bifrost/r25p0/kernel/Documentation/devicetree/bindings/arm/protected_memory_allocator.txt

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* Arm protected memory allocator for Mali GPU device drivers

Required properties:

- compatible: Must be "arm,protected-memory-allocator"

The protected memory allocator manages allocation of physical pages of a
reserved memory region of protected memory, therefore its device node shall
reference a reserved memory region.

In addition to that, the protected memory allocator shall be referenced
by the GPU.

A complete example configuration for the device tree:

	reserved-memory {
		#address-cells = <2>;
		#size-cells = <2>;
		ranges;

		mali_protected: mali_protected@c0000000 {
			compatible = "mali-reserved";
			reg = <0x0 0xc0000000 0x0 0x1000000>;
		};
	};

	gpu_protected_memory_allocator: protected-memory-allocator {
		compatible = "arm,protected-memory-allocator";
		memory-region = <&mali_protected>;
	};

	gpu_fpga: gpu@0x6e000000 {
		compatible = "arm,mali-midgard";
		reg = <0x0 0x6e000000 0x0 0x200000>;
		interrupts = <0 168 4>, <0 168 4>, <0 168 4>;
		interrupt-names = "JOB", "MMU", "GPU";
		clocks = <&scpi_dvfs 2>;
		clock-names = "clk_mali";
		protected-memory-allocator = <&gpu_protected_memory_allocator>;
		operating-points = <
			/* KHz uV */
			50000 820000
		>;
	};

The protected memory allocator is gpu_protected_memory_allocator.
It references the mali_protected reserved memory region and, in turn,
it is referenced by the GPU as protected-memory-allocator.