x86/amd-iommu: Introduce global dev_data_list

This list keeps all allocated iommu_dev_data structs in a
list together. This is needed for instances that have no
associated device.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

2 files changed, 48 insertions, 9 deletions

diff --git a/arch/x86/include/asm/amd_iommu_types.h b/arch/x86/include/asm/amd_iommu_types.h
index 4c9982995414..35520e31c1b4 100644
--- a/arch/x86/include/asm/amd_iommu_types.h
+++ b/arch/x86/include/asm/amd_iommu_types.h
@@ -310,6 +310,7 @@ struct protection_domain {
  */
 struct iommu_dev_data {
         struct list_head list;            /* For domain->dev_list */
+        struct list_head dev_data_list;   /* For global dev_data_list */
         struct device *dev;               /* Device this data belong to */
         struct device *alias;             /* The Alias Device */
         struct protection_domain *domain; /* Domain the device is bound to */
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index cc6f6da630e8..8b8489084649 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -45,6 +45,10 @@ static DEFINE_RWLOCK(amd_iommu_devtable_lock);
 static LIST_HEAD(iommu_pd_list);
 static DEFINE_SPINLOCK(iommu_pd_list_lock);
 
+/* List of all available dev_data structures */
+static LIST_HEAD(dev_data_list);
+static DEFINE_SPINLOCK(dev_data_list_lock);
+
 /*
  * Domain for untranslated devices - only allocated
  * if iommu=pt passed on kernel cmd line.
@@ -68,6 +72,35 @@ static void update_domain(struct protection_domain *domain);
  *
  ****************************************************************************/
 
+static struct iommu_dev_data *alloc_dev_data(void)
+{
+        struct iommu_dev_data *dev_data;
+        unsigned long flags;
+
+        dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
+        if (!dev_data)
+                return NULL;
+
+        atomic_set(&dev_data->bind, 0);
+
+        spin_lock_irqsave(&dev_data_list_lock, flags);
+        list_add_tail(&dev_data->dev_data_list, &dev_data_list);
+        spin_unlock_irqrestore(&dev_data_list_lock, flags);
+
+        return dev_data;
+}
+
+static void free_dev_data(struct iommu_dev_data *dev_data)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev_data_list_lock, flags);
+        list_del(&dev_data->dev_data_list);
+        spin_unlock_irqrestore(&dev_data_list_lock, flags);
+
+        kfree(dev_data);
+}
+
 static inline u16 get_device_id(struct device *dev)
 {
         struct pci_dev *pdev = to_pci_dev(dev);
@@ -139,32 +172,28 @@ static int iommu_init_device(struct device *dev)
 {
         struct iommu_dev_data *dev_data;
         struct pci_dev *pdev;
-        u16 devid, alias;
+        u16 alias;
 
         if (dev->archdata.iommu)
                 return 0;
 
-        dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
+        dev_data = alloc_dev_data();
         if (!dev_data)
                 return -ENOMEM;
 
         dev_data->dev = dev;
 
-        devid = get_device_id(dev);
-        alias = amd_iommu_alias_table[devid];
+        alias = amd_iommu_alias_table[get_device_id(dev)];
         pdev = pci_get_bus_and_slot(PCI_BUS(alias), alias & 0xff);
         if (pdev)
                 dev_data->alias = &pdev->dev;
         else {
-                kfree(dev_data);
+                free_dev_data(dev_data);
                 return -ENOTSUPP;
         }
 
-        atomic_set(&dev_data->bind, 0);
-
         dev->archdata.iommu = dev_data;
 
-
         return 0;
 }
 
@@ -184,11 +213,16 @@ static void iommu_ignore_device(struct device *dev)
 
 static void iommu_uninit_device(struct device *dev)
 {
-        kfree(dev->archdata.iommu);
+        /*
+         * Nothing to do here - we keep dev_data around for unplugged devices
+         * and reuse it when the device is re-plugged - not doing so would
+         * introduce a ton of races.
+         */
 }
 
 void __init amd_iommu_uninit_devices(void)
 {
+        struct iommu_dev_data *dev_data, *n;
         struct pci_dev *pdev = NULL;
 
         for_each_pci_dev(pdev) {
@@ -198,6 +232,10 @@ void __init amd_iommu_uninit_devices(void)
 
                 iommu_uninit_device(&pdev->dev);
         }
+
+        /* Free all of our dev_data structures */
+        list_for_each_entry_safe(dev_data, n, &dev_data_list, dev_data_list)
+                free_dev_data(dev_data);
 }
 
 int __init amd_iommu_init_devices(void)