nextpnr/mistral/arch.h

/*
 *  nextpnr -- Next Generation Place and Route
 *
 *  Copyright (C) 2021  Lofty <dan.ravensloft@gmail.com>
 *
 *  Permission to use, copy, modify, and/or distribute this software for any
 *  purpose with or without fee is hereby granted, provided that the above
 *  copyright notice and this permission notice appear in all copies.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#ifndef MISTRAL_ARCH_H
#define MISTRAL_ARCH_H

#include <set>
#include <sstream>

#include "base_arch.h"
#include "nextpnr_types.h"
#include "relptr.h"

#include "cyclonev.h"

NEXTPNR_NAMESPACE_BEGIN

struct ArchArgs
{
    std::string device;
};

// These structures are used for fast ALM validity checking
struct ALMInfo
{
    // Wires, so bitstream gen can determine connectivity
    std::array<WireId, 2> comb_out;
    std::array<WireId, 2> sel_clk, sel_ena, sel_aclr, sel_ef;
    std::array<WireId, 4> ff_in, ff_out;
    // Pointers to bels
    std::array<BelId, 2> lut_bels;
    std::array<BelId, 4> ff_bels;

    bool l6_mode = false;
    bool carry_mode = false;

    // Which CLK/ENA and ACLR is chosen for each half
    std::array<int, 2> clk_ena_idx, aclr_idx;

    // For keeping track of how many inputs are currently being used, for the LAB routeability check
    int unique_input_count = 0;
};

struct LABInfo
{
    // LAB or MLAB?
    bool is_mlab;
    std::array<ALMInfo, 10> alms;
    //  Control set wires
    std::array<WireId, 3> clk_wires, ena_wires;
    std::array<WireId, 2> aclr_wires;
    WireId sclr_wire, sload_wire;
    // TODO: LAB configuration (control set etc)
    std::array<bool, 2> aclr_used;
};

struct PinInfo
{
    WireId wire;
    PortType dir;
};

struct BelInfo
{
    IdString name;
    IdString type;
    IdString bucket;

    CellInfo *bound = nullptr;

    // For cases where we need to determine an original block index, due to multiple bels at the same tile this
    // might not be the same as the nextpnr z-coordinate
    int block_index;
    dict<IdString, PinInfo> pins;
    // Info for different kinds of bels
    union
    {
        // This enables fast lookup of the associated ALM, etc
        struct
        {
            uint32_t lab; // index into the list of LABs
            uint8_t alm;  // ALM index inside LAB
            uint8_t idx;  // LUT or FF index inside ALM
        } lab_data;
    };
};

// We maintain our own wire data based on mistral's. This gets us the bidirectional linking that nextpnr needs,
// and also makes it easy to add wires and pips for our own purposes like LAB internal routing, global clock
// sources, etc.
struct WireInfo
{
    // name_override is only used for nextpnr-created wires
    // otherwise; this is empty and a name is created according to mistral rules
    IdString name_override;

    // these are transformed on-the-fly to PipId by the iterator, to save space (WireId is half the size of PipId)
    std::vector<WireId> wires_downhill;
    std::vector<WireId> wires_uphill;

    std::vector<BelPin> bel_pins;

    // flags for special wires (currently unused)
    uint64_t flags;

    // if the RESERVED_ROUTE mask is set in flags, then only wires_uphill[flags&0xFF] may drive this wire - used for
    // control set preallocations
    static const uint64_t RESERVED_ROUTE = 0x100;
};

// This transforms a WireIds, and adds the mising half of the pair to create a PipId
using WireVecIterator = std::vector<WireId>::const_iterator;
struct UpDownhillPipIterator
{
    WireVecIterator base;
    WireId other_wire;
    bool is_uphill;

    UpDownhillPipIterator(WireVecIterator base, WireId other_wire, bool is_uphill)
            : base(base), other_wire(other_wire), is_uphill(is_uphill) {};

    bool operator!=(const UpDownhillPipIterator &other) { return base != other.base; }
    UpDownhillPipIterator operator++()
    {
        ++base;
        return *this;
    }
    UpDownhillPipIterator operator++(int)
    {
        UpDownhillPipIterator prior(*this);
        ++(*this);
        return prior;
    }
    PipId operator*() { return is_uphill ? PipId(base->node, other_wire.node) : PipId(other_wire.node, base->node); }
};

struct UpDownhillPipRange
{
    UpDownhillPipIterator b, e;

