pci.c

xen虚拟机源代码安装包

/******************************************************************************
 * pci.c
 * 
 * PCI access functions.
 */

#include <xen/config.h>
#include <xen/pci.h>
#include <xen/pci_regs.h>
#include <xen/spinlock.h>
#include <asm/io.h>

#define PCI_CONF_ADDRESS(bus, dev, func, reg) \
    (0x80000000 | (bus << 16) | (dev << 11) | (func << 8) | (reg & ~3))

static DEFINE_SPINLOCK(pci_config_lock);

uint32_t pci_conf_read(uint32_t cf8, uint8_t offset, uint8_t bytes)
{
    unsigned long flags;
    uint32_t value;

    BUG_ON((offset + bytes) > 4);

    spin_lock_irqsave(&pci_config_lock, flags);

    outl(cf8, 0xcf8);

    switch ( bytes )
    {
    case 1:
        value = inb(0xcfc + offset);
        break;
    case 2:
        value = inw(0xcfc + offset);
        break;
    case 4:
        value = inl(0xcfc + offset);
        break;
    default:
        value = 0;
        BUG();
    }

    spin_unlock_irqrestore(&pci_config_lock, flags);

    return value;
}

void pci_conf_write(uint32_t cf8, uint8_t offset, uint8_t bytes, uint32_t data)
{
    unsigned long flags;

    BUG_ON((offset + bytes) > 4);

    spin_lock_irqsave(&pci_config_lock, flags);

    outl(cf8, 0xcf8);

    switch ( bytes )
    {
    case 1:
        outb((uint8_t)data, 0xcfc + offset);
        break;
    case 2:
        outw((uint16_t)data, 0xcfc + offset);
        break;
    case 4:
        outl(data, 0xcfc + offset);
        break;
    }

    spin_unlock_irqrestore(&pci_config_lock, flags);
}

uint8_t pci_conf_read8(
    unsigned int bus, unsigned int dev, unsigned int func, unsigned int reg)
{
    BUG_ON((bus > 255) || (dev > 31) || (func > 7) || (reg > 255));
    return pci_conf_read(PCI_CONF_ADDRESS(bus, dev, func, reg), reg & 3, 1);
}

uint16_t pci_conf_read16(
    unsigned int bus, unsigned int dev, unsigned int func, unsigned int reg)
{
    BUG_ON((bus > 255) || (dev > 31) || (func > 7) || (reg > 255));
    return pci_conf_read(PCI_CONF_ADDRESS(bus, dev, func, reg), reg & 2, 2);
}

uint32_t pci_conf_read32(
    unsigned int bus, unsigned int dev, unsigned int func, unsigned int reg)
{
    BUG_ON((bus > 255) || (dev > 31) || (func > 7) || (reg > 255));
    return pci_conf_read(PCI_CONF_ADDRESS(bus, dev, func, reg), 0, 4);
}

void pci_conf_write8(
    unsigned int bus, unsigned int dev, unsigned int func, unsigned int reg,
    uint8_t data)
{
    BUG_ON((bus > 255) || (dev > 31) || (func > 7) || (reg > 255));
    pci_conf_write(PCI_CONF_ADDRESS(bus, dev, func, reg), reg & 3, 1, data);
}

void pci_conf_write16(
    unsigned int bus, unsigned int dev, unsigned int func, unsigned int reg,
    uint16_t data)
{
    BUG_ON((bus > 255) || (dev > 31) || (func > 7) || (reg > 255));
    pci_conf_write(PCI_CONF_ADDRESS(bus, dev, func, reg), reg & 2, 2, data);
}

void pci_conf_write32(
    unsigned int bus, unsigned int dev, unsigned int func, unsigned int reg,
    uint32_t data)
{
    BUG_ON((bus > 255) || (dev > 31) || (func > 7) || (reg > 255));
    pci_conf_write(PCI_CONF_ADDRESS(bus, dev, func, reg), 0, 4, data);
}

int pci_find_cap_offset(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(bus, dev, func, PCI_STATUS);
    if ( (status & PCI_STATUS_CAP_LIST) == 0 )
        return 0;

    while ( max_cap-- )
    {
        pos = pci_conf_read8(bus, dev, func, pos);
        if ( pos < 0x40 )
            break;

        pos &= ~3;
        id = pci_conf_read8(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(u8 bus, unsigned int devfn, u8 pos, int cap)
{
    u8 id;
    int ttl = 48;

    while ( ttl-- )
    {
        pos = pci_conf_read8(bus, PCI_SLOT(devfn), PCI_FUNC(devfn), pos);
        if ( pos < 0x40 )
            break;

        pos &= ~3;
        id = pci_conf_read8(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;
}