arm64: dts: ccimx8mm: add dynamic CMA and GPU memory sizing

Add support for dynamic CMA and GPU memory reservation based on total RAM.

This update fixes the Vivante GPU driver failing to load on 4 GiB RAM
devices when CMA is allocated near the end of RAM. The CMA range table
now allocates around the 2 GiB address.

https://onedigi.atlassian.net/browse/DEL-9575

Signed-off-by: Javier Viguera <javier.viguera@digi.com>

Author: jviguera

arch/arm64/boot/dts/digi/ccimx8mm-dvk.dts

@@ -298,6 +298,20 @@
 };
 
 &gpu {
+	/*
+	 * Use a table to set a fixed amount of contiguous memory used by the GPU
+	 * per memory configuration. This way we leave plenty of room for the
+	 * other system features when the memory is limited. The table's rows must
+	 * be in increasing RAM order. The GPU CMA should always be smaller than the
+	 * total CMA (see the table in the "reserved-memory" node to see the total CMA
+	 * values per memory configuration).
+	 */
+	digi,contiguous-size-table = <
+		/* RAM         CMA*/
+		0x0 0x40000000 0x0 0x08000000	/* 1 GB variants   -> 128 MB of GPU CMA */
+		0x0 0x80000000 0x0 0x10000000	/* 2 GB variants   -> 256 MB of GPU CMA */
+		0x1 0x00000000 0x0 0x20000000	/* 4 GB variants   -> 512 MB of GPU CMA */
+	>;
 	status = "okay";
 };
 

arch/arm64/boot/dts/digi/ccimx8mm.dtsi

@@ -108,14 +108,20 @@
 		ranges;
 
 		linux,cma {
+			compatible = "shared-dma-pool";
+			reusable;
+			/* Fallback size in case "digi,size-table" fails to parse */
+			size = <0 0x14000000>;
+			alloc-ranges =
+				<0 0x6A000000 0 0x14000000>,
+				<0 0x80000000 0 0x50000000>;
+			linux,cma-default;
 			digi,size-table = <
-				/* RAM         CMA*/
-				0x0 0x20000000 0x0 0x6000000	/* 512 MB variants -> 96 MB of CMA */
-				0x0 0x40000000 0x0 0x14000000	/* 1 GB variants   -> 320 MB of CMA */
-				0x0 0x80000000 0x0 0x28000000	/* 2 GB variants   -> 640 MB of CMA */
-				0x1 0x00000000 0x0 0x50000000	/* 4 GB variants   -> 1280 MB of CMA */
+				/* RAM          CMA */
+				0x0 0x40000000  0x0 0x14000000	/* 1 GB variants   -> 320 MB of CMA */
+				0x0 0x80000000  0x0 0x28000000	/* 2 GB variants   -> 640 MB of CMA */
+				0x1 0x00000000  0x0 0x50000000	/* 4 GB variants   -> 1280 MB of CMA */
 			>;
-			/delete-property/ alloc-ranges;
 		};
 	};