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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /Documentation/devicetree/bindings/reserved-memory
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/devicetree/bindings/reserved-memory')
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/framebuffer.yaml52
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml46
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/memory-region.yaml40
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/nvidia,tegra210-emc-table.yaml31
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/nvidia,tegra264-bpmp-shmem.yaml47
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/phram.yaml47
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.yaml46
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/qcom,rmtfs-mem.yaml55
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/ramoops.yaml144
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt1
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml181
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml97
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/xen,shared-memory.txt24
13 files changed, 811 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/reserved-memory/framebuffer.yaml b/Documentation/devicetree/bindings/reserved-memory/framebuffer.yaml
new file mode 100644
index 0000000000..851ec24d61
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/framebuffer.yaml
@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/framebuffer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: /reserved-memory framebuffer node
+
+maintainers:
+ - devicetree-spec@vger.kernel.org
+
+allOf:
+ - $ref: reserved-memory.yaml
+
+properties:
+ compatible:
+ const: framebuffer
+ description: >
+ This indicates a region of memory meant to be used as a framebuffer for
+ a set of display devices. It can be used by an operating system to keep
+ the framebuffer from being overwritten and use it as the backing memory
+ for a display device (such as simple-framebuffer).
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ / {
+ compatible = "foo";
+ model = "foo";
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ chosen {
+ framebuffer {
+ compatible = "simple-framebuffer";
+ memory-region = <&fb>;
+ };
+ };
+
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+
+ fb: framebuffer@80000000 {
+ compatible = "framebuffer";
+ reg = <0x80000000 0x007e9000>;
+ };
+ };
+ };
+...
diff --git a/Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml b/Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml
new file mode 100644
index 0000000000..c591ec37d7
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/google,open-dice.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Open Profile for DICE
+
+description: |
+ This binding represents a reserved memory region containing data
+ generated by the Open Profile for DICE protocol.
+
+ See https://pigweed.googlesource.com/open-dice/
+
+maintainers:
+ - David Brazdil <dbrazdil@google.com>
+
+allOf:
+ - $ref: reserved-memory.yaml
+
+properties:
+ compatible:
+ const: google,open-dice
+
+ reg:
+ description: page-aligned region of memory containing DICE data
+
+required:
+ - compatible
+ - reg
+ - no-map
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ reserved-memory {
+ #address-cells = <2>;
+ #size-cells = <1>;
+
+ dice: dice@12340000 {
+ compatible = "google,open-dice";
+ reg = <0x00 0x12340000 0x2000>;
+ no-map;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/reserved-memory/memory-region.yaml b/Documentation/devicetree/bindings/reserved-memory/memory-region.yaml
new file mode 100644
index 0000000000..592f180e6b
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/memory-region.yaml
@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/memory-region.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Reserved Memory Region
+
+maintainers:
+ - devicetree-spec@vger.kernel.org
+
+description: |
+ Regions in the /reserved-memory node may be referenced by other device
+ nodes by adding a memory-region property to the device node.
+
+select: true
+
+properties:
+ memory-region:
+ $ref: /schemas/types.yaml#/definitions/phandle-array
+ description: >
+ Phandle to a /reserved-memory child node assigned to the device.
+
+ memory-region-names:
+ $ref: /schemas/types.yaml#/definitions/string-array
+ description: >
+ A list of names, one for each corresponding entry in the
+ memory-region property
+
+additionalProperties: true
+
+examples:
+ - |
+ fb0: video@12300000 {
+ /* ... */
+ reg = <0x12300000 0x1000>;
+ memory-region = <&display_reserved>;
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/reserved-memory/nvidia,tegra210-emc-table.yaml b/Documentation/devicetree/bindings/reserved-memory/nvidia,tegra210-emc-table.yaml
new file mode 100644
index 0000000000..e2ace3df94
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/nvidia,tegra210-emc-table.yaml
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/nvidia,tegra210-emc-table.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVIDIA Tegra210 EMC Frequency Table
+
+maintainers:
+ - Thierry Reding <thierry.reding@gmail.com>
+ - Jon Hunter <jonathanh@nvidia.com>
+
+description: On Tegra210, firmware passes a binary representation of the
+ EMC frequency table via a reserved memory region.
