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path: root/drivers/ntb
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2013-11-20NTB: Fix NTB-RP Link UpJon Mason1-8/+28
The Xeon NTB-RP setup, the transparent side does not get a link up/down interrupt. Since the presence of a NTB device on the transparent side means that we have a NTB link up, we can work around the lack of an interrupt by simply calling the link up function to notify the upper layers. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-11-20NTB: Xeon Doorbell errata workaroundJon Mason2-5/+16
Modifications to the 14th bit of the B2BDOORBELL register will not be mirrored to the remote system due to a hardware issue. To get around the issue, shrink the number of available doorbell bits by 1. The max number of doorbells was being used as a way to referencing the Link Doorbell bit. Since this would no longer work, the driver must now explicitly reference that bit. This does not affect the xeon_errata_workaround case, as it is not using the b2bdoorbell register. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05ntb: clean up unnecessary MSI/MSI-X capability findYijing Wang1-4/+3
PCI core will initialize device MSI/MSI-X capability in pci_msi_init_pci_dev(). So device driver should use pci_dev->msi_cap/msix_cap to determine whether the device support MSI/MSI-X instead of using pci_find_capability(pci_dev, PCI_CAP_ID_MSI/MSIX). Access to PCIe device config space again will consume more time. Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05NTB: Update VersionJon Mason1-1/+1
Update NTB version to 1.0 Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05NTB: Comment FixJon Mason2-4/+5
Add "data" ntb_register_db_callback parameter description comment and correct poor spelling. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05NTB: Remove unused variableJon Mason1-3/+0
Remove unused pci_dev variable from ntb_transport_free() Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05NTB: Remove References of non-B2B BWD HWJon Mason2-13/+4
NTB-RP is not a supported configuration on BWD hardware. Remove the code attempting to set it up. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05NTB: NTB-RP supportJon Mason2-104/+163
Add support for Non-Transparent Bridge connected to a PCI-E Root Port on the remote system (also known as NTB-RP mode). This allows for a NTB enabled system to be connected to a non-NTB enabled system/slot. Modifications to the registers and BARs/MWs on the Secondary side by the remote system are reflected into registers on the Primary side for the local system. Similarly, modifications of registers and BARs/MWs on Primary side by the local system are reflected into registers on the Secondary side for the Remote System. This allows communication between the 2 sides via these registers and BARs/MWs. Note: there is not a fix for the Xeon Errata (that was already worked around in NTB-B2B mode) for NTB-RP mode. Due to this limitation, NTB-RP will not work on the Secondary side with the Xeon Errata workaround enabled. To get around this, disable the workaround via the xeon_errata_workaround=0 modparm. However, this can cause the hang described in the errata. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05NTB: Rename Variables for NTB-RPJon Mason3-49/+48
Many variable names in the NTB driver refer to the primary or secondary side. However, these variables will be used to access the reverse case when in NTB-RP mode. Make these names more generic in anticipation of NTB-RP support. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05NTB: Use DMA Engine to Transmit and ReceiveJon Mason3-47/+295
Allocate and use a DMA engine channel to transmit and receive data over NTB. If none is allocated, fall back to using the CPU to transfer data. Signed-off-by: Jon Mason <jon.mason@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
2013-09-03NTB: Enable 32bit SupportJon Mason3-4/+19
Correct the issues on NTB that prevented it from working on x86_32 and modify the Kconfig to allow it to be permitted to be used in that environment as well. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-03NTB: Update Device IDsJon Mason2-14/+30
Add support for new Intel NTB devices on upcoming Xeon hardware. Since the Xeon hardware design is already in place in the driver, all that is needed are the new device ids. Remove the device IDs for NTB devs running in Transparent Bridge mode, as this driver is not being used for those devices. Rename the device IDs for NTB devs running in NTB-RP mode to better identify their usage model. "PS" to denote the Primary Side of NTB, and "SS" to denote the secondary side. The primary side is the interface exposed to the local system, and the secondary side is the interface exposed to the remote system. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-03NTB: BWD Link RecoveryJon Mason3-3/+127
The BWD NTB device will drop the link if an error is encountered on the point-to-point PCI bridge. The link will stay down until all errors are cleared and the link is re-established. On link down, check to see if the error is detected, if so do the necessary housekeeping to try and recover from the error and reestablish the link. There is a potential race between the 2 NTB devices recovering at the same time. If the times are synchronized, the link will not recover and the driver will be stuck in this loop forever. Add a random interval to the recovery time to prevent this race. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-03NTB: Xeon Errata WorkaroundJon Mason4-58/+193
There is a Xeon hardware errata related to writes to SDOORBELL or B2BDOORBELL in conjunction with inbound access to NTB MMIO Space, which may hang the system. To workaround this issue, use one of the memory windows to access the interrupt and scratch pad registers on the remote system. This bypasses the issue, but removes one of the memory windows from use by the transport. This reduction of MWs necessitates adding some logic to determine the number of available MWs. Since some NTB usage methodologies may have unidirectional traffic, the ability to disable the workaround via modparm has been added. See BF113 in http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-c5500-c3500-spec-update.pdf See BT119 in http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e5-family-spec-update.pdf Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-03NTB: Correct debugfs to work with more than 1 NTB DeviceJon Mason3-12/+48
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>
2013-09-03NTB: Correct USD/DSD IdentificationJon Mason1-2/+5
Due to ambiguous documentation, the USD/DSD identification is backward when compared to the setting in BIOS. Correct the bits to match the BIOS setting. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-03NTB: Correct Number of Scratch Pad RegistersJon Mason2-3/+3
The NTB Xeon hardware has 16 scratch pad registers and 16 back-to-back scratch pad registers. Correct the #define to represent this and update the variable names to reflect their usage. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-03NTB: Add Error Handling in ntb_device_setupJon Mason1-1/+4
If an error is encountered in ntb_device_setup, it is possible that the spci_cmd isn't populated. Writes to the offset can result in a NULL pointer dereference. This issue is easily encountered by running in NTB-RP mode, as it currently is not supported and will generate an error. To get around this issue, return if an error is encountered prior to attempting to write to the spci_cmd offset. Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15NTB: Multiple NTB client fixJon Mason1-2/+3
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 Mason1-3/+8
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 Mason1-3/+5
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 Mason1-1/+1
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 Mason1-12/+20
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 Mason2-50/+75
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 Carpenter1-2/+2
->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: off by one sanity checksDan Carpenter1-3/+3
These tests are off by one. If "mw" is equal to NTB_NUM_MW then we would go beyond the end of the ndev->mw[] array. 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 Mason1-2/+14
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 Mason3-20/+20
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>
2013-01-21NTB: disable x86_32 supportJon Mason1-1/+1
Atomic readq and writeq do not exist by default on some 32bit architectures, thus causing compile errors due to non-existent symbols. Since NTB has not been tested 32bit, disable x86_32 support until such time as this and any other issues can be properly discovered. Signed-off-by: Jon Mason <jon.mason@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-20NTB: Update VersionJon Mason1-1/+1
Update NTB version to 0.25 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 Mason1-3/+6
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 Mason1-74/+63
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 Mason1-3/+10
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 Mason1-24/+16
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 Mason2-15/+1
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 Mason1-7/+1
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 Mason1-3/+17
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 Mason1-35/+44
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 Mason1-1/+1
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 Mason1-0/+6
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-Hartman2-11/+9
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 Mason6-0/+2920
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>
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