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ddi_dma_addr_bind_handle(9f)

Kernel Functions                                  ddi_dma_addr_bind_handle(9F)



NAME
       ddi_dma_addr_bind_handle - binds an address to a DMA handle

SYNOPSIS
       #include <sys/ddi.h>
       #include <sys/sunddi.h>

       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  call  to
                   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 allocation.


                   DDI_DMA_CONSISTENT    Nonsequential,  random,   and   small
                                         block transfers.


                   DDI_DMA_STREAMING     Sequential,   unidirectional,  block-
                                         sized, and block-aligned transfers.



       callback    The address of a function to call back later  if  resources
                   are not currently available. 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 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  repre‐
                   senting 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 the device'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.  Subse‐
       quent  DMA  cookies must be retrieved by calling ddi_dma_nextcookie(9F)
       the number of times specified by *countp-1.


       When a DMA transfer completes, the driver frees up system DMA resources
       by calling ddi_dma_unbind_handle(9F).


       The flags argument contains information for mapping routines.

       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 sequential, unidi‐
           rectional, block-sized, and block-aligned transfers to or from mem‐
           ory. The alignment and padding constraints specified by the minxfer
           and   burstsizes   fields   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 using ddi_dma_sync(9F) need to be as effi‐
           cient 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, only resources for a portion of the object are
           allocated. The system indicates this condition by returning  status
           DDI_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 sys‐
           tem may decide to allocate resources for the  entire  object  (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 allocation failure 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  speci‐
       fied function is called, arg is passed to it as an argument. The speci‐
       fied callback function must return  either  DDI_DMA_CALLBACK_RUNOUT  or
       DDI_DMA_CALLBACK_DONE. DDI_DMA_CALLBACK_RUNOUT indicates that the call‐
       back 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. Therefore, only
       system functions accessible from interrupt context  are  be  available.
       The callback function must take whatever 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   the
                              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  sys‐
                              tem.   The  maximum  size  varies  depending  on
                              machine and configuration.


CONTEXT
       ddi_dma_addr_bind_handle() can be called from user, kernel,  or  inter‐
       rupt  context,  except  when callback is set to DDI_DMA_SLEEP, in which
       case it can only be called from user or kernel context.

SEE ALSO
       ddi_dma_sync(9F),  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_unbind_handle(9F),
       ddi_umem_iosetup(9F), ddi_dma_attr(9S), ddi_dma_cookie(9S)


       Writing Device Drivers in Oracle Solaris 11.4

NOTES
       If  the  driver  permits partial mapping with the DDI_DMA_PARTIAL flag,
       the number of cookies in  each  window  may  exceed  the  size  of  the
       device's  scatter/gather list as specified in the dma_attr_sgllen field
       in the ddi_dma_attr(9S) structure. In this case, each  set  of  cookies
       comprising a DMA window will satisfy the DMA attributes as described in
       the ddi_dma_attr(9S) structure in all aspects. The driver should set up
       its  DMA engine and perform one transfer for each set of cookies suffi‐
       cient for its scatter/gather list, up to the number of cookies for this
       window, before advancing to the next window using ddi_dma_getwin(9F).



Oracle Solaris 11.4               26 Jul 1996
                                                  ddi_dma_addr_bind_handle(9F)
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