iommu/amd: Add invalidate-context call-back

This call-back is invoked when the task that is bound to a
pasid is about to exit. The driver can use it to shutdown
all context related to that context in a safe way.

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

2 files changed, 52 insertions, 0 deletions

diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index fe812e2a0474..8add9f125d3e 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -63,6 +63,7 @@ struct device_state {
         int pasid_levels;
         int max_pasids;
         amd_iommu_invalid_ppr_cb inv_ppr_cb;
+        amd_iommu_invalidate_ctx inv_ctx_cb;
         spinlock_t lock;
         wait_queue_head_t wq;
 };
@@ -637,6 +638,9 @@ again:
                 dev_state = pasid_state->device_state;
                 pasid     = pasid_state->pasid;
 
+                if (pasid_state->device_state->inv_ctx_cb)
+                        dev_state->inv_ctx_cb(dev_state->pdev, pasid);
+
                 unbind_pasid(dev_state, pasid);
 
                 /* Task may be in the list multiple times */
@@ -881,6 +885,37 @@ out_unlock:
 }
 EXPORT_SYMBOL(amd_iommu_set_invalid_ppr_cb);
 
+int amd_iommu_set_invalidate_ctx_cb(struct pci_dev *pdev,
+                                    amd_iommu_invalidate_ctx cb)
+{
+        struct device_state *dev_state;
+        unsigned long flags;
+        u16 devid;
+        int ret;
+
+        if (!amd_iommu_v2_supported())
+                return -ENODEV;
+
+        devid = device_id(pdev);
+
+        spin_lock_irqsave(&state_lock, flags);
+
+        ret = -EINVAL;
+        dev_state = state_table[devid];
+        if (dev_state == NULL)
+                goto out_unlock;
+
+        dev_state->inv_ctx_cb = cb;
+
+        ret = 0;
+
+out_unlock:
+        spin_unlock_irqrestore(&state_lock, flags);
+
+        return ret;
+}
+EXPORT_SYMBOL(amd_iommu_set_invalidate_ctx_cb);
+
 static int __init amd_iommu_v2_init(void)
 {
         size_t state_table_size;
diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h
index c03c281ae6ee..ef00610837d4 100644
--- a/include/linux/amd-iommu.h
+++ b/include/linux/amd-iommu.h
@@ -145,6 +145,23 @@ struct amd_iommu_device_info {
 extern int amd_iommu_device_info(struct pci_dev *pdev,
                                  struct amd_iommu_device_info *info);
 
+/**
+ * amd_iommu_set_invalidate_ctx_cb() - Register a call-back for invalidating
+ *                                     a pasid context. This call-back is
+ *                                     invoked when the IOMMUv2 driver needs to
+ *                                     invalidate a PASID context, for example
+ *                                     because the task that is bound to that
+ *                                     context is about to exit.
+ *
+ * @pdev: The PCI device the call-back should be registered for
+ * @cb: The call-back function
+ */
+
+typedef void (*amd_iommu_invalidate_ctx)(struct pci_dev *pdev, int pasid);
+
+extern int amd_iommu_set_invalidate_ctx_cb(struct pci_dev *pdev,
+                                           amd_iommu_invalidate_ctx cb);
+
 #else
 
 static inline int amd_iommu_detect(void) { return -ENODEV; }