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, 89 insertions, 0 deletions

diff --git a/drivers/ps3/vuart.h b/drivers/ps3/vuart.h
new file mode 100644
index 000000000..64d34efef
--- /dev/null
+++ b/drivers/ps3/vuart.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  PS3 virtual uart
+ *
+ *  Copyright (C) 2006 Sony Computer Entertainment Inc.
+ *  Copyright 2006 Sony Corp.
+ */
+
+#if !defined(_PS3_VUART_H)
+#define _PS3_VUART_H
+
+#include <asm/ps3.h>
+
+struct ps3_vuart_stats {
+	unsigned long bytes_written;
+	unsigned long bytes_read;
+	unsigned long tx_interrupts;
+	unsigned long rx_interrupts;
+	unsigned long disconnect_interrupts;
+};
+
+struct ps3_vuart_work {
+	struct work_struct work;
+	unsigned long trigger;
+	struct ps3_system_bus_device *dev; /* to convert work to device */
+};
+
+/**
+ * struct ps3_vuart_port_driver - a driver for a device on a vuart port
+ */
+
+struct ps3_vuart_port_driver {
+	struct ps3_system_bus_driver core;
+	int (*probe)(struct ps3_system_bus_device *);
+	int (*remove)(struct ps3_system_bus_device *);
+	void (*shutdown)(struct ps3_system_bus_device *);
+	void (*work)(struct ps3_system_bus_device *);
+	/* int (*tx_event)(struct ps3_system_bus_device *dev); */
+	/* int (*rx_event)(struct ps3_system_bus_device *dev); */
+	/* int (*disconnect_event)(struct ps3_system_bus_device *dev); */
+	/* int (*suspend)(struct ps3_system_bus_device *, pm_message_t); */
+	/* int (*resume)(struct ps3_system_bus_device *); */
+};
+
+int ps3_vuart_port_driver_register(struct ps3_vuart_port_driver *drv);
+void ps3_vuart_port_driver_unregister(struct ps3_vuart_port_driver *drv);
+
+static inline struct ps3_vuart_port_driver *
+	ps3_system_bus_dev_to_vuart_drv(struct ps3_system_bus_device *_dev)
+{
+	struct ps3_system_bus_driver *sbd =
+		ps3_system_bus_dev_to_system_bus_drv(_dev);
+	BUG_ON(!sbd);
+	return container_of(sbd, struct ps3_vuart_port_driver, core);
+}
+static inline struct ps3_system_bus_device *ps3_vuart_work_to_system_bus_dev(
+	struct work_struct *_work)
+{
+	struct ps3_vuart_work *vw = container_of(_work, struct ps3_vuart_work,
+		work);
+	return vw->dev;
+}
+
+int ps3_vuart_write(struct ps3_system_bus_device *dev, const void *buf,
+	unsigned int bytes);
+int ps3_vuart_read(struct ps3_system_bus_device *dev, void *buf,
+	unsigned int bytes);
+int ps3_vuart_read_async(struct ps3_system_bus_device *dev, unsigned int bytes);
+void ps3_vuart_cancel_async(struct ps3_system_bus_device *dev);
+void ps3_vuart_clear_rx_bytes(struct ps3_system_bus_device *dev,
+	unsigned int bytes);
+
+struct vuart_triggers {
+	unsigned long rx;
+	unsigned long tx;
+};
+
+int ps3_vuart_get_triggers(struct ps3_system_bus_device *dev,
+	struct vuart_triggers *trig);
+int ps3_vuart_set_triggers(struct ps3_system_bus_device *dev, unsigned int tx,
+	unsigned int rx);
+int ps3_vuart_enable_interrupt_tx(struct ps3_system_bus_device *dev);
+int ps3_vuart_disable_interrupt_tx(struct ps3_system_bus_device *dev);
+int ps3_vuart_enable_interrupt_rx(struct ps3_system_bus_device *dev);
+int ps3_vuart_disable_interrupt_rx(struct ps3_system_bus_device *dev);
+int ps3_vuart_enable_interrupt_disconnect(struct ps3_system_bus_device *dev);
+int ps3_vuart_disable_interrupt_disconnect(struct ps3_system_bus_device *dev);
+
+#endif