linux-kernel - Re: [PATCH v2 02/18] ARM: ARMv7M: Enlarge vector table to 256 entries

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 9 Mar 2015 18:12:05 +0100
From:	Maxime Coquelin <mcoquelin.stm32@...il.com>
To:	Stefan Agner <stefan@...er.ch>
Cc:	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>,
	Andreas Färber <afaerber@...e.de>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	Rob Herring <robh+dt@...nel.org>,
	Philipp Zabel <p.zabel@...gutronix.de>,
	Jonathan Corbet <corbet@....net>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Russell King <linux@....linux.org.uk>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Linus Walleij <linus.walleij@...aro.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jiri Slaby <jslaby@...e.cz>, Arnd Bergmann <arnd@...db.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"David S. Miller" <davem@...emloft.net>,
	Mauro Carvalho Chehab <mchehab@....samsung.com>,
	Joe Perches <joe@...ches.com>, Antti Palosaari <crope@....fi>,
	Tejun Heo <tj@...nel.org>, Will Deacon <will.deacon@....com>,
	Nikolay Borisov <Nikolay.Borisov@....com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Kees Cook <keescook@...omium.org>,
	Michal Marek <mmarek@...e.cz>,
	"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
	"linux-serial@...r.kernel.org" <linux-serial@...r.kernel.org>,
	Linux-Arch <linux-arch@...r.kernel.org>,
	"linux-api@...r.kernel.org" <linux-api@...r.kernel.org>
Subject: Re: [PATCH v2 02/18] ARM: ARMv7M: Enlarge vector table to 256 entries

2015-03-09 1:29 GMT+01:00 Stefan Agner <stefan@...er.ch>:
> On 2015-02-20 19:01, Maxime Coquelin wrote:
>> From Cortex-M reference manuals, the nvic supports up to 240 interrupts.
>> So the number of entries in vectors table is up to 256.
>>
>> This patch adds a new config flag to specify the number of external interrupts.
>> Some ifdeferies are added in order to respect the natural alignment without
>> wasting too much space on smaller systems.
>>
>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@...il.com>
>> ---
>>  arch/arm/kernel/entry-v7m.S | 13 +++++++++----
>>  arch/arm/mm/Kconfig         | 15 +++++++++++++++
>>  2 files changed, 24 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/arm/kernel/entry-v7m.S b/arch/arm/kernel/entry-v7m.S
>> index 8944f49..68cde36 100644
>> --- a/arch/arm/kernel/entry-v7m.S
>> +++ b/arch/arm/kernel/entry-v7m.S
>> @@ -117,9 +117,14 @@ ENTRY(__switch_to)
>>  ENDPROC(__switch_to)
>>
>>       .data
>> -     .align  8
>> +#if CONFIG_CPUV7M_NUM_IRQ <= 112
>> +     .align  9
>> +#else
>> +     .align  10
>> +#endif
>> +
>>  /*
>> - * Vector table (64 words => 256 bytes natural alignment)
>> + * Vector table (Natural alignment need to be ensured)
>>   */
>>  ENTRY(vector_table)
>>       .long   0                       @ 0 - Reset stack pointer
>> @@ -138,6 +143,6 @@ ENTRY(vector_table)
>>       .long   __invalid_entry         @ 13 - Reserved
>>       .long   __pendsv_entry          @ 14 - PendSV
>>       .long   __invalid_entry         @ 15 - SysTick
>> -     .rept   64 - 16
>> -     .long   __irq_entry             @ 16..64 - External Interrupts
>> +     .rept   CONFIG_CPUV7M_NUM_IRQ
>> +     .long   __irq_entry             @ External Interrupts
>>       .endr
>> diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
>> index c43c714..27eb835 100644
>> --- a/arch/arm/mm/Kconfig
>> +++ b/arch/arm/mm/Kconfig
>> @@ -604,6 +604,21 @@ config CPU_USE_DOMAINS
>>         This option enables or disables the use of domain switching
>>         via the set_fs() function.
>>
>> +config CPUV7M_NUM_IRQ
>> +     int "Number of external interrupts connected to the NVIC"
>> +     depends on CPU_V7M
>> +     default 90 if ARCH_STM32
>> +     default 38 if ARCH_EFM32
>> +     default 240
>> +     help
>> +       This option indicates the number of interrupts connected to the NVIC.
>> +       The value can be larger than the real number of interrupts supported
>> +       by the system, but must not be lower.
>> +       The default value is 240, corresponding to the maximum number of
>> +       interrupts supported by the NVIC on Cortex-M family.
>> +
>> +       If unsure, keep default value.
>> +
>>  #
>>  # CPU supports 36-bit I/O
>>  #
>
> I sent a patch which extended that vector table some weeks ago:
> https://lkml.org/lkml/2014/12/29/296

I did something similar in my first version.

>
> But your solution is definitely more flexible, and given that we deal
> with small devices here, it's worth saving memory.

Yes, it is worth for these small devices.

>
> Acked-by: Stefan Agner <stefan@...er.ch>
>

Thanks for the review,
Maxime
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/