+
+allOf:
+ - $ref: reserved-memory.yaml
+
+properties:
+ compatible:
+ const: nvidia,tegra210-emc-table
+
+ reg:
+ description: region of memory reserved by firmware to pass the EMC
+ frequency table
+
+unevaluatedProperties: false
+
+required:
+ - compatible
+ - reg
diff --git a/Documentation/devicetree/bindings/reserved-memory/nvidia,tegra264-bpmp-shmem.yaml b/Documentation/devicetree/bindings/reserved-memory/nvidia,tegra264-bpmp-shmem.yaml
new file mode 100644
index 0000000000..f9b2f0fdc2
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/nvidia,tegra264-bpmp-shmem.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/nvidia,tegra264-bpmp-shmem.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Tegra CPU-NS - BPMP IPC reserved memory
+
+maintainers:
+ - Peter De Schrijver <pdeschrijver@nvidia.com>
+
+description: |
+ Define a memory region used for communication between CPU-NS and BPMP.
+ Typically this node is created by the bootloader as the physical address
+ has to be known to both CPU-NS and BPMP for correct IPC operation.
+ The memory region is defined using a child node under /reserved-memory.
+ The sub-node is named shmem@<address>.
+
+allOf:
+ - $ref: reserved-memory.yaml
+
+properties:
+ compatible:
+ const: nvidia,tegra264-bpmp-shmem
+
+ reg:
+ description: The physical address and size of the shared SDRAM region
+
+unevaluatedProperties: false
+
+required:
+ - compatible
+ - reg
+ - no-map
+
+examples:
+ - |
+ reserved-memory {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ dram_cpu_bpmp_mail: shmem@f1be0000 {
+ compatible = "nvidia,tegra264-bpmp-shmem";
+ reg = <0x0 0xf1be0000 0x0 0x2000>;
+ no-map;
+ };
+ };
+...
diff --git a/Documentation/devicetree/bindings/reserved-memory/phram.yaml b/Documentation/devicetree/bindings/reserved-memory/phram.yaml
new file mode 100644
index 0000000000..65c7cacf9b
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/phram.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/phram.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MTD/block device in RAM
+
+description: |
+ Specifies that the reserved memory region can be used as an MTD or block
+ device.
+
+ The "phram" node is named after the "MTD in PHysical RAM" driver which
+ provides an implementation of this functionality in Linux.
+
+maintainers:
+ - Vincent Whitchurch <vincent.whitchurch@axis.com>
+
+allOf:
+ - $ref: reserved-memory.yaml
+ - $ref: /schemas/mtd/mtd.yaml
+
+properties:
+ compatible:
+ const: phram
+
+ reg:
+ description: region of memory that can be used as an MTD/block device
+
+required:
+ - compatible
+ - reg
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ phram: flash@12340000 {
+ compatible = "phram";
+ label = "rootfs";
+ reg = <0x12340000 0x00800000>;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.yaml b/Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.yaml
new file mode 100644
index 0000000000..610f8ef37e
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.yaml
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/qcom,cmd-db.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Command DB
+
+description: |
+ Command DB is a database that provides a mapping between resource key and the
+ resource address for a system resource managed by a remote processor. The data
+ is stored in a shared memory region and is loaded by the remote processor.
+
+ Some of the Qualcomm Technologies Inc SoC's have hardware accelerators for
+ controlling shared resources. Depending on the board configuration the shared
+ resource properties may change. These properties are dynamically probed by the
+ remote processor and made available in the shared memory.
+
+maintainers:
+ - Bjorn Andersson <bjorn.andersson@linaro.org>
+
+allOf:
+ - $ref: reserved-memory.yaml
+
+properties:
+ compatible:
+ const: qcom,cmd-db
+
+required:
+ - reg
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+
+ reserved-memory@85fe0000 {
+ reg = <0x85fe0000 0x20000>;
+ compatible = "qcom,cmd-db";
+ no-map;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/reserved-memory/qcom,rmtfs-mem.yaml b/Documentation/devicetree/bindings/reserved-memory/qcom,rmtfs-mem.yaml
new file mode 100644
index 0000000000..bab982f004
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/qcom,rmtfs-mem.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/qcom,rmtfs-mem.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Remote File System Memory
+
+description: |
+ This binding describes the Qualcomm remote filesystem memory, which serves the
+ purpose of describing the shared memory region used for remote processors to
+ access block device data using the Remote Filesystem protocol.
