Re: [PATCH 2/2] PCI, ACPI, x86: update MMCFG information when hot-plugging PCI host bridges

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Hi Yinghai,
	Thanks for your comments and will send out another version
according to your suggestions.
On 2012-4-9 3:19, Yinghai Lu wrote:
On Sun, Apr 8, 2012 at 10:12 AM, Jiang Liu<liuj97@xxxxxxxxx>  wrote:
This patch enhances pci_root driver to update MMCFG information when
hot-plugging PCI root bridges on x86 platforms.

Signed-off-by: Jiang Liu<jiang.liu@xxxxxxxxxx>
---
  arch/x86/pci/acpi.c      |   58 ++++++++++++++++++++++++++++++++++++++++++++++
  drivers/acpi/pci_root.c  |   20 ++++++++++++++++
  include/acpi/acnames.h   |    1 +
  include/linux/pci-acpi.h |    3 ++
  4 files changed, 82 insertions(+), 0 deletions(-)

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index da0149d..9184970 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -488,6 +488,64 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
        return bus;
  }

+int arch_acpi_pci_root_add(struct acpi_pci_root *root)
+{
+       int result = 0;
+       acpi_status status;
+       unsigned long long base_addr;
+       struct pci_mmcfg_region *cfg;
+
+       /*
+        * Try to insert MMCFG information for host bridges with _CBA method
+        */
+       status = acpi_evaluate_integer(root->device->handle, METHOD_NAME__CBA,
+                                      NULL,&base_addr);
+       if (ACPI_SUCCESS(status)) {
+               result = pci_mmconfig_insert(root->segment,
+                                            root->secondary.start,
+                                            root->secondary.end,
+                                            base_addr);
+               /*
+                * MMCFG information for hot-pluggable host bridges may have
+                * already been added by __pci_mmcfg_init();
+                */
+               if (result == -EEXIST)
+                       result = 0;
+       } else if (status == AE_NOT_FOUND) {
+               /*
+                * Check whether MMCFG information has been added for
+                * host bridges without _CBA method.
+                */
+               rcu_read_lock();
+               cfg = pci_mmconfig_lookup(root->segment, root->secondary.start);
+               if (!cfg || cfg->end_bus<  root->secondary.end)
+                       result = -ENODEV;
+               rcu_read_unlock();
+       } else
+               result = -ENODEV;
+
+       return result;
+}
+
+int arch_acpi_pci_root_remove(struct acpi_pci_root *root)
+{
+       acpi_status status;
+       unsigned long long base_addr;
+
+       /* Remove MMCFG information for host bridges with _CBA method */
+       status = acpi_evaluate_integer(root->device->handle, METHOD_NAME__CBA,
+                                      NULL,&base_addr);

add one flag in acpi_pci_root about we added mmconf for it before?
like mmconf_added?

+       if (ACPI_SUCCESS(status))
+               return pci_mmconfig_delete(root->segment,
+                                          root->secondary.start,
+                                          root->secondary.end,
+                                          base_addr);
+       else if (status != AE_NOT_FOUND)
+               return -ENODEV;
+
+       return 0;
+}
+
  int __init pci_acpi_init(void)
  {
        struct pci_dev *dev = NULL;
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 4a7d575..a62bfa8 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -448,6 +448,16 @@ out:
  }
  EXPORT_SYMBOL(acpi_pci_osc_control_set);

+int __weak arch_acpi_pci_root_add(struct acpi_pci_root *root)
+{
+       return 0;
+}
+
+int __weak arch_acpi_pci_root_remove(struct acpi_pci_root *root)
+{
+       return 0;
+}
+
  static int __devinit acpi_pci_root_add(struct acpi_device *device)
  {
        unsigned long long segment, bus;
@@ -504,6 +514,14 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
        strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
        device->driver_data = root;

+       if (arch_acpi_pci_root_add(root)) {
+               printk(KERN_ERR PREFIX
+                       "can't add MMCFG information for Bus %04x:%02x\n",
+                       root->segment, (unsigned int)root->secondary.start);
+               result = -ENODEV;
+               goto out_free;
+       }
+
        /*
         * All supported architectures that use ACPI have support for
         * PCI domains, so we indicate this in _OSC support capabilities.
@@ -629,6 +647,7 @@ out_del_root:
        list_del_rcu(&root->node);
        mutex_unlock(&acpi_pci_root_lock);
        synchronize_rcu();
+       arch_acpi_pci_root_remove(root);
  out_free:
        kfree(root);
        return result;
@@ -679,6 +698,7 @@ out:
        list_del_rcu(&root->node);
        mutex_unlock(&acpi_pci_root_lock);
        synchronize_rcu();
+       arch_acpi_pci_root_remove(root);
        kfree(root);

        return 0;
diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
index 38f5088..99bda75 100644
--- a/include/acpi/acnames.h
+++ b/include/acpi/acnames.h
@@ -62,6 +62,7 @@
  #define METHOD_NAME__AEI        "_AEI"
  #define METHOD_NAME__PRW        "_PRW"
  #define METHOD_NAME__SRS        "_SRS"
+#define METHOD_NAME__CBA       "_CBA"

  /* Method names - these methods must appear at the namespace root */

diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index ac93634..816b971 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -38,6 +38,9 @@ static inline acpi_handle acpi_pci_get_bridge_handle(struct pci_bus *pbus)

  void acpi_pci_root_rescan(void);

+extern int arch_acpi_pci_root_add(struct acpi_pci_root *root);
+extern int arch_acpi_pci_root_remove(struct acpi_pci_root *root);
+

don't need extern here.

  #else

  static inline void acpi_pci_root_rescan(void) { }
--
1.7.5.4


.



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