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- * ARM L2 Cache Controller
- ARM cores often have a separate level 2 cache controller. There are various
- implementations of the L2 cache controller with compatible programming models.
- The ARM L2 cache representation in the device tree should be done as follows:
- Required properties:
- - compatible : should be one of:
- "arm,pl310-cache"
- "arm,l220-cache"
- "arm,l210-cache"
- "marvell,aurora-system-cache": Marvell Controller designed to be
- compatible with the ARM one, with system cache mode (meaning
- maintenance operations on L1 are broadcasted to the L2 and L2
- performs the same operation).
- "marvell,"aurora-outer-cache: Marvell Controller designed to be
- compatible with the ARM one with outer cache mode.
- - cache-unified : Specifies the cache is a unified cache.
- - cache-level : Should be set to 2 for a level 2 cache.
- - reg : Physical base address and size of cache controller's memory mapped
- registers.
- Optional properties:
- - arm,data-latency : Cycles of latency for Data RAM accesses. Specifies 3 cells of
- read, write and setup latencies. Minimum valid values are 1. Controllers
- without setup latency control should use a value of 0.
- - arm,tag-latency : Cycles of latency for Tag RAM accesses. Specifies 3 cells of
- read, write and setup latencies. Controllers without setup latency control
- should use 0. Controllers without separate read and write Tag RAM latency
- values should only use the first cell.
- - arm,dirty-latency : Cycles of latency for Dirty RAMs. This is a single cell.
- - arm,filter-ranges : <start length> Starting address and length of window to
- filter. Addresses in the filter window are directed to the M1 port. Other
- addresses will go to the M0 port.
- - interrupts : 1 combined interrupt.
- - cache-id-part: cache id part number to be used if it is not present
- on hardware
- - wt-override: If present then L2 is forced to Write through mode
- Example:
- L2: cache-controller {
- compatible = "arm,pl310-cache";
- reg = <0xfff12000 0x1000>;
- arm,data-latency = <1 1 1>;
- arm,tag-latency = <2 2 2>;
- arm,filter-ranges = <0x80000000 0x8000000>;
- cache-unified;
- cache-level = <2>;
- interrupts = <45>;
- };
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