mirror of
https://github.com/RGBCube/serenity
synced 2025-10-31 11:12:45 +00:00
7718842829
Simplify core methods in the VirtIO bus handling code by ensuring proper error propagation. This makes initialization of queues, handling changes in device configuration, and other core patterns more readable as well. It also allows us to remove the obnoxious pattern of checking for boolean "success" and if we get false answer then returning an actual errno code.
75 lines
2.4 KiB
C++
75 lines
2.4 KiB
C++
/*
|
|
* Copyright (c) 2021, the SerenityOS developers.
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <Kernel/Bus/VirtIO/RNG.h>
|
|
#include <Kernel/Bus/VirtIO/Transport/PCIe/TransportLink.h>
|
|
#include <Kernel/Sections.h>
|
|
|
|
namespace Kernel::VirtIO {
|
|
|
|
UNMAP_AFTER_INIT NonnullLockRefPtr<RNG> RNG::must_create_for_pci_instance(PCI::DeviceIdentifier const& device_identifier)
|
|
{
|
|
auto pci_transport_link = MUST(PCIeTransportLink::create(device_identifier));
|
|
return adopt_lock_ref_if_nonnull(new RNG(move(pci_transport_link))).release_nonnull();
|
|
}
|
|
|
|
UNMAP_AFTER_INIT ErrorOr<void> RNG::initialize_virtio_resources()
|
|
{
|
|
TRY(Device::initialize_virtio_resources());
|
|
TRY(negotiate_features([&](auto) {
|
|
return 0;
|
|
}));
|
|
TRY(setup_queues(1));
|
|
finish_init();
|
|
m_entropy_buffer = TRY(MM.allocate_contiguous_kernel_region(PAGE_SIZE, "VirtIO::RNG"sv, Memory::Region::Access::ReadWrite));
|
|
memset(m_entropy_buffer->vaddr().as_ptr(), 0, m_entropy_buffer->size());
|
|
request_entropy_from_host();
|
|
return {};
|
|
}
|
|
|
|
UNMAP_AFTER_INIT RNG::RNG(NonnullOwnPtr<TransportEntity> transport_entity)
|
|
: VirtIO::Device(move(transport_entity))
|
|
{
|
|
}
|
|
|
|
ErrorOr<void> RNG::handle_device_config_change()
|
|
{
|
|
return Error::from_errno(EIO); // Device has no config
|
|
}
|
|
|
|
void RNG::handle_queue_update(u16 queue_index)
|
|
{
|
|
VERIFY(queue_index == REQUESTQ);
|
|
size_t available_entropy = 0, used;
|
|
auto& queue = get_queue(REQUESTQ);
|
|
{
|
|
SpinlockLocker lock(queue.lock());
|
|
auto chain = queue.pop_used_buffer_chain(used);
|
|
if (chain.is_empty())
|
|
return;
|
|
VERIFY(chain.length() == 1);
|
|
chain.for_each([&available_entropy](PhysicalAddress, size_t length) {
|
|
available_entropy = length;
|
|
});
|
|
chain.release_buffer_slots_to_queue();
|
|
}
|
|
dbgln_if(VIRTIO_DEBUG, "VirtIO::RNG: received {} bytes of entropy!", available_entropy);
|
|
for (auto i = 0u; i < available_entropy; i++) {
|
|
m_entropy_source.add_random_event(m_entropy_buffer->vaddr().as_ptr()[i]);
|
|
}
|
|
// TODO: When should we get some more entropy?
|
|
}
|
|
|
|
void RNG::request_entropy_from_host()
|
|
{
|
|
auto& queue = get_queue(REQUESTQ);
|
|
SpinlockLocker lock(queue.lock());
|
|
QueueChain chain(queue);
|
|
chain.add_buffer_to_chain(m_entropy_buffer->physical_page(0)->paddr(), PAGE_SIZE, BufferType::DeviceWritable);
|
|
supply_chain_and_notify(REQUESTQ, chain);
|
|
}
|
|
|
|
}
|