Commit Graph

13 Commits

Author SHA1 Message Date
Devesh Sharma
6e04b10356 RDMA/bnxt_re: Fix broken RoCE driver due to recent L2 driver changes
The recent changes in Broadcom's ethernet driver(L2 driver) broke
RoCE functionality in terms of MSIx vector allocation and
de-allocation.

There is a possibility that L2 driver would initiate MSIx vector
reallocation depending upon the requests coming from administrator.
In such cases L2 driver needs to free up all the MSIx vectors
allocated previously and reallocate/initialize those.

If RoCE driver is loaded and reshuffling is attempted, there will be
kernel crashes because RoCE driver would still be holding the MSIx
vectors but L2 driver would attempt to free in-use vectors. Thus
leading to a kernel crash.

Making changes in roce driver to fix crashes described above.
As part of solution L2 driver tells RoCE driver to release
the MSIx vector whenever there is a need. When RoCE driver
get message it sync up with all the running tasklets and IRQ
handlers and releases the vectors. L2 driver send one more
message to RoCE driver to resume the MSIx vectors. L2 driver
guarantees that RoCE vector do not change during reshuffling.

Fixes: ec86f14ea5 ("bnxt_en: Add ULP calls to stop and restart IRQs.")
Fixes: 08654eb213 ("bnxt_en: Change IRQ assignment for RDMA driver.")
Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-05-25 11:03:47 -06:00
Selvin Xavier
942c9b6ca8 RDMA/bnxt_re: Avoid Hard lockup during error CQE processing
Hitting the following hardlockup due to a race condition in
error CQE processing.

[26146.879798] bnxt_en 0000:04:00.0: QPLIB: FP: CQ Processed Req
[26146.886346] bnxt_en 0000:04:00.0: QPLIB: wr_id[1251] = 0x0 with status 0xa
[26156.350935] NMI watchdog: Watchdog detected hard LOCKUP on cpu 4
[26156.357470] Modules linked in: nfsd auth_rpcgss nfs_acl lockd grace
[26156.447957] CPU: 4 PID: 3413 Comm: kworker/4:1H Kdump: loaded
[26156.457994] Hardware name: Dell Inc. PowerEdge R430/0CN7X8,
[26156.466390] Workqueue: ib-comp-wq ib_cq_poll_work [ib_core]
[26156.472639] Call Trace:
[26156.475379]  <NMI>  [<ffffffff98d0d722>] dump_stack+0x19/0x1b
[26156.481833]  [<ffffffff9873f775>] watchdog_overflow_callback+0x135/0x140
[26156.489341]  [<ffffffff9877f237>] __perf_event_overflow+0x57/0x100
[26156.496256]  [<ffffffff98787c24>] perf_event_overflow+0x14/0x20
[26156.502887]  [<ffffffff9860a580>] intel_pmu_handle_irq+0x220/0x510
[26156.509813]  [<ffffffff98d16031>] perf_event_nmi_handler+0x31/0x50
[26156.516738]  [<ffffffff98d1790c>] nmi_handle.isra.0+0x8c/0x150
[26156.523273]  [<ffffffff98d17be8>] do_nmi+0x218/0x460
[26156.528834]  [<ffffffff98d16d79>] end_repeat_nmi+0x1e/0x7e
[26156.534980]  [<ffffffff987089c0>] ? native_queued_spin_lock_slowpath+0x1d0/0x200
[26156.543268]  [<ffffffff987089c0>] ? native_queued_spin_lock_slowpath+0x1d0/0x200
[26156.551556]  [<ffffffff987089c0>] ? native_queued_spin_lock_slowpath+0x1d0/0x200
[26156.559842]  <EOE>  [<ffffffff98d083e4>] queued_spin_lock_slowpath+0xb/0xf
[26156.567555]  [<ffffffff98d15690>] _raw_spin_lock+0x20/0x30
[26156.573696]  [<ffffffffc08381a1>] bnxt_qplib_lock_buddy_cq+0x31/0x40 [bnxt_re]
[26156.581789]  [<ffffffffc083bbaa>] bnxt_qplib_poll_cq+0x43a/0xf10 [bnxt_re]
[26156.589493]  [<ffffffffc083239b>] bnxt_re_poll_cq+0x9b/0x760 [bnxt_re]

The issue happens if RQ poll_cq or SQ poll_cq or Async error event tries to
put the error QP in flush list. Since SQ and RQ of each error qp are added
to two different flush list, we need to protect it using locks of
corresponding CQs. Difference in order of acquiring the lock in
SQ poll_cq and RQ poll_cq can cause a hard lockup.

Revisits the locking strategy and removes the usage of qplib_cq.hwq.lock.
Instead of this lock, introduces qplib_cq.flush_lock to handle
addition/deletion of QPs in flush list. Also, always invoke the flush_lock
in order (SQ CQ lock first and then RQ CQ lock) to avoid any potential
deadlock.

Other than the poll_cq context, the movement of QP to/from flush list can
be done in modify_qp context or from an async error event from HW.
Synchronize these operations using the bnxt_re verbs layer CQ locks.
To achieve this, adds a call back to the HW abstraction layer(qplib) to
bnxt_re ib_verbs layer in case of async error event. Also, removes the
buddy cq functions as it is no longer required.

