cxl: docs/platform/example-configs documentation

Add example ACPI Table configurations for different sample platforms.

Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20250512162134.3596150-7-gourry@gourry.net
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

6 files changed, 643 insertions, 0 deletions

diff --git a/Documentation/driver-api/cxl/index.rst b/Documentation/driver-api/cxl/index.rst
index 336322dc35a0a..6a5fb7e00c523 100644
--- a/Documentation/driver-api/cxl/index.rst
+++ b/Documentation/driver-api/cxl/index.rst
@@ -27,6 +27,7 @@ that have impacts on each other.  The docs here break up configurations steps.
 
    platform/bios-and-efi
    platform/acpi
+   platform/example-configs
 
 .. toctree::
    :maxdepth: 1
diff --git a/Documentation/driver-api/cxl/platform/example-configs.rst b/Documentation/driver-api/cxl/platform/example-configs.rst
new file mode 100644
index 0000000000000..90a10d7473c66
--- /dev/null
+++ b/Documentation/driver-api/cxl/platform/example-configs.rst
@@ -0,0 +1,13 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Example Platform Configurations
+###############################
+
+.. toctree::
+   :maxdepth: 1
+   :caption: Contents
+
+   example-configurations/one-dev-per-hb.rst
+   example-configurations/multi-dev-per-hb.rst
+   example-configurations/hb-interleave.rst
+   example-configurations/flexible.rst
diff --git a/Documentation/driver-api/cxl/platform/example-configurations/flexible.rst b/Documentation/driver-api/cxl/platform/example-configurations/flexible.rst
new file mode 100644
index 0000000000000..e39daba65fa0a
--- /dev/null
+++ b/Documentation/driver-api/cxl/platform/example-configurations/flexible.rst
@@ -0,0 +1,296 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================
+Flexible Presentation
+=====================
+This system has a single socket with two CXL host bridges. Each host bridge
+has two CXL memory expanders with a 4GB of memory (32GB total).
+
+On this system, the platform designer wanted to provide the user flexibility
+to configure the memory devices in various interleave or NUMA node
+configurations.  So they provided every combination.
+
+Things to note:
+
+* Cross-Bridge interleave is described in one CFMWS that covers all capacity.
+* One CFMWS is also described per-host bridge.
+* One CFMWS is also described per-device.
+* This SRAT describes one node for each of the above CFMWS.
+* The HMAT describes performance for each node in the SRAT.
+
+CEDT ::
+
+            Subtable Type : 00 [CXL Host Bridge Structure]
+                 Reserved : 00
+                   Length : 0020
+   Associated host bridge : 00000007
+    Specification version : 00000001
+                 Reserved : 00000000
+            Register base : 0000010370400000
+          Register length : 0000000000010000
+
+            Subtable Type : 00 [CXL Host Bridge Structure]
+                 Reserved : 00
+                   Length : 0020
+   Associated host bridge : 00000006
+    Specification version : 00000001
+                 Reserved : 00000000
+            Register base : 0000010380800000
+          Register length : 0000000000010000
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000001000000000
+              Window size : 0000000400000000
+ Interleave Members (2^n) : 01
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000007
+            Second Target : 00000006
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000002000000000
+              Window size : 0000000200000000
+ Interleave Members (2^n) : 00
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000007
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000002200000000
+              Window size : 0000000200000000
+ Interleave Members (2^n) : 00
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000006
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000003000000000
+              Window size : 0000000100000000
+ Interleave Members (2^n) : 00
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000007
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000003100000000
+              Window size : 0000000100000000
+ Interleave Members (2^n) : 00
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000007
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000003200000000
+              Window size : 0000000100000000
+ Interleave Members (2^n) : 00
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000006
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000003300000000
+              Window size : 0000000100000000
