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diff --git a/Documentation/PCI/endpoint/pci-vntb-function.rst b/Documentation/PCI/endpoint/pci-vntb-function.rst new file mode 100644 index 000000000..0c51f53ab --- /dev/null +++ b/Documentation/PCI/endpoint/pci-vntb-function.rst @@ -0,0 +1,129 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================= +PCI vNTB Function +================= + +:Author: Frank Li <Frank.Li@nxp.com> + +The difference between PCI NTB function and PCI vNTB function is + +PCI NTB function need at two endpoint instances and connect HOST1 +and HOST2. + +PCI vNTB function only use one host and one endpoint(EP), use NTB +connect EP and PCI host + +.. code-block:: text + + + +------------+ +---------------------------------------+ + | | | | + +------------+ | +--------------+ + | NTB | | | NTB | + | NetDev | | | NetDev | + +------------+ | +--------------+ + | NTB | | | NTB | + | Transfer | | | Transfer | + +------------+ | +--------------+ + | | | | | + | PCI NTB | | | | + | EPF | | | | + | Driver | | | PCI Virtual | + | | +---------------+ | NTB Driver | + | | | PCI EP NTB |<------>| | + | | | FN Driver | | | + +------------+ +---------------+ +--------------+ + | | | | | | + | PCI BUS | <-----> | PCI EP BUS | | Virtual PCI | + | | PCI | | | BUS | + +------------+ +---------------+--------+--------------+ + PCI RC PCI EP + +Constructs used for Implementing vNTB +===================================== + + 1) Config Region + 2) Self Scratchpad Registers + 3) Peer Scratchpad Registers + 4) Doorbell (DB) Registers + 5) Memory Window (MW) + + +Config Region: +-------------- + +It is same as PCI NTB Function driver + +Scratchpad Registers: +--------------------- + +It is appended after Config region. + +.. code-block:: text + + + +--------------------------------------------------+ Base + | | + | | + | | + | Common Config Register | + | | + | | + | | + +-----------------------+--------------------------+ Base + span_offset + | | | + | Peer Span Space | Span Space | + | | | + | | | + +-----------------------+--------------------------+ Base + span_offset + | | | + span_count * 4 + | | | + | Span Space | Peer Span Space | + | | | + +-----------------------+--------------------------+ + Virtual PCI Pcie Endpoint + NTB Driver NTB Driver + + +Doorbell Registers: +------------------- + + Doorbell Registers are used by the hosts to interrupt each other. + +Memory Window: +-------------- + + Actual transfer of data between the two hosts will happen using the + memory window. + +Modeling Constructs: +==================== + +32-bit BARs. + +====== =============== +BAR NO CONSTRUCTS USED +====== =============== +BAR0 Config Region +BAR1 Doorbell +BAR2 Memory Window 1 +BAR3 Memory Window 2 +BAR4 Memory Window 3 +BAR5 Memory Window 4 +====== =============== + +64-bit BARs. + +====== =============================== +BAR NO CONSTRUCTS USED +====== =============================== +BAR0 Config Region + Scratchpad +BAR1 +BAR2 Doorbell +BAR3 +BAR4 Memory Window 1 +BAR5 +====== =============================== + + |