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, 29 insertions, 0 deletions

diff --git a/arch/powerpc/boot/treeboot-ebony.c b/arch/powerpc/boot/treeboot-ebony.c
new file mode 100644
index 000000000..332e28659
--- /dev/null
+++ b/arch/powerpc/boot/treeboot-ebony.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Old U-boot compatibility for Ebony
+ *
+ * Author: David Gibson <david@gibson.dropbear.id.au>
+ *
+ * Copyright 2007 David Gibson, IBM Corporatio.
+ *   Based on cuboot-83xx.c, which is:
+ * Copyright (c) 2007 Freescale Semiconductor, Inc.
+ */
+
+#include "ops.h"
+#include "stdio.h"
+#include "44x.h"
+
+BSS_STACK(4096);
+
+#define OPENBIOS_MAC_BASE	0xfffffe0c
+#define OPENBIOS_MAC_OFFSET	0xc
+
+void platform_init(void)
+{
+	unsigned long end_of_ram = 0x8000000;
+	unsigned long avail_ram = end_of_ram - (unsigned long)_end;
+
+	simple_alloc_init(_end, avail_ram, 32, 64);
+	ebony_init((u8 *)OPENBIOS_MAC_BASE,
+		   (u8 *)(OPENBIOS_MAC_BASE + OPENBIOS_MAC_OFFSET));
+}