ladybird/Kernel/Memory/ScatterGatherList.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

31 lines
1.3 KiB
C++

/*
* Copyright (c) 2021, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Memory/ScatterGatherList.h>
namespace Kernel::Memory {
LockRefPtr<ScatterGatherList> ScatterGatherList::try_create(AsyncBlockDeviceRequest& request, Span<NonnullRefPtr<PhysicalPage>> allocated_pages, size_t device_block_size)
{
auto maybe_vm_object = AnonymousVMObject::try_create_with_physical_pages(allocated_pages);
if (maybe_vm_object.is_error()) {
// FIXME: Would be nice to be able to return a ErrorOr here.
return {};
}
return adopt_lock_ref_if_nonnull(new (nothrow) ScatterGatherList(maybe_vm_object.release_value(), request, device_block_size));
}
ScatterGatherList::ScatterGatherList(NonnullLockRefPtr<AnonymousVMObject> vm_object, AsyncBlockDeviceRequest& request, size_t device_block_size)
: m_vm_object(move(vm_object))
{
auto region_or_error = MM.allocate_kernel_region_with_vmobject(m_vm_object, page_round_up((request.block_count() * device_block_size)).release_value_but_fixme_should_propagate_errors(), "AHCI Scattered DMA"sv, Region::Access::Read | Region::Access::Write, Region::Cacheable::Yes);
if (region_or_error.is_error())
TODO();
m_dma_region = region_or_error.release_value();
}
}