When memory pinned with ib_umem_get() is released, ib_umem_release()
needs to subtract the amount of memory being unpinned from
mm->locked_vm. However, ib_umem_release() may be called with
mm->mmap_sem already held for writing if the memory is being released
as part of an munmap() call, so it is sometimes necessary to defer
this accounting into a workqueue.
However, the work struct used to defer this accounting is dynamically
allocated before it is queued, so there is the possibility of failing
that allocation. If the allocation fails, then ib_umem_release has no
choice except to bail out and leave the process with a permanently
elevated locked_vm.
Fix this by allocating the structure to defer accounting as part of
the original struct ib_umem, so there's no possibility of failing a
later allocation if creating the struct ib_umem and pinning memory
succeeds.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Export ib_umem_get()/ib_umem_release() and put low-level drivers in
control of when to call ib_umem_get() to pin and DMA map userspace,
rather than always calling it in ib_uverbs_reg_mr() before calling the
low-level driver's reg_user_mr method.
Also move these functions to be in the ib_core module instead of
ib_uverbs, so that driver modules using them do not depend on
ib_uverbs.
This has a number of advantages:
- It is better design from the standpoint of making generic code a
library that can be used or overridden by device-specific code as
the details of specific devices dictate.
- Drivers that do not need to pin userspace memory regions do not
need to take the performance hit of calling ib_mem_get(). For
example, although I have not tried to implement it in this patch,
the ipath driver should be able to avoid pinning memory and just
use copy_{to,from}_user() to access userspace memory regions.
- Buffers that need special mapping treatment can be identified by
the low-level driver. For example, it may be possible to solve
some Altix-specific memory ordering issues with mthca CQs in
userspace by mapping CQ buffers with extra flags.
- Drivers that need to pin and DMA map userspace memory for things
other than memory regions can use ib_umem_get() directly, instead
of hacks using extra parameters to their reg_phys_mr method. For
example, the mlx4 driver that is pending being merged needs to pin
and DMA map QP and CQ buffers, but it does not need to create a
memory key for these buffers. So the cleanest solution is for mlx4
to call ib_umem_get() in the create_qp and create_cq methods.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
* 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/roland/infiniband:
IPoIB: Convert to NAPI
IB: Return "maybe missed event" hint from ib_req_notify_cq()
IB: Add CQ comp_vector support
IB/ipath: Fix a race condition when generating ACKs
IB/ipath: Fix two more spin lock problems
IB/fmr_pool: Add prefix to all printks
IB/srp: Set proc_name
IB/srp: Add orig_dgid sysfs attribute to scsi_host
IPoIB/cm: Don't crash if remote side uses one QP for both directions
RDMA/cxgb3: Support for new abort logic
RDMA/cxgb3: Initialize cpu_idx field in cpl_close_listserv_req message
RDMA/cxgb3: Fail qp creation if the requested max_inline is too large
RDMA/cxgb3: Fix TERM codes
IPoIB/cm: Fix error handling in ipoib_cm_dev_open()
IB/ipath: Don't corrupt pending mmap list when unmapped objects are freed
IB/mthca: Work around kernel QP starvation
IB/ipath: Don't put QP in timeout queue if waiting to send
IB/ipath: Don't call spin_lock_irq() from interrupt context
The semantics defined by the InfiniBand specification say that
completion events are only generated when a completions is added to a
completion queue (CQ) after completion notification is requested. In
other words, this means that the following race is possible:
while (CQ is not empty)
ib_poll_cq(CQ);
// new completion is added after while loop is exited
ib_req_notify_cq(CQ);
// no event is generated for the existing completion
To close this race, the IB spec recommends doing another poll of the
CQ after requesting notification.
However, it is not always possible to arrange code this way (for
example, we have found that NAPI for IPoIB cannot poll after
requesting notification). Also, some hardware (eg Mellanox HCAs)
actually will generate an event for completions added before the call
to ib_req_notify_cq() -- which is allowed by the spec, since there's
no way for any upper-layer consumer to know exactly when a completion
was really added -- so the extra poll of the CQ is just a waste.
Motivated by this, we add a new flag "IB_CQ_REPORT_MISSED_EVENTS" for
ib_req_notify_cq() so that it can return a hint about whether the a
completion may have been added before the request for notification.
The return value of ib_req_notify_cq() is extended so:
< 0 means an error occurred while requesting notification
== 0 means notification was requested successfully, and if
IB_CQ_REPORT_MISSED_EVENTS was passed in, then no
events were missed and it is safe to wait for another
event.
> 0 is only returned if IB_CQ_REPORT_MISSED_EVENTS was
passed in. It means that the consumer must poll the
CQ again to make sure it is empty to avoid the race
described above.
