* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
IB/mad: Fix kernel crash when .process_mad() returns SUCCESS|CONSUMED
IPoIB: Test for NULL broadcast object in ipiob_mcast_join_finish()
MAINTAINERS: Add cxgb3 and iw_cxgb3 NIC and iWARP driver entries
IB/mlx4: Fix creation of kernel QP with max number of send s/g entries
IB/mthca: Fix max_sge value returned by query_device
RDMA/cxgb3: Fix uninitialized variable warning in iwch_post_send()
IB/mlx4: Fix uninitialized-var warning in mlx4_ib_post_send()
IB/ipath: Fix UC receive completion opcode for RDMA WRITE with immediate
IB/ipath: Fix printk format for ipath_sdma_status
If a low-level driver returns IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED,
handle_outgoing_dr_smp() doesn't clean up properly. The fix is to
kfree the local data and break, rather than falling through. This was
observed with the ipath driver, but could happen with any driver.
This fixes <https://bugs.openfabrics.org/show_bug.cgi?id=1027>.
Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
We saw a kernel oops in our regression testing when a multicast "join
finish" occurred just after the interface was -- this is
<https://bugs.openfabrics.org/show_bug.cgi?id=1040>. The test
randomly causes the HCA physical port to go down then up.
The cause of this is that ipoib_mcast_join_finish() processing happen
just after ipoib_mcast_dev_flush() was invoked (in which case the
broadcast pointer is NULL). This patch tests for and handles the case
where priv->broadcast is NULL.
Cc: <stable@kernel.org>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
When creating a kernel QP where the consumer asked for a send queue
with lots of scatter/gater entries, set_kernel_sq_size() incorrectly
returned an error if the send queue stride is larger than the
hardware's maximum send work request descriptor size. This is not a
problem; the only issue is to make sure that the actual descriptors
used do not overflow the maximum descriptor size, so check this instead.
Clamp the returned max_send_sge value to be no bigger than what
query_device returns for the max_sge to avoid confusing hapless users,
even if the hardware is capable of handling a few more s/g entries.
This bug caused NFS/RDMA mounts to fail when the server adapter used
the mlx4 driver.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.
This patch fixes the problem by using the new function,
device_create_drvdata().
Cc: Kay Sievers <kay.sievers@vrfy.org>
Reviewed-by: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The mthca driver returns the maximum number of scatter/gather entries
returned by the firmware as the max_sge value when device properties
are queried. However, the firmware also reports a limit on the
maximum descriptor size allowed, and because mthca takes into account
the worst case send request overhead when checking whether to allow a
QP to be created, the largest number of scatter/gather entries that
can be used with mthca may be limited by the maximum descriptor size
rather than just by the actual s/g entry limit.
This means that applications cannot actually create QPs with
max_send_sge equal to the limit returned by ib_query_device(). Fix
this by checking if the maximum descriptor size imposes a lower limit
and if so returning that lower limit.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
drivers/infiniband/hw/cxgb3/iwch_qp.c: In function 'iwch_post_send':
drivers/infiniband/hw/cxgb3/iwch_qp.c:232: warning: 't3_wr_flit_cnt' may be used uninitialized in this function
This is what akpm describes as "the dopey
gcc-doesn't-know-that-foo(&var)-writes-to-var problem."
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Acked-by: Steve Wise <swise@opengridcomputing.com>
drivers/infiniband/hw/mlx4/qp.c: In function 'mlx4_ib_post_send':
drivers/infiniband/hw/mlx4/qp.c:1460: warning: 'seglen' may be used uninitialized in this function
This is the dopey gcc-doesn't-know-that-foo(&var)-writes-to-var problem.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
When I fixed the RC receive completion opcode in 2bfc8e9e ("IB/ipath:
Return the correct opcode for RDMA WRITE with immediate"), I forgot to
fix UC, which had the same problem for RDMA write with immediate
returning the wrong opcode.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Commit f018c7e1 ("IB/ipath: Change ipath_devdata.ipath_sdma_status to be
unsigned long") changed ipath_sdma_status to be unsigned long, but left
a few debug messages that printed it out with a %016llx format, which
generates the warnings
drivers/infiniband/hw/ipath/ipath_sdma.c:348: warning: format '%016llx' expects type 'long long unsigned int', but argument 3 has type 'long unsigned int'
drivers/infiniband/hw/ipath/ipath_sdma.c:618: warning: format '%016llx' expects type 'long long unsigned int', but argument 3 has type 'long unsigned int'
Fix this by changing the format used to print out the value to %08lx
(8 hex digits are now sufficient, because the highest bit used is 31).
