From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx> We introduced KHO into Linux: A framework that allows Linux to pass metadata and memory across kexec from Linux to Linux. KHO reuses fdt as file format and shares a lot of the same properties of firmware-to- Linux boot formats: It needs a stable, documented ABI that allows for forward and backward compatibility as well as versioning. As first user of KHO, we introduced memblock which can now preserve memory ranges reserved with reserve_mem command line options contents across kexec, so you can use the post-kexec kernel to read traces from the pre-kexec kernel. This patch adds memblock schemas similar to "device" device tree ones to a new kho bindings directory. This allows us to force contributors to document the data that moves across KHO kexecs and catch breaking change during review. Co-developed-by: Alexander Graf <graf@xxxxxxxxxx> Signed-off-by: Alexander Graf <graf@xxxxxxxxxx> Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx> --- .../kho/bindings/memblock/reserve_mem.yaml | 41 ++++++++++++++++++ .../bindings/memblock/reserve_mem_map.yaml | 42 +++++++++++++++++++ 2 files changed, 83 insertions(+) create mode 100644 Documentation/kho/bindings/memblock/reserve_mem.yaml create mode 100644 Documentation/kho/bindings/memblock/reserve_mem_map.yaml diff --git a/Documentation/kho/bindings/memblock/reserve_mem.yaml b/Documentation/kho/bindings/memblock/reserve_mem.yaml new file mode 100644 index 000000000000..7b01791b10b3 --- /dev/null +++ b/Documentation/kho/bindings/memblock/reserve_mem.yaml @@ -0,0 +1,41 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/memblock/reserve_mem.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Memblock reserved memory + +maintainers: + - Mike Rapoport <rppt@xxxxxxxxxx> + +description: | + Memblock can serialize its current memory reservations created with + reserve_mem command line option across kexec through KHO. + The post-KHO kernel can then consume these reservations and they are + guaranteed to have the same physical address. + +properties: + compatible: + enum: + - reserve_mem-v1 + +patternProperties: + "$[0-9a-f_]+^": + $ref: reserve_mem_map.yaml# + description: reserved memory regions + +required: + - compatible + +additionalProperties: false + +examples: + - | + reserve_mem { + compatible = "reserve_mem-v1"; + r1 { + compatible = "reserve_mem_map-v1"; + mem = <0xc07c 0x2000000 0x01 0x00>; + }; + }; diff --git a/Documentation/kho/bindings/memblock/reserve_mem_map.yaml b/Documentation/kho/bindings/memblock/reserve_mem_map.yaml new file mode 100644 index 000000000000..09001c5f2124 --- /dev/null +++ b/Documentation/kho/bindings/memblock/reserve_mem_map.yaml @@ -0,0 +1,42 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/memblock/reserve_mem_map.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Memblock reserved memory regions + +maintainers: + - Mike Rapoport <rppt@xxxxxxxxxx> + +description: | + Memblock can serialize its current memory reservations created with + reserve_mem command line option across kexec through KHO. + This object describes each such region. + +properties: + compatible: + enum: + - reserve_mem_map-v1 + + mem: + $ref: /schemas/types.yaml#/definitions/uint32-array + description: | + Array of { u64 phys_addr, u64 len } elements that describe a list of + memory ranges. + +required: + - compatible + - mem + +additionalProperties: false + +examples: + - | + reserve_mem { + compatible = "reserve_mem-v1"; + r1 { + compatible = "reserve_mem_map-v1"; + mem = <0xc07c 0x2000000 0x01 0x00>; + }; + }; -- 2.47.2
