Openamp with vitis 2025.1 and kernel 6.12

[quentingaspart]

Hello,

I am encountering some problems in order to run openamp on kernel 6.12 (rpmsg_char on A53 and freertos on R5).
I was able to run some customs and demo app on a kernel 5.4 but i am trying to migrate to newer kernel version.
I have seen that some compilations flags must be added. (CONFIG_RPMSG_NS=y, CONFIG_RPMSG_CTRL=y, CONFIG_XLNX_R5_REMOTEPROC=y)

When I am trying to run a demo app in v6.12. I see the name server channel and the control channel. But no users channel is created.

I have tried several device tree configurations taking these examples:
https://github.com/OpenAMP/openamp-system-reference/blob/main/examples/linux/dts/xilinx/zynqmp-openamp.dtso
or
https://github.com/OpenAMP/openamp-system-reference/blob/main/examples/linux/dts/xilinx/xilinx-openamp-for-v6.x.dtso

but it does not work.

Could you tell me which one is the correct one to use and if I have to consider others changes in order to make openamp running.

Thanks in advance

[quentingaspart]

I suspect that something has changed regarding IPI channels used in the linux kernel but I don't see any documentation regarding the changes.

[tnmysh]

Hello, Thanks for your question.

Recently, the changes were introduced in system-reference xlnx dts as per 6.12 kernel.
OpenAMP/openamp-system-reference@d054602
Are you using same commit to build device-tree ?

Looks like RPU -> APU IPI interrupt may not be working. You can verify interrupt count of ipi interrupt using cat /proc/interrupts command.

Remoteproc nodes has changes in 6.12, but it doesn't have changes in IPI node. Also, changes in driver are backward compatibile, which means previous device-tree for zynqmp should work on 6.12 as well.

If you post your IPI-nodes, remoteproc node and reserved memory region nodes, I can review it and provide further assistance.

Thanks,
Tanmay

[tnmysh]

Also which board are you testing on ? We have tested this on zcu102 and kv260. Based on your board I can provide correct dtso / dtb to use.

[quentingaspart]

I am testing on a custom board with a zynq uz3eg.
It is running on a custom OS using yocto.
Our device tree is based on the ZCU102.
There is 2 Gb of RAM on our board so the address of the reserved memories are different.

I have updated the following values (tell me if I have to consider others values):

#define SHARED_MEM_PA  0x7C000000UL
#define SHARED_MEM_SIZE 0x100000UL
#define SHARED_BUF_OFFSET 0x8000UL
#define IPI_CHN_BITMASK         0x1000000

Here is the decompiled dtb extract you ask

reserved-memory {
		#address-cells = < 0x02 >;
		#size-cells = < 0x02 >;
		ranges;

		rpu0vdev0vring0@7c000000 {
			no-map;
			reg = < 0x00 0x7c000000 0x00 0x4000 >;
			phandle = < 0x22 >;
		};

		rpu0vdev0vring1@7c004000 {
			no-map;
			reg = < 0x00 0x7c004000 0x00 0x4000 >;
			phandle = < 0x23 >;
		};

		rpu0vdev0buffer@7c008000 {
			no-map;
			reg = < 0x00 0x7c008000 0x00 0x100000 >;
			phandle = < 0x21 >;
		};

		rproc_0_fw_image@7c108000 {
			no-map;
			reg = < 0x00 0x7c108000 0x00 0x1ef8000 >;
			phandle = < 0x20 >;
		};

		rpu1vdev0vring0@7e000000 {
			no-map;
			reg = < 0x00 0x7e000000 0x00 0x4000 >;
			phandle = < 0x27 >;
		};

		rpu1vdev0vring1@7e004000 {
			no-map;
			reg = < 0x00 0x7e004000 0x00 0x4000 >;
			phandle = < 0x28 >;
		};

		rpu1vdev0buffer@7e008000 {
			no-map;
			reg = < 0x00 0x7e008000 0x00 0x100000 >;
			phandle = < 0x26 >;
		};

		rproc_1_fw_image@7e108000 {
			no-map;
			reg = < 0x00 0x7e108000 0x00 0x1ef8000 >;
			phandle = < 0x25 >;
		};
	};

	zynqmp_ipi1 {
		compatible = "xlnx,zynqmp-ipi-mailbox";
		interrupt-parent = < 0x05 >;
		interrupts = < 0x00 0x1d 0x04 >;
		xlnx,ipi-id = < 0x07 >;
		#address-cells = < 0x01 >;
		#size-cells = < 0x01 >;
		ranges;

