ladybird/Kernel/VirtIO/VirtIOQueue.h

115 lines
3.5 KiB
C++

/*
* Copyright (c) 2021, 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.
*/
#pragma once
#include <AK/Badge.h>
#include <Kernel/SpinLock.h>
#include <Kernel/VM/MemoryManager.h>
#include <Kernel/VM/ScatterGatherList.h>
namespace Kernel {
#define VIRTQ_DESC_F_NEXT 1
#define VIRTQ_DESC_F_INDIRECT 4
enum class BufferType {
DeviceReadable = 0,
DeviceWritable = 2
};
class VirtIODevice;
class VirtIOQueue {
public:
VirtIOQueue(u16 queue_size, u16 notify_offset);
~VirtIOQueue();
bool is_null() const { return !m_queue_region; }
u16 notify_offset() const { return m_notify_offset; }
void enable_interrupts();
void disable_interrupts();
PhysicalAddress descriptor_area() const { return to_physical(m_descriptors.ptr()); }
PhysicalAddress driver_area() const { return to_physical(m_driver.ptr()); }
PhysicalAddress device_area() const { return to_physical(m_device.ptr()); }
bool supply_buffer(Badge<VirtIODevice>, const ScatterGatherList&, BufferType, void* token);
bool new_data_available() const;
bool can_write() const;
void* get_buffer(size_t*);
void discard_used_buffers();
private:
void pop_buffer(u16 descriptor_index);
PhysicalAddress to_physical(const void* ptr) const
{
auto offset = FlatPtr(ptr) - m_queue_region->vaddr().get();
return m_queue_region->physical_page(0)->paddr().offset(offset);
}
struct [[gnu::packed]] VirtIOQueueDescriptor {
u64 address;
u32 length;
u16 flags;
u16 next;
};
struct [[gnu::packed]] VirtIOQueueDriver {
u16 flags;
u16 index;
u16 rings[];
};
struct [[gnu::packed]] VirtIOQueueDeviceItem {
u32 index;
u32 length;
};
struct [[gnu::packed]] VirtIOQueueDevice {
u16 flags;
u16 index;
VirtIOQueueDeviceItem rings[];
};
const u16 m_queue_size;
const u16 m_notify_offset;
u16 m_free_buffers;
u16 m_free_head { 0 };
u16 m_used_tail { 0 };
u16 m_driver_index_shadow { 0 };
OwnPtr<VirtIOQueueDescriptor> m_descriptors { nullptr };
OwnPtr<VirtIOQueueDriver> m_driver { nullptr };
OwnPtr<VirtIOQueueDevice> m_device { nullptr };
Vector<void*> m_tokens;
OwnPtr<Region> m_queue_region;
SpinLock<u8> m_lock;
};
}