pciconfig_write (2)
Leading comments
Contributed by Niki A. Rahimi, LTC Security Development narahimi@us.ibm.com %%%LICENSE_START(FREELY_REDISTRIBUTABLE) May be freely distributed and modified. %%%LICENSE_END
NAME
pciconfig_read, pciconfig_write, pciconfig_iobase - pci device information handlingSYNOPSIS
#include <pci.h>
int pciconfig_read(unsigned long bus, unsigned long dfn,
unsigned long off, unsigned long len, void *buf);
int pciconfig_write(unsigned long bus, unsigned long dfn,
unsigned long off, unsigned long len, void *buf);
int pciconfig_iobase(long which, unsigned long bus,
unsigned long devfn);
DESCRIPTION
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.
RETURN VALUE
- pciconfig_read()
- On success, zero is returned. On error, -1 is returned and errno is set appropriately.
- pciconfig_write()
- On success, zero is returned. On error, -1 is returned and errno is set appropriately.
- 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.
ERRORS
- 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().