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author | jah <jah@FreeBSD.org> | 2015-08-04 19:46:13 +0000 |
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committer | jah <jah@FreeBSD.org> | 2015-08-04 19:46:13 +0000 |
commit | b8c4d76738c091ce972e522ec36c8dce6642f6fb (patch) | |
tree | c099d6990763d6142f37775aa84b5193ad0b77fb /sys/vm/pmap.h | |
parent | d6d829914b43c5cfe1482a423d5466cd717a330c (diff) | |
download | FreeBSD-src-b8c4d76738c091ce972e522ec36c8dce6642f6fb.zip FreeBSD-src-b8c4d76738c091ce972e522ec36c8dce6642f6fb.tar.gz |
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.
Reviewed by: kib
Approved by: kib (mentor)
Differential Revision: http://reviews.freebsd.org/D3013
Diffstat (limited to 'sys/vm/pmap.h')
-rw-r--r-- | sys/vm/pmap.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sys/vm/pmap.h b/sys/vm/pmap.h index d73babc..741ba3c 100644 --- a/sys/vm/pmap.h +++ b/sys/vm/pmap.h @@ -152,6 +152,8 @@ void pmap_unwire(pmap_t pmap, vm_offset_t start, vm_offset_t end); void pmap_zero_page(vm_page_t); void pmap_zero_page_area(vm_page_t, int off, int size); void pmap_zero_page_idle(vm_page_t); +vm_offset_t pmap_quick_enter_page(vm_page_t); +void pmap_quick_remove_page(vm_offset_t); #define pmap_resident_count(pm) ((pm)->pm_stats.resident_count) #define pmap_wired_count(pm) ((pm)->pm_stats.wired_count) |