		mailbox@ff990600 {
			reg = < 0xff990600 0x20 0xff990620 0x20 0xff9900c0 0x20 0xff9900e0 0x20 >;
			reg-names = "local_request_region\0local_response_region\0remote_request_region\0remote_response_region";
			#mbox-cells = < 0x01 >;
			xlnx,ipi-id = < 0x01 >;
			phandle = < 0x24 >;
		};
	};

	rf5ss@ff9a0000 {
		compatible = "xlnx,zynqmp-r5fss";
		xlnx,cluster-mode = < 0x00 >;
		xlnx,tcm-mode = < 0x00 >;
		#address-cells = < 0x02 >;
		#size-cells = < 0x02 >;
		ranges = < 0x00 0x00 0x00 0xffe00000 0x00 0x10000 0x00 0x20000 0x00 0xffe20000 0x00 0x10000 0x01 0x00 0x00 0xffe90000 0x00 0x10000 0x01 0x20000 0x00 0xffeb0000 0x00 0x10000 >;

		r5f@0 {
			compatible = "xlnx,zynqmp-r5f";
			reg = < 0x00 0x00 0x00 0x10000 0x00 0x20000 0x00 0x10000 >;
			reg-names = "atcm0\0btcm0";
			power-domains = < 0x12 0x07 0x12 0x0f 0x12 0x10 >;
			memory-region = < 0x20 0x21 0x22 0x23 >;
			mboxes = < 0x24 0x00 0x24 0x01 >;
			mbox-names = "tx\0rx";
			phandle = < 0x8e >;
		};

		r5f@1 {
			compatible = "xlnx,zynqmp-r5f";
			reg = < 0x01 0x00 0x00 0x10000 0x01 0x20000 0x00 0x10000 >;
			reg-names = "atcm0\0btcm0";
			power-domains = < 0x12 0x08 0x12 0x11 0x12 0x12 >;
			memory-region = < 0x25 0x26 0x27 0x28 >;
			mboxes = < 0x29 0x00 0x29 0x01 >;
			mbox-names = "tx\0rx";
			phandle = < 0x8f >;
		};
	};

equivalent .dtsi version

/ {
    reserved-memory {
        #address-cells = <2>;
        #size-cells = <2>;
        ranges;
        rpu0vdev0vring0: rpu0vdev0vring0@7c000000 {
			no-map;
			reg = <0x0 0x7c000000 0x0 0x4000>;
		};
		rpu0vdev0vring1: rpu0vdev0vring1@7c004000 {
			no-map;
			reg = <0x0 0x7c004000 0x0 0x4000>;
		};
		rpu0vdev0buffer: rpu0vdev0buffer@7c008000 {
			no-map;
			reg = <0x0 0x7c008000 0x0 0x100000>;
		};
		rproc_0_fw_image: rproc_0_fw_image@7c108000 {
			no-map;
			reg = <0x0 0x7c108000 0x0 0x1ef8000>;
		};

		rpu1vdev0vring0: rpu1vdev0vring0@7e000000 {
			no-map;
			reg = <0x0 0x7e000000 0x0 0x4000>;
		};
		rpu1vdev0vring1: rpu1vdev0vring1@7e004000 {
			no-map;
			reg = <0x0 0x7e004000 0x0 0x4000>;
		};
		rpu1vdev0buffer: rpu1vdev0buffer@7e008000 {
			no-map;
			reg = <0x0 0x7e008000 0x0 0x100000>;
		};
		rproc_1_fw_image: rproc_1_fw_image@7e108000 {
			no-map;
			reg = <0x0 0x7e108000 0x0 0x1ef8000>;
		};
	};

	zynqmp_ipi1 {
		compatible = "xlnx,zynqmp-ipi-mailbox";
		interrupt-parent = <&gic>;
		interrupts = <0x00 0x1d 0x04>;
		xlnx,ipi-id = <0x07>;        /* bare-metal apps send on channel 7 */
		#address-cells = <0x01>;
		#size-cells = <0x01>;
		ranges;

