From fce8a7bb5b4bfb8a27324703fd5b002ee9247e90 Mon Sep 17 00:00:00 2001 From: Jon Mason Date: Fri, 16 Nov 2012 19:27:12 -0700 Subject: PCI-Express Non-Transparent Bridge Support A PCI-Express non-transparent bridge (NTB) is a point-to-point PCIe bus connecting 2 systems, providing electrical isolation between the two subsystems. A non-transparent bridge is functionally similar to a transparent bridge except that both sides of the bridge have their own independent address domains. The host on one side of the bridge will not have the visibility of the complete memory or I/O space on the other side of the bridge. To communicate across the non-transparent bridge, each NTB endpoint has one (or more) apertures exposed to the local system. Writes to these apertures are mirrored to memory on the remote system. Communications can also occur through the use of doorbell registers that initiate interrupts to the alternate domain, and scratch-pad registers accessible from both sides. The NTB device driver is needed to configure these memory windows, doorbell, and scratch-pad registers as well as use them in such a way as they can be turned into a viable communication channel to the remote system. ntb_hw.[ch] determines the usage model (NTB to NTB or NTB to Root Port) and abstracts away the underlying hardware to provide access and a common interface to the doorbell registers, scratch pads, and memory windows. These hardware interfaces are exported so that other, non-mainlined kernel drivers can access these. ntb_transport.[ch] also uses the exported interfaces in ntb_hw.[ch] to setup a communication channel(s) and provide a reliable way of transferring data from one side to the other, which it then exports so that "client" drivers can access them. These client drivers are used to provide a standard kernel interface (i.e., Ethernet device) to NTB, such that Linux can transfer data from one system to the other in a standard way. Signed-off-by: Jon Mason Reviewed-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- MAINTAINERS | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index 915564eda145..c5d675a8c53d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5394,6 +5394,12 @@ S: Maintained F: Documentation/scsi/NinjaSCSI.txt F: drivers/scsi/nsp32* +NTB DRIVER +M: Jon Mason +S: Supported +F: drivers/ntb/ +F: include/linux/ntb.h + NTFS FILESYSTEM M: Anton Altaparmakov L: linux-ntfs-dev@lists.sourceforge.net -- cgit v1.2.3 From 548c237c0a9972df5d1afaca38aa733ee577128d Mon Sep 17 00:00:00 2001 From: Jon Mason Date: Fri, 16 Nov 2012 19:27:13 -0700 Subject: net: Add support for NTB virtual ethernet device A virtual ethernet device that uses the NTB transport API to send/receive data. Signed-off-by: Jon Mason Reviewed-by: Nicholas Bellinger Acked-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- MAINTAINERS | 1 + 1 file changed, 1 insertion(+) (limited to 'MAINTAINERS') diff --git a/MAINTAINERS b/MAINTAINERS index c5d675a8c53d..01bee6aadb48 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5398,6 +5398,7 @@ NTB DRIVER M: Jon Mason S: Supported F: drivers/ntb/ +F: drivers/net/ntb_netdev.c F: include/linux/ntb.h NTFS FILESYSTEM -- cgit v1.2.3