Man Pages

---

Back to Software Index  Manpage Top Level

Name

Synopsis

int ddi_dma_addr_bind_handle(ddi_dma_handle_t handle, struct as *as, caddr_t addr, uint_t len, uint_t flags, int (*callback)(caddr_t), caddr_t arg, ddi_dma_cookie_t *cookiep, uint_t *ccountp);

Arguments

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 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 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.

Interface Level

Description

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 be retrieved by calling ddi_dma_nextcookie(9F) *countp - 1 times.

When a DMA transfer completes, the driver should free 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, unidirectional, block-sized, and block-aligned transfers to or from memory. 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 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, only resources for a portion of the object are allocated. The system indicates this condition 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 DMA window. Even when DDI_DMA_PARTIAL is set, the system 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 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_CALLBACK_RUNOUT or DDI_DMA_CALLBACK_DONE . DDI_DMA_CALLBACK_RUNOUT indicates that the callback function attempted to allocate DMA resources but failed to do so. In this case the callback function is put back on a list to be called again later. DDI_DMA_CALLBACK_DONE indicates either a successful allocation of DMA resources or that 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 necessary to protect its critical resources, data structures, queues, etc.

Return Values

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 system. The maximum size varies depending on machine and configuration.

Context

See Also

Table of Contents

• Name
• Synopsis
• Arguments
• Interface Level
• Description
• Return Values
• Context
• See Also