[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH 2/3] x86/boot: Simplify address calculations in move_memory()
- To: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
- From: "Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>
- Date: Tue, 22 Oct 2024 20:16:41 -0400
- Arc-authentication-results: i=1; mx.zohomail.com; dkim=pass header.i=apertussolutions.com; spf=pass smtp.mailfrom=dpsmith@xxxxxxxxxxxxxxxxxxxx; dmarc=pass header.from=<dpsmith@xxxxxxxxxxxxxxxxxxxx>
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1729642604; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=Ihha2WkaDo8YK9TFfNt/9gjktJNn6lcUbCtF1XUysTY=; b=NjQDmI3Kcv8igoXxBCwSPPWteL2lii3ce6W9Fc1WMSzP/gMPQYtXEb0aZ6/1UjmPijEiL+7YSpZ8LmyacCvHEt9JoDBzr60cH5c58dXZCJL0eNGLPG73a0VQmKSDjFzfHPwS+e6eipZhi0ci4I7sa5Bj805buOyDci6xBF+PN9U=
- Arc-seal: i=1; a=rsa-sha256; t=1729642604; cv=none; d=zohomail.com; s=zohoarc; b=G/ySipiSpB+0hsRgKZXWUgr+T0n2D1mQzUtKE6PJCBib8Htl6SrlcemUOOL4/oOLGGybgnc0sF5CDbqTrNgsdDpKgQrNlaz8rq+4fNgUUim90/0joasc6iq9DucVZQlkwzJifHCnFlhaFKZRQMOWjSE0rlusm08W0HZPcG6LLkg=
- Cc: Jan Beulich <JBeulich@xxxxxxxx>, Roger Pau Monné <roger.pau@xxxxxxxxxx>
- Delivery-date: Wed, 23 Oct 2024 00:16:52 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On 10/22/24 18:39, Andrew Cooper wrote:
Given that soffs is the offset into the 2M superpage,
start = (src - soffs) >> PAGE_SIFT
is a complicated expression for the frame address of the containing superpage.
Except, start is converted straight back to a byte address to use, so the
shifting is unnecessary too.
The only done with the mapped pointer is to have soffs added back on for the
nit: think you dropped a word here, "The only done".
memmove() call. bootstrap_map_addr() passes through the offset, so we can
pass src directly in and simplify the memmove() call too. For the end mapping
address, this simplifies to just src + sz too.
The same reasoning holds for dst and doffs.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
After nit,
Reviewed-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
|