    UpDownhillPipRange(const std::vector<WireId> &v, WireId other_wire, bool is_uphill)
            : b(v.begin(), other_wire, is_uphill), e(v.end(), other_wire, is_uphill) {};

    UpDownhillPipIterator begin() const { return b; }
    UpDownhillPipIterator end() const { return e; }
};

// This iterates over the list of wires, and for each wire yields its uphill pips, as an efficient way of going over
// all the pips in the device
using WireMapIterator = dict<WireId, WireInfo>::const_iterator;
struct AllPipIterator
{
    WireMapIterator base, end;
    int uphill_idx;

    AllPipIterator(WireMapIterator base, WireMapIterator end, int uphill_idx)
            : base(base), end(end), uphill_idx(uphill_idx) {};

    bool operator!=(const AllPipIterator &other) { return base != other.base || uphill_idx != other.uphill_idx; }
    AllPipIterator operator++()
    {
        // Increment uphill list index by one
        ++uphill_idx;
        // We've reached the end of the current wire. Keep incrementing the wire of interest until we find one with
        // uphill pips, or we reach the end of the list of wires
        while (base != end && uphill_idx >= int(base->second.wires_uphill.size())) {
            uphill_idx = 0;
            ++base;
        }
        return *this;
    }
    AllPipIterator operator++(int)
    {
        AllPipIterator prior(*this);
        ++(*this);
        return prior;
    }
    PipId operator*() { return PipId(base->second.wires_uphill.at(uphill_idx).node, base->first.node); }
};

struct AllPipRange
{
    AllPipIterator b, e;

    AllPipRange(const dict<WireId, WireInfo> &wires) : b(wires.begin(), wires.end(), -1), e(wires.end(), wires.end(), 0)
    {
        // Starting the begin iterator at index -1 and incrementing it ensures we skip over the first wire if it has no
        // uphill pips
        ++b;
    };

    AllPipIterator begin() const { return b; }
    AllPipIterator end() const { return e; }
};

// This transforms a map to a range of keys, used as the wire iterator
template <typename T> struct key_range
{
    key_range(const T &t) : b(t.begin()), e(t.end()) {};
    typename T::const_iterator b, e;

    struct xformed_iterator : public T::const_iterator
    {
        explicit xformed_iterator(typename T::const_iterator base) : T::const_iterator(base) {};
        typename T::key_type operator*() { return this->T::const_iterator::operator*().first; }
    };

    xformed_iterator begin() const { return xformed_iterator(b); }
    xformed_iterator end() const { return xformed_iterator(e); }
};

using AllWireRange = key_range<dict<WireId, WireInfo>>;

struct ArchRanges : BaseArchRanges
{
    using ArchArgsT = ArchArgs;
    // Bels
    using AllBelsRangeT = const std::vector<BelId> &;
    using TileBelsRangeT = std::vector<BelId>;
    using BelPinsRangeT = std::vector<IdString>;
    using CellBelPinRangeT = const std::vector<IdString> &;
    // Wires
    using AllWiresRangeT = AllWireRange;
    using DownhillPipRangeT = UpDownhillPipRange;
    using UphillPipRangeT = UpDownhillPipRange;
    using WireBelPinRangeT = const std::vector<BelPin> &;
    // Pips
    using AllPipsRangeT = AllPipRange;
};

// This enum captures different 'styles' of cell pins
// This is a combination of the modes available for a pin (tied high, low or inverted)
// and the default value to set it to not connected
enum CellPinStyle
{
    PINOPT_NONE = 0x0, // no options, just signal as-is
    PINOPT_LO = 0x1,   // can be tied low
    PINOPT_HI = 0x2,   // can be tied high
    PINOPT_INV = 0x4,  // can be inverted

    PINOPT_LOHI = 0x3,    // can be tied low or high
    PINOPT_LOHIINV = 0x7, // can be tied low or high; or inverted

    PINOPT_MASK = 0x7,

    PINDEF_NONE = 0x00, // leave disconnected
    PINDEF_0 = 0x10,    // connect to 0 if not used
    PINDEF_1 = 0x20,    // connect to 1 if not used

    PINDEF_MASK = 0x30,

    PINGLB_CLK = 0x100, // pin is a 'clock' for global purposes

    PINGLB_MASK = 0x100,

    PINSTYLE_NONE = 0x000, // default

    PINSTYLE_COMB = 0x017, // combinational signal, defaults low, can be inverted and tied
    PINSTYLE_CLK = 0x107,  // CLK type signal, invertible and defaults to disconnected

    PINSTYLE_CE = 0x027,   // CE type signal, invertible and defaults to enabled
    PINSTYLE_RST = 0x017,  // RST type signal, invertible and defaults to not reset
    PINSTYLE_DEDI = 0x000, // dedicated signals, leave alone
    PINSTYLE_INP = 0x001,  // general inputs, no inversion/tieing but defaults low
    PINSTYLE_PU = 0x022,   // signals that float high and default high

    PINSTYLE_CARRY = 0x001, // carry chains can be floating or 0?

