IB/mthca: multiple fixes for multicast group handling

Multicast group management fixes:
. Fix leak of mailbox memory in error handling on multicast group operations.
. Free AMGM indices at detach and in attach error handling.
. Fix amount to shift for aligning next_gid_index in mailbox: it
  starts at bit 6, not bit 5.
. Allocate AMGM index after end of MGM table, in the range num_mgms to
  multicast table size - 1. Add some BUG_ON checks to catch cases
  where the index falls in the MGM hash area.
. Initialize the list of QPs in a newly-allocated group from AMGM to 0
  This is necessary since when a group is moved from AMGM to MGM (in the
  case where the MGM entry has been emptied of QPs), the AMGM entry is
  not reset to 0 (and we don't want an extra command to do that).

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 35 insertions, 19 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_mcg.c b/drivers/infiniband/hw/mthca/mthca_mcg.c
index 2fc449da418d..77bc6c746f43 100644
--- a/drivers/infiniband/hw/mthca/mthca_mcg.c
+++ b/drivers/infiniband/hw/mthca/mthca_mcg.c
@@ -111,7 +111,8 @@ static int find_mgm(struct mthca_dev *dev,
                         goto out;
                 if (status) {
                         mthca_err(dev, "READ_MGM returned status %02x\n", status);
-                        return -EINVAL;
+                        err = -EINVAL;
+                        goto out;
                 }
 
                 if (!memcmp(mgm->gid, zero_gid, 16)) {
@@ -126,7 +127,7 @@ static int find_mgm(struct mthca_dev *dev,
                         goto out;
 
                 *prev = *index;
-                *index = be32_to_cpu(mgm->next_gid_