iovec(D4)

iovec -- data storage structure for I/O using the uio structure

Syntax

   #include <sys/types.h>
   #include <sys/uio.h>
   #include <sys/ddi.h>

Description

The iovec structure describes a data storage area for transfer with a uio(D4) structure. Conceptually, it may be thought of as a base address and length specification.

Usage

A separate interface does not currently exist for allocating iovec structures. The driver may use kmem_zalloc(D3) to allocate them, or allocate them statically.

Structure definitions

The iovec structure contains the following members:

   caddr_t	iov_base;
   int	iov_len;

The driver may only set iovec structure members to initialize them for a data transfer for which the driver created the iovec structure. The driver must not otherwise change iovec structure members, although drivers may read them. The iovec structure members available to the driver are:

iov_base: contains the address for a range of memory to or from which data are transferred.
iov_len: contains the number of bytes of data to be transferred to or from the range of memory starting at iov_base.

Applicable hardware

All

Version applicability

ddi: 1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp, 8, 8mp

References

physiock(D3), uiomove(D3), ureadc(D3), uwritec(D3), uio(D4)