From: stefan@agner.ch (Stefan Agner)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 08/12] ARM: allow MULTIPLATFORM with !MMU
Date: Tue, 30 Dec 2014 23:02:31 +0100 [thread overview]
Message-ID: <8ec6bcf0fe2ec13898cf6c259d9da559@agner.ch> (raw)
In-Reply-To: <CAL_JsqK94Pk2xPF1MMX0GU0CQEiwiDD2qv9v3k4WLg2znDVjgA@mail.gmail.com>
On 2014-12-30 22:42, Rob Herring wrote:
> On Mon, Dec 29, 2014 at 5:32 PM, Stefan Agner <stefan@agner.ch> wrote:
>> In order to support SoC with heterogenous CPU architectures (such
>> as Freescale Vybrid/i.MXSX) it is preferable to use the same
>> architecture (ARCH_MXC in this case) for the MMU enabled and !MMU
>> CPU. Hence allow to select MULTIPLATFORM even without MMU.
>
> This has been submitted before[1], but you obviously have a better
> reason now. I also need this for my Versatile series to fix
> allnoconfig. However, there are some issues with your implementation.
>
>> Signed-off-by: Stefan Agner <stefan@agner.ch>
>> ---
>> arch/arm/Kconfig | 21 ++++++++++-----------
>> 1 file changed, 10 insertions(+), 11 deletions(-)
>>
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>> index 97d07ed..95007b9 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -228,7 +228,7 @@ config VECTORS_BASE
>> in size.
>>
>> config ARM_PATCH_PHYS_VIRT
>> - bool "Patch physical to virtual translations at runtime" if EMBEDDED
>> + bool "Patch physical to virtual translations at runtime" if EMBEDDED || (ARCH_MULTIPLATFORM && MMU)
>> default y
>> depends on !XIP_KERNEL && MMU
>> depends on !ARCH_REALVIEW || !SPARSEMEM
>> @@ -303,15 +303,12 @@ config MMU
>> #
>> choice
>> prompt "ARM system type"
>> - default ARCH_VERSATILE if !MMU
>> - default ARCH_MULTIPLATFORM if MMU
>> + default ARCH_MULTIPLATFORM
>>
>> config ARCH_MULTIPLATFORM
>> bool "Allow multiple platforms to be selected"
>> - depends on MMU
>> select ARCH_WANT_OPTIONAL_GPIOLIB
>> select ARM_HAS_SG_CHAIN
>> - select ARM_PATCH_PHYS_VIRT
>> select AUTO_ZRELADDR
>> select CLKSRC_OF
>> select COMMON_CLK
>> @@ -783,13 +780,13 @@ comment "CPU Core family selection"
>>
>> config ARCH_MULTI_V4
>> bool "ARMv4 based platforms (FA526)"
>> - depends on !ARCH_MULTI_V6_V7
>> + depends on !ARCH_MULTI_V6_V7 && MMU
>
> This is not right. !MMU does not mean the ARM arch does not have an
> MMU, but rather the MMU is already setup with identity mapping (or
> some other static mapping).
Yes, I'm aware of that. However, there are several configuration
depending on "!MMU". Allowing !MMU on ARCH_MULTI_V4...V7 would open up
new combination of configurations... This patch avoids this as much as
possible, by making !MMU only available for ARCH_MULTI_V7M.
I'm not sure what tests/verification would be expected before allowing
those new configurations... Personally, I also don't see much value in
allowing these configurations.
--
Stefan
>
> Rob
>
> [1] http://patchwork.ozlabs.org/patch/278996/
next prev parent reply other threads:[~2014-12-30 22:02 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-29 23:32 [PATCH v2 00/12] ARM: vf610m4: Add Vybrid Cortex-M4 support Stefan Agner
2014-12-29 23:32 ` [PATCH v2 01/12] genirq: generic chip: support hierarchy domain Stefan Agner
2014-12-29 23:32 ` [PATCH v2 02/12] irqchip: nvic: support hierarchy irq domain Stefan Agner
2014-12-29 23:32 ` [PATCH v2 03/12] irqchip: vf610-mscm: support NVIC parent Stefan Agner
2014-12-29 23:32 ` [PATCH v2 04/12] irqchip: nvic: increase number of external interrupts to 112 Stefan Agner
2014-12-29 23:32 ` [PATCH v2 05/12] clocksource: add dependencies for Vybrid pit clocksource Stefan Agner
2014-12-29 23:32 ` [PATCH v2 06/12] ARM: unify MMU/!MMU addruart calls Stefan Agner
2014-12-29 23:32 ` [PATCH v2 07/12] ARM: imx: depend MXC debug board on 3DS machines Stefan Agner
2014-12-30 10:42 ` Sergei Shtylyov
2014-12-29 23:32 ` [PATCH v2 08/12] ARM: allow MULTIPLATFORM with !MMU Stefan Agner
2014-12-30 21:42 ` Rob Herring
2014-12-30 22:02 ` Stefan Agner [this message]
2014-12-30 22:27 ` Arnd Bergmann
2014-12-29 23:32 ` [PATCH v2 09/12] ARM: efm32: move into multiplatform Stefan Agner
2015-01-02 9:50 ` Uwe Kleine-König
2014-12-29 23:32 ` [PATCH v2 10/12] ARM: vf610: enable Cortex-M4 on Vybrid SoC Stefan Agner
2014-12-29 23:32 ` [PATCH v2 11/12] ARM: dts: add support for Vybrid running on Cortex-M4 Stefan Agner
2014-12-29 23:32 ` [PATCH v2 12/12] ARM: vf610m4: add defconfig for Linux on Vybrids Cortex-M4 Stefan Agner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=8ec6bcf0fe2ec13898cf6c259d9da559@agner.ch \
--to=stefan@agner.ch \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).