/* $NetBSD: acpipchb.c,v 1.29 2022/08/13 16:44:11 jmcneill Exp $ */

/*-
 * Copyright (c) 2018 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jared McNeill <jmcneill@invisible.ca>.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: acpipchb.c,v 1.29 2022/08/13 16:44:11 jmcneill Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/intr.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/queue.h>
#include <sys/mutex.h>
#include <sys/kmem.h>
#include <sys/cpu.h>

#include <arm/cpufunc.h>
#include <arm/bootconfig.h>

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

#include <dev/acpi/acpivar.h>
#include <dev/acpi/acpi_pci.h>
#include <dev/acpi/acpi_mcfg.h>

#include <arm/acpi/acpi_pci_machdep.h>

#define	PCIHOST_CACHELINE_SIZE		arm_dcache_align

#define	ACPIPCHB_MAX_RANGES	64	/* XXX arbitrary limit */

struct acpipchb_bus_range {
	bus_addr_t		min;
	bus_addr_t		max;
	bus_addr_t		offset;
};

struct acpipchb_bus_space {
	struct bus_space	bs;

	struct acpipchb_bus_range range[ACPIPCHB_MAX_RANGES];
	int			nrange;

	int			(*map)(void *, bus_addr_t, bus_size_t,
				       int, bus_space_handle_t *);

	int			flags;
};

struct acpipchb_softc {
	device_t		sc_dev;

	bus_space_tag_t		sc_memt;

	ACPI_HANDLE		sc_handle;
	ACPI_INTEGER		sc_bus;

	struct acpipchb_bus_space sc_pcimem_bst;
	struct acpipchb_bus_space sc_pciio_bst;
};

static int	acpipchb_match(device_t, cfdata_t, void *);
static void	acpipchb_attach(device_t, device_t, void *);

static void	acpipchb_configure_bus(struct acpipchb_softc *, struct pcibus_attach_args *);
static void	acpipchb_setup_ranges(struct acpipchb_softc *,
				      struct pcibus_attach_args *);
static void	acpipchb_setup_quirks(struct acpipchb_softc *,
				      struct pcibus_attach_args *);

CFATTACH_DECL_NEW(acpipchb, sizeof(struct acpipchb_softc),
	acpipchb_match, acpipchb_attach, NULL, NULL);

static const char * const compatible[] = {
	"PNP0A08",
	NULL
};

static int
acpipchb_match(device_t parent, cfdata_t cf, void *aux)
{
	struct acpi_attach_args *aa = aux;

	if (aa->aa_node->ad_type != ACPI_TYPE_DEVICE)
		return 0;

	return acpi_match_hid(aa->aa_node->ad_devinfo, compatible);
}

static void
acpipchb_attach(device_t parent, device_t self, void *aux)
{
	struct acpipchb_softc * const sc = device_private(self);
	struct acpi_attach_args *aa = aux;
	struct pcibus_attach_args pba;
	ACPI_INTEGER seg, nomsi;
	ACPI_STATUS rv;
	uint16_t bus_start;

	sc->sc_dev = self;
	sc->sc_memt = aa->aa_memt;
	sc->sc_handle = aa->aa_node->ad_handle;

	/*
	 * First try to derive the base bus number from _CRS. If that fails,
	 * try _BBN. If that fails too, assume bus 0.
	 */
	if (ACPI_SUCCESS(acpi_pcidev_pciroot_bus(sc->sc_handle, &bus_start))) {
		sc->sc_bus = bus_start;
	} else {
		rv = acpi_eval_integer(sc->sc_handle, "_BBN", &sc->sc_bus);
		if (ACPI_FAILURE(rv)) {
			sc->sc_bus = 0;
		}
	}

	if (ACPI_FAILURE(acpi_eval_integer(sc->sc_handle, "_SEG", &seg))) {
		seg = 0;
	}

	if (ACPI_FAILURE(acpi_dsd_integer(sc->sc_handle, "linux,pcie-nomsi",
	    &nomsi))) {
		nomsi = 0;
	}

	aprint_naive("\n");
	aprint_normal(": PCI Express Host Bridge\n");

	acpi_claim_childdevs(self, aa->aa_node);

	memset(&pba, 0, sizeof(pba));
	pba.pba_flags = aa->aa_pciflags &
			~(PCI_FLAGS_MEM_OKAY | PCI_FLAGS_IO_OKAY);
	if (nomsi) {
		pba.pba_flags &= ~(PCI_FLAGS_MSI_OKAY | PCI_FLAGS_MSIX_OKAY);
	}
	pba.pba_memt = 0;
	pba.pba_iot = 0;
	pba.pba_dmat = aa->aa_dmat;
#ifdef _PCI_HAVE_DMA64
	pba.pba_dmat64 = aa->aa_dmat64;
#endif
	pba.pba_pc = aa->aa_pc;
	pba.pba_bus = sc->sc_bus;

	acpipchb_setup_ranges(sc, &pba);
	acpipchb_setup_quirks(sc, &pba);

	acpipchb_configure_bus(sc, &pba);

	config_found(self, &pba, pcibusprint,
	    CFARGS(.devhandle = device_handle(self)));
}

static void
acpipchb_configure_bus(struct acpipchb_softc *sc, struct pcibus_attach_args *pba)
{
	struct arm32_pci_chipset *md_pc =
	    (struct arm32_pci_chipset *)pba->pba_pc;
	struct acpi_pci_context *ap = md_pc->pc_conf_v;
	struct pciconf_resources *pcires;
	ACPI_STATUS rv;
	int error, val;

