Commit Graph

35 Commits

Author SHA1 Message Date
Hariprasad S 3661df179b iw_cxgb4: gracefully handle unknown CQE status errors
c4iw_poll_cq_on() shouldn't fail the poll operation just because
the CQE status is unknown.  Rather, it should map this to the
"fatal error" status and log the anomaly.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-07-28 11:24:51 -04:00
Matan Barak bcf4c1ea58 IB/core: Change provider's API of create_cq to be extendible
Add a new ib_cq_init_attr structure which contains the
previous cqe (minimum number of CQ entries) and comp_vector
(completion vector) in addition to a new flags field.
All vendors' create_cq callbacks are changed in order
to work with the new API.

This commit does not change any functionality.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-By: Devesh Sharma <devesh.sharma@avagotech.com> to patch #2
Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-06-12 14:49:10 -04:00
Hariprasad S 74217d4c6a iw_cxgb4: support for bar2 qid densities exceeding the page size
Handle this configuration:

        Queues Per Page * SGE BAR2 Queue Register Area Size > Page Size

Use cxgb4_bar2_sge_qregs() to obtain the proper location within the
bar2 region for a given qid.

Rework the DB and GTS write functions to make use of this bar2 info.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-06-11 12:22:32 -04:00
Hariprasad S 09ece8b9e9 iw_cxgb4: use BAR2 GTS register for T5 kernel mode CQs
For T5, we must not use the kdb/kgts registers, in order avoid db drops
under extreme loads.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-05-05 09:18:01 -04:00
Hariprasad S 6198dd8d7a iw_cxgb4: 32b platform fixes
- get_dma_mr() was using ~0UL which is should be ~0ULL.  This causes the
DMA MR to get setup incorrectly in hardware.

- wr_log_show() needed a 64b divide function div64_u64() instead of
  doing
division directly.

- fixed warnings about recasting a pointer to a u64

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-05-05 09:18:01 -04:00
Hariprasad Shenai cf7fe64aee 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>
2015-01-16 01:07:02 -05:00
Hariprasad Shenai a56c66e808 iw_cxgb4: Cleanup register defines/MACROS defined in t4.h
Cleanup all the MACROS defined in t4.h and the affected files

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-16 01:07:01 -05:00
Hariprasad Shenai e2ac962895 cxgb4: Cleanup macros so they follow the same style and look consistent, part 2
Various patches have ended up changing the style of the symbolic macros/register
defines to different style.

As a result, the current kernel.org files are a mix of different macro styles.
Since this macro/register defines is used by different drivers a
few patch series have ended up adding duplicate macro/register define entries
with different styles. This makes these register define/macro files a complete
mess and we want to make them clean and consistent. This patch cleans up a part
of it.

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-10 12:57:10 -05:00
Hariprasad Shenai 66eb19af0b iw_cxgb4: advertise the correct device max attributes
Advertise the actual max limits for things like qp depths, number of
qps, cqs, etc.

Clean up the queue allocation for qps and cqs.

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>
2014-07-21 20:23:59 -07:00
Hariprasad Shenai 7730b4c7e3 cxgb4/iw_cxgb4: work request logging feature
This commit enhances the iwarp driver to optionally keep a log of rdma
work request timining data for kernel mode QPs.  If iw_cxgb4 module option
c4iw_wr_log is set to non-zero, each work request is tracked and timing
data maintained in a rolling log that is 4096 entries deep by default.
Module option c4iw_wr_log_size_order allows specifing a log2 size to use
instead of the default order of 12 (4096 entries). Both module options
are read-only and must be passed in at module load time to set them. IE:

modprobe iw_cxgb4 c4iw_wr_log=1 c4iw_wr_log_size_order=10

The timing data is viewable via the iw_cxgb4 debugfs file "wr_log".
Writing anything to this file will clear all the timing data.
Data tracked includes:

- The host time when the work request was posted, just before ringing
the doorbell.  The host time when the completion was polled by the
application.  This is also the time the log entry is created.  The delta
of these two times is the amount of time took processing the work request.

- The qid of the EQ used to post the work request.

- The work request opcode.

- The cqe wr_id field.  For sq completions requests this is the swsqe
index.  For recv completions this is the MSN of the ingress SEND.
This value can be used to match log entries from this log with firmware
flowc event entries.

