This patch adds the cache info for the BCM2835 and BCM2836.
However, while testing I noticed that this is
not implemented for ARMv6/7.
Basically arch/arm/kernel/cacheinfo.c and other topology
related code is missing.
Since the work is already done and this has no negative effects,
I am submitting it for future/documentation purposes.
Signed-off-by: Richard Schleich <rs@xxxxxxxxxxx>
---
arch/arm/boot/dts/bcm2835.dtsi | 17 ++++++++++++
arch/arm/boot/dts/bcm2836.dtsi | 50 ++++++++++++++++++++++++++++++++++
2 files changed, 67 insertions(+)
diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi
index 0549686134ea..1c90e5a44283 100644
--- a/arch/arm/boot/dts/bcm2835.dtsi
+++ b/arch/arm/boot/dts/bcm2835.dtsi
@@ -14,6 +14,23 @@ cpu@0 {
device_type = "cpu";
compatible = "arm,arm1176jzf-s";
reg = <0x0>;
+ /* Source for d/i-cache-line-size and d/i-cache-sets
+ * https://developer.arm.com/documentation/ddi0301
+ * /h/level-one-memory-system/cache-organization?lang=en
+ *
+ * Source for d/i-cache-size
+ * https://forums.raspberrypi.com/viewtopic.php?t=98428
+ *
+ * NOTE: The BCM2835 has a L2 cache but it is dedicated to the GPU
+ * It can be shared with the CPU through fw settings,
+ * but this is not recommended.
+ */
+ d-cache-size = <0x4000>;
+ d-cache-line-size = <16>;
+ d-cache-sets = <256>; // 16KiB(size)/16(line-size)=1024ways/4-way set
+ i-cache-size = <0x4000>;
+ i-cache-line-size = <16>;
+ i-cache-sets = <256>; // 16KiB(size)/16(line-size)=1024ways/4-way set
};
};
diff --git a/arch/arm/boot/dts/bcm2836.dtsi b/arch/arm/boot/dts/bcm2836.dtsi
index b390006aef79..534dacfc4dd5 100644
--- a/arch/arm/boot/dts/bcm2836.dtsi
+++ b/arch/arm/boot/dts/bcm2836.dtsi
@@ -41,11 +41,26 @@ cpus: cpus {
#size-cells = <0>;
enable-method = "brcm,bcm2836-smp";
+ /* Source for d/i-cache-line-size and d/i-cache-sets
+ * https://developer.arm.com/documentation/ddi0464/f/L1-Memory-System
+ * /About-the-L1-memory-system?lang=en
+ *
+ * Source for d/i-cache-size
+ * https://forums.raspberrypi.com/viewtopic.php?t=98428
+ */
+
v7_cpu0: cpu@0 {
device_type = "cpu";
compatible = "arm,cortex-a7";
reg = <0xf00>;
clock-frequency = <800000000>;
+ 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 = <32>;
+ i-cache-sets = <512>; // 32KiB(size)/32(line-size)=1024ways/2-way set
+ next-level-cache = <&l2>;
};
v7_cpu1: cpu@1 {
@@ -53,6 +68,13 @@ v7_cpu1: cpu@1 {
compatible = "arm,cortex-a7";
reg = <0xf01>;
clock-frequency = <800000000>;
+ 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 = <32>;
+ i-cache-sets = <512>; // 32KiB(size)/32(line-size)=1024ways/2-way set
+ next-level-cache = <&l2>;
};
v7_cpu2: cpu@2 {
@@ -60,6 +82,13 @@ v7_cpu2: cpu@2 {
compatible = "arm,cortex-a7";
reg = <0xf02>;
clock-frequency = <800000000>;
+ 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 = <32>;
+ i-cache-sets = <512>; // 32KiB(size)/32(line-size)=1024ways/2-way set
+ next-level-cache = <&l2>;
};
v7_cpu3: cpu@3 {
@@ -67,6 +96,27 @@ v7_cpu3: cpu@3 {
compatible = "arm,cortex-a7";
reg = <0xf03>;
clock-frequency = <800000000>;
+ 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 = <32>;
+ i-cache-sets = <512>; // 32KiB(size)/32(line-size)=1024ways/2-way set
+ next-level-cache = <&l2>;
+ };
+
+ /* Source for cache-line-size + cache-sets
+ * https://developer.arm.com/documentation/ddi0464/f/L2-Memory-System
+ * /About-the-L2-Memory-system?lang=en
+ * Source for cache-size
+ * https://forums.raspberrypi.com/viewtopic.php?t=98428
+ */
+ l2: l2-cache0 {
+ compatible = "cache";
+ cache-size = <0x80000>;
+ cache-line-size = <64>;
+ cache-sets = <1024>; // 512KiB(size)/64(line-size)=8192ways/8-way set
+ cache-level = <2>;
};
};
};
--
2.25.1