+
+maintainers:
+ - Bjorn Andersson <bjorn.andersson@linaro.org>
+
+allOf:
+ - $ref: reserved-memory.yaml
+
+properties:
+ compatible:
+ const: qcom,rmtfs-mem
+
+ qcom,client-id:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: >
+ identifier of the client to use this region for buffers
+
+ qcom,vmid:
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ description: >
+ Array of vmids of the remote processors, to set up memory protection
+ minItems: 1
+ maxItems: 2
+
+required:
+ - qcom,client-id
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+
+ rmtfs@86700000 {
+ compatible = "qcom,rmtfs-mem";
+ reg = <0x86700000 0xe0000>;
+ no-map;
+
+ qcom,client-id = <1>;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/reserved-memory/ramoops.yaml b/Documentation/devicetree/bindings/reserved-memory/ramoops.yaml
new file mode 100644
index 0000000000..45cc39ecc9
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/ramoops.yaml
@@ -0,0 +1,144 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/ramoops.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ramoops oops/panic logger
+
+description: |
+ ramoops provides persistent RAM storage for oops and panics, so they can be
+ recovered after a reboot. This is a child-node of "/reserved-memory", and
+ is named "ramoops" after the backend, rather than "pstore" which is the
+ subsystem.
+
+ Parts of this storage may be set aside for other persistent log buffers, such
+ as kernel log messages, or for optional ECC error-correction data. The total
+ size of these optional buffers must fit in the reserved region.
+
+ Any remaining space will be used for a circular buffer of oops and panic
+ records. These records have a configurable size, with a size of 0 indicating
+ that they should be disabled.
+
+ At least one of "record-size", "console-size", "ftrace-size", or "pmsg-size"
+ must be set non-zero, but are otherwise optional as listed below.
+
+maintainers:
+ - Kees Cook <keescook@chromium.org>
+
+allOf:
+ - $ref: reserved-memory.yaml
+
+properties:
+ compatible:
+ const: ramoops
+
+ reg:
+ description: region of memory that is preserved between reboots
+
+ ecc-size:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: enables ECC support and specifies ECC buffer size in bytes
+ default: 0 # no ECC
+
+ record-size:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: maximum size in bytes of each kmsg dump
+ default: 0
+
+ console-size:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: size in bytes of log buffer reserved for kernel messages
+ default: 0
+
+ ftrace-size:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: size in bytes of log buffer reserved for function tracing and profiling
+ default: 0
+
+ pmsg-size:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: size in bytes of log buffer reserved for userspace messages
+ default: 0
+
+ mem-type:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: if present, sets the type of mapping is to be used to map the reserved region.
+ default: 0
+ oneOf:
+ - const: 0
+ description: write-combined
+ - const: 1
+ description: unbuffered
+ - const: 2
+ description: cached
+
+ max-reason:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ default: 2 # log oopses and panics
+ maximum: 0x7fffffff
+ description: |
+ If present, sets maximum type of kmsg dump reasons to store.
+ This can be set to INT_MAX to store all kmsg dumps.
+ See include/linux/kmsg_dump.h KMSG_DUMP_* for other kmsg dump reason values.
+ Setting this to 0 (KMSG_DUMP_UNDEF), means the reason filtering will be
+ controlled by the printk.always_kmsg_dump boot param.
+ If unset, it will be 2 (KMSG_DUMP_OOPS), otherwise 5 (KMSG_DUMP_MAX).
+
+ flags:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ default: 0
+ description: |
+ If present, pass ramoops behavioral flags
+ (see include/linux/pstore_ram.h RAMOOPS_FLAG_* for flag values).
+
+ no-dump-oops:
+ deprecated: true
+ type: boolean
+ description: |
+ Use max_reason instead. If present, and max_reason is not specified,
+ it is equivalent to max_reason = 1 (KMSG_DUMP_PANIC).
+
+ unbuffered:
+ deprecated: true
+ type: boolean
+ description: |
+ Use mem_type instead. If present, and mem_type is not specified,
+ it is equivalent to mem_type = 1 and uses unbuffered mappings to map
+ the reserved region (defaults to buffered mappings mem_type = 0).
+ If both are specified -- "mem_type" overrides "unbuffered".
