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Diffstat (limited to 'Documentation/devicetree/bindings/reserved-memory')
5 files changed, 313 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.txt b/Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.txt new file mode 100644 index 000000000..68395530c --- /dev/null +++ b/Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.txt @@ -0,0 +1,37 @@ +Command DB +--------- + +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. + +The bindings for Command DB is specified in the reserved-memory section in +devicetree. The devicetree representation of the command DB driver should be: + +Properties: +- compatible: + Usage: required + Value type: <string> + Definition: Should be "qcom,cmd-db" + +- reg: + Usage: required + Value type: <prop encoded array> + Definition: The register address that points to the actual location of + the Command DB in memory. + +Example: + + reserved-memory { + [...] + reserved-memory@85fe0000 { + reg = <0x0 0x85fe0000 0x0 0x20000>; + compatible = "qcom,cmd-db"; + no-map; + }; + }; diff --git a/Documentation/devicetree/bindings/reserved-memory/qcom,rmtfs-mem.txt b/Documentation/devicetree/bindings/reserved-memory/qcom,rmtfs-mem.txt new file mode 100644 index 000000000..8562ba1dc --- /dev/null +++ b/Documentation/devicetree/bindings/reserved-memory/qcom,rmtfs-mem.txt @@ -0,0 +1,51 @@ +Qualcomm Remote File System Memory binding + +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. + +- compatible: + Usage: required + Value type: <stringlist> + Definition: must be: + "qcom,rmtfs-mem" + +- reg: + Usage: required for static allocation + Value type: <prop-encoded-array> + Definition: must specify base address and size of the memory region, + as described in reserved-memory.txt + +- size: + Usage: required for dynamic allocation + Value type: <prop-encoded-array> + Definition: must specify a size of the memory region, as described in + reserved-memory.txt + +- qcom,client-id: + Usage: required + Value type: <u32> + Definition: identifier of the client to use this region for buffers. + +- qcom,vmid: + Usage: optional + Value type: <u32> + Definition: vmid of the remote processor, to set up memory protection. + += EXAMPLE +The following example shows the remote filesystem memory setup for APQ8016, +with the rmtfs region for the Hexagon DSP (id #1) located at 0x86700000. + + reserved-memory { + #address-cells = <2>; + #size-cells = <2>; + ranges; + + rmtfs@86700000 { + compatible = "qcom,rmtfs-mem"; + reg = <0x0 0x86700000 0x0 0xe0000>; + no-map; + + qcom,client-id = <1>; + }; + }; diff --git a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt new file mode 100644 index 000000000..b7886fea3 --- /dev/null +++ b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt @@ -0,0 +1,60 @@ +Ramoops oops/panic logger +========================= + +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. + + +Required properties: + +- compatible: must be "ramoops" + +- reg: region of memory that is preserved between reboots + + +Optional properties: + +- ecc-size: enables ECC support and specifies ECC buffer size in bytes + (defaults to 0: no ECC) + +- record-size: maximum size in bytes of each kmsg dump. + (defaults to 0: disabled) + +- console-size: size in bytes of log buffer reserved for kernel messages + (defaults to 0: disabled) + +- ftrace-size: size in bytes of log buffer reserved for function tracing and + profiling (defaults to 0: disabled) + +- pmsg-size: size in bytes of log buffer reserved for userspace messages + (defaults to 0: disabled) + +- unbuffered: if present, use unbuffered mappings to map the reserved region + (defaults to buffered mappings) + +- max-reason: if present, sets maximum type of kmsg dump reasons to store + (defaults to 2: log Oopses and Panics). 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 KMSG_DUMP_OOPS, otherwise KMSG_DUMP_MAX. + +- no-dump-oops: deprecated, use max_reason instead. If present, and + max_reason is not specified, it is equivalent to max_reason = 1 + (KMSG_DUMP_PANIC). + +- flags: if present, pass ramoops behavioral flags (defaults to 0, + see include/linux/pstore_ram.h RAMOOPS_FLAG_* for flag values). 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 000000000..e8d3096d9 --- /dev/null +++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt @@ -0,0 +1,141 @@ +*** Reserved memory regions *** + +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. + +Parameters for each memory region can be encoded into the device tree +with the following nodes: + +/reserved-memory node +--------------------- +#address-cells, #size-cells (required) - standard definition + - Should use the same values as the root node +ranges (required) - standard definition + - Should be empty + +/reserved-memory/ child nodes +----------------------------- +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: +Requires either a) or b) below. +a) static allocation + reg (required) - standard definition +b) dynamic allocation + size (required) - length based on parent's #size-cells + - Size in bytes of memory to reserve. + alignment (optional) - length based on parent's #size-cells + - Address boundary for alignment of allocation. + alloc-ranges (optional) - prop-encoded-array (address, length pairs). + - Specifies regions of memory that are + acceptable to allocate from. + +If both reg and size are present, then the reg property takes precedence +and size is ignored. + +Additional properties: +compatible (optional) - standard definition + - may contain the following strings: + - shared-dma-pool: 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. + - vendor specific string in the form <vendor>,[<device>-]<usage> +no-map (optional) - empty property + - 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 (optional) - empty property + - 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. + +A node must not carry both the no-map and the reusable property as these are +logically contradictory. + +Linux implementation note: +- If a "linux,cma-default" property is present, then Linux will use the + region for the default pool of the contiguous memory allocator. + +- If a "linux,dma-default" property is present, then Linux will use the + region for the default pool of the consistent DMA allocator. + +Device node references to reserved memory +----------------------------------------- +Regions in the /reserved-memory node may be referenced by other device +nodes by adding a memory-region property to the device node. + +memory-region (optional) - phandle, specifier pairs to children of /reserved-memory +memory-region-names (optional) - a list of names, one for each corresponding + entry in the memory-region property + +Example +------- +This example defines 3 contiguous regions are defined for Linux kernel: +one default of all device drivers (named linux,cma@72000000 and 64MiB in size), +one dedicated to the framebuffer device (named framebuffer@78000000, 8MiB), and +one for multimedia processing (named multimedia-memory@77000000, 64MiB). + +/ { + #address-cells = <1>; + #size-cells = <1>; + + memory { + reg = <0x40000000 0x40000000>; + }; + + 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>; + }; + + multimedia_reserved: multimedia@77000000 { + compatible = "acme,multimedia-memory"; + reg = <0x77000000 0x4000000>; + }; + }; + + /* ... */ + + fb0: video@12300000 { + memory-region = <&display_reserved>; + /* ... */ + }; + + scaler: scaler@12500000 { + memory-region = <&multimedia_reserved>; + /* ... */ + }; + + codec: codec@12600000 { + memory-region = <&multimedia_reserved>; + /* ... */ + }; +}; 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 000000000..d483a2103 --- /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 |