Date: Sat, 15 Aug 2015 15:05:19 +0200 From: =?UTF-8?B?Um9nZXIgUGF1IE1vbm7DqQ==?= <royger@FreeBSD.org> To: "Jason A. Harmening" <jah@FreeBSD.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r286787 - head/sys/x86/x86 Message-ID: <55CF390F.5010407@FreeBSD.org> In-Reply-To: <201508142008.t7EK8Hkt037329@repo.freebsd.org> References: <201508142008.t7EK8Hkt037329@repo.freebsd.org>
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El 14/08/15 a les 22.08, Jason A. Harmening ha escrit: > Author: jah > Date: Fri Aug 14 20:08:16 2015 > New Revision: 286787 > URL: https://svnweb.freebsd.org/changeset/base/286787 > > Log: > Use pmap_quick_enter_page() to handle bouncing of unmapped buffers in the x86 busdma_bounce implementation. Also treat user buffers as unmapped. > This allows two things: > 1. Sync'ing bounced maps in non-sleepable contexts. The physcopy* calls previously used could sleep on sf_buf operations in some cases. > 2. Sync'ing user buffers outside the context of the owning process AFAICT this will break the Xen port. physcopy* uses uiomove_fromphys that on the amd64 port is able to deal with pages outside of the DMAP. OTOH pmap_quick_enter_page is not able to deal with pages outside of the DMAP, and will simply panic. Roger.
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