From 63efc821c3e4785928997ea88e1de93e62ce3acb Mon Sep 17 00:00:00 2001 From: kib Date: Thu, 14 Mar 2013 20:18:12 +0000 Subject: 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 --- sys/amd64/amd64/pmap.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'sys/amd64') diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index aa38013..4777c08 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -4272,6 +4272,30 @@ pmap_copy_page(vm_page_t msrc, vm_page_t mdst) pagecopy((void *)src, (void *)dst); } +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 *)PHYS_TO_DMAP(ma[a_offset >> PAGE_SHIFT]-> + phys_addr) + a_pg_offset; + b_pg_offset = b_offset & PAGE_MASK; + cnt = min(cnt, PAGE_SIZE - b_pg_offset); + b_cp = (char *)PHYS_TO_DMAP(mb[b_offset >> PAGE_SHIFT]-> + phys_addr) + 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 -- cgit v1.1