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https://github.com/RGBCube/serenity
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ecfa7cb824
This patch allocates a physical page for each of the virtqueues and memcpys to it when receiving a buffer to get a physical, aligned contiguous buffer as required by the virtio specification. Co-authored-by: Sahan <sahan.h.fernando@gmail.com>
106 lines
3.8 KiB
C++
106 lines
3.8 KiB
C++
/*
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* Copyright (c) 2020, the SerenityOS developers.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <Kernel/StdLib.h>
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#include <Kernel/VirtIO/VirtIOQueue.h>
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namespace Kernel {
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VirtIOQueue::VirtIOQueue(u16 queue_size, u16 notify_offset)
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: m_queue_size(queue_size)
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, m_notify_offset(notify_offset)
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, m_free_buffers(queue_size)
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{
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size_t size_of_descriptors = sizeof(VirtIOQueueDescriptor) * queue_size;
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size_t size_of_driver = sizeof(VirtIOQueueDriver) + queue_size * sizeof(u16);
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size_t size_of_device = sizeof(VirtIOQueueDevice) + queue_size * sizeof(VirtIOQueueDeviceItem);
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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);
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if (m_region) {
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// TODO: ensure alignment!!!
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u8* ptr = m_region->vaddr().as_ptr();
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memset(ptr, 0, m_region->size());
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m_descriptors = reinterpret_cast<VirtIOQueueDescriptor*>(ptr);
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m_driver = reinterpret_cast<VirtIOQueueDriver*>(ptr + size_of_descriptors);
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m_device = reinterpret_cast<VirtIOQueueDevice*>(ptr + size_of_descriptors + size_of_driver);
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enable_interrupts();
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}
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}
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VirtIOQueue::~VirtIOQueue()
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{
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}
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void VirtIOQueue::enable_interrupts()
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{
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m_driver->flags = 0;
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}
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void VirtIOQueue::disable_interrupts()
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{
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m_driver->flags = 1;
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}
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bool VirtIOQueue::supply_buffer(Badge<VirtIODevice>, const u8* buffer, u32 length, BufferType buffer_type)
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{
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VERIFY(buffer && length > 0);
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VERIFY(m_free_buffers > 0);
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auto descriptor_index = m_free_head;
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m_descriptors[descriptor_index].flags = static_cast<u16>(buffer_type);
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m_descriptors[descriptor_index].address = reinterpret_cast<u64>(buffer);
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m_descriptors[descriptor_index].length = length;
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m_free_buffers--;
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m_free_head = (m_free_head + 1) % m_queue_size;
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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
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full_memory_barrier();
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m_driver_index_shadow++;
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m_driver->index++;
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full_memory_barrier();
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auto device_flags = m_device->flags;
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return !(device_flags & 1); // if bit 1 is enabled the device disabled interrupts
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}
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bool VirtIOQueue::new_data_available() const
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{
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return m_device->index != m_used_tail;
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}
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bool VirtIOQueue::handle_interrupt()
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{
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if (!new_data_available())
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return false;
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if (on_data_available)
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on_data_available();
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return true;
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}
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}
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