From 8b078c603249239f597dc395ac182667c8e0af9c Mon Sep 17 00:00:00 2001 From: Mathias Koehrer Date: Tue, 9 Aug 2016 10:33:31 +0200 Subject: PCI: Update "pci=resource_alignment" documentation Some uio based PCI drivers, e.g., uio_cif, do not work if the assigned PCI memory resources are not page aligned. By using the kernel option "pci=resource_alignment=@:." it is possible to request page alignment for memory resources of devices. However, this is cumbersome when using several devices, and the bus/slot/func addresses may change if devices are added to or removed from the system. Extend the "pci=resource_alignment" option so we can specify the relevant devices via PCI vendor, device, subvendor, and subdevice IDs. The specification of the devices via IDs is indicated by a leading string "pci:" as argument to "pci=resource_alignment". The format of the specification is pci::[::] Examples: pci=resource_alignment=4096@pci:8086:9c22:103c:198f pci=resource_alignment=pci:8086:9c22 # defaults to PAGE_SIZE align [bhelgaas: changelog, use actual vendor/device IDs in examples] Signed-off-by: Mathias Koehrer Signed-off-by: Bjorn Helgaas --- Documentation/kernel-parameters.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 46c030a49186..a4f4d693e2c1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3032,6 +3032,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. PAGE_SIZE is used as alignment. PCI-PCI bridge can be specified, if resource windows need to be expanded. + To specify the alignment for several + instances of a device, the PCI vendor, + device, subvendor, and subdevice may be + specified, e.g., 4096@pci:8086:9c22:103c:198f ecrc= Enable/disable PCIe ECRC (transaction layer end-to-end CRC checking). bios: Use BIOS/firmware settings. This is the -- cgit v1.2.3-59-g8ed1b