v4.19.13 snapshot.
diff --git a/Documentation/ABI/testing/sysfs-block-device b/Documentation/ABI/testing/sysfs-block-device
new file mode 100644
index 0000000..82ef6ea
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-block-device
@@ -0,0 +1,58 @@
+What: /sys/block/*/device/sw_activity
+Date: Jun, 2008
+KernelVersion: v2.6.27
+Contact: linux-ide@vger.kernel.org
+Description:
+ (RW) Used by drivers which support software controlled activity
+ LEDs.
+
+ It has the following valid values:
+
+ 0 OFF - the LED is not activated on activity
+ 1 BLINK_ON - the LED blinks on every 10ms when activity is
+ detected.
+ 2 BLINK_OFF - the LED is on when idle, and blinks off
+ every 10ms when activity is detected.
+
+ Note that the user must turn sw_activity OFF it they wish to
+ control the activity LED via the em_message file.
+
+
+What: /sys/block/*/device/unload_heads
+Date: Sep, 2008
+KernelVersion: v2.6.28
+Contact: linux-ide@vger.kernel.org
+Description:
+ (RW) Hard disk shock protection
+
+ Writing an integer value to this file will take the heads of the
+ respective drive off the platter and block all I/O operations
+ for the specified number of milliseconds.
+
+ - If the device does not support the unload heads feature,
+ access is denied with -EOPNOTSUPP.
+ - The maximal value accepted for a timeout is 30000
+ milliseconds.
+ - A previously set timeout can be cancelled and disk can resume
+ normal operation immediately by specifying a timeout of 0.
+ - Some hard drives only comply with an earlier version of the
+ ATA standard, but support the unload feature nonetheless.
+ There is no safe way Linux can detect these devices, so this
+ is not enabled by default. If it is known that your device
+ does support the unload feature, then you can tell the kernel
+ to enable it by writing -1. It can be disabled again by
+ writing -2.
+ - Values below -2 are rejected with -EINVAL
+
+ For more information, see
+ Documentation/laptops/disk-shock-protection.txt
+
+
+What: /sys/block/*/device/ncq_prio_enable
+Date: Oct, 2016
+KernelVersion: v4.10
+Contact: linux-ide@vger.kernel.org
+Description:
+ (RW) Write to the file to turn on or off the SATA ncq (native
+ command queueing) support. By default this feature is turned
+ off.