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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.
*
* copied from Linux
*/
#include <xen/config.h>
#include <xen/init.h>
#include <xen/mm.h>
#include <xen/acpi.h>
#include <xen/xmalloc.h>
#include <xen/pci.h>
#include <xen/pci_regs.h>
#include <xen/iommu.h>
#include <xen/rangeset.h>
#include "mmconfig.h"
/* Static virtual mapping of the MMCONFIG aperture */
struct mmcfg_virt {
struct acpi_mcfg_allocation *cfg;
char __iomem *virt;
};
static struct mmcfg_virt *pci_mmcfg_virt;
static unsigned int mmcfg_pci_segment_shift;
static char __iomem *get_virt(unsigned int seg, unsigned int *bus)
{
struct acpi_mcfg_allocation *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)) {
*bus -= cfg->start_bus_number;
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 + ((bus << 20) | (devfn << 12));
}
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;
}
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 void __iomem *mcfg_ioremap(const struct acpi_mcfg_allocation *cfg,
unsigned long idx, unsigned int prot)
{
unsigned long virt, size;
virt = PCI_MCFG_VIRT_START + (idx << mmcfg_pci_segment_shift) +
(cfg->start_bus_number << 20);
size = (cfg->end_bus_number - cfg->start_bus_number + 1) << 20;
if (virt + size < virt || virt + size > PCI_MCFG_VIRT_END)
return NULL;
if (map_pages_to_xen(virt,
(cfg->address >> PAGE_SHIFT) +
(cfg->start_bus_number << (20 - PAGE_SHIFT)),
size >> PAGE_SHIFT, prot))
return NULL;
return (void __iomem *) virt;
}
void arch_pci_ro_device(int seg, int bdf)
{
unsigned int idx, bus = PCI_BUS(bdf);
for (idx = 0; idx < pci_mmcfg_config_num; ++idx) {
const struct acpi_mcfg_allocation *cfg = pci_mmcfg_virt[idx].cfg;
unsigned long mfn = (cfg->address >> PAGE_SHIFT) + bdf;
if (!pci_mmcfg_virt[idx].virt || cfg->pci_segment != seg ||
cfg->start_bus_number > bus || cfg->end_bus_number < bus)
continue;
if (rangeset_add_singleton(mmio_ro_ranges, mfn))
printk(XENLOG_ERR
"%04x:%02x:%02x.%u: could not mark MCFG (mfn %#lx) read-only\n",
cfg->pci_segment, bus, PCI_SLOT(bdf), PCI_FUNC(bdf),
mfn);
}
}
int pci_mmcfg_arch_enable(unsigned int idx)
{
const typeof(pci_mmcfg_config[0]) *cfg = pci_mmcfg_virt[idx].cfg;
const unsigned long *ro_map = pci_get_ro_map(cfg->pci_segment);
if (pci_mmcfg_virt[idx].virt)
return 0;
pci_mmcfg_virt[idx].virt = mcfg_ioremap(cfg, idx, PAGE_HYPERVISOR_NOCACHE);
if (!pci_mmcfg_virt[idx].virt) {
printk(KERN_ERR "PCI: Cannot map MCFG aperture for segment %04x\n",
cfg->pci_segment);
return -ENOMEM;
}
printk(KERN_INFO "PCI: Using MCFG for segment %04x bus %02x-%02x\n",
cfg->pci_segment, cfg->start_bus_number, cfg->end_bus_number);
if (ro_map) {
unsigned int bdf = PCI_BDF(cfg->start_bus_number, 0, 0);
unsigned int end = PCI_BDF(cfg->end_bus_number, -1, -1);
while ((bdf = find_next_bit(ro_map, end + 1, bdf)) <= end) {
arch_pci_ro_device(cfg->pci_segment, bdf);
if (bdf++ == end)
break;
}
}
return 0;
}
void pci_mmcfg_arch_disable(unsigned int idx)
{
const typeof(pci_mmcfg_config[0]) *cfg = pci_mmcfg_virt[idx].cfg;
pci_mmcfg_virt[idx].virt = NULL;
/*
* Don't use destroy_xen_mappings() here, or make sure that at least
* the necessary L4 entries get populated (so that they get properly
* propagated to guest domains' page tables).
*/
mcfg_ioremap(cfg, idx, 0);
printk(KERN_WARNING "PCI: Not using MCFG for segment %04x bus %02x-%02x\n",
cfg->pci_segment, cfg->start_bus_number, cfg->end_bus_number);
}
int __init pci_mmcfg_arch_init(void)
{
int i;
if (pci_mmcfg_virt)
return 0;
pci_mmcfg_virt = xzalloc_array(struct mmcfg_virt, pci_mmcfg_config_num);
if (pci_mmcfg_virt == NULL) {
printk(KERN_ERR "PCI: Can not allocate memory for mmconfig structures\n");
pci_mmcfg_config_num = 0;
return 0;
}
for (i = 0; i < pci_mmcfg_config_num; ++i) {
pci_mmcfg_virt[i].cfg = &pci_mmcfg_config[i];
while (pci_mmcfg_config[i].end_bus_number >> mmcfg_pci_segment_shift)
++mmcfg_pci_segment_shift;
}
mmcfg_pci_segment_shift += 20;
return 1;
}
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