Area* AddressSpace::CreateArea(const char name[], unsigned int size, AreaWiring wiring,
PageProtection protection, PageCache *cache, off_t offset, unsigned int va,
int flags)
{
if (size % PAGE_SIZE != 0 || size == 0)
return 0;
if (cache != 0 && cache->Commit(offset + size) != offset + size)
return 0;
fAreaLock.LockWrite();
if (va == INVALID_PAGE)
va = FindFreeRange(size, flags);
else if (va % PAGE_SIZE != 0 || !fAreas.IsRangeFree(va, va + size - 1))
va = INVALID_PAGE;
Area *area = 0;
if (va != INVALID_PAGE) {
area = new Area(name, protection, cache, offset, wiring);
fAreas.Add(area, va, va + size - 1);
if (wiring & AREA_WIRED) {
for (unsigned int aroffs = 0; aroffs < size; aroffs += PAGE_SIZE) {
Page *page = area->GetPageCache()->GetPage(area->GetCacheOffset()
+ aroffs, false);
page->Wire();
fPhysicalMap->Map(va + aroffs, page->GetPhysicalAddress(), protection);
}
}
}
fChangeCount++;
fAreaLock.UnlockWrite();
return area;
}
status_t AddressSpace::ResizeArea(Area *area, unsigned int newSize)
{
if (newSize == 0)
return E_INVALID_OPERATION;
fAreaLock.LockWrite();
if (newSize > area->GetSize()) {
// Grow the area.
if (area->GetPageCache()->Commit(newSize) != newSize) {
fAreaLock.UnlockWrite();
return E_NO_MEMORY;
}
if (area->GetBaseAddress() + newSize < area->GetBaseAddress() // wrap
|| !fAreas.IsRangeFree(area->GetBaseAddress() + area->GetSize(),
area->GetBaseAddress() + newSize)) {
fAreaLock.UnlockWrite();
return E_NO_MEMORY;
}
if (area->GetWiring() == AREA_WIRED) {
for (unsigned int aroffs = area->GetSize(); aroffs < newSize;
aroffs += PAGE_SIZE) {
Page *page = area->GetPageCache()->GetPage(area->GetCacheOffset()
+ aroffs, false);
page->Wire();
fPhysicalMap->Map(area->GetBaseAddress() + aroffs, page->GetPhysicalAddress(),
area->GetProtection());
}
}
} else if (newSize < area->GetSize()) {
// Shrink the area.
fPhysicalMap->Unmap(area->GetBaseAddress() + newSize, area->GetSize() - newSize);
area->GetPageCache()->Commit(newSize);
}
fAreas.Resize(area, newSize);
fChangeCount++;
fAreaLock.UnlockWrite();
return E_NO_ERROR;
}