Warnings reported by Randy Dunlap <randy.dunlap@oracle.com>.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
cxio_flush_sq() was failing to wrap around the software send queue
causing garbage completion entries on a flush operation.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Andrew Morton <akpm@linux-foundation.org> pointed out that bitops
should take an unsigned long * arg. However, the ipath driver was
doing bitops on struct ipath_devdata.ipath_sdma_status, which is u64.
Change this member to unsigned long to avoid tons of warnings when x86
fixes the bitops to take unsigned long * instead of void *.
Also, change the IPATH_SDMA_RUNNING and IPATH_SDMA_SHUTDOWN bit
numbers to 30 and 31 (instead of 62 and 63) so that we're not setting
another booby trap for someone who tries to make ipath work on a
32-bit architecture.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The official reason is "with the presence of pid namespaces in the
kernel using pid_t-s inside one is no longer safe."
But the reason I fix this right now is the following:
About a month ago (when 2.6.25 was not yet released) there still was a
one last caller of a to-be-deprecated-soon function find_pid() - the
kill_proc() function, which in turn was only used by nfs callback
code.
During the last merge window, this last caller was finally eliminated
by some NFS patch(es) and I was about to finally kill this kill_proc()
and find_pid(), but found, that I was late and the kill_proc is now
called from the ipath driver since commit 58411d1c ("IB/ipath: Head of
Line blocking vs forward progress of user apps").
So here's a patch that fixes this code to use struct pid * and (!)
the kill_pid routine.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
If an out of sequence RDMA read response middle or last packet is
received, we should only resend the RDMA read request on the first
out of sequence packet and drop subsequent out of sequence packets
otherwise, we get "too many retries".
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The send DMA hardware queue voided a number of prior assumptions about
when a send is complete which led to completions being generated out of
order. There were also a number of locking issues when switching the QP
to the error or reset states, and we implement the IB_QPS_SQD state.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
When errors are detected in RC, the QP should transition to the
IB_QPS_ERR state, not the IB_QPS_SQE state. Also, when the error is on
the responder side, the receive work completion error was incorrect
(remote vs. local).
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Fix some bugs with the max_aggr module parameter added with LRO support:
- The module parameter value ignored and not actually used to set
lro_mgr.max_aggr.
- MODULE_PARM_DESC had a typo "_mro_" instead of "_lro_" so it didn't
end up describing the actual module parameter.
- The nes_lro_max_aggr variable was declared as unsigned, but the
module_param line said "int" instead of "uint" for the type.
- The default value for the parameter was stuck in the permissions
field of module_param, which led to nonsensical permissions for the
file under /sys/module/iw_nes/param.
- The parameter was used in only one file but defined in another, which
led to the variable being global for no good reason. Move everything
related to the parameter to the file nes_hw.c where it is actually
used.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This is necessary because, in a multicore environment, a race between
uverbs async handler and destroy QP could occur.
Signed-off-by: Stefan Roscher <stefan.roscher at de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
What's fixed:
in ipath_cancel_sends()
We need to unconditionally set ABORTING. So, swap the tests
so the set_bit() isn't shadowed by the &&.
If we've disarmed the piobufs, then we need to unconditionally
set DISARMED. So, move it out from the overly protective if
at the bottom.
in sdma_abort_task()
Abort_task was written knowing that the SDMA engine would always
be reset (and restarted) on error. A recent change broke that
fundamental assumption by taking the restart portion and making
it conditional on a link status change. But, SDMA can go boom
without a link status change in some conditions.
Signed-off-by: John Gregor <john.gregor@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Now that we always use PIO for vl15 on 7220, we could get stuck forever
if we happened to run out of PIO buffers from the verbs code, because
the setup code wouldn't run; the interrupt was also ignored if SDMA was
supported. We also have to reduce the pio update threshold if we have
fewer kernel buffers than the existing threshold.
