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pciconfig_read, pciconfig_write, pciconfig_iobase - pci device information handling
#include <pci.h> int pciconfig_read(unsigned long bus, unsigned long dfn, unsigned long off, unsigned long len, unsigned char *buf); int pciconfig_write(unsigned long bus, unsigned long dfn, unsigned long off, unsigned long len, unsigned char *buf); int pciconfig_iobase(int which, unsigned long bus, unsigned long devfn);
Most of the interaction with PCI devices is already handled by the kernel PCI layer, and thus these calls should not normally need to be accessed from user space. pciconfig_read() Reads to buf from device dev at offset off value. pciconfig_write() Writes from buf to device dev at offset off value. pciconfig_iobase() You pass it a bus/devfn pair and get a physical address for either the memory offset (for things like prep, this is 0xc0000000), the IO base for PIO cycles, or the ISA holes if any.
pciconfig_read() On success, zero is returned. On error, -1 is returned and errno is set to indicate the error. pciconfig_write() On success, zero is returned. On error, -1 is returned and errno is set to indicate the error. pciconfig_iobase() Returns information on locations of various I/O regions in physical memory according to the which value. Values for which are: IOBASE_BRIDGE_NUMBER, IOBASE_MEMORY, IOBASE_IO, IOBASE_ISA_IO, IOBASE_ISA_MEM.
EINVAL len value is invalid. This does not apply to pciconfig_iobase(). EIO I/O error. ENODEV For pciconfig_iobase(), "hose" value is NULL. For the other calls, could not find a slot. ENOSYS The system has not implemented these calls (CONFIG_PCI not defined). EOPNOTSUPP This return value is valid only for pciconfig_iobase(). It is returned if the value for which is invalid. EPERM User does not have the CAP_SYS_ADMIN capability. This does not apply to pciconfig_iobase().
These calls are Linux-specific, available since Linux 2.0.26/2.1.11.
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