+ Interleave Members (2^n) : 00
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000006
+
+SRAT ::
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000001
+             Reserved1 : 0000
+          Base Address : 0000001000000000
+        Address Length : 0000000400000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000002
+             Reserved1 : 0000
+          Base Address : 0000002000000000
+        Address Length : 0000000200000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000003
+             Reserved1 : 0000
+          Base Address : 0000002200000000
+        Address Length : 0000000200000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000004
+             Reserved1 : 0000
+          Base Address : 0000003000000000
+        Address Length : 0000000100000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000005
+             Reserved1 : 0000
+          Base Address : 0000003100000000
+        Address Length : 0000000100000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000006
+             Reserved1 : 0000
+          Base Address : 0000003200000000
+        Address Length : 0000000100000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000007
+             Reserved1 : 0000
+          Base Address : 0000003300000000
+        Address Length : 0000000100000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+HMAT ::
+
+               Structure Type : 0001 [SLLBI]
+                    Data Type : 00   [Latency]
+ Target Proximity Domain List : 00000000
+ Target Proximity Domain List : 00000001
+ Target Proximity Domain List : 00000002
+ Target Proximity Domain List : 00000003
+ Target Proximity Domain List : 00000004
+ Target Proximity Domain List : 00000005
+ Target Proximity Domain List : 00000006
+ Target Proximity Domain List : 00000007
+                        Entry : 0080
+                        Entry : 0100
+                        Entry : 0100
+                        Entry : 0100
+                        Entry : 0100
+                        Entry : 0100
+                        Entry : 0100
+                        Entry : 0100
+
+               Structure Type : 0001 [SLLBI]
+                    Data Type : 03   [Bandwidth]
+ Target Proximity Domain List : 00000000
+ Target Proximity Domain List : 00000001
+ Target Proximity Domain List : 00000002
+ Target Proximity Domain List : 00000003
+ Target Proximity Domain List : 00000004
+ Target Proximity Domain List : 00000005
+ Target Proximity Domain List : 00000006
+ Target Proximity Domain List : 00000007
+                        Entry : 1200
+                        Entry : 0400
+                        Entry : 0200
+                        Entry : 0200
+                        Entry : 0100
+                        Entry : 0100
+                        Entry : 0100
+                        Entry : 0100
+
+SLIT ::
+
+     Signature : "SLIT"    [System Locality Information Table]
+    Localities : 0000000000000003
+  Locality   0 : 10 20 20 20 20 20 20 20
+  Locality   1 : FF 0A FF FF FF FF FF FF
+  Locality   2 : FF FF 0A FF FF FF FF FF
+  Locality   3 : FF FF FF 0A FF FF FF FF
+  Locality   4 : FF FF FF FF 0A FF FF FF
+  Locality   5 : FF FF FF FF FF 0A FF FF
+  Locality   6 : FF FF FF FF FF FF 0A FF
+  Locality   7 : FF FF FF FF FF FF FF 0A
+
+DSDT ::
+
+  Scope (_SB)
+  {
+    Device (S0D0)
+    {
+        Name (_HID, "ACPI0016" /* Compute Express Link Host Bridge */)  // _HID: Hardware ID
+        ...
+        Name (_UID, 0x07)  // _UID: Unique ID
+    }
+    ...
+    Device (S0D5)
+    {
+        Name (_HID, "ACPI0016" /* Compute Express Link Host Bridge */)  // _HID: Hardware ID
+        ...
+        Name (_UID, 0x06)  // _UID: Unique ID
+    }
+  }
diff --git a/Documentation/driver-api/cxl/platform/example-configurations/hb-interleave.rst b/Documentation/driver-api/cxl/platform/example-configurations/hb-interleave.rst
new file mode 100644
index 0000000000000..ce07e6162f261
--- /dev/null
+++ b/Documentation/driver-api/cxl/platform/example-configurations/hb-interleave.rst
@@ -0,0 +1,107 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================
+Cross-Host-Bridge Interleave
+============================
+This system has a single socket with two CXL host bridges. Each host bridge
+has a single CXL memory expander with a 4GB of memory.
+
+Things to note:
+
+* Cross-Bridge interleave is described.
+* The expanders are described by a single CFMWS.
+* This SRAT describes one node for both host bridges.
+* The HMAT describes a single node's performance.
