Subject: Re: [PATCH] powerpc/le: enable RTAS events support

From: Greg Kurz <[email-masked]>
Date: Fri, 28 Mar 2014 16:31:40 +0100

On Fri, 28 Mar 2014 09:57:03 -0500
Nathan Fontenot <[email-masked]> wrote:
> Greg,
> 
> There is one more place that needs fixing up, in mobility_rtas_call(),
> and handle_rtas_event() in arch/powerpc/platforms/pseries/mobility.c.
> 
> This relates to rtas event handling for PRRN notifications, we need to
> convert the scope variable (PRRN notifications re-use the extended log
> length field) when read from the rtas event in handle_rtas_event(), then
> convert it back to big endian in mobility_rtas_call().
> 
> The double conversion seems yucky but mobility_rtas_call can be called
> other places where the scope variable is not originally big endian.
> 
> -Nathan
> 

Nathan,

rtas_call() in arch/powerpc/kernel/rtas.c already does the conversion for us.

Thanks.

> On 03/28/2014 02:33 AM, Greg Kurz wrote:
> > The current kernel code assumes big endian and parses RTAS events all
> > wrong. The most visible effect is that we cannot honor EPOW events,
> > meaning, for example, we cannot shut down a guest properly from the
> > hypervisor.
> > 
> > This patch fixes that.
> > 
> > Signed-off-by: Greg Kurz <[email-masked]>
> > ---
> >  arch/powerpc/include/asm/rtas.h      |   46 ++++++++++++++++++++++++++++++++++
> >  arch/powerpc/kernel/rtas.c           |   11 ++++----
> >  arch/powerpc/kernel/rtasd.c          |    8 ++++--
> >  arch/powerpc/platforms/pseries/ras.c |    3 +-
> >  4 files changed, 59 insertions(+), 9 deletions(-)
> > 
> > diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
> > index 9bd52c6..8bb99d0 100644
> > --- a/arch/powerpc/include/asm/rtas.h
> > +++ b/arch/powerpc/include/asm/rtas.h
> > @@ -150,15 +150,37 @@ struct rtas_suspend_me_data {
> >  #define RTAS_VECTOR_EXTERNAL_INTERRUPT	0x500
> >  
> >  struct rtas_error_log {
> > +#ifdef __BIG_ENDIAN__
> > +	/* Byte 0 */
> >  	unsigned long version:8;		/* Architectural version */
> > +	/* Byte 1 */
> >  	unsigned long severity:3;		/* Severity level of error */
> >  	unsigned long disposition:2;		/* Degree of recovery */
> >  	unsigned long extended:1;		/* extended log present? */
> >  	unsigned long /* reserved */ :2;	/* Reserved for future use */
> > +	/* Byte 2 */
> >  	unsigned long initiator:4;		/* Initiator of event */
> >  	unsigned long target:4;			/* Target of failed operation */
> > +	/* Byte 3 */
> >  	unsigned long type:8;			/* General event or error*/
> > +	/* Byte 4 */
> >  	unsigned long extended_log_length:32;	/* length in bytes */
> > +#else
> > +	/* Byte 0 */
> > +	unsigned long version:8;
> > +	/* Byte 1 */
> > +	unsigned long :2;
> > +	unsigned long extended:1;
> > +	unsigned long disposition:2;
> > +	unsigned long severity:3;
> > +	unsigned long target:4;
> > +	/* Byte 2 */
> > +	unsigned long initiator:4;
> > +	/* Byte 3 */
> > +	unsigned long type:8;
> > +	/* Byte 4 */
> > +	unsigned long extended_log_length:32;
> > +#endif
> >  	unsigned char buffer[1];		/* Start of extended log */
> >  						/* Variable length.      */
> >  };
> > @@ -171,6 +193,7 @@ struct rtas_error_log {
> >   * from "buffer" field of struct rtas_error_log defined above.
> >   */
> >  struct rtas_ext_event_log_v6 {
> > +#ifdef __BIG_ENDIAN__
> >  	/* Byte 0 */
> >  	uint32_t log_valid:1;		/* 1:Log valid */
> >  	uint32_t unrecoverable_error:1;	/* 1:Unrecoverable error */
> > @@ -200,6 +223,29 @@ struct rtas_ext_event_log_v6 {
> >  	uint32_t company_id;		/* Company ID of the company	*/
> >  					/* that defines the format for	*/
> >  					/* the vendor specific log type	*/
> > +#else
> > +	/* Byte 0 */
> > +	uint32_t :1;
> > +	uint32_t big_endian:1;
> > +	uint32_t new_log:1;
> > +	uint32_t predictive_error:1;
> > +	uint32_t degraded_operation:1;
> > +	uint32_t recoverable_error:1;
> > +	uint32_t unrecoverable_error:1;
> > +	uint32_t log_valid:1;
> > +	/* Byte 1 */
