Re: [PATCH v2 2/2] arm64: tlb: Use the TLBI RANGE feature in arm64

From: Catalin Marinas <catalin.marinas-5wv7dgnIgG8@public.gmane.org>
To: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Cc: Zhenyu Ye <yezhenyu2-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
	will-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
	suzuki.poulose-5wv7dgnIgG8@public.gmane.org,
	maz-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
	steven.price-5wv7dgnIgG8@public.gmane.org,
	guohanjun-hv44wF8Li93QT0dZR+AlfA@public.gmane.org,
	olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
	arm-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
	xiexiangyou-hv44wF8Li93QT0dZR+AlfA@public.gmane.org,
	prime.zeng-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org,
	zhangshaokun-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org,
	kuhn.chenqun-hv44wF8Li93QT0dZR+AlfA@public.gmane.org,
	linux-tegra <linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH v2 2/2] arm64: tlb: Use the TLBI RANGE feature in arm64
Date: Mon, 13 Jul 2020 18:21:59 +0100	[thread overview]
Message-ID: <20200713172158.GE15829@gaia> (raw)
In-Reply-To: <7237888d-2168-cd8b-c83d-c8e54871793d-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

On Mon, Jul 13, 2020 at 03:44:16PM +0100, Jon Hunter wrote:
> On 13/07/2020 15:39, Zhenyu Ye wrote:
> > On 2020/7/13 22:27, Jon Hunter wrote:
> >> After this change I am seeing the following build errors ...
> >>
> >> /tmp/cckzq3FT.s: Assembler messages:
> >> /tmp/cckzq3FT.s:854: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7'
> >> /tmp/cckzq3FT.s:870: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7'
> >> /tmp/cckzq3FT.s:1095: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7'
> >> /tmp/cckzq3FT.s:1111: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7'
> >> /tmp/cckzq3FT.s:1964: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7'
> >> /tmp/cckzq3FT.s:1980: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7'
> >> /tmp/cckzq3FT.s:2286: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7'
> >> /tmp/cckzq3FT.s:2302: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7'
> >> /tmp/cckzq3FT.s:4833: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6'
> >> /tmp/cckzq3FT.s:4849: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6'
> >> /tmp/cckzq3FT.s:5090: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6'
> >> /tmp/cckzq3FT.s:5106: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6'
> >> /tmp/cckzq3FT.s:874: Error: attempt to move .org backwards
> >> /tmp/cckzq3FT.s:1115: Error: attempt to move .org backwards
> >> /tmp/cckzq3FT.s:1984: Error: attempt to move .org backwards
> >> /tmp/cckzq3FT.s:2306: Error: attempt to move .org backwards
> >> /tmp/cckzq3FT.s:4853: Error: attempt to move .org backwards
> >> /tmp/cckzq3FT.s:5110: Error: attempt to move .org backwards
> >> scripts/Makefile.build:280: recipe for target 'arch/arm64/mm/hugetlbpage.o' failed
> >> make[3]: *** [arch/arm64/mm/hugetlbpage.o] Error 1
> >> scripts/Makefile.build:497: recipe for target 'arch/arm64/mm' failed
> >> make[2]: *** [arch/arm64/mm] Error 2
> > 
> > The code must be built with binutils >= 2.30.
> > Maybe I should add  a check on whether binutils supports ARMv8.4-a instructions...
> 
> Yes I believe so.

The binutils guys in Arm confirmed that assembling "tlbi rvae1is"
without -march=armv8.4-a is a bug. When it gets fixed, checking for the
binutils version is not sufficient without passing -march. I think we
are better off with a manual encoding of the instruction.

-- 
Catalin