};

struct Arch : BaseArch<ArchRanges>
{
    ArchArgs args;
    mistral::CycloneV *cyclonev;

    // Mistral needs the bitstream configuring before it can use the simulator.
    bool bitstream_configured = false;

    Arch(ArchArgs args);
    ArchArgs archArgs() const override { return args; }

    std::string getChipName() const override { return args.device; }
    // -------------------------------------------------

    int getGridDimX() const override { return cyclonev->get_tile_sx(); }
    int getGridDimY() const override { return cyclonev->get_tile_sy(); }
    int getTileBelDimZ(int x, int y) const override; // arch.cc
    char getNameDelimiter() const override { return '.'; }

    // -------------------------------------------------

    BelId getBelByName(IdStringList name) const override; // arch.cc
    IdStringList getBelName(BelId bel) const override;    // arch.cc
    const std::vector<BelId> &getBels() const override { return all_bels; }
    std::vector<BelId> getBelsByTile(int x, int y) const override;
    Loc getBelLocation(BelId bel) const override
    {
        return Loc(CycloneV::pos2x(bel.pos), CycloneV::pos2y(bel.pos), bel.z);
    }
    BelId getBelByLocation(Loc loc) const override
    {
        if (loc.x < 0 || loc.x >= cyclonev->get_tile_sx())
            return BelId();
        if (loc.y < 0 || loc.y >= cyclonev->get_tile_sy())
            return BelId();
        auto &bels = bels_by_tile.at(pos2idx(loc.x, loc.y));
        if (loc.z < 0 || loc.z >= int(bels.size()))
            return BelId();
        return BelId(CycloneV::xy2pos(loc.x, loc.y), loc.z);
    }
    IdString getBelType(BelId bel) const override; // arch.cc
    WireId getBelPinWire(BelId bel, IdString pin) const override
    {
        auto &pins = bel_data(bel).pins;
        auto found = pins.find(pin);
        if (found == pins.end())
            return WireId();
        else
            return found->second.wire;
    }
    PortType getBelPinType(BelId bel, IdString pin) const override { return bel_data(bel).pins.at(pin).dir; }
    std::vector<IdString> getBelPins(BelId bel) const override;

    bool isBelLocationValid(BelId bel, bool explain_invalid = false) const override;

    void bindBel(BelId bel, CellInfo *cell, PlaceStrength strength) override
    {
        auto &data = bel_data(bel);
        NPNR_ASSERT(data.bound == nullptr);
        data.bound = cell;
        cell->bel = bel;
        cell->belStrength = strength;
        update_bel(bel);
    }
    void unbindBel(BelId bel) override
    {
        auto &data = bel_data(bel);
        NPNR_ASSERT(data.bound != nullptr);
        data.bound->bel = BelId();
        data.bound->belStrength = STRENGTH_NONE;
        data.bound = nullptr;
        update_bel(bel);
    }
    bool checkBelAvail(BelId bel) const override { return bel_data(bel).bound == nullptr; }
    CellInfo *getBoundBelCell(BelId bel) const override { return bel_data(bel).bound; }
    CellInfo *getConflictingBelCell(BelId bel) const override { return bel_data(bel).bound; }

    void update_bel(BelId bel);
    BelId bel_by_block_idx(int x, int y, IdString type, int block_index) const;

    // -------------------------------------------------

    WireId getWireByName(IdStringList name) const override;
    IdStringList getWireName(WireId wire) const override;
    DelayQuad getWireDelay(WireId wire) const override { return DelayQuad(0); }
    const std::vector<BelPin> &getWireBelPins(WireId wire) const override { return wires.at(wire).bel_pins; }
    AllWireRange getWires() const override { return AllWireRange(wires); }

    bool wires_connected(WireId src, WireId dst) const;
    // Only allow src, and not any other wire, to drive dst
    void reserve_route(WireId src, WireId dst);

