[RFC PATCH v2 2/9] RDMA: Allow registering MR with flush access flags

[Li Zhijian]

Users can use ibv_reg_mr(3) to register flush access flags.
NOTE that, we allow to register the access flags that are supported
by the HCA in both.

Device/HCA should enable IB_DEVICE_PLT_GLOBAL_VISIBILITY or
IB_DEVICE_PLT_PERSISTENT or both capabilities if it want to support
RDMA FLUSH.

Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxxxxx>
---
V2: combine [03/10] RDMA/rxe: Allow registering FLUSH flags for supported device only to this patch # Jason
    split RDMA_FLUSH to 2 capabilities
    Fix typo
---
 include/rdma/ib_verbs.h                 | 18 ++++++++++++++++--
 include/uapi/rdma/ib_user_ioctl_verbs.h |  2 ++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 4fa07b123c8d..7f5905180636 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -291,6 +291,9 @@ enum ib_device_cap_flags {
 	/* The device supports padding incoming writes to cacheline. */
 	IB_DEVICE_PCI_WRITE_END_PADDING		= (1ULL << 36),
 	IB_DEVICE_ALLOW_USER_UNREG		= (1ULL << 37),
+	/* Placement type attributes */
+	IB_DEVICE_PLT_GLOBAL_VISIBILITY		= (1ULL << 38),
+	IB_DEVICE_PLT_PERSISTENT		= (1ULL << 39),
 };
 
 enum ib_atomic_cap {
@@ -1444,10 +1447,14 @@ enum ib_access_flags {
 	IB_ACCESS_ON_DEMAND = IB_UVERBS_ACCESS_ON_DEMAND,
 	IB_ACCESS_HUGETLB = IB_UVERBS_ACCESS_HUGETLB,
 	IB_ACCESS_RELAXED_ORDERING = IB_UVERBS_ACCESS_RELAXED_ORDERING,
+	IB_ACCESS_FLUSH_GLOBAL_VISIBILITY = IB_UVERBS_ACCESS_FLUSH_GLOBAL_VISIBILITY,
+	IB_ACCESS_FLUSH_PERSISTENT = IB_UVERBS_ACCESS_FLUSH_PERSISTENT,
 
+	IB_ACCESS_FLUSHABLE = IB_ACCESS_FLUSH_GLOBAL_VISIBILITY |
+			      IB_ACCESS_FLUSH_PERSISTENT,
 	IB_ACCESS_OPTIONAL = IB_UVERBS_ACCESS_OPTIONAL_RANGE,
 	IB_ACCESS_SUPPORTED =
-		((IB_ACCESS_HUGETLB << 1) - 1) | IB_ACCESS_OPTIONAL,
+		((IB_ACCESS_FLUSH_PERSISTENT << 1) - 1) | IB_ACCESS_OPTIONAL,
 };
 
 /*
@@ -4301,6 +4308,7 @@ int ib_dealloc_xrcd_user(struct ib_xrcd *xrcd, struct ib_udata *udata);
 static inline int ib_check_mr_access(struct ib_device *ib_dev,
 				     unsigned int flags)
 {
+	u64 device_cap = ib_dev->attrs.device_cap_flags;
 	/*
 	 * Local write permission is required if remote write or
 	 * remote atomic permission is also requested.
@@ -4313,7 +4321,13 @@ static inline int ib_check_mr_access(struct ib_device *ib_dev,
 		return -EINVAL;
 
 	if (flags & IB_ACCESS_ON_DEMAND &&
-	    !(ib_dev->attrs.device_cap_flags & IB_DEVICE_ON_DEMAND_PAGING))
+	    !(device_cap & IB_DEVICE_ON_DEMAND_PAGING))
+		return -EINVAL;
+
+	if ((flags & IB_ACCESS_FLUSH_GLOBAL_VISIBILITY &&
+	    !(device_cap & IB_DEVICE_PLT_GLOBAL_VISIBILITY)) ||
+	    (flags & IB_ACCESS_FLUSH_PERSISTENT &&
+	    !(device_cap & IB_DEVICE_PLT_PERSISTENT)))
 		return -EINVAL;
 	return 0;
 }
diff --git a/include/uapi/rdma/ib_user_ioctl_verbs.h b/include/uapi/rdma/ib_user_ioctl_verbs.h
index 3072e5d6b692..2c28f90ec54c 100644
--- a/include/uapi/rdma/ib_user_ioctl_verbs.h
+++ b/include/uapi/rdma/ib_user_ioctl_verbs.h
@@ -57,6 +57,8 @@ enum ib_uverbs_access_flags {
 	IB_UVERBS_ACCESS_ZERO_BASED = 1 << 5,
 	IB_UVERBS_ACCESS_ON_DEMAND = 1 << 6,
 	IB_UVERBS_ACCESS_HUGETLB = 1 << 7,
+	IB_UVERBS_ACCESS_FLUSH_GLOBAL_VISIBILITY = 1 << 8,
+	IB_UVERBS_ACCESS_FLUSH_PERSISTENT = 1 << 9,
 
 	IB_UVERBS_ACCESS_RELAXED_ORDERING = IB_UVERBS_ACCESS_OPTIONAL_FIRST,
 	IB_UVERBS_ACCESS_OPTIONAL_RANGE =
-- 
2.31.1