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

[Daniel Axtens <dja@axtens.net>]

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?

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