Re: [PATCH V2 6/6] PCI, ACPI, x86: update MMCFG information when hot-plugging PCI host bridges

[Jiang Liu <jiang.liu@huawei.com>]

On 2012-4-10 2:00, Yinghai Lu wrote:
> On Mon, Apr 9, 2012 at 9:22 AM, Jiang Liu<liuj97@gmail.com>  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@huawei.com>
>> ---
>>   arch/x86/pci/acpi.c      |   66 ++++++++++++++++++++++++++++++++++++++++++++++
>>   drivers/acpi/pci_root.c  |   20 ++++++++++++++
>>   include/acpi/acnames.h   |    1 +
>>   include/linux/pci-acpi.h |    2 +
>>   4 files changed, 89 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
>> index da0149d..e38d9b7 100644
>> --- a/arch/x86/pci/acpi.c
>> +++ b/arch/x86/pci/acpi.c
>> @@ -488,6 +488,72 @@ 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;
>> +
>> +       /* MMCONFIG disabled */
>> +       if ((pci_probe&  PCI_PROBE_MMCONF) == 0)
>> +               return 0;
>
> should be
>
> if (!!(pci_probe&  PCI_PROBE_MASK&  ~PCI_PROBE_MMCONF))
>         return 0;
OK, will change to use this.
I thought it's the same because it will clear all other PCI_PROBE_XXX
flags if MMCONF is enabled. But it's more reliable to make sure all
other PCI_PROBE_XXX flags are cleared.
---
pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
---
>
>> +
>> +       /*
>> +        * 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;
>> +
>> +       /* MMCONFIG disabled */
>> +       if ((pci_probe&  PCI_PROBE_MMCONF) == 0)
>> +               return 0;
>
> again should be
>
> if (!!(pci_probe&  PCI_PROBE_MASK&  ~PCI_PROBE_MMCONF))
>         return 0;
>
>
>
>> +
>> +       /* Remove 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))
>> +               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..6e8dd10 100644
>> --- a/include/linux/pci-acpi.h
>> +++ b/include/linux/pci-acpi.h
>> @@ -37,6 +37,8 @@ static inline acpi_handle acpi_pci_get_bridge_handle(struct pci_bus *pbus)
>>   }
>>
>>   void acpi_pci_root_rescan(void);
>> +int arch_acpi_pci_root_add(struct acpi_pci_root *root);
>> +int arch_acpi_pci_root_remove(struct acpi_pci_root *root);
>>
>>   #else
>>
>> --
>> 1.7.5.4
>>
>
> .
>