x86/PCI: add pci_mmconfig_insert()/delete() for PCI root bridge hotplug

Introduce pci_mmconfig_insert()/pci_mmconfig_delete(), which will be used
to update MMCONFIG information when supporting PCI root bridge hotplug.

Reviewed-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

2 files changed, 109 insertions, 4 deletions

diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index df898ceab4d4..af5018f3d7c3 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -137,6 +137,10 @@ extern int __init pci_mmcfg_arch_init(void);
 extern void __init pci_mmcfg_arch_free(void);
 extern int __devinit pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg);
 extern void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg);
+extern int __devinit pci_mmconfig_insert(struct device *dev,
+                                         u16 seg, u8 start,
+                                         u8 end, phys_addr_t addr);
+extern int pci_mmconfig_delete(u16 seg, u8 start, u8 end);
 extern struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus);
 
 extern struct list_head pci_mmcfg_list;
diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 15a7abf5139c..19fc42b9f823 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -28,6 +28,7 @@
 /* Indicate if the mmcfg resources have been placed into the resource table. */
 static int __initdata pci_mmcfg_resources_inserted;
 static bool pci_mmcfg_running_state;
+static bool pci_mmcfg_arch_init_failed;
 static DEFINE_MUTEX(pci_mmcfg_lock);
 
 LIST_HEAD(pci_mmcfg_list);
@@ -92,10 +93,6 @@ static __devinit struct pci_mmcfg_region *pci_mmconfig_alloc(int segment,
                  "PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
         res->name = new->name;
 
-        printk(KERN_INFO PREFIX "MMCONFIG for domain %04x [bus %02x-%02x] at "
-               "%pR (base %#lx)\n", segment, start, end, &new->res,
-               (unsigned long) addr);
-
         return new;
 }
 
@@ -109,6 +106,11 @@ static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
                 mutex_lock(&pci_mmcfg_lock);
                 list_add_sorted(new);
                 mutex_unlock(&pci_mmcfg_lock);
+
+                printk(KERN_INFO PREFIX
+                       "MMCONFIG for domain %04x [bus %02x-%02x] at %pR "
+                       "(base %#lx)\n",
+                       segment, start, end, &new->res, (unsigned long)addr);
         }
 
         return new;
@@ -671,6 +673,7 @@ static void __init __pci_mmcfg_init(int early)
                  * the architecture mmcfg setup could not initialize.
                  */
                 pci_mmcfg_resources_inserted = 1;
+                pci_mmcfg_arch_init_failed = true;
         }
 }
 
@@ -713,3 +716,101 @@ static int __init pci_mmcfg_late_insert_resources(void)
  * with other system resources.
  */
 late_initcall(pci_mmcfg_late_insert_resources);
+
+/* Add MMCFG information for host bridges */
+int __devinit pci_mmconfig_insert(struct device *dev,
+                                  u16 seg, u8 start, u8 end,
+                                  phys_addr_t addr)
+{
+        int rc;
+        struct resource *tmp = NULL;
+        struct pci_mmcfg_region *cfg;
+
+        if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
+                return -ENODEV;
+
+        if (start > end)
+                return -EINVAL;
+
+        mutex_lock(&pci_mmcfg_lock);
+        cfg = pci_mmconfig_lookup(seg, start);
+        if (cfg) {
+                if (cfg->end_bus < end)
+                        dev_info(dev, FW_INFO
+                                 "MMCONFIG for "
+                                 "domain %04x [bus %02x-%02x] "
+                                 "only partially covers this bridge\n",
+                                  cfg->segment, cfg->start_bus, cfg->end_bus);
+                mutex_unlock(&pci_mmcfg_lock);
+                return -EEXIST;
+        }
+
+        if (!addr) {
+                mutex_unlock(&pci_mmcfg_lock);
+                return -EINVAL;
+        }
+
+        rc = -EBUSY;
+        cfg = pci_mmconfig_alloc(seg, start, end, addr);
+        if (cfg == NULL) {
+                dev_warn(dev, "fail to add MMCONFIG (out of memory)\n");
+                rc = -ENOMEM;
+        } else if (!pci_mmcfg_check_reserved(dev, cfg, 0)) {
+                dev_warn(dev, FW_BUG "MMCONFIG %pR isn't reserved\n",
+                         &cfg->res);
+        } else {
+                /* Insert resource if it's not in boot stage */
+                if (pci_mmcfg_running_state)
+                        tmp = insert_resource_conflict(&iomem_resource,
+                                                       &cfg->res);
+
+                if (tmp) {
+                        dev_warn(dev,
+                                 "MMCONFIG %pR conflicts with "
+                                 "%s %pR\n",
+                                 &cfg->res, tmp->name, tmp);
+                } else if (pci_mmcfg_arch_map(cfg)) {
+                        dev_warn(dev, "fail to map MMCONFIG %pR.\n",
+                                 &cfg->res);
+                } else {
+                        list_add_sorted(cfg);
+                        dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",
+                                 &cfg->res, (unsigned long)addr);
+                        cfg = NULL;
+                        rc = 0;
+                }
+        }
+
+        if (cfg) {
+                if (cfg->res.parent)
+                        release_resource(&cfg->res);
+                kfree(cfg);
+        }
+
+        mutex_unlock(&pci_mmcfg_lock);
+
+        return rc;
+}
+
+/* Delete MMCFG information for host bridges */
+int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
+{
+        struct pci_mmcfg_region *cfg;
+
+        mutex_lock(&pci_mmcfg_lock);
+        list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
+                if (cfg->segment == seg && cfg->start_bus == start &&
+                    cfg->end_bus == end) {
+                        list_del_rcu(&cfg->list);
+                        synchronize_rcu();
+                        pci_mmcfg_arch_unmap(cfg);
+                        if (cfg->res.parent)
+                                release_resource(&cfg->res);
+                        mutex_unlock(&pci_mmcfg_lock);
+                        kfree(cfg);
+                        return 0;
+                }
+        mutex_unlock(&pci_mmcfg_lock);
+
+        return -ENOENT;
+}