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, 41 insertions, 0 deletions

diff --git a/lib/raid/raid6/algos.h b/lib/raid/raid6/algos.h
new file mode 100644
index 000000000..43f636be1
--- /dev/null
+++ b/lib/raid/raid6/algos.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright 2003 H. Peter Anvin - All Rights Reserved
+ */
+#ifndef _PQ_IMPL_H
+#define _PQ_IMPL_H
+
+#include <linux/init.h>
+#include <linux/raid/pq_tables.h>
+
+/* Routine choices */
+struct raid6_calls {
+	const char *name;
+	void (*gen_syndrome)(int disks, size_t bytes, void **ptrs);
+	void (*xor_syndrome)(int disks, int start, int stop, size_t bytes,
+			void **ptrs);
+};
+
+struct raid6_recov_calls {
+	const char *name;
+	void (*data2)(int disks, size_t bytes, int faila, int failb,
+			void **ptrs);
+	void (*datap)(int disks, size_t bytes, int faila, void **ptrs);
+};
+
+void __init raid6_algo_add(const struct raid6_calls *algo);
+void __init raid6_algo_add_default(void);
+void __init raid6_recov_algo_add(const struct raid6_recov_calls *algo);
+
+/* for the kunit test */
+const struct raid6_calls *raid6_algo_find(unsigned int idx);
+const struct raid6_recov_calls *raid6_recov_algo_find(unsigned int idx);
+
+/* generic implementations */
+extern const struct raid6_calls raid6_intx1;
+extern const struct raid6_calls raid6_intx2;
+extern const struct raid6_calls raid6_intx4;
+extern const struct raid6_calls raid6_intx8;
+extern const struct raid6_recov_calls raid6_recov_intx1;
+
+#endif /* _PQ_IMPL_H */