// PCI config space access functions.
//
// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
// Copyright (C) 2002  MandrakeSoft S.A.
//
// This file may be distributed under the terms of the GNU LGPLv3 license.

#include "malloc.h" // malloc_tmp
#include "output.h" // dprintf
#include "pci.h" // pci_config_writel
#include "pci_regs.h" // PCI_VENDOR_ID
#include "romfile.h" // romfile_loadint
#include "string.h" // memset
#include "util.h" // udelay
#include "x86.h" // outl

void pci_config_writel(u16 bdf, u32 addr, u32 val)
{
    outl(0x80000000 | (bdf << 8) | (addr & 0xfc), PORT_PCI_CMD);
    outl(val, PORT_PCI_DATA);
}

void pci_config_writew(u16 bdf, u32 addr, u16 val)
{
    outl(0x80000000 | (bdf << 8) | (addr & 0xfc), PORT_PCI_CMD);
    outw(val, PORT_PCI_DATA + (addr & 2));
}

void pci_config_writeb(u16 bdf, u32 addr, u8 val)
{
    outl(0x80000000 | (bdf << 8) | (addr & 0xfc), PORT_PCI_CMD);
    outb(val, PORT_PCI_DATA + (addr & 3));
}

u32 pci_config_readl(u16 bdf, u32 addr)
{
    outl(0x80000000 | (bdf << 8) | (addr & 0xfc), PORT_PCI_CMD);
    return inl(PORT_PCI_DATA);
}

u16 pci_config_readw(u16 bdf, u32 addr)
{
    outl(0x80000000 | (bdf << 8) | (addr & 0xfc), PORT_PCI_CMD);
    return inw(PORT_PCI_DATA + (addr & 2));
}

u8 pci_config_readb(u16 bdf, u32 addr)
{
    outl(0x80000000 | (bdf << 8) | (addr & 0xfc), PORT_PCI_CMD);
    return inb(PORT_PCI_DATA + (addr & 3));
}

void
pci_config_maskw(u16 bdf, u32 addr, u16 off, u16 on)
{
    u16 val = pci_config_readw(bdf, addr);
    val = (val & ~off) | on;
    pci_config_writew(bdf, addr, val);
}

// Helper function for foreachbdf() macro - return next device
int
pci_next(int bdf, int bus)
{
    if (pci_bdf_to_fn(bdf) == 0
        && (pci_config_readb(bdf, PCI_HEADER_TYPE) & 0x80) == 0)
        // Last found device wasn't a multi-function device - skip to
        // the next device.
        bdf += 8;
    else
        bdf += 1;

    for (;;) {
        if (pci_bdf_to_bus(bdf) != bus)
            return -1;

        u16 v = pci_config_readw(bdf, PCI_VENDOR_ID);
        if (v != 0x0000 && v != 0xffff)
            // Device is present.
            return bdf;

        if (pci_bdf_to_fn(bdf) == 0)
            bdf += 8;
        else
            bdf += 1;
    }
}

struct hlist_head PCIDevices VARVERIFY32INIT;
int MaxPCIBus VARFSEG;

// Check if PCI is available at all
int
pci_probe_host(void)
{
    outl(0x80000000, PORT_PCI_CMD);
    if (inl(PORT_PCI_CMD) != 0x80000000) {
        dprintf(1, "Detected non-PCI system\n");
        return -1;
    }
    return 0;
}

// Find all PCI devices and populate PCIDevices linked list.
void
pci_probe_devices(void)
{
    dprintf(3, "PCI probe\n");
    struct pci_device *busdevs[256];
    memset(busdevs, 0, sizeof(busdevs));
    struct hlist_node **pprev = &PCIDevices.first;
    int extraroots = romfile_loadint("etc/extra-pci-roots", 0);
    int bus = -1, lastbus = 0, rootbuses = 0, count=0;
    while (bus < 0xff && (bus < MaxPCIBus || rootbuses < extraroots)) {
        bus++;
        int bdf;
        foreachbdf(bdf, bus) {
            // Create new pci_device struct and add to list.
            struct pci_device *dev = malloc_tmp(sizeof(*dev));
            if (!dev) {
                warn_noalloc();
                return;
            }
            memset(dev, 0, sizeof(*dev));
            hlist_add(&dev->node, pprev);
            pprev = &dev->node.next;
            count++;

            // Find parent device.
            int rootbus;
            struct pci_device *parent = busdevs[bus];
            if (!parent) {
                if (bus != lastbus)
                    rootbuses++;
                lastbus = bus;
                rootbus = rootbuses;
                if (bus > MaxPCIBus)
                    MaxPCIBus = bus;
            } else {
                rootbus = parent->rootbus;
            }