	if (!acpi_pci_ignore_boot_config(sc->sc_handle)) {
		return;
	}
	if (get_bootconf_option(boot_args, "nopciconf",
				BOOTOPT_TYPE_BOOLEAN, &val) && val) {
		return;
	}

	if ((ap->ap_flags & ACPI_PCI_FLAG_NO_MCFG) != 0) {
		pcires = pciconf_resource_init();
		rv = AcpiWalkResources(sc->sc_handle, "_CRS",
		    acpimcfg_configure_bus_cb, pcires);
		if (ACPI_FAILURE(rv)) {
			error = ENXIO;
		} else {
			error = pci_configure_bus(pba->pba_pc, pcires, ap->ap_bus,
			    PCIHOST_CACHELINE_SIZE);
		}
		pciconf_resource_fini(pcires);
	} else {
		error = acpimcfg_configure_bus(sc->sc_dev, pba->pba_pc, sc->sc_handle,
		    sc->sc_bus, PCIHOST_CACHELINE_SIZE);
	}

	if (error != 0) {
		aprint_error_dev(sc->sc_dev, "failed to configure bus, error %d\n",
		    error);
	}
}

struct acpipchb_setup_ranges_args {
	struct acpipchb_softc *sc;
	struct pcibus_attach_args *pba;
};

static int
acpipchb_bus_space_map(void *t, bus_addr_t bpa, bus_size_t size, int flag,
    bus_space_handle_t *bshp)
{
	struct acpipchb_bus_space * const abs = t;
	int i;

	if (size == 0)
		return ERANGE;

	if ((abs->flags & PCI_FLAGS_IO_OKAY) != 0) {
		/* Force strongly ordered mapping for all I/O space */
		flag = _ARM_BUS_SPACE_MAP_STRONGLY_ORDERED;
	}

	for (i = 0; i < abs->nrange; i++) {
		struct acpipchb_bus_range * const range = &abs->range[i];
		if (bpa >= range->min && bpa + size - 1 <= range->max) {
			return abs->map(t, bpa + range->offset, size,
					flag, bshp);
		}
	}

	return ERANGE;
}

static ACPI_STATUS
acpipchb_setup_ranges_cb(ACPI_RESOURCE *res, void *ctx)
{
	struct acpipchb_setup_ranges_args * const args = ctx;
	struct acpipchb_softc * const sc = args->sc;
	struct pcibus_attach_args *pba = args->pba;
	struct acpipchb_bus_space *abs;
	struct acpipchb_bus_range *range;
	const char *range_type;
	u_int pci_flags;

	if (res->Type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
	    res->Type != ACPI_RESOURCE_TYPE_ADDRESS64) {
		return AE_OK;
	}

	switch (res->Data.Address.ResourceType) {
	case ACPI_IO_RANGE:
		abs = &sc->sc_pciio_bst;
		range_type = "I/O";
		pci_flags = PCI_FLAGS_IO_OKAY;
		break;
	case ACPI_MEMORY_RANGE:
		abs = &sc->sc_pcimem_bst;
		range_type = "MEM";
		pci_flags = PCI_FLAGS_MEM_OKAY;
		break;
	default:
		return AE_OK;
	}

	if (abs->nrange == ACPIPCHB_MAX_RANGES) {
		aprint_error_dev(sc->sc_dev,
		    "maximum number of ranges reached (ACPIPCHB_MAX_RANGES)\n");
		return AE_LIMIT;
	}

	range = &abs->range[abs->nrange];
	switch (res->Type) {
	case ACPI_RESOURCE_TYPE_ADDRESS32:
		range->min = res->Data.Address32.Address.Minimum;
		range->max = res->Data.Address32.Address.Maximum;
		range->offset = res->Data.Address32.Address.TranslationOffset;
		break;
	case ACPI_RESOURCE_TYPE_ADDRESS64:
		range->min = res->Data.Address64.Address.Minimum;
		range->max = res->Data.Address64.Address.Maximum;
		range->offset = res->Data.Address64.Address.TranslationOffset;
		break;
	default:
		return AE_OK;
	}
	abs->nrange++;

	aprint_debug_dev(sc->sc_dev, "PCI %s [%#lx-%#lx] -> %#lx\n",
	    range_type, range->min, range->max, range->offset);

	if ((pba->pba_flags & pci_flags) == 0) {
		abs->bs = *sc->sc_memt;
		abs->bs.bs_cookie = abs;
		abs->map = abs->bs.bs_map;
		abs->flags = pci_flags;
		abs->bs.bs_map = acpipchb_bus_space_map;
		if ((pci_flags & PCI_FLAGS_IO_OKAY) != 0) {
			pba->pba_iot = &abs->bs;
		} else if ((pci_flags & PCI_FLAGS_MEM_OKAY) != 0) {
			pba->pba_memt = &abs->bs;
		}
		pba->pba_flags |= pci_flags;
	}

	return AE_OK;
}

static void
acpipchb_setup_ranges(struct acpipchb_softc *sc, struct pcibus_attach_args *pba)
{
	struct acpipchb_setup_ranges_args args;

	args.sc = sc;
	args.pba = pba;

	AcpiWalkResources(sc->sc_handle, "_CRS", acpipchb_setup_ranges_cb,
	    &args);
}

static void
acpipchb_setup_quirks(struct acpipchb_softc *sc, struct pcibus_attach_args *pba)
{
	struct arm32_pci_chipset *md_pc =
	    (struct arm32_pci_chipset *)pba->pba_pc;
	struct acpi_pci_context *ap = md_pc->pc_conf_v;

	pba->pba_flags &= ~ap->ap_pciflags_clear;
}