Understanding the Diagnostic Subsystem for AIX

pdiag_pcicfg_read

Purpose

Reads a PCI Configuration register.

Syntax

#include <sys/pdiagex_dds.h>
#include <sys/pdiag_def.h>

int32 pdiag_pcicfg_read( device_instance, reg_offset, datasize, data )

pdiag_addr_t         device_instance;
ulong                reg_offset;
int                  datasize;
uchar                *data;

Description

The pdiag_pcicfg_read() function reads 8, 16, or 32 bits of a PCI Configuration register for this particular resource. The reg_offset parameter contains the register offset into the device's PCI configuration table. The calling application must provide a valid register offset before calling pdiag_pcicfg_read. The returned data is the 8, 16, or 32 bit value read from the PCI register configuration table. All the byte swapping required is performed internally by this function; the calling application must not alter the byte positioning of the data.

Execution Environment

The pdiag_pcicfg_read() function can be called from the process environment only.

Parameters

Parameter	Description
device_instance	Pointer to the string name of the specific device to read.
reg_offset	Contains the offset within the PCI configuration table register to be read.
datasize	The data size will be specified as follows: Size Type 8 bits IOCHAR8 16 bits IOSHORT16 32 bits IOLONG32
data	Pointer to the data to be read within the PCI Configuration Table. Note The value read is the specified size on the datasize parameter.

Return Value

The pdiag_pcicfg_read function returns one of the following values:

Return Value	Description
0	Successful return
-1	Software error

Related Information

The pdiag_pcicfg_write() function.