On Sun, Dec 15, 2019 at 05:05:19AM -0800, Haren Myneni wrote:

On power9, userspace can send GZIP compression requests directly to NX
once kernel establishes NX channel / window. This patch provides GZIP
engine access to user space via /dev/crypto/nx-gzip device node with
open, VAS_TX_WIN_OPEN ioctl, mmap and close operations.

Each window corresponds to file descriptor and application can open
multiple windows. After the window is opened, mmap() system call to map
the hardware address of engine's request queue into the application's
virtual address space.

Then the application can then submit one or more requests to the the
engine by using the copy/paste instructions and pasting the CRBs to
the virtual address (aka paste_address) returned by mmap().

Signed-off-by: Sukadev Bhattiprolu <redacted>
Signed-off-by: Haren Myneni <haren@us.ibm.com>
---
 drivers/crypto/nx/Makefile            |   2 +-
 drivers/crypto/nx/nx-842-powernv.h    |   2 +
 drivers/crypto/nx/nx-commom-powernv.c |  21 ++-
 drivers/crypto/nx/nx-gzip-powernv.c   | 282 ++++++++++++++++++++++++++++++++++
 4 files changed, 304 insertions(+), 3 deletions(-)
 create mode 100644 drivers/crypto/nx/nx-gzip-powernv.c

We already have a kernel compress API which could be exposed
to user-space through af_alg.  If every driver created their
own user-space API it would be unmanageable.

Cheers,
-- 
Email: Herbert Xu [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt