Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted

Pull futex fix from Ingo Molnar:

 - Also allocate a default private futex hash on vfork() as well, to
   avoid races with (private) futex waiters (Peter Zijlstra)

* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Also allocate private hash on vfork()

1 files changed, 27 insertions, 0 deletions

diff --git a/Documentation/driver-api/firmware/introduction.rst b/Documentation/driver-api/firmware/introduction.rst
new file mode 100644
index 000000000..211cb44eb
--- /dev/null
+++ b/Documentation/driver-api/firmware/introduction.rst
@@ -0,0 +1,27 @@
+============
+Introduction
+============
+
+The firmware API enables kernel code to request files required
+for functionality from userspace, the uses vary:
+
+* Microcode for CPU errata
+* Device driver firmware, required to be loaded onto device
+  microcontrollers
+* Device driver information data (calibration data, EEPROM overrides),
+  some of which can be completely optional.
+
+Types of firmware requests
+==========================
+
+There are two types of calls:
+
+* Synchronous
+* Asynchronous
+
+Which one you use vary depending on your requirements, the rule of thumb
+however is you should strive to use the asynchronous APIs unless you also
+are already using asynchronous initialization mechanisms which will not
+stall or delay boot. Even if loading firmware does not take a lot of time
+processing firmware might, and this can still delay boot or initialization,
+as such mechanisms such as asynchronous probe can help supplement drivers.