/** FPGA card.
 *
 * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
 * @copyright 2017, Institute for Automation of Complex Power Systems, EONERC
 * @license GNU General Public License (version 3)
 *
 * VILLASnode
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************************/

#include <unistd.h>

#include "config.h"
#include "log.h"
#include "log_config.h"
#include "list.h"
#include "utils.h"

#include "kernel/pci.h"
#include "kernel/vfio.h"

#include "fpga/ip.h"
#include "fpga/card.h"

int fpga_card_init(struct fpga_card *c, struct pci *pci, struct vfio_container *vc)
{
	assert(c->state = STATE_DESTROYED);

	c->vfio_container = vc;
	c->pci = pci;

	list_init(&c->ips);

	/* Default values */
	c->filter.id.vendor = FPGA_PCI_VID_XILINX;
	c->filter.id.device = FPGA_PCI_PID_VFPGA;

	c->affinity = 0;
	c->do_reset = 0;

	c->state = STATE_INITIALIZED;

	return 0;
}

int fpga_card_parse(struct fpga_card *c, config_setting_t *cfg)
{
	int ret;
	const char *slot, *id, *err;
	config_setting_t *cfg_ips, *cfg_slot, *cfg_id;

	c->name = config_setting_name(cfg);

	config_setting_lookup_int(cfg, "affinity", &c->affinity);
	config_setting_lookup_bool(cfg, "do_reset", &c->do_reset);

	cfg_slot = config_setting_get_member(cfg, "slot");
	if (cfg_slot) {
		slot = config_setting_get_string(cfg_slot);
		if (slot) {
			ret = pci_device_parse_slot(&c->filter, slot, &err);
			if (ret)
				cerror(cfg_slot, "Failed to parse PCI slot: %s", err);
		}
		else
			cerror(cfg_slot, "PCI slot must be a string");
	}

	cfg_id = config_setting_get_member(cfg, "id");
	if (cfg_id) {
		id = config_setting_get_string(cfg_id);
		if (id) {
			ret = pci_device_parse_id(&c->filter, (char*) id, &err);
			if (ret)
				cerror(cfg_id, "Failed to parse PCI id: %s", err);
		}
		else
			cerror(cfg_slot, "PCI ID must be a string");
	}

	cfg_ips = config_setting_get_member(cfg, "ips");
	if (!cfg_ips)
		cerror(cfg, "FPGA configuration is missing ips section");

	for (int i = 0; i < config_setting_length(cfg_ips); i++) {
		config_setting_t *cfg_ip = config_setting_get_elem(cfg_ips, i);

		const char *vlnv;

		struct fpga_ip_type *vt;
		struct fpga_ip ip = {
			.card = c,
			.state = STATE_DESTROYED
		};

		if (!config_setting_lookup_string(cfg, "vlnv", &vlnv))
			cerror(cfg, "FPGA IP core %s is missing the VLNV identifier", c->name);

		vt = fpga_ip_type_lookup(vlnv);
		if (!vt)
			cerror(cfg, "FPGA IP core VLNV identifier '%s' is invalid", vlnv);

		ret = fpga_ip_init(&ip, vt);
		if (ret)
			error("Failed to initalize FPGA IP core");

		ret = fpga_ip_parse(&ip, cfg_ip);
		if (ret)
			cerror(cfg_ip, "Failed to parse FPGA IP core");

		list_push(&c->ips, memdup(&ip, sizeof(ip)));
	}

	c->cfg = cfg;
	c->state = STATE_PARSED;

	return 0;
}

int fpga_card_parse_list(struct list *cards, config_setting_t *cfg)
{
	int ret;

	if (!config_setting_is_group(cfg))
		cerror(cfg, "FPGA configuration section must be a group");

	for (int i = 0; i < config_setting_length(cfg); i++) {
		config_setting_t *cfg_fpga = config_setting_get_elem(cfg, i);

		struct fpga_card c;

		ret = fpga_card_parse(&c, cfg_fpga);
		if (ret)
			cerror(cfg_fpga, "Failed to parse FPGA card configuration");

		list_push(cards, memdup(&c, sizeof(c)));
	}

	return 0;
}

int fpga_card_start(struct fpga_card *c)
{
	int ret;

	struct pci_device *pdev;

	assert(c->state == STATE_CHECKED);

	/* Search for FPGA card */
	pdev = pci_lookup_device(c->pci, &c->filter);
	if (!pdev)
		error("Failed to find PCI device");

	/* Attach PCIe card to VFIO container */
	ret = vfio_pci_attach(&c->vfio_device, c->vfio_container, pdev);
	if (ret)
		error("Failed to attach VFIO device");

	/* Map PCIe BAR */
	c->map = vfio_map_region(&c->vfio_device, VFIO_PCI_BAR0_REGION_INDEX);
	if (c->map == MAP_FAILED)
		serror("Failed to mmap() BAR0");

	/* Enable memory access and PCI bus mastering for DMA */
	ret = vfio_pci_enable(&c->vfio_device);
	if (ret)
		serror("Failed to enable PCI device");

	/* Reset system? */
	if (c->do_reset) {
		/* Reset / detect PCI device */
		ret = vfio_pci_reset(&c->vfio_device);
		if (ret)
			serror("Failed to reset PCI device");

		ret = fpga_card_reset(c);
		if (ret)
			error("Failed to reset FGPA card");
	}

	/* Initialize IP cores */
	for (size_t j = 0; j < list_length(&c->ips); j++) {
		struct fpga_ip *i = list_at(&c->ips, j);

		ret = fpga_ip_start(i);
		if (ret)
			error("Failed to initalize FPGA IP core: %s (%u)", i->name, ret);
	}

	c->state = STATE_STARTED;

	return 0;
}

int fpga_card_stop(struct fpga_card *c)
{
	int ret;

	assert(c->state == STATE_STOPPED);

	for (size_t j = 0; j < list_length(&c->ips); j++) {
		struct fpga_ip *i = list_at(&c->ips, j);

		ret = fpga_ip_stop(i);
		if (ret)
			error("Failed to stop FPGA IP core: %s (%u)", i->name, ret);
	}

	c->state = STATE_STOPPED;

	return 0;
}

void fpga_card_dump(struct fpga_card *c)
{
	info("VILLASfpga card:");
	{ INDENT
		info("Slot: %04x:%02x:%02x.%d", c->vfio_device.pci_device->slot.domain, c->vfio_device.pci_device->slot.bus, c->vfio_device.pci_device->slot.device, c->vfio_device.pci_device->slot.function);
		info("Vendor ID: %04x", c->vfio_device.pci_device->id.vendor);
		info("Device ID: %04x", c->vfio_device.pci_device->id.device);
		info("Class  ID: %04x", c->vfio_device.pci_device->id.class);

		info("BAR0 mapped at %p", c->map);

		info("IP blocks:");
		for (size_t j = 0; j < list_length(&c->ips); j++) { INDENT
			struct fpga_ip *i = list_at(&c->ips, j);

			fpga_ip_dump(i);
		}
	}

	vfio_dump(c->vfio_device.group->container);
}

int fpga_card_check(struct fpga_card *c)
{
	/* Check FPGA configuration */
	c->reset = fpga_vlnv_lookup(&c->ips, &(struct fpga_vlnv) { "xilinx.com", "ip", "axi_gpio", NULL });
	if (!c->reset)
		error("FPGA is missing a reset controller");

	c->intc = fpga_vlnv_lookup(&c->ips, &(struct fpga_vlnv) { "acs.eonerc.rwth-aachen.de", "user", "axi_pcie_intc", NULL });
	if (!c->intc)
		error("FPGA is missing a interrupt controller");

	c->sw = fpga_vlnv_lookup(&c->ips, &(struct fpga_vlnv) { "xilinx.com", "ip", "axis_interconnect", NULL });
	if (!c->sw)
		warn("FPGA is missing an AXI4-Stream switch");

	return 0;
}

int fpga_card_destroy(struct fpga_card *c)
{
	list_destroy(&c->ips, (dtor_cb_t) fpga_ip_destroy, true);

	return 0;
}

int fpga_card_reset(struct fpga_card *c)
{
	int ret;
	char state[4096];

	/* Save current state of PCI configuration space */
	ret = pread(c->vfio_device.fd, state, sizeof(state), (off_t) VFIO_PCI_CONFIG_REGION_INDEX << 40);
	if (ret != sizeof(state))
		return -1;

	uint32_t *rst_reg = (uint32_t *) (c->map + c->reset->baseaddr);

	debug(3, "FPGA: reset");
	rst_reg[0] = 1;

	usleep(100000);

	/* Restore previous state of PCI configuration space */
	ret = pwrite(c->vfio_device.fd, state, sizeof(state), (off_t) VFIO_PCI_CONFIG_REGION_INDEX << 40);
	if (ret != sizeof(state))
		return -1;

	/* After reset the value should be zero again */
	if (rst_reg[0])
		return -2;

	c->state = STATE_INITIALIZED;

	return 0;
}