RDMA/efa: CQ notifications

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>

RDMA/efa: Remove duplication of upper/lower_32_bits

The EFA_DMA_ADDR_TO_UINT32_HIGH/LOW macros are the same as the kernel's
upper/lower_32_bits, remove them and use kernel macros instead.

Link: https://lore.kernel.org/r/20210126120702.9807-3-galpress@amazon.com
Reviewed-by: Firas JahJah <firasj@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/efa: Remove redundant NULL pointer check of CQE

A pointer to store the command completion must be provided as it is always
used in efa_com_put_comp_ctx() to return the completion context back to
the pool. Remove the NULL pointer check and the redundant 'status' field
stored on the context as it could be retrieved from the completion itself.

Link: https://lore.kernel.org/r/20210126120702.9807-2-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>

RDMA/hw/efa/efa_com: Stop using param description notation for non-params

Fixes the following W=1 kernel build warning(s):

drivers/infiniband/hw/efa/efa_com.c:801: warning: Excess function parameter 'note' description in 'efa_com_admin_q_comp_intr_handler'

Link: https://lore.kernel.org/r/20210121094519.2044049-4-lee.jones@linaro.org
Cc: Gal Pressman <galpress@amazon.com>
Cc: Yossi Leybovich <sleybo@amazon.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/efa: Count admin commands errors

Add a new stat that counts admin commands failures, which might help when
debugging different issues.

Link: https://lore.kernel.org/r/20200420062213.44577-4-galpress@amazon.com
Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/efa: Properly document the interrupt mask register

The fact that the LSB in the register is the enable bit should not be an
implicit assumption between the driver and the device, properly document
that in the register definition.

Link: https://lore.kernel.org/r/20200225114010.21790-3-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@mellanox.com>

RDMA/efa: Unified getters/setters for device structs bitmask access

Use unified macros for device structs access instead of open coding the
shifts and masks over and over again.

Link: https://lore.kernel.org/r/20200225114010.21790-2-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@mellanox.com>

RDMA/efa: Clear the admin command buffer prior to its submission

We cannot rely on the entry memcpy as we only copy the actual size of the
command, the rest of the bytes must be memset to zero.

Currently providing non-zero memory will not have any user visible impact.
However, since admin commands are extendable (in a backwards compatible
way) everything beyond the size of the command must be cleared to prevent
issues in the future.

Fixes: 0420e542569b ("RDMA/efa: Implement functions that submit and complete admin commands")
Link: https://lore.kernel.org/r/20191112092608.46964-1-galpress@amazon.com
Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
Reviewed-by: Firas JahJah <firasj@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/efa: Rate limit admin queue error prints

Admin queue error prints should never happen unless something wrong
happened to the device. However, in the unfortunate case that it does,
we should take extra care not to flood the log with error messages.

Reviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Link: https://lore.kernel.org/r/20190801171447.54440-3-galpress@amazon.com
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/efa: Entropy in admin commands id

Make admin commands id easier to distinguish by using relevant bits from
the producer counter.
This allows us to differentiate admin commands with the same producer
index (happens after admin queue overlap), which is helpful when
debugging.

Signed-off-by: Daniel Kranzdorf <dkkranzd@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@mellanox.com>

RDMA/efa: Remove unneeded admin commands abort flow

The admin commands abort flow is buggy (use-after-free) and not really
necessary as it is guaranteed that after ib_unregister_device() is called
there are no user verbs threads running in parallel, delete it.

Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
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@mellanox.com>

RDMA/efa: Implement functions that submit and complete admin commands

Add admin commands submissions/completions implementation.

Signed-off-by: Gal Pressman <galpress@amazon.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>