[PATCH] arm64: dts: broadcom: Fix L2 linesize for Raspberry Pi 5

[PATCH] arm64: dts: broadcom: Fix L2 linesize for Raspberry Pi 5

[Willow Cunningham]

From: Willow Cunningham <willow.e.cunningham@gmail.com>

Fixes: faa3381267d0 ("arm64: dts: broadcom: Add minimal support for
Raspberry Pi 5")

Set the cache-line-size parameter of the L2 cache for each core to the
correct value of 64 bytes.

Previously, the L2 cache line size was incorrectly set to 128 bytes
for the Broadcom BCM2712. This causes validation tests for the
Performance Application Programming Interface (PAPI) tool to fail as
they depend on sysfs accurately reporting cache line sizes.

The correct value of 64 bytes is stated in the official documentation of
the ARM Cortex A-72, which is linked in the comments of
arm64/boot/dts/broadcom/bcm2712.dtsi as the source for cache-line-size.

Signed-off-by: Willow Cunningham <willow.e.cunningham@maine.edu>
---
 arch/arm64/boot/dts/broadcom/bcm2712.dtsi | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/broadcom/bcm2712.dtsi b/arch/arm64/boot/dts/broadcom/bcm2712.dtsi
index 6e5a984c1d4e..26a29e5e5078 100644
--- a/arch/arm64/boot/dts/broadcom/bcm2712.dtsi
+++ b/arch/arm64/boot/dts/broadcom/bcm2712.dtsi
@@ -67,7 +67,7 @@ cpu0: cpu@0 {
 			l2_cache_l0: l2-cache-l0 {
 				compatible = "cache";
 				cache-size = <0x80000>;
-				cache-line-size = <128>;
+				cache-line-size = <64>;
 				cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
 				cache-level = <2>;
 				cache-unified;
@@ -91,7 +91,7 @@ cpu1: cpu@1 {
 			l2_cache_l1: l2-cache-l1 {
 				compatible = "cache";
 				cache-size = <0x80000>;
-				cache-line-size = <128>;
+				cache-line-size = <64>;
 				cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
 				cache-level = <2>;
 				cache-unified;
@@ -115,7 +115,7 @@ cpu2: cpu@2 {
 			l2_cache_l2: l2-cache-l2 {
 				compatible = "cache";
 				cache-size = <0x80000>;
-				cache-line-size = <128>;
+				cache-line-size = <64>;
 				cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
 				cache-level = <2>;
 				cache-unified;
@@ -139,7 +139,7 @@ cpu3: cpu@3 {
 			l2_cache_l3: l2-cache-l3 {
 				compatible = "cache";
 				cache-size = <0x80000>;
-				cache-line-size = <128>;
+				cache-line-size = <64>;
 				cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
 				cache-level = <2>;
 				cache-unified;
-- 
2.39.2

Re: [PATCH] arm64: dts: broadcom: Fix L2 linesize for Raspberry Pi 5

[Conor Dooley]

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On Thu, Oct 10, 2024 at 11:04:07AM -0400, Willow Cunningham wrote:
> From: Willow Cunningham <willow.e.cunningham@gmail.com>
> 
> Fixes: faa3381267d0 ("arm64: dts: broadcom: Add minimal support for
> Raspberry Pi 5")

This btw Willow, is meant to be...

> 
> Set the cache-line-size parameter of the L2 cache for each core to the
> correct value of 64 bytes.
> 
> Previously, the L2 cache line size was incorrectly set to 128 bytes
> for the Broadcom BCM2712. This causes validation tests for the
> Performance Application Programming Interface (PAPI) tool to fail as
> they depend on sysfs accurately reporting cache line sizes.
> 
> The correct value of 64 bytes is stated in the official documentation of
> the ARM Cortex A-72, which is linked in the comments of
> arm64/boot/dts/broadcom/bcm2712.dtsi as the source for cache-line-size.
> 

> Signed-off-by: Willow Cunningham <willow.e.cunningham@maine.edu>

Down here, on the line before your signoff. Perhaps Florian is willing
to fix that for you though.

Cheers,
Conor.