+
+CEDT ::
+
+            Subtable Type : 00 [CXL Host Bridge Structure]
+                 Reserved : 00
+                   Length : 0020
+   Associated host bridge : 00000007
+    Specification version : 00000001
+                 Reserved : 00000000
+            Register base : 0000010370400000
+          Register length : 0000000000010000
+
+            Subtable Type : 00 [CXL Host Bridge Structure]
+                 Reserved : 00
+                   Length : 0020
+   Associated host bridge : 00000006
+    Specification version : 00000001
+                 Reserved : 00000000
+            Register base : 0000010380800000
+          Register length : 0000000000010000
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000001000000000
+              Window size : 0000000200000000
+ Interleave Members (2^n) : 01
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000007
+            Second Target : 00000006
+
+SRAT ::
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000001
+             Reserved1 : 0000
+          Base Address : 0000001000000000
+        Address Length : 0000000200000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+HMAT ::
+
+               Structure Type : 0001 [SLLBI]
+                    Data Type : 00   [Latency]
+ Target Proximity Domain List : 00000000
+ Target Proximity Domain List : 00000001
+ Target Proximity Domain List : 00000002
+                        Entry : 0080
+                        Entry : 0100
+
+               Structure Type : 0001 [SLLBI]
+                    Data Type : 03   [Bandwidth]
+ Target Proximity Domain List : 00000000
+ Target Proximity Domain List : 00000001
+ Target Proximity Domain List : 00000002
+                        Entry : 1200
+                        Entry : 0400
+
+SLIT ::
+
+     Signature : "SLIT"    [System Locality Information Table]
+    Localities : 0000000000000003
+  Locality   0 : 10 20
+  Locality   1 : FF 0A
+
+DSDT ::
+
+  Scope (_SB)
+  {
+    Device (S0D0)
+    {
+        Name (_HID, "ACPI0016" /* Compute Express Link Host Bridge */)  // _HID: Hardware ID
+        ...
+        Name (_UID, 0x07)  // _UID: Unique ID
+    }
+    ...
+    Device (S0D5)
+    {
+        Name (_HID, "ACPI0016" /* Compute Express Link Host Bridge */)  // _HID: Hardware ID
+        ...
+        Name (_UID, 0x06)  // _UID: Unique ID
+    }
+  }
diff --git a/Documentation/driver-api/cxl/platform/example-configurations/multi-dev-per-hb.rst b/Documentation/driver-api/cxl/platform/example-configurations/multi-dev-per-hb.rst
new file mode 100644
index 0000000000000..6adf7c639490a
--- /dev/null
+++ b/Documentation/driver-api/cxl/platform/example-configurations/multi-dev-per-hb.rst
@@ -0,0 +1,90 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+================================
+Multiple Devices per Host Bridge
+================================
+
+In this example system we will have a single socket and one CXL host bridge.
+There are two CXL memory expanders with 4GB attached to the host bridge.
+
+Things to note:
+
+* Intra-Bridge interleave is not described here.
+* The expanders are described by a single CEDT/CFMWS.
+* This CEDT/SRAT describes one node for both devices.
+* There is only one proximity domain the HMAT for both devices.
+
+CEDT ::
+
+            Subtable Type : 00 [CXL Host Bridge Structure]
+                 Reserved : 00
+                   Length : 0020
+   Associated host bridge : 00000007
+    Specification version : 00000001
+                 Reserved : 00000000
+            Register base : 0000010370400000
+          Register length : 0000000000010000
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000001000000000
+              Window size : 0000000200000000
+ Interleave Members (2^n) : 00
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000007
+
+SRAT ::
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000001
+             Reserved1 : 0000
+          Base Address : 0000001000000000
+        Address Length : 0000000200000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+HMAT ::
+
+               Structure Type : 0001 [SLLBI]
+                    Data Type : 00   [Latency]
+ Target Proximity Domain List : 00000000
+ Target Proximity Domain List : 00000001
+                        Entry : 0080
+                        Entry : 0100
+
+               Structure Type : 0001 [SLLBI]
+                    Data Type : 03   [Bandwidth]
+ Target Proximity Domain List : 00000000
+ Target Proximity Domain List : 00000001
+                        Entry : 1200
+                        Entry : 0200
+
+SLIT ::
+
+     Signature : "SLIT"    [System Locality Information Table]
+    Localities : 0000000000000003
+  Locality   0 : 10 20
+  Locality   1 : FF 0A
+
+DSDT ::
+
+  Scope (_SB)
+  {
+    Device (S0D0)
+    {
+        Name (_HID, "ACPI0016" /* Compute Express Link Host Bridge */)  // _HID: Hardware ID
+        ...
