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, 48 insertions, 0 deletions

diff --git a/Documentation/driver-api/miscellaneous.rst b/Documentation/driver-api/miscellaneous.rst
new file mode 100644
index 000000000..4a5104a36
--- /dev/null
+++ b/Documentation/driver-api/miscellaneous.rst
@@ -0,0 +1,48 @@
+Parallel Port Devices
+=====================
+
+.. kernel-doc:: include/linux/parport.h
+   :internal:
+
+.. kernel-doc:: drivers/parport/ieee1284.c
+   :export:
+
+.. kernel-doc:: drivers/parport/share.c
+   :export:
+
+.. kernel-doc:: drivers/parport/daisy.c
+   :internal:
+
+16x50 UART Driver
+=================
+
+.. kernel-doc:: drivers/tty/serial/8250/8250_core.c
+   :export:
+
+See serial/driver.rst for related APIs.
+
+Pulse-Width Modulation (PWM)
+============================
+
+Pulse-width modulation is a modulation technique primarily used to
+control power supplied to electrical devices.
+
+The PWM framework provides an abstraction for providers and consumers of
+PWM signals. A controller that provides one or more PWM signals is
+registered as :c:type:`struct pwm_chip <pwm_chip>`. Providers
+are expected to embed this structure in a driver-specific structure.
+This structure contains fields that describe a particular chip.
+
+A chip exposes one or more PWM signal sources, each of which exposed as
+a :c:type:`struct pwm_device <pwm_device>`. Operations can be
+performed on PWM devices to control the period, duty cycle, polarity and
+active state of the signal.
+
+Note that PWM devices are exclusive resources: they can always only be
+used by one consumer at a time.
+
+.. kernel-doc:: include/linux/pwm.h
+   :internal:
+
+.. kernel-doc:: drivers/pwm/core.c
+   :export: