svn commit: r286787 - head/sys/x86/x86

[Roger Pau Monné]

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.