[PATCH V3 2/2] cpc925_edac: support single-processor configurations

[Dmitry Eremin-Solenikov]

On 6/29/11, Benjamin Herrenschmidt <benh at kernel.crashing.org> wrote:
> On Fri, 2011-06-17 at 16:51 +0400, Dmitry Eremin-Solenikov wrote:
>> If second CPU is not enabled, CPC925 EDAC driver will spill out warnings
>> about errors on second Processor Interface. Support masking that out,
>> by detecting at runtime which CPUs are present in device tree.
>
> Doug ? Are you going to carry this or should I via powerpc.git ? There's
> a dependency on another patch that's going into powerpc-next ...

I'm sorry. It's been a month ago. Is there any consensus regarding these two
patches? Are they going in in the 3.1 merge window?

>
> Cheers,
> Ben.
>
>> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov at gmail.com>
>> Cc: Harry Ciao <qingtao.cao at windriver.com>
>> Cc: Doug Thompson <dougthompson at xmission.com>
>> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov at gmail.com>
>> ---
>>  drivers/edac/cpc925_edac.c |   67
>> ++++++++++++++++++++++++++++++++++++++++++--
>>  1 files changed, 64 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/edac/cpc925_edac.c b/drivers/edac/cpc925_edac.c
>> index a687a0d..a774c0d 100644
>> --- a/drivers/edac/cpc925_edac.c
>> +++ b/drivers/edac/cpc925_edac.c
>> @@ -90,6 +90,7 @@ enum apimask_bits {
>>  	ECC_MASK_ENABLE = (APIMASK_ECC_UE_H | APIMASK_ECC_CE_H |
>>  			   APIMASK_ECC_UE_L | APIMASK_ECC_CE_L),
>>  };
>> +#define APIMASK_ADI(n)		CPC925_BIT(((n)+1))
>>
>>  /************************************************************
>>   *	Processor Interface Exception Register (APIEXCP)
>> @@ -581,16 +582,73 @@ static void cpc925_mc_check(struct mem_ctl_info
>> *mci)
>>  }
>>
>>  /******************** CPU err device********************************/
>> +static u32 cpc925_cpu_mask_disabled(void)
>> +{
>> +	struct device_node *cpus;
>> +	struct device_node *cpunode = NULL;
>> +	static u32 mask = 0;
>> +
>> +	/* use cached value if available */
>> +	if (mask != 0)
>> +		return mask;
>> +
>> +	mask = APIMASK_ADI0 | APIMASK_ADI1;
>> +
>> +	cpus = of_find_node_by_path("/cpus");
>> +	if (cpus == NULL) {
>> +		cpc925_printk(KERN_DEBUG, "No /cpus node !\n");
>> +		return 0;
>> +	}
>> +
>> +	while ((cpunode = of_get_next_child(cpus, cpunode)) != NULL) {
>> +		const u32 *reg = of_get_property(cpunode, "reg", NULL);
>> +
>> +		if (strcmp(cpunode->type, "cpu")) {
>> +			cpc925_printk(KERN_ERR, "Not a cpu node in /cpus: %s\n",
>> cpunode->name);
>> +			continue;
>> +		}
>> +
>> +		if (reg == NULL || *reg > 2) {
>> +			cpc925_printk(KERN_ERR, "Bad reg value at %s\n", cpunode->full_name);
>> +			continue;
>> +		}
>> +
>> +		mask &= ~APIMASK_ADI(*reg);
>> +	}
>> +
>> +	if (mask != (APIMASK_ADI0 | APIMASK_ADI1)) {
>> +		/* We assume that each CPU sits on it's own PI and that
>> +		 * for present CPUs the reg property equals to the PI
>> +		 * interface id */
>> +		cpc925_printk(KERN_WARNING,
>> +				"Assuming PI id is equal to CPU MPIC id!\n");
>> +	}
>> +
>> +	of_node_put(cpunode);
>> +	of_node_put(cpus);
>> +
>> +	return mask;
>> +}
>> +
>>  /* Enable CPU Errors detection */
>>  static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
>>  {
>>  	u32 apimask;
>> +	u32 cpumask;
>>
>>  	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
>> -	if ((apimask & CPU_MASK_ENABLE) == 0) {
>> -		apimask |= CPU_MASK_ENABLE;
>> -		__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
>> +
>> +	cpumask = cpc925_cpu_mask_disabled();
>> +	if (apimask & cpumask) {
>> +		cpc925_printk(KERN_WARNING, "CPU(s) not present, "
>> +				"but enabled in APIMASK, disabling\n");
>> +		apimask &= ~cpumask;
>>  	}
>> +
>> +	if ((apimask & CPU_MASK_ENABLE) == 0)
>> +		apimask |= CPU_MASK_ENABLE;
>> +
>> +	__raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
>>  }
>>
>>  /* Disable CPU Errors detection */
>> @@ -622,6 +680,9 @@ static void cpc925_cpu_check(struct
>> edac_device_ctl_info *edac_dev)
>>  	if ((apiexcp & CPU_EXCP_DETECTED) == 0)
>>  		return;
>>
>> +	if ((apiexcp & ~cpc925_cpu_mask_disabled()) == 0)
>> +		return;
>> +
>>  	apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
>>  	cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
>>  				 "Processor Interface register dump:\n");
>
>
>


-- 
With best wishes
Dmitry