- The sge timestamp value just before ringing the doorbell when
posting,  the sge timestamp value just after polling the completion,
and CQE.timestamp field from the completion itself.  With these three
timestamps we can track the latency from post to poll, and the amount
of time the completion resided in the CQ before being reaped by the
application.  With debug firmware, the sge timestamp is also logged by
firmware in its flowc history so that we can compute the latency from
posting the work request until the firmware sees it.

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>
2014-07-15 16:25:16 -07:00
Hariprasad Shenai 04e10e2164 iw_cxgb4: Detect Ing. Padding Boundary at run-time
Updates iw_cxgb4 to determine the Ingress Padding Boundary from
cxgb4_lld_info, and take subsequent actions.

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>
2014-07-15 16:25:16 -07:00
Linus Torvalds f9da455b93 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Seccomp BPF filters can now be JIT'd, from Alexei Starovoitov.

 2) Multiqueue support in xen-netback and xen-netfront, from Andrew J
    Benniston.

 3) Allow tweaking of aggregation settings in cdc_ncm driver, from Bjørn
    Mork.

 4) BPF now has a "random" opcode, from Chema Gonzalez.

 5) Add more BPF documentation and improve test framework, from Daniel
    Borkmann.

 6) Support TCP fastopen over ipv6, from Daniel Lee.

 7) Add software TSO helper functions and use them to support software
    TSO in mvneta and mv643xx_eth drivers.  From Ezequiel Garcia.

 8) Support software TSO in fec driver too, from Nimrod Andy.

 9) Add Broadcom SYSTEMPORT driver, from Florian Fainelli.

10) Handle broadcasts more gracefully over macvlan when there are large
    numbers of interfaces configured, from Herbert Xu.

11) Allow more control over fwmark used for non-socket based responses,
    from Lorenzo Colitti.

12) Do TCP congestion window limiting based upon measurements, from Neal
    Cardwell.

13) Support busy polling in SCTP, from Neal Horman.

14) Allow RSS key to be configured via ethtool, from Venkata Duvvuru.

15) Bridge promisc mode handling improvements from Vlad Yasevich.

16) Don't use inetpeer entries to implement ID generation any more, it
    performs poorly, from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1522 commits)
  rtnetlink: fix userspace API breakage for iproute2 < v3.9.0
  tcp: fixing TLP's FIN recovery
  net: fec: Add software TSO support
  net: fec: Add Scatter/gather support
  net: fec: Increase buffer descriptor entry number
  net: fec: Factorize feature setting
  net: fec: Enable IP header hardware checksum
  net: fec: Factorize the .xmit transmit function
  bridge: fix compile error when compiling without IPv6 support
  bridge: fix smatch warning / potential null pointer dereference
  via-rhine: fix full-duplex with autoneg disable
  bnx2x: Enlarge the dorq threshold for VFs
  bnx2x: Check for UNDI in uncommon branch
  bnx2x: Fix 1G-baseT link
  bnx2x: Fix link for KR with swapped polarity lane
  sctp: Fix sk_ack_backlog wrap-around problem
  net/core: Add VF link state control policy
  net/fsl: xgmac_mdio is dependent on OF_MDIO
  net/fsl: Make xgmac_mdio read error message useful
  net_sched: drr: warn when qdisc is not work conserving
  ...
2014-06-12 14:27:40 -07:00
Hariprasad Shenai cf38be6d61 iw_cxgb4: Allocate and use IQs specifically for indirect interrupts
Currently indirect interrupts for RDMA CQs funnel through the LLD's RDMA
RXQs, which also handle direct interrupts for offload CPLs during RDMA
connection setup/teardown.  The intended T4 usage model, however, is to
have indirect interrupts flow through dedicated IQs. IE not to mix
indirect interrupts with CPL messages in an IQ.  This patch adds the
concept of RDMA concentrator IQs, or CIQs, setup and maintained by the
LLD and exported to iw_cxgb4 for use when creating CQs. RDMA CPLs will
flow through the LLD's RDMA RXQs, and CQ interrupts flow through the
CIQs.

