[PATCH v2 7/8] dt-bindings: reserved-memory: Add Arm FF-A lend pool

[Vincent Donnefort <vdonnefort@google.com>]

Add bindings for the "arm,ffa-lend-pool" reserved-memory CMA pool.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
---
 .../reserved-memory/arm,ffa-lend-pool.yaml    | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reserved-memory/arm,ffa-lend-pool.yaml

diff --git a/Documentation/devicetree/bindings/reserved-memory/arm,ffa-lend-pool.yaml b/Documentation/devicetree/bindings/reserved-memory/arm,ffa-lend-pool.yaml
new file mode 100644
index 000000000000..c02d36e1e418
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/arm,ffa-lend-pool.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/arm,ffa-lend-pool.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arm FF-A Memory Lend Pool
+
+maintainers:
+  - Vincent Donnefort <vdonnefort@google.com>
+
+description: |
+  When memory is lent to the Secure world via FF-A, CPU speculative accesses
+  from Non-Secure to the lent pages can still occur as long as it retains a
+  cacheable mapping to it.
+
+  Ideally, lent memory would be "no-map", but that would mean giving up MiBs of
+  useful memory. Instead, "arm,ffa-lend-pool" defines a reserved-memory CMA pool
+  to manage unmapping pages prior to lending and restoring them when reclaimed.
+
+allOf:
+  - $ref: reserved-memory.yaml
+
+properties:
+  compatible:
+    const: arm,ffa-lend-pool
+
+  no-map: false
+
+required:
+  - compatible
+  - reusable
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    / {
+        compatible = "foo";
+        model = "foo";
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        reserved-memory {
+            #address-cells = <2>;
+            #size-cells = <2>;
+            ranges;
+
+            ffa_lend: ffa-lend-pool {
+                compatible = "arm,ffa-lend-pool";
+                reusable;
+                size = <0x0 0x4000000>;
+            };
+        };
+    };
-- 
2.55.0.1082.g2b9226bbc0-goog