/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2018 Johannes Lundberg
 *
 * 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/bus.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>

#include <vm/vm.h>
/* XXX: enable this once the KPI is available */
/* #include <x86/physmem.h> */
#include <bus/pci/pci_cfgreg.h>
#include <machine/md_var.h>
#include <bus/pci/pcivar.h>
#include <bus/pci/pcireg.h>

#include <bus/pci/x86_64/pci_early_quirks.h>

#define MiB(v) ((unsigned long)(v) << 20)

struct pci_device_id {
        uint32_t        vendor;
        uint32_t        device;
        const struct intel_stolen_ops *data;
};

/*
 * These global variables are read by LinuxKPI.
 * LinuxKPI provide this information to the i915 driver.
 */
vm_paddr_t intel_graphics_stolen_base = 0;
vm_paddr_t intel_graphics_stolen_size = 0;
SYSCTL_U64(_hw, OID_AUTO, intel_graphics_stolen_base, CTLFLAG_RD,
    &intel_graphics_stolen_base, 0,
    "Base address of the intel graphics stolen memory.");
SYSCTL_U64(_hw, OID_AUTO, intel_graphics_stolen_size, CTLFLAG_RD,
    &intel_graphics_stolen_size, 0,
    "Size of the intel graphics stolen memory.");

/*
 * Intel early quirks functions
 */
static vm_paddr_t
intel_stolen_base_gen3(int bus, int slot, int func)
{
        uint32_t ctrl;
        vm_paddr_t val;

        ctrl = pci_cfgregread(bus, slot, func, INTEL_BSM, 4);
        val = ctrl & INTEL_BSM_MASK;
        return (val);
}

static vm_paddr_t
intel_stolen_base_gen11(int bus, int slot, int func)
{
        uint32_t ctrl;
        vm_paddr_t val;

        ctrl = pci_cfgregread(bus, slot, func, INTEL_GEN11_BSM_DW0, 4);
        val = ctrl & INTEL_BSM_MASK;
        val |= (uint64_t)pci_cfgregread(
            bus, slot, func, INTEL_GEN11_BSM_DW1, 4) << 32;
        return (val);
}

static vm_paddr_t
intel_stolen_size_gen3(int bus, int slot, int func)
{
        uint32_t ctrl;
        vm_paddr_t val;

        ctrl = pci_cfgregread(0, 0, 0, I830_GMCH_CTRL, 2);
        val = ctrl & I855_GMCH_GMS_MASK;

        switch (val) {
        case I855_GMCH_GMS_STOLEN_1M:
                return (MiB(1));
        case I855_GMCH_GMS_STOLEN_4M:
                return (MiB(4));
        case I855_GMCH_GMS_STOLEN_8M:
                return (MiB(8));
        case I855_GMCH_GMS_STOLEN_16M:
                return (MiB(16));
        case I855_GMCH_GMS_STOLEN_32M:
                return (MiB(32));
        case I915_GMCH_GMS_STOLEN_48M:
                return (MiB(48));
        case I915_GMCH_GMS_STOLEN_64M:
                return (MiB(64));
        case G33_GMCH_GMS_STOLEN_128M:
                return (MiB(128));
        case G33_GMCH_GMS_STOLEN_256M:
                return (MiB(256));
        case INTEL_GMCH_GMS_STOLEN_96M:
                return (MiB(96));
        case INTEL_GMCH_GMS_STOLEN_160M:
                return (MiB(160));
        case INTEL_GMCH_GMS_STOLEN_224M:
                return (MiB(224));
        case INTEL_GMCH_GMS_STOLEN_352M:
                return (MiB(352));
        }
        return (0);
}

static vm_paddr_t
intel_stolen_size_gen6(int bus, int slot, int func)
{
        uint32_t ctrl;
        vm_paddr_t val;

        ctrl = pci_cfgregread(bus, slot, func, SNB_GMCH_CTRL, 2);
        val = (ctrl >> SNB_GMCH_GMS_SHIFT) & SNB_GMCH_GMS_MASK;
        return (val * MiB(32));
}

static vm_paddr_t
intel_stolen_size_gen8(int bus, int slot, int func)
{
        uint32_t ctrl;
        vm_paddr_t val;

        ctrl = pci_cfgregread(bus, slot, func, SNB_GMCH_CTRL, 2);
        val = (ctrl >> BDW_GMCH_GMS_SHIFT) & BDW_GMCH_GMS_MASK;
        return (val * MiB(32));
}

static vm_paddr_t
intel_stolen_size_chv(int bus, int slot, int func)
{
        uint32_t ctrl;
        vm_paddr_t val;

        ctrl = pci_cfgregread(bus, slot, func, SNB_GMCH_CTRL, 2);
        val = (ctrl >> SNB_GMCH_GMS_SHIFT) & SNB_GMCH_GMS_MASK;

        /*
         * 0x0  to 0x10: 32MB increments starting at 0MB
         * 0x11 to 0x16: 4MB increments starting at 8MB
         * 0x17 to 0x1d: 4MB increments start at 36MB
         */
        if (val < 0x11)
                return (val * MiB(32));
        else if (val < 0x17)
                return ((val - 0x11) * MiB(4) + MiB(8));
        else
                return ((val - 0x17) * MiB(4) + MiB(36));
}

static vm_paddr_t
intel_stolen_size_gen9(int bus, int slot, int func)
{
        uint32_t ctrl;
        vm_paddr_t val;

        ctrl = pci_cfgregread(bus, slot, func, SNB_GMCH_CTRL, 2);
        val = (ctrl >> BDW_GMCH_GMS_SHIFT) & BDW_GMCH_GMS_MASK;

