(struct device *dev, struct siox_master *smaster);