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, 19 insertions, 0 deletions

diff --git a/drivers/bcma/README b/drivers/bcma/README
new file mode 100644
index 000000000..f7e7ce46c
--- /dev/null
+++ b/drivers/bcma/README
@@ -0,0 +1,19 @@
+Broadcom introduced new bus as replacement for older SSB. It is based on AMBA,
+however from programming point of view there is nothing AMBA specific we use.
+
+Standard AMBA drivers are platform specific, have hardcoded addresses and use
+AMBA standard fields like CID and PID.
+
+In case of Broadcom's cards every device consists of:
+1) Broadcom specific AMBA device. It is put on AMBA bus, but can not be treated
+   as standard AMBA device. Reading it's CID or PID can cause machine lockup.
+2) AMBA standard devices called ports or wrappers. They have CIDs (AMBA_CID)
+   and PIDs (0x103BB369), but we do not use that info for anything. One of that
+   devices is used for managing Broadcom specific core.
+
+Addresses of AMBA devices are not hardcoded in driver and have to be read from
+EPROM.
+
+In this situation we decided to introduce separated bus. It can contain up to
+16 devices identified by Broadcom specific fields: manufacturer, id, revision
+and class.