On 2020-11-05 14:41, Jason Gunthorpe wrote:
On Thu, Nov 05, 2020 at 08:42:00AM +0100, Christoph Hellwig wrote:
dma_virt_ops requires that all pages have a kernel virtual address.
Introduce a INFINIBAND_VIRT_DMA Kconfig symbol that depends on !HIGHMEM
and a large enough dma_addr_t, and make all three driver depend on the
new symbol.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
drivers/infiniband/Kconfig | 6 ++++++
drivers/infiniband/sw/rdmavt/Kconfig | 3 ++-
drivers/infiniband/sw/rxe/Kconfig | 2 +-
drivers/infiniband/sw/siw/Kconfig | 1 +
4 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/infiniband/Kconfig b/drivers/infiniband/Kconfig
index 32a51432ec4f73..81acaf5fb5be67 100644
+++ b/drivers/infiniband/Kconfig
@@ -73,6 +73,12 @@ config INFINIBAND_ADDR_TRANS_CONFIGFS
This allows the user to config the default GID type that the CM
uses for each device, when initiaing new connections.
+config INFINIBAND_VIRT_DMA
+ bool
+ default y
Oh, I haven't seen this kconfig trick with default before..
It's commonly done using the "def_bool" shorthand. I fact, I think
simply "def_bool !HIGHMEM" would suffice for the fundamental definition
here.
+ depends on !HIGHMEM
+ depends on !64BIT || ARCH_DMA_ADDR_T_64BIT
+
if INFINIBAND_USER_ACCESS || !INFINIBAND_USER_ACCESS
source "drivers/infiniband/hw/mthca/Kconfig"
source "drivers/infiniband/hw/qib/Kconfig"
diff --git a/drivers/infiniband/sw/rdmavt/Kconfig b/drivers/infiniband/sw/rdmavt/Kconfig
index 9ef5f5ce1ff6b0..c8e268082952b0 100644
+++ b/drivers/infiniband/sw/rdmavt/Kconfig
@@ -1,7 +1,8 @@
# SPDX-License-Identifier: GPL-2.0-only
config INFINIBAND_RDMAVT
tristate "RDMA verbs transport library"
- depends on X86_64 && ARCH_DMA_ADDR_T_64BIT
+ depends on INFINIBAND_VIRT_DMA
Usually I would expect a non-menu item to be used with select not
'depends on' - is the use of default avoiding that?
A select wouldn't make any sense here - if the user chooses to enable
the subsystem it can't automatically pull in "the absence of highmem"
from the arch code; there's still a literal dependency on certain
conditions being met for the option to be available. The intermediate
config symbol just abstracts that set of conditions.
Robin.