Design:

cxgb4 creates and exports an array of CIQs for the RDMA ULD.  These IQs
are sized according to the max available CQs available at adapter init.
In addition, these IQs don't need FL buffers since they only service
indirect interrupts.  One CIQ is setup per RX channel similar to the
RDMA RXQs.

iw_cxgb4 will utilize these CIQs based on the vector value passed into
create_cq().  The num_comp_vectors advertised by iw_cxgb4 will be the
number of CIQs configured, and thus the vector value will be the index
into the array of CIQs.

Based on original work by Steve Wise <swise@opengridcomputing.com>

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>
2014-06-10 22:49:54 -07:00
Yann Droneaud b6f04d3d21 RDMA/cxgb4: Add missing padding at end of struct c4iw_create_cq_resp
The i386 ABI disagrees with most other ABIs regarding alignment of
data types larger than 4 bytes: on most ABIs a padding must be added
at end of the structures, while it is not required on i386.

So for most ABI struct c4iw_create_cq_resp gets implicitly padded
to be aligned on a 8 bytes multiple, while for i386, such padding
is not added.

The tool pahole can be used to find such implicit padding:

  $ pahole --anon_include \
           --nested_anon_include \
           --recursive \
           --class_name c4iw_create_cq_resp \
           drivers/infiniband/hw/cxgb4/iw_cxgb4.o

Then, structure layout can be compared between i386 and x86_64:

  +++ obj-i386/drivers/infiniband/hw/cxgb4/iw_cxgb4.o.pahole.txt   2014-03-28 11:43:05.547432195 +0100
  --- obj-x86_64/drivers/infiniband/hw/cxgb4/iw_cxgb4.o.pahole.txt 2014-03-28 10:55:10.990133017 +0100
  @@ -14,9 +13,8 @@ struct c4iw_create_cq_resp {
          __u32                      size;                 /*    28     4 */
          __u32                      qid_mask;             /*    32     4 */

  -       /* size: 36, cachelines: 1, members: 6 */
  -       /* last cacheline: 36 bytes */
  +       /* size: 40, cachelines: 1, members: 6 */
  +       /* padding: 4 */
  +       /* last cacheline: 40 bytes */
   };

This ABI disagreement will make an x86_64 kernel try to write past the
buffer provided by an i386 binary.

When boundary check will be implemented, the x86_64 kernel will refuse
to write past the i386 userspace provided buffer and the uverbs will
fail.

If the structure is on a page boundary and the next page is not
mapped, ib_copy_to_udata() will fail and the uverb will fail.

This patch adds an explicit padding at end of structure
c4iw_create_cq_resp, and, like 92b0ca7cb1 ("IB/mlx5: Fix stack info
leak in mlx5_ib_alloc_ucontext()"), makes function c4iw_create_cq()
not writting this padding field to userspace. This way, x86_64 kernel
will be able to write struct c4iw_create_cq_resp as expected by
unpatched and patched i386 libcxgb4.

Link: http://marc.info/?i=cover.1399309513.git.ydroneaud@opteya.com
Cc: <stable@vger.kernel.org>
Fixes: cfdda9d764 ("RDMA/cxgb4: Add driver for Chelsio T4 RNIC")
Fixes: e24a72a330 ("RDMA/cxgb4: Fix four byte info leak in c4iw_create_cq()")
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-05-29 21:44:57 -07:00
Steve Wise 97df1c6736 RDMA/cxgb4: Use uninitialized_var()
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-04-11 11:36:10 -07:00
Steve Wise b4e2901c52 RDMA/cxgb4: SQ flush fix
There is a race when moving a QP from RTS->CLOSING where a SQ work
request could be posted after the FW receives the RDMA_RI/FINI WR.
The SQ work request will never get processed, and should be completed
with FLUSHED status.  Function c4iw_flush_sq(), however was dropping
the oldest SQ work request when in CLOSING or IDLE states, instead of
completing the pending work request. If that oldest pending work
request was actually complete and has a CQE in the CQ, then when that
CQE is proceessed in poll_cq, we'll BUG_ON() due to the inconsistent
SQ/CQ state.

This is a very small timing hole and has only been hit once so far.

The fix is two-fold:

1) c4iw_flush_sq() MUST always flush all non-completed WRs with FLUSHED
   status regardless of the QP state.