We add a flag to enable this behavior rather than turning it on
unconditionally, because checking for missed events may incur
significant overhead for some low-level drivers, and consumers that
don't care about the results of this test shouldn't be forced to pay
for the test.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add a num_comp_vectors member to struct ib_device and extend
ib_create_cq() to pass in a comp_vector parameter -- this parallels
the userspace libibverbs API. Update all hardware drivers to set
num_comp_vectors to 1 and have all ULPs pass 0 for the comp_vector
value. Pass the value of num_comp_vectors to userspace rather than
hard-coding a value of 1.
We want multiple CQ event vector support (via MSI-X or similar for
adapters that can generate multiple interrupts), but it's not clear
how many vectors we want, or how we want to deal with policy issues
such as how to decide which vector to use or how to set up interrupt
affinity. This patch is useful for experimenting, since no core
changes will be necessary when updating a driver to support multiple
vectors, and we know that we want to make at least these changes
anyway.
Signed-off-by: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
I noticed that many source files include <linux/pci.h> while they do
not appear to need it. Here is an attempt to clean it all up.
In order to find all possibly affected files, I searched for all
files including <linux/pci.h> but without any other occurence of "pci"
or "PCI". I removed the include statement from all of these, then I
compiled an allmodconfig kernel on both i386 and x86_64 and fixed the
false positives manually.
My tests covered 66% of the affected files, so there could be false
positives remaining. Untested files are:
arch/alpha/kernel/err_common.c
arch/alpha/kernel/err_ev6.c
arch/alpha/kernel/err_ev7.c
arch/ia64/sn/kernel/huberror.c
arch/ia64/sn/kernel/xpnet.c
arch/m68knommu/kernel/dma.c
arch/mips/lib/iomap.c
arch/powerpc/platforms/pseries/ras.c
arch/ppc/8260_io/enet.c
arch/ppc/8260_io/fcc_enet.c
arch/ppc/8xx_io/enet.c
arch/ppc/syslib/ppc4xx_sgdma.c
arch/sh64/mach-cayman/iomap.c
arch/xtensa/kernel/xtensa_ksyms.c
arch/xtensa/platform-iss/setup.c
drivers/i2c/busses/i2c-at91.c
drivers/i2c/busses/i2c-mpc.c
drivers/media/video/saa711x.c
drivers/misc/hdpuftrs/hdpu_cpustate.c
drivers/misc/hdpuftrs/hdpu_nexus.c
drivers/net/au1000_eth.c
drivers/net/fec_8xx/fec_main.c
drivers/net/fec_8xx/fec_mii.c
drivers/net/fs_enet/fs_enet-main.c
drivers/net/fs_enet/mac-fcc.c
drivers/net/fs_enet/mac-fec.c
drivers/net/fs_enet/mac-scc.c
drivers/net/fs_enet/mii-bitbang.c
drivers/net/fs_enet/mii-fec.c
drivers/net/ibm_emac/ibm_emac_core.c
drivers/net/lasi_82596.c
drivers/parisc/hppb.c
drivers/sbus/sbus.c
drivers/video/g364fb.c
drivers/video/platinumfb.c
drivers/video/stifb.c
drivers/video/valkyriefb.c
include/asm-arm/arch-ixp4xx/dma.h
sound/oss/au1550_ac97.c
I would welcome test reports for these files. I am fine with removing
the untested files from the patch if the general opinion is that these
changes aren't safe. The tested part would still be nice to have.
Note that this patch depends on another header fixup patch I submitted
to LKML yesterday:
[PATCH] scatterlist.h needs types.h
http://lkml.org/lkml/2007/3/01/141
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Extend rdma_cm to support multicast communication. Multicast support
is added to the existing RDMA_PS_UDP port space, as well as a new
RDMA_PS_IPOIB port space. The latter port space allows joining the
multicast groups used by IPoIB, which enables offloading IPoIB traffic
to a separate QP. The port space determines the signature used in the
MGID when joining the group. The newly added RDMA_PS_IPOIB also
allows for unicast operations, similar to RDMA_PS_UDP.
Supporting the RDMA_PS_IPOIB requires changing how UD QPs are initialized,
since we can no longer assume that the qkey is constant. This requires
saving the Q_Key to use when attaching to a device, so that it is
available when creating the QP. The Q_Key information is exported to
the user through the existing rdma_init_qp_attr() interface.
Multicast support is also exported to userspace through the rdma_ucm.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The IB SA tracks multicast join/leave requests on a per port basis and
does not do any reference counting: if two users of the same port join
the same group, and one leaves that group, then the SA will remove the
port from the group even though there is one user who wants to stay a
member left. Therefore, in order to support multiple users of the
same multicast group from the same port, we need to perform reference
counting locally.
