linux-kernel - Re: [PATCH v2] platform/x86: amd-pmc: Export Idlemask values based on the APU

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Date:   Thu, 16 Sep 2021 18:30:49 +0530
From:   Shyam Sundar S K <Shyam-sundar.S-k@....com>
To:     Sanket Goswami <Sanket.Goswami@....com>, hdegoede@...hat.com,
        mgross@...ux.intel.com
Cc:     platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
        "Limonciello, Mario" <Mario.Limonciello@....com>
Subject: Re: [PATCH v2] platform/x86: amd-pmc: Export Idlemask values based on
 the APU

+Mario

On 9/16/2021 6:10 PM, Sanket Goswami wrote:
> IdleMask is the metric used by the PM firmware to know the status of each
> of the Hardware IP blocks monitored by the PM firmware.
> 
> Knowing this value is key to get the information of s2idle suspend/resume
> status. This value is mapped to PMC scratch registers, retrieve them
> accordingly based on the CPU family and the underlying firmware support.
> 
> Co-developed-by: Shyam Sundar S K <Shyam-sundar.S-k@....com>
> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@....com>
> Signed-off-by: Sanket Goswami <Sanket.Goswami@....com>
> ---
> Changes in v2:
> - Add separate routine amd_pmc_idlemask_read to get the value.
> - Address review comments from Mario.
> 
>  drivers/platform/x86/amd-pmc.c | 76 ++++++++++++++++++++++++++++++++++
>  1 file changed, 76 insertions(+)
> 
> diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c
> index 3481479a2942..0c970f613e09 100644
> --- a/drivers/platform/x86/amd-pmc.c
> +++ b/drivers/platform/x86/amd-pmc.c
> @@ -29,6 +29,10 @@
>  #define AMD_PMC_REGISTER_RESPONSE	0x980
>  #define AMD_PMC_REGISTER_ARGUMENT	0x9BC
>  
> +/* PMC Scratch Registers */
> +#define AMD_PMC_SCRATCH_REG_CZN		0x94
> +#define AMD_PMC_SCRATCH_REG_YC		0xD14
> +
>  /* Base address of SMU for mapping physical address to virtual address */
>  #define AMD_PMC_SMU_INDEX_ADDRESS	0xB8
>  #define AMD_PMC_SMU_INDEX_DATA		0xBC
> @@ -110,6 +114,10 @@ struct amd_pmc_dev {
>  	u32 base_addr;
>  	u32 cpu_id;
>  	u32 active_ips;
> +/* SMU version information */
> +	u16 major;
> +	u16 minor;
> +	u16 rev;
>  	struct device *dev;
>  	struct mutex lock; /* generic mutex lock */
>  #if IS_ENABLED(CONFIG_DEBUG_FS)
> @@ -201,6 +209,66 @@ static int s0ix_stats_show(struct seq_file *s, void *unused)
>  }
>  DEFINE_SHOW_ATTRIBUTE(s0ix_stats);
>  
> +static int amd_pmc_get_smu_version(struct amd_pmc_dev *dev)
> +{
> +	int rc;
> +	u32 val;
> +
> +	rc = amd_pmc_send_cmd(dev, 0, &val, SMU_MSG_GETSMUVERSION, 1);
> +	if (rc)
> +		return rc;
> +
> +	dev->major = (val >> 16) & GENMASK(15, 0);
> +	dev->minor = (val >> 8) & GENMASK(7, 0);
> +	dev->rev = (val >> 0) & GENMASK(7, 0);
> +
> +	dev_dbg(dev->dev, "SMU version is %u.%u.%u\n", dev->major, dev->minor, dev->rev);
> +
> +	return 0;
> +}
> +
> +static int amd_pmc_idlemask_read(struct amd_pmc_dev *pdev, struct device *dev,
> +				 struct seq_file *s)
> +{
> +	u32 val;
> +
> +	switch (pdev->cpu_id) {
> +	case AMD_CPU_ID_CZN:
> +		val = amd_pmc_reg_read(pdev, AMD_PMC_SCRATCH_REG_CZN);
> +		break;
> +	case AMD_CPU_ID_YC:
> +		val = amd_pmc_reg_read(pdev, AMD_PMC_SCRATCH_REG_YC);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (dev)
> +		dev_dbg(pdev->dev, "SMU idlemask s0i3: 0x%x\n", val);
> +
> +	if (s)
> +		seq_printf(s, "SMU idlemask : 0x%x\n", val);
> +
> +	return 0;
> +}
> +
> +static int amd_pmc_idlemask_show(struct seq_file *s, void *unused)
> +{
> +	struct amd_pmc_dev *dev = s->private;
> +	int rc;
> +
> +	if (dev->major > 56 || (dev->major >= 55 && dev->minor >= 37)) {
> +		rc = amd_pmc_idlemask_read(dev, NULL, s);
> +		if (rc)
> +			return rc;
> +	} else {
> +		seq_puts(s, "Unsupported SMU version for Idlemask\n");
> +	}
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(amd_pmc_idlemask);
> +
>  static void amd_pmc_dbgfs_unregister(struct amd_pmc_dev *dev)
>  {
>  	debugfs_remove_recursive(dev->dbgfs_dir);
> @@ -213,6 +281,8 @@ static void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
>  			    &smu_fw_info_fops);
>  	debugfs_create_file("s0ix_stats", 0644, dev->dbgfs_dir, dev,
>  			    &s0ix_stats_fops);
> +	debugfs_create_file("amd_pmc_idlemask", 0644, dev->dbgfs_dir, dev,
> +			    &amd_pmc_idlemask_fops);
>  }
>  #else
>  static inline void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
> @@ -349,6 +419,8 @@ static int __maybe_unused amd_pmc_suspend(struct device *dev)
>  	amd_pmc_send_cmd(pdev, 0, NULL, SMU_MSG_LOG_RESET, 0);
>  	amd_pmc_send_cmd(pdev, 0, NULL, SMU_MSG_LOG_START, 0);
>  
> +	/* Dump the IdleMask before we send hint to SMU */
> +	amd_pmc_idlemask_read(pdev, dev, NULL);
>  	msg = amd_pmc_get_os_hint(pdev);
>  	rc = amd_pmc_send_cmd(pdev, 1, NULL, msg, 0);
>  	if (rc)
> @@ -371,6 +443,9 @@ static int __maybe_unused amd_pmc_resume(struct device *dev)
>  	if (rc)
>  		dev_err(pdev->dev, "resume failed\n");
>  
> +	/* Dump the IdleMask to see the blockers */
> +	amd_pmc_idlemask_read(pdev, dev, NULL);
> +
>  	return 0;
>  }
>  
> @@ -457,6 +532,7 @@ static int amd_pmc_probe(struct platform_device *pdev)
>  	if (err)
>  		dev_err(dev->dev, "SMU debugging info not supported on this platform\n");
>  
> +	amd_pmc_get_smu_version(dev);
>  	platform_set_drvdata(pdev, dev);
>  	amd_pmc_dbgfs_register(dev);
>  	return 0;
> 

Looks good to me.

Acked-by: Shyam Sundar S K <Shyam-sundar.S-k@....com>