nextpnr/fpga_interchange/arch_pack_io.cc
Keith Rothman f9bd692f75 Change how package pin IO sites are selected.
The first site type that matches is now selected, under the premise that
the early site types are more general.

Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
2021-02-17 12:03:16 -08:00

256 lines
10 KiB
C++

/*
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2021 Symbiflow Authors
*
*
* 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.
*
*/
#include "log.h"
#include "nextpnr.h"
NEXTPNR_NAMESPACE_BEGIN
void Arch::place_iobufs(WireId pad_wire, NetInfo *net, const std::unordered_set<CellInfo *> &tightly_attached_bels,
std::unordered_set<CellInfo *> *placed_cells)
{
for (BelPin bel_pin : getWireBelPins(pad_wire)) {
BelId bel = bel_pin.bel;
for (CellInfo *cell : tightly_attached_bels) {
if (isValidBelForCellType(cell->type, bel)) {
NPNR_ASSERT(cell->bel == BelId());
NPNR_ASSERT(placed_cells->count(cell) == 0);
bindBel(bel, cell, STRENGTH_FIXED);
placed_cells->emplace(cell);
IdString cell_port;
for (auto pin_pair : cell->cell_bel_pins) {
for (IdString a_bel_pin : pin_pair.second) {
if (a_bel_pin == bel_pin.pin) {
NPNR_ASSERT(cell_port == IdString());
cell_port = pin_pair.first;
}
}
}
NPNR_ASSERT(cell_port != IdString());
const PortInfo &port = cell->ports.at(cell_port);
NPNR_ASSERT(port.net == net);
}
}
}
}
void Arch::pack_ports()
{
std::unordered_map<IdString, const TileInstInfoPOD *> tile_type_prototypes;
for (size_t i = 0; i < chip_info->tiles.size(); ++i) {
const auto &tile = chip_info->tiles[i];
const auto &tile_type = chip_info->tile_types[tile.type];
IdString tile_type_name(tile_type.name);
tile_type_prototypes.emplace(tile_type_name, &tile);
}
// set(site_types) for package pins
std::unordered_set<IdString> package_sites;
// Package pin -> (Site type -> BelId)
std::unordered_map<IdString, std::vector<std::pair<IdString, BelId>>> package_pin_bels;
for (const PackagePinPOD &package_pin : chip_info->packages[package_index].pins) {
IdString pin(package_pin.package_pin);
IdString bel(package_pin.bel);
IdString site(package_pin.site);
package_sites.emplace(site);
for (size_t i = 0; i < chip_info->tiles.size(); ++i) {
const auto &tile = chip_info->tiles[i];
std::unordered_set<uint32_t> package_pin_sites;
for (size_t j = 0; j < tile.sites.size(); ++j) {
auto &site_data = chip_info->sites[tile.sites[j]];
if (site == id(site_data.site_name.get())) {
package_pin_sites.emplace(j);
}
}
const auto &tile_type = chip_info->tile_types[tile.type];
for (size_t j = 0; j < tile_type.bel_data.size(); ++j) {
const BelInfoPOD &bel_data = tile_type.bel_data[j];
if (bel == IdString(bel_data.name) && package_pin_sites.count(bel_data.site)) {
auto &site_data = chip_info->sites[tile.sites[bel_data.site]];
IdString site_type(site_data.site_type);
BelId bel;
bel.tile = i;
bel.index = j;
package_pin_bels[pin].push_back(std::make_pair(site_type, bel));
}
}
}
}
// Determine for each package site type, which site types are possible.
std::unordered_set<IdString> package_pin_site_types;
std::unordered_map<IdString, std::unordered_set<IdString>> possible_package_site_types;
for (const TileInstInfoPOD &tile : chip_info->tiles) {
for (size_t site_index : tile.sites) {
const SiteInstInfoPOD &site = chip_info->sites[site_index];
IdString site_name = getCtx()->id(site.site_name.get());
if (package_sites.count(site_name) == 1) {
possible_package_site_types[site_name].emplace(IdString(site.site_type));
package_pin_site_types.emplace(IdString(site.site_type));
}
}
}
// IO sites are usually pretty weird, so see if we can define some
// constraints between the port cell create by nextpnr and cells that are
// immediately attached to that port cell.
for (auto port_pair : port_cells) {
IdString port_name = port_pair.first;
CellInfo *port_cell = port_pair.second;
std::unordered_set<CellInfo *> tightly_attached_bels;
for (auto port_pair : port_cell->ports) {
const PortInfo &port_info = port_pair.second;
const NetInfo *net = port_info.net;
if (net->driver.cell) {
tightly_attached_bels.emplace(net->driver.cell);
