ladybird/Kernel/PCI/MMIOAccess.h
Liav A 8abbb7e090 Kernel/PCI: Introduce a new ECAM access mechanism
Now the kernel supports 2 ECAM access methods.
MMIOAccess was renamed to WindowedMMIOAccess and is what we had until
now - each device that is detected on boot is assigned to a
memory-mapped window, so IO operations on multiple devices can occur
simultaneously due to creating multiple virtual mappings, hence the name
is a memory-mapped window.

This commit adds a new class called MMIOAccess (not to be confused with
the old MMIOAccess class). This class creates one memory-mapped window.
On each IO operation on a configuration space of a device, it maps the
requested PCI bus region to that window. Therefore it holds a SpinLock
during the operation to ensure that no other PCI bus region was mapped
during the call.

A user can choose to either use PCI ECAM with memory-mapped window
for each device, or for an entire bus. By default, the kernel prefers to
map the entire PCI bus region.
2021-04-03 19:34:52 +02:00

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3.3 KiB
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/*
* Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
* 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/HashMap.h>
#include <AK/NonnullOwnPtrVector.h>
#include <AK/OwnPtr.h>
#include <AK/Types.h>
#include <Kernel/ACPI/Definitions.h>
#include <Kernel/PCI/Access.h>
#include <Kernel/SpinLock.h>
#include <Kernel/VM/AnonymousVMObject.h>
#include <Kernel/VM/PhysicalRegion.h>
#include <Kernel/VM/Region.h>
#include <Kernel/VM/VMObject.h>
namespace Kernel {
namespace PCI {
#define PCI_MMIO_CONFIG_SPACE_SIZE 4096
class MMIOAccess : public Access {
public:
class MMIOSegment {
public:
MMIOSegment(PhysicalAddress, u8, u8);
u8 get_start_bus() const;
u8 get_end_bus() const;
size_t get_size() const;
PhysicalAddress get_paddr() const;
private:
PhysicalAddress m_base_addr;
u8 m_start_bus;
u8 m_end_bus;
};
static void initialize(PhysicalAddress mcfg);
private:
PhysicalAddress determine_memory_mapped_bus_region(u32 segment, u8 bus) const;
void map_bus_region(u32, u8);
VirtualAddress get_device_configuration_space(Address address);
SpinLock<u8> m_access_lock;
u8 m_mapped_bus { 0 };
OwnPtr<Region> m_mapped_region;
protected:
explicit MMIOAccess(PhysicalAddress mcfg);
virtual const char* access_type() const override { return "MMIOAccess"; };
virtual u32 segment_count() const override;
virtual void enumerate_hardware(Function<void(Address, ID)>) override;
virtual void write8_field(Address address, u32, u8) override;
virtual void write16_field(Address address, u32, u16) override;
virtual void write32_field(Address address, u32, u32) override;
virtual u8 read8_field(Address address, u32) override;
virtual u16 read16_field(Address address, u32) override;
virtual u32 read32_field(Address address, u32) override;
virtual u8 segment_start_bus(u32) const override;
virtual u8 segment_end_bus(u32) const override;
PhysicalAddress m_mcfg;
HashMap<u16, MMIOSegment> m_segments;
};
}
}