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From: gregory.clement@free-electrons•com (Gregory CLEMENT)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 00/44] outer cache changes
Date: Wed, 26 Mar 2014 21:05:43 +0100	[thread overview]
Message-ID: <53333317.7020900@free-electrons.com> (raw)
In-Reply-To: <20140317001302.GY21483@n2100.arm.linux.org.uk>

Hi Russell,

On 17/03/2014 01:13, Russell King - ARM Linux wrote:
> This patch series is where I'm currently at with the total mess which
> is L2 cache support.  That's putting it mildly.  This isn't intended
> for anyone to pick up - this is still mostly in development.
> 
> I need help with the Aurora/Tauros3/Broadcom stuff, as that remains
> addicted to the old buggy code that we used to have (eg, if you build
> a v6+v7 kernel, all PL310 errata get disabled.  If CONFIG_CACHE_PL310
> is enabled and you actually have a L2C-220, the necessary waits will
> be omitted.  If you enable erratum 588369 and set the .set_debug
> method to NULL or have a PL310 later than R3P0, you're opening a
> race condition. etc.)
> 
> One of the potentially explosive issues is the utter crap and fscked
> state of DT implementation here, much of which /can't/ now be fixed
> without breaking existing DT based booting with existing files,
> because we have a mixture of DT properties combined with platform
> specific code setting various L2C configuration parameters (sometimes
> writing directly to the registers.)
> 
> For example, I've made a start at trying to prevent any further additions
> of platform code writing to the L2C-310's power control register by
> adding a couple of properties - but we can't delete the direct register
> write in iMX6 code without breaking existing DT descriptions.
> 
> The same goes for the mess which is the auxillary control register,
> or now the prefetch control register.  Or the erratum 752271 which
> iMX6 implements in their own SoC specific code.
> 
> Here's the *big* explosive question: how have we ended up in this mess?
> A bigger question: why was none of this caught at review time?  An even
> bigger question (which I believe is at the root of much of the pain that
> people feel with DT): why aren't device properties being thought out
> better - by that I mean, why isn't the question "are the properties you
> are proposing for device X sufficient to describe all it's configurable
> parameters, and if not, what are you omitting?" being asked when new
> device bindings are being proposed.
> 
> You can see the extent of the L2C crap from the diffstat below - every
> arch/arm/mach-* file touched here is a symptom of failing to adequately
> describe the properties that platforms need to specify.  It's a failing
> of DT process.  It's a failing of review of SoC code.
> 

I had a quick look on this series and it is a really good improvement of
the code. I didn't notice anything suspicious regarding the Aurora L2
cache controller.

Then I have applied this series on 3.14-rc8 using our mvebu_defconfig. And
made some performance tests using cachebench. So I tested it on:

- an Armada XP based board which use the Aurora cache controller with the
aurora-system-cache flavor.

- an Armada 370 based board which use the Aurora cache controller with the
aurora-outer-cache.

I didn't notice any regression in both case.

So at least you can add my

Tested-by: Gregory CLEMENT <gregory.clement@free-electrons•com>


Thanks for your work,

Gregory


> Anyway, here's the diffstat so far.  Not Cc'ing anyone this time around
> (the Cc list is huge), so it's all on LAKML.
> 
>  Documentation/devicetree/bindings/arm/l2cc.txt |    2 +
>  arch/arm/Kconfig                               |   51 -
>  arch/arm/boot/dts/imx6qdl.dtsi                 |    2 +
>  arch/arm/boot/dts/imx6sl.dtsi                  |    2 +
>  arch/arm/include/asm/hardware/cache-l2x0.h     |   63 +-
>  arch/arm/include/asm/outercache.h              |   67 +-
>  arch/arm/mach-cns3xxx/core.c                   |    8 +-
>  arch/arm/mach-highbank/highbank.c              |   12 +-
>  arch/arm/mach-imx/system.c                     |    8 +-
>  arch/arm/mach-omap2/omap-mpuss-lowpower.c      |    2 +-
>  arch/arm/mach-omap2/omap4-common.c             |   58 +-
>  arch/arm/mach-prima2/l2x0.c                    |    5 +-
>  arch/arm/mach-prima2/pm.c                      |    1 -
>  arch/arm/mach-realview/realview_pbx.c          |    4 +-
>  arch/arm/mach-spear/platsmp.c                  |   19 +-
>  arch/arm/mach-spear/spear13xx.c                |    6 +-
>  arch/arm/mach-sti/board-dt.c                   |    8 +-
>  arch/arm/mach-tegra/sleep.h                    |    8 +-
>  arch/arm/mach-ux500/cache-l2x0.c               |   23 +-
>  arch/arm/mach-vexpress/ct-ca9x4.c              |    4 +-
>  arch/arm/mm/Kconfig                            |   51 +
>  arch/arm/mm/Makefile                           |    1 +
>  arch/arm/mm/cache-feroceon-l2.c                |    1 -
>  arch/arm/mm/cache-l2x0.c                       | 1354 +++++++++++++++++-------
>  arch/arm/mm/l2c-common.c                       |   20 +
>  arch/arm/plat-samsung/s5p-sleep.S              |    8 +-
>  26 files changed, 1221 insertions(+), 567 deletions(-)
> 


