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/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index af5018f3d7c35a37694f2fa503163eeac291e301..b2652e95b3d76e518f37f7a1dbc9c4a06035c560 100644 (file)
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -100,6 +100,7 @@ struct pci_raw_ops {
 extern const struct pci_raw_ops *raw_pci_ops;
 extern const struct pci_raw_ops *raw_pci_ext_ops;
 
+extern const struct pci_raw_ops pci_mmcfg;
 extern const struct pci_raw_ops pci_direct_conf1;
 extern bool port_cf9_safe;
 

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 2bb885afe103c8d18a943021d070cd0af8f9cfd4..912b54b26d6aa7de4b882f150df612b38bccffb8 100644 (file)
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -13,6 +13,12 @@ struct pci_root_info {
        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 @@ void __init pci_acpi_crs_quirks(void)
               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 @@ static void __release_pci_root_info(struct pci_root_info *info)
 
        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 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
        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 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
                        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(

diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
index a22785deb50e415de5f55a8d48fb49d941b4c6a8..db63ac23e3d935d886948da8957bd372456cd19a 100644 (file)
--- a/arch/x86/pci/mmconfig_32.c
+++ b/arch/x86/pci/mmconfig_32.c
@@ -126,7 +126,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
        return 0;
 }
 
-static const struct pci_raw_ops pci_mmcfg = {
+const struct pci_raw_ops pci_mmcfg = {
        .read =         pci_mmcfg_read,
        .write =        pci_mmcfg_write,
 };

diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index ebefea5107a7be99de25358ab6a033538c74c26a..c206521fe98ea05848d7e6a62c6a61b9fd2325fd 100644 (file)
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -90,7 +90,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
        return 0;
 }
 
-static const struct pci_raw_ops pci_mmcfg = {
+const struct pci_raw_ops pci_mmcfg = {
        .read =         pci_mmcfg_read,
        .write =        pci_mmcfg_write,
 };