/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2022 Scott Long
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "opt_thunderbolt.h"

/* PCIe interface for Thunderbolt Native Host Interface */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/malloc.h>
#include <sys/sysctl.h>
#include <sys/lock.h>
#include <sys/param.h>
#include <sys/endian.h>
#include <sys/taskqueue.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/stdarg.h>
#include <sys/rman.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pci_private.h>

#include <dev/thunderbolt/tb_reg.h>
#include <dev/thunderbolt/nhi_reg.h>
#include <dev/thunderbolt/nhi_var.h>
#include <dev/thunderbolt/tbcfg_reg.h>
#include <dev/thunderbolt/router_var.h>
#include <dev/thunderbolt/tb_debug.h>
#include "tb_if.h"

static int	nhi_pci_probe(device_t);
static int	nhi_pci_attach(device_t);
static int	nhi_pci_detach(device_t);
static int	nhi_pci_suspend(device_t);
static int	nhi_pci_resume(device_t);
static void	nhi_pci_free(struct nhi_softc *);
static int	nhi_pci_allocate_interrupts(struct nhi_softc *);
static void	nhi_pci_free_interrupts(struct nhi_softc *);
static int	nhi_pci_icl_poweron(struct nhi_softc *);

static device_method_t nhi_methods[] = {
	DEVMETHOD(device_probe, 	nhi_pci_probe),
	DEVMETHOD(device_attach,	nhi_pci_attach),
	DEVMETHOD(device_detach,	nhi_pci_detach),
	DEVMETHOD(device_suspend,	nhi_pci_suspend),
	DEVMETHOD(device_resume,	nhi_pci_resume),

	DEVMETHOD(tb_find_ufp,		tb_generic_find_ufp),
	DEVMETHOD(tb_get_debug,		tb_generic_get_debug),

	DEVMETHOD_END
};

static driver_t nhi_pci_driver = {
	"nhi",
	nhi_methods,
	sizeof(struct nhi_softc)
};

struct nhi_ident {
	uint16_t	vendor;
	uint16_t	device;
	uint16_t	subvendor;
	uint16_t	subdevice;
	uint32_t	flags;
	const char	*desc;
} nhi_identifiers[] = {
	{ VENDOR_INTEL, DEVICE_AR_2C_NHI, 0xffff, 0xffff, NHI_TYPE_AR,
	    "Thunderbolt 3 NHI (Alpine Ridge 2C)" },
	{ VENDOR_INTEL, DEVICE_AR_DP_B_NHI, 0xffff, 0xffff, NHI_TYPE_AR,
	    "Thunderbolt 3 NHI (Alpine Ridge 4C Rev B)" },
	{ VENDOR_INTEL, DEVICE_AR_DP_C_NHI, 0xffff, 0xffff, NHI_TYPE_AR,
	    "Thunderbolt 3 NHI (Alpine Ridge 4C Rev C)" },
	{ VENDOR_INTEL, DEVICE_AR_LP_NHI, 0xffff, 0xffff, NHI_TYPE_AR,
	    "Thunderbolt 3 NHI (Alpine Ridge LP 2C)" },
	{ VENDOR_INTEL, DEVICE_ICL_NHI_0, 0xffff, 0xffff, NHI_TYPE_ICL,
	    "Thunderbolt 3 NHI Port 0 (IceLake)" },
	{ VENDOR_INTEL, DEVICE_ICL_NHI_1, 0xffff, 0xffff, NHI_TYPE_ICL,
	    "Thunderbolt 3 NHI Port 1 (IceLake)" },
	{ VENDOR_AMD, DEVICE_PINK_SARDINE_0, 0xffff, 0xffff, NHI_TYPE_USB4,
	    "USB4 NHI Port 0 (Pink Sardine)" },
	{ VENDOR_AMD, DEVICE_PINK_SARDINE_1, 0xffff, 0xffff, NHI_TYPE_USB4,
	    "USB4 NHI Port 1 (Pink Sardine)" },
	{ 0, 0, 0, 0, 0, NULL }
};

DRIVER_MODULE_ORDERED(nhi, pci, nhi_pci_driver, NULL, NULL,
    SI_ORDER_ANY);
MODULE_PNP_INFO("U16:vendor;U16:device;V16:subvendor;V16:subdevice;U32:#;D:#",
    pci, nhi, nhi_identifiers, nitems(nhi_identifiers) - 1);

static struct nhi_ident *
nhi_find_ident(device_t dev)
{
	struct nhi_ident *n;

	for (n = nhi_identifiers; n->vendor != 0; n++) {
		if (n->vendor != pci_get_vendor(dev))
			continue;
		if (n->device != pci_get_device(dev))
			continue;
		if ((n->subvendor != 0xffff) &&
		    (n->subvendor != pci_get_subvendor(dev)))
			continue;
		if ((n->subdevice != 0xffff) &&
		    (n->subdevice != pci_get_subdevice(dev)))
			continue;
		return (n);
	}

	return (NULL);
}

static int
nhi_pci_probe(device_t dev)
{
	struct nhi_ident *n;

	if (resource_disabled("tb", 0))
		return (ENXIO);
	if ((n = nhi_find_ident(dev)) != NULL) {
		device_set_desc(dev, n->desc);
		return (BUS_PROBE_DEFAULT);
	}
	return (ENXIO);
}

static int
nhi_pci_attach(device_t dev)
{
	devclass_t dc;
	bus_dma_template_t t;
	struct nhi_softc *sc;
	struct nhi_ident *n;
	int error = 0;

	sc = device_get_softc(dev);
	bzero(sc, sizeof(*sc));
	sc->dev = dev;
	n = nhi_find_ident(dev);
	sc->hwflags = n->flags;
	nhi_get_tunables(sc);

	tb_debug(sc, DBG_INIT|DBG_FULL, "busmaster status was %s\n",
	    (pci_read_config(dev, PCIR_COMMAND, 2) & PCIM_CMD_BUSMASTEREN)
	    ? "enabled" : "disabled");
	pci_enable_busmaster(dev);

	sc->ufp = NULL;
	if ((TB_FIND_UFP(dev, &sc->ufp) != 0) || (sc->ufp == NULL)) {
		dc = devclass_find("tbolt");
		if (dc != NULL)
			sc->ufp = devclass_get_device(dc, device_get_unit(dev));
	}
	if (sc->ufp == NULL)
		tb_printf(sc, "Cannot find Upstream Facing Port\n");
	else
		tb_printf(sc, "Upstream Facing Port is %s\n",
		    device_get_nameunit(sc->ufp));

	if (NHI_IS_ICL(sc)) {
		if ((error = nhi_pci_icl_poweron(sc)) != 0)
			return (error);
	}


	/* Allocate BAR0 DMA registers */
	sc->regs_rid = PCIR_BAR(0);
	if ((sc->regs_resource = bus_alloc_resource_any(dev,
	    SYS_RES_MEMORY, &sc->regs_rid, RF_ACTIVE)) == NULL) {
		tb_printf(sc, "Cannot allocate PCI registers\n");
		return (ENXIO);
	}
	sc->regs_btag = rman_get_bustag(sc->regs_resource);
	sc->regs_bhandle = rman_get_bushandle(sc->regs_resource);

	/* Allocate parent DMA tag */
	bus_dma_template_init(&t, bus_get_dma_tag(dev));
	if (bus_dma_template_tag(&t, &sc->parent_dmat) != 0) {
		tb_printf(sc, "Cannot allocate parent DMA tag\n");
		nhi_pci_free(sc);
		return (ENOMEM);
	}

	error = nhi_pci_allocate_interrupts(sc);
	if (error == 0)
		error = nhi_attach(sc);
	if (error != 0)
		nhi_pci_detach(sc->dev);
	return (error);
}

static int
nhi_pci_detach(device_t dev)
{
	struct nhi_softc *sc;

	sc = device_get_softc(dev);

	nhi_detach(sc);
	nhi_pci_free(sc);

	return (0);
}

static int
nhi_pci_suspend(device_t dev)
{

	return (0);
}

static int
nhi_pci_resume(device_t dev)
{

	return (0);
}

static void
nhi_pci_free(struct nhi_softc *sc)
{

	nhi_pci_free_interrupts(sc);

	if (sc->parent_dmat != NULL) {
		bus_dma_tag_destroy(sc->parent_dmat);
		sc->parent_dmat = NULL;
	}

	if (sc->regs_resource != NULL) {
		bus_release_resource(sc->dev, SYS_RES_MEMORY,
		    sc->regs_rid, sc->regs_resource);
		sc->regs_resource = NULL;
	}

	return;
}

static int
nhi_pci_allocate_interrupts(struct nhi_softc *sc)
{
	int msgs, error = 0;

