dat_lmr_create(3DAT) Direct Access Transport Library Functions dat_lmr_create(3DAT)
dat_lmr_create - register a memory region with an IA
cc [ flag... ] file... -ldat [ library... ]
IN DAT_IA_HANDLE ia_handle,
IN DAT_MEM_TYPE mem_type,
IN DAT_REGION_DESCRIPTION region_description,
IN DAT_VLEN length,
IN DAT_PZ_HANDLE pz_handle,
IN DAT_MEM_PRIV_FLAGS mem_privileges,
OUT DAT_LMR_HANDLE *lmr_handle,
OUT DAT_LMR_CONTEXT *lmr_context,
OUT DAT_RMR_CONTEXT *rmr_context,
OUT DAT_VLEN *registered_size,
OUT DAT_VADDR *registered_address
ia_handle Handle for an open instance of the IA.
mem_type Type of memory to be registered. The following list outlines the memory type specifications.
Consumer virtual memory.
Region description: A pointer to a contiguous user virtual range.
Length: Length of the Memory Region.
Region description: An LMR_handle.
Length: Length parameter is ignored.
Shared memory region. All DAT Consumers of the same uDAPL Provider specify the same Consumer cookie to indicate who is
sharing the shared memory region. This supports a peer-to-peer model of shared memory. All DAT Consumers of the shared
memory must allocate the memory region as shared memory using Platform-specific primitives.
Region description: A structure with 2 elements, where the first one is of type DAT_LMR_COOKIE and is a unique identi-
fier of the shared memory region, and the second one is a pointer to a contiguous user virtual range.
Length: Length of the Memory Region
region_descriptiPointer to type-specific data describing the memory in the region to be registered. The type is derived from the mem_type
length Length parameter accompanying the region_description.
pz_handle Handle for an instance of the Protection Zone.
mem_privileges: Consumer-requested memory access privileges for the registered local memory region. The Default value is
DAT_MEM_PRIV_NONE_FLAG. The constant value DAT_MEM_PRIV_ALL_FLAG = 0x33, which specifies both Read and Write privileges, is
also defined. Memory privilege definitions are as follows:
0x01 Local read access requested.
0x10 Local write access requested.
0x02 Remote read access requested.
0x20 Remote write access requested.
lmr_handle Handle for the created instance of the LMR.
lmr_context Context for the created instance of the LMR to use for DTO local buffers.
registered_size Actual memory size registered by the Provider.
registered_addreActual base address of the memory registered by the Provider.
The dat_lmr_create() function registers a memory region with an IA. The specified buffer must have been previously allocated and pinned by
the uDAPL Consumer on the platform. The Provider must do memory pinning if needed, which includes whatever OS-dependent steps are required
to ensure that the memory is available on demand for the Interface Adapter. uDAPL does not require that the memory never be swapped out;
just that neither the hardware nor the Consumer ever has to deal with it not being there. The created lmr_context can be used for local
buffers of DTOs and for binding RMRs, and lmr_handle can be used for creating other LMRs. For uDAPL the scope of the lmr_context is the
address space of the DAT Consumer.
The return values of registered_size and registered_address indicate to the Consumer how much the contiguous region of Consumer virtual
memory was registered by the Provider and where the region starts in the Consumer virtual address.
The mem_type parameter indicates to the Provider the kind of memory to be registered, and can take on any of the values defined in the ta-
ble in the PARAMETERS section.
The pz_handle parameter allows Consumers to restrict local accesses to the registered LMR by DTOs.
DAT_LMR_COOKIE is a pointer to a unique identifier of the shared memory region of the DAT_MEM_TYPE_SHARED_VIRTUAL DAT memory type. The
identifier is an array of 40 bytes allocated by the Consumer. The Provider must check the entire 40 bytes and shall not interpret it as a
The return value of rmr_context can be transferred by the local Consumer to a Consumer on a remote host to be used for an RDMA DTO.
If mem_privileges does not specify remote Read and Write privileges, rmr_context is not generated and NULL is returned. No remote privi-
leges are given for Memory Region unless explicitly asked for by the Consumer.
DAT_SUCCESS The operation was successful.
DAT_UNSUFFICIENT_RESOURCES The operation failed due to resource limitations.
DAT_INVALID_PARAMETER Invalid parameter.
DAT_INVALID_HANDLE Invalid DAT handle.
DAT_INVALID_STATE Parameter in an invalid state. For example, shared virtual buffer was not created shared by the platform.
DAT_MODEL_NOT_SUPPORTED The requested Model was not supported by the Provider. For example, requested Memory Type was not supported
by the Provider.
Consumers can create an LMR over the existing LMR memory with different Protection Zones and privileges using previously created IA trans-
lation table entries.
The Consumer should use rmr_context with caution. Once advertised to a remote peer, the rmr_context of the LMR cannot be invalidated. The
only way to invalidate it is to destroy the LMR with dat_lmr_free(3DAT).
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|Interface Stability |Standard: uDAPL, 1.1, 1.2 |
|MT-Level |Safe |
dat_lmr_free(3DAT), libdat(3LIB), attributes(5)
SunOS 5.10 16 Jul 2004 dat_lmr_create(3DAT)