+
+unevaluatedProperties: false
+
+required:
+ - compatible
+ - reg
+
+anyOf:
+ - required: [record-size]
+ - required: [console-size]
+ - required: [ftrace-size]
+ - required: [pmsg-size]
+
+examples:
+ - |
+ / {
+ compatible = "foo";
+ model = "foo";
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+
+ ramoops@bfdf0000 {
+ compatible = "ramoops";
+ reg = <0xbfdf0000 0x10000>; /* 64kB */
+ console-size = <0x8000>; /* 32kB */
+ record-size = <0x400>; /* 1kB */
+ ecc-size = <16>;
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
new file mode 100644
index 0000000000..1810701a85
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
@@ -0,0 +1 @@
+This file has been moved to reserved-memory.yaml.
diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml
new file mode 100644
index 0000000000..c680e397cf
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml
@@ -0,0 +1,181 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/reserved-memory.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: /reserved-memory Child Node Common
+
+maintainers:
+ - devicetree-spec@vger.kernel.org
+
+description: >
+ Reserved memory is specified as a node under the /reserved-memory node. The
+ operating system shall exclude reserved memory from normal usage one can
+ create child nodes describing particular reserved (excluded from normal use)
+ memory regions. Such memory regions are usually designed for the special
+ usage by various device drivers.
+
+ Each child of the reserved-memory node specifies one or more regions
+ of reserved memory. Each child node may either use a 'reg' property to
+ specify a specific range of reserved memory, or a 'size' property with
+ optional constraints to request a dynamically allocated block of
+ memory.
+
+ Following the generic-names recommended practice, node names should
+ reflect the purpose of the node (ie. "framebuffer" or "dma-pool").
+ Unit address (@<address>) should be appended to the name if the node
+ is a static allocation.
+
+properties:
+ reg: true
+
+ size:
+ oneOf:
+ - $ref: /schemas/types.yaml#/definitions/uint32
+ - $ref: /schemas/types.yaml#/definitions/uint64
+ description: >
+ Length based on parent's \#size-cells. Size in bytes of memory to
+ reserve.
+
+ alignment:
+ oneOf:
+ - $ref: /schemas/types.yaml#/definitions/uint32
+ - $ref: /schemas/types.yaml#/definitions/uint64
+ description: >
+ Length based on parent's \#size-cells. Address boundary for
+ alignment of allocation.
+
+ alloc-ranges:
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ description: >
+ Address and Length pairs. Specifies regions of memory that are
+ acceptable to allocate from.
+
+ iommu-addresses:
+ $ref: /schemas/types.yaml#/definitions/phandle-array
+ description: >
+ A list of phandle and specifier pairs that describe static IO virtual
+ address space mappings and carveouts associated with a given reserved
+ memory region. The phandle in the first cell refers to the device for
+ which the mapping or carveout is to be created.
+
+ The specifier consists of an address/size pair and denotes the IO
+ virtual address range of the region for the given device. The exact
+ format depends on the values of the "#address-cells" and "#size-cells"
+ properties of the device referenced via the phandle.
+
+ When used in combination with a "reg" property, an IOVA mapping is to
+ be established for this memory region. One example where this can be
+ useful is to create an identity mapping for physical memory that the
+ firmware has configured some hardware to access (such as a bootsplash
+ framebuffer).
+
+ If no "reg" property is specified, the "iommu-addresses" property
+ defines carveout regions in the IOVA space for the given device. This
+ can be useful if a certain memory region should not be mapped through
+ the IOMMU.
+
+ no-map:
+ type: boolean
+ description: >
+ Indicates the operating system must not create a virtual mapping
+ of the region as part of its standard mapping of system memory,
+ nor permit speculative access to it under any circumstances other
+ than under the control of the device driver using the region.
+
+ reusable:
+ type: boolean
+ description: >
+ The operating system can use the memory in this region with the
+ limitation that the device driver(s) owning the region need to be
+ able to reclaim it back. Typically that means that the operating
+ system can use that region to store volatile or cached data that
+ can be otherwise regenerated or migrated elsewhere.
+
+allOf:
+ - if:
+ required:
+ - no-map
+
+ then:
+ not:
+ required:
+ - reusable
+
+ - if:
+ required:
+ - reusable
+
+ then:
+ not:
+ required:
+ - no-map
+
+oneOf:
+ - oneOf:
+ - required:
+ - reg
+
+ - required:
+ - size
+
+ - oneOf:
+ # IOMMU reservations
+ - required:
+ - iommu-addresses
+
+ # IOMMU mappings
+ - required:
+ - reg
+ - iommu-addresses
+
+additionalProperties: true
+
+examples:
+ - |
+ / {
+ compatible = "foo";
+ model = "foo";
+
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ reserved-memory {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ ranges;
+
+ adsp_resv: reservation-adsp {
+ /*
+ * Restrict IOVA mappings for ADSP buffers to the 512 MiB region
+ * from 0x40000000 - 0x5fffffff. Anything outside is reserved by
+ * the ADSP for I/O memory and private memory allocations.
