0001 .. SPDX-License-Identifier: GPL-2.0
0002
0003 =================
0004 PCI vNTB Function
0005 =================
0006
0007 :Author: Frank Li <Frank.Li@nxp.com>
0008
0009 The difference between PCI NTB function and PCI vNTB function is
0010
0011 PCI NTB function need at two endpoint instances and connect HOST1
0012 and HOST2.
0013
0014 PCI vNTB function only use one host and one endpoint(EP), use NTB
0015 connect EP and PCI host
0016
0017 .. code-block:: text
0018
0019
0020 +------------+ +---------------------------------------+
0021 | | | |
0022 +------------+ | +--------------+
0023 | NTB | | | NTB |
0024 | NetDev | | | NetDev |
0025 +------------+ | +--------------+
0026 | NTB | | | NTB |
0027 | Transfer | | | Transfer |
0028 +------------+ | +--------------+
0029 | | | | |
0030 | PCI NTB | | | |
0031 | EPF | | | |
0032 | Driver | | | PCI Virtual |
0033 | | +---------------+ | NTB Driver |
0034 | | | PCI EP NTB |<------>| |
0035 | | | FN Driver | | |
0036 +------------+ +---------------+ +--------------+
0037 | | | | | |
0038 | PCI BUS | <-----> | PCI EP BUS | | Virtual PCI |
0039 | | PCI | | | BUS |
0040 +------------+ +---------------+--------+--------------+
0041 PCI RC PCI EP
0042
0043 Constructs used for Implementing vNTB
0044 =====================================
0045
0046 1) Config Region
0047 2) Self Scratchpad Registers
0048 3) Peer Scratchpad Registers
0049 4) Doorbell (DB) Registers
0050 5) Memory Window (MW)
0051
0052
0053 Config Region:
0054 --------------
0055
0056 It is same as PCI NTB Function driver
0057
0058 Scratchpad Registers:
0059 ---------------------
0060
0061 It is appended after Config region.
0062
0063 .. code-block:: text
0064
0065
0066 +--------------------------------------------------+ Base
0067 | |
0068 | |
0069 | |
0070 | Common Config Register |
0071 | |
0072 | |
0073 | |
0074 +-----------------------+--------------------------+ Base + span_offset
0075 | | |
0076 | Peer Span Space | Span Space |
0077 | | |
0078 | | |
0079 +-----------------------+--------------------------+ Base + span_offset
0080 | | | + span_count * 4
0081 | | |
0082 | Span Space | Peer Span Space |
0083 | | |
0084 +-----------------------+--------------------------+
0085 Virtual PCI Pcie Endpoint
0086 NTB Driver NTB Driver
0087
0088
0089 Doorbell Registers:
0090 -------------------
0091
0092 Doorbell Registers are used by the hosts to interrupt each other.
0093
0094 Memory Window:
0095 --------------
0096
0097 Actual transfer of data between the two hosts will happen using the
0098 memory window.
0099
0100 Modeling Constructs:
0101 ====================
0102
0103 32-bit BARs.
0104
0105 ====== ===============
0106 BAR NO CONSTRUCTS USED
0107 ====== ===============
0108 BAR0 Config Region
0109 BAR1 Doorbell
0110 BAR2 Memory Window 1
0111 BAR3 Memory Window 2
0112 BAR4 Memory Window 3
0113 BAR5 Memory Window 4
0114 ====== ===============
0115
0116 64-bit BARs.
0117
0118 ====== ===============================
0119 BAR NO CONSTRUCTS USED
0120 ====== ===============================
0121 BAR0 Config Region + Scratchpad
0122 BAR1
0123 BAR2 Doorbell
0124 BAR3
0125 BAR4 Memory Window 1
0126 BAR5
0127 ====== ===============================
0128
0129
