/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2000 Doug Rabson
 * 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>

#include <dev/agp/agppriv.h>
#include <dev/agp/agpreg.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>

#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/pmap.h>

#define REG_GARTCTRL    0
#define REG_APSIZE      1
#define REG_ATTBASE     2

struct agp_via_softc {
        struct agp_softc agp;
        u_int32_t       initial_aperture; /* aperture size at startup */
        struct agp_gatt *gatt;
        int             *regs;
};

static int via_v2_regs[] = { AGP_VIA_GARTCTRL, AGP_VIA_APSIZE,
    AGP_VIA_ATTBASE };
static int via_v3_regs[] = { AGP3_VIA_GARTCTRL, AGP3_VIA_APSIZE,
    AGP3_VIA_ATTBASE };

static const char*
agp_via_match(device_t dev)
{
        if (pci_get_class(dev) != PCIC_BRIDGE
            || pci_get_subclass(dev) != PCIS_BRIDGE_HOST)
                return NULL;

        if (agp_find_caps(dev) == 0)
                return NULL;

        switch (pci_get_devid(dev)) {
        case 0x01981106:
                return ("VIA 8763 (P4X600) host to PCI bridge");
        case 0x02591106:
                return ("VIA PM800/PN800/PM880/PN880 host to PCI bridge");
        case 0x02691106:
                return ("VIA KT880 host to PCI bridge");
        case 0x02961106:
                return ("VIA 3296 (P4M800) host to PCI bridge");
        case 0x03051106:
                return ("VIA 82C8363 (Apollo KT133x/KM133) host to PCI bridge");
        case 0x03141106:
                return ("VIA 3314 (P4M800CE) host to PCI bridge");
        case 0x03241106:
                return ("VIA VT3324 (CX700) host to PCI bridge");
        case 0x03271106:
                return ("VIA 3327 (P4M890) host to PCI bridge");
        case 0x03641106:
                return ("VIA 3364 (P4M900) host to PCI bridge");
        case 0x03911106:
                return ("VIA 8371 (Apollo KX133) host to PCI bridge");
        case 0x05011106:
                return ("VIA 8501 (Apollo MVP4) host to PCI bridge");
        case 0x05971106:
                return ("VIA 82C597 (Apollo VP3) host to PCI bridge");
        case 0x05981106:
                return ("VIA 82C598 (Apollo MVP3) host to PCI bridge");
        case 0x06011106:
                return ("VIA 8601 (Apollo ProMedia/PLE133Ta) host to PCI bridge");
        case 0x06051106:
                return ("VIA 82C694X (Apollo Pro 133A) host to PCI bridge");
        case 0x06911106:
                return ("VIA 82C691 (Apollo Pro) host to PCI bridge");
        case 0x30911106:
                return ("VIA 8633 (Pro 266) host to PCI bridge");
        case 0x30991106:
                return ("VIA 8367 (KT266/KY266x/KT333) host to PCI bridge");
        case 0x31011106:
                return ("VIA 8653 (Pro266T) host to PCI bridge");
        case 0x31121106:
                return ("VIA 8361 (KLE133) host to PCI bridge");
        case 0x31161106:
                return ("VIA XM266 (PM266/KM266) host to PCI bridge");
        case 0x31231106:
                return ("VIA 862x (CLE266) host to PCI bridge");
        case 0x31281106:
                return ("VIA 8753 (P4X266) host to PCI bridge");
        case 0x31481106:
                return ("VIA 8703 (P4M266x/P4N266) host to PCI bridge");
        case 0x31561106:
                return ("VIA XN266 (Apollo Pro266) host to PCI bridge");
        case 0x31681106:
                return ("VIA 8754 (PT800) host to PCI bridge");
        case 0x31891106:
                return ("VIA 8377 (Apollo KT400/KT400A/KT600) host to PCI bridge");
        case 0x32051106:
                return ("VIA 8235/8237 (Apollo KM400/KM400A) host to PCI bridge");
        case 0x32081106:
                return ("VIA 8783 (PT890) host to PCI bridge");
        case 0x32581106:
                return ("VIA PT880 host to PCI bridge");
        case 0xb1981106:
                return ("VIA VT83xx/VT87xx/KTxxx/Px8xx host to PCI bridge");
        }

        return NULL;
}

static int
agp_via_probe(device_t dev)
{
        const char *desc;

        if (resource_disabled("agp", device_get_unit(dev)))
                return (ENXIO);
        desc = agp_via_match(dev);
        if (desc) {
                device_set_desc(dev, desc);
                return BUS_PROBE_DEFAULT;
        }

        return ENXIO;
}

static int
agp_via_attach(device_t dev)
{
        struct agp_via_softc *sc = device_get_softc(dev);
        struct agp_gatt *gatt;
        int error;
        u_int32_t agpsel;
        u_int32_t capid;

        sc->regs = via_v2_regs;

