dat_lmr_create(3DATDirect Access Transport Library Functiodat_lmr_create(3DAT)NAMEdat_lmr_create - register a memory region with an IA
SYNOPSIS
cc [ flag... ] file... -ldat [ library... ]
#include <dat/udat.h>
DAT_RETURN
dat_lmr_create (
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
)
PARAMETERS
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.
DAT_MEM_TYPE_VIRTUAL
Consumer virtual memory.
Region description: A pointer to a contiguous user virtual
range.
Length: Length of the Memory Region.
DAT_MEM_TYPE_SO_VIRTUAL
Consumer virtual memory with strong memory ordering. This type
is a Solaris specific addition. If the ia_handle was opened
without RO_AWARE_ (see dat_ia_open(3DAT)), then type
DAT_MEM_TYPE_VIRTUAL is implicitly converted to this type.
Region description: A pointer to a contiguous user virtual
range.
Length: Length of the Memory Region.
DAT_MEM_TYPE_LMR
LMR.
Region description: An LMR_handle.
Length: Length parameter is ignored.
DAT_MEM_TYPE_SHARED_VIRTUAL
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 Plat‐
form-specific primitives.
Region description: A structure with 2 elements, where the
first one is of type DAT_LMR_COOKIE and is a unique identifier
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_description
Pointer to type-specific data describing the memory in the region
to be registered. The type is derived from the mem_type parameter.
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:
Local Read DAT_MEM_PRIV_LOCAL_READ_FLAG
0x01 Local read access requested.
Local Write DAT_MEM_PRIV_LOCAL_WRITE_FLAG
0x10 Local write access requested.
Remote Read DAT_MEM_PRIV_REMOTE_READ_FLAG
0x02 Remote read access requested.
Remote Write DAT_MEM_PRIV_REMOTE_WRITE_FLAG
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_address
Actual base address of the memory registered by the Provider.
DESCRIPTION
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 buf‐
fers of DTOs and for binding RMRs, and lmr_handle can be used for cre‐
ating 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 Con‐
sumer 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 table
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 identi‐
fier 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 null-
terminated string.
The return value of rmr_context can be transferred by the local Con‐
sumer 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 privileges
are given for Memory Region unless explicitly asked for by the Con‐
sumer.
RETURN VALUES
DAT_SUCCESS The operation was successful.
DAT_UNSUFFICIENT_RESOURCES The operation failed due to resource lim‐
itations.
DAT_INVALID_PARAMETER Invalid parameter.
DAT_INVALID_HANDLE Invalid DAT handle.
DAT_INVALID_STATE Parameter in an invalid state. For exam‐
ple, shared virtual buffer was not cre‐
ated shared by the platform.
DAT_MODEL_NOT_SUPPORTED The requested Model was not supported by
the Provider. For example, requested Mem‐
ory Type was not supported by the
Provider.
USAGE
Consumers can create an LMR over the existing LMR memory with different
Protection Zones and privileges using previously created IA translation
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).
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Committed │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │Safe │
├─────────────────────────────┼─────────────────────────────┤
│Standard │uDAPL, 1.1, 1.2 (except │
│ │DAT_MEM_TYPE_SO_VIRTUAL) │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOdat_lmr_free(3DAT), libdat(3LIB), attributes(5)SunOS 5.11 28 Jan 2009 dat_lmr_create(3DAT)