To do this, add an multicast submodule to ib_sa to perform reference
counting of multicast join/leave operations. Modify ib_ipoib (the
only in-kernel user of multicast) to use the new interface.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Make the untyped data region in ib_user_mad have type u64 so that it
gets aligned properly. This avoids alignment faults in ib_umad when
casting the data field to an rmpp_mad and accessing the 64-bit tid
field on architectures like ia64.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
struct ib_wc currently only includes the local QP number: this matches
the IB spec, but seems mostly useless. The following patch replaces
this with the pointer to qp itself, and updates all low level drivers
and all users.
This has the following advantages:
- Ability to get a per-qp context through wc->qp->qp_context
- Existing drivers already have the qp pointer ready in poll cq, so
this change actually saves a tiny bit (extra memory read) on data path
(for ehca it would actually be expensive to find the QP pointer when
polling a CQ, but ehca does not support SRQ so we can leave wc->qp as
NULL for ehca)
- Users that need the QP number can still get it through wc->qp->qp_num
Use case:
In IPoIB connected mode code, I have a common CQ shared by multiple
QPs. To track connection usage, I need a way to get at some per-QP
context upon the completion, and I would like to avoid allocating
context object per work request just to stick a QP pointer into it.
With this code, I can just use wc->qp->qp_context.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
<rdma/ib_verbs.h> uses struct kref, so it should include <linux/kref.h>
explicitly to avoid hidden include dependencies.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The ib_dma_alloc_coherent() wrapper uses a u64* for the dma_handle
parameter, unlike dma_alloc_coherent, which uses dma_addr_t*. This
means that we need a temporary variable to handle the case when
ib_dma_alloc_coherent() just falls through directly to
dma_alloc_coherent() on architectures where sizeof u64 != sizeof
dma_addr_t.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
At least on PPC, the "op ? op : dma" construct causes a compile failure
because the dma_* is a do{}while(0) macro.
This turns all of them into proper if/else to avoid this problem.
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The QLogic InfiniPath HCAs use programmed I/O instead of HW DMA.
This patch allows a verbs device driver to interpose on DMA mapping
function calls in order to avoid relying on bus_to_virt() and
phys_to_virt() to undo the mappings created by dma_map_single(),
dma_map_sg(), etc.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Export the rdma cm interfaces to userspace via a misc device.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Allow the use of UD QPs through the rdma_cm, in order to provide
address translation services for resolving IB addresses for datagram
messages using SIDR.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
During connection establishment, the passive side of a connection can
receive messages from the active side before the connection event has
been delivered to the user. Allow the passive side to send messages
in response to received data before the event is delivered. To handle
the case where the connection messages are lost, a new rdma_notify()
function is added that users may invoke to force a connection into the
established state.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Connection information was never given to the recipient of a
connection request or reply message. Only the event was delivered.
Report the connection data with the event to allows user to
reject the connection based on the requested parameters, or adjust
their resources to match the request.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The qp_type parameter into the rdma_cm is unneeded, and can be
misleading. The QP type should be determined from the port space.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The ib_cm_establish() function is replaced with a more generic
ib_cm_notify(). This routine is used to notify the CM that failover
has occurred, so that future CM messages (LAP, DREQ) reach the remote
CM. (Currently, we continue to use the original path) This bumps the
userspace CM ABI.
New alternate path information is captured when a LAP message is sent
or received. This allows QP attributes to be initialized for the user
when a new path is loaded after failover occurs.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Require registration with ib_addr module to prevent caller from
unloading while a callback is in progress.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Return the sq_draining value back to user space for query_qp instead
of the en_sqd_async notify value, which is valid only for
modify_qp. For query_qp, the draining status should returned.
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Relevant SA queries are actually "greater than" / "less than", not
"greater than or equal" / "less than or equal" as the names imply.
(See IB spec 1.2 Vol 1, 15.2.5.16 PATHRECORD/Table 205 PathRecord)
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Document the reject sending and modifying QP to error done in rdma_accept().
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Clarify that rdma_destroy_id cancels outstanding asynchronous operations on the
Associated id.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Require users to register with SA module, to prevent the sa_query
module text from going away while an SA query callback is still
running. Update all in-tree users for the new interface.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Modifications to the existing rdma header files, core files, drivers,
and ulp files to support iWARP, including:
- Hook iWARP CM into the build system and use it in rdma_cm.
