RDMA/iw_cxgb4: Fix refcount underflow while destroying cqs.

Previous atomic increment/decrement logic expects the atomic count to be
'0' after the final decrement.

Replacing atomic count with refcount does not allow that, as
refcount_dec() considers count of 1 as underflow and triggers a kernel
splat.

Fix the current refcount logic by using the usual pattern of decrementing
the refcount and test if it is '0' on the final deref in
c4iw_destroy_cq(). Use wait_for_completion() instead of wait_event().

Fixes: 7183451f846d ("RDMA/cxgb4: Use refcount_t instead of atomic_t for reference counting")
Link: https://lore.kernel.org/r/1628167412-12114-1-git-send-email-dakshaja@chelsio.com
Signed-off-by: Dakshaja Uppalapati <dakshaja@chelsio.com>
Reviewed-by: Potnuri Bharat Teja <bharat@chelsio.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/cxgb4: Use refcount_t instead of atomic_t for reference counting

The refcount_t API will WARN on underflow and overflow of a reference
counter, and avoid use-after-free risks.

Link: https://lore.kernel.org/r/1622194663-2383-12-git-send-email-liweihang@huawei.com
Cc: Potnuri Bharat Teja <bharat@chelsio.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

cxgb4: Convert qpidr to XArray

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

cxgb4: Convert cqidr to XArray

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

rdma/cxgb4: Add support for 64Byte cqes

This patch adds support for iw_cxb4 to extend cqes from existing 32Byte
size to 64Byte.

Also includes adds backward compatibility support (for 32Byte) to work
with older libraries.

Signed-off-by: Raju Rangoju <rajur@chelsio.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

iw_cxgb4: Change error/warn prints to pr_debug

These prints not neccesarily mean error/warning, so changing them to
debug.

Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

iw_cxgb4: only call the cq comp_handler when the cq is armed

The ULPs completion handler should only be called if the CQ is
armed for notification.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

iw_cxgb4: change pr_debug to appropriate log level

Error logs of iw_cxgb4 needs to be printed by default. This patch
changes the necessary pr_debug() to appropriate pr_<log level>.

Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

cxgb4: Convert PDBG to pr_debug

Use a more typical logging style.

Miscellanea:

o Obsolete the c4iw_debug module parameter
o Coalesce formats
o Realign arguments

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

cxgb4: Use more common logging style

Convert printks to pr_<level>

Miscellanea:

o Coalesce formats
o Realign arguments

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDMA/cxgb4: Serialize CQ event upcalls with CQ destruction

A race exists where the application can be destroying the CQ concurrently
with a HW interrupt indicating a completion has been inserted into the CQ.
This can cause an event notification upcall to the application after the
CQ has been destroyed.

The solution is to serialize looking up the CQ in the IDR table and
referencing the CQ in c4iw_ev_handler() with removing the CQID from the
IDR table and blocking until the refcnt reaches 0 in c4iw_destroy_cq().

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

iw_cxgb4: Cleanup register defines/MACROS defined in t4fw_ri_api.h

Cleanup all the MACROS that are defined in t4fw_ri_api.h and affected files

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

iw_cxgb4: Cleanup register defines/MACROS defined in t4fw_ri_api.h

Cleanup all the MACROS that are defined in t4fw_ri_api.h and affected files

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDMA/cxgb4: Only call CQ completion handler if it is armed

The function __flush_qp() always calls the ULP's CQ completion handler
functions even if the CQ was not armed. This can crash the system if
the function pointer is NULL. The iSER ULP behaves this way: no
completion handler and never arm the CQ for notification. So now we
track whether the CQ is armed at flush time and only call the
completion handlers if their CQs were armed.

Also, if the RCQ and SCQ are the same CQ, the completion handler is
getting called twice. It should only be called once after all SQ and
RQ WRs are flushed from the QP. So rearrange the logic to fix this.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

cxgb4/iw_cxgb4: display TPTE on errors

With ingress WRITE or READ RESPONSE errors, HW provides the offending
stag from the packet. This patch adds logic to log the parsed TPTE
in this case. cxgb4 now exports a function to read a TPTE entry
from adapter memory.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDMA/cxgb4: Handle newer firmware changes

Move QP to TERMINATE instead to allow the peer to get the TERM
message. This bug wasn't detectable until newer FW that moves
connections out of RDMA mode as soon as an error is detected.

QP can exit RTS before the last AE arrives. This was introduced by
changes in the FW to kick connections out of RDMA mode as soon as an
error is detected. A side effect of this is that the driver can move
the QP out of RTS before the AE causing the connection to get kicked
out of RDMA mode is processed. Fix for this is to always post async
errors even if the QP is out of RTS.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/cxgb4: Always log async errors

Log AEs even if the QP isn't in RTS. It is useful information.

Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/cxgb4: Disable interrupts in c4iw_ev_dispatch()

Use GFP_ATOMIC in _insert_handle() if ints are disabled.

Don't panic if we get an abort with no endpoint found. Just log a
warning.

Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/cxgb4: Serialize calls to CQ's comp_handler

Commit 01e7da6ba53c ("RDMA/cxgb4: Make sure flush CQ entries are
collected on connection close") introduced a potential problem where a
CQ's comp_handler can get called simultaneously from different places
in the iw_cxgb4 driver. This does not comply with
Documentation/infiniband/core_locking.txt, which states that at a
given point of time, there should be only one callback per CQ should
be active.

This problem was reported by Parav Pandit <Parav.Pandit@Emulex.Com>.
Based on discussion between Parav Pandit and Steve Wise, this patch
fixes the above problem by serializing the calls to a CQ's
comp_handler using a spin_lock.

Reported-by: Parav Pandit <Parav.Pandit@Emulex.Com>
Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

RDMA/cxgb4: Handle CPL_RDMA_TERMINATE messages

T4 FW sends up CPL_RDMA_TERMINATE to indicate a peer TERM. This
triggers the QP moving to TERMINATE state.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

MAINTAINERS: Add cxgb4 and iw_cxgb4 entries

Signed-off-by: Roland Dreier <rolandd@cisco.com>

RDMA/cxgb4: Add driver for Chelsio T4 RNIC

Add an RDMA/iWARP driver for Chelsio T4 Ethernet adapters.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>