On Thu, May 12, 2022 at 07:24:25PM +0200, Heiko Carstens wrote: > On Wed, May 11, 2022 at 10:30:05AM -0700, Nathan Chancellor wrote: > > Hi Heiko, > > > > On Wed, May 11, 2022 at 02:05:28PM +0200, Heiko Carstens wrote: > > > llvm's integrated assembler cannot handle immediate values which are > > > calculated with two local labels: > > > > > > <instantiation>:3:13: error: invalid operand for instruction > > > clgfi %r14,.Lsie_done - .Lsie_gmap > > > > > > Workaround this by adding clang specific code which reads the specific > > > value from memory. Since this code is within the hot paths of the kernel > > > and adds an additional memory reference, keep the original code, and add > > > ifdef'ed code. > > > > > > Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx> > > > --- > > > arch/s390/kernel/entry.S | 11 +++++++++++ > > > 1 file changed, 11 insertions(+) > > > > > > diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S > > > index e1664b45090f..ff7a75078e93 100644 > > > --- a/arch/s390/kernel/entry.S > > > +++ b/arch/s390/kernel/entry.S > > > @@ -171,8 +171,19 @@ _LPP_OFFSET = __LC_LPP > > > .macro OUTSIDE reg,start,end,outside_label > > > larl %r14,\start > > > slgrk %r14,\reg,%r14 > > > +#ifdef CONFIG_CC_IS_CLANG > > > > I intend to put this series through my build and boot test matrix later > > today but one fly by comment in the meantime. Should this be > > CONFIG_AS_IS_LLVM if this is an integrated assembler limitation, rather > > than a clang one? > > Yes, that makes a lot of sense. Considering that I will drop the > previous patch within this series, the new version looks like: > > From fe4fb0b014378d84ae517deaea338577b2ea6ae0 Mon Sep 17 00:00:00 2001 > From: Heiko Carstens <hca@xxxxxxxxxxxxx> > Date: Sat, 7 May 2022 15:00:40 +0200 > Subject: [PATCH 3/7] s390/entry: workaround llvm's IAS limitations > > llvm's integrated assembler cannot handle immediate values which are > calculated with two local labels: > > <instantiation>:3:13: error: invalid operand for instruction > clgfi %r14,.Lsie_done - .Lsie_gmap > > Workaround this by adding clang specific code which reads the specific > value from memory. Since this code is within the hot paths of the kernel > and adds an additional memory reference, keep the original code, and add > ifdef'ed code. > > Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx> > --- > arch/s390/kernel/entry.S | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S > index a6b45eaa3450..f2f30bfba1e9 100644 > --- a/arch/s390/kernel/entry.S > +++ b/arch/s390/kernel/entry.S > @@ -172,9 +172,19 @@ _LPP_OFFSET = __LC_LPP > lgr %r14,\reg > larl %r13,\start > slgr %r14,%r13 > - lghi %r13,\end - \start > - clgr %r14,%r13 > +#ifdef CONFIG_AS_IS_LLVM > + clgfrl %r14,.Lrange_size\@ > +#else > + clgfi %r14,\end - \start > +#endif > jhe \outside_label > +#ifdef CONFIG_CC_IS_CLANG I think this one also wants to be CONFIG_AS_IS_LLVM, right? Other than that, seems fine to me, although I have no knowledge of s390 assembly so that statement probably means next to nothing :) Cheers, Nathan > + .section .rodata, "a" > + .align 4 > +.Lrange_size\@: > + .long \end - \start > + .previous > +#endif > .endm > > .macro SIEEXIT > -- > 2.32.0
