[PATCH v2] platform/x86/intel-uncore-freq: Do not present separate package-die domain

[PATCH v2] platform/x86/intel-uncore-freq: Do not present separate package-die domain

[Srinivas Pandruvada]

The scope of uncore control is per power domain with TPMI.

There are two types of processor topologies can be presented by CPUID
extended topology leaf irrespective of the hardware architecture:

1. A die is not enumerated in CPUID. In this case there is only one die
in a package is visible. In this case there can be multiple power domains
in a single die.
2. A power domain in a package is enumerated as a die in CPUID. So
there is one power domain per die.

To allow die level controls, the current implementation creates a root
domain and aggregates all information from power domains in it. This
is well suited for configuration 1 above.

But for configuration 2 above, the root domain will present the same
information as present by power domain. So, no use of aggregating. To
check the configuration, call topology_max_dies_per_package(). If it is
more than one, avoid creating root domain.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
This is a forward looking change as TPMI is architectural and should
support all topologies.

v2
Updated commit description as suggested.

 .../x86/intel/uncore-frequency/uncore-frequency-tpmi.c     | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c
index 2016acf44f6a..e6047fbbea76 100644
--- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c
+++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c
@@ -557,6 +557,9 @@ static int uncore_probe(struct auxiliary_device *auxdev, const struct auxiliary_
 
 	auxiliary_set_drvdata(auxdev, tpmi_uncore);
 
+	if (topology_max_dies_per_package() > 1)
+		return 0;
+
 	tpmi_uncore->root_cluster.root_domain = true;
 	tpmi_uncore->root_cluster.uncore_root = tpmi_uncore;
 
@@ -580,7 +583,9 @@ static void uncore_remove(struct auxiliary_device *auxdev)
 {
 	struct tpmi_uncore_struct *tpmi_uncore = auxiliary_get_drvdata(auxdev);
 
-	uncore_freq_remove_die_entry(&tpmi_uncore->root_cluster.uncore_data);
+	if (tpmi_uncore->root_cluster.root_domain)
+		uncore_freq_remove_die_entry(&tpmi_uncore->root_cluster.uncore_data);
+
 	remove_cluster_entries(tpmi_uncore);
 
 	uncore_freq_common_exit();
-- 
2.45.0

Re: [PATCH v2] platform/x86/intel-uncore-freq: Do not present separate package-die domain

[Ilpo Järvinen]

[-- Attachment #1: Type: text/plain, Size: 2610 bytes --]

On Tue, 20 Aug 2024, Srinivas Pandruvada wrote:

> The scope of uncore control is per power domain with TPMI.
> 
> There are two types of processor topologies can be presented by CPUID
> extended topology leaf irrespective of the hardware architecture:
> 
> 1. A die is not enumerated in CPUID. In this case there is only one die
> in a package is visible. In this case there can be multiple power domains
> in a single die.
> 2. A power domain in a package is enumerated as a die in CPUID. So
> there is one power domain per die.
> 
> To allow die level controls, the current implementation creates a root
> domain and aggregates all information from power domains in it. This
> is well suited for configuration 1 above.
> 
> But for configuration 2 above, the root domain will present the same
> information as present by power domain. So, no use of aggregating. To
> check the configuration, call topology_max_dies_per_package(). If it is
> more than one, avoid creating root domain.
> 
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

-- 
 i.

> ---
> This is a forward looking change as TPMI is architectural and should
> support all topologies.
> 
> v2
> Updated commit description as suggested.
> 
>  .../x86/intel/uncore-frequency/uncore-frequency-tpmi.c     | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c
> index 2016acf44f6a..e6047fbbea76 100644
> --- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c
> +++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c
> @@ -557,6 +557,9 @@ static int uncore_probe(struct auxiliary_device *auxdev, const struct auxiliary_
>  
>  	auxiliary_set_drvdata(auxdev, tpmi_uncore);
>  
> +	if (topology_max_dies_per_package() > 1)
> +		return 0;
> +
>  	tpmi_uncore->root_cluster.root_domain = true;
>  	tpmi_uncore->root_cluster.uncore_root = tpmi_uncore;
>  
> @@ -580,7 +583,9 @@ static void uncore_remove(struct auxiliary_device *auxdev)
>  {
>  	struct tpmi_uncore_struct *tpmi_uncore = auxiliary_get_drvdata(auxdev);
>  
> -	uncore_freq_remove_die_entry(&tpmi_uncore->root_cluster.uncore_data);
> +	if (tpmi_uncore->root_cluster.root_domain)
> +		uncore_freq_remove_die_entry(&tpmi_uncore->root_cluster.uncore_data);
> +
>  	remove_cluster_entries(tpmi_uncore);
>  
>  	uncore_freq_common_exit();
> 

Re: [PATCH v2] platform/x86/intel-uncore-freq: Do not present separate package-die domain

[Hans de Goede]

Hi,

On 8/20/24 10:45 PM, Srinivas Pandruvada wrote:
> The scope of uncore control is per power domain with TPMI.
> 
> There are two types of processor topologies can be presented by CPUID
> extended topology leaf irrespective of the hardware architecture:
> 
> 1. A die is not enumerated in CPUID. In this case there is only one die
> in a package is visible. In this case there can be multiple power domains
> in a single die.
> 2. A power domain in a package is enumerated as a die in CPUID. So
> there is one power domain per die.
> 
> To allow die level controls, the current implementation creates a root
> domain and aggregates all information from power domains in it. This
> is well suited for configuration 1 above.
> 
> But for configuration 2 above, the root domain will present the same
> information as present by power domain. So, no use of aggregating. To
> check the configuration, call topology_max_dies_per_package(). If it is
> more than one, avoid creating root domain.
> 
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> ---
> This is a forward looking change as TPMI is architectural and should
> support all topologies.

Thank you for your patch, I've applied this patch to my review-hans 
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans



> 
> v2
> Updated commit description as suggested.
> 
>  .../x86/intel/uncore-frequency/uncore-frequency-tpmi.c     | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c
> index 2016acf44f6a..e6047fbbea76 100644
> --- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c
> +++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-tpmi.c
> @@ -557,6 +557,9 @@ static int uncore_probe(struct auxiliary_device *auxdev, const struct auxiliary_
>  
>  	auxiliary_set_drvdata(auxdev, tpmi_uncore);
>  
> +	if (topology_max_dies_per_package() > 1)
> +		return 0;
> +
>  	tpmi_uncore->root_cluster.root_domain = true;
>  	tpmi_uncore->root_cluster.uncore_root = tpmi_uncore;
>  
> @@ -580,7 +583,9 @@ static void uncore_remove(struct auxiliary_device *auxdev)
>  {
>  	struct tpmi_uncore_struct *tpmi_uncore = auxiliary_get_drvdata(auxdev);
>  
> -	uncore_freq_remove_die_entry(&tpmi_uncore->root_cluster.uncore_data);
> +	if (tpmi_uncore->root_cluster.root_domain)
> +		uncore_freq_remove_die_entry(&tpmi_uncore->root_cluster.uncore_data);
> +
>  	remove_cluster_entries(tpmi_uncore);
>  
>  	uncore_freq_common_exit();