system/dev/bus/pci/root.h

// Copyright 2016 The Fuchsia Authors
// Copyright (c) 2016, Google, Inc. All rights reserved
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#pragma once

#include <fbl/intrusive_wavl_tree.h>
#include <fbl/macros.h>
#include <fbl/ref_ptr.h>
#include <zircon/compiler.h>
#include "upstream_node.h"

namespace pci {
// Forward declaration of Bus to avoid recursive header inclusion between
// bus.h and root.h
class Bus;

class PciRoot : public UpstreamNode {
public:
    // Disallow copying, assigning and moving.
    DISALLOW_COPY_ASSIGN_AND_MOVE(PciRoot);
    virtual ~PciRoot() {}

    // Properties
    PciAllocator& mmio_lo_regions() final { return mmio_lo_regions_; }
    // Prefetch ranges can be allocated from the general mmio allocator
    // without any specific restrictions. There's no distinction between
    // prefetchable and non-prefetchable address space at this point
    // in the upstream allocation chain. This matters for bridges which
    // specifically will need their prefetch devices to be within the
    // prefetch window of upstream bridges.
    PciAllocator& pf_mmio_regions() final { return mmio_hi_regions_; }
    PciAllocator& mmio_hi_regions() final { return mmio_hi_regions_; }
    PciAllocator& pio_regions() final { return pio_regions_; }

protected:
    // PciRootAllocators can be constructed easily because they only need a way
    // to call protocol operations. We set three of them up for the root to use
    // for accessing address space over the pciroot protocol.
    //
    // 1) mmio_lo which tries to get mmio addresses < 4GB
    // 2) mmio_hi which will allocate anywhere in the mmio space
    // 3) pio which will attempt to allocate from the pio allocator
    PciRoot(uint32_t mbus_id, ddk::PcirootProtocolClient* proto)
        : UpstreamNode(UpstreamNode::Type::ROOT, mbus_id),
          mmio_lo_regions_(proto, PCI_ADDRESS_SPACE_MMIO, true),
          mmio_hi_regions_(proto, PCI_ADDRESS_SPACE_MMIO, false),
          pio_regions_(proto, PCI_ADDRESS_SPACE_IO, false) {}

    PciRootAllocator mmio_lo_regions_;
    PciRootAllocator mmio_hi_regions_;
    PciRootAllocator pio_regions_;

    // Only allow the bus driver to instantiate a PciRoot
    friend class Bus;
};

// The PcieRoot derived version exists for support of RCRB (root complex
// register block), but is not implemented yet.
class PcieRoot : public PciRoot {
    PcieRoot(uint32_t managed_bus_id, ddk::PcirootProtocolClient* proto)
        : PciRoot(managed_bus_id, proto){};
    virtual ~PcieRoot() {}
};

} // namespace pci