From mboxrd@z Thu Jan 1 00:00:00 1970 From: lorenzo.pieralisi@arm.com (Lorenzo Pieralisi) Date: Mon, 20 Apr 2015 11:21:55 +0100 Subject: [PATCH] arm64: kill flush_cache_all() In-Reply-To: <1429521875-16893-1-git-send-email-mark.rutland@arm.com> References: <1429521875-16893-1-git-send-email-mark.rutland@arm.com> Message-ID: <20150420102155.GA12507@red-moon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Apr 20, 2015 at 10:24:35AM +0100, Mark Rutland wrote: > The documented semantics of flush_cache_all are not possible to provide > for arm64 (short of flushing the entire physical address space by VA), > and there are currently no users; KVM uses VA maintenance exclusively, > cpu_reset is never called, and the only two users outside of arch code > cannot be built for arm64. > > While cpu_soft_reset and related functions (which call flush_cache_all) > were thought to be useful for kexec, their current implementations only > serve to mask bugs. For correctness kexec will need to perform > maintenance by VA anyway to account for system caches, line migration, > and other subtleties of the cache architecture. As the extent of this > cache maintenance will be kexec-specific, it should probably live in the > kexec code. > > This patch removes flush_cache_all, and related unused components, > preventing further abuse. > > Signed-off-by: Mark Rutland > Cc: AKASHI Takahiro > Cc: Ard Biesheuvel > Cc: Catalin Marinas > Cc: Geoff Levand > Cc: Lorenzo Pieralisi > Cc: Marc Zyngier > Cc: Will Deacon > --- > arch/arm64/include/asm/cacheflush.h | 5 --- > arch/arm64/include/asm/proc-fns.h | 4 -- > arch/arm64/include/asm/system_misc.h | 1 - > arch/arm64/kernel/process.c | 12 +----- > arch/arm64/mm/cache.S | 73 ------------------------------------ > arch/arm64/mm/flush.c | 1 - > arch/arm64/mm/proc.S | 46 ----------------------- > 7 files changed, 1 insertion(+), 141 deletions(-) Acked-by: Lorenzo Pieralisi Lorenzo