	/* Map the Pending Bit Array and Vector Table BARs for MSI-X */
	sc->irq_pba_rid = pci_msix_pba_bar(sc->dev);
	sc->irq_table_rid = pci_msix_table_bar(sc->dev);

	if (sc->irq_pba_rid != -1)
		sc->irq_pba = bus_alloc_resource_any(sc->dev, SYS_RES_MEMORY,
		    &sc->irq_pba_rid, RF_ACTIVE);
	if (sc->irq_table_rid != -1)
		sc->irq_table = bus_alloc_resource_any(sc->dev, SYS_RES_MEMORY,
		    &sc->irq_table_rid, RF_ACTIVE);

	msgs = pci_msix_count(sc->dev);
	tb_debug(sc, DBG_INIT|DBG_INTR|DBG_FULL,
	    "Counted %d MSI-X messages\n", msgs);
	msgs = min(msgs, NHI_MSIX_MAX);
	msgs = max(msgs, 1);
	if (msgs != 0) {
		tb_debug(sc, DBG_INIT|DBG_INTR, "Attempting to allocate %d "
		    "MSI-X interrupts\n", msgs);
		error = pci_alloc_msix(sc->dev, &msgs);
		tb_debug(sc, DBG_INIT|DBG_INTR|DBG_FULL,
		    "pci_alloc_msix return msgs= %d, error= %d\n", msgs, error);
	}

	if ((error != 0) || (msgs <= 0)) {
		tb_printf(sc, "Failed to allocate any interrupts\n");
		msgs = 0;
	}

	sc->msix_count = msgs;
	return (error);
}

static void
nhi_pci_free_interrupts(struct nhi_softc *sc)
{
	int i;

	for (i = 0; i < sc->msix_count; i++) {
		bus_teardown_intr(sc->dev, sc->irqs[i], sc->intrhand[i]);
		bus_release_resource(sc->dev, SYS_RES_IRQ, sc->irq_rid[i],
		    sc->irqs[i]);
	}

	pci_release_msi(sc->dev);

	if (sc->irq_table != NULL) {
		bus_release_resource(sc->dev, SYS_RES_MEMORY,
		    sc->irq_table_rid, sc->irq_table);
		sc->irq_table = NULL;
	}

	if (sc->irq_pba != NULL) {
		bus_release_resource(sc->dev, SYS_RES_MEMORY,
		    sc->irq_pba_rid, sc->irq_pba);
		sc->irq_pba = NULL;
	}

	if (sc->intr_trackers != NULL)
		free(sc->intr_trackers, M_NHI);
	return;
}

int
nhi_pci_configure_interrupts(struct nhi_softc *sc)
{
	struct nhi_intr_tracker *trkr;
	int rid, i, error;

	nhi_pci_disable_interrupts(sc);

	sc->intr_trackers = malloc(sizeof(struct nhi_intr_tracker) *
	    sc->msix_count, M_NHI, M_ZERO | M_NOWAIT);
	if (sc->intr_trackers == NULL) {
		tb_debug(sc, DBG_INIT, "Cannot allocate intr trackers\n");
		return (ENOMEM);
	}

	for (i = 0; i < sc->msix_count; i++) {
		rid = i + 1;
		trkr = &sc->intr_trackers[i];
		trkr->sc = sc;
		trkr->ring = NULL;
		trkr->vector = i;

		sc->irq_rid[i] = rid;
		sc->irqs[i] = bus_alloc_resource_any(sc->dev, SYS_RES_IRQ,
			&sc->irq_rid[i], RF_ACTIVE);
		if (sc->irqs[i] == NULL) {
			tb_debug(sc, DBG_INIT,
			    "Cannot allocate interrupt RID %d\n",
			    sc->irq_rid[i]);
			break;
		}
		error = bus_setup_intr(sc->dev, sc->irqs[i], INTR_TYPE_BIO |
		    INTR_MPSAFE, NULL, nhi_intr, trkr, &sc->intrhand[i]);
		if (error) {
			tb_debug(sc, DBG_INIT,
			    "cannot setup interrupt RID %d\n", sc->irq_rid[i]);
			break;
		}
	}

	tb_debug(sc, DBG_INIT, "Set up %d interrupts\n", sc->msix_count);

	/* Set the interrupt throttle rate to 128us */
	for (i = 0; i < 16; i ++)
		nhi_write_reg(sc, NHI_ITR0 + i * 4, 0x1f4);

	return (error);
}

#define NHI_SET_INTERRUPT(offset, mask, val)	\
do {					\
	reg = offset / 32;		\
	offset %= 32;			\
	ivr[reg] &= ~(mask << offset);	\
	ivr[reg] |= (val << offset);	\
} while (0)

void
nhi_pci_enable_interrupt(struct nhi_ring_pair *r)
{
	struct nhi_softc *sc = r->sc;
	uint32_t ivr[5];
	u_int offset, reg;

	tb_debug(sc, DBG_INIT|DBG_INTR, "Enabling interrupts for ring %d\n",
	    r->ring_num);
	/*
	 * Compute the routing between event type and MSI-X vector.
	 * 4 bits per descriptor.
	 */
	ivr[0] = nhi_read_reg(sc, NHI_IVR0);
	ivr[1] = nhi_read_reg(sc, NHI_IVR1);
	ivr[2] = nhi_read_reg(sc, NHI_IVR2);
	ivr[3] = nhi_read_reg(sc, NHI_IVR3);
	ivr[4] = nhi_read_reg(sc, NHI_IVR4);

