pdiag_dd_dma_complete

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AIX Version 4.3 Understanding the Diagnostic Subsystem for AIX

pdiag_dd_dma_complete

Purpose

The pdiag_dd_dma_complete() function unpins and detaches the user space DMA buffer. If the handle's dds.bus_type is set for the Micro Channel, this function also calls the d_complete() kernel service, which checks for detected IOCC errors, flushes the IOCC buffer (unhides it if necessary) and sets the page table 'modified' bit if the information was modified.

Syntax


#include <sys/pdiagex_dds.h>
int32 pdiag_dd_dma_complete( handle, daddr, operation )
pdiag_info_handle_t  handle; 
pdiag_addr_t  daddr;
uint32 operation;

Description

The following is performed by the pdiag_dd_dma_complete depending on the bus type and operation:

Where bus type = BUS_MICRO_CHANNEL and operation is PDIAG_DMA_MASTER or PDIAG_DMA_SLAVE

The pdiag_dd_dma_complete() function cleans up after the DMA transfer. First, the specified daddr is used to retrieve the baddr, count, and dma_flags specified in the corresponding pdiag_dd_dma_setup() calls. pdiag_dd_dma_complete() then issues the d_complete kernel call using these parameters. The user address space used for the DMA transfer is then unpinned, detached, and made available for another DMA transfer.
Where bus type = BUS_BID and operation is PDIAG_DMA_MASTER
The pdiag_dd_dma_complete() should be called after I/O completion involving the area mapped by the prior pdiag_dd_dma_setup() function call.
This function utilizes the D_UNMAP_PAGE macro to unmap the specified address.

Where bus type = BUS_BID and operation is PDIAG_DMA_SLAVE
The pdiag_dd_dma_complete() should be called after I/O completion involving the area mapped by the prior pdiag_dd_dma_setup() function call.
This function utilizes the D_UNMAP_SLAVE macro to unmap the specified address.

Execution Environment

The pdiag_dd_dma_complete() function can be called from the process or the interrupt environment on a BUS_MICRO_CHANNEL system. The function can only be called from the process environment on a BUS_BID system.

Parameters

handle	Points to pdiag_info_handle_t structure which is returned from pdiag_open().
daddr	The offset into the user's physical DMA address. This is returned by pdiag_dd_dma_setup () routine. For DMA slave completes, this should be set to 0.
operation	Type of operation to perform: PDIAG_DMA_MASTER PDIAG_DMA_SLAVE

Return Value

The pdiag_dd_dma_complete function returns one of the following values:

DGX_OK	The operation was successful. The errno is not set.
DGX_INVALID_HANDLE	Specified handle has been closed or was not generated by the pdiag_open() call. The errno is not set.
DGX_BADVAL_FAIL	daddr value was not valid. The errno is not set.
DGX_DCOMPLETE_FAIL	Application received a DMA error detected by the system hardware. The errno is set to the d_complete() return code.
DGX_UNPINU_FAIL	Application could not unpin the specified user buffer. The errno is set to the unpinu() return code.
DGX_XMDETACH_FAIL	Application could not detach user space from the physical address. The errno is set to the xmdetach() return code.

Related Information

pdiag_dd_dma_setup() and pdiag_dd_dma_enable() functions.

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