[Skiboot] [PATCH 1/2] hmi: refactor malfunction alert handling

[Mahesh Jagannath Salgaonkar]

On 03/01/2017 05:28 AM, Andrew Donnellan wrote:
> The logic in decode_malfunction() is rather tricky to follow. Refactor the
> code to make it easier to follow.
> 
> No functional change.
> 
> Cc: Russell Currey <ruscur at russell.cc>
> Cc: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>
> Cc: Ryan Grimm <grimm at linux.vnet.ibm.com>
> Cc: Frederic Barrat <fbarrat at linux.vnet.ibm.com>
> Cc: Daniel Axtens <dja at axtens.net>
> Signed-off-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>

Looks good to me.

Reviewed-by: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>

> 
> ---
> 
> I'd appreciate review here, I hope I haven't introduced any unintended
> changes, but I also don't think I fully understand the expected behaviour.
> I've given it some limited testing, it doesn't seem to break my CAPI kexec
> series which is good.
> ---
>  core/hmi.c | 88 ++++++++++++++++++++++++++++++--------------------------------
>  1 file changed, 42 insertions(+), 46 deletions(-)
> 
> diff --git a/core/hmi.c b/core/hmi.c
> index 6fe060dc..31a23ec7 100644
> --- a/core/hmi.c
> +++ b/core/hmi.c
> @@ -296,27 +296,6 @@ static int handle_capp_recoverable(int chip_id, int capp_index)
>  	return 0;
>  }
> 
> -static int decode_one_malfunction(int flat_chip_id, struct OpalHMIEvent *hmi_evt)
> -{
> -	int capp_index;
> -	struct proc_chip *chip = get_chip(flat_chip_id);
> -	int capp_num = CHIP_IS_NAPLES(chip) ? 2 : 1;
> -
> -	hmi_evt->severity = OpalHMI_SEV_FATAL;
> -	hmi_evt->type = OpalHMI_ERROR_MALFUNC_ALERT;
> -
> -	for (capp_index = 0; capp_index < capp_num; capp_index++)
> -		if (is_capp_recoverable(flat_chip_id, capp_index))
> -			if (handle_capp_recoverable(flat_chip_id, capp_index)) {
> -				hmi_evt->severity = OpalHMI_SEV_NO_ERROR;
> -				hmi_evt->type = OpalHMI_ERROR_CAPP_RECOVERY;
> -				return 1;
> -			}
> -
> -	/* TODO check other FIRs */
> -	return 0;
> -}
> -
>  static bool decode_core_fir(struct cpu_thread *cpu,
>  				struct OpalHMIEvent *hmi_evt)
>  {
> @@ -368,7 +347,7 @@ static bool decode_core_fir(struct cpu_thread *cpu,
>  }
> 
>  static void find_core_checkstop_reason(struct OpalHMIEvent *hmi_evt,
> -					int *event_generated)
> +				       bool *event_generated)
>  {
>  	struct cpu_thread *cpu;
> 
> @@ -401,8 +380,30 @@ static void find_core_checkstop_reason(struct OpalHMIEvent *hmi_evt,
>  	}
>  }
> 
> +static void find_capp_checkstop_reason(int flat_chip_id,
> +				       struct OpalHMIEvent *hmi_evt,
> +				       bool *event_generated)
> +{
> +	int capp_index;
> +	struct proc_chip *chip = get_chip(flat_chip_id);
> +	int capp_num = CHIP_IS_NAPLES(chip) ? 2 : 1;
> +
> +	for (capp_index = 0; capp_index < capp_num; capp_index++) {
> +		if (is_capp_recoverable(flat_chip_id, capp_index)) {
> +			if (handle_capp_recoverable(flat_chip_id, capp_index)) {
> +				hmi_evt->severity = OpalHMI_SEV_NO_ERROR;
> +				hmi_evt->type = OpalHMI_ERROR_CAPP_RECOVERY;
> +				queue_hmi_event(hmi_evt, 1);
> +				*event_generated = true;
> +				return;
> +			}
> +		}
> +	}
> +}
> +
>  static void find_nx_checkstop_reason(int flat_chip_id,
> -			struct OpalHMIEvent *hmi_evt, int *event_generated)
> +				     struct OpalHMIEvent *hmi_evt,
> +				     bool *event_generated)
>  {
>  	uint64_t nx_status;
>  	uint64_t nx_dma_fir;
> @@ -461,12 +462,12 @@ static void find_nx_checkstop_reason(int flat_chip_id,
> 
>  	/* Send an HMI event. */
>  	queue_hmi_event(hmi_evt, 0);
> -	*event_generated = 1;
> +	*event_generated = true;
>  }
> 
>  static void find_npu_checkstop_reason(int flat_chip_id,
>  				      struct OpalHMIEvent *hmi_evt,
> -				      int *event_generated)
> +				      bool *event_generated)
>  {
>  	struct phb *phb;
>  	struct npu *p = NULL;
> @@ -530,43 +531,38 @@ static void find_npu_checkstop_reason(int flat_chip_id,
> 
>  	/* The HMI is "recoverable" because it shouldn't crash the system */
>  	queue_hmi_event(hmi_evt, 1);
> -	*event_generated = 1;
> +	*event_generated = true;
>  }
> 
>  static void decode_malfunction(struct OpalHMIEvent *hmi_evt)
>  {
>  	int i;
> -	int recover = -1;
>  	uint64_t malf_alert;
> -	int event_generated = 0;
> +	bool event_generated = false;
> 
>  	xscom_read(this_cpu()->chip_id, 0x2020011, &malf_alert);
> 
> -	for (i = 0; i < 64; i++)
> +	if (!malf_alert)
> +		return;
> +
> +	for (i = 0; i < 64; i++) {
>  		if (malf_alert & PPC_BIT(i)) {
> -			recover = decode_one_malfunction(i, hmi_evt);
>  			xscom_write(this_cpu()->chip_id, 0x02020011, ~PPC_BIT(i));
> -			if (recover) {
> -				queue_hmi_event(hmi_evt, recover);
> -				event_generated = 1;
> -			}
> +			find_capp_checkstop_reason(i, hmi_evt, &event_generated);
>  			find_nx_checkstop_reason(i, hmi_evt, &event_generated);
>  			find_npu_checkstop_reason(i, hmi_evt, &event_generated);
>  		}
> +	}
> 
> -	if (recover != -1) {
> -		find_core_checkstop_reason(hmi_evt, &event_generated);
> +	find_core_checkstop_reason(hmi_evt, &event_generated);
> 
> -		/*
> -		 * In case, if we fail to find checkstop reason send an
> -		 * unknown HMI event.
> -		 */
> -		if (!event_generated) {
> -			hmi_evt->u.xstop_error.xstop_type =
> -						CHECKSTOP_TYPE_UNKNOWN;
> -			hmi_evt->u.xstop_error.xstop_reason = 0;
> -			queue_hmi_event(hmi_evt, recover);
> -		}
> +	/*
> +	 * If we fail to find checkstop reason, send an unknown HMI event.
> +	 */
> +	if (!event_generated) {
> +		hmi_evt->u.xstop_error.xstop_type = CHECKSTOP_TYPE_UNKNOWN;
> +		hmi_evt->u.xstop_error.xstop_reason = 0;
> +		queue_hmi_event(hmi_evt, false);
>  	}
>  }
>