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From: Linus Walleij <>
To: Ard Biesheuvel <>
Cc: linux-efi <>,
	Linux ARM <>,
	Russell King <>,
	Marc Zyngier <>, Nicolas Pitre <>,
	Catalin Marinas <>,
	Tony Lindgren <>
Subject: Re: [PATCH v3 0/5] ARM: decompressor: use by-VA cache maintenance for v7 cores
Date: Tue, 25 Feb 2020 16:48:12 +0100
Message-ID: <> (raw)
In-Reply-To: <>

On Mon, Feb 24, 2020 at 1:17 PM Ard Biesheuvel <> wrote:

> 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 on systems
> like SynQuacer, for which 32-bit firmware is available, the current cache
> maintenance only pushes the data out to the L3 system cache, where it
> is not visible to the CPU once it turns the MMU and caches off.
> So instead, switch to the by-VA cache maintenance that the architecture
> requires for v7 and later (and ARM1176, as a side effect).

I took this v3 patch set for a ride on some ARMv7 and ARMv6
(hardware) boards using zImage:s so the compressed path
should be exercised:

- Ux500 (ARMv7 Cortex A9 x 2) works like a charm
- RealView PB11MPCore (ARM1176 x 4 MPCore) works like a charm

Tested-by: Linus Walleij <>

I can do more thorough tests with more boards if needed.

Linus Walleij

  parent reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-24 12:17 Ard Biesheuvel
2020-02-24 12:17 ` [PATCH v3 1/5] efi/arm: Work around missing cache maintenance in decompressor handover Ard Biesheuvel
2020-02-24 12:17 ` [PATCH v3 2/5] efi/arm: Pass start and end addresses to cache_clean_flush() Ard Biesheuvel
2020-02-24 12:17 ` [PATCH v3 3/5] ARM: decompressor: factor out routine to obtain the inflated image size Ard Biesheuvel
2020-02-24 12:17 ` [PATCH v3 4/5] ARM: decompressor: prepare cache_clean_flush for doing by-VA maintenance Ard Biesheuvel
2020-02-24 12:17 ` [PATCH v3 5/5] ARM: decompressor: switch to by-VA cache maintenance for v7 cores Ard Biesheuvel
2020-02-25 15:48 ` Linus Walleij [this message]
2020-02-25 17:18   ` [PATCH v3 0/5] ARM: decompressor: use " Ard Biesheuvel
2020-02-25 17:30     ` Ard Biesheuvel
2020-02-25 21:25     ` Linus Walleij

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