Clean up the initialization a bit to get ordering safer and more
sensible, and use the existing ipath_chg_kernavail call to do init,
rather than doing it separately.
Drop unnecessary clearing of pio buffer on pio parity error.
Drop incorrect updating of pioavailshadow when exitting freeze mode
(software state may not match chip state if buffer has been allocated
and not yet written).
If we couldn't get a kernel buffer for a while, make sure we are
in sync with hardware, mainly to handle the exitting freeze case.
Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The loop in ipath_kreceive() that processes packets increments the
loop-index 'i' once too often, because the exit condition does not
depend on it, and is checked after the increment. By adding a check for
!last to the iterator in the for loop, we correct that in a way that is
not so likely to be re-broken by changes in the loop body.
Signed-off-by: Michael Albaugh <micheal.albaugh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This patch fixes a bug in the RC responder which generates a completion
entry with the wrong opcode when an RDMA WRITE with immediate is received.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The semantics of cancel_sends changed, but the code using it was missed.
Don't leave sends and pioavail updates disabled, and add a comment as to
why the force update is needed.
Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
If a send work request has immediate errors and is not put on the
send queue, we shouldn't update any of the QP state.
The increment of the SSN wasn't obeying this.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
We warn about prototype chips, but the function that checks for
support is also called as a result of a get_portinfo request, which
can clutter the logs.
Restrict warning to only appear during initialization.
Signed-off-by: Michael Albaugh <michael.albaugh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Currently, iw_cxgb3 is severely limited on the amount of userspace
memory that can be registered in in a single memory region, which
causes big problems for applications that expect to be able to
register 100s of MB.
The problem is that the driver uses a single kmalloc()ed buffer to
hold the physical buffer list (PBL) for the entire memory region
during registration, which means that 8 bytes of contiguous memory are
required for each page of memory being registered. For example, a 64
MB registration will require 128 KB of contiguous memory with 4 KB
pages, and it unlikely that such an allocation will succeed on a busy
system.
This is purely a driver problem: the temporary page list buffer is not
needed by the hardware, so we can fix this by writing the PBL to the
hardware in page-sized chunks rather than all at once. We do this by
splitting the memory registration operation up into several steps:
- Allocate PBL space in adapter memory for the full registration
- Copy PBL to adapter memory in chunks
- Allocate STag and enable memory region
This also allows several other cleanups to the __cxio_tpt_op()
interface and related parts of the driver.
This change leaves the reregister memory region and memory window
operations broken, but they already didn't work due to other
longstanding bugs, so fixing them will be left to a later patch.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Current iw_cxgb3 code adds PBL memory to the driver's gen_pool in 2 MB
chunks. This limits the largest single allocation that can be done to
the same size, which means that with 4 KB pages, each of which takes 8
bytes of PBL memory, the largest memory region that can be allocated
is 1 GB (256K PBL entries * 4 KB/entry).
Remove this limit by adding all the PBL memory in a single gen_pool
chunk, if possible. Add code that falls back to smaller chunks if
gen_pool_add() fails, which can happen if there is not sufficient
contiguous lowmem for the internal gen_pool bitmap.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Also remove duplicate assignment of local_ca_ack_delay and change
min_t check for local_ca_ack_delay to u8 instead of int.
Signed-off-by: Stefan Roscher <stefan.roscher at de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Testing on large clusters shows its way too short at 10 secs.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Remove bad BUG_ON() that can trigger in correct operation from
close_con_rpl(). It is possible to get a close_rpl message on a dead
connection. The sequence is:
- host refs ep for close exchange
- host posts close_req
- hw posts PEER_ABORT from incoming RST
- host marks ep DEAD
- host posts ABORT_RPL and releases ep resources
- hw posts CLOSE_RPL
- host derefs ep and ep freed.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
- Flush the QP only after the HW disables the connection. Currently
we flush the QP when transitioning to CLOSING. This exposes a race
condition where the HW can complete a RECV WR, for instance, -and-
the SW can flush that same WR.
