David Miller wrote: [Tue Sep 16 2014, 09:48:03PM EDT] > From: Bob Picco <bpicco@xxxxxxxxxx> > Date: Tue, 16 Sep 2014 12:50:39 -0400 > > > From: bob picco <bpicco@xxxxxxxxxx> > > > > For physical address larger than 47 bits the computed physical address > > was insufficient within KERN_TSB_LOOKUP_TL1. This resulted in a vmlinux > > loaded above 47 bits of physical address unable to boot in spectacular > > ways. > > > > For now we've expanded the physical address range to 52 bits at the cost of > > two instructions. Older sparc64 incur two nop-s. > > > > The two new instructions from this patch and the former KTSB_PHYS_SHIFT can > > potentially be eliminated using memblock aligning large and constraining > > the physical limit. Essentially use the "sethi" for a physical manipulated > > address and replacing the "or" at patch time with a "sllx". This would leave > > the tsb within head_64.S unused and possibly not a good solution for Cheetah+. > > We'll comtemplate this more in another round. > > > > Cc: sparclinux@xxxxxxxxxxxxxxx > > Signed-off-by: Bob Picco <bob.picco@xxxxxxxxxx> > > Bob, thanks for doing this work to support up to 49-bits of physical > addressing. You are very welcome. > > There are a lot of tradeoffs and thorny issues involved here, so I'm > going to take some time reviewing this set of patches. Indeed many tricky issues. I took a first stab at it. > > I'll try to get back to you on these changes in a reasonable amount of > time, thanks for your patience. No hurry and thanx. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
