path: root/drivers/infiniband/Kconfig
diff options
authorRoland Dreier <rolandd@cisco.com>2007-03-04 16:15:11 -0800
committerRoland Dreier <rolandd@cisco.com>2007-05-08 18:00:37 -0700
commitf7c6a7b5d59980b076abbf2ceeb8735591290285 (patch)
tree29c35b47052bba87f031a4744d8ad12ff5187149 /drivers/infiniband/Kconfig
parentMerge branch 'hwmon-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6 (diff)
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>
Diffstat (limited to 'drivers/infiniband/Kconfig')
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/infiniband/Kconfig b/drivers/infiniband/Kconfig
index 66b36de9fa6f..82afba5c0bf4 100644
--- a/drivers/infiniband/Kconfig
+++ b/drivers/infiniband/Kconfig
@@ -29,6 +29,11 @@ config INFINIBAND_USER_ACCESS
libibverbs, libibcm and a hardware driver library from
+ bool
+ depends on INFINIBAND_USER_ACCESS != n
+ default y
depends on INFINIBAND && INET