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.

3 files changed, 157 insertions, 0 deletions

diff --git a/Documentation/admin-guide/auxdisplay/cfag12864b.rst b/Documentation/admin-guide/auxdisplay/cfag12864b.rst
new file mode 100644
index 000000000..da385d851
--- /dev/null
+++ b/Documentation/admin-guide/auxdisplay/cfag12864b.rst
@@ -0,0 +1,98 @@
+===================================
+cfag12864b LCD Driver Documentation
+===================================
+
+:License:		GPLv2
+:Author & Maintainer:	Miguel Ojeda <ojeda@kernel.org>
+:Date:			2006-10-27
+
+
+
+.. INDEX
+
+	1. DRIVER INFORMATION
+	2. DEVICE INFORMATION
+	3. WIRING
+	4. USERSPACE PROGRAMMING
+
+1. Driver Information
+---------------------
+
+This driver supports a cfag12864b LCD.
+
+
+2. Device Information
+---------------------
+
+:Manufacturer:	Crystalfontz
+:Device Name:	Crystalfontz 12864b LCD Series
+:Device Code:	cfag12864b
+:Webpage:	http://www.crystalfontz.com
+:Device Webpage: http://www.crystalfontz.com/products/12864b/
+:Type:		LCD (Liquid Crystal Display)
+:Width:		128
+:Height:	64
+:Colors:	2 (B/N)
+:Controller:	ks0108
+:Controllers:	2
+:Pages:		8 each controller
+:Addresses:	64 each page
+:Data size:	1 byte each address
+:Memory size:	2 * 8 * 64 * 1 = 1024 bytes = 1 Kbyte
+
+
+3. Wiring
+---------
+
+The cfag12864b LCD Series don't have official wiring.
+
+The common wiring is done to the parallel port as shown::
+
+  Parallel Port                          cfag12864b
+
+    Name Pin#                            Pin# Name
+
+  Strobe ( 1)------------------------------(17) Enable
+  Data 0 ( 2)------------------------------( 4) Data 0
+  Data 1 ( 3)------------------------------( 5) Data 1
+  Data 2 ( 4)------------------------------( 6) Data 2
+  Data 3 ( 5)------------------------------( 7) Data 3
+  Data 4 ( 6)------------------------------( 8) Data 4
+  Data 5 ( 7)------------------------------( 9) Data 5
+  Data 6 ( 8)------------------------------(10) Data 6
+  Data 7 ( 9)------------------------------(11) Data 7
+         (10)                      [+5v]---( 1) Vdd
+         (11)                      [GND]---( 2) Ground
+         (12)                      [+5v]---(14) Reset
+         (13)                      [GND]---(15) Read / Write
+    Line (14)------------------------------(13) Controller Select 1
+         (15)
+    Init (16)------------------------------(12) Controller Select 2
+  Select (17)------------------------------(16) Data / Instruction
+  Ground (18)---[GND]              [+5v]---(19) LED +
+  Ground (19)---[GND]
+  Ground (20)---[GND]              E    A             Values:
+  Ground (21)---[GND]       [GND]---[P1]---(18) Vee    - R = Resistor = 22 ohm
+  Ground (22)---[GND]                |                 - P1 = Preset = 10 Kohm
+  Ground (23)---[GND]       ----   S ------( 3) V0     - P2 = Preset = 1 Kohm
+  Ground (24)---[GND]       |  |
+  Ground (25)---[GND] [GND]---[P2]---[R]---(20) LED -
+
+
+4. Userspace Programming
+------------------------
+
+The cfag12864bfb describes a framebuffer device (/dev/fbX).
+
+It has a size of 1024 bytes = 1 Kbyte.
+Each bit represents one pixel. If the bit is high, the pixel will
+turn on. If the pixel is low, the pixel will turn off.
+
+You can use the framebuffer as a file: fopen, fwrite, fclose...
+Although the LCD won't get updated until the next refresh time arrives.
+
+Also, you can mmap the framebuffer: open & mmap, munmap & close...
+which is the best option for most uses.
+
+Check samples/auxdisplay/cfag12864b-example.c
+for a real working userspace complete program with usage examples.
diff --git a/Documentation/admin-guide/auxdisplay/index.rst b/Documentation/admin-guide/auxdisplay/index.rst
new file mode 100644
index 000000000..31eae0825
--- /dev/null
+++ b/Documentation/admin-guide/auxdisplay/index.rst
@@ -0,0 +1,9 @@
+=========================
+Auxiliary Display Support
+=========================
+
+.. toctree::
+    :maxdepth: 1
+
+    ks0108.rst
+    cfag12864b.rst
diff --git a/Documentation/admin-guide/auxdisplay/ks0108.rst b/Documentation/admin-guide/auxdisplay/ks0108.rst
new file mode 100644
index 000000000..a7d3fe509
--- /dev/null
+++ b/Documentation/admin-guide/auxdisplay/ks0108.rst
@@ -0,0 +1,50 @@
+==========================================
+ks0108 LCD Controller Driver Documentation
+==========================================
+
+:License:		GPLv2
+:Author & Maintainer:	Miguel Ojeda <ojeda@kernel.org>
+:Date:			2006-10-27
+
+
+
+.. INDEX
+
+	1. DRIVER INFORMATION
+	2. DEVICE INFORMATION
+	3. WIRING
+
+
+1. Driver Information
+---------------------
+
+This driver supports the ks0108 LCD controller.
+
+
+2. Device Information
+---------------------
+
+:Manufacturer:	Samsung
+:Device Name:	KS0108 LCD Controller
+:Device Code:	ks0108
+:Webpage:	-
+:Device Webpage: -
+:Type:		LCD Controller (Liquid Crystal Display Controller)
+:Width:		64
+:Height:	64
+:Colors:	2 (B/N)
+:Pages:		8
+:Addresses:	64 each page
+:Data size:	1 byte each address
+:Memory size:	8 * 64 * 1 = 512 bytes
+
+
+3. Wiring
+---------
+
+The driver supports data parallel port wiring.
+
+If you aren't building LCD related hardware, you should check
+your LCD specific wiring information in the same folder.
+
+For example, check Documentation/admin-guide/auxdisplay/cfag12864b.rst