x86/PCI: introduce pci_mmcfg_arch_map()/pci_mmcfg_arch_unmap()

Introduce pci_mmcfg_arch_map()/pci_mmcfg_arch_unmap(), which will be used
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>

3 files changed, 43 insertions, 12 deletions

diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index b3a531746026..df898ceab4d4 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -135,6 +135,8 @@ struct pci_mmcfg_region {
 
 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 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_32.c b/arch/x86/pci/mmconfig_32.c
index 5dad04aa6b37..a22785deb50e 100644
--- a/arch/x86/pci/mmconfig_32.c
+++ b/arch/x86/pci/mmconfig_32.c
@@ -141,3 +141,18 @@ int __init pci_mmcfg_arch_init(void)
 void __init pci_mmcfg_arch_free(void)
 {
 }
+
+int __devinit pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg)
+{
+        return 0;
+}
+
+void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg)
+{
+        unsigned long flags;
+
+        /* Invalidate the cached mmcfg map entry. */
+        raw_spin_lock_irqsave(&pci_config_lock, flags);
+        mmcfg_last_accessed_device = 0;
+        raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+}
diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index acc48c5b6863..ebefea5107a7 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -95,7 +95,7 @@ static const struct pci_raw_ops pci_mmcfg = {
         .write =        pci_mmcfg_write,
 };
 
-static void __iomem * __init mcfg_ioremap(struct pci_mmcfg_region *cfg)
+static void __iomem * __devinit mcfg_ioremap(struct pci_mmcfg_region *cfg)
 {
         void __iomem *addr;
         u64 start, size;
@@ -114,16 +114,14 @@ int __init pci_mmcfg_arch_init(void)
 {
         struct pci_mmcfg_region *cfg;
 
-        list_for_each_entry(cfg, &pci_mmcfg_list, list) {
-                cfg->virt = mcfg_ioremap(cfg);
-                if (!cfg->virt) {
-                        printk(KERN_ERR PREFIX "can't map MMCONFIG at %pR\n",
-                               &cfg->res);
+        list_for_each_entry(cfg, &pci_mmcfg_list, list)
+                if (pci_mmcfg_arch_map(cfg)) {
                         pci_mmcfg_arch_free();
                         return 0;
                 }
-        }
+
         raw_pci_ext_ops = &pci_mmcfg;
+
         return 1;
 }
 
@@ -131,10 +129,26 @@ void __init pci_mmcfg_arch_free(void)
 {
         struct pci_mmcfg_region *cfg;
 
-        list_for_each_entry(cfg, &pci_mmcfg_list, list) {
-                if (cfg->virt) {
-                        iounmap(cfg->virt + PCI_MMCFG_BUS_OFFSET(cfg->start_bus));
-                        cfg->virt = NULL;
-                }
+        list_for_each_entry(cfg, &pci_mmcfg_list, list)
+                pci_mmcfg_arch_unmap(cfg);
+}
+
+int __devinit pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg)
+{
+        cfg->virt = mcfg_ioremap(cfg);
+        if (!cfg->virt) {
+                printk(KERN_ERR PREFIX "can't map MMCONFIG at %pR\n",
+                       &cfg->res);
+                return -ENOMEM;
+        }
+
+        return 0;
+}
+
+void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg)
+{
+        if (cfg && cfg->virt) {
+                iounmap(cfg->virt + PCI_MMCFG_BUS_OFFSET(cfg->start_bus));
+                cfg->virt = NULL;
         }
 }