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-03-06 20:08:39 -07:00
Devesh Sharma
c354dff00d RDMA/bnxt_re: Fix incorrect DB offset calculation
To support host systems with non 4K page size, l2_db_size shall be
calculated with 4096 instead of PAGE_SIZE. Also, supply the host page size
to FW during initialization.

Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-02-28 12:10:32 -07:00
Devesh Sharma
37cb11acf1 RDMA/bnxt_re: Add SRQ support for Broadcom adapters
Shared receive queue (SRQ) is defined as a pool of
receive buffers shared among multiple QPs which belong
to same protection domain in a given process context.
Use of SRQ reduces the memory foot print of IB applications.

Broadcom adapters support SRQ, adding code-changes to enable
shared receive queue.

Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2018-01-18 14:49:19 -05:00
Selvin Xavier
2fc68543f2 RDMA/bnxt_re: Add support for query firmware version
The device now reports firmware version thus, removing
the hard coded values of the FW version string and
redundant fw_rev hook from sysfs. Adding code to query
firmware version from underlying device and report it
through the kernel verb to get firmware version string.

Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2018-01-17 09:56:17 -05:00
Somnath Kotur
9b40183c08 RDMA/bnxt_re: Add memory barriers when processing CQ/EQ entries
The code determines if the next ring entry is valid before proceeding
further to read the rest of the entry. The CPU can re-order and read
the rest of the entry first, possibly reading a stale entry, if DMA
of a new entry happens right after reading it.

Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-11-13 15:53:57 -05:00
Sriharsha Basavapatna
d6d5c59905 bnxt_re: fix a crash in qp error event processing
In bnxt_qplib_process_qp_event(), for qp error events we look up the
qp-handle and pass it for further processing. But we don't check if the
handle is NULL. This could lead to a crash in the called functions when
that qp-handle is dereferenced, if the qp is destroyed in the meantime.
Fix this by checking for a valid qp-handle in that function.

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-11-13 15:01:25 -05:00
Somnath Kotur
a0ddc2ec8f bnxt_re: Fix incorrect usage of test_bit()
test_bit() takes a bit number while the 'flags' field in
struct bnxt_qplib_rcfw was using actual BIT position converted
values.
Fix this by assigning bit numbers and use consistent APIs
all the flag values.
Also logging a message in case of failure.

Thanks to Dan Carpenter for pointing this out.

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-10-18 10:24:12 -04:00
Bart Van Assche
6dfa8ae6b4 RDMA/bnxt_re: Remove set-but-not-used variables
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-10-14 20:47:05 -04:00
Somnath Kotur
2b6376305d bnxt_re: Stop issuing further cmds to FW once a cmd times out
Once a cmd to FW times out(after 20s) it is reasonable to
assume the FW or atleast the control path is dead.
No point issuing further cmds to the FW as each subsequent cmd
with another 20s timeout will cascade resulting in unnecessary
traces and/or NMI Lockups.

Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-09-22 13:57:32 -04:00
Selvin Xavier
f218d67ef0 RDMA/bnxt_re: Allow posting when QPs are in error
This  patch allows driver to post send and receive
requests on QPs which are in  error state.

Instead of flushing the QP in the context of polling
error CQEs, the QPs will be added to a flush list
maintained per CQ. QP state is moved to error.
QP is added to flush list if the user moves it
to error state using modify_qp also. After polling the HW
CQ in poll_cq routine, this flush list is traversed
and driver completes work requests on each QP in the flush
list, till the budget expires. The QP is moved out of
flush list during QP destroy or during modify_QP to RESET.

When ULPs post Work Requests while QP is in error state,
driver will store the ULP data and then increment the
QP producer s/w index, without ringing doorbell. It then
schedules a worker to invoke the CQ handler since the
interrupts wont be generated from the HW for this request.

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-07-24 08:45:12 -04:00
Devesh Sharma
cc1ec769b8 RDMA/bnxt_re: Fixing the Control path command and response handling
Fixing a concurrency issue with creq handling. Each caller
was given a globally managed crsq element, which was
accessed outside a lock. This could result in corruption,
if lot of applications are simultaneously issuing Control Path
commands. Now, each caller will provide its own response buffer
and the responses will be copied under a lock.
Also, Fixing the queue full condition check for the CMDQ.

As a part of these changes, the control path code is refactored
to remove the code replication in the response status checking.

Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-06-13 16:09:04 -04:00
Selvin Xavier
1ac5a40479 RDMA/bnxt_re: Add bnxt_re RoCE driver
This patch introduces the RoCE driver for the Broadcom
NetXtreme-E 10/25/40/50G RoCE HCAs.

The RoCE driver is a two part driver that relies on the parent
bnxt_en NIC driver to operate.  The changes needed in the bnxt_en
driver have already been incorporated via Dave Miller's net tree
into the mainline kernel.

The vendor official git repository for this driver is available
on github as:
https://github.com/Broadcom/linux-rdma-nxt/

Signed-off-by: Eddie Wai <eddie.wai@broadcom.com>
Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-02-14 09:51:15 -05:00