svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.
ddi_dma_alloc_handle(9f)
ddi_dma_alloc_handle(9F) Kernel Functions ddi_dma_alloc_handle(9F)
NAME
ddi_dma_alloc_handle - allocate DMA handle
SYNOPSIS
#include <sys/ddi.h>
#include <sys/sunddi.h>
int ddi_dma_alloc_handle(dev_info_t *dip, ddi_dma_attr_t *attr,
int (*callback) (caddr_t), caddr_t arg, ddi_dma_handle_t *handlep);
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI).
PARAMETERS
dip Pointer to the device's dev_info structure.
attr Pointer to a DMA attribute structure for this device (see
ddi_dma_attr(9S)).
callback The address of a function to call back later if resources
aren't available now. The following special function
addresses may also be used.
DDI_DMA_SLEEP Wait until resources are available.
DDI_DMA_DONTWAIT Do not wait until resources are avail‐
able and do not schedule a callback.
arg Argument to be passed to a callback function, if such a
function is specified.
handlep Pointer to the DMA handle to be initialized.
DESCRIPTION
ddi_dma_alloc_handle() allocates a new DMA handle. A DMA handle is an
opaque object used as a reference to subsequently allocated DMA
resources. ddi_dma_alloc_handle() accepts as parameters the device
information referred to by dip and the device's DMA attributes
described by a ddi_dma_attr(9S) structure. A successful call to
ddi_dma_alloc_handle() fills in the value pointed to by handlep. A DMA
handle must only be used by the device for which it was allocated and
is only valid for one I/O transaction at a time.
The callback function, callback, indicates how a caller wants to handle
the possibility of resources not being available. If callback is set to
DDI_DMA_DONTWAIT, then the caller does not care if the allocation
fails, and can handle an allocation failure appropriately. If callback
is set to DDI_DMA_SLEEP, then the caller wishes to have the allocation
routines wait for resources to become available. If any other value is
set, and a DMA resource allocation fails, this value is assumed to be a
function to call at a later time when resources may become available.
When the specified function is called, it is passed arg as an argument.
The specified callback function must return either DDI_DMA_CALL‐
BACK_RUNOUT or DDI_DMA_CALLBACK_DONE. DDI_DMA_CALLBACK_RUNOUT indicates
that the callback routine attempted to allocate DMA resources but
failed to do so, in which case the callback function is put back on a
list to be called again later. DDI_DMA_CALLBACK_DONE indicates either
success at allocating DMA resources or the driver no longer wishes to
retry.
The callback function is called in interrupt context. Therefore, only
system functions that are accessible from interrupt context is avail‐
able. The callback function must take whatever steps necessary to pro‐
tect its critical resources, data structures, queues, and so forth.
When a DMA handle is no longer needed, ddi_dma_free_handle(9F) must be
called to free the handle.
RETURN VALUES
ddi_dma_alloc_handle() returns:
DDI_SUCCESS Successfully allocated a new DMA handle.
DDI_DMA_BADATTR The attributes specified in the ddi_dma_attr(9S)
structure make it impossible for the system to
allocate potential DMA resources.
DDI_DMA_NORESOURCES No resources are available.
CONTEXT
ddi_dma_alloc_handle() can be called from user, kernel, or interrupt
context, except when callback is set to DDI_DMA_SLEEP, in which case it
can be called from user or kernel context only.
SEE ALSO
ddi_dma_addr_bind_handle(9F), ddi_dma_buf_bind_handle(9F),
ddi_dma_burstsizes(9F), ddi_dma_free_handle(9F), ddi_dma_unbind_han‐
dle(9F), ddi_dma_attr(9S)
Writing Device Drivers in Oracle Solaris 11.4
Oracle Solaris 11.4 22 Sep 1996 ddi_dma_alloc_handle(9F)