This patch adds support for CQ notifications through the standard verbs
api.
In order to achieve that, a new event queue (EQ) object is introduced,
which is in charge of reporting completion events to the driver. On
driver load, EQs are allocated and their affinity is set to a single
cpu. When a user app creates a CQ with a completion channel, the
completion vector number is converted to a EQ number, which is in charge
of reporting the CQ events.
In addition, the CQ creation admin command now returns an offset for the
CQ doorbell, which is mapped to the userspace provider and is used to arm
the CQ when requested by the user.
The EQs use a single doorbell (located on the registers BAR), which
encodes the EQ number and arm as part of the doorbell value. The EQs are
polled by the driver on each new EQE, and arm it when the poll is
completed.
Link: https://lore.kernel.org/r/20211003105605.29222-1-galpress@amazon.com
Reviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Introduce a mechanism that performs an handshake between the userspace
provider and kernel driver which verifies that the user supports all
required features in order to operate correctly.
The handshake verifies the needed functionality by comparing the reported
device caps and the provider caps. If the device reports a non-zero
capability the appropriate comp mask is required from the userspace
provider in order to allocate the context.
Link: https://lore.kernel.org/r/20200722140312.3651-4-galpress@amazon.com
Reviewed-by: Shadi Ammouri <sammouri@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
