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From: "Shilimkar, Santosh" <santosh.shilimkar@ti.com>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
	Aneesh V <aneesh@ti.com>,
	linux-arm <linux-arm-kernel@lists.infradead.org>,
	Joe Woodward <jw@terrafix.co.uk>
Subject: Re: OMAP3 L2/outer cache enabled in kernel (after being disabled by uBoot)?
Date: Tue, 17 Jan 2012 21:11:37 +0100	[thread overview]
Message-ID: <CAMQu2gyjGYooWih=cK72VYEe8X_bKyOi3_eHec7cWi37CHBoJQ@mail.gmail.com> (raw)
In-Reply-To: <20120117194724.GI16726@n2100.arm.linux.org.uk>

On Tue, Jan 17, 2012 at 8:47 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Tue, Jan 17, 2012 at 04:27:21PM +0000, Catalin Marinas wrote:
>> Anyway, the first step is this API provided by the secure firmware.
>> Since such API may need to be called before the MMU is initialised,
>> Linux would need to have knowledge of the platform type early on. Having
>> some platform hook (asm macro) to call early on wouldn't work with the
>> single zImage configuration. Stack space is not an issue as we already
>> have one for ARMv7 for D-cache flushing (XIP kernels would work but they
>> aren't that many).
>
> It _is_ a problem.  How much stack space would these undefined platform
> specific functions require?  16 words?  32 words?  A page?  Where does
> this memory come from?  The .data section, or are we going to stuff it
> into what is supposed to be the read-only text section?

Stack requirement is limited to saving and restoring the processor
registers. There is no additional need. If this is an issue, we can also use
SRAM as a stack for this operation.

Regards
Santosh
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  reply	other threads:[~2012-01-17 20:12 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-16 10:03 OMAP3 L2/outer cache enabled in kernel (after being disabled by uBoot)? Joe Woodward
2012-01-16 10:18 ` Shilimkar, Santosh
2012-01-16 10:59   ` Russell King - ARM Linux
2012-01-16 12:43     ` Shilimkar, Santosh
2012-01-16 13:13       ` Russell King - ARM Linux
2012-01-16 13:22         ` Shilimkar, Santosh
2012-01-17  8:54           ` Joe Woodward
2012-01-17 12:11             ` Catalin Marinas
2012-01-17 12:27               ` Aneesh V
     [not found]                 ` <CAMQu2gyft96O61Toja-h-MPpzFTQ8dpJWauw3o6qcPQBXEC_6A@mail.gmail.com>
2012-01-17 13:39                   ` Catalin Marinas
2012-01-17 13:58                     ` Shilimkar, Santosh
2012-01-17 16:27                       ` Catalin Marinas
2012-01-17 17:27                         ` Shilimkar, Santosh
2012-01-17 19:39                           ` Nicolas Pitre
2012-01-17 20:27                             ` Shilimkar, Santosh
2012-01-17 20:45                               ` Nicolas Pitre
2012-01-17 20:57                                 ` Nicolas Pitre
2012-01-17 20:58                                 ` Shilimkar, Santosh
2012-01-17 21:02                                   ` Nicolas Pitre
2012-01-18  8:43                                     ` Shilimkar, Santosh
2012-01-17 21:15                               ` Russell King - ARM Linux
2012-01-17 19:47                         ` Russell King - ARM Linux
2012-01-17 20:11                           ` Shilimkar, Santosh [this message]
2012-01-17 20:48                             ` Russell King - ARM Linux
2012-01-17 19:43                       ` Russell King - ARM Linux
2012-01-20  8:57                       ` Joe Woodward
2012-01-27 11:45                         ` Joe Woodward
2012-01-27 17:30                         ` Catalin Marinas
2012-01-31  5:21                           ` Aneesh V
2012-01-31  7:31                             ` Catalin Marinas
2012-01-31  7:38                               ` Shilimkar, Santosh
2012-01-31  8:54                                 ` Catalin Marinas
2012-01-31  9:05                                   ` Shilimkar, Santosh
2012-01-31  9:53                                     ` Catalin Marinas
2012-01-31 10:10                                       ` Russell King - ARM Linux
2012-01-31 12:10                                         ` Catalin Marinas
2012-01-31 18:09                                       ` Nicolas Pitre
2012-02-02 14:32                                         ` Catalin Marinas
2012-02-02 14:49                                           ` Russell King - ARM Linux
2012-02-02 15:10                                             ` Catalin Marinas
2012-01-31  9:56                                     ` Russell King - ARM Linux
2012-01-31 10:51                                       ` Shilimkar, Santosh
2012-01-31 18:27                                         ` Nicolas Pitre
2012-02-01  7:12                                           ` Shilimkar, Santosh
2012-01-17 14:18                     ` Grazvydas Ignotas
2012-01-17 13:41                 ` Catalin Marinas
2012-01-17 13:54                   ` Aneesh V
2012-01-17 14:23                   ` Måns Rullgård
2012-01-17 12:01           ` Aneesh V

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