[PATCH] arm64: dts: allwinner: Add cache information to the SoC dtsi for A64

Dragan Simic dsimic at manjaro.org
Sun Apr 28 04:40:35 PDT 2024


Add missing cache information to the Allwinner A64 SoC dtsi, to allow
the userspace, which includes lscpu(1) that uses the virtual files provided
by the kernel under the /sys/devices/system/cpu directory, to display the
proper A64 cache information.

While there, use a more self-descriptive label for the L2 cache node, which
also makes it more consistent with other SoC dtsi files.

The cache parameters for the A64 dtsi were obtained and partially derived
by hand from the cache size and layout specifications found in the following
datasheets and technical reference manuals:

  - Allwinner A64 datasheet, version 1.1
  - ARM Cortex-A53 revision r0p3 TRM, version E

For future reference, here's a brief summary of the documentation:

  - All caches employ the 64-byte cache line length
  - Each Cortex-A53 core has 32 KB of L1 2-way, set-associative instruction
    cache and 32 KB of L1 4-way, set-associative data cache
  - The entire SoC has 512 KB of unified L2 16-way, set-associative cache

Signed-off-by: Dragan Simic <dsimic at manjaro.org>
---
 arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 37 ++++++++++++++++---
 1 file changed, 32 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
index 57ac18738c99..86074d03afa9 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
@@ -51,49 +51,76 @@ cpu0: cpu at 0 {
 			device_type = "cpu";
 			reg = <0>;
 			enable-method = "psci";
-			next-level-cache = <&L2>;
 			clocks = <&ccu CLK_CPUX>;
 			clock-names = "cpu";
 			#cooling-cells = <2>;
+			i-cache-size = <0x8000>;
+			i-cache-line-size = <64>;
+			i-cache-sets = <256>;
+			d-cache-size = <0x8000>;
+			d-cache-line-size = <64>;
+			d-cache-sets = <128>;
+			next-level-cache = <&l2_cache>;
 		};
 
 		cpu1: cpu at 1 {
 			compatible = "arm,cortex-a53";
 			device_type = "cpu";
 			reg = <1>;
 			enable-method = "psci";
-			next-level-cache = <&L2>;
 			clocks = <&ccu CLK_CPUX>;
 			clock-names = "cpu";
 			#cooling-cells = <2>;
+			i-cache-size = <0x8000>;
+			i-cache-line-size = <64>;
+			i-cache-sets = <256>;
+			d-cache-size = <0x8000>;
+			d-cache-line-size = <64>;
+			d-cache-sets = <128>;
+			next-level-cache = <&l2_cache>;
 		};
 
 		cpu2: cpu at 2 {
 			compatible = "arm,cortex-a53";
 			device_type = "cpu";
 			reg = <2>;
 			enable-method = "psci";
-			next-level-cache = <&L2>;
 			clocks = <&ccu CLK_CPUX>;
 			clock-names = "cpu";
 			#cooling-cells = <2>;
+			i-cache-size = <0x8000>;
+			i-cache-line-size = <64>;
+			i-cache-sets = <256>;
+			d-cache-size = <0x8000>;
+			d-cache-line-size = <64>;
+			d-cache-sets = <128>;
+			next-level-cache = <&l2_cache>;
 		};
 
 		cpu3: cpu at 3 {
 			compatible = "arm,cortex-a53";
 			device_type = "cpu";
 			reg = <3>;
 			enable-method = "psci";
-			next-level-cache = <&L2>;
 			clocks = <&ccu CLK_CPUX>;
 			clock-names = "cpu";
 			#cooling-cells = <2>;
+			i-cache-size = <0x8000>;
+			i-cache-line-size = <64>;
+			i-cache-sets = <256>;
+			d-cache-size = <0x8000>;
+			d-cache-line-size = <64>;
+			d-cache-sets = <128>;
+			next-level-cache = <&l2_cache>;
 		};
 
-		L2: l2-cache {
+		l2_cache: l2-cache {
 			compatible = "cache";
 			cache-level = <2>;
 			cache-unified;
+			cache-size = <0x80000>;
+			cache-line-size = <64>;
+			cache-sets = <512>;
 		};
 	};
 



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