On Wed, Aug 5, 2020 at 11:19 AM Sami Tolvanen <samitolva...@google.com> wrote:
>
> Commit 7c78f67e9bd9 ("arm64: enable tlbi range instructions") breaks
> LLVM's integrated assembler, because -Wa,-march is only passed to
> external assemblers and therefore, the new instructions are not enabled
> when IAS is used.
>
> As binutils doesn't support .arch_extension tlb-rmi, this change adds
> .arch armv8.4-a to __TLBI_0 and __TLBI_1 to fix the issue with both LLVM
> IAS and binutils.
>
> Fixes: 7c78f67e9bd9 ("arm64: enable tlbi range instructions")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1106
> Signed-off-by: Sami Tolvanen <samitolva...@google.com>I've filed https://sourceware.org/bugzilla/show_bug.cgi?id=26339 to discuss more with ARM binutils devs about some of the compat issues around these assembler directives. > --- > arch/arm64/include/asm/tlbflush.h | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/tlbflush.h > b/arch/arm64/include/asm/tlbflush.h > index d493174415db..66c2aab5e9cb 100644 > --- a/arch/arm64/include/asm/tlbflush.h > +++ b/arch/arm64/include/asm/tlbflush.h > @@ -16,6 +16,16 @@ > #include <asm/cputype.h> > #include <asm/mmu.h> > > +/* > + * Enable ARMv8.4-TLBI instructions with ARM64_TLB_RANGE. Note that binutils > + * doesn't support .arch_extension tlb-rmi, so use .arch armv8.4-a instead. > + */ > +#ifdef CONFIG_ARM64_TLB_RANGE > +#define __TLBI_PREAMBLE ".arch armv8.4-a\n" > +#else > +#define __TLBI_PREAMBLE > +#endif > + > /* > * Raw TLBI operations. > * > @@ -28,14 +38,16 @@ > * not. The macros handles invoking the asm with or without the > * register argument as appropriate. > */ > -#define __TLBI_0(op, arg) asm ("tlbi " #op "\n" > \ > +#define __TLBI_0(op, arg) asm (__TLBI_PREAMBLE > \ > + "tlbi " #op "\n" > \ > ALTERNATIVE("nop\n nop", > \ > "dsb ish\n tlbi " #op, > \ > ARM64_WORKAROUND_REPEAT_TLBI, > \ > CONFIG_ARM64_WORKAROUND_REPEAT_TLBI) > \ > : : ) > > -#define __TLBI_1(op, arg) asm ("tlbi " #op ", %0\n" > \ > +#define __TLBI_1(op, arg) asm (__TLBI_PREAMBLE > \ > + "tlbi " #op ", %0\n" > \ > ALTERNATIVE("nop\n nop", > \ > "dsb ish\n tlbi " #op ", %0", > \ > ARM64_WORKAROUND_REPEAT_TLBI, > \ > > base-commit: 4834ce9d8e074bb7ae197632e0708219b9f389b5 > -- > 2.28.0.163.g6104cc2f0b6-goog > -- Thanks, ~Nick Desaulniers
