* [PATCH 1/1] ipr: add writeq definition if needed [not found] <20100608224308.499532262@linux.vnet.ibm.com> @ 2010-06-09 15:24 ` Wayne Boyer 2010-06-09 16:04 ` Brian King 2010-06-09 16:20 ` James Bottomley 0 siblings, 2 replies; 5+ messages in thread From: Wayne Boyer @ 2010-06-09 15:24 UTC (permalink / raw) To: ben, James Bottomley; +Cc: linux-scsi, Brian King Compiling the driver will fail on 32 bit powerpc and other architectures where writeq is not defined. This patch adds a definition for writeq. Signed-off-by: Wayne Boyer <wayneb@linux.vnet.ibm.com> --- drivers/scsi/ipr.h | 8 ++++++++ 1 file changed, 8 insertions(+) Index: b/drivers/scsi/ipr.h =================================================================== --- a/drivers/scsi/ipr.h 2010-06-08 10:06:48.000000000 -0700 +++ b/drivers/scsi/ipr.h 2010-06-08 15:14:42.000000000 -0700 @@ -1860,4 +1860,12 @@ static inline int ipr_sdt_is_fmt2(u32 sd return 0; } +#ifndef writeq +static inline void writeq(u64 val, void __iomem *addr) +{ + writel(((u32) (val >> 32)), addr); + writel(((u32) (val)), (addr + 4)); +} #endif + +#endif /* _IPR_H */ ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 1/1] ipr: add writeq definition if needed 2010-06-09 15:24 ` [PATCH 1/1] ipr: add writeq definition if needed Wayne Boyer @ 2010-06-09 16:04 ` Brian King 2010-06-09 16:20 ` James Bottomley 1 sibling, 0 replies; 5+ messages in thread From: Brian King @ 2010-06-09 16:04 UTC (permalink / raw) To: Wayne Boyer; +Cc: ben, James Bottomley, linux-scsi Acked-by: Brian King <brking@linux.vnet.ibm.com> On 06/09/2010 10:24 AM, Wayne Boyer wrote: > Compiling the driver will fail on 32 bit powerpc and other > architectures where writeq is not defined. This patch adds a > definition for writeq. > > Signed-off-by: Wayne Boyer <wayneb@linux.vnet.ibm.com> > --- > > drivers/scsi/ipr.h | 8 ++++++++ > 1 file changed, 8 insertions(+) > > Index: b/drivers/scsi/ipr.h > =================================================================== > --- a/drivers/scsi/ipr.h 2010-06-08 10:06:48.000000000 -0700 > +++ b/drivers/scsi/ipr.h 2010-06-08 15:14:42.000000000 -0700 > @@ -1860,4 +1860,12 @@ static inline int ipr_sdt_is_fmt2(u32 sd > return 0; > } > > +#ifndef writeq > +static inline void writeq(u64 val, void __iomem *addr) > +{ > + writel(((u32) (val >> 32)), addr); > + writel(((u32) (val)), (addr + 4)); > +} > #endif > + > +#endif /* _IPR_H */ > -- Brian King Linux on Power Virtualization IBM Linux Technology Center ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 1/1] ipr: add writeq definition if needed 2010-06-09 15:24 ` [PATCH 1/1] ipr: add writeq definition if needed Wayne Boyer 2010-06-09 16:04 ` Brian King @ 2010-06-09 16:20 ` James Bottomley 2010-06-09 17:45 ` Wayne Boyer 1 sibling, 1 reply; 5+ messages in thread From: James Bottomley @ 2010-06-09 16:20 UTC (permalink / raw) To: Wayne Boyer; +Cc: ben, linux-scsi, Brian King On Wed, 2010-06-09 at 08:24 -0700, Wayne Boyer wrote: > Compiling the driver will fail on 32 bit powerpc and other > architectures where writeq is not defined. This patch adds a > definition for writeq. > > Signed-off-by: Wayne Boyer <wayneb@linux.vnet.ibm.com> > --- > > drivers/scsi/ipr.h | 8 ++++++++ > 1 file changed, 8 insertions(+) > > Index: b/drivers/scsi/ipr.h > =================================================================== > --- a/drivers/scsi/ipr.h 2010-06-08 10:06:48.000000000 -0700 > +++ b/drivers/scsi/ipr.h 2010-06-08 15:14:42.000000000 -0700 > @@ -1860,4 +1860,12 @@ static inline int ipr_sdt_is_fmt2(u32 sd > return 0; > } > > +#ifndef writeq > +static inline void writeq(u64 val, void __iomem *addr) > +{ > + writel(((u32) (val >> 32)), addr); > + writel(((u32) (val)), (addr + 4)); Are you sure this is what you want? The point about writeq is to do an atomic write of a 64 bit quantity. Doing two writel's loses the atomicity (and can confuse some hardware if not done in the right order). If this code above works correctly, why bother with the writeq? James ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 1/1] ipr: add writeq definition if needed 2010-06-09 16:20 ` James Bottomley @ 2010-06-09 17:45 ` Wayne Boyer 2010-06-09 18:43 ` James Bottomley 0 siblings, 1 reply; 5+ messages in thread From: Wayne Boyer @ 2010-06-09 17:45 UTC (permalink / raw) To: James Bottomley; +Cc: ben, linux-scsi, Brian King On 06/09/2010 09:20 AM, James Bottomley wrote: > On Wed, 2010-06-09 at 08:24 -0700, Wayne Boyer wrote: >> Compiling the driver will fail on 32 bit powerpc and other >> architectures where writeq is not defined. This patch adds a >> definition for writeq. >> >> Signed-off-by: Wayne Boyer <wayneb@linux.vnet.ibm.com> >> --- >> >> drivers/scsi/ipr.h | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> Index: b/drivers/scsi/ipr.h >> =================================================================== >> --- a/drivers/scsi/ipr.h 2010-06-08 10:06:48.000000000 -0700 >> +++ b/drivers/scsi/ipr.h 2010-06-08 15:14:42.000000000 -0700 >> @@ -1860,4 +1860,12 @@ static inline int ipr_sdt_is_fmt2(u32 sd >> return 0; >> } >> >> +#ifndef writeq >> +static inline void writeq(u64 val, void __iomem *addr) >> +{ >> + writel(((u32) (val >> 32)), addr); >> + writel(((u32) (val)), (addr + 4)); > > Are you sure this is what you want? The point about writeq is to do an > atomic write of a 64 bit quantity. Doing two writel's loses the > atomicity (and can confuse some hardware if not done in the right > order). If this code above works correctly, why bother with the writeq? > We do want to issue 8 byte MMIO writes where we can for the new adapters for better performance. We want to use writeq on platforms that support it. I did test the driver using this define with the new hardware and it does work as expected. -- Wayne Boyer IBM - Beaverton, Oregon LTC S/W Development - eServerIO (503) 578-5236, T/L 775-5236 ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 1/1] ipr: add writeq definition if needed 2010-06-09 17:45 ` Wayne Boyer @ 2010-06-09 18:43 ` James Bottomley 0 siblings, 0 replies; 5+ messages in thread From: James Bottomley @ 2010-06-09 18:43 UTC (permalink / raw) To: Wayne Boyer; +Cc: ben, linux-scsi, Brian King On Wed, 2010-06-09 at 10:45 -0700, Wayne Boyer wrote: > On 06/09/2010 09:20 AM, James Bottomley wrote: > > On Wed, 2010-06-09 at 08:24 -0700, Wayne Boyer wrote: > >> Compiling the driver will fail on 32 bit powerpc and other > >> architectures where writeq is not defined. This patch adds a > >> definition for writeq. > >> > >> Signed-off-by: Wayne Boyer <wayneb@linux.vnet.ibm.com> > >> --- > >> > >> drivers/scsi/ipr.h | 8 ++++++++ > >> 1 file changed, 8 insertions(+) > >> > >> Index: b/drivers/scsi/ipr.h > >> =================================================================== > >> --- a/drivers/scsi/ipr.h 2010-06-08 10:06:48.000000000 -0700 > >> +++ b/drivers/scsi/ipr.h 2010-06-08 15:14:42.000000000 -0700 > >> @@ -1860,4 +1860,12 @@ static inline int ipr_sdt_is_fmt2(u32 sd > >> return 0; > >> } > >> > >> +#ifndef writeq > >> +static inline void writeq(u64 val, void __iomem *addr) > >> +{ > >> + writel(((u32) (val >> 32)), addr); > >> + writel(((u32) (val)), (addr + 4)); > > > > Are you sure this is what you want? The point about writeq is to do an > > atomic write of a 64 bit quantity. Doing two writel's loses the > > atomicity (and can confuse some hardware if not done in the right > > order). If this code above works correctly, why bother with the writeq? > > > > We do want to issue 8 byte MMIO writes where we can for the new adapters > for better performance. We want to use writeq on platforms that support > it. I did test the driver using this define with the new hardware and it > does work as expected. OK, that's fine, just checking. I suppose we should have some type of writeq_nonatomic() so I don't have to check, but this is the first I've seen of these, so it's likely not very common. James ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2010-06-09 18:44 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <20100608224308.499532262@linux.vnet.ibm.com>
2010-06-09 15:24 ` [PATCH 1/1] ipr: add writeq definition if needed Wayne Boyer
2010-06-09 16:04 ` Brian King
2010-06-09 16:20 ` James Bottomley
2010-06-09 17:45 ` Wayne Boyer
2010-06-09 18:43 ` James Bottomley
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.