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. There are a lot of tradeoffs and thorny issues involved here, so I'm going to take some time reviewing this set of patches. I'll try to get back to you on these changes in a reasonable amount of time, thanks for your patience. -- 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
