pci_request_region_exclusive — Reserved PCI I/O and memory resource
|struct pci_dev * pdev,|
|const char * res_name|
struct pci_dev * pdev
PCI device whose resources are to be reserved
BAR to be reserved
const char * res_name
Name to be associated with resource.
Mark the PCI region associated with PCI device
being reserved by owner
res_name. Do not access any
address inside the PCI regions unless this call returns
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.