[PATCH] ARM: dts: bcm2711: Add the missing L1/L2 cache information

Richard Schleich rs at noreya.tech
Tue Dec 21 14:48:30 PST 2021


This patch fixes the kernel warning
"cacheinfo: Unable to detect cache hierarchy for CPU 0"
for the bcm2711 on newer kernel versions.

Signed-off-by: Richard Schleich <rs at noreya.tech>
---
 arch/arm/boot/dts/bcm2711.dtsi | 50 ++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
index 9e01dbca4a01..b2f403fc420c 100644
--- a/arch/arm/boot/dts/bcm2711.dtsi
+++ b/arch/arm/boot/dts/bcm2711.dtsi
@@ -458,12 +458,26 @@
 		#size-cells = <0>;
 		enable-method = "brcm,bcm2836-smp"; // for ARM 32-bit
 
+		/* Source for d/i-cache-line-size and d/i-cache-sets
+		 *  https://developer.arm.com/documentation/100095/0003
+		 *  /Level-1-Memory-System/About-the-L1-memory-system?lang=en
+		 * Source for d/i-cache-size
+		 *  https://www.raspberrypi.com/documentation/computers
+		 *  /processors.html#bcm2711
+		 */
 		cpu0: cpu at 0 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a72";
 			reg = <0>;
 			enable-method = "spin-table";
 			cpu-release-addr = <0x0 0x000000d8>;
+			d-cache-size = <0x8000>; // 32KB 2-way set-associative data cache
+			d-cache-line-size = <64>;// Fixed line length of 64 bytes
+			d-cache-sets = <256>; // 32KiB(size)/64(line-size)=512ways/2-way set
+			i-cache-size = <0xc000>; // 48kB 3-way set-associative data cache
+			i-cache-line-size = <64>;// Fixed line length of 64 bytes
+			i-cache-sets = <256>; // 48KiB(size)/64(line-size)=768ways/3-way set
+			next-level-cache = <&l2>;
 		};
 
 		cpu1: cpu at 1 {
@@ -472,6 +486,13 @@
 			reg = <1>;
 			enable-method = "spin-table";
 			cpu-release-addr = <0x0 0x000000e0>;
+			d-cache-size = <0x8000>; // 32KB 2-way set-associative data cache
+			d-cache-line-size = <64>;// Fixed line length of 64 bytes
+			d-cache-sets = <256>; // 32KiB(size)/64(line-size)=512ways/2-way set
+			i-cache-size = <0xc000>; // 48kB 3-way set-associative data cache
+			i-cache-line-size = <64>;// Fixed line length of 64 bytes
+			i-cache-sets = <256>; // 48KiB(size)/64(line-size)=768ways/3-way set
+			next-level-cache = <&l2>;
 		};
 
 		cpu2: cpu at 2 {
@@ -480,6 +501,13 @@
 			reg = <2>;
 			enable-method = "spin-table";
 			cpu-release-addr = <0x0 0x000000e8>;
+			d-cache-size = <0x8000>; // 32KB 2-way set-associative data cache
+			d-cache-line-size = <64>;// Fixed line length of 64 bytes
+			d-cache-sets = <256>; // 32KiB(size)/64(line-size)=512ways/2-way set
+			i-cache-size = <0xc000>; // 48kB 3-way set-associative data cache
+			i-cache-line-size = <64>;// Fixed line length of 64 bytes
+			i-cache-sets = <256>; // 48KiB(size)/64(line-size)=768ways/3-way set
+			next-level-cache = <&l2>;
 		};
 
 		cpu3: cpu at 3 {
@@ -488,6 +516,28 @@
 			reg = <3>;
 			enable-method = "spin-table";
 			cpu-release-addr = <0x0 0x000000f0>;
+			d-cache-size = <0x8000>; // 32KB 2-way set-associative data cache
+			d-cache-line-size = <64>;// Fixed line length of 64 bytes
+			d-cache-sets = <256>; // 32KiB(size)/64(line-size)=512ways/2-way set
+			i-cache-size = <0xc000>; // 48kB 3-way set-associative data cache
+			i-cache-line-size = <64>;// Fixed line length of 64 bytes
+			i-cache-sets = <256>; // 48KiB(size)/64(line-size)=768ways/3-way set
+			next-level-cache = <&l2>;
+		};
+
+		l2: l2-cache0 {
+			/* Source for d/i-cache-line-size and d/i-cache-sets
+			 *  https://developer.arm.com/documentation/100095/0003
+			 *  /Level-2-Memory-System/About-the-L2-memory-system?lang=en
+			 *  Source for d/i-cache-size
+			 *  https://www.raspberrypi.com/documentation/computers
+			 *  /processors.html#bcm2711
+			 */
+			compatible = "cache";
+			cache-size = <0x100000>; // 1MB
+			cache-line-size = <64>; // Fixed line length of 64 bytes
+			cache-sets = <1024>; // 1MiB(size)/64(line-size)=16000ways/16-way set
+			cache-level = <2>;
 		};
 	};
 
-- 
2.17.1




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