/******************************************************************************

 * pci.c

 *

 * Architecture-independent PCI access functions.

 */

#include <xen/init.h>

#include <xen/pci.h>

#include <xen/pci_regs.h>

int pci_find_cap_offset(u16 seg, u8 bus, u8 dev, u8 func, u8 cap)

{

    u8 id;

    int max_cap = 48;

    u8 pos = PCI_CAPABILITY_LIST;

    u16 status;

    status = pci_conf_read16(seg, bus, dev, func, PCI_STATUS);

    if ( (status & PCI_STATUS_CAP_LIST) == 0 )

        return 0;

    while ( max_cap-- )

    {

        pos = pci_conf_read8(seg, bus, dev, func, pos);

        if ( pos < 0x40 )

            break;

        pos &= ~3;

        id = pci_conf_read8(seg, bus, dev, func, pos + PCI_CAP_LIST_ID);

        if ( id == 0xff )

            break;

        else if ( id == cap )

            return pos;

        pos += PCI_CAP_LIST_NEXT;

    }

    return 0;

}

int pci_find_next_cap(u16 seg, u8 bus, unsigned int devfn, u8 pos, int cap)

{

    u8 id;

    int ttl = 48;

    while ( ttl-- )

    {

        pos = pci_conf_read8(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn), pos);

        if ( pos < 0x40 )

            break;

        pos &= ~3;

        id = pci_conf_read8(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),

                            pos + PCI_CAP_LIST_ID);

        if ( id == 0xff )

            break;

        if ( id == cap )

            return pos;

        pos += PCI_CAP_LIST_NEXT;

    }

    return 0;

}

/**

 * pci_find_ext_capability - Find an extended capability

 * @seg/@bus/@devfn: PCI device to query

 * @cap: capability code

 *

 * Returns the address of the requested extended capability structure

 * within the device's PCI configuration space or 0 if the device does

 * not support it.

 */

int pci_find_ext_capability(int seg, int bus, int devfn, int cap)

{

    return pci_find_next_ext_capability(seg, bus, devfn, 0, cap);

}

/**

 * pci_find_next_ext_capability - Find another extended capability

 * @seg/@bus/@devfn: PCI device to query

 * @pos: starting position

 * @cap: capability code

 *

 * Returns the address of the requested extended capability structure

 * within the device's PCI configuration space or 0 if the device does

 * not support it.

 */

int pci_find_next_ext_capability(int seg, int bus, int devfn, int start, int cap)

{

    u32 header;

    int ttl = 480; /* 3840 bytes, minimum 8 bytes per capability */

    int pos = max(start, 0x100);

    header = pci_conf_read32(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn), pos);

    /*

     * If we have no capabilities, this is indicated by cap ID,

     * cap version and next pointer all being 0.

     */

    if ( (header == 0) || (header == -1) )

        return 0;

    ASSERT(start != pos || PCI_EXT_CAP_ID(header) == cap);

    while ( ttl-- > 0 ) {

        if ( PCI_EXT_CAP_ID(header) == cap && pos != start )

            return pos;

        pos = PCI_EXT_CAP_NEXT(header);

        if ( pos < 0x100 )

            break;

        header = pci_conf_read32(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn), pos);

    }

    return 0;

}

const char *__init parse_pci(const char *s, unsigned int *seg_p,

                             unsigned int *bus_p, unsigned int *dev_p,

                             unsigned int *func_p)

{

    bool def_seg;

    return parse_pci_seg(s, seg_p, bus_p, dev_p, func_p, &def_seg);

}

const char *__init parse_pci_seg(const char *s, unsigned int *seg_p,

                                 unsigned int *bus_p, unsigned int *dev_p,

                                 unsigned int *func_p, bool *def_seg)

{

    unsigned long seg = simple_strtoul(s, &s, 16), bus, dev, func;

    if ( *s != ':' )

        return NULL;

    bus = simple_strtoul(s + 1, &s, 16);

    *def_seg = false;

    if ( *s == ':' )

        dev = simple_strtoul(s + 1, &s, 16);

    else

    {

        dev = bus;

        bus = seg;

        seg = 0;

        *def_seg = true;

    }

    if ( func_p )

    {

        if ( *s != '.' )

            return NULL;

        func = simple_strtoul(s + 1, &s, 0);

    }

    else

        func = 0;

    if ( seg != (seg_p ? (u16)seg : 0) ||

         bus != PCI_BUS(PCI_BDF2(bus, 0)) ||

         dev != PCI_SLOT(PCI_DEVFN(dev, 0)) ||

         func != PCI_FUNC(PCI_DEVFN(0, func)) )

        return NULL;

    if ( seg_p )

        *seg_p = seg;

    *bus_p = bus;

    *dev_p = dev;

    if ( func_p )

        *func_p = func;

    return s;

}