        /* Look at the capability register to see if we handle AGP3 */
        capid = pci_read_config(dev, agp_find_caps(dev) + AGP_CAPID, 4);
        if (((capid >> 20) & 0x0f) >= 3) { 
                agpsel = pci_read_config(dev, AGP_VIA_AGPSEL, 1);
                if ((agpsel & (1 << 1)) == 0)
                        sc->regs = via_v3_regs;
        }

        error = agp_generic_attach(dev);
        if (error)
                return error;

        sc->initial_aperture = AGP_GET_APERTURE(dev);

        for (;;) {
                gatt = agp_alloc_gatt(dev);
                if (gatt)
                        break;

                /*
                 * Probably contigmalloc failure. Try reducing the
                 * aperture so that the gatt size reduces.
                 */
                if (AGP_SET_APERTURE(dev, AGP_GET_APERTURE(dev) / 2)) {
                        agp_generic_detach(dev);
                        return ENOMEM;
                }
        }
        sc->gatt = gatt;

        if (sc->regs == via_v2_regs) {
                /* Install the gatt. */
                pci_write_config(dev, sc->regs[REG_ATTBASE], gatt->ag_physical | 3, 4);
                
                /* Enable the aperture. */
                pci_write_config(dev, sc->regs[REG_GARTCTRL], 0x0f, 4);
        } else {
                u_int32_t gartctrl;

                /* Install the gatt. */
                pci_write_config(dev, sc->regs[REG_ATTBASE], gatt->ag_physical, 4);
                
                /* Enable the aperture. */
                gartctrl = pci_read_config(dev, sc->regs[REG_GARTCTRL], 4);
                pci_write_config(dev, sc->regs[REG_GARTCTRL], gartctrl | (3 << 7), 4);
        }

        device_printf(dev, "aperture size is %dM\n",
                sc->initial_aperture / 1024 / 1024);

        return 0;
}

static int
agp_via_detach(device_t dev)
{
        struct agp_via_softc *sc = device_get_softc(dev);

        agp_free_cdev(dev);

        pci_write_config(dev, sc->regs[REG_GARTCTRL], 0, 4);
        pci_write_config(dev, sc->regs[REG_ATTBASE], 0, 4);
        AGP_SET_APERTURE(dev, sc->initial_aperture);
        agp_free_gatt(sc->gatt);
        agp_free_res(dev);

        return 0;
}

static u_int32_t
agp_via_get_aperture(device_t dev)
{
        struct agp_via_softc *sc = device_get_softc(dev);
        u_int32_t apsize;

        if (sc->regs == via_v2_regs) {
                apsize = pci_read_config(dev, sc->regs[REG_APSIZE], 1);

                /*
                 * The size is determined by the number of low bits of
                 * register APBASE which are forced to zero. The low 20 bits
                 * are always forced to zero and each zero bit in the apsize
                 * field just read forces the corresponding bit in the 27:20
                 * to be zero. We calculate the aperture size accordingly.
                 */
                return (((apsize ^ 0xff) << 20) | ((1 << 20) - 1)) + 1;
        } else {
                apsize = pci_read_config(dev, sc->regs[REG_APSIZE], 2) & 0xfff;
                switch (apsize) {
                case 0x800:
                        return 0x80000000;
                case 0xc00:
                        return 0x40000000;
                case 0xe00:
                        return 0x20000000;
                case 0xf00:
                        return 0x10000000;
                case 0xf20:
                        return 0x08000000;
                case 0xf30:
                        return 0x04000000;
                case 0xf38:
                        return 0x02000000;
                case 0xf3c:
                        return 0x01000000;
                case 0xf3e:
                        return 0x00800000;
                case 0xf3f:
                        return 0x00400000;
                default:
                        device_printf(dev, "Invalid aperture setting 0x%x\n",
                            pci_read_config(dev, sc->regs[REG_APSIZE], 2));
                        return 0;
                }
        }
}

static int
agp_via_set_aperture(device_t dev, u_int32_t aperture)
{
        struct agp_via_softc *sc = device_get_softc(dev);
        u_int32_t apsize, key, val;

        if (sc->regs == via_v2_regs) {
                /*
                 * Reverse the magic from get_aperture.
                 */
                apsize = ((aperture - 1) >> 20) ^ 0xff;

