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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
->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>
