Hi Josh, On Wed, Sep 13, 2017 at 05:33:03PM -0500, Josh Poimboeuf wrote: > And here's v2 of the sha512-avx2 patch. It should hopefully gain back > most of the performance lost by v1. > > From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > Subject: [PATCH] x86/crypto: Fix RBP usage in sha512-avx2-asm.S > > Using RBP as a temporary register breaks frame pointer convention and > breaks stack traces when unwinding from an interrupt in the crypto code. > > Mix things up a little bit to get rid of the RBP usage, without > destroying performance. Use RDI instead of RBP for the TBL pointer. > That will clobber CTX, so save CTX on the stack and use RDI as CTX > before it gets clobbered, and R12 as CTX after it gets clobbered. > > Also remove the unused y4 variable. > I tested the v2 patches for both sha256-avx2 and sha512-avx2 on Skylake. They both pass the crypto self-tests, and there was no noticable performance difference compared to the unpatched versions. Thanks! Eric