+        Name (_UID, 0x07)  // _UID: Unique ID
+    }
+    ...
+  }
diff --git a/Documentation/driver-api/cxl/platform/example-configurations/one-dev-per-hb.rst b/Documentation/driver-api/cxl/platform/example-configurations/one-dev-per-hb.rst
new file mode 100644
index 0000000000000..b89ba3cab98fc
--- /dev/null
+++ b/Documentation/driver-api/cxl/platform/example-configurations/one-dev-per-hb.rst
@@ -0,0 +1,136 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+One Device per Host Bridge
+==========================
+
+This system has a single socket with two CXL host bridges. Each host bridge
+has a single CXL memory expander with a 4GB of memory.
+
+Things to note:
+
+* Cross-Bridge interleave is not being used.
+* The expanders are in two separate but adjascent memory regions.
+* This CEDT/SRAT describes one node per device
+* The expanders have the same performance and will be in the same memory tier.
+
+CEDT ::
+
+            Subtable Type : 00 [CXL Host Bridge Structure]
+                 Reserved : 00
+                   Length : 0020
+   Associated host bridge : 00000007
+    Specification version : 00000001
+                 Reserved : 00000000
+            Register base : 0000010370400000
+          Register length : 0000000000010000
+
+            Subtable Type : 00 [CXL Host Bridge Structure]
+                 Reserved : 00
+                   Length : 0020
+   Associated host bridge : 00000006
+    Specification version : 00000001
+                 Reserved : 00000000
+            Register base : 0000010380800000
+          Register length : 0000000000010000
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000001000000000
+              Window size : 0000000100000000
+ Interleave Members (2^n) : 00
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000007
+
+            Subtable Type : 01 [CXL Fixed Memory Window Structure]
+                 Reserved : 00
+                   Length : 002C
+                 Reserved : 00000000
+      Window base address : 0000001100000000
+              Window size : 0000000100000000
+ Interleave Members (2^n) : 00
+    Interleave Arithmetic : 00
+                 Reserved : 0000
+              Granularity : 00000000
+             Restrictions : 0006
+                    QtgId : 0001
+             First Target : 00000006
+
+SRAT ::
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000001
+             Reserved1 : 0000
+          Base Address : 0000001000000000
+        Address Length : 0000000100000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+         Subtable Type : 01 [Memory Affinity]
+                Length : 28
+      Proximity Domain : 00000002
+             Reserved1 : 0000
+          Base Address : 0000001100000000
+        Address Length : 0000000100000000
+             Reserved2 : 00000000
+ Flags (decoded below) : 0000000B
+             Enabled : 1
+       Hot Pluggable : 1
+        Non-Volatile : 0
+
+HMAT ::
+
+               Structure Type : 0001 [SLLBI]
+                    Data Type : 00   [Latency]
+ Target Proximity Domain List : 00000000
+ Target Proximity Domain List : 00000001
+ Target Proximity Domain List : 00000002
+                        Entry : 0080
+                        Entry : 0100
+                        Entry : 0100
+
+               Structure Type : 0001 [SLLBI]
+                    Data Type : 03   [Bandwidth]
+ Target Proximity Domain List : 00000000
+ Target Proximity Domain List : 00000001
+ Target Proximity Domain List : 00000002
+                        Entry : 1200
+                        Entry : 0200
+                        Entry : 0200
+
+SLIT ::
+
+     Signature : "SLIT"    [System Locality Information Table]
+    Localities : 0000000000000003
+  Locality   0 : 10 20 20
+  Locality   1 : FF 0A FF
+  Locality   2 : FF FF 0A
+
+DSDT ::
+
+  Scope (_SB)
+  {
+    Device (S0D0)
+    {
+        Name (_HID, "ACPI0016" /* Compute Express Link Host Bridge */)  // _HID: Hardware ID
+        ...
+        Name (_UID, 0x07)  // _UID: Unique ID
+    }
+    ...
+    Device (S0D5)
+    {
+        Name (_HID, "ACPI0016" /* Compute Express Link Host Bridge */)  // _HID: Hardware ID
+        ...
+        Name (_UID, 0x06)  // _UID: Unique ID
+    }
+  }