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path: root/drivers/ntb/ntb_transport.c
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2013-11-13NTB: Correct debugfs to work with more than 1 NTB DeviceJon Mason
commit 1517a3f21a1dd321f16bcf44204bddff9d21abd0 upstream. Debugfs was setup in NTB to only have a single debugfs directory. This resulted in the leaking of debugfs directories and files when multiple NTB devices were present, due to each device stomping on the variables containing the previous device's values (thus preventing them from being freed on cleanup). Correct this by creating a secondary directory of the PCI BDF for each device present, and nesting the previously existing information in those directories. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-15NTB: Multiple NTB client fixJon Mason
Fix issue with adding multiple ntb client devices to the ntb virtual bus. Previously, multiple devices would be added with the same name, resulting in crashes. To get around this issue, add a unique number to the device when it is added. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15NTB: memcpy lockup workaroundJon Mason
The system will appear to lockup for long periods of time due to the NTB driver spending too much time in memcpy. Avoid this by reducing the number of packets that can be serviced on a given interrupt. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15NTB: Correctly handle receive buffers of the minimal sizeJon Mason
The ring logic of the NTB receive buffer/transmit memory window requires there to be at least 2 payload sized allotments. For the minimal size case, split the buffer into two and set the transport_mtu to the appropriate size. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15NTB: reset tx_index on link toggleJon Mason
If the NTB link toggles, the driver could stop receiving due to the tx_index not being set to 0 on the transmitting size on a link-up event. This is due to the driver expecting the incoming data to start at the beginning of the receive buffer and not at a random place. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15NTB: Link toggle memory leakJon Mason
Each link-up will allocate a new NTB receive buffer when the NTB properties are negotiated with the remote system. These allocations did not check for existing buffers and thus did not free them. Now, the driver will check for an existing buffer and free it if not of the correct size, before trying to alloc a new one. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15NTB: Handle 64bit BAR sizesJon Mason
64bit BAR sizes are permissible with an NTB device. To support them various modifications and clean-ups were required, most significantly using 2 32bit scratch pad registers for each BAR. Also, modify the driver to allow more than 2 Memory Windows. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15NTB: fix pointer math issuesDan Carpenter
->remote_rx_info and ->rx_info are struct ntb_rx_info pointers. If we add sizeof(struct ntb_rx_info) then it goes too far. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15NTB: variable dereferenced before checkJon Mason
Correct instances of variable dereferencing before checking its value on the functions exported to the client drivers. Also, add sanity checks for all exported functions. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jon Mason <jon.mason@intel.com>
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>