Kernel-4.18.0-80.el8_renesas,smp-sra

  • Renesas SMP SRAM

Renesas R-Car Gen2 and RZ/G1 SoCs need a small piece of SRAM for the jump stub
for secondary CPU bringup and CPU hotplug.
This memory is reserved by adding a child node to a “mmio-sram” node, cfr.
Documentation/devicetree/bindings/sram/sram.txt.

Required child node properties:

  • compatible: Must be “renesas,smp-sram”,
  • reg: Address and length of the reserved SRAM.
    The full physical (bus) address must be aligned to a 256 KiB boundary.

Example:

icram1:    sram@e63c0000 {
    compatible = "mmio-sram";
    reg = <0 0xe63c0000 0 0x1000>;
    #address-cells = <1>;
    #size-cells = <1>;
    ranges = <0 0 0xe63c0000 0x1000>;

    smp-sram@0 {
        compatible = "renesas,smp-sram";
        reg = <0 0x10>;
    };
};