                /*
                 * Double check for sanity.
                 */
                if ((((apsize ^ 0xff) << 20) | ((1 << 20) - 1)) + 1 != aperture)
                        return EINVAL;

                pci_write_config(dev, sc->regs[REG_APSIZE], apsize, 1);
        } else {
                switch (aperture) {
                case 0x80000000:
                        key = 0x800;
                        break;
                case 0x40000000:
                        key = 0xc00;
                        break;
                case 0x20000000:
                        key = 0xe00;
                        break;
                case 0x10000000:
                        key = 0xf00;
                        break;
                case 0x08000000:
                        key = 0xf20;
                        break;
                case 0x04000000:
                        key = 0xf30;
                        break;
                case 0x02000000:
                        key = 0xf38;
                        break;
                case 0x01000000:
                        key = 0xf3c;
                        break;
                case 0x00800000:
                        key = 0xf3e;
                        break;
                case 0x00400000:
                        key = 0xf3f;
                        break;
                default:
                        device_printf(dev, "Invalid aperture size (%dMb)\n",
                            aperture / 1024 / 1024);
                        return EINVAL;
                }
                val = pci_read_config(dev, sc->regs[REG_APSIZE], 2);
                pci_write_config(dev, sc->regs[REG_APSIZE], 
                    ((val & ~0xfff) | key), 2);
        }
        return 0;
}

static int
agp_via_bind_page(device_t dev, vm_offset_t offset, vm_offset_t physical)
{
        struct agp_via_softc *sc = device_get_softc(dev);

        if (offset >= (sc->gatt->ag_entries << AGP_PAGE_SHIFT))
                return EINVAL;

        sc->gatt->ag_virtual[offset >> AGP_PAGE_SHIFT] = physical;
        return 0;
}

static int
agp_via_unbind_page(device_t dev, vm_offset_t offset)
{
        struct agp_via_softc *sc = device_get_softc(dev);

        if (offset >= (sc->gatt->ag_entries << AGP_PAGE_SHIFT))
                return EINVAL;

        sc->gatt->ag_virtual[offset >> AGP_PAGE_SHIFT] = 0;
        return 0;
}

static void
agp_via_flush_tlb(device_t dev)
{
        struct agp_via_softc *sc = device_get_softc(dev);
        u_int32_t gartctrl;

        if (sc->regs == via_v2_regs) {
                pci_write_config(dev, sc->regs[REG_GARTCTRL], 0x8f, 4);
                pci_write_config(dev, sc->regs[REG_GARTCTRL], 0x0f, 4);
        } else {
                gartctrl = pci_read_config(dev, sc->regs[REG_GARTCTRL], 4);
                pci_write_config(dev, sc->regs[REG_GARTCTRL], gartctrl &
                    ~(1 << 7), 4);
                pci_write_config(dev, sc->regs[REG_GARTCTRL], gartctrl, 4);
        }

}

static device_method_t agp_via_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         agp_via_probe),
        DEVMETHOD(device_attach,        agp_via_attach),
        DEVMETHOD(device_detach,        agp_via_detach),
        DEVMETHOD(device_shutdown,      bus_generic_shutdown),
        DEVMETHOD(device_suspend,       bus_generic_suspend),
        DEVMETHOD(device_resume,        bus_generic_resume),

        /* AGP interface */
        DEVMETHOD(agp_get_aperture,     agp_via_get_aperture),
        DEVMETHOD(agp_set_aperture,     agp_via_set_aperture),
        DEVMETHOD(agp_bind_page,        agp_via_bind_page),
        DEVMETHOD(agp_unbind_page,      agp_via_unbind_page),
        DEVMETHOD(agp_flush_tlb,        agp_via_flush_tlb),
        DEVMETHOD(agp_enable,           agp_generic_enable),
        DEVMETHOD(agp_alloc_memory,     agp_generic_alloc_memory),
        DEVMETHOD(agp_free_memory,      agp_generic_free_memory),
        DEVMETHOD(agp_bind_memory,      agp_generic_bind_memory),
        DEVMETHOD(agp_unbind_memory,    agp_generic_unbind_memory),
        DEVMETHOD_END
};

static driver_t agp_via_driver = {
        "agp",
        agp_via_methods,
        sizeof(struct agp_via_softc),
};

DRIVER_MODULE(agp_via, hostb, agp_via_driver, 0, 0);
MODULE_DEPEND(agp_via, agp, 1, 1, 1);
MODULE_DEPEND(agp_via, pci, 1, 1, 1);