SVR5

physreq_prep(D3)

physreq_prep -- prepare a physical alignment requirements structure for use

Synopsis

   #include <sys/types.h>
   #include <sys/kmem.h>
   #include <sys/ddi.h>
   
   boolean_t physreq_prep(physreq_t *preqp, int flag);

Description

physreq_prep prepares a physreq structure for use. The physreq structure is used by routines to define alignment constraints on physical addresses.

Arguments

preqp: Pointer to a previously allocated physreq(D4) structure.
flag: Indicates whether the allocation may sleep or not, and is set to KM_SLEEP or KM_NOSLEEP.

Return values

On success, physreq_prep returns B_TRUE.

On failure, the routine returns B_FALSE, either due to allocation failure in the KM_NOSLEEP case or due to unsupportable constraints specified in preqp.

Usage

physreq_prep must be called after all necessary fields in the structure pointed to by preqp have been set, but before the structure is passed to any I/O or allocation routine such as buf_breakup(D3), kmem_alloc_physreq(D3), or msgphysreq(D3str).

This routine can be called multiple times on the same physreq structure.

If the driver modifies the fields of the preqp after it has been prepped, then the driver must call physreq_prep( ) again before actually using it.

Context and synchronization

If flag is set to KM_NOSLEEP, non-blockable, initialization, or interrupt context.

If flag is set to KM_SLEEP, user context.

Hardware applicability

All

Version applicability

ddi: 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp, 8, 8mp

Differences between versions

References

buf_breakup(D3), kmem_alloc_physreq(D3), kmem_zalloc_physreq(D3), msgphysreq(D3str), physreq_alloc(D3), physreq_free(D3), physreq(D4)

``Memory allocation'' in HDK Technical Reference