- Only call CQ event handlers on flush IFF we actually flushed something.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Commit f56bcd80 ("IPoIB: Use separate CQ for UD send completions")
introduced a bug where the transmit queue could get stopped and never
woken up. The problem is that send completions are only polled at the
end of the xmit function, so if the send queue fills up and the xmit
path stops the queue, then there is no way for send completions to
ever get polled, and so the transmit queue stays stopped forever.
Fix this by arming the send CQ just before posting the last send
request that fills the send queue. Then, when the completion event
handler is called, drain the send CQ. Since it is possible that not
enough send completions are in the CQ, verify that the the net queue
has been woken up after draining the send CQ, and if not arm a timer
and drain again at the timer function.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
When I merged bbf8eed1 ("IB/mlx4: Add support for resizing CQs") I
changed things around so that mlx4_ib_alloc_cq_buf() and
mlx4_ib_free_cq_buf() were used everywhere they could be. However, I
screwed up the number of entries passed into mlx4_ib_alloc_cq_buf()
in a couple places -- the function bumps the number of entries
internally, so the caller shouldn't add 1 as well.
Passing a too-big value for the number of entries to mlx4_ib_free_cq_buf()
can cause the cleanup to go off the end of an array and corrupt
allocator state in interesting ways.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Various cleanups:
- Change // to /* .. */
- Place whitespace around binary operators.
- Trim down a few long lines.
- Some minor alignment formatting for better readability.
- Remove some silly tabs.
Signed-off-by: Glenn Streiff <gstreiff@neteffect.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This patch enables the iw_nes module for NetEffect RNICs to support
additional PHYs including SFP+ (referred to as ARGUS in the code).
Signed-off-by: Eric Schneider <eric.schneider@neteffect.com>
Signed-off-by: Glenn Streiff <gstreiff@neteffect.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
When creating a child interface, copy the MTU information from the
parent. Otherwise when the child's multicast join completes, the MTU
will not be updated since the code does
dev->mtu = min(priv->mcast_mtu, priv->admin_mtu);
and priv->admin_mtu will be set to 0.
Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Commit cb9fbc5c ("IB: expand ib_umem_get() prototype") changed the
mthca userspace ABI to provide a way for userspace to indicate which
memory regions need the DMA write barrier attribute. However, it is
possible to handle this without breaking existing userspace, by having
the mthca kernel driver recognize whether it is talking to old or new
userspace, depending on the size of the register MR structure passed in.
The only potential drawback of this is that is allows old userspace
(which has a bug with DMA ordering on large SGI Altix systems) to
continue to run on new kernels, but the advantage of allowing old
userspace to continue to work on unaffected systems seems to outweigh
this, and we can print a warning to push people to upgrade their
userspace.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
When a FMR is unmapped, mthca resets the map count to 0, and clears
the upper part of the R_Key which is used as the sequence counter.
This poses a problem for RDS, which uses ib_fmr_unmap as a fence
operation. RDS assumes that after issuing an unmap, the old R_Keys
will be invalid for a "reasonable" period of time. For instance,
Oracle processes uses shared memory buffers allocated from a pool of
buffers. When a process dies, we want to reclaim these buffers -- but
we must make sure there are no pending RDMA operations to/from those
buffers. The only way to achieve that is by using unmap and sync the
TPT.
However, when the sequence count is reset on unmap, there is a high
likelihood that a new mapping will be given the same R_Key that was
issued a few milliseconds ago.
To prevent this, don't reset the sequence count when unmapping a FMR.
Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
If a lot of QPs fall into Error state at once and the EQ of the
respective HCA is too small, it might overrun, causing the eHCA driver
to stop processing completion events and calling the application's
completion handlers, effectively causing traffic to stop.
Fix this by limiting available QPs and CQs to a customizable max
count, and determining EQ size based on these counts and a worst-case
assumption.
Signed-off-by: Stefan Roscher <stefan.roscher@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Use a dedicated CQ for UD send completions. Also, do not arm the UD
send CQ, which reduces the number of interrupts generated. This patch
farther reduces overhead by not calling poll CQ for every posted send
WR -- it does polls only when there 16 or more outstanding work requests.
Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Count FMR alignment violations per session as part of the iscsi
statistics.
