Re: [PATCH v3 14/14] platform/x86: hfi: Add debugfs support

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Tue, 15 Oct 2024, Mario Limonciello wrote:

> Add a dump of the class and capabilities table to debugfs to assist
> with debugging scheduler issues.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v2->v3:
>   * New patch
> ---
>  drivers/platform/x86/amd/hfi/hfi.c | 31 ++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/drivers/platform/x86/amd/hfi/hfi.c b/drivers/platform/x86/amd/hfi/hfi.c
> index 6c90b50f0a40..6df80f6ac73c 100644
> --- a/drivers/platform/x86/amd/hfi/hfi.c
> +++ b/drivers/platform/x86/amd/hfi/hfi.c
> @@ -13,6 +13,7 @@
>  #include <linux/acpi.h>
>  #include <linux/cpu.h>
>  #include <linux/cpumask.h>
> +#include <linux/debugfs.h>
>  #include <linux/gfp.h>
>  #include <linux/init.h>
>  #include <linux/io.h>
> @@ -79,6 +80,8 @@ struct amd_hfi_data {
>  	void __iomem		*pcc_comm_addr;
>  	struct acpi_subtable_header	*pcct_entry;
>  	struct amd_shmem_info	*shmem;
> +
> +	struct dentry *dbgfs_dir;
>  };
>  
>  /**
> @@ -243,6 +246,8 @@ static void amd_hfi_remove(struct platform_device *pdev)
>  {
>  	struct amd_hfi_data *dev = platform_get_drvdata(pdev);
>  
> +	debugfs_remove_recursive(dev->dbgfs_dir);
> +
>  	mutex_destroy(&dev->lock);
>  }
>  
> @@ -400,6 +405,28 @@ static int amd_hfi_metadata_parser(struct platform_device *pdev,
>  	return ret;
>  }
>  
> +static int class_capabilities_show(struct seq_file *s, void *unused)
> +{
> +	int cpu, idx;
> +
> +	seq_puts(s, "CPU #\tWLC\tPerf\tEff\n");
> +	for_each_present_cpu(cpu) {
> +		struct amd_hfi_cpuinfo *hfi_cpuinfo = per_cpu_ptr(&amd_hfi_cpuinfo, cpu);
> +
> +		seq_printf(s, "%d\t", cpu);
> +		for (idx = 0; idx < hfi_cpuinfo->nr_class; idx++) {
> +			seq_printf(s, "%s%d\t%d\t%d\n",
> +				   idx == 0 ? "" : "\t",

Is this conditional printing really required? Why cannot you just print \t 
always here and remove it from the cpu print line?

-- 
 i.

> +				   idx,
> +				   hfi_cpuinfo->amd_hfi_classes[idx].perf,
> +				   hfi_cpuinfo->amd_hfi_classes[idx].eff);
> +		}
> +	}
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(class_capabilities);
> +
>  static int amd_hfi_pm_resume(struct device *dev)
>  {
>  	int ret, cpu;
> @@ -473,6 +500,10 @@ static int amd_hfi_probe(struct platform_device *pdev)
>  
>  	schedule_work(&sched_amd_hfi_itmt_work);
>  
> +	amd_hfi_data->dbgfs_dir = debugfs_create_dir("amd_hfi", arch_debugfs_dir);
> +	debugfs_create_file("class_capabilities", 0644, amd_hfi_data->dbgfs_dir, pdev,
> +			    &class_capabilities_fops);
> +
>  	return 0;
>  }
>  
>