The Virtual Accelerator Switchboard (VAS) subsystem in the POWER9 processor
provides a low latency Core-to-core wakeup" mechanism which allows a thread
on one core the processor to efficiently send a message to a thread waiting
on another core.
This Fast thread-wakeup (FTW) driver provides user space applications an
interface to the Core-to-core wakeup mechanism. The FTW driver uses the
"external" interfaces provided by the VAS driver to interact with the VAS
hardware.
PATCH 5/5 documents the API.
The ftw-next branch on my github has some initial test cases for the
driver:
https://github.com/sukadev/linux/tree/ftw-next
Thanks to input from Ben Herrenschmidt, Michael Ellerman, Michael
Neuling and Robert Blackmore.
Sukadev Bhattiprolu (5):
powerpc/vas: Remove a stray line in Makefile
powerpc/ftw: Define FTW_SETUP ioctl API
powerpc/ftw: Implement a simple FTW driver
powerpc/ftw: Add a couple of trace points
powerpc/ftw: Document FTW API/usage
Documentation/powerpc/ftw-api.txt | 283 +++++++++++++++++++++++++
MAINTAINERS | 8 +
arch/powerpc/platforms/powernv/Makefile | 1 -
drivers/misc/Kconfig | 1 +
drivers/misc/Makefile | 1 +
drivers/misc/ftw/Kconfig | 16 ++
drivers/misc/ftw/Makefile | 4 +
drivers/misc/ftw/ftw-trace.h | 75 +++++++
drivers/misc/ftw/ftw.c | 352 ++++++++++++++++++++++++++++++++
include/uapi/misc/ftw.h | 31 +++
10 files changed, 771 insertions(+), 1 deletion(-)
create mode 100644 Documentation/powerpc/ftw-api.txt
create mode 100644 drivers/misc/ftw/Kconfig
create mode 100644 drivers/misc/ftw/Makefile
create mode 100644 drivers/misc/ftw/ftw-trace.h
create mode 100644 drivers/misc/ftw/ftw.c
create mode 100644 include/uapi/misc/ftw.h
--
2.7.4
