path: root/usr/src/man/man9f/ddi_dma_addr_bind_handle.9f

'\" te
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.TH DDI_DMA_ADDR_BIND_HANDLE 9F "Jan 18, 2020"
.SH NAME
ddi_dma_addr_bind_handle \- binds an address to a DMA handle
.SH SYNOPSIS
.nf
#include <sys/ddi.h>
#include <sys/sunddi.h>



\fBint\fR \fBddi_dma_addr_bind_handle\fR(\fBddi_dma_handle_t\fR \fIhandle\fR, \fBstruct as *\fR\fIas\fR,
     \fBcaddr_t\fR \fIaddr\fR, \fBsize_t\fR \fIlen\fR, \fBuint_t\fR \fIflags\fR, \fBint (*\fR\fIcallback\fR) (caddr_t) ,
     \fBcaddr_t\fR \fIarg\fR, \fBddi_dma_cookie_t *\fR\fIcookiep\fR, \fBuint_t *\fR\fIccountp\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI).
.SH PARAMETERS
.ne 2
.na
\fB\fIhandle\fR \fR
.ad
.RS 13n
The  \fBDMA\fR handle previously allocated by a call to
\fBddi_dma_alloc_handle\fR(9F).
.RE

.sp
.ne 2
.na
\fB\fIas\fR \fR
.ad
.RS 13n
A pointer to an address space structure. This parameter should be set to
\fINULL\fR, which implies kernel address space.
.RE

.sp
.ne 2
.na
\fB\fIaddr\fR \fR
.ad
.RS 13n
Virtual address of the memory object.
.RE

.sp
.ne 2
.na
\fB\fIlen\fR \fR
.ad
.RS 13n
Length of the memory object in bytes.
.RE

.sp
.ne 2
.na
\fB\fIflags\fR \fR
.ad
.RS 13n
Valid flags include:
.sp
.ne 2
.na
\fB\fBDDI_DMA_WRITE\fR \fR
.ad
.RS 23n
Transfer direction is from memory to I/O.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_READ\fR \fR
.ad
.RS 23n
Transfer direction is from I/O to memory.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_RDWR\fR \fR
.ad
.RS 23n
Both read and write.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_REDZONE\fR \fR
.ad
.RS 23n
Establish an \fBMMU\fR redzone at end of the object.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_PARTIAL\fR \fR
.ad
.RS 23n
Partial resource allocation.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_CONSISTENT\fR \fR
.ad
.RS 23n
Nonsequential, random, and small block transfers.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_STREAMING\fR \fR
.ad
.RS 23n
Sequential, unidirectional, block-sized, and block-aligned transfers.
.RE

.RE

.sp
.ne 2
.na
\fB\fIcallback\fR \fR
.ad
.RS 13n
The address of a function to call back later if resources are not currently
available. The following special function addresses may also  be used.
.sp
.ne 2
.na
\fB\fBDDI_DMA_SLEEP\fR \fR
.ad
.RS 21n
Wait until resources are available.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_DONTWAIT\fR \fR
.ad
.RS 21n
Do not wait until resources are available and do not schedule a callback.
.RE

.RE

.sp
.ne 2
.na
\fB\fIarg\fR \fR
.ad
.RS 13n
Argument to be passed to the callback function,  \fIcallback\fR, if such a
function is specified.
.RE

.sp
.ne 2
.na
\fB\fIcookiep\fR \fR
.ad
.RS 13n
A pointer to the first \fBddi_dma_cookie\fR(9S) structure.  This should
be left as \fBNULL\fR in new callers.
.RE

.sp
.ne 2
.na
\fB\fIccountp\fR \fR
.ad
.RS 13n
Upon a successful return,  \fIccountp\fR points to a value representing the
number of cookies for this \fBDMA\fR object.  This can
be left as \fBNULL\fR in new callers.  The cookie count can be obtained
by calling \fBddi_dma_ncookies\fR(9F).
.RE

