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/*
* direct.c - Low-level direct PCI config space access
*/
#include <linux/pci.h>
#include <linux/init.h>
#include "pci.h"
#include <asm/xen-public/xen.h>
#include <asm/xen-public/physdev.h>
/*
* Functions for accessing PCI configuration space with type xen accesses
*/
static int pci_conf_read (int seg, int bus, int devfn, int reg, int len, u32 *value)
{
unsigned long flags;
physdev_op_t op;
int ret;
if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
return -EINVAL;
spin_lock_irqsave(&pci_config_lock, flags);
op.cmd = PHYSDEVOP_PCI_CFGREG_READ;
op.u.pci_cfgreg_read.bus = bus;
op.u.pci_cfgreg_read.dev = (devfn & ~0x7) >> 3;
op.u.pci_cfgreg_read.func = devfn & 0x7;
op.u.pci_cfgreg_read.reg = reg;
op.u.pci_cfgreg_read.len = len;
ret = HYPERVISOR_physdev_op(&op);
if (ret == 0)
*value = op.u.pci_cfgreg_read.value;
spin_unlock_irqrestore(&pci_config_lock, flags);
return ret;
}
static int pci_conf_write (int seg, int bus, int devfn, int reg, int len, u32 value)
{
unsigned long flags;
physdev_op_t op;
int ret;
if ((bus > 255) || (devfn > 255) || (reg > 255))
return -EINVAL;
spin_lock_irqsave(&pci_config_lock, flags);
op.cmd = PHYSDEVOP_PCI_CFGREG_WRITE;
op.u.pci_cfgreg_write.bus = bus;
op.u.pci_cfgreg_write.dev = (devfn & ~0x7) >> 3;
op.u.pci_cfgreg_write.func = devfn & 0x7;
op.u.pci_cfgreg_write.reg = reg;
op.u.pci_cfgreg_write.len = len;
op.u.pci_cfgreg_write.value = value;
ret = HYPERVISOR_physdev_op(&op);
spin_unlock_irqrestore(&pci_config_lock, flags);
return ret;
}
struct pci_raw_ops pci_direct_xen = {
.read = pci_conf_read,
.write = pci_conf_write,
};
static int __init pci_direct_init(void)
{
printk(KERN_INFO "PCI: Using configuration type Xen\n");
raw_pci_ops = &pci_direct_xen;
return 0;
}
arch_initcall(pci_direct_init);
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