	/* Program TX */
	offset = (r->ring_num + IVR_TX_OFFSET) * 4;
	NHI_SET_INTERRUPT(offset, 0x0f, r->ring_num);

	/* Now program RX */
	offset = (r->ring_num + IVR_RX_OFFSET) * 4;
	NHI_SET_INTERRUPT(offset, 0x0f, r->ring_num);

	/* Last, program Nearly Empty.  This one always going to vector 15 */
	offset = (r->ring_num + IVR_NE_OFFSET) * 4;
	NHI_SET_INTERRUPT(offset, 0x0f, 0x0f);

	nhi_write_reg(sc, NHI_IVR0, ivr[0]);
	nhi_write_reg(sc, NHI_IVR1, ivr[1]);
	nhi_write_reg(sc, NHI_IVR2, ivr[2]);
	nhi_write_reg(sc, NHI_IVR3, ivr[3]);
	nhi_write_reg(sc, NHI_IVR4, ivr[4]);

	tb_debug(sc, DBG_INIT|DBG_INTR|DBG_FULL,
	    "Wrote IVR 0x%08x 0x%08x 0x%08x 0x%08x 0x%08x\n",
	    ivr[0], ivr[1], ivr[2], ivr[3], ivr[4]);

	/* Now do the Interrupt Mask Register, 1 bit per descriptor */
	ivr[0] = nhi_read_reg(sc, NHI_IMR0);
	ivr[1] = nhi_read_reg(sc, NHI_IMR1);

	/* Tx */
	offset = r->ring_num + IMR_TX_OFFSET;
	NHI_SET_INTERRUPT(offset, 0x01, 1);

	/* Rx */
	offset = r->ring_num + IMR_RX_OFFSET;
	NHI_SET_INTERRUPT(offset, 0x01, 1);

	/* NE */
	offset = r->ring_num + IMR_NE_OFFSET;
	NHI_SET_INTERRUPT(offset, 0x01, 1);

	nhi_write_reg(sc, NHI_IMR0, ivr[0]);
	nhi_write_reg(sc, NHI_IMR1, ivr[1]);
	tb_debug(sc, DBG_INIT|DBG_FULL,
	    "Wrote IMR 0x%08x 0x%08x\n", ivr[0], ivr[1]);
}

void
nhi_pci_disable_interrupts(struct nhi_softc *sc)
{

	tb_debug(sc, DBG_INIT, "Disabling interrupts\n");
	nhi_write_reg(sc, NHI_IMR0, 0);
	nhi_write_reg(sc, NHI_IMR1, 0);
	nhi_write_reg(sc, NHI_IVR0, 0);
	nhi_write_reg(sc, NHI_IVR1, 0);
	nhi_write_reg(sc, NHI_IVR2, 0);
	nhi_write_reg(sc, NHI_IVR3, 0);
	nhi_write_reg(sc, NHI_IVR4, 0);

	/* Dummy reads to clear pending bits */
	nhi_read_reg(sc, NHI_ISR0);
	nhi_read_reg(sc, NHI_ISR1);
}

/*
 * Icelake controllers need to be notified of power-on
 */
static int
nhi_pci_icl_poweron(struct nhi_softc *sc)
{
	device_t dev;
	uint32_t val;
	int i, error = 0;

	dev = sc->dev;
	val = pci_read_config(dev, ICL_VSCAP_9, 4);
	tb_debug(sc, DBG_INIT, "icl_poweron val= 0x%x\n", val);
	if (val & ICL_VSCAP9_FWREADY)
		return (0);

	val = pci_read_config(dev, ICL_VSCAP_22, 4);
	val |= ICL_VSCAP22_FORCEPWR;
	tb_debug(sc, DBG_INIT|DBG_FULL, "icl_poweron writing 0x%x\n", val);
	pci_write_config(dev, ICL_VSCAP_22, val, 4);

	error = ETIMEDOUT;
	for (i = 0; i < 15; i++) {
		DELAY(1000000);
		val = pci_read_config(dev, ICL_VSCAP_9, 4);
		if (val & ICL_VSCAP9_FWREADY) {
			error = 0;
			break;
		}
	}

	return (error);
}

/*
 * Icelake and Alderlake controllers store their UUID in PCI config space
 */
int
nhi_pci_get_uuid(struct nhi_softc *sc)
{
	device_t dev;
	uint32_t val[4];

	dev = sc->dev;
	val[0] = pci_read_config(dev, ICL_VSCAP_10, 4);
	val[1] = pci_read_config(dev, ICL_VSCAP_11, 4);
	val[2] = 0xffffffff;
	val[3] = 0xffffffff;

	bcopy(val, &sc->uuid, 16);
	return (0);
}