Kernel Functions for Drivers ddi_dma_addr_bind_handle(9F)
NAME
ddi_dma_addr_bind_handle - binds an address to a DMA handle
SYNOPSIS
#include
#include
int ddi_dma_addr_bind_handle(ddi_dma_handle_t handle, struct as *as,
caddr_t addr, size_t len, uint_t flags, int (*callback) (caddr_t) ,
caddr_t arg, ddi_dma_cookie_t *cookiep, uint_t *ccountp);
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI).PARAMETERS
handle The DMA handle previously allocated by a callto ddi_dma_alloc_handle(9F).
as A pointer to an address space structure. This parameter should be set to NULL, which implies kernel address space. addr Virtual address of the memory object. len Length of the memory object in bytes. flags Valid flags include:DDI_DMA_WRITE Transfer direction is
from memory to I/O.
DDI_DMA_READ Transfer direction is
from I/O to memory.
DDI_DMA_RDWR Both read and write.
DDI_DMA_REDZONE Establish an MMU redzone
at end of the object.DDI_DMA_PARTIAL Partial resource alloca-
tion.SunOS 5.11 Last change: 26 Jul 1996 1
Kernel Functions for Drivers ddi_dma_addr_bind_handle(9F)
DDI_DMA_CONSISTENT Nonsequential, random,
and small block transfers.DDI_DMA_STREAMING Sequential, unidirec-
tional, block-sized, and
block-aligned transfers.
callback The address of a function to call back later ifresources are not currently available. The fol-
lowing special function addresses may also be used.DDI_DMA_SLEEP Wait until resources are
available.DDI_DMA_DONTWAIT Do not wait until
resources are available and do not schedule a callback. arg Argument to be passed to the callback function, callback, if such a function is specified.cookiep A pointer to the first ddi_dma_cookie(9S)
structure. ccountp Upon a successful return, ccountp points to a value representing the number of cookies for this DMA object.DESCRIPTION
ddi_dma_addr_bind_handle() allocates DMA resources for a
memory object such that a device can perform DMA to or from the object. DMA resources are allocated considering thedevice's DMA attributes as expressed by ddi_dma_attr(9S)
(see ddi_dma_alloc_handle(9F)).
ddi_dma_addr_bind_handle() fills in the first DMA cookie
pointed to by cookiep with the appropriate address, length, and bus type. *ccountp is set to the number of DMA cookies representing this DMA object. Subsequent DMA cookies must beSunOS 5.11 Last change: 26 Jul 1996 2
Kernel Functions for Drivers ddi_dma_addr_bind_handle(9F)
retrieved by calling ddi_dma_nextcookie(9F) the number of
times specified by *countp-1.
When a DMA transfer completes, the driver frees up systemDMA resources by calling ddi_dma_unbind_handle(9F).
The flags argument contains information for mapping rou-
tines.DDI_DMA_WRITE, DDI_DMA_READ, DDI_DMA_RDWR
These flags describe the intended direction of the DMA transfer.DDI_DMA_STREAMING
This flag should be set if the device is doing sequen-
tial, unidirectional, block-sized, and block-aligned
transfers to or from memory. The alignment and padding constraints specified by the minxfer and burstsizesfields in the DMA attribute structure, ddi_dma_attr(9S)
(see ddi_dma_alloc_handle(9F)) is used to allocate the
most effective hardware support for large transfers.DDI_DMA_CONSISTENT
This flag should be set if the device accesses memory randomly, or if synchronization steps usingddi_dma_sync(9F) need to be as efficient as possible.
I/O parameter blocks used for communication between a device and a driver should be allocated using
DDI_DMA_CONSISTENT.
DDI_DMA_REDZONE
If this flag is set, the system attempts to establish a protected red zone after the object. The DMA resource allocation functions do not guarantee the success of this request as some implementations may not have the hardware ability to support a red zone.DDI_DMA_PARTIAL
Setting this flag indicates the caller can accept resources for part of the object. That is, if the size of the object exceeds the resources available, onlySunOS 5.11 Last change: 26 Jul 1996 3
Kernel Functions for Drivers ddi_dma_addr_bind_handle(9F)
resources for a portion of the object are allocated. The system indicates this condition by returning statusDDI_DMA_PARTIAL_MAP. At a later point, the caller can
use ddi_dma_getwin(9F) to change the valid portion of
the object for which resources are allocated. If resources were allocated for only part of the object,ddi_dma_addr_bind_handle() returns resources for the
first DMAwindow. Even when DDI_DMA_PARTIAL is set, the
system may decide to allocate resources for the entireobject (less overhead) in which case DDI_DMA_MAPPED is
returned. 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, the caller does not
care if the allocation fails, and can handle an allocationfailure appropriately. If callback is set to DDI_DMA_SLEEP,
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 the address of a function to be called when resources become available. When the specified function is called, arg is passed to it as an argument. The specified callbackfunction must return either DDI_DMA_CALLBACK_RUNOUT or
DDI_DMA_CALLBACK_DONE. DDI_DMA_CALLBACK_RUNOUT indicates
that the callback function attempted to allocate DMA resources but failed. In this case, the callback function is put back on a list to be called again later.DDI_DMA_CALLBACK_DONE indicates that either the allocation
of DMA resources was successful or the driver no longer wishes to retry.The callback function is called in interrupt context. There-
fore, only system functions accessible from interrupt con-
text are be available. The callback function must take what-
ever steps are necessary to protect its critical resources, data structures, queues, and so on.RETURN VALUES
ddi_dma_addr_bind_handle() returns:
DDI_DMA_MAPPED Successfully allocated resources for
the entire object.DDI_DMA_PARTIAL_MAP Successfully allocated resources for
a part of the object. This is acceptable when partial transfers are permitted by setting theSunOS 5.11 Last change: 26 Jul 1996 4
Kernel Functions for Drivers ddi_dma_addr_bind_handle(9F)
DDI_DMA_PARTIAL flag in flags.
DDI_DMA_INUSE Another I/O transaction is using the
DMA handle.DDI_DMA_NORESOURCES No resources are available at the
present time.DDI_DMA_NOMAPPING The object cannot be reached by the
device requesting the resources.DDI_DMA_TOOBIG The object is too big. A request of
this size can never be satisfied on this particular system. The maximum size varies depending on machine and configuration.CONTEXT
ddi_dma_addr_bind_handle() can be called from user, kernel,
or interrupt context, except when callback is set toDDI_DMA_SLEEP, in which case it can only be called from user
or kernel context.SEE ALSO
ddi_dma_alloc_handle(9F), ddi_dma_free_handle(9F),
ddi_dma_getwin(9F), ddi_dma_mem_alloc(9F),
ddi_dma_mem_free(9F), ddi_dma_nextcookie(9F),
ddi_dma_sync(9F), ddi_dma_unbind_handle(9F),
ddi_umem_iosetup(9F), ddi_dma_attr(9S), ddi_dma_cookie(9S)
Writing Device Drivers NOTES If the driver permits partial mapping with theDDI_DMA_PARTIAL flag, the number of cookies in each window
may exceed the size of the device's scatter/gather list asspecified in the dma_attr_sgllen field in the
ddi_dma_attr(9S) structure. In this case, each set of cook-
ies comprising a DMA window will satisfy the DMA attributesas described in the ddi_dma_attr(9S) structure in all
aspects. The driver should set up its DMA engine and per-
form one transfer for each set of cookies sufficient for its scatter/gather list, up to the number of cookies for this window, before advancing to the next window usingddi_dma_getwin(9F).
SunOS 5.11 Last change: 26 Jul 1996 5