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#include <Kernel/VM/Region.h>
#include <Kernel/VM/VMObject.h>
#include <Kernel/VM/MemoryManager.h>
#include <Kernel/Process.h>
#include <Kernel/Thread.h>
Region::Region(LinearAddress a, size_t s, String&& n, bool r, bool w, bool cow)
: m_laddr(a)
, m_size(s)
, m_vmo(VMObject::create_anonymous(s))
, m_name(move(n))
, m_readable(r)
, m_writable(w)
, m_cow_map(Bitmap::create(m_vmo->page_count(), cow))
{
m_vmo->set_name(m_name);
MM.register_region(*this);
}
Region::Region(LinearAddress a, size_t s, RetainPtr<Inode>&& inode, String&& n, bool r, bool w)
: m_laddr(a)
, m_size(s)
, m_vmo(VMObject::create_file_backed(move(inode)))
, m_name(move(n))
, m_readable(r)
, m_writable(w)
, m_cow_map(Bitmap::create(m_vmo->page_count()))
{
MM.register_region(*this);
}
Region::Region(LinearAddress a, size_t s, Retained<VMObject>&& vmo, size_t offset_in_vmo, String&& n, bool r, bool w, bool cow)
: m_laddr(a)
, m_size(s)
, m_offset_in_vmo(offset_in_vmo)
, m_vmo(move(vmo))
, m_name(move(n))
, m_readable(r)
, m_writable(w)
, m_cow_map(Bitmap::create(m_vmo->page_count(), cow))
{
MM.register_region(*this);
}
Region::~Region()
{
if (m_page_directory) {
MM.unmap_region(*this);
ASSERT(!m_page_directory);
}
MM.unregister_region(*this);
}
bool Region::page_in()
{
ASSERT(m_page_directory);
ASSERT(!vmo().is_anonymous());
ASSERT(vmo().inode());
#ifdef MM_DEBUG
dbgprintf("MM: page_in %u pages\n", page_count());
#endif
for (size_t i = 0; i < page_count(); ++i) {
auto& vmo_page = vmo().physical_pages()[first_page_index() + i];
if (vmo_page.is_null()) {
bool success = MM.page_in_from_inode(*this, i);
if (!success)
return false;
}
MM.remap_region_page(*this, i, true);
}
return true;
}
Retained<Region> Region::clone()
{
ASSERT(current);
if (m_shared || (m_readable && !m_writable)) {
#ifdef MM_DEBUG
dbgprintf("%s<%u> Region::clone(): sharing %s (L%x)\n",
current->process().name().characters(),
current->pid(),
m_name.characters(),
laddr().get());
#endif
// Create a new region backed by the same VMObject.
return adopt(*new Region(laddr(), size(), m_vmo.copy_ref(), m_offset_in_vmo, String(m_name), m_readable, m_writable));
}
#ifdef MM_DEBUG
dbgprintf("%s<%u> Region::clone(): cowing %s (L%x)\n",
current->process().name().characters(),
current->pid(),
m_name.characters(),
laddr().get());
#endif
// Set up a COW region. The parent (this) region becomes COW as well!
m_cow_map.fill(true);
MM.remap_region(current->process().page_directory(), *this);
return adopt(*new Region(laddr(), size(), m_vmo->clone(), m_offset_in_vmo, String(m_name), m_readable, m_writable, true));
}
int Region::commit()
{
InterruptDisabler disabler;
#ifdef MM_DEBUG
dbgprintf("MM: commit %u pages in Region %p (VMO=%p) at L%x\n", vmo().page_count(), this, &vmo(), laddr().get());
#endif
for (size_t i = first_page_index(); i <= last_page_index(); ++i) {
if (!vmo().physical_pages()[i].is_null())
continue;
auto physical_page = MM.allocate_physical_page(MemoryManager::ShouldZeroFill::Yes);
if (!physical_page) {
kprintf("MM: commit was unable to allocate a physical page\n");
return -ENOMEM;
}
vmo().physical_pages()[i] = move(physical_page);
MM.remap_region_page(*this, i, true);
}
return 0;
}
size_t Region::amount_resident() const
{
size_t bytes = 0;
for (size_t i = 0; i < page_count(); ++i) {
if (m_vmo->physical_pages()[first_page_index() + i])
bytes += PAGE_SIZE;
}
return bytes;
}
size_t Region::amount_shared() const
{
size_t bytes = 0;
for (size_t i = 0; i < page_count(); ++i) {
auto& physical_page = m_vmo->physical_pages()[first_page_index() + i];
if (physical_page && physical_page->retain_count() > 1)
bytes += PAGE_SIZE;
}
return bytes;
}
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