> > +	uint32_t :8;
> > +	/* Byte 2 */
> > +	uint32_t log_format:4;
> > +	uint32_t :3;
> > +	uint32_t powerpc_format:1;
> > +	/* Byte 3 */
> > +	uint32_t :8;
> > +	/* Byte 4-11 */
> > +	uint8_t reserved[8];
> > +	/* Byte 12-15 */
> > +	uint32_t company_id;
> > +#endif
> >  	/* Byte 16-end of log */
> >  	uint8_t vendor_log[1];		/* Start of vendor specific log	*/
> >  					/* Variable length.		*/
> > diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
> > index f386296..e18ab12 100644
> > --- a/arch/powerpc/kernel/rtas.c
> > +++ b/arch/powerpc/kernel/rtas.c
> > @@ -993,21 +993,22 @@ struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
> >  		(struct rtas_ext_event_log_v6 *)log->buffer;
> >  	struct pseries_errorlog *sect;
> >  	unsigned char *p, *log_end;
> > +	uint32_t extended_log_length = be32_to_cpu(log->extended_log_length);
> >  
> >  	/* Check that we understand the format */
> > -	if (log->extended_log_length < sizeof(struct rtas_ext_event_log_v6) ||
> > +	if (extended_log_length < sizeof(struct rtas_ext_event_log_v6) ||
> >  	    ext_log->log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
> > -	    ext_log->company_id != RTAS_V6EXT_COMPANY_ID_IBM)
> > +	    be32_to_cpu(ext_log->company_id) != RTAS_V6EXT_COMPANY_ID_IBM)
> >  		return NULL;
> >  
> > -	log_end = log->buffer + log->extended_log_length;
> > +	log_end = log->buffer + extended_log_length;
> >  	p = ext_log->vendor_log;
> >  
> >  	while (p < log_end) {
> >  		sect = (struct pseries_errorlog *)p;
> > -		if (sect->id == section_id)
> > +		if (be16_to_cpu(sect->id) == section_id)
> >  			return sect;
> > -		p += sect->length;
> > +		p += be16_to_cpu(sect->length);
> >  	}
> >  
> >  	return NULL;
> > diff --git a/arch/powerpc/kernel/rtasd.c b/arch/powerpc/kernel/rtasd.c
> > index 1130c53..1987825 100644
> > --- a/arch/powerpc/kernel/rtasd.c
> > +++ b/arch/powerpc/kernel/rtasd.c
> > @@ -159,14 +159,16 @@ static int log_rtas_len(char * buf)
> >  {
> >  	int len;
> >  	struct rtas_error_log *err;
> > +	uint32_t extended_log_length;
> >  
> >  	/* rtas fixed header */
> >  	len = 8;
> >  	err = (struct rtas_error_log *)buf;
> > -	if (err->extended && err->extended_log_length) {
> > +	extended_log_length = be32_to_cpu(err->extended_log_length);
> > +	if (err->extended && extended_log_length) {
> >  
> >  		/* extended header */
> > -		len += err->extended_log_length;
> > +		len += extended_log_length;
> >  	}
> >  
> >  	if (rtas_error_log_max == 0)
> > @@ -298,7 +300,7 @@ static void handle_rtas_event(const struct rtas_error_log *log)
> >  		 * the scope for calling rtas update-nodes.
> >  		 */
> >  		if (prrn_is_enabled())
> > -			prrn_schedule_update(log->extended_log_length);
> > +			prrn_schedule_update(be32_to_cpu(log->extended_log_length));
> >  	}
> >  
> >  	return;
> > diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
> > index 721c058..39e7557 100644
> > --- a/arch/powerpc/platforms/pseries/ras.c
> > +++ b/arch/powerpc/platforms/pseries/ras.c
> > @@ -306,7 +306,8 @@ static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
> >  	} else {
> >  		int len;
> >  
> > -		len = max_t(int, 8+h->extended_log_length, RTAS_ERROR_LOG_MAX);
> > +		len = max_t(int, 8+be32_to_cpu(h->extended_log_length),
> > +			    RTAS_ERROR_LOG_MAX);
> >  		memset(global_mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
> >  		memcpy(global_mce_data_buf, h, len);
> >  		errhdr = (struct rtas_error_log *)global_mce_data_buf;
> > 
> > _______________________________________________
> > Linuxppc-dev mailing list
> > [email-masked]
> > https://lists.ozlabs.org/listinfo/linuxppc-dev
> > 

-- 
Gregory Kurz                                     [email-masked]
                                                 [email-masked]
Software Engineer @ IBM/Meiosys                  http://www.ibm.com
Tel +33 (0)562 165 496

"Anarchy is about taking complete responsibility for yourself."
        Alan Moore.