The 64 bit io operation on the IA64 platform is a 64 bit transaction on the pci bus and is optimal to leave it as such. I prefer Jeff's suggestion -
guaranteeing that a "good enough for drivers" readq() and writeq() exist on all platforms even 32-bit platforms where the operation isn't inherently atomic. Ram > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > On Behalf Of Benjamin Herrenschmidt > Sent: Monday, November 06, 2006 1:57 AM > To: Jeff Garzik > Cc: Linus Torvalds; netdev@vger.kernel.org > Subject: Re: [PATCH] s2io ppc64 fix for readq/writeq > > On Mon, 2006-11-06 at 04:55 -0500, Jeff Garzik wrote: > > Benjamin Herrenschmidt wrote: > > > On Mon, 2006-11-06 at 01:50 -0800, Linus Torvalds wrote: > > >> On Mon, 6 Nov 2006, Benjamin Herrenschmidt wrote: > > >>> Anyway, what do you think of Jeff proposal to just implement them as > two > > >>> 32 bits operations ? My arch guy side screams at the idea, but if, > > >>> indeed, drivers generally cope fine with it, I suppose that's ok. > > >> Last I saw, that's how normal PCI will split the IO anyway, so I > guess it > > >> makes sense. > > > > > > Hrm.. true indeed. I'll implement them that way for ppc32 then. > > > > Bonus points if you want to find-and-kill where individual drivers did > > > > #ifndef readq > > implement readq and writeq by hand... > > #endif > > Yes, well, we would have to make sure all archs have them defined > first though, but I suppose I can have a look later this week, maybe > tomorrow. Shouldn't be too hard :) > > Ben. > > > > - > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
