pci_request_region_exclusive (9) - Linux Manuals

pci_request_region_exclusive: Reserved PCI I/O and memory resource

Command to display pci_request_region_exclusive manual in Linux: $ man 9 pci_request_region_exclusive

NAME

pci_request_region_exclusive - Reserved PCI I/O and memory resource

SYNOPSIS

int pci_request_region_exclusive(struct pci_dev * pdev, int bar, const char * res_name);

ARGUMENTS

pdev

: PCI device whose resources are to be reserved

bar

: BAR to be reserved

res_name

: Name to be associated with resource.

DESCRIPTION

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.