From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 4/6] arm: add early_ioremap support
Date: Thu, 16 Jan 2014 00:35:42 +0000 [thread overview]
Message-ID: <20140116003542.GS15937@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <52D72883.3020500@codeaurora.org>
On Wed, Jan 15, 2014 at 04:32:03PM -0800, Laura Abbott wrote:
> Neither x86 nor arm64 get rid of existing mapping in paging_init. Is
> there a reason this needs to be here for arm? Are there concerns about
> alias mappings?
The early mappings we setup in the assembly code are imperfect - they're
an approximation. We map just about enough memory to get the kernel
going, and we setup a mapping for the debug stuff using a section
mapping, which may not be appropriate.
The permissions too are a just chosen to get things going, and the
subsequent replacement of the page table entries is to fix all that up.
We really don't want any old entries left behind.
--
FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation
in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad.
Estimate before purchase was "up to 13.2Mbit".
next prev parent reply other threads:[~2014-01-16 0:35 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-10 3:50 [PATCH v3 0/6] generic early_ioremap support Mark Salter
2014-01-10 3:50 ` [PATCH v3 2/6] mm: create generic early_ioremap() support Mark Salter
2014-01-10 3:50 ` [PATCH v3 4/6] arm: add early_ioremap support Mark Salter
2014-01-10 11:34 ` Russell King - ARM Linux
2014-01-10 13:50 ` Mark Salter
2014-01-10 16:11 ` Rob Herring
2014-01-10 16:58 ` Catalin Marinas
2014-01-10 20:04 ` Rob Herring
2014-01-10 20:09 ` Rob Herring
2014-01-10 20:51 ` Mark Salter
2014-01-10 20:40 ` Stephen Boyd
2014-01-10 20:52 ` Mark Salter
2014-01-16 0:32 ` Laura Abbott
2014-01-16 0:35 ` Russell King - ARM Linux [this message]
2014-01-16 2:13 ` Mark Salter
2014-01-10 3:50 ` [PATCH v3 5/6] arm64: initialize pgprot info earlier in boot Mark Salter
2014-01-10 3:50 ` [PATCH v3 6/6] arm64: add early_ioremap support Mark Salter
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