linux/drivers/infiniband/Kconfig
Roland Dreier f7c6a7b5d5 IB/uverbs: Export ib_umem_get()/ib_umem_release() to modules
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>
2007-05-08 18:00:37 -07:00

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menu "InfiniBand support"
config INFINIBAND
depends on PCI || BROKEN
tristate "InfiniBand support"
---help---
Core support for InfiniBand (IB). Make sure to also select
any protocols you wish to use as well as drivers for your
InfiniBand hardware.
config INFINIBAND_USER_MAD
tristate "InfiniBand userspace MAD support"
depends on INFINIBAND
---help---
Userspace InfiniBand Management Datagram (MAD) support. This
is the kernel side of the userspace MAD support, which allows
userspace processes to send and receive MADs. You will also
need libibumad from <http://www.openib.org>.
config INFINIBAND_USER_ACCESS
tristate "InfiniBand userspace access (verbs and CM)"
depends on INFINIBAND
---help---
Userspace InfiniBand access support. This enables the
kernel side of userspace verbs and the userspace
communication manager (CM). This allows userspace processes
to set up connections and directly access InfiniBand
hardware for fast-path operations. You will also need
libibverbs, libibcm and a hardware driver library from
<http://www.openib.org>.
config INFINIBAND_USER_MEM
bool
depends on INFINIBAND_USER_ACCESS != n
default y
config INFINIBAND_ADDR_TRANS
bool
depends on INFINIBAND && INET
default y
source "drivers/infiniband/hw/mthca/Kconfig"
source "drivers/infiniband/hw/ipath/Kconfig"
source "drivers/infiniband/hw/ehca/Kconfig"
source "drivers/infiniband/hw/amso1100/Kconfig"
source "drivers/infiniband/hw/cxgb3/Kconfig"
source "drivers/infiniband/ulp/ipoib/Kconfig"
source "drivers/infiniband/ulp/srp/Kconfig"
source "drivers/infiniband/ulp/iser/Kconfig"
endmenu