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Create large page mappings in pmap_map().

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MFC after:	6 weeks
This commit is contained in:
Alan Cox 2011-12-14 23:57:47 +00:00
parent 1fc7f6471e
commit 894b2848d3
1 changed files with 32 additions and 4 deletions
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36
sys/i386/i386/pmap.c
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@ -1450,12 +1450,40 @@ vm_offset_t
pmap_map(vm_offset_t *virt, vm_paddr_t start, vm_paddr_t end, int prot)
{
vm_offset_t va, sva;
vm_paddr_t superpage_offset;
pd_entry_t newpde;
va = sva = *virt;
va = *virt;
/*
* Does the physical address range's size and alignment permit at
* least one superpage mapping to be created?
*/
superpage_offset = start & PDRMASK;
if ((end - start) - ((NBPDR - superpage_offset) & PDRMASK) >= NBPDR) {
/*
* Increase the starting virtual address so that its alignment
* does not preclude the use of superpage mappings.
*/
if ((va & PDRMASK) < superpage_offset)
va = (va & ~PDRMASK) + superpage_offset;
else if ((va & PDRMASK) > superpage_offset)
va = ((va + PDRMASK) & ~PDRMASK) + superpage_offset;
}
sva = va;
while (start < end) {
pmap_kenter(va, start);
va += PAGE_SIZE;
start += PAGE_SIZE;
if ((start & PDRMASK) == 0 && end - start >= NBPDR &&
pseflag) {
KASSERT((va & PDRMASK) == 0,
("pmap_map: misaligned va %#x", va));
newpde = start | PG_PS | pgeflag | PG_RW | PG_V;
pmap_kenter_pde(va, newpde);
va += NBPDR;
start += NBPDR;
} else {
pmap_kenter(va, start);
va += PAGE_SIZE;
start += PAGE_SIZE;
}
}
pmap_invalidate_range(kernel_pmap, sva, va);
*virt = va;