xref: /linux/Documentation/driver-api/cxl/platform/example-configurations/one-dev-per-hb.rst (revision fb7399cf2d0b33825b8039f95c45395c7deba25c)
1.. SPDX-License-Identifier: GPL-2.0
2
3==========================
4One Device per Host Bridge
5==========================
6
7This system has a single socket with two CXL host bridges. Each host bridge
8has a single CXL memory expander with a 4GB of memory.
9
10Things to note:
11
12* Cross-Bridge interleave is not being used.
13* The expanders are in two separate but adjascent memory regions.
14* This CEDT/SRAT describes one node per device
15* The expanders have the same performance and will be in the same memory tier.
16
17:doc:`CEDT <../acpi/cedt>`::
18
19            Subtable Type : 00 [CXL Host Bridge Structure]
20                 Reserved : 00
21                   Length : 0020
22   Associated host bridge : 00000007
23    Specification version : 00000001
24                 Reserved : 00000000
25            Register base : 0000010370400000
26          Register length : 0000000000010000
27
28            Subtable Type : 00 [CXL Host Bridge Structure]
29                 Reserved : 00
30                   Length : 0020
31   Associated host bridge : 00000006
32    Specification version : 00000001
33                 Reserved : 00000000
34            Register base : 0000010380800000
35          Register length : 0000000000010000
36
37            Subtable Type : 01 [CXL Fixed Memory Window Structure]
38                 Reserved : 00
39                   Length : 002C
40                 Reserved : 00000000
41      Window base address : 0000001000000000
42              Window size : 0000000100000000
43 Interleave Members (2^n) : 00
44    Interleave Arithmetic : 00
45                 Reserved : 0000
46              Granularity : 00000000
47             Restrictions : 0006
48                    QtgId : 0001
49             First Target : 00000007
50
51            Subtable Type : 01 [CXL Fixed Memory Window Structure]
52                 Reserved : 00
53                   Length : 002C
54                 Reserved : 00000000
55      Window base address : 0000001100000000
56              Window size : 0000000100000000
57 Interleave Members (2^n) : 00
58    Interleave Arithmetic : 00
59                 Reserved : 0000
60              Granularity : 00000000
61             Restrictions : 0006
62                    QtgId : 0001
63             First Target : 00000006
64
65:doc:`SRAT <../acpi/srat>`::
66
67         Subtable Type : 01 [Memory Affinity]
68                Length : 28
69      Proximity Domain : 00000001
70             Reserved1 : 0000
71          Base Address : 0000001000000000
72        Address Length : 0000000100000000
73             Reserved2 : 00000000
74 Flags (decoded below) : 0000000B
75             Enabled : 1
76       Hot Pluggable : 1
77        Non-Volatile : 0
78
79         Subtable Type : 01 [Memory Affinity]
80                Length : 28
81      Proximity Domain : 00000002
82             Reserved1 : 0000
83          Base Address : 0000001100000000
84        Address Length : 0000000100000000
85             Reserved2 : 00000000
86 Flags (decoded below) : 0000000B
87             Enabled : 1
88       Hot Pluggable : 1
89        Non-Volatile : 0
90
91:doc:`HMAT <../acpi/hmat>`::
92
93               Structure Type : 0001 [SLLBI]
94                    Data Type : 00   [Latency]
95 Target Proximity Domain List : 00000000
96 Target Proximity Domain List : 00000001
97 Target Proximity Domain List : 00000002
98                        Entry : 0080
99                        Entry : 0100
100                        Entry : 0100
101
102               Structure Type : 0001 [SLLBI]
103                    Data Type : 03   [Bandwidth]
104 Target Proximity Domain List : 00000000
105 Target Proximity Domain List : 00000001
106 Target Proximity Domain List : 00000002
107                        Entry : 1200
108                        Entry : 0200
109                        Entry : 0200
110
111:doc:`SLIT <../acpi/slit>`::
112
113     Signature : "SLIT"    [System Locality Information Table]
114    Localities : 0000000000000003
115  Locality   0 : 10 20 20
116  Locality   1 : FF 0A FF
117  Locality   2 : FF FF 0A
118
119:doc:`DSDT <../acpi/dsdt>`::
120
121  Scope (_SB)
122  {
123    Device (S0D0)
124    {
125        Name (_HID, "ACPI0016" /* Compute Express Link Host Bridge */)  // _HID: Hardware ID
126        ...
127        Name (_UID, 0x07)  // _UID: Unique ID
128    }
129    ...
130    Device (S0D5)
131    {
132        Name (_HID, "ACPI0016" /* Compute Express Link Host Bridge */)  // _HID: Hardware ID
133        ...
134        Name (_UID, 0x06)  // _UID: Unique ID
135    }
136  }
137