2) In c4iw_modify_rc_qp(), always set the "in error" bit on the queue
   before moving the state out of RTS.  This ensures that the state
   transition will not happen while another thread is in
   post_rc_send(), because set_state() and post_rc_send() both aquire
   the qp spinlock.  Also, once we transition the state out of RTS,
   subsequent calls to post_rc_send() will fail because the "in error"
   bit is set.  I don't think this fully closes the race where the FW
   can get a FINI followed a SQ work request being posted (because
   they are posted to differente EQs), but the #1 fix will handle the
   issue by flushing the SQ work request.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-04-11 11:36:08 -07:00
Steve Wise 70b9c66053 RDMA/cxgb4: Ignore read reponse type 1 CQEs
These are generated by HW in some error cases and need to be
silently discarded.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-24 10:07:35 -07:00
Steve Wise 8a9c399eee RDMA/cxgb4: Fix incorrect BUG_ON conditions
Based on original work from Jay Hernandez <jay@chelsio.com>

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-20 10:01:30 -07:00
Steve Wise ffd435924c RDMA/cxgb4: Cap CQ size at T4_MAX_IQ_SIZE
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-20 09:59:04 -07:00
Dan Carpenter e24a72a330 RDMA/cxgb4: Fix four byte info leak in c4iw_create_cq()
There is a four byte hole at the end of the "uresp" struct after the
->qid_mask member.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-20 09:59:04 -07:00
Steve Wise 27ca34f54a RDMA/cxgb4: Fix accounting for unsignaled SQ WRs to deal with wrap
When determining how many WRs are completed with a signaled CQE,
correctly deal with queue wraps.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-08-13 11:55:46 -07:00
Steve Wise 1cf24dcef4 RDMA/cxgb4: Fix QP flush logic
This patch makes following fixes in QP flush logic:

- correctly flushes unsignaled WRs followed by a signaled WR
- supports for flushing a CQ bound to multiple QPs
- resets cidx_flush if a active queue starts getting HW CQEs again
- marks WQ in error when we leave RTS. This was only being done for
  user queues, but we need it for kernel queues too so that
  post_send/post_recv will start returning the appropriate error
  synchronously
- eats unsignaled read resp CQEs. HW always inserts CQEs so we must
  silently discard them if the read work request was unsignaled.
- handles QP flushes with pending SW CQEs. The flush and out of order
  completion logic has a bug where if out of order completions are
  flushed but not yet polled by the consumer and the qp is then
  flushed then we end up inserting duplicate completions.
- c4iw_flush_sq() should only flush wrs that have not already been
  flushed.  Since we already track where in the SQ we've flushed via
  sq.cidx_flush, just start at that point and flush any remaining.
  This bug only caused a problem in the presence of unsignaled work
  requests.

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

[ Fixed sparse warning due to htonl/ntohl confusion.  - Roland ]

Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-08-13 11:55:45 -07:00
Jonathan Lallinger c34c97ad8c RDMA/cxgb4: Fix iw_cxgb4 count_rcqes() logic
Fix another place in the code where logic dealing with the t4_cqe was
using the wrong QID.  This fixes the counting logic so that it tests
against the SQ QID instead of the RQ QID when counting RCQES.

Signed-off by: Jonathan Lallinger <jonathan@ogc.us>
Signed-off by: Steve Wise <swise@ogc.us>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-11-28 11:53:05 -08:00
Kumar Sanghvi 581bbe2cd0 RDMA/cxgb4: Serialize calls to CQ's comp_handler
Commit 01e7da6ba5 ("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>
2011-10-31 11:34:53 -07:00
Jonathan Lallinger e14d62c05c RDMA/cxgb4: Use correct QID in insert_recv_cqe()
When creating flushed receive CQEs, set the QPID field in the t4_cqe
to the SQ QID and not the RQ QID.  Otherwise the poll code will not
find the correct QP context.

Signed-off by: Jonathan Lallinger <jonathan@ogc.us>
Signed-off by: Steve Wise <swise@ogc.us>

Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-10-14 14:23:40 -07:00
Steve Wise 2ff7d09a1b RDMA/cxgb4: Don't exceed hw IQ depth limit for user CQs
Memory allocated for user CQs gets rounded up to the next page
boundary.  And after rounding, we recalculate the resulting IQ depth
and we need to make sure we don't exceed the HW limits.