Signed-off-by: Eli Dorfman <elid@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
ehca_create_eq() was assigning a signed return value to an unsiged
local variable and then checking if the variable was < 0, which meant
that errors were always ignored. Fix this by using one variable for
signed integer return values and another for u64 hcall return values.
Bug originally found by Roel Kluin <12o3l@tiscali.nl>.
Signed-off-by: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Open MPI, Intel MPI and other applications don't respect the iWARP
requirement that the client (active) side of the connection send the
first RDMA message. This class of application connection setup is
called peer-to-peer. Typically once the connection is setup, _both_
sides want to send data.
This patch enables supporting peer-to-peer over the chelsio RNIC by
enforcing this iWARP requirement in the driver itself as part of RDMA
connection setup.
Connection setup is extended, when the peer2peer module option is 1,
such that the MPA initiator will send a 0B Read (the RTR) just after
connection setup. The MPA responder will suspend SQ processing until
the RTR message is received and reply-to.
In the longer term, this will be handled in a standardized way by
enhancing the MPA negotiation so peers can indicate whether they
want/need the RTR and what type of RTR (0B read, 0B write, or 0B send)
should be sent. This will be done by standardizing a few bits of the
private data in order to negotiate all this. However this patch
enables peer-to-peer applications now and allows most of the required
firmware and driver changes to be done and tested now.
Design:
- Add a module option, peer2peer, to enable this mode.
- New firmware support for peer-to-peer mode:
- a new bit in the rdma_init WR to tell it to do peer-2-peer
and what form of RTR message to send or expect.
- process _all_ preposted recvs before moving the connection
into rdma mode.
- passive side: defer completing the rdma_init WR until all
pre-posted recvs are processed. Suspend SQ processing until
the RTR is received.
- active side: expect and process the 0B read WR on offload TX
queue. Defer completing the rdma_init WR until all
pre-posted recvs are processed. Suspend SQ processing until
the 0B read WR is processed from the offload TX queue.
- If peer2peer is set, driver posts 0B read request on offload TX
queue just after posting the rdma_init WR to the offload TX queue.
- Add CQ poll logic to ignore unsolicitied read responses.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
cxgb3 only supports 4GB memory regions. The lustre RDMA code uses
this attribute and currently has to code around our bad setting.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Open MPI and other stress testing exposed a few bad bugs in handling
aborts in the middle of a normal close. Fix these by:
- serializing abort reply and peer abort processing with disconnect
processing
- warning (and ignoring) if ep timer is stopped when it wasn't running
- cleaning up disconnect path to correctly deal with aborting and
dead endpoints
- in iwch_modify_qp(), taking a ref on the ep before releasing the qp
lock if iwch_ep_disconnect() will be called. The ref is dropped
after calling disconnect.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Extend the mlx4_cq_resize() API with a way to set the "collapsed" flag
for the CQ being created.
Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add a new parameter, dmasync, to the ib_umem_get() prototype. Use dmasync = 1
when mapping user-allocated CQs with ib_umem_get().
Signed-off-by: Arthur Kepner <akepner@sgi.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the volatile qualifier from the cq_vbase member of struct
nes_hw_cq, and add an rmb() in the one place where it looks like
access order might make a difference. As usual, removing a volatile
qualifier in a declaration is actually a bug fix, since a volatile
qualifier is not sufficient to make sure that aggressively
out-of-order CPUs don't reorder things and cause incorrect results.
For example, a CPU might speculatively execute reads of other cqe
fields before the NIC hardware has written those fields and before it
has set the NES_CQE_VALID bit (even though those reads come after the
test of the NES_CQE_VALID bit in program order), but then when the CPU
actually executes the conditional test of the NES_CQE_VALID, the bit
has been set, and the CPU will proceed with the results of the earlier
speculative execution and end up using bogus data.
This also gets rid of the warning:
drivers/infiniband/hw/nes/nes_verbs.c: In function 'nes_destroy_cq':
drivers/infiniband/hw/nes/nes_verbs.c:1978: warning: passing argument 3 of 'pci_free_consistent' discards qualifiers from pointer target type
Signed-off-by: Roland Dreier <rolandd@cisco.com>