+ */
+ iommu-addresses = <&adsp 0x0 0x00000000 0x00 0x40000000>,
+ <&adsp 0x0 0x60000000 0xff 0xa0000000>;
+ };
+
+ fb: framebuffer@90000000 {
+ reg = <0x0 0x90000000 0x0 0x00800000>;
+ iommu-addresses = <&dc0 0x0 0x90000000 0x0 0x00800000>;
+ };
+ };
+
+ bus@0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0x0 0x0 0x0 0x40000000>;
+
+ adsp: adsp@2990000 {
+ reg = <0x2990000 0x2000>;
+ memory-region = <&adsp_resv>;
+ };
+
+ dc0: display@15200000 {
+ reg = <0x15200000 0x10000>;
+ memory-region = <&fb>;
+ };
+ };
+ };
+...
diff --git a/Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml b/Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml
new file mode 100644
index 0000000000..457de0920c
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml
@@ -0,0 +1,97 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/shared-dma-pool.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: /reserved-memory DMA pool
+
+maintainers:
+ - devicetree-spec@vger.kernel.org
+
+allOf:
+ - $ref: reserved-memory.yaml
+
+properties:
+ compatible:
+ oneOf:
+ - const: shared-dma-pool
+ description: >
+ This indicates a region of memory meant to be used as a shared
+ pool of DMA buffers for a set of devices. It can be used by an
+ operating system to instantiate the necessary pool management
+ subsystem if necessary.
+
+ - const: restricted-dma-pool
+ description: >
+ This indicates a region of memory meant to be used as a pool
+ of restricted DMA buffers for a set of devices. The memory
+ region would be the only region accessible to those devices.
+ When using this, the no-map and reusable properties must not
+ be set, so the operating system can create a virtual mapping
+ that will be used for synchronization. The main purpose for
+ restricted DMA is to mitigate the lack of DMA access control
+ on systems without an IOMMU, which could result in the DMA
+ accessing the system memory at unexpected times and/or
+ unexpected addresses, possibly leading to data leakage or
+ corruption. The feature on its own provides a basic level of
+ protection against the DMA overwriting buffer contents at
+ unexpected times. However, to protect against general data
+ leakage and system memory corruption, the system needs to
+ provide way to lock down the memory access, e.g., MPU. Note
+ that since coherent allocation needs remapping, one must set
+ up another device coherent pool by shared-dma-pool and use
+ dma_alloc_from_dev_coherent instead for atomic coherent
+ allocation.
+
+ linux,cma-default:
+ type: boolean
+ description: >
+ If this property is present, then Linux will use the region for
+ the default pool of the contiguous memory allocator.
+
+ linux,dma-default:
+ type: boolean
+ description: >
+ If this property is present, then Linux will use the region for
+ the default pool of the consistent DMA allocator.
+
+if:
+ properties:
+ compatible:
+ contains:
+ const: restricted-dma-pool
+then:
+ properties:
+ no-map: false
+ reusable: false
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+
+ /* global autoconfigured region for contiguous allocations */
+ linux,cma {
+ compatible = "shared-dma-pool";
+ reusable;
+ size = <0x4000000>;
+ alignment = <0x2000>;
+ linux,cma-default;
+ };
+
+ display_reserved: framebuffer@78000000 {
+ reg = <0x78000000 0x800000>;
+ };
+
+ restricted_dma_reserved: restricted-dma-pool@50000000 {
+ compatible = "restricted-dma-pool";
+ reg = <0x50000000 0x4000000>;
+ };
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/reserved-memory/xen,shared-memory.txt b/Documentation/devicetree/bindings/reserved-memory/xen,shared-memory.txt
new file mode 100644
index 0000000000..d483a2103d
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/xen,shared-memory.txt
@@ -0,0 +1,24 @@
+* Xen hypervisor reserved-memory binding
+
+Expose one or more memory regions as reserved-memory to the guest
+virtual machine. Typically, a region is configured at VM creation time
+to be a shared memory area across multiple virtual machines for
+communication among them.
+
+For each of these pre-shared memory regions, a range is exposed under
+the /reserved-memory node as a child node. Each range sub-node is named
+xen-shmem@<address> and has the following properties:
+
+- compatible:
+ compatible = "xen,shared-memory-v1"
+
+- reg:
+ the base guest physical address and size of the shared memory region
+
+- xen,offset: (borrower VMs only)
+ 64 bit integer offset within the owner virtual machine's shared
+ memory region used for the mapping in the borrower VM.
+
+- xen,id:
+ a string that identifies the shared memory region as specified in
+ the VM config file