Re: [PATCH v3 05/11] platform/x86/amd/pmf: Add heartbeat signal support

[Shyam Sundar S K <Shyam-sundar.S-k@amd.com>]

Hi Hans,

On 8/2/2022 6:22 PM, Hans de Goede wrote:
> Hi,
> 
> On 8/2/22 13:25, Shyam Sundar S K wrote:
>> PMF driver can send periodic heartbeat signals to OEM BIOS. When BIOS does
>> not receive the signal after a period of time, it can infer that AMDPMF
>> has hung or failed to load.
>>
>> In this situation, BIOS can fallback to legacy operations. OEM can modify
>> the time interval of the signal or completely disable signals through
>> ACPI Method.
>>
>> Reviewed-by: Hans de Goede <hdegoede@redhat.com>
>> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
>> ---
>>  drivers/platform/x86/amd/pmf/acpi.c | 37 +++++++++++++++++++++++++++--
>>  drivers/platform/x86/amd/pmf/core.c |  1 +
>>  drivers/platform/x86/amd/pmf/pmf.h  |  5 ++++
>>  3 files changed, 41 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/platform/x86/amd/pmf/acpi.c b/drivers/platform/x86/amd/pmf/acpi.c
>> index 717ee81a5f73..c3f87265eeae 100644
>> --- a/drivers/platform/x86/amd/pmf/acpi.c
>> +++ b/drivers/platform/x86/amd/pmf/acpi.c
>> @@ -105,6 +105,25 @@ int apmf_get_static_slider_granular(struct amd_pmf_dev *pdev,
>>  									 data, sizeof(*data));
>>  }
>>  
>> +static void apmf_sbios_heartbeat_notify(struct work_struct *work)
>> +{
>> +	struct amd_pmf_dev *dev = container_of(work, struct amd_pmf_dev, heart_beat.work);
>> +	union acpi_object *info;
>> +	int err = 0;
>> +
>> +	dev_dbg(dev->dev, "Sending heartbeat to SBIOS\n");
>> +	info = apmf_if_call(dev, APMF_FUNC_SBIOS_HEARTBEAT, NULL);
>> +	if (!info) {
>> +		err = -EIO;
> 
> I did not notice this before, but err gets set here and then never used.
> 
> Maybe instead log an error when the call fails ?
> 
> Also the work is not re-queued on an error here, I assume this is on
> purpose ?

Yes, that's right. We should not re-queue if the call fails and leave
the control for legacy operations.

Thanks,
Shyam

> 
> Regards,
> 
> Hans
> 
> 
>> +		goto out;
>> +	}
>> +
>> +	schedule_delayed_work(&dev->heart_beat, msecs_to_jiffies(dev->hb_interval * 1000));
>> +
>> +out:
>> +	kfree(info);
>> +}
>> +
>>  static int apmf_if_verify_interface(struct amd_pmf_dev *pdev)
>>  {
>>  	struct apmf_verify_interface output;
>> @@ -133,15 +152,23 @@ static int apmf_get_system_params(struct amd_pmf_dev *dev)
>>  	if (err)
>>  		return err;
>>  
>> -	dev_dbg(dev->dev, "system params mask:0x%x flags:0x%x cmd_code:0x%x\n",
>> +	dev_dbg(dev->dev, "system params mask:0x%x flags:0x%x cmd_code:0x%x heartbeat:%d\n",
>>  		params.valid_mask,
>>  		params.flags,
>> -		params.command_code);
>> +		params.command_code,
>> +		params.heartbeat_int);
>>  	params.flags = params.flags & params.valid_mask;
>> +	dev->hb_interval = params.heartbeat_int;
>>  
>>  	return 0;
>>  }
>>  
>> +void apmf_acpi_deinit(struct amd_pmf_dev *pmf_dev)
>> +{
>> +	if (pmf_dev->hb_interval)
>> +		cancel_delayed_work_sync(&pmf_dev->heart_beat);
>> +}
>> +
>>  int apmf_acpi_init(struct amd_pmf_dev *pmf_dev)
>>  {
>>  	int ret;
>> @@ -158,6 +185,12 @@ int apmf_acpi_init(struct amd_pmf_dev *pmf_dev)
>>  		goto out;
>>  	}
>>  
>> +	if (pmf_dev->hb_interval) {
>> +		/* send heartbeats only if the interval is not zero */
>> +		INIT_DELAYED_WORK(&pmf_dev->heart_beat, apmf_sbios_heartbeat_notify);
>> +		schedule_delayed_work(&pmf_dev->heart_beat, 0);
>> +	}
>> +
>>  out:
>>  	return ret;
>>  }
>> diff --git a/drivers/platform/x86/amd/pmf/core.c b/drivers/platform/x86/amd/pmf/core.c
>> index 032d9dc5e09f..87a1f9b27d2c 100644
>> --- a/drivers/platform/x86/amd/pmf/core.c
>> +++ b/drivers/platform/x86/amd/pmf/core.c
>> @@ -279,6 +279,7 @@ static int amd_pmf_remove(struct platform_device *pdev)
>>  
>>  	mutex_destroy(&dev->lock);
>>  	amd_pmf_deinit_features(dev);
>> +	apmf_acpi_deinit(dev);
>>  	amd_pmf_dbgfs_unregister(dev);
>>  	kfree(dev->buf);
>>  	return 0;
>> diff --git a/drivers/platform/x86/amd/pmf/pmf.h b/drivers/platform/x86/amd/pmf/pmf.h
>> index e13542359403..5b85a7fe0f38 100644
>> --- a/drivers/platform/x86/amd/pmf/pmf.h
>> +++ b/drivers/platform/x86/amd/pmf/pmf.h
>> @@ -17,6 +17,7 @@
>>  /* APMF Functions */
>>  #define APMF_FUNC_VERIFY_INTERFACE			0
>>  #define APMF_FUNC_GET_SYS_PARAMS			1
>> +#define APMF_FUNC_SBIOS_HEARTBEAT			4
>>  #define APMF_FUNC_STATIC_SLIDER_GRANULAR       9
>>  
>>  /* Message Definitions */
>> @@ -53,6 +54,7 @@ struct apmf_system_params {
>>  	u32 valid_mask;
>>  	u32 flags;
>>  	u8 command_code;
>> +	u32 heartbeat_int;
>>  } __packed;
>>  
>>  enum amd_stt_skin_temp {
>> @@ -91,6 +93,8 @@ struct amd_pmf_dev {
>>  	enum platform_profile_option current_profile;
>>  	struct platform_profile_handler pprof;
>>  	struct dentry *dbgfs_dir;
>> +	int hb_interval; /* SBIOS heartbeat interval */
>> +	struct delayed_work heart_beat;
>>  };
>>  
>>  struct apmf_sps_prop_granular {
>> @@ -116,6 +120,7 @@ struct amd_pmf_static_slider_granular {
>>  
>>  /* Core Layer */
>>  int apmf_acpi_init(struct amd_pmf_dev *pmf_dev);
>> +void apmf_acpi_deinit(struct amd_pmf_dev *pmf_dev);
>>  int is_apmf_func_supported(struct amd_pmf_dev *pdev, unsigned long index);
>>  int amd_pmf_send_cmd(struct amd_pmf_dev *dev, u8 message, bool get, u32 arg, u32 *data);
>>  int amd_pmf_get_power_source(void);
>