Subject: Re: [PATCH 5/8] Read rtas partition via pstore

From: Aruna Balakrishnaiah <[email-masked]>
Date: Tue, 16 Apr 2013 11:51:42 +0530

On Monday 15 April 2013 01:31 PM, Michael Ellerman wrote:
> On Wed, Apr 10, 2013 at 12:53:27PM +0530, Aruna Balakrishnaiah wrote:
>> This patch exploits pstore infrastructure to read the details
>> from NVRAM's rtas partition.
> Does that mean it's exposed in the pstore filesystem?

Yeah thats right.

>> Signed-off-by: Aruna Balakrishnaiah <[email-masked]>
>> Reviewed-by: Jim Keniston <[email-masked]>
>> ---
>>   arch/powerpc/platforms/pseries/nvram.c |   33 +++++++++++++++++++++++++-------
>>   fs/pstore/inode.c                      |    3 +++
>>   include/linux/pstore.h                 |    2 ++
>>   3 files changed, 31 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
>> index 82d32a2..d420b1d 100644
>> --- a/arch/powerpc/platforms/pseries/nvram.c
>> +++ b/arch/powerpc/platforms/pseries/nvram.c
>> @@ -144,9 +144,11 @@ static size_t oops_data_sz;
>>   #ifdef CONFIG_PSTORE
>>   static enum pstore_type_id nvram_type_ids[] = {
>>   	PSTORE_TYPE_DMESG,
>> +	PSTORE_TYPE_RTAS,
>>   	-1
>>   };
>>   static int read_type;
>> +static unsigned long last_rtas_event;
>>   #endif
>>   /* Compression parameters */
>>   #define COMPR_LEVEL 6
>> @@ -315,8 +317,13 @@ int nvram_write_error_log(char * buff, int length,
>>   {
>>   	int rc = nvram_write_os_partition(&rtas_log_partition, buff, length,
>>   						err_type, error_log_cnt);
>> -	if (!rc)
>> +	if (!rc) {
>>   		last_unread_rtas_event = get_seconds();
>> +#ifdef CONFIG_PSTORE
>> +		last_rtas_event = get_seconds();
>> +#endif
>> +	}
>> +
>>   	return rc;
>>   }
>>   
>> @@ -745,7 +752,7 @@ static int nvram_pstore_write(enum pstore_type_id type,
>>   }
>>   
>>   /*
>> - * Reads the oops/panic report.
>> + * Reads the oops/panic report and ibm,rtas-log partition.
>>    * Returns the length of the data we read from each partition.
>>    * Returns 0 if we've been called before.
>>    */
>> @@ -765,6 +772,12 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
>>   		part = &oops_log_partition;
>>   		*type = PSTORE_TYPE_DMESG;
>>   		break;
>> +	case PSTORE_TYPE_RTAS:
>> +		part = &rtas_log_partition;
>> +		*type = PSTORE_TYPE_RTAS;
>> +		time->tv_sec = last_rtas_event;
>> +		time->tv_nsec = 0;
>> +		break;
>>   	default:
>>   		return 0;
>>   	}
>> @@ -781,11 +794,17 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
>>   
>>   	*count = 0;
>>   	*id = id_no;
>> -	oops_hdr = (struct oops_log_info *)buff;
>> -	*buf = buff + sizeof(*oops_hdr);
>> -	time->tv_sec = oops_hdr->timestamp;
>> -	time->tv_nsec = 0;
>> -	return oops_hdr->report_length;
>> +
>> +	if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
>> +		oops_hdr = (struct oops_log_info *)buff;
>> +		*buf = buff + sizeof(*oops_hdr);
>> +		time->tv_sec = oops_hdr->timestamp;
>> +		time->tv_nsec = 0;
>> +		return oops_hdr->report_length;
>> +	}
>> +
>> +	*buf = buff;
>> +	return part->size;
>>   }
>>   #else
>>   static int nvram_pstore_open(struct pstore_info *psi)
>> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
>> index e4bcb2c..59b1454 100644
>> --- a/fs/pstore/inode.c
>> +++ b/fs/pstore/inode.c
>> @@ -324,6 +324,9 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
>>   	case PSTORE_TYPE_MCE:
>>   		sprintf(name, "mce-%s-%lld", psname, id);
>>   		break;
>> +	case PSTORE_TYPE_RTAS:
>> +		sprintf(name, "rtas-%s-%lld", psname, id);
>> +		break;
>>   	case PSTORE_TYPE_UNKNOWN:
>>   		sprintf(name, "unknown-%s-%lld", psname, id);
>>   		break;
>> diff --git a/include/linux/pstore.h b/include/linux/pstore.h
>> index 75d0176..4eb94c9 100644
>> --- a/include/linux/pstore.h
>> +++ b/include/linux/pstore.h
>> @@ -35,6 +35,8 @@ enum pstore_type_id {
>>   	PSTORE_TYPE_MCE		= 1,
>>   	PSTORE_TYPE_CONSOLE	= 2,
>>   	PSTORE_TYPE_FTRACE	= 3,
>> +	/* PPC64 partition types */
>> +	PSTORE_TYPE_RTAS	= 10,
>>   	PSTORE_TYPE_UNKNOWN	= 255
> I think you should probably just continue at 4, and call it
> PSTORE_TYPE_PPC_RTAS. But you must get an ACK from the pstore
> maintainers for this and the previous hunk, and I don't see them on CC.

Sure, will add them on cc in my next version of the patches.

> cheers