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/*
* mmconfig.c - Low-level direct PCI config space access via MMCONFIG
*
* This is an 64bit optimized version that always keeps the full mmconfig
* space mapped. This allows lockless config space operation.
*/
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/bitmap.h>
#include <asm/e820.h>
#include <asm/pci_x86.h>
/* Static virtual mapping of the MMCONFIG aperture */
struct mmcfg_virt {
struct pci_mmcfg_region *cfg;
char __iomem *virt;
};
static struct mmcfg_virt *pci_mmcfg_virt;
static char __iomem *get_virt(unsigned int seg, unsigned bus)
{
struct pci_mmcfg_region *cfg;
int cfg_num;
for (cfg_num = 0; cfg_num < pci_mmcfg_config_num; cfg_num++) {
cfg = pci_mmcfg_virt[cfg_num].cfg;
if (cfg->pci_segment == seg &&
(cfg->start_bus_number <= bus) &&
(cfg->end_bus_number >= bus))
return pci_mmcfg_virt[cfg_num].virt;
}
/* Fall back to type 0 */
return NULL;
}
static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
{
char __iomem *addr;
addr = get_virt(seg, bus);
if (!addr)
return NULL;
return addr + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12));
}
static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *value)
{
char __iomem *addr;
/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
err: *value = -1;
return -EINVAL;
}
addr = pci_dev_base(seg, bus, devfn);
if (!addr)
goto err;
switch (len) {
case 1:
*value = mmio_config_readb(addr + reg);
break;
case 2:
*value = mmio_config_readw(addr + reg);
break;
case 4:
*value = mmio_config_readl(addr + reg);
break;
}
return 0;
}
static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 value)
{
char __iomem *addr;
/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
return -EINVAL;
addr = pci_dev_base(seg, bus, devfn);
if (!addr)
return -EINVAL;
switch (len) {
case 1:
mmio_config_writeb(addr + reg, value);
break;
case 2:
mmio_config_writew(addr + reg, value);
break;
case 4:
mmio_config_writel(addr + reg, value);
break;
}
return 0;
}
static struct pci_raw_ops pci_mmcfg = {
.read = pci_mmcfg_read,
.write = pci_mmcfg_write,
};
static void __iomem * __init mcfg_ioremap(struct pci_mmcfg_region *cfg)
{
void __iomem *addr;
u64 start, size;
int num_buses;
start = cfg->address + PCI_MMCFG_BUS_OFFSET(cfg->start_bus_number);
num_buses = cfg->end_bus_number - cfg->start_bus_number + 1;
size = PCI_MMCFG_BUS_OFFSET(num_buses);
addr = ioremap_nocache(start, size);
if (addr) {
printk(KERN_INFO "PCI: Using MMCONFIG at %Lx - %Lx\n",
start, start + size - 1);
addr -= PCI_MMCFG_BUS_OFFSET(cfg->start_bus_number);
}
return addr;
}
int __init pci_mmcfg_arch_init(void)
{
int i;
pci_mmcfg_virt = kzalloc(sizeof(*pci_mmcfg_virt) *
pci_mmcfg_config_num, GFP_KERNEL);
if (pci_mmcfg_virt == NULL) {
printk(KERN_ERR "PCI: Can not allocate memory for mmconfig structures\n");
return 0;
}
for (i = 0; i < pci_mmcfg_config_num; ++i) {
pci_mmcfg_virt[i].cfg = &pci_mmcfg_config[i];
pci_mmcfg_virt[i].virt = mcfg_ioremap(&pci_mmcfg_config[i]);
if (!pci_mmcfg_virt[i].virt) {
printk(KERN_ERR "PCI: Cannot map mmconfig aperture for "
"segment %d\n",
pci_mmcfg_config[i].pci_segment);
pci_mmcfg_arch_free();
return 0;
}
}
raw_pci_ext_ops = &pci_mmcfg;
return 1;
}
void __init pci_mmcfg_arch_free(void)
{
int i;
if (pci_mmcfg_virt == NULL)
return;
for (i = 0; i < pci_mmcfg_config_num; ++i) {
if (pci_mmcfg_virt[i].virt) {
iounmap(pci_mmcfg_virt[i].virt + PCI_MMCFG_BUS_OFFSET(pci_mmcfg_virt[i].cfg->start_bus_number));
pci_mmcfg_virt[i].virt = NULL;
pci_mmcfg_virt[i].cfg = NULL;
}
}
kfree(pci_mmcfg_virt);
pci_mmcfg_virt = NULL;
}
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