xref: /linux/Documentation/ABI/testing/sysfs-devices-pci-host-bridge (revision 249872f53d64441690927853e9d3af36394802d5)
1What:		/sys/devices/pciDDDD:BB
2		/sys/devices/.../pciDDDD:BB
3Contact:	linux-pci@vger.kernel.org
4Description:
5		A PCI host bridge device parents a PCI bus device topology. PCI
6		controllers may also parent host bridges. The DDDD:BB format
7		conveys the PCI domain (ACPI segment) number and root bus number
8		(in hexadecimal) of the host bridge. Note that the domain number
9		may be larger than the 16-bits that the "DDDD" format implies
10		for emulated host-bridges.
11
12What:		pciDDDD:BB/firmware_node
13Contact:	linux-pci@vger.kernel.org
14Description:
15		(RO) Symlink to the platform firmware device object "companion"
16		of the host bridge. For example, an ACPI device with an _HID of
17		PNP0A08 (/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00). See
18		/sys/devices/pciDDDD:BB entry for details about the DDDD:BB
19		format.
20
21What:		pciDDDD:BB/streamH.R.E
22Contact:	linux-pci@vger.kernel.org
23Description:
24		(RO) When a platform has established a secure connection, PCIe
25		IDE, between two Partner Ports, this symlink appears. A stream
26		consumes a Stream ID slot in each of the Host bridge (H), Root
27		Port (R) and Endpoint (E).  The link points to the Endpoint PCI
28		device in the Selective IDE Stream pairing. Specifically, "R"
29		and "E" represent the assigned Selective IDE Stream Register
30		Block in the Root Port and Endpoint, and "H" represents a
31		platform specific pool of stream resources shared by the Root
32		Ports in a host bridge. See /sys/devices/pciDDDD:BB entry for
33		details about the DDDD:BB format.
34
35What:		pciDDDD:BB/available_secure_streams
36Contact:	linux-pci@vger.kernel.org
37Description:
38		(RO) When a host bridge has Root Ports that support PCIe IDE
39		(link encryption and integrity protection) there may be a
40		limited number of Selective IDE Streams that can be used for
41		establishing new end-to-end secure links. This attribute
42		decrements upon secure link setup, and increments upon secure
43		link teardown. The in-use stream count is determined by counting
44		stream symlinks. See /sys/devices/pciDDDD:BB entry for details
45		about the DDDD:BB format.
46