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, 43 insertions, 0 deletions

diff --git a/arch/mips/dec/reset.c b/arch/mips/dec/reset.c
new file mode 100644
index 000000000..ee1ad38f4
--- /dev/null
+++ b/arch/mips/dec/reset.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Reset a DECstation machine.
+ *
+ * Copyright (C) 199x  the Anonymous
+ * Copyright (C) 2001, 2002, 2003  Maciej W. Rozycki
+ */
+#include <linux/interrupt.h>
+#include <linux/linkage.h>
+
+#include <asm/addrspace.h>
+
+#include <asm/dec/reset.h>
+
+typedef void __noreturn (* noret_func_t)(void);
+
+static inline void __noreturn back_to_prom(void)
+{
+	noret_func_t func = (void *)CKSEG1ADDR(0x1fc00000);
+
+	func();
+}
+
+void __noreturn dec_machine_restart(char *command)
+{
+	back_to_prom();
+}
+
+void __noreturn dec_machine_halt(void)
+{
+	back_to_prom();
+}
+
+void __noreturn dec_machine_power_off(void)
+{
+    /* DECstations don't have a software power switch */
+	back_to_prom();
+}
+
+irqreturn_t dec_intr_halt(int irq, void *dev_id)
+{
+	dec_machine_halt();
+}