pci_request_region_exclusive — Reserved PCI I/O and memory resource
int pci_request_region_exclusive ( | struct pci_dev * pdev, |
| int bar, | |
const char * res_name); |
struct pci_dev * pdevPCI device whose resources are to be reserved
int barBAR to be reserved
const char * res_nameName to be associated with resource.
Mark the PCI region associated with PCI device pdev BR bar as
being reserved by owner res_name. Do not access any
address inside the PCI regions unless this call returns
successfully.
Returns 0 on success, or EBUSY on error. A warning
message is also printed on failure.
The key difference that _exclusive makes it that userspace is explicitly not allowed to map the resource via /dev/mem or sysfs.