[PATCH v2 3/3] arm64: dts: microchip: sparx5: add missing L1/L2 cache information

Robert Marko robert.marko at sartura.hr
Tue Feb 21 02:50:39 PST 2023


Currently, when booting on SparX-5 you will get the following error:
[    0.050132] Early cacheinfo failed, ret = -22

This is due to L2 cache node missing cache-level property to indicate its
level, so populate it to let the kernel know its L2 cache.

However, that alone is enough to get rid of the error, but then the
following warnings appear:
[    0.050162] cacheinfo: Unable to detect cache hierarchy for CPU 0
[    0.093256] cacheinfo: Unable to detect cache hierarchy for CPU 1

So, lets completely populate both the L1 and L2 cache info based off the
SoC datasheet[1] and ARM A53 technical reference manual[2].

Now "lscpu -C" provides:
NAME ONE-SIZE ALL-SIZE WAYS TYPE        LEVEL SETS PHY-LINE COHERENCY-SIZE
L1d       32K      64K    4 Data            1  128                      64
L1i       32K      64K    2 Instruction     1  256                      64
L2       256K     256K   16 Unified         2  256                      64

Tested on PCB134 (eMMC).

[1] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/DataSheets/SparX-5_Family_L2L3_Enterprise_25G_Ethernet_Switches_Datasheet_00003823D.pdf
[2] https://developer.arm.com/documentation/ddi0500/j/Level-1-Memory-System/About-the-L1-memory-system?lang=en

Fixes: 6694aee00a4b ("arm64: dts: sparx5: Add basic cpu support")
Signed-off-by: Robert Marko <robert.marko at sartura.hr>
---
 arch/arm64/boot/dts/microchip/sparx5.dtsi | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/arm64/boot/dts/microchip/sparx5.dtsi b/arch/arm64/boot/dts/microchip/sparx5.dtsi
index a4fabacf5c2f7..950ba78bf73f3 100644
--- a/arch/arm64/boot/dts/microchip/sparx5.dtsi
+++ b/arch/arm64/boot/dts/microchip/sparx5.dtsi
@@ -41,6 +41,12 @@ cpu0: cpu at 0 {
 			device_type = "cpu";
 			reg = <0x0>;
 			enable-method = "psci";
+			d-cache-size = <0x8000>;
+			d-cache-line-size = <64>;
+			d-cache-sets = <128>; // 32KiB(size)/64(line-size)=512ways/4-way set
+			i-cache-size = <0x8000>;
+			i-cache-line-size = <64>;
+			i-cache-sets = <256>; // 32KiB(size)/64(line-size)=512ways/2-way set
 			next-level-cache = <&L2_0>;
 		};
 		cpu1: cpu at 1 {
@@ -48,10 +54,21 @@ cpu1: cpu at 1 {
 			device_type = "cpu";
 			reg = <0x1>;
 			enable-method = "psci";
+			d-cache-size = <0x8000>;
+			d-cache-line-size = <64>;
+			d-cache-sets = <128>; // 32KiB(size)/64(line-size)=512ways/4-way set
+			i-cache-size = <0x8000>;
+			i-cache-line-size = <64>;
+			i-cache-sets = <256>; // 32KiB(size)/64(line-size)=512ways/2-way set
 			next-level-cache = <&L2_0>;
 		};
 		L2_0: l2-cache0 {
 			compatible = "cache";
+			cache-unified;
+			cache-size = <0x40000>;
+			cache-line-size = <64>;
+			cache-sets = <256>; // 256KB(size)/64(line-size)=4096ways/16-way set
+			cache-level = <2>;
 		};
 	};
 
-- 
2.39.2




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