On 08/04/15 18:22, Bjoern A. Zeeb wrote: > >> On 04 Aug 2015, at 19:46 , Jason A. Harmening <j...@freebsd.org> wrote: >> >> Author: jah >> Date: Tue Aug 4 19:46:13 2015 >> New Revision: 286296 >> URL: https://svnweb.freebsd.org/changeset/base/286296 >> >> Log: >> Add two new pmap functions: >> vm_offset_t pmap_quick_enter_page(vm_page_t m) >> void pmap_quick_remove_page(vm_offset_t kva) >> >> These will create and destroy a temporary, CPU-local KVA mapping of a >> specified page. >> >> Guarantees: >> --Will not sleep and will not fail. >> --Safe to call under a non-sleepable lock or from an ithread >> >> Restrictions: >> --Not guaranteed to be safe to call from an interrupt filter or under a >> spin mutex on all platforms >> --Current implementation does not guarantee more than one page of mapping >> space across all platforms. MI code should not make nested calls to >> pmap_quick_enter_page. >> --MI code should not perform locking while holding onto a mapping created >> by pmap_quick_enter_page >> >> The idea is to use this in busdma, for bounce buffer copies as well as >> virtually-indexed cache maintenance on mips and arm. >> >> NOTE: the non-i386, non-amd64 implementations of these functions still need >> review and testing. > > Most of this description should go into a section 9 man page rather than the > commit message ;-) > > /bz >
Yep, I'm planning to write one. _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
