[openib-general] Re: [PATCH] dont create physical mr for user context

[Roland Dreier]

Thanks, excellent catch.  I changed your patch slightly as below to
make "privileged" a parameter to mthca_pd_alloc() so that it's harder
for someone to leave it uninitialized by accident.

 - R.

--- infiniband/hw/mthca/mthca_dev.h	(revision 2468)
+++ infiniband/hw/mthca/mthca_dev.h	(working copy)
@@ -384,7 +384,7 @@ void mthca_unregister_device(struct mthc
 int mthca_uar_alloc(struct mthca_dev *dev, struct mthca_uar *uar);
 void mthca_uar_free(struct mthca_dev *dev, struct mthca_uar *uar);
 
-int mthca_pd_alloc(struct mthca_dev *dev, struct mthca_pd *pd);
+int mthca_pd_alloc(struct mthca_dev *dev, int privileged, struct mthca_pd *pd);
 void mthca_pd_free(struct mthca_dev *dev, struct mthca_pd *pd);
 
 int mthca_mr_alloc_notrans(struct mthca_dev *dev, u32 pd,
--- infiniband/hw/mthca/mthca_main.c	(revision 2468)
+++ infiniband/hw/mthca/mthca_main.c	(working copy)
@@ -664,7 +664,7 @@ static int __devinit mthca_setup_hca(str
 		goto err_pd_table_free;
 	}
 
-	err = mthca_pd_alloc(dev, &dev->driver_pd);
+	err = mthca_pd_alloc(dev, 1, &dev->driver_pd);
 	if (err) {
 		mthca_err(dev, "Failed to create driver PD, "
 			  "aborting.\n");
--- infiniband/hw/mthca/mthca_provider.c	(revision 2468)
+++ infiniband/hw/mthca/mthca_provider.c	(working copy)
@@ -379,7 +379,7 @@ static struct ib_pd *mthca_alloc_pd(stru
 	if (!pd)
 		return ERR_PTR(-ENOMEM);
 
-	err = mthca_pd_alloc(to_mdev(ibdev), pd);
+	err = mthca_pd_alloc(to_mdev(ibdev), !context, pd);
 	if (err) {
 		kfree(pd);
 		return ERR_PTR(err);
--- infiniband/hw/mthca/mthca_provider.h	(revision 2468)
+++ infiniband/hw/mthca/mthca_provider.h	(working copy)
@@ -91,6 +91,7 @@ struct mthca_pd {
 	u32             pd_num;
 	atomic_t        sqp_count;
 	struct mthca_mr ntmr;
+	int             privileged;
 };
 
 struct mthca_eq {
--- infiniband/hw/mthca/mthca_pd.c	(revision 2468)
+++ infiniband/hw/mthca/mthca_pd.c	(working copy)
@@ -37,23 +37,27 @@
 
 #include "mthca_dev.h"
 
-int mthca_pd_alloc(struct mthca_dev *dev, struct mthca_pd *pd)
+int mthca_pd_alloc(struct mthca_dev *dev, int privileged, struct mthca_pd *pd)
 {
-	int err;
+	int err = 0;
 
 	might_sleep();
 
+	pd->privileged = privileged;
+
 	atomic_set(&pd->sqp_count, 0);
 	pd->pd_num = mthca_alloc(&dev->pd_table.alloc);
 	if (pd->pd_num == -1)
 		return -ENOMEM;
 
-	err = mthca_mr_alloc_notrans(dev, pd->pd_num,
-				     MTHCA_MPT_FLAG_LOCAL_READ |
-				     MTHCA_MPT_FLAG_LOCAL_WRITE,
-				     &pd->ntmr);
-	if (err)
-		mthca_free(&dev->pd_table.alloc, pd->pd_num);
+	if (privileged) {
+		err = mthca_mr_alloc_notrans(dev, pd->pd_num,
+					     MTHCA_MPT_FLAG_LOCAL_READ |
+					     MTHCA_MPT_FLAG_LOCAL_WRITE,
+					     &pd->ntmr);
+		if (err)
+			mthca_free(&dev->pd_table.alloc, pd->pd_num);
+	}
 
 	return err;
 }
@@ -61,7 +65,8 @@ int mthca_pd_alloc(struct mthca_dev *dev
 void mthca_pd_free(struct mthca_dev *dev, struct mthca_pd *pd)
 {
 	might_sleep();
-	mthca_free_mr(dev, &pd->ntmr);
+	if (pd->privileged)
+		mthca_free_mr(dev, &pd->ntmr);
 	mthca_free(&dev->pd_table.alloc, pd->pd_num);
 }