        /* 0x0  to 0xEF: 32MB increments starting at 0MB */
        /* 0xF0 to 0xFE: 4MB increments starting at 4MB */
        if (val < 0xF0)
                return (val * MiB(32));
        return ((val - 0xF0) * MiB(4) + MiB(4));
}

struct intel_stolen_ops {
        vm_paddr_t (*base)(int bus, int slot, int func);
        vm_paddr_t (*size)(int bus, int slot, int func);
};

static const struct intel_stolen_ops intel_stolen_ops_gen3 = {
        .base = intel_stolen_base_gen3,
        .size = intel_stolen_size_gen3,
};

static const struct intel_stolen_ops intel_stolen_ops_gen6 = {
        .base = intel_stolen_base_gen3,
        .size = intel_stolen_size_gen6,
};

static const struct intel_stolen_ops intel_stolen_ops_gen8 = {
        .base = intel_stolen_base_gen3,
        .size = intel_stolen_size_gen8,
};

static const struct intel_stolen_ops intel_stolen_ops_gen9 = {
        .base = intel_stolen_base_gen3,
        .size = intel_stolen_size_gen9,
};

static const struct intel_stolen_ops intel_stolen_ops_chv = {
        .base = intel_stolen_base_gen3,
        .size = intel_stolen_size_chv,
};

static const struct intel_stolen_ops intel_stolen_ops_gen11 = {
        .base = intel_stolen_base_gen11,
        .size = intel_stolen_size_gen9,
};

static const struct pci_device_id intel_ids[] = {
        INTEL_I915G_IDS(&intel_stolen_ops_gen3),
        INTEL_I915GM_IDS(&intel_stolen_ops_gen3),
        INTEL_I945G_IDS(&intel_stolen_ops_gen3),
        INTEL_I945GM_IDS(&intel_stolen_ops_gen3),
        INTEL_VLV_IDS(&intel_stolen_ops_gen6),
        INTEL_PINEVIEW_IDS(&intel_stolen_ops_gen3),
        INTEL_I965G_IDS(&intel_stolen_ops_gen3),
        INTEL_G33_IDS(&intel_stolen_ops_gen3),
        INTEL_I965GM_IDS(&intel_stolen_ops_gen3),
        INTEL_GM45_IDS(&intel_stolen_ops_gen3),
        INTEL_G45_IDS(&intel_stolen_ops_gen3),
        INTEL_IRONLAKE_D_IDS(&intel_stolen_ops_gen3),
        INTEL_IRONLAKE_M_IDS(&intel_stolen_ops_gen3),
        INTEL_SNB_D_IDS(&intel_stolen_ops_gen6),
        INTEL_SNB_M_IDS(&intel_stolen_ops_gen6),
        INTEL_IVB_M_IDS(&intel_stolen_ops_gen6),
        INTEL_IVB_D_IDS(&intel_stolen_ops_gen6),
        INTEL_HSW_IDS(&intel_stolen_ops_gen6),
        INTEL_BDW_IDS(&intel_stolen_ops_gen8),
        INTEL_CHV_IDS(&intel_stolen_ops_chv),
        INTEL_SKL_IDS(&intel_stolen_ops_gen9),
        INTEL_BXT_IDS(&intel_stolen_ops_gen9),
        INTEL_KBL_IDS(&intel_stolen_ops_gen9),
        INTEL_CFL_IDS(&intel_stolen_ops_gen9),
        INTEL_GLK_IDS(&intel_stolen_ops_gen9),
        INTEL_CNL_IDS(&intel_stolen_ops_gen9),
        INTEL_ICL_11_IDS(&intel_stolen_ops_gen11),
        INTEL_EHL_IDS(&intel_stolen_ops_gen11),
        INTEL_JSL_IDS(&intel_stolen_ops_gen11),
        INTEL_TGL_12_IDS(&intel_stolen_ops_gen11),
        INTEL_RKL_IDS(&intel_stolen_ops_gen11),
        INTEL_ADLS_IDS(&intel_stolen_ops_gen11),
        INTEL_ADLP_IDS(&intel_stolen_ops_gen11),
        INTEL_RPLS_IDS(&intel_stolen_ops_gen11),
};

/*
 * Buggy BIOS don't reserve memory for the GPU properly and the OS
 * can claim it before the GPU driver is loaded. This function will
 * check the registers for base and size of this memory and reserve
 * it for the GPU driver.
 * gen3 (2004) and newer devices are supported. Support for older hw
 * can be ported from Linux if needed.
 */
static void
intel_graphics_stolen(void)
{
        const struct intel_stolen_ops *ops;
        uint32_t vendor, device, class;
        int i;

        /* XXX: Scan bus instead of assuming 0:2:0? */
        const int bus = 0;
        const int slot = 2;
        const int func = 0;

        if (pci_cfgregopen() == 0)
                return;

        vendor = pci_cfgregread(bus, slot, func, PCIR_VENDOR, 2);
        if (vendor != PCI_VENDOR_INTEL)
                return;

        class = pci_cfgregread(bus, slot, func, PCIR_SUBCLASS, 2);
        if (class != PCI_CLASS_VGA)
                return;

        device = pci_cfgregread(bus, slot, func, PCIR_DEVICE, 2);
        if (device == 0xFFFF)
                return;

        for (i = 0; i < nitems(intel_ids); i++) {
                if (intel_ids[i].device != device)
                        continue;
                ops = intel_ids[i].data;
                intel_graphics_stolen_base = ops->base(bus, slot, func);
                intel_graphics_stolen_size = ops->size(bus, slot, func);
                break;
        }

        /* XXX: enable this once the KPI is available */
        /* phys_avail_reserve(intel_graphics_stolen_base, */
        /*     intel_graphics_stolen_base + intel_graphics_stolen_size); */
}

void
pci_early_quirks(void)
{
        intel_graphics_stolen();
}