            // Populate pci_device info.
            dev->bdf = bdf;
            dev->parent = parent;
            dev->rootbus = rootbus;
            u32 vendev = pci_config_readl(bdf, PCI_VENDOR_ID);
            dev->vendor = vendev & 0xffff;
            dev->device = vendev >> 16;
            u32 classrev = pci_config_readl(bdf, PCI_CLASS_REVISION);
            dev->class = classrev >> 16;
            dev->prog_if = classrev >> 8;
            dev->revision = classrev & 0xff;
            dev->header_type = pci_config_readb(bdf, PCI_HEADER_TYPE);
            u8 v = dev->header_type & 0x7f;
            if (v == PCI_HEADER_TYPE_BRIDGE || v == PCI_HEADER_TYPE_CARDBUS) {
                u8 secbus = pci_config_readb(bdf, PCI_SECONDARY_BUS);
                dev->secondary_bus = secbus;
                if (secbus > bus && !busdevs[secbus])
                    busdevs[secbus] = dev;
                if (secbus > MaxPCIBus)
                    MaxPCIBus = secbus;
            }
            dprintf(4, "PCI device %02x:%02x.%x (vd=%04x:%04x c=%04x)\n"
                    , pci_bdf_to_bus(bdf), pci_bdf_to_dev(bdf)
                    , pci_bdf_to_fn(bdf)
                    , dev->vendor, dev->device, dev->class);
        }
    }
    dprintf(1, "Found %d PCI devices (max PCI bus is %02x)\n", count, MaxPCIBus);
}

// Search for a device with the specified vendor and device ids.
struct pci_device *
pci_find_device(u16 vendid, u16 devid)
{
    struct pci_device *pci;
    foreachpci(pci) {
        if (pci->vendor == vendid && pci->device == devid)
            return pci;
    }
    return NULL;
}

// Search for a device with the specified class id.
struct pci_device *
pci_find_class(u16 classid)
{
    struct pci_device *pci;
    foreachpci(pci) {
        if (pci->class == classid)
            return pci;
    }
    return NULL;
}

int pci_init_device(const struct pci_device_id *ids
                    , struct pci_device *pci, void *arg)
{
    while (ids->vendid || ids->class_mask) {
        if ((ids->vendid == PCI_ANY_ID || ids->vendid == pci->vendor) &&
            (ids->devid == PCI_ANY_ID || ids->devid == pci->device) &&
            !((ids->class ^ pci->class) & ids->class_mask)) {
            if (ids->func)
                ids->func(pci, arg);
            return 0;
        }
        ids++;
    }
    return -1;
}

struct pci_device *
pci_find_init_device(const struct pci_device_id *ids, void *arg)
{
    struct pci_device *pci;
    foreachpci(pci) {
        if (pci_init_device(ids, pci, arg) == 0)
            return pci;
    }
    return NULL;
}

u8 pci_find_capability(struct pci_device *pci, u8 cap_id)
{
    int i;
    u8 cap;
    u16 status = pci_config_readw(pci->bdf, PCI_STATUS);

    if (!(status & PCI_STATUS_CAP_LIST))
        return 0;

    cap = pci_config_readb(pci->bdf, PCI_CAPABILITY_LIST);
    for (i = 0; cap && i <= 0xff; i++) {
        if (pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_ID) == cap_id)
            return cap;
        cap = pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_NEXT);
    }

    return 0;
}

/* Test whether bridge support forwarding of transactions
 * of a specific type.
 * Note: disables bridge's window registers as a side effect.
 */
int pci_bridge_has_region(struct pci_device *pci,
        enum pci_region_type region_type)
{
    u8 base;

    switch (region_type) {
        case PCI_REGION_TYPE_IO:
            base = PCI_IO_BASE;
            break;
        case PCI_REGION_TYPE_PREFMEM:
            base = PCI_PREF_MEMORY_BASE;
            break;
        default:
            /* Regular memory support is mandatory */
            return 1;
    }

    pci_config_writeb(pci->bdf, base, 0xFF);

    return pci_config_readb(pci->bdf, base) != 0;
}

void
pci_reboot(void)
{
    u8 v = inb(PORT_PCI_REBOOT) & ~6;
    outb(v|2, PORT_PCI_REBOOT); /* Request hard reset */
    udelay(50);
    outb(v|6, PORT_PCI_REBOOT); /* Actually do the reset */
    udelay(50);
}