		ipi_mailbox_rpu0: mailbox@ff990600 {
			reg = <0xff990600 0x20>,
			      <0xff990620 0x20>,
			      <0xff9900c0 0x20>,
			      <0xff9900e0 0x20>;
			reg-names = "local_request_region",
			            "local_response_region",
				    "remote_request_region",
				    "remote_response_region";
			#mbox-cells = <0x01>;
			xlnx,ipi-id = <0x01>;    /* host still sends to RPU0 on ch 1 */
		};
	};

		ipi_mailbox_rpu1: mailbox@ff990420 {
			reg = <0x00 0xff990420 0x00 0x20>,
			      <0x00 0xff990440 0x00 0x20>,
			      <0x00 0xff990260 0x00 0x20>,
			      <0x00 0xff990280 0x00 0x20>;
			reg-names = "local_request_region",
				    "local_response_region",
				    "remote_request_region",
				    "remote_response_region";
			#mbox-cells = <0x01>;
			xlnx,ipi-id = <0x02>;
		};
	};

	rf5ss@ff9a0000 {
		compatible = "xlnx,zynqmp-r5fss";
		xlnx,cluster-mode = <0>;
		xlnx,tcm-mode = <0>;

		#address-cells = <0x2>;
		#size-cells = <0x2>;
		ranges = <0x0 0x0 0x0 0xffe00000 0x0 0x10000>,
					<0x0 0x20000 0x0 0xffe20000 0x0 0x10000>,
					<0x1 0x0 0x0 0xffe90000 0x0 0x10000>,
					<0x1 0x20000 0x0 0xffeb0000 0x0 0x10000>;

		r5f_0: r5f@0 {
			compatible = "xlnx,zynqmp-r5f";
			reg = <0x0 0x0 0x0 0x10000>, <0x0 0x20000 0x0 0x10000>;
			reg-names = "atcm0", "btcm0";
			power-domains = <&zynqmp_firmware 7>,
							<&zynqmp_firmware 15>,
							<&zynqmp_firmware 16>;
			memory-region = <&rproc_0_fw_image>, <&rpu0vdev0buffer>,
							<&rpu0vdev0vring0>, <&rpu0vdev0vring1>;
			mboxes = <&ipi_mailbox_rpu0 0>, <&ipi_mailbox_rpu0 1>;
			mbox-names = "tx", "rx";
		};
		r5f_1: r5f@1 {
			compatible = "xlnx,zynqmp-r5f";
			reg = <0x1 0x0 0x0 0x10000>, <0x1 0x20000 0x0 0x10000>;
			reg-names = "atcm0", "btcm0";
			power-domains = <&zynqmp_firmware 8>,
							<&zynqmp_firmware 17>,
							<&zynqmp_firmware 18>;
			memory-region = <&rproc_1_fw_image>, <&rpu1vdev0buffer>,
							<&rpu1vdev0vring0>, <&rpu1vdev0vring1>;
			mboxes = <&ipi_mailbox_rpu1 0>, <&ipi_mailbox_rpu1 1>;
			mbox-names = "tx", "rx";
		};
	};
};

Just for me to know, could you tell me how the IPI message buffers address are selected regarding the IPI channels ?

For the interrupts, I will check tomorrow on the target.

Thanks for your help !

[tnmysh]

With 6.12 kernel there are new bindings in effect:

https://github.com/torvalds/linux/blob/v6.12/Documentation/devicetree/bindings/remoteproc/xlnx%2Czynqmp-r5fss.yaml

With new bindings following is expected:

1. reserved memory regions should drop "rpu0" and "rpu1" prefix in node name.
   rpu0vdev0vring0@xxxx -> vdev0vring0@xxxx
   rpu0vdev1vring0@xxxx -> vdev0vring1@xxxx
   etc..

2. cluster node name should be remoteproc not rf5ss

rf5ss@ff9a0000 {

https://github.com/torvalds/linux/blob/v6.12/Documentation/devicetree/bindings/remoteproc/xlnx%2Czynqmp-r5fss.yaml#L281

3. I see that address-cells and size-cells are set to 1, but IPI-1 has reg representation with 2 addresss cells and 2 size cells that should be fixed.

Just for me to know, could you tell me how the IPI message buffers address are selected regarding the IPI channels ?

Please refer here: https://docs.amd.com/v/u/en-US/ug1085-zynq-ultrascale-trm -> Page 318.
"IPI Channel and Message Buffer Default Associations"

Ideally any buffer is fine as long as both side (Linux and remote) uses same address space.