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>
* 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/roland/infiniband: (49 commits)
IB: Set class_dev->dev in core for nice device symlink
IB/ehca: Implement modify_port
IB/umad: Clarify documentation of transaction ID
IPoIB/cm: spin_lock_irqsave() -> spin_lock_irq() replacements
IB/mad: Change SMI to use enums rather than magic return codes
IB/umad: Implement GRH handling for sent/received MADs
IB/ipoib: Use ib_init_ah_from_path to initialize ah_attr
IB/sa: Set src_path_bits correctly in ib_init_ah_from_path()
IB/ucm: Simplify ib_ucm_event()
RDMA/ucma: Simplify ucma_get_event()
IB/mthca: Simplify CQ cleaning in mthca_free_qp()
IB/mthca: Fix mthca_write_mtt() on HCAs with hidden memory
IB/mthca: Update HCA firmware revisions
IB/ipath: Fix WC format drift between user and kernel space
IB/ipath: Check that a UD work request's address handle is valid
IB/ipath: Remove duplicate stuff from ipath_verbs.h
IB/ipath: Check reserved memory keys
IB/ipath: Fix unit selection when all CPU affinity bits set
IB/ipath: Don't allow QPs 0 and 1 to be opened multiple times
IB/ipath: Disable IB link earlier in shutdown sequence
...
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)
Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
One less thing for drivers writers to worry about.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All RDMA drivers except ehca set class_dev->dev to their dma_device
value (ehca leaves this unset). dma_device is the only value that
makes any sense, so move this assignment to core/sysfs.c. This reduce
the duplicated code in the rest of the drivers and gives ehca a nice
/sys/class/infiniband/ehcaX/device symlink.
Signed-off-by: Joachim Fenkes <fenkes@de.ibm.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>
SLAB_ATOMIC is an alias of GFP_ATOMIC
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It is possible to swap the CQs used for send_cq and recv_cq when
creating two different QPs. If these two QPs are then destroyed at
the same time, an AB-BA deadlock can occur because the CQ locks are
taken our of order. Fix this by always taking CQ locks in a fixed
order.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The amso1100 driver was missing a couple of __devinit/__devexit
annotations for init/cleanup functions that are called from
__devinit/__devexit functions.
Reported by Randy Dunlap <randy.dunlap@oracle.com>.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Fix the AMSO1100 firmware version computation, which was broken
due to "&&" being used where "&" should have.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Rework some load-time error handling: c2_register_device() leaked when
it failed, and the function that called it didn't check the return code.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The Ammasso driver needs to use dma_alloc_coherent() for
allocating memory that will be used by the HW for dma.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This patch fixes a NULL dereference spotted by the Coverity checker.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Acked-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
pci_module_init() convertion in amso1100 driver.
Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Since pr_debug() has changed from a macro to an inline function when
DEBUG is not defined, its arguments now need to be defined even when
debugging is off. Therefore to_event_str() and to_qp_state_str() need
to be moved out of #ifdef DEBUG. The compiler will throw the
definitions away if DEBUG is not defined, but it needs to be able to
see that the functions exist.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The AMSO driver was not thread-safe in the post WR code and had
code that would sleep if the WR post FIFO was full. Since these
functions can be called on interrupt level I changed the sleep to a
udelay.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
If the allocation of mr fails, then c2_reg_phys_mr() leaks the
page_list array it allocated earlier.
This was Coverity CID #1413.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Another NULL dereference spotted by the Coverity checker (cid #1395):
In case we can't alloc the vq_req, we goto bail1, where we call
vq_req_free(c2dev, vq_req); which then dereferences vq_req.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Acked-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Make sure all 64-bit quantities are cast to unsigned long long
when printed with "%ll" printk formats.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
indirect chains of includes are arch-specific and can't
be relied upon... (hell, even attempt to build it for
itanic would trigger vmalloc.h ones; err.h triggers
on e.g. alpha).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a driver for the Ammasso 1100 gigabit ethernet RNIC.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
