diff options
author | kib <kib@FreeBSD.org> | 2013-03-14 20:18:12 +0000 |
---|---|---|
committer | kib <kib@FreeBSD.org> | 2013-03-14 20:18:12 +0000 |
commit | 63efc821c3e4785928997ea88e1de93e62ce3acb (patch) | |
tree | 7fc0d10a416efdb974f78de808274b7ebcd9475a /sys/ia64 | |
parent | 4824f825377f483e33c726bad073beda774d9f4b (diff) | |
download | FreeBSD-src-63efc821c3e4785928997ea88e1de93e62ce3acb.zip FreeBSD-src-63efc821c3e4785928997ea88e1de93e62ce3acb.tar.gz |
Add pmap function pmap_copy_pages(), which copies the content of the
pages around, taking array of vm_page_t both for source and
destination. Starting offsets and total transfer size are specified.
The function implements optimal algorithm for copying using the
platform-specific optimizations. For instance, on the architectures
were the direct map is available, no transient mappings are created,
for i386 the per-cpu ephemeral page frame is used. The code was
typically borrowed from the pmap_copy_page() for the same
architecture.
Only i386/amd64, powerpc aim and arm/arm-v6 implementations were
tested at the time of commit. High-level code, not committed yet to
the tree, ensures that the use of the function is only allowed after
explicit enablement.
For sparc64, the existing code has known issues and a stab is added
instead, to allow the kernel linking.
Sponsored by: The FreeBSD Foundation
Tested by: pho (i386, amd64), scottl (amd64), ian (arm and arm-v6)
MFC after: 2 weeks
Diffstat (limited to 'sys/ia64')
-rw-r--r-- | sys/ia64/ia64/pmap.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/sys/ia64/ia64/pmap.c b/sys/ia64/ia64/pmap.c index 1dff1f9..3256600 100644 --- a/sys/ia64/ia64/pmap.c +++ b/sys/ia64/ia64/pmap.c @@ -2014,6 +2014,30 @@ pmap_copy_page(vm_page_t msrc, vm_page_t mdst) bcopy(src, dst, PAGE_SIZE); } +void +pmap_copy_pages(vm_page_t ma[], vm_offset_t a_offset, vm_page_t mb[], + vm_offset_t b_offset, int xfersize) +{ + void *a_cp, *b_cp; + vm_offset_t a_pg_offset, b_pg_offset; + int cnt; + + while (xfersize > 0) { + a_pg_offset = a_offset & PAGE_MASK; + cnt = min(xfersize, PAGE_SIZE - a_pg_offset); + a_cp = (char *)pmap_page_to_va(ma[a_offset >> PAGE_SHIFT]) + + a_pg_offset; + b_pg_offset = b_offset & PAGE_MASK; + cnt = min(cnt, PAGE_SIZE - b_pg_offset); + b_cp = (char *)pmap_page_to_va(mb[b_offset >> PAGE_SHIFT]) + + b_pg_offset; + bcopy(a_cp, b_cp, cnt); + a_offset += cnt; + b_offset += cnt; + xfersize -= cnt; + } +} + /* * Returns true if the pmap's pv is one of the first * 16 pvs linked to from this page. This count may |