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path: root/drivers/ntb/ntb_transport.c
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2013-01-21NTB: Fix Sparse WarningsJon Mason
Address the sparse warnings and resulting fallout Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: Out of free receive entries issueJon Mason
If the NTB client driver enqueues the maximum number of rx buffers, it will not be able to re-enqueue another in its callback handler due to a lack of free entries. This can be avoided by adding the current entry to the free queue prior to calling the client callback handler. With this change, ntb_netdev will no longer encounter a rx error on its first packet. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: Remove reads across NTBJon Mason
CPU reads across NTB are slow(er) and can hang the local system if an ECC error is encountered on the remote. To work around the need for a read, have the remote side write its current position in the rx buffer to the local system's buffer and use that to see if there is room when transmitting. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: correct stack usage warning in debugfs_readJon Mason
Correct gcc warning of using too much stack debugfs_read. This is done by kmallocing the buffer instead of using the char array on stack. Also, shrinking the buffer to something closer to what is currently being used. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: whitespace cleanupsJon Mason
Whitespace cleanups found via `indent` Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: namespacecheck cleanupsJon Mason
Declare ntb_bus_type static to remove it from name space, and remove unused ntb_get_max_spads function. Found via `make namespacecheck`. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: use simple_open for debugfsJon Mason
Use simple_open for debugfs instead of recreating it in the NTB driver. Caught by coccicheck. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: No sleeping in interrupt contextJon Mason
Move all cancel_delayed_work_sync to a work thread to prevent sleeping in interrupt context (when the NTB link goes down). Caught via 'Sleep inside atomic section checking' Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: separate transmit and receive windowsJon Mason
Since it is possible for the memory windows on the two NTB connected systems to be different sizes, the divergent sizes must be accounted for in the segmentation of the MW's on each side. Create separate size variables and initialization as necessary. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: correct memory barrierJon Mason
mmiowb is not sufficient to flush the data and is causing data corruption. Change to wmb and the data corruption is no more. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: Handle ntb client device probes without present hardwareJon Mason
Attempts to probe client ntb drivers without ntb hardware present will result in null pointer dereference due to the lack of the ntb bus device being registers. Check to see if this is the case, and fail all calls by the clients registering their drivers. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17ntb: remove __dev* markingsGreg Kroah-Hartman
These are now gone from the kernel, so remove them from the newly-added drivers before they start to cause build errors for people. Cc: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17PCI-Express Non-Transparent Bridge SupportJon Mason
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 <jon.mason@intel.com> Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>