> ---
>  arch/arm64/boot/dts/broadcom/bcm2712.dtsi | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/broadcom/bcm2712.dtsi b/arch/arm64/boot/dts/broadcom/bcm2712.dtsi
> index 6e5a984c1d4e..26a29e5e5078 100644
> --- a/arch/arm64/boot/dts/broadcom/bcm2712.dtsi
> +++ b/arch/arm64/boot/dts/broadcom/bcm2712.dtsi
> @@ -67,7 +67,7 @@ cpu0: cpu@0 {
>  			l2_cache_l0: l2-cache-l0 {
>  				compatible = "cache";
>  				cache-size = <0x80000>;
> -				cache-line-size = <128>;
> +				cache-line-size = <64>;
>  				cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
>  				cache-level = <2>;
>  				cache-unified;
> @@ -91,7 +91,7 @@ cpu1: cpu@1 {
>  			l2_cache_l1: l2-cache-l1 {
>  				compatible = "cache";
>  				cache-size = <0x80000>;
> -				cache-line-size = <128>;
> +				cache-line-size = <64>;
>  				cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
>  				cache-level = <2>;
>  				cache-unified;
> @@ -115,7 +115,7 @@ cpu2: cpu@2 {
>  			l2_cache_l2: l2-cache-l2 {
>  				compatible = "cache";
>  				cache-size = <0x80000>;
> -				cache-line-size = <128>;
> +				cache-line-size = <64>;
>  				cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
>  				cache-level = <2>;
>  				cache-unified;
> @@ -139,7 +139,7 @@ cpu3: cpu@3 {
>  			l2_cache_l3: l2-cache-l3 {
>  				compatible = "cache";
>  				cache-size = <0x80000>;
> -				cache-line-size = <128>;
> +				cache-line-size = <64>;
>  				cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
>  				cache-level = <2>;
>  				cache-unified;
> -- 
> 2.39.2
> 

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Re: [PATCH] arm64: dts: broadcom: Fix L2 linesize for Raspberry Pi 5

[Florian Fainelli]

On 10/10/24 09:30, Conor Dooley wrote:
> On Thu, Oct 10, 2024 at 11:04:07AM -0400, Willow Cunningham wrote:
>> From: Willow Cunningham <willow.e.cunningham@gmail.com>
>>
>> Fixes: faa3381267d0 ("arm64: dts: broadcom: Add minimal support for
>> Raspberry Pi 5")
> 
> This btw Willow, is meant to be...
> 
>>
>> Set the cache-line-size parameter of the L2 cache for each core to the
>> correct value of 64 bytes.
>>
>> Previously, the L2 cache line size was incorrectly set to 128 bytes
>> for the Broadcom BCM2712. This causes validation tests for the
>> Performance Application Programming Interface (PAPI) tool to fail as
>> they depend on sysfs accurately reporting cache line sizes.
>>
>> The correct value of 64 bytes is stated in the official documentation of
>> the ARM Cortex A-72, which is linked in the comments of
>> arm64/boot/dts/broadcom/bcm2712.dtsi as the source for cache-line-size.
>>
> 
>> Signed-off-by: Willow Cunningham <willow.e.cunningham@maine.edu>
> 
> Down here, on the line before your signoff. Perhaps Florian is willing
> to fix that for you though.

Yeah, I will fix it up while applying.
-- 
Florian

Re: [PATCH] arm64: dts: broadcom: Fix L2 linesize for Raspberry Pi 5

[Florian Fainelli]

On 10/10/24 08:04, Willow Cunningham wrote:
> From: Willow Cunningham <willow.e.cunningham@gmail.com>
> 
> Fixes: faa3381267d0 ("arm64: dts: broadcom: Add minimal support for
> Raspberry Pi 5")
> 
> Set the cache-line-size parameter of the L2 cache for each core to the
> correct value of 64 bytes.
> 
> Previously, the L2 cache line size was incorrectly set to 128 bytes
> for the Broadcom BCM2712. This causes validation tests for the
> Performance Application Programming Interface (PAPI) tool to fail as
> they depend on sysfs accurately reporting cache line sizes.
> 
> The correct value of 64 bytes is stated in the official documentation of
> the ARM Cortex A-72, which is linked in the comments of
> arm64/boot/dts/broadcom/bcm2712.dtsi as the source for cache-line-size.
> 
> Signed-off-by: Willow Cunningham <willow.e.cunningham@maine.edu>

Applied, thanks!
-- 
Florian