Re: [PATCH v3 0/9] crypto/nx: Enable GZIP engine and provide userpace API

[Haren Myneni <haren@linux.ibm.com>]

On Tue, 2020-03-17 at 00:04 +1100, Daniel Axtens wrote:
> Hi Haren,
> 
> If I understand correctly, to test these, I need to apply both this
> series and your VAS userspace page fault handling series - is that
> right?

Daniel, 

Yes, This patch series enables GZIP engine and provides user space API.
Whereas VAS fault handling series process faults if NX sees fault on
request buffer.  

selftest -
https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-March/206035.html

or https://github.com/abalib/power-gzip/tree/develop/selftest

More tests are available - https://github.com/abalib/power-gzip

libnxz - https://github.com/libnxz/power-gzip  

Thanks
Haren

> 
> Kind regards,
> Daniel
> 
> > Power9 processor supports Virtual Accelerator Switchboard (VAS) which
> > allows kernel and userspace to send compression requests to Nest
> > Accelerator (NX) directly. The NX unit comprises of 2 842 compression
> > engines and 1 GZIP engine. Linux kernel already has 842 compression
> > support on kernel. This patch series adds GZIP compression support
> > from user space. The GZIP Compression engine implements the ZLIB and
> > GZIP compression algorithms. No plans of adding NX-GZIP compression
> > support in kernel right now.
> >
> > Applications can send requests to NX directly with COPY/PASTE
> > instructions. But kernel has to establish channel / window on NX-GZIP
> > device for the userspace. So userspace access to the GZIP engine is
> > provided through /dev/crypto/nx-gzip device with several operations.
> >
> > An application must open the this device to obtain a file descriptor (fd).
> > Using the fd, application should issue the VAS_TX_WIN_OPEN ioctl to
> > establish a connection to the engine. Once window is opened, should use
> > mmap() system call to map the hardware address of engine's request queue
> > into the application's virtual address space. Then user space forms the
> > request as co-processor Request Block (CRB) and paste this CRB on the
> > mapped HW address using COPY/PASTE instructions. Application can poll
> > on status flags (part of CRB) with timeout for request completion.
> >
> > For VAS_TX_WIN_OPEN ioctl, if user space passes vas_id = -1 (struct
> > vas_tx_win_open_attr), kernel determines the VAS instance on the
> > corresponding chip based on the CPU on which the process is executing.
> > Otherwise, the specified VAS instance is used if application passes the
> > proper VAS instance (vas_id listed in /proc/device-tree/vas@*/ibm,vas_id).
> >
> > Process can open multiple windows with different FDs or can send several
> > requests to NX on the same window at the same time.
> >
> > A userspace library libnxz is available:
> >         https://github.com/abalib/power-gzip
> >
> > Applications that use inflate/deflate calls can link with libNXz and use
> > NX GZIP compression without any modification.
> >
> > Tested the available 842 compression on power8 and power9 system to make
> > sure no regression and tested GZIP compression on power9 with tests
> > available in the above link.
> >
> > Thanks to Bulent Abali for nxz library and tests development.
> >
> > Changelog:
> > V2:
> >   - Move user space API code to powerpc as suggested. Also this API
> >     can be extended to any other coprocessor type that VAS can support
> >     in future. Example: Fast thread wakeup feature from VAS
> >   - Rebased to 5.6-rc3
> >
> > V3:
> >   - Fix sparse warnings (patches 3&6)
> >
> > Haren Myneni (9):
> >   powerpc/vas: Initialize window attributes for GZIP coprocessor type
> >   powerpc/vas: Define VAS_TX_WIN_OPEN ioctl API
> >   powerpc/vas: Add VAS user space API
> >   crypto/nx: Initialize coproc entry with kzalloc
> >   crypto/nx: Rename nx-842-powernv file name to nx-common-powernv
> >   crypto/NX: Make enable code generic to add new GZIP compression type
> >   crypto/nx: Enable and setup GZIP compresstion type
> >   crypto/nx: Remove 'pid' in vas_tx_win_attr struct
> >   Documentation/powerpc: VAS API
> >
> >  Documentation/powerpc/index.rst                    |    1 +
> >  Documentation/powerpc/vas-api.rst                  |  246 +++++
> >  Documentation/userspace-api/ioctl/ioctl-number.rst |    1 +
> >  arch/powerpc/include/asm/vas.h                     |   12 +-
> >  arch/powerpc/include/uapi/asm/vas-api.h            |   22 +
> >  arch/powerpc/platforms/powernv/Makefile            |    2 +-
> >  arch/powerpc/platforms/powernv/vas-api.c           |  290 +++++
> >  arch/powerpc/platforms/powernv/vas-window.c        |   23 +-
> >  arch/powerpc/platforms/powernv/vas.h               |    2 +
> >  drivers/crypto/nx/Makefile                         |    2 +-
> >  drivers/crypto/nx/nx-842-powernv.c                 | 1062 ------------------
> >  drivers/crypto/nx/nx-common-powernv.c              | 1133 ++++++++++++++++++++
> >  12 files changed, 1723 insertions(+), 1073 deletions(-)
> >  create mode 100644 Documentation/powerpc/vas-api.rst
> >  create mode 100644 arch/powerpc/include/uapi/asm/vas-api.h
> >  create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
> >  delete mode 100644 drivers/crypto/nx/nx-842-powernv.c
> >  create mode 100644 drivers/crypto/nx/nx-common-powernv.c
> >
> > -- 
> > 1.8.3.1