mirror of
https://github.com/fergalmoran/ladybird.git
synced 2026-01-04 15:45:25 +00:00
d1f7a2f9a5
This commit includes a lot of small changes and additions needed to finalize the base implementation of VirtIOQueues and VirtDevices: * The device specific driver implementation now has to handle setting up the queues it needs before letting the base device class know it finised initialization * Supplying buffers to VirtQueues is now done via ScatterGatherLists instead of arbitary buffer pointers - this ensures the pointers are physical and allows us to follow the specification in regards to the requirement that individual descriptors must point to physically contiguous buffers. This can be further improved in the future by implementating support for the Indirect-Descriptors feature (as defined by the specification) to reduce descriptor usage for very fragmented buffers. * When supplying buffers to a VirtQueue the driver must supply a (temporarily-)unique token (usually the supplied buffer's virtual address) to ensure the driver can discern which buffer has finished processing by the device in the case in which the device does not offer the F_IN_ORDER feature. * Device drivers now handle queue updates (supplied buffers being returned from the device) by implementing a single pure virtual method instead of setting a seperate callback for each queue * Two new VirtQueue methods were added to allow the device driver to either discard or get used/returned buffers from the device by cleanly removing them off the descriptor chain (This also allows the VirtQueue implementation to reuse those freed descriptors) This also includes the necessary changes to the VirtIOConsole implementation to match these interface changes. Co-authored-by: Sahan <sahan.h.fernando@gmail.com>
114 lines
3.5 KiB
C++
114 lines
3.5 KiB
C++
/*
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* Copyright (c) 2021, 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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#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 ScatterGatherList&, BufferType, void* token);
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bool new_data_available() 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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