This bug can result a much smaller CQ allocated than was expected if
the HW size field is exceeded, resulting in CQ overflow failures.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-06-17 11:52:45 -07:00
Steve Wise aadc4df308 RDMA/cxgb4: Centralize the wait logic
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-09-28 10:46:34 -07:00
Steve Wise 6ff0e343b3 RDMA/cxgb4: Ignore TERMINATE CQEs
T4 incorrectly inserts TERM CQEs into the CQ.  Silently ignore them.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-09-28 10:46:31 -07:00
Roland Dreier c8e081a1bf RDMA/cxgb4: Fix warnings about casts to/from pointers of different sizes
Fix:

  drivers/infiniband/hw/cxgb4/qp.c: In function ‘create_qp’:
  drivers/infiniband/hw/cxgb4/qp.c:147: warning: cast from pointer to integer of different size
  drivers/infiniband/hw/cxgb4/qp.c: In function ‘rdma_fini’:
  drivers/infiniband/hw/cxgb4/qp.c:988: warning: cast from pointer to integer of different size
  drivers/infiniband/hw/cxgb4/qp.c: In function ‘rdma_init’:
  drivers/infiniband/hw/cxgb4/qp.c:1063: warning: cast from pointer to integer of different size
  drivers/infiniband/hw/cxgb4/mem.c: In function ‘write_adapter_mem’:
  drivers/infiniband/hw/cxgb4/mem.c:74: warning: cast from pointer to integer of different size
  drivers/infiniband/hw/cxgb4/cq.c: In function ‘destroy_cq’:
  drivers/infiniband/hw/cxgb4/cq.c:58: warning: cast from pointer to integer of different size
  drivers/infiniband/hw/cxgb4/cq.c: In function ‘create_cq’:
  drivers/infiniband/hw/cxgb4/cq.c:135: warning: cast from pointer to integer of different size
  drivers/infiniband/hw/cxgb4/cm.c: In function ‘fw6_msg’:
  drivers/infiniband/hw/cxgb4/cm.c:2326: warning: cast to pointer from integer of different size

by casting pointers to unsigned long instead of u64.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-09-27 17:51:04 -07:00
David Rientjes d3c814e8b2 RDMA/cxgb4: Remove dependency on __GFP_NOFAIL
The alloc_skb() in various allocations are failable, so remove
__GFP_NOFAIL from their masks.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-07-21 10:55:05 -07:00
Steve Wise 1973e8b8ed RDMA/cxgb4: Avoid false GTS CIDX_INC overflows
The T4 IQ hw design assumes CIDX_INC credits will be returned on a
regular basis and always before the CIDX counter crosses over the PIDX
counter.  For RDMA CQs, however, returning CIDX_INC credits is only
needed and desired when and if the CQ is armed for notification.  This
can lead to a GTS write returning credits that causes the HW to reject
the credit update because it causes CIDX to pass PIDX.  Once this
happens, the CIDX/PIDX counters get out of whack and an application
can miss a notification and get stuck blocked awaiting a notification.

To avoid this, we allocate the HW IQ 2x times the requested size.
This seems to avoid the false overflow failures.  If we see more
issues with this, then we'll have to add code in the poll path to
return credits periodically like when the amount reaches 1/2 the queue
depth).  I would like to avoid this as it adds a PCI write transaction
for applications that never arm the CQ (like most MPIs).

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-07-06 14:04:04 -07:00
FUJITA Tomonori f38926aa1d RDMA/cxgb4: Use the DMA state API instead of the pci equivalents
This replace the PCI DMA state API (include/linux/pci-dma.h) with the
DMA equivalents since the PCI DMA state API will be obsolete.

No functional change.

For further information about the background:

http://marc.info/?l=linux-netdev&m=127037540020276&w=2

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-07-06 14:01:42 -07:00
Steve Wise 84172dee05 RDMA/cxgb4: Optimize CQ overflow detection
1) save the timestamp flit in the cq when we consume a CQE.

2) always compare the saved flit with the previous entry flit when
   reading the next CQE entry.  If the flits don't compare, then we
   have overflowed.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-05-24 21:08:01 -07:00
Steve Wise 895cf5f3d6 RDMA/cxgb4: CQ size must be IQ size - 2
We need 1 extra entry for the status page and 1 to always have 1 free
entry to detect when the queue is full.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-05-24 21:08:00 -07:00
Steve Wise cfdda9d764 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>
2010-04-21 15:30:06 -07:00