Files
ladybird/Kernel/VirtIO/VirtIOQueue.cpp
Idan Horowitz 42b1eb5af1 Kernel: Activate queues and enable interrutps in VirtIODevices
This patch actually enables virtio queues after configuring them
so the device can use them, it also enables interrupt handling in
VirtIODevice so they are not ignored.

Co-authored-by: Sahan <sahan.h.fernando@gmail.com>
2021-04-17 10:21:23 +02:00

107 lines
3.7 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <Kernel/StdLib.h>
#include <Kernel/VirtIO/VirtIOQueue.h>
namespace Kernel {
VirtIOQueue::VirtIOQueue(u16 queue_size, u16 notify_offset)
: m_queue_size(queue_size)
, m_notify_offset(notify_offset)
, m_free_buffers(queue_size)
{
size_t size_of_descriptors = sizeof(VirtIOQueueDescriptor) * queue_size;
size_t size_of_driver = sizeof(VirtIOQueueDriver) + queue_size * sizeof(u16);
size_t size_of_device = sizeof(VirtIOQueueDevice) + queue_size * sizeof(VirtIOQueueDeviceItem);
m_region = MM.allocate_contiguous_kernel_region(page_round_up(size_of_descriptors + size_of_driver + size_of_device), "VirtIO Queue", Region::Access::Read | Region::Access::Write);
if (m_region) {
// TODO: ensure alignment!!!
u8* ptr = m_region->vaddr().as_ptr();
memset(ptr, 0, m_region->size());
m_descriptors = reinterpret_cast<VirtIOQueueDescriptor*>(ptr);
m_driver = reinterpret_cast<VirtIOQueueDriver*>(ptr + size_of_descriptors);
m_device = reinterpret_cast<VirtIOQueueDevice*>(ptr + size_of_descriptors + size_of_driver);
enable_interrupts();
}
}
VirtIOQueue::~VirtIOQueue()
{
}
void VirtIOQueue::enable_interrupts()
{
m_driver->flags = 0;
}
void VirtIOQueue::disable_interrupts()
{
m_driver->flags = 1;
}
bool VirtIOQueue::supply_buffer(const u8* buffer, u32 len, BufferType buffer_type)
{
VERIFY(buffer && len > 0);
VERIFY(m_free_buffers > 0);
auto descriptor_index = m_free_head;
m_descriptors[descriptor_index].flags = static_cast<u16>(buffer_type);
m_descriptors[descriptor_index].address = reinterpret_cast<u64>(buffer);
m_descriptors[descriptor_index].length = len;
m_free_buffers--;
m_free_head = (m_free_head + 1) % m_queue_size;
m_driver->rings[m_driver_index_shadow % m_queue_size] = descriptor_index; // m_driver_index_shadow is used to prevent accesses to index before the rings are updated
full_memory_barrier();
m_driver_index_shadow++;
m_driver->index++;
full_memory_barrier();
auto device_flags = m_device->flags;
return !(device_flags & 1); // if bit 1 is enabled the device disabled interrupts
}
bool VirtIOQueue::new_data_available() const
{
return m_device->index != m_used_tail;
}
bool VirtIOQueue::handle_interrupt()
{
if (!new_data_available())
return false;
if (on_data_available)
on_data_available();
return true;
}
}