- Convert enum ib_node_type to enum rdma_node_type, which includes
the possibility of RDMA_NODE_RNIC, and update everything for this.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add an iWARP Connection Manager (CM), which abstracts connection
management for iWARP devices (RNICs). It is a logical instance of the
xx_cm where xx is the transport type (ib or iw). The symbols exported
are used by the transport independent rdma_cm module, and are
available also for transport dependent ULPs.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Pass a struct ib_udata to the low-level driver's ->modify_srq() and
->modify_qp() methods, so that it can get to the device-specific data
passed in by the userspace driver.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add a ib_uverbs_resize_cq_resp.driver_data field so that low-level
drivers can return data from a resize CQ operation to userspace. Have
ib_uverbs_resize_cq() only copy the cqe field, to avoid having to bump
the userspace ABI.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Validate MADs sent by userspace clients for spec compliance with
C13-18.1.1 (prevent duplicate requests and responses sent on the
same port). Without this, RMPP transactions get aborted because
of duplicate packets.
This patch is similar to that provided by Jack Morgenstein.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
ib_fmr_pool_map_phys gets the virtual address by pointer but never writes
there, and users (e.g. srp) seem to assume this and ignore the value
returned. This patch cleans up the API to get the VA by value, and updates
all users.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Acked-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The device address contains unsigned character arrays, which contain raw GID
addresses. The GIDs may not be naturally aligned, so do not cast them to
structures or unions.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds the Kbuild files listing the files which are to be installed by
the 'headers_install' make target, in generic directories.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Currently, all userspace verbs operations that call into the kernel
are serialized by ib_uverbs_idr_mutex. This can be a scalability
issue for some workloads, especially for devices driven by the ipath
driver, which needs to call into the kernel even for datapath
operations.
Fix this by adding reference counts to the userspace objects, and then
converting ib_uverbs_idr_mutex into a spinlock that only protects the
idrs long enough to take a reference on the object being looked up.
Because remove operations may fail, we have to do a slightly funky
two-step deletion, which is described in the comments at the top of
uverbs_cmd.c.
This also still leaves ib_uverbs_idr_lock as a single lock that is
possibly subject to contention. However, the lock hold time will only
be a single idr operation, so multiple threads should still be able to
make progress, even if ib_uverbs_idr_lock is being ping-ponged.
Surprisingly, these changes even shrink the object code:
add/remove: 23/5 grow/shrink: 4/21 up/down: 633/-693 (-60)
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add a call to initialize address handle attributes given a path record.
This is used by the CM, and would be useful for users of UD QPs.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add a function to initialize address handle attributes from a work
completion. This functionality is duplicated by both verbs and the CM.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The P_Key is provided into a SIDR REQ in two places, once as a
parameter, and again in the path record. Remove the P_Key as a
parameter and always use the one given in the path record.
This change has no practical effect on ABI functionality.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Move ipath's struct port_info into <rdma/ib_smi.h>, so that it can be
used by mthca to implement client reregister support.
Remove the __attribute__((packed)) because all the members of the struct
are naturally aligned anyway.
Signed-off-by: Leonid Arsh <leonida@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add IB_EVENT_CLIENT_REREGISTER to enum so low-level drivers can
generate "client reregister" events.
Signed-off-by: Leonid Arsh <leonida@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add an LMC cache to struct ib_device, and add a function
ib_get_cached_lmc() to query the cache.
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Kernel connection management agent over InfiniBand that connects based
on IP addresses. The agent defines a generic RDMA connection
abstraction to support clients wanting to connect over different RDMA
devices.
The agent also handles RDMA device hotplug events on behalf of clients.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add an address translation service that maps IP addresses to
InfiniBand GID addresses using IPoIB.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Extend matching connection requests to listens in the InfiniBand CM to
include private data checks.
This allows applications to listen on the same service identifier,
with private data directing the request to the appropriate application.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Provide common handling for marshalling data between userspace clients
and kernel InfiniBand drivers.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Push translation of static rate to HCA format into low-level drivers,
where it belongs. For static rate encoding, use encoding of rate
field from IB standard PathRecord, with addition of value 0, for
backwards compatibility with current usage. The changes are:
- Add enum ib_rate to midlayer includes.
- Get rid of static rate translation in IPoIB; just use static rate
directly from Path and MulticastGroup records.
- Update mthca driver to translate absolute static rate into the
format used by hardware. This also fixes mthca's static rate
handling for HCAs that are capable of 4X DDR.
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add RMPP support for additional management classes that support it.
Also, validate RMPP is consistent with management class specified.
Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add support for sending and receiving large RMPP transfers. The old
code supports transfers only as large as a single contiguous kernel
memory allocation. This patch uses linked list of memory buffers when
sending and receiving data to avoid needing contiguous pages for
larger transfers.
Receive side: copy the arriving MADs in chunks instead of coalescing
to one large buffer in kernel space.
Send side: split a multipacket MAD buffer to a list of segments,
(multipacket_list) and send these using a gather list of size 2.
Also, save pointer to last sent segment, and retrieve requested
segments by walking list starting at last sent segment. Finally,
save pointer to last-acked segment. When retrying, retrieve
segments for resending relative to this pointer. When updating last
ack, start at this pointer.
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Roland Dreier