mirror of
https://github.com/RGBCube/serenity
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8131c0de8c
We want to move this out of the AHCI subsystem into the VM system, since other parts of the kernel may need to perform scatter-gather IO. We rename the current VM::ScatterGatherList impl that's used in the virtio subsystem to VM::ScatterGatherRefList, since its distinguishing feature from the AHCI scatter-gather list is that it doesn't own its buffers.
94 lines
2.3 KiB
C++
94 lines
2.3 KiB
C++
/*
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* Copyright (c) 2021, the SerenityOS developers.
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/Badge.h>
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#include <Kernel/SpinLock.h>
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#include <Kernel/VM/MemoryManager.h>
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#include <Kernel/VM/ScatterGatherList.h>
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namespace Kernel {
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#define VIRTQ_DESC_F_NEXT 1
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#define VIRTQ_DESC_F_INDIRECT 4
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enum class BufferType {
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DeviceReadable = 0,
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DeviceWritable = 2
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};
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class VirtIODevice;
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class VirtIOQueue {
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public:
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VirtIOQueue(u16 queue_size, u16 notify_offset);
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~VirtIOQueue();
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bool is_null() const { return !m_queue_region; }
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u16 notify_offset() const { return m_notify_offset; }
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void enable_interrupts();
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void disable_interrupts();
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PhysicalAddress descriptor_area() const { return to_physical(m_descriptors.ptr()); }
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PhysicalAddress driver_area() const { return to_physical(m_driver.ptr()); }
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PhysicalAddress device_area() const { return to_physical(m_device.ptr()); }
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bool supply_buffer(Badge<VirtIODevice>, const ScatterGatherRefList&, BufferType, void* token);
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bool new_data_available() const;
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bool can_write() const;
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void* get_buffer(size_t*);
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void discard_used_buffers();
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private:
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void pop_buffer(u16 descriptor_index);
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PhysicalAddress to_physical(const void* ptr) const
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{
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auto offset = FlatPtr(ptr) - m_queue_region->vaddr().get();
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return m_queue_region->physical_page(0)->paddr().offset(offset);
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}
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struct [[gnu::packed]] VirtIOQueueDescriptor {
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u64 address;
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u32 length;
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u16 flags;
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u16 next;
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};
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struct [[gnu::packed]] VirtIOQueueDriver {
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u16 flags;
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u16 index;
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u16 rings[];
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};
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struct [[gnu::packed]] VirtIOQueueDeviceItem {
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u32 index;
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u32 length;
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};
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struct [[gnu::packed]] VirtIOQueueDevice {
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u16 flags;
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u16 index;
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VirtIOQueueDeviceItem rings[];
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};
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const u16 m_queue_size;
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const u16 m_notify_offset;
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u16 m_free_buffers;
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u16 m_free_head { 0 };
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u16 m_used_tail { 0 };
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u16 m_driver_index_shadow { 0 };
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OwnPtr<VirtIOQueueDescriptor> m_descriptors { nullptr };
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OwnPtr<VirtIOQueueDriver> m_driver { nullptr };
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OwnPtr<VirtIOQueueDevice> m_device { nullptr };
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Vector<void*> m_tokens;
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OwnPtr<Region> m_queue_region;
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SpinLock<u8> m_lock;
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};
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}
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