IB/core: Add "type 2" memory windows support
This patch enhances the IB core support for Memory Windows (MWs).
MWs allow an application to have better/flexible control over remote
access to memory.
Two types of MWs are supported, with the second type having two flavors:
Type 1 - associated with PD only
Type 2A - associated with QPN only
Type 2B - associated with PD and QPN
Applications can allocate a MW once, and then repeatedly bind the MW
to different ranges in MRs that are associated to the same PD. Type 1
windows are bound through a verb, while type 2 windows are bound by
posting a work request.
The 32-bit memory key is composed of a 24-bit index and an 8-bit
key. The key is changed with each bind, thus allowing more control
over the peer's use of the memory key.
The changes introduced are the following:
* add memory window type enum and a corresponding parameter to ib_alloc_mw.
* type 2 memory window bind work request support.
* create a struct that contains the common part of the bind verb struct
ibv_mw_bind and the bind work request into a single struct.
* add the ib_inc_rkey helper function to advance the tag part of an rkey.
Consumer interface details:
* new device capability flags IB_DEVICE_MEM_WINDOW_TYPE_2A and
IB_DEVICE_MEM_WINDOW_TYPE_2B are added to indicate device support
for these features.
Devices can set either IB_DEVICE_MEM_WINDOW_TYPE_2A or
IB_DEVICE_MEM_WINDOW_TYPE_2B if it supports type 2A or type 2B
memory windows. It can set neither to indicate it doesn't support
type 2 windows at all.
* modify existing provides and consumers code to the new param of
ib_alloc_mw and the ib_mw_bind_info structure
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Shani Michaeli <shanim@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/cxgb4/mem.c b/drivers/infiniband/hw/cxgb4/mem.c
index afd8179..903a92d 100644
--- a/drivers/infiniband/hw/cxgb4/mem.c
+++ b/drivers/infiniband/hw/cxgb4/mem.c
@@ -650,7 +650,7 @@
return ERR_PTR(err);
}
-struct ib_mw *c4iw_alloc_mw(struct ib_pd *pd)
+struct ib_mw *c4iw_alloc_mw(struct ib_pd *pd, enum ib_mw_type type)
{
struct c4iw_dev *rhp;
struct c4iw_pd *php;
@@ -659,6 +659,9 @@
u32 stag = 0;
int ret;
+ if (type != IB_MW_TYPE_1)
+ return ERR_PTR(-EINVAL);
+
php = to_c4iw_pd(pd);
rhp = php->rhp;
mhp = kzalloc(sizeof(*mhp), GFP_KERNEL);