From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
linux-leds@vger.kernel.org, linux-pm@vger.kernel.org,
Mark Rutland <mark.rutland@arm.com>,
Rob Herring <robh@kernel.org>,
Florian Fainelli <f.fainelli@gmail.com>,
Arnd Bergmann <arnd@arndb.de>, Pawel Moll <pawel.moll@arm.com>,
Marc Zyngier <marc.zyngier@arm.com>,
Will Deacon <will.deacon@arm.com>
Subject: Re: [PATCH 7/8] ARM: l2x0: support associativity from DT
Date: Tue, 2 Sep 2014 14:17:29 +0100 [thread overview]
Message-ID: <20140902131729.GQ30401@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1409659354-23553-8-git-send-email-linus.walleij@linaro.org>
On Tue, Sep 02, 2014 at 02:02:33PM +0200, Linus Walleij wrote:
> The ARM RealView platforms comes with boot loaders that fail
> to set up cache size, ways and associativity correctly. This
> complements Florian's patch to set up cache size and sets from
> the device tree with the possibility to set up associativity
> on the L2C-220 cache variant.
Do we need this?
If we have the cache size, the number of sets, and the cache block size
(cache line size) which are all ePAPR specified properties for a cache,
then:
number of cache blocks = cache size / cache block size
ways of associativity = number of cache blocks / number of sets
way size = cache block size * number of sets
It's a tad annoying to have to convert between the two representations,
but ePAPR decided on size, sets and block size rather than size and
ways.
See arch/powerpc/kernel/cacheinfo.c line 260 for the powerpc
associativity calculations from these values.
--
FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up
according to speedtest.net.
next prev parent reply other threads:[~2014-09-02 13:17 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-02 12:02 [PATCH 0/8] ARM RealView DeviceTree support v5 Linus Walleij
2014-09-02 12:02 ` [PATCH 1/8 v2] leds: add a driver for syscon-based LEDs Linus Walleij
2014-09-02 12:02 ` [PATCH 2/8 v2] leds: add device tree bindings for register bit LEDs Linus Walleij
2014-09-02 12:24 ` Arnd Bergmann
2014-09-08 11:25 ` Linus Walleij
2014-09-02 14:22 ` Geert Uytterhoeven
2014-09-08 11:14 ` Linus Walleij
2014-09-02 12:02 ` [PATCH 3/8 v2] power: reset: driver for the Versatile syscon reboot Linus Walleij
2014-09-02 12:32 ` Arnd Bergmann
2014-09-02 12:02 ` [PATCH 4/8] soc: add driver for the ARM RealView Linus Walleij
2014-09-02 12:02 ` [PATCH 5/8] ARM: l2x0: move DT parsing for cache props Linus Walleij
2014-09-02 12:43 ` Russell King - ARM Linux
2014-09-05 11:10 ` Linus Walleij
2014-09-02 12:02 ` [PATCH 6/8] ARM: l2c: parse 'cache-size' and 'cache-sets' properties Linus Walleij
2014-09-02 12:02 ` [PATCH 7/8] ARM: l2x0: support associativity from DT Linus Walleij
2014-09-02 13:17 ` Russell King - ARM Linux [this message]
2014-09-02 12:02 ` [PATCH 8/8 v5] ARM: realview: basic device tree implementation Linus Walleij
2014-09-02 12:37 ` Arnd Bergmann
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