+struct mmcfg_virt {
+ struct acpi_table_mcfg_config *cfg;
+ char __iomem *virt;
+};
+static struct mmcfg_virt *pci_mmcfg_virt;
+
+static char __iomem *get_virt(unsigned int seg, unsigned bus)
+{
+ int cfg_num = -1;
+ struct acpi_table_mcfg_config *cfg;
+
+ while (1) {
+ ++cfg_num;
+ if (cfg_num >= pci_mmcfg_config_num)
+ break;
+ cfg = pci_mmcfg_virt[cfg_num].cfg;
+ if (cfg->pci_segment_group_number != seg)
+ continue;
+ if ((cfg->start_bus_number <= bus) &&
+ (cfg->end_bus_number >= bus))
+ return pci_mmcfg_virt[cfg_num].virt;
+ }
+
+ /* Handle more broken MCFG tables on Asus etc.
+ They only contain a single entry for bus 0-0. Assume
+ this applies to all busses. */
+ cfg = &pci_mmcfg_config[0];
+ if (pci_mmcfg_config_num == 1 &&
+ cfg->pci_segment_group_number == 0 &&
+ (cfg->start_bus_number | cfg->end_bus_number) == 0)
+ return pci_mmcfg_virt[0].virt;
+
+ /* Fall back to type 0 */
+ return NULL;
+}