sdk/banjo/fuchsia.hardware.pciroot/pciroot.fidl

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.hardware.pciroot;
using zx;

type PciBdf = struct {
    bus_id uint8;
    device_id uint8;
    function_id uint8;
};

const DEVICES_PER_BUS uint8 = 64;
const FUNCTIONS_PER_DEVICE uint8 = 8;
const PINS_PER_FUNCTION uint8 = 4;

/// Used to indicate within a routing entry that there is no parent bridge/port
/// device, it is connected directly at the root.
const PCI_IRQ_ROUTING_NO_PARENT uint8 = 0xFF;
/// An entry corresponds to all functions for the given device.
const PCI_IRQ_ROUTING_ALL_FUNCTIONS uint8 = 0xF;

/// A protocol representation of a routing entry.
/// It is intentionally very similar to an ACPI _PRT entry to reduce the complexity of
/// the data structure that needs to be passed over the 'wire'. Endpoints
/// directly connected to a root complex will have port device and function_ids
/// of PCI_IRQ_ROUTING_NO_PARENT. For other endpoints hanging off root ports or
/// bridges their upstream port address will be contained in these fields.
type PciIrqRoutingEntry = struct {
    port_device_id uint8;
    port_function_id uint8;
    device_id uint8;
    pins array<uint8, PINS_PER_FUNCTION>;
};

/// This represents one of the vectors wired up for PCI legacy interrupts. How
/// the bus driver uses them depends on the irq routing table provided to them.
/// The vector is supplied because interrupt objects cannot be inspected with
/// zx_get_object_info.
type PciLegacyIrq = resource struct {
    interrupt zx.handle:INTERRUPT;
    vector uint32;
};

/// This structure is the primary means of passing PCI platform information from
/// the platform bus implementation to the PCI bus driver. If an ecam is found
/// for this segment group then a handle to a VMO for it will be provided via
/// |ecam_vmo|. The VMO's start address will correspond to the base address of
/// the bus number specified by |start_bus_num|.
type PciPlatformInfo = resource struct {
    name string:8;
    start_bus_num uint8;
    end_bus_num uint8;
    segment_group uint16;
    ecam_vmo zx.handle:VMO;
    legacy_irqs vector<PciLegacyIrq>:MAX;
    irq_routing vector<PciIrqRoutingEntry>:MAX;
    /// A vector of PciBdfs that are known to ACPI.
    /// For each BDF in this list, the composite device published by the PCI bus
    /// driver will bind to an ACPI device with ACPI_BUS_TYPE == PCI and a
    /// matching PCI_BIND_TOPO.
    acpi_bdfs vector<PciBdf>:MAX;
};

type PciAddressSpace = strict enum : uint8 {
    MEMORY = 0;
    IO = 0x1;
};

@transport("Banjo")
@banjo_layout("ddk-protocol")
protocol Pciroot {
    /// Legacy methods
    GetBti(struct {
        bdf uint32;
        index uint32;
    }) -> (resource struct {
        s zx.status;
        bti zx.handle:BTI;
    });
    /// Get the platform information structure from the pciroot protocol to be used for bus init.
    GetPciPlatformInfo() -> (resource struct {
        s zx.status;
        info PciPlatformInfo;
    });

    /// Contemporary methods:
    /// Returns true if the bus driver should proxy all device config access to pciroot. This is
    /// necessary in cases of IO config on x86, or for controllers that require configuration to
    /// map in device config headers.
    DriverShouldProxyConfig() -> (struct {
        use_proxy bool;
    });
    /// Read 8 bytes from config space for device at bdf address |address|:we, offset |offset|.
    ReadConfig8(struct {
        address PciBdf;
        offset uint16;
    }) -> (struct {
        s zx.status;
        value uint8;
    });
    /// Read 16 bytes from config space for device at bdf address |address|, offset |offset|.
    ReadConfig16(struct {
        address PciBdf;
        offset uint16;
    }) -> (struct {
        s zx.status;
        value uint16;
    });
    /// Read 32 bytes from config space for device at bdf address |address|, offset |offset|.
    ReadConfig32(struct {
        address PciBdf;
        offset uint16;
    }) -> (struct {
        s zx.status;
        value uint32;
    });
    /// Write 8 bytes to config space for device at bdf |address| offset |offset|.
    WriteConfig8(struct {
        address PciBdf;
        offset uint16;
        value uint8;
    }) -> (struct {
        s zx.status;
    });
    /// Write 16 bytes to config space for device at bdf |address| offset |offset|.
    WriteConfig16(struct {
        address PciBdf;
        offset uint16;
        value uint16;
    }) -> (struct {
        s zx.status;
    });
    /// Write 32 bytes to config space for device at bdf |address| offset |offset|.
    WriteConfig32(struct {
        address PciBdf;
        offset uint16;
        value uint32;
    }) -> (struct {
        s zx.status;
    });
    /// Request address space reservations from platform bus to use for mapping bars / bridges
    /// |in_base| is an optional requested start address which should otherwise be 0. |size| is the
    /// size of the request in bytes. |low| dictates whether the allocation should be an address
    /// below 4 GB or not.
    ///
    /// On success, the base address is provided in |out_base| and the size is |size|.
    ///
    /// An error will be returned if |size| cannot be fulfilled, |low| is set with |in_base|+|size|
    /// being >=4GB, or if a requested |in_base| cannot be provided.
    GetAddressSpace(struct {
        in_base zx.paddr;
        size uint64;
        type PciAddressSpace;
        low bool;
    }) -> (resource struct {
        s zx.status;
        base zx.paddr;
        resource zx.handle:RESOURCE;
        token zx.handle:EVENTPAIR;
    });
    /// Allocate |msi_count| MSIs and return a handle to the backing MsiAllocation.
    AllocateMsi(struct {
        msi_count uint32;
        can_target_64bit bool;
    }) -> (resource struct {
        s zx.status;
        allocation zx.handle:MSI;
    });
};