From: Ard Biesheuvel <ardb@kernel.org>
To: linux-efi@vger.kernel.org
Cc: Nicolas Pitre <nico@fluxnic.net>, Marc Zyngier <maz@kernel.org>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH 0/2] ARM: decompressor: use by-VA cache maintenance for v7 cores
Date: Tue, 18 Feb 2020 17:44:28 +0100 [thread overview]
Message-ID: <20200218164430.32671-1-ardb@kernel.org> (raw)
While making changes to the EFI stub startup code, I noticed that we are
still doing set/way maintenance on the caches when booting on v7 cores.
This works today on VMs by virtue of the fact that KVM traps set/way ops
and cleans the whole address space by VA on behalf of the guest, and on
most v7 hardware, the set/way ops are in fact sufficient when only one
core is running, as there usually is no system cache.
But let's make this code a bit more future proof, by switching to by-VA
ops for the v7 code paths (and for ARM1176, as a side effect).
Note that these patches are based on an EFI stub fix that I have omitted
here, and which can be found at
https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/commit/?h=arm32-efi-cache-ops&id=01d742dcf0a3dce6f6db9e4661750129bc3d3216
Cc: Russell King <linux@armlinux.org.uk>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Ard Biesheuvel (2):
ARM: decompressor: prepare cache_clean_flush for doing by-VA
maintenance
ARM: decompressor: switch to by-VA cache maintenance for v7 cores
arch/arm/boot/compressed/head.S | 105 ++++++++++----------
1 file changed, 54 insertions(+), 51 deletions(-)
--
2.17.1
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next reply other threads:[~2020-02-18 16:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 16:44 Ard Biesheuvel [this message]
2020-02-18 16:44 ` [PATCH 1/2] ARM: decompressor: prepare cache_clean_flush for doing by-VA maintenance Ard Biesheuvel
2020-02-18 16:51 ` Russell King - ARM Linux admin
2020-02-18 16:56 ` Ard Biesheuvel
2020-02-18 17:08 ` Russell King - ARM Linux admin
2020-02-18 16:44 ` [PATCH 2/2] ARM: decompressor: switch to by-VA cache maintenance for v7 cores Ard Biesheuvel
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