}
for (const PortRef &port_ref : net->users) {
if (port_ref.cell) {
tightly_attached_bels.emplace(port_ref.cell);
}
}
}
if (getCtx()->verbose) {
log_info("Tightly attached BELs for port %s\n", port_name.c_str(getCtx()));
for (CellInfo *cell : tightly_attached_bels) {
log_info(" - %s : %s\n", cell->name.c_str(getCtx()), cell->type.c_str(getCtx()));
}
}
NPNR_ASSERT(tightly_attached_bels.erase(port_cell) == 1);
std::unordered_set<IdString> cell_types_in_io_group;
for (CellInfo *cell : tightly_attached_bels) {
NPNR_ASSERT(port_cells.find(cell->name) == port_cells.end());
cell_types_in_io_group.emplace(cell->type);
}
// Get possible placement locations for tightly coupled BELs with
// port.
std::unordered_set<IdString> possible_site_types;
for (const TileTypeInfoPOD &tile_type : chip_info->tile_types) {
IdString tile_type_name(tile_type.name);
for (const BelInfoPOD &bel_info : tile_type.bel_data) {
if (bel_info.category != BEL_CATEGORY_LOGIC) {
break;
}
for (IdString cell_type : cell_types_in_io_group) {
size_t cell_type_index = get_cell_type_index(cell_type);
if (bel_info.category == BEL_CATEGORY_LOGIC && bel_info.pin_map[cell_type_index] != -1) {
auto *tile = tile_type_prototypes.at(tile_type_name);
const SiteInstInfoPOD &site = chip_info->sites[tile->sites[bel_info.site]];
IdString site_type(site.site_type);
if (package_pin_site_types.count(site_type)) {
possible_site_types.emplace(site_type);
}
}
}
}
}
if (possible_site_types.empty()) {
log_error("Port '%s' has no possible site types!\n", port_name.c_str(getCtx()));
}
if (getCtx()->verbose) {
log_info("Possible site types for port %s\n", port_name.c_str(getCtx()));
for (IdString site_type : possible_site_types) {
log_info(" - %s\n", site_type.c_str(getCtx()));
}
}
auto iter = port_cell->attrs.find(id("PACKAGE_PIN"));
if (iter == port_cell->attrs.end()) {
// FIXME: Relax this constraint
log_error("Port '%s' is missing PACKAGE_PIN property\n", port_cell->name.c_str(getCtx()));
}
// std::unordered_map<IdString, std::unordered_map<IdString, BelId>> package_pin_bels;
IdString package_pin_id = id(iter->second.as_string());
auto pin_iter = package_pin_bels.find(package_pin_id);
if (pin_iter == package_pin_bels.end()) {
log_error("Package pin '%s' not found in part %s\n", package_pin_id.c_str(getCtx()), get_part().c_str());
}
NPNR_ASSERT(pin_iter != package_pin_bels.end());
// Select the first BEL from package_bel_pins that is a legal site
// type.
//
// This is likely the most generic (versus specialized) site type.
BelId package_bel;
for (auto site_type_and_bel : pin_iter->second) {
IdString legal_site_type = site_type_and_bel.first;
BelId bel = site_type_and_bel.second;
if (possible_site_types.count(legal_site_type)) {
// FIXME: Need to handle case where a port can be in multiple
// modes, but only one of the modes works.
package_bel = bel;
break;
}
}
if (package_bel == BelId()) {
log_info("Failed to find BEL for package pin '%s' in any possible site types:\n",
package_pin_id.c_str(getCtx()));
for (IdString site_type : possible_site_types) {
log_info(" - %s\n", site_type.c_str(getCtx()));
}
log_error("Failed to find BEL for package pin '%s'\n", package_pin_id.c_str(getCtx()));
}
if (getCtx()->verbose) {
log_info("Binding port %s to BEL %s\n", port_name.c_str(getCtx()), getCtx()->nameOfBel(package_bel));
}
std::unordered_set<CellInfo *> placed_cells;
bindBel(package_bel, port_cell, STRENGTH_FIXED);
placed_cells.emplace(port_cell);
IdStringRange package_bel_pins = getBelPins(package_bel);
// NPNR_ASSERT(std::distance(package_bel_pins.begin(), package_bel_pins.end()) == 1);
IdStringIterator b = package_bel_pins.begin();
NPNR_ASSERT(b != package_bel_pins.end());
++b;
NPNR_ASSERT(b == package_bel_pins.end());
IdString pad_pin = *package_bel_pins.begin();
WireId pad_wire = getBelPinWire(package_bel, pad_pin);
place_iobufs(pad_wire, ports[port_pair.first].net, tightly_attached_bels, &placed_cells);
for (CellInfo *cell : placed_cells) {
NPNR_ASSERT(cell->bel != BelId());
NPNR_ASSERT(isBelLocationValid(cell->bel));
}
}
}
NEXTPNR_NAMESPACE_END