Kernel: Add convenience helpers for mapping PCI BAR spaces

This commit is contained in:
Hendiadyoin1 2024-01-11 23:52:29 +01:00 committed by Andrew Kaster
parent 55cd89aea8
commit 2f98c7d470

View file

@ -0,0 +1,71 @@
/*
* Copyright (c) 2024, Leon Albrecht <leon.a@serenityos.org>
* Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/StdLibExtras.h>
#include <Kernel/Bus/PCI/API.h>
#include <Kernel/Memory/TypedMapping.h>
namespace Kernel::PCI {
inline ErrorOr<PhysicalAddress> get_bar_address(DeviceIdentifier const& device, HeaderType0BaseRegister bar)
{
u64 pci_bar_value = get_BAR(device, bar);
auto pci_bar_space_type = get_BAR_space_type(pci_bar_value);
if (pci_bar_space_type == BARSpaceType::IOSpace)
return EIO;
if (pci_bar_space_type == BARSpaceType::Memory64BitSpace) {
// FIXME: In theory, BAR5 cannot be assigned to 64 bit as it is the last one...
// however, there might be 64 bit BAR5 for real bare metal hardware, so remove this
// if it makes a problem.
if (bar == HeaderType0BaseRegister::BAR5) {
return Error::from_errno(EINVAL);
}
u64 next_pci_bar_value = get_BAR(device, static_cast<PCI::HeaderType0BaseRegister>(to_underlying(bar) + 1));
pci_bar_value |= next_pci_bar_value << 32;
return PhysicalAddress { pci_bar_value & bar_address_mask };
}
return PhysicalAddress { pci_bar_value & bar_address_mask };
}
template<typename T>
inline ErrorOr<Memory::TypedMapping<T>> map_bar(DeviceIdentifier const& device, HeaderType0BaseRegister bar, size_t size = sizeof(T), Memory::Region::Access access = IsConst<T> ? Memory::Region::Access::Read : Memory::Region::Access::ReadWrite)
{
u64 pci_bar_value = get_BAR(device, bar);
auto pci_bar_space_type = get_BAR_space_type(pci_bar_value);
if (pci_bar_space_type == PCI::BARSpaceType::IOSpace)
return EIO;
auto bar_address = TRY(get_bar_address(device, bar));
auto pci_bar_space_size = PCI::get_BAR_space_size(device, bar);
if (pci_bar_space_size < size)
return Error::from_errno(EIO);
if (pci_bar_space_type == PCI::BARSpaceType::Memory32BitSpace && Checked<u32>::addition_would_overflow(bar_address.get(), size))
return Error::from_errno(EOVERFLOW);
if (pci_bar_space_type == PCI::BARSpaceType::Memory16BitSpace && Checked<u16>::addition_would_overflow(bar_address.get(), size))
return Error::from_errno(EOVERFLOW);
if (pci_bar_space_type == PCI::BARSpaceType::Memory64BitSpace && Checked<u64>::addition_would_overflow(bar_address.get(), size))
return Error::from_errno(EOVERFLOW);
return Memory::map_typed<T>(bar_address, size, access);
}
template<typename T>
inline ErrorOr<NonnullOwnPtr<Memory::TypedMapping<T>>> adopt_new_nonnull_own_bar_mapping(DeviceIdentifier const& device, HeaderType0BaseRegister bar, size_t size = sizeof(T), Memory::Region::Access access = IsConst<T> ? Memory::Region::Access::Read : Memory::Region::Access::ReadWrite)
{
return adopt_nonnull_own_or_enomem(new (nothrow) Memory::TypedMapping<T>(TRY(map_bar<T>(device, bar, size, access))));
}
}