ladybird/Kernel/Memory/SharedFramebufferVMObject.cpp
Andreas Kling 2c72d495a3 Kernel: Use RefPtr instead of LockRefPtr for PhysicalPage
I believe this to be safe, as the main thing that LockRefPtr provides
over RefPtr is safe copying from a shared LockRefPtr instance. I've
inspected the uses of RefPtr<PhysicalPage> and it seems they're all
guarded by external locking. Some of it is less obvious, but this is
an area where we're making continuous headway.
2022-08-24 18:35:41 +02:00

120 lines
5.2 KiB
C++

/*
* Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/Locking/Spinlock.h>
#include <Kernel/Memory/SharedFramebufferVMObject.h>
namespace Kernel::Memory {
ErrorOr<NonnullLockRefPtr<SharedFramebufferVMObject>> SharedFramebufferVMObject::try_create_for_physical_range(PhysicalAddress paddr, size_t size)
{
auto real_framebuffer_vmobject = TRY(AnonymousVMObject::try_create_for_physical_range(paddr, size));
auto new_physical_pages = TRY(VMObject::try_create_physical_pages(size));
auto committed_pages = TRY(MM.commit_physical_pages(ceil_div(size, static_cast<size_t>(PAGE_SIZE))));
auto vm_object = TRY(adopt_nonnull_lock_ref_or_enomem(new (nothrow) SharedFramebufferVMObject(move(new_physical_pages), move(committed_pages), real_framebuffer_vmobject)));
TRY(vm_object->create_fake_writes_framebuffer_vm_object());
TRY(vm_object->create_real_writes_framebuffer_vm_object());
return vm_object;
}
ErrorOr<NonnullLockRefPtr<SharedFramebufferVMObject>> SharedFramebufferVMObject::try_create_at_arbitrary_physical_range(size_t size)
{
auto real_framebuffer_vmobject = TRY(AnonymousVMObject::try_create_with_size(size, AllocationStrategy::AllocateNow));
auto new_physical_pages = TRY(VMObject::try_create_physical_pages(size));
auto committed_pages = TRY(MM.commit_physical_pages(ceil_div(size, static_cast<size_t>(PAGE_SIZE))));
auto vm_object = TRY(adopt_nonnull_lock_ref_or_enomem(new (nothrow) SharedFramebufferVMObject(move(new_physical_pages), move(committed_pages), real_framebuffer_vmobject)));
TRY(vm_object->create_fake_writes_framebuffer_vm_object());
TRY(vm_object->create_real_writes_framebuffer_vm_object());
return vm_object;
}
ErrorOr<NonnullLockRefPtr<SharedFramebufferVMObject::FakeWritesFramebufferVMObject>> SharedFramebufferVMObject::FakeWritesFramebufferVMObject::try_create(Badge<SharedFramebufferVMObject>, SharedFramebufferVMObject const& parent_object)
{
auto new_physical_pages = TRY(VMObject::try_create_physical_pages(0));
return adopt_nonnull_lock_ref_or_enomem(new (nothrow) FakeWritesFramebufferVMObject(parent_object, move(new_physical_pages)));
}
ErrorOr<NonnullLockRefPtr<SharedFramebufferVMObject::RealWritesFramebufferVMObject>> SharedFramebufferVMObject::RealWritesFramebufferVMObject::try_create(Badge<SharedFramebufferVMObject>, SharedFramebufferVMObject const& parent_object)
{
auto new_physical_pages = TRY(VMObject::try_create_physical_pages(0));
return adopt_nonnull_lock_ref_or_enomem(new (nothrow) RealWritesFramebufferVMObject(parent_object, move(new_physical_pages)));
}
ErrorOr<void> SharedFramebufferVMObject::create_fake_writes_framebuffer_vm_object()
{
m_fake_writes_framebuffer_vmobject = TRY(FakeWritesFramebufferVMObject::try_create({}, *this));
return {};
}
ErrorOr<void> SharedFramebufferVMObject::create_real_writes_framebuffer_vm_object()
{
m_real_writes_framebuffer_vmobject = TRY(RealWritesFramebufferVMObject::try_create({}, *this));
return {};
}
Span<RefPtr<PhysicalPage>> SharedFramebufferVMObject::real_framebuffer_physical_pages()
{
return m_real_framebuffer_vmobject->physical_pages();
}
Span<RefPtr<PhysicalPage> const> SharedFramebufferVMObject::real_framebuffer_physical_pages() const
{
return m_real_framebuffer_vmobject->physical_pages();
}
Span<RefPtr<PhysicalPage>> SharedFramebufferVMObject::fake_sink_framebuffer_physical_pages()
{
return m_physical_pages.span();
}
Span<RefPtr<PhysicalPage> const> SharedFramebufferVMObject::fake_sink_framebuffer_physical_pages() const
{
return m_physical_pages.span();
}
void SharedFramebufferVMObject::switch_to_fake_sink_framebuffer_writes(Badge<Kernel::DisplayConnector>)
{
SpinlockLocker locker(m_writes_state_lock);
m_writes_are_faked = true;
for_each_region([](Region& region) {
region.remap();
});
}
void SharedFramebufferVMObject::switch_to_real_framebuffer_writes(Badge<Kernel::DisplayConnector>)
{
SpinlockLocker locker(m_writes_state_lock);
m_writes_are_faked = false;
for_each_region([](Region& region) {
region.remap();
});
}
Span<RefPtr<PhysicalPage> const> SharedFramebufferVMObject::physical_pages() const
{
SpinlockLocker locker(m_writes_state_lock);
if (m_writes_are_faked)
return VMObject::physical_pages();
return m_real_framebuffer_vmobject->physical_pages();
}
Span<RefPtr<PhysicalPage>> SharedFramebufferVMObject::physical_pages()
{
SpinlockLocker locker(m_writes_state_lock);
if (m_writes_are_faked)
return VMObject::physical_pages();
return m_real_framebuffer_vmobject->physical_pages();
}
SharedFramebufferVMObject::SharedFramebufferVMObject(FixedArray<RefPtr<PhysicalPage>>&& new_physical_pages, CommittedPhysicalPageSet committed_pages, AnonymousVMObject& real_framebuffer_vmobject)
: VMObject(move(new_physical_pages))
, m_real_framebuffer_vmobject(real_framebuffer_vmobject)
, m_committed_pages(move(committed_pages))
{
// Allocate all pages right now. We know we can get all because we committed the amount needed
for (size_t i = 0; i < page_count(); ++i)
m_physical_pages[i] = m_committed_pages.take_one();
}
}