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

  parent reply	other threads:[~2014-03-26 20:05 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-17  0:13 [PATCH 00/44] outer cache changes Russell King - ARM Linux
2014-03-17  0:13 ` [PATCH 01/44] ARM: l2c: remove outer_inv_all() method Russell King
2014-03-17  0:13 ` [PATCH 02/44] ARM: l2c: remove unnecessary call to outer_flush_all() Russell King
2014-03-17  0:13 ` [PATCH 03/44] ARM: l2c: avoid calling outer_flush_all() unnecessarily (Spear) Russell King
2014-03-17  0:13 ` [PATCH 04/44] ARM: l2c: add helper for L2 cache controller DT IDs Russell King
2014-03-26 20:30   ` Rob Herring
2014-03-17  0:13 ` [PATCH 05/44] ARM: l2c: tidy up l2x0_of_data declarations Russell King
2014-03-17  0:14 ` [PATCH 06/44] ARM: l2c: rename OF specific things, making l2x0_of_data available to all Russell King
2014-03-17  0:14 ` [PATCH 07/44] ARM: l2c: provide generic function for calling set_debug method Russell King
2014-03-17  0:14 ` [PATCH 08/44] ARM: l2c: split out cache unlock code Russell King
2014-03-17  0:14 ` [PATCH 09/44] ARM: l2c: provide generic helper for way-based operations Russell King
2014-03-17  0:14 ` [PATCH 10/44] ARM: l2c: rename cache_wait_way() Russell King
2014-03-17  0:14 ` [PATCH 11/44] ARM: l2c: use add L2C revision constants Russell King
2014-03-17  0:14 ` [PATCH 12/44] ARM: l2c: clean up OF initialisation a bit Russell King
2014-03-17  0:14 ` [PATCH 13/44] ARM: l2c: pass iomem address into data->save function Russell King
2014-03-17  0:14 ` [PATCH 14/44] ARM: l2c: move l2c save function to __l2c_init() Russell King
2014-03-17  0:14 ` [PATCH 15/44] ARM: l2c: provide enable method Russell King
2014-03-17  0:14 ` [PATCH 16/44] ARM: l2c: move aurora broadcast setup to enable function Russell King
2014-03-17  0:14 ` [PATCH 17/44] ARM: l2c: group implementation specific code together Russell King
2014-03-17  0:15 ` [PATCH 18/44] ARM: l2c: implement fixups for L2 cache controller quirks/errata Russell King
2014-03-17  0:15 ` [PATCH 19/44] ARM: l2c: clean up L2 cache initialisation messages Russell King
2014-03-17  0:15 ` [PATCH 20/44] ARM: l2c: split L2C-310 enable function from l2x0 code Russell King
2014-03-17  0:15 ` [PATCH 21/44] ARM: l2c: move and add ARM L2C-2x0/L2C-310 save/resume code to non-OF Russell King
2014-03-17  0:15 ` [PATCH 22/44] ARM: l2c: clean up save/resume functions Russell King
2014-03-17  0:15 ` [PATCH 23/44] ARM: l2c: simplify l2x0 unlocking code Russell King
2014-03-17  0:15 ` [PATCH 24/44] ARM: l2c: move pl310_set_debug() into l2c-310 code Russell King
2014-03-17  0:15 ` [PATCH 25/44] ARM: l2c: add L2C-210 specific handlers Russell King
2014-03-17  0:15 ` [PATCH 26/44] ARM: l2c: implement L2C-310 erratum 727915 as a method override Russell King
2014-03-17  0:15 ` [PATCH 27/44] ARM: l2c: Implement L2C-310 erratum 588369 " Russell King
2014-03-17  0:15 ` [PATCH 28/44] ARM: l2c: use L2C-210 handlers for L2C-310 errata-less implementations Russell King
2014-03-17  0:15 ` [PATCH 29/44] ARM: l2c: add L2C-220 specific handlers Russell King
2014-03-17  0:16 ` [PATCH 30/44] ARM: l2c: remove obsolete l2x0 ops for non-OF init Russell King
2014-03-17  0:16 ` [PATCH 31/44] ARM: l2c: move type string into l2c_init_data structure Russell King
2014-03-17  0:16 ` [PATCH 32/44] ARM: l2c: add decode for L2C-220 cache ways Russell King
2014-03-17  0:16 ` [PATCH 33/44] ARM: l2c: move way size calculation data into l2c_init_data Russell King
2014-03-17  0:16 ` [PATCH 34/44] ARM: outer cache: add documentation of outer cache functions Russell King
2014-03-17  0:16 ` [PATCH 35/44] ARM: outer cache: add WARN_ON() to outer_disable() Russell King
2014-03-17  0:16 ` [PATCH 36/44] ARM: l2c: move errata configuration options to arch/arm/mm/Kconfig Russell King
2014-03-17  0:16 ` [PATCH 37/44] ARM: l2c: provide generic hook to intercept writes to secure registers Russell King
2014-03-17  0:16 ` [PATCH 38/44] ARM: l2c: OMAP: implement new write_sec method Russell King
2014-03-17  0:16 ` [PATCH 39/44] ARM: l2c: highbank: " Russell King
2014-03-26 20:35   ` Rob Herring
2014-03-17  0:16 ` [PATCH 40/44] ARM: l2c: ux500: implement dummy " Russell King
2014-03-17  0:17 ` [PATCH 41/44] ARM: l2c: remove old .set_debug method Russell King
2014-03-17  0:17 ` [PATCH 42/44] ARM: l2c: implement L2C-310 erratum 752271 in core L2C code Russell King
2014-03-17  0:17 ` [PATCH 43/44] ARM: l2c: rename all L2C-310 constants with an L310_ prefix Russell King
2014-03-17  0:17 ` [PATCH 44/44] ARM: l2c: add L2C-310 power control DT properties Russell King
2014-03-26 21:08   ` Rob Herring
2014-03-28 13:29     ` Russell King - ARM Linux
2014-03-26 20:05 ` Gregory CLEMENT [this message]
2014-03-28 18:50 ` [PATCH 00/44] outer cache changes Nishanth Menon

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