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, 64 insertions, 0 deletions

diff --git a/tools/crypto/ccp/dbc.py b/tools/crypto/ccp/dbc.py
new file mode 100644
index 000000000..2b91415b1
--- /dev/null
+++ b/tools/crypto/ccp/dbc.py
@@ -0,0 +1,64 @@
+#!/usr/bin/python3
+# SPDX-License-Identifier: GPL-2.0
+
+import ctypes
+import os
+
+DBC_UID_SIZE = 16
+DBC_NONCE_SIZE = 16
+DBC_SIG_SIZE = 32
+
+PARAM_GET_FMAX_CAP = (0x3,)
+PARAM_SET_FMAX_CAP = (0x4,)
+PARAM_GET_PWR_CAP = (0x5,)
+PARAM_SET_PWR_CAP = (0x6,)
+PARAM_GET_GFX_MODE = (0x7,)
+PARAM_SET_GFX_MODE = (0x8,)
+PARAM_GET_CURR_TEMP = (0x9,)
+PARAM_GET_FMAX_MAX = (0xA,)
+PARAM_GET_FMAX_MIN = (0xB,)
+PARAM_GET_SOC_PWR_MAX = (0xC,)
+PARAM_GET_SOC_PWR_MIN = (0xD,)
+PARAM_GET_SOC_PWR_CUR = (0xE,)
+
+DEVICE_NODE = "/dev/dbc"
+
+lib = ctypes.CDLL("./dbc_library.so", mode=ctypes.RTLD_GLOBAL)
+
+
+def handle_error(code):
+    raise OSError(code, os.strerror(code))
+
+
+def get_nonce(device, signature):
+    if not device:
+        raise ValueError("Device required")
+    buf = ctypes.create_string_buffer(DBC_NONCE_SIZE)
+    ret = lib.get_nonce(device.fileno(), ctypes.byref(buf), signature)
+    if ret:
+        handle_error(ret)
+    return buf.value
+
+
+def set_uid(device, new_uid, signature):
+    if not signature:
+        raise ValueError("Signature required")
+    if not new_uid:
+        raise ValueError("UID required")
+    ret = lib.set_uid(device.fileno(), new_uid, signature)
+    if ret:
+        handle_error(ret)
+    return True
+
+
+def process_param(device, message, signature, data=None):
+    if not signature:
+        raise ValueError("Signature required")
+    if type(message) != tuple:
+        raise ValueError("Expected message tuple")
+    arg = ctypes.c_int(data if data else 0)
+    sig = ctypes.create_string_buffer(signature, len(signature))
+    ret = lib.process_param(device.fileno(), message[0], ctypes.pointer(sig), ctypes.pointer(arg))
+    if ret:
+        handle_error(ret)
+    return arg.value, sig.value