l2cc.txt 2.4 KB

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  1. * ARM L2 Cache Controller
  2. ARM cores often have a separate level 2 cache controller. There are various
  3. implementations of the L2 cache controller with compatible programming models.
  4. The ARM L2 cache representation in the device tree should be done as follows:
  5. Required properties:
  6. - compatible : should be one of:
  7. "arm,pl310-cache"
  8. "arm,l220-cache"
  9. "arm,l210-cache"
  10. "marvell,aurora-system-cache": Marvell Controller designed to be
  11. compatible with the ARM one, with system cache mode (meaning
  12. maintenance operations on L1 are broadcasted to the L2 and L2
  13. performs the same operation).
  14. "marvell,"aurora-outer-cache: Marvell Controller designed to be
  15. compatible with the ARM one with outer cache mode.
  16. "brcm,bcm11351-a2-pl310-cache": For Broadcom bcm11351 chipset where an
  17. offset needs to be added to the address before passing down to the L2
  18. cache controller
  19. "bcm,bcm11351-a2-pl310-cache": DEPRECATED by
  20. "brcm,bcm11351-a2-pl310-cache"
  21. - cache-unified : Specifies the cache is a unified cache.
  22. - cache-level : Should be set to 2 for a level 2 cache.
  23. - reg : Physical base address and size of cache controller's memory mapped
  24. registers.
  25. Optional properties:
  26. - arm,data-latency : Cycles of latency for Data RAM accesses. Specifies 3 cells of
  27. read, write and setup latencies. Minimum valid values are 1. Controllers
  28. without setup latency control should use a value of 0.
  29. - arm,tag-latency : Cycles of latency for Tag RAM accesses. Specifies 3 cells of
  30. read, write and setup latencies. Controllers without setup latency control
  31. should use 0. Controllers without separate read and write Tag RAM latency
  32. values should only use the first cell.
  33. - arm,dirty-latency : Cycles of latency for Dirty RAMs. This is a single cell.
  34. - arm,filter-ranges : <start length> Starting address and length of window to
  35. filter. Addresses in the filter window are directed to the M1 port. Other
  36. addresses will go to the M0 port.
  37. - interrupts : 1 combined interrupt.
  38. - cache-id-part: cache id part number to be used if it is not present
  39. on hardware
  40. - wt-override: If present then L2 is forced to Write through mode
  41. Example:
  42. L2: cache-controller {
  43. compatible = "arm,pl310-cache";
  44. reg = <0xfff12000 0x1000>;
  45. arm,data-latency = <1 1 1>;
  46. arm,tag-latency = <2 2 2>;
  47. arm,filter-ranges = <0x80000000 0x8000000>;
  48. cache-unified;
  49. cache-level = <2>;
  50. interrupts = <45>;
  51. };