.SH DESCRIPTION
\fBddi_dma_addr_bind_handle()\fR allocates \fBDMA\fR resources for a memory
object  such that a device can perform \fBDMA\fR to or from the object.
\fBDMA\fR resources are allocated considering the device's \fBDMA\fR attributes
as expressed by \fBddi_dma_attr\fR(9S) (see \fBddi_dma_alloc_handle\fR(9F)).
.sp
.LP
\fBddi_dma_addr_bind_handle()\fR allocates and associates a number of
\fBDMA\fR cookies with \fIhandle\fR.  To get the total number of
cookies, callers should use the \fBddi_dma_ncookies\fR(9F) function. To
get all of the cookies, callers should use the
\fBddi_dma_cookie_iter\fR(9F) or \fBddi_dma_cookie_get\fR(9F) functions.
Callers should pass \fBNULL\fR for \fIcookiep\fR and \fIccountp\fR.
These values are required if using the deprecated
\fBddi_dma_nextcookie\fR(9F) interface, in which case \fIcookiep\fR is
filled in with the first \fBddi_dma_cookie\fR(9S) structure.
.sp
.LP
When a \fBDMA\fR transfer completes, the driver frees up system \fBDMA\fR
resources by calling \fBddi_dma_unbind_handle\fR(9F).
.sp
.LP
The \fIflags\fR argument contains information for mapping routines.
.sp
.ne 2
.na
\fB\fBDDI_DMA_WRITE\fR, \fBDDI_DMA_READ\fR, \fBDDI_DMA_RDWR\fR\fR
.ad
.sp .6
.RS 4n
These flags describe the intended direction of the \fBDMA\fR transfer.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_STREAMING\fR \fR
.ad
.sp .6
.RS 4n
This flag should be set if the device is doing sequential, unidirectional,
block-sized, and block-aligned transfers to or from memory.  The alignment and
padding constraints specified by the \fBminxfer\fR and \fBburstsizes\fR fields
in the \fBDMA\fR attribute structure, \fBddi_dma_attr\fR(9S) (see
\fBddi_dma_alloc_handle\fR(9F)) is used to allocate the most effective hardware
support for large transfers.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_CONSISTENT\fR \fR
.ad
.sp .6
.RS 4n
This flag should be set if  the device accesses memory randomly, or if
synchronization steps using \fBddi_dma_sync\fR(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 \fBDDI_DMA_CONSISTENT\fR.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_REDZONE\fR \fR
.ad
.sp .6
.RS 4n
If this flag is set, the system attempts to  establish a protected red zone
after the object. The \fBDMA\fR 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.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_PARTIAL\fR \fR
.ad
.sp .6
.RS 4n
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 \fBDDI_DMA_PARTIAL_MAP\fR. At a later point,
the caller can use \fBddi_dma_getwin\fR(9F) to change the valid portion of the
object for which resources are allocated. If resources were allocated for only
part of the object, \fBddi_dma_addr_bind_handle()\fR returns resources for the
first \fBDMA\fRwindow. Even when \fBDDI_DMA_PARTIAL\fR is set, the system may
decide to allocate resources for the entire object (less overhead) in which
case \fBDDI_DMA_MAPPED\fR is returned.
.RE

.sp
.LP
The callback function \fIcallback\fR indicates how a caller wants to handle the
possibility of resources not being available. If \fIcallback\fR is set to
\fBDDI_DMA_DONTWAIT\fR, the caller does not care if the allocation fails, and
can handle an allocation failure appropriately. If \fIcallback\fR is set to
\fBDDI_DMA_SLEEP\fR, the caller wishes to have the allocation routines wait for
resources to become available. If any other value is set and a \fBDMA\fR
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,  \fIarg\fR is passed to it as an argument. The specified
callback function must  return either \fBDDI_DMA_CALLBACK_RUNOUT\fR or
\fBDDI_DMA_CALLBACK_DONE\fR. \fBDDI_DMA_CALLBACK_RUNOUT\fR indicates that the
callback function attempted to allocate \fBDMA\fR resources but failed.  In
this case, the callback function is put back on a list to be called again
later. \fBDDI_DMA_CALLBACK_DONE\fR indicates that either the allocation of
\fBDMA\fR resources was successful or the driver no longer wishes to retry.
.sp
.LP
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.
.SH RETURN VALUES
\fBddi_dma_addr_bind_handle()\fR returns:
.sp
.ne 2
.na
\fB\fBDDI_DMA_MAPPED\fR \fR
.ad
.RS 24n
Successfully allocated resources for the entire object.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_PARTIAL_MAP\fR \fR
.ad
.RS 24n
Successfully allocated resources for a part of the object. This is acceptable
when partial transfers are permitted by setting the \fBDDI_DMA_PARTIAL\fR flag
in \fIflags\fR.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_INUSE\fR \fR
.ad
.RS 24n
Another I/O transaction is using the \fBDMA\fR handle.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_NORESOURCES\fR \fR
.ad
.RS 24n
No resources are available at the present time.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_NOMAPPING\fR \fR
.ad
.RS 24n
The object cannot be reached by the device requesting the resources.
.RE

.sp
.ne 2
.na
\fB\fBDDI_DMA_TOOBIG\fR \fR
.ad
.RS 24n
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.
.RE

.SH CONTEXT
\fBddi_dma_addr_bind_handle()\fR can be called from user, kernel, or interrupt
context, except when \fIcallback\fR is set to  \fBDDI_DMA_SLEEP\fR, in which
case it can only be called from user or kernel context.
.SH SEE ALSO
.BR ddi_dma_alloc_handle (9F),
.BR ddi_dma_cookie_get (9F),
.BR ddi_dma_cookie_iter (9F),
.BR ddi_dma_free_handle (9F),
.BR ddi_dma_getwin (9F),
.BR ddi_dma_mem_alloc (9F),
.BR ddi_dma_mem_free (9F),
.BR ddi_dma_ncookies (9F),
.BR ddi_dma_sync (9F),
.BR ddi_dma_unbind_handle (9F),
.BR ddi_umem_iosetup (9F),
.BR ddi_dma_attr (9S),
.BR ddi_dma_cookie (9S)
.sp
.LP
\fIWriting Device Drivers\fR
.SH NOTES
If the driver permits partial mapping with the  \fBDDI_DMA_PARTIAL\fR flag, the
number of cookies in each window may exceed the size of the device's
scatter/gather list as specified in the  \fBdma_attr_sgllen\fR field in the
\fBddi_dma_attr\fR(9S) structure. In this case, each set of cookies comprising
a  \fBDMA\fR window will satisfy the \fBDMA\fR attributes as described in the
\fBddi_dma_attr\fR(9S) structure in all aspects. The driver should set up its
\fBDMA\fR engine and perform 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 using \fBddi_dma_getwin\fR(9F).