    // -------------------------------------------------

    PipId getPipByName(IdStringList name) const override;
    AllPipRange getPips() const override { return AllPipRange(wires); }
    Loc getPipLocation(PipId pip) const override { return Loc(CycloneV::rn2x(pip.dst), CycloneV::rn2y(pip.dst), 0); }
    IdStringList getPipName(PipId pip) const override;
    WireId getPipSrcWire(PipId pip) const override { return WireId(pip.src); };
    WireId getPipDstWire(PipId pip) const override { return WireId(pip.dst); };
    UpDownhillPipRange getPipsDownhill(WireId wire) const override
    {
        return UpDownhillPipRange(wires.at(wire).wires_downhill, wire, false);
    }
    UpDownhillPipRange getPipsUphill(WireId wire) const override
    {
        return UpDownhillPipRange(wires.at(wire).wires_uphill, wire, true);
    }

    bool is_pip_blocked(PipId pip) const
    {
        WireId dst(pip.dst);
        const auto &dst_data = wires.at(dst);
        if ((dst_data.flags & WireInfo::RESERVED_ROUTE) != 0) {
            if (WireId(pip.src) != dst_data.wires_uphill.at(dst_data.flags & 0xFF))
                return true;
        }
        return false;
    }

    bool checkPipAvail(PipId pip) const override
    {
        // Check reserved routes
        if (is_pip_blocked(pip))
            return false;
        return BaseArch::checkPipAvail(pip);
    }

    bool checkPipAvailForNet(PipId pip, const NetInfo *net) const override
    {
        if (is_pip_blocked(pip))
            return false;
        return BaseArch::checkPipAvailForNet(pip, net);
    }

    // -------------------------------------------------

    delay_t estimateDelay(WireId src, WireId dst) const override;
    delay_t predictDelay(BelId src_bel, IdString src_pin, BelId dst_bel, IdString dst_pin) const override;
    delay_t getDelayEpsilon() const override { return 10; };
    delay_t getRipupDelayPenalty() const override { return 100; };
    float getDelayNS(delay_t v) const override { return float(v) / 1000.0f; };
    delay_t getDelayFromNS(float ns) const override { return delay_t(ns * 1000.0f); };
    uint32_t getDelayChecksum(delay_t v) const override { return v; };

    BoundingBox getRouteBoundingBox(WireId src, WireId dst) const override;

    TimingPortClass getPortTimingClass(const CellInfo *cell, IdString port,
                                       int &clockInfoCount) const override;                                // delay.cc
    TimingClockingInfo getPortClockingInfo(const CellInfo *cell, IdString port, int index) const override; // delay.cc
    bool getCellDelay(const CellInfo *cell, IdString fromPort, IdString toPort,
                      DelayQuad &delay) const override;                                                      // delay.cc
    DelayQuad getPipDelay(PipId pip) const override;                                                         // delay.cc
    bool getArcDelayOverride(const NetInfo *net_info, const PortRef &sink, DelayQuad &delay) const override; // delay.cc

    // -------------------------------------------------

    const std::vector<IdString> &getBelPinsForCellPin(const CellInfo *cell_info, IdString pin) const override
    {
        return cell_info->pin_data.at(pin).bel_pins;
    }

    bool isValidBelForCellType(IdString cell_type, BelId bel) const override;
    BelBucketId getBelBucketForCellType(IdString cell_type) const override;
    BelBucketId getBelBucketForBel(BelId bel) const override;

    // -------------------------------------------------
    // Expanding bounding box seems to make thing worse for CycloneV
    // as it slows down the resolution of TD congestion, disabling it
    void expandBoundingBox(BoundingBox &bb) const override {};
    // -------------------------------------------------

    void assignArchInfo() override;
    bool pack() override;
    bool place() override;
    bool route() override;

    // -------------------------------------------------
    // Functions for device setup

    BelId add_bel(int x, int y, IdString name, IdString type);
    WireId add_wire(int x, int y, IdString name, uint64_t flags = 0);
    PipId add_pip(WireId src, WireId dst);

    void add_bel_pin(BelId bel, IdString pin, PortType dir, WireId wire);

    CycloneV::rnode_t find_rnode(CycloneV::block_type_t bt, int x, int y, CycloneV::port_type_t port, int bi = -1,
                                 int pi = -1) const;
    WireId get_port(CycloneV::block_type_t bt, int x, int y, int bi, CycloneV::port_type_t port, int pi = -1) const;
    bool has_port(CycloneV::block_type_t bt, int x, int y, int bi, CycloneV::port_type_t port, int pi = -1) const;

    void create_lab(int x, int y, bool is_mlab);       // lab.cc
    void create_m10k(int x, int y);                    // m10k.cc
    void create_gpio(int x, int y);                    // io.cc
    void create_clkbuf(int x, int y);                  // globals.cc
    void create_control(int x, int y);                 // globals.cc
    void create_hps_mpu_general_purpose(int x, int y); // globals.cc

    // -------------------------------------------------

    bool is_comb_cell(IdString cell_type) const;        // lab.cc
    bool is_alm_legal(uint32_t lab, uint8_t alm) const; // lab.cc
    bool is_lab_ctrlset_legal(uint32_t lab) const;      // lab.cc
    bool check_lab_input_count(uint32_t lab) const;     // lab.cc
    bool check_mlab_groups(uint32_t lab) const;         // lab.cc

    void assign_comb_info(CellInfo *cell) const; // lab.cc
    void assign_ff_info(CellInfo *cell) const;   // lab.cc

    void lab_pre_route();                                   // lab.cc
    void assign_control_sets(uint32_t lab);                 // lab.cc
    void reassign_alm_inputs(uint32_t lab, uint8_t alm);    // lab.cc
    void update_alm_input_count(uint32_t lab, uint8_t alm); // lab.cc

    uint64_t compute_lut_mask(uint32_t lab, uint8_t alm); // lab.cc

    // Keeping track of unique MLAB write ports to assign them indices
    dict<IdString, IdString> get_mlab_key(const CellInfo *cell, bool include_raddr = false) const; // lab.cc
    mutable idict<dict<IdString, IdString>> mlab_groups;

    // -------------------------------------------------

    bool is_io_cell(IdString cell_type) const;                   // io.cc
    BelId get_io_pin_bel(const CycloneV::pin_info_t *pin) const; // io.cc

    // -------------------------------------------------

    bool is_clkbuf_cell(IdString cell_type) const; // globals.cc
    void route_globals();                          // globals.cc

    // -------------------------------------------------

    static const std::string defaultPlacer;
    static const std::vector<std::string> availablePlacers;
    static const std::string defaultRouter;
    static const std::vector<std::string> availableRouters;

    dict<WireId, WireInfo> wires;

    // List of LABs
    std::vector<LABInfo> labs;

    // WIP to link without failure
    std::vector<BelPin> empty_belpin_list;

    // Conversion between numbers and rnode types and IdString, for fast wire name implementation
    std::vector<IdString> int2id;
    dict<IdString, int> id2int;

    std::vector<IdString> rn_t2id;
    dict<IdString, CycloneV::rnode_type_t> id2rn_t;

    // This structure is only used for nextpnr-created wires
    dict<IdStringList, WireId> npnr_wirebyname;

    std::vector<std::vector<BelInfo>> bels_by_tile;
    std::vector<BelId> all_bels;

    size_t pos2idx(int x, int y) const
    {
        NPNR_ASSERT(x >= 0 && x < int(cyclonev->get_tile_sx()));
        NPNR_ASSERT(y >= 0 && y < int(cyclonev->get_tile_sy()));
        return y * cyclonev->get_tile_sx() + x;
    }

    size_t pos2idx(CycloneV::pos_t pos) const { return pos2idx(CycloneV::pos2x(pos), CycloneV::pos2y(pos)); }

    BelInfo &bel_data(BelId bel) { return bels_by_tile.at(pos2idx(bel.pos)).at(bel.z); }
    const BelInfo &bel_data(BelId bel) const { return bels_by_tile.at(pos2idx(bel.pos)).at(bel.z); }

    // -------------------------------------------------

    void assign_default_pinmap(CellInfo *cell);
    static const dict<IdString, IdString> comb_pinmap;

    // -------------------------------------------------

    typedef dict<IdString, CellPinStyle> CellPinsData;                          // pins.cc
    static const dict<IdString, CellPinsData> cell_pins_db;                     // pins.cc
    CellPinStyle get_cell_pin_style(const CellInfo *cell, IdString port) const; // pins.cc

    // -------------------------------------------------

    // List of IO constraints, used by QSF parser
    dict<IdString, dict<IdString, Property>> io_attr;
    void read_qsf(std::istream &in); // qsf.cc

    // -------------------------------------------------

    void build_bitstream(); // bitstream.cc
};

NEXTPNR_NAMESPACE_END

#endif