x86/PCI: update MMCONFIG information when hot-plugging PCI host bridges
This patch enhances x86 arch-specific code to update MMCONFIG information
when PCI host bridge hotplug event happens.
Reviewed-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 2bb885a..912b54b 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -13,6 +13,12 @@
unsigned int res_num;
struct resource *res;
struct pci_sysdata sd;
+#ifdef CONFIG_PCI_MMCONFIG
+ bool mcfg_added;
+ u16 segment;
+ u8 start_bus;
+ u8 end_bus;
+#endif
};
static bool pci_use_crs = true;
@@ -119,6 +125,81 @@
pci_use_crs ? "nocrs" : "use_crs");
}
+#ifdef CONFIG_PCI_MMCONFIG
+static int __devinit check_segment(u16 seg, struct device *dev, char *estr)
+{
+ if (seg) {
+ dev_err(dev,
+ "%s can't access PCI configuration "
+ "space under this host bridge.\n",
+ estr);
+ return -EIO;
+ }
+
+ /*
+ * Failure in adding MMCFG information is not fatal,
+ * just can't access extended configuration space of
+ * devices under this host bridge.
+ */
+ dev_warn(dev,
+ "%s can't access extended PCI configuration "
+ "space under this bridge.\n",
+ estr);
+
+ return 0;
+}
+
+static int __devinit setup_mcfg_map(struct pci_root_info *info,
+ u16 seg, u8 start, u8 end,
+ phys_addr_t addr)
+{
+ int result;
+ struct device *dev = &info->bridge->dev;
+
+ info->start_bus = start;
+ info->end_bus = end;
+ info->mcfg_added = false;
+
+ /* return success if MMCFG is not in use */
+ if (raw_pci_ext_ops && raw_pci_ext_ops != &pci_mmcfg)
+ return 0;
+
+ if (!(pci_probe & PCI_PROBE_MMCONF))
+ return check_segment(seg, dev, "MMCONFIG is disabled,");
+
+ result = pci_mmconfig_insert(dev, seg, start, end, addr);
+ if (result == 0) {
+ /* enable MMCFG if it hasn't been enabled yet */
+ if (raw_pci_ext_ops == NULL)
+ raw_pci_ext_ops = &pci_mmcfg;
+ info->mcfg_added = true;
+ } else if (result != -EEXIST)
+ return check_segment(seg, dev,
+ "fail to add MMCONFIG information,");
+
+ return 0;
+}
+
+static void teardown_mcfg_map(struct pci_root_info *info)
+{
+ if (info->mcfg_added) {
+ pci_mmconfig_delete(info->segment, info->start_bus,
+ info->end_bus);
+ info->mcfg_added = false;
+ }
+}
+#else
+static int __devinit setup_mcfg_map(struct pci_root_info *info,
+ u16 seg, u8 start, u8 end,
+ phys_addr_t addr)
+{
+ return 0;
+}
+static void teardown_mcfg_map(struct pci_root_info *info)
+{
+}
+#endif
+
static acpi_status
resource_to_addr(struct acpi_resource *resource,
struct acpi_resource_address64 *addr)
@@ -331,8 +412,11 @@
free_pci_root_info_res(info);
+ teardown_mcfg_map(info);
+
kfree(info);
}
+
static void release_pci_root_info(struct pci_host_bridge *bridge)
{
struct pci_root_info *info = bridge->release_data;
@@ -372,7 +456,7 @@
int domain = root->segment;
int busnum = root->secondary.start;
LIST_HEAD(resources);
- struct pci_bus *bus;
+ struct pci_bus *bus = NULL;
struct pci_sysdata *sd;
int node;
#ifdef CONFIG_ACPI_NUMA
@@ -438,8 +522,11 @@
x86_pci_root_bus_resources(busnum, &resources);
}
- bus = pci_create_root_bus(NULL, busnum, &pci_root_ops, sd,
- &resources);
+ if (!setup_mcfg_map(info, domain, (u8)root->secondary.start,
+ (u8)root->secondary.end, root->mcfg_addr))
+ bus = pci_create_root_bus(NULL, busnum, &pci_root_ops,
+ sd, &resources);
+
if (bus) {
pci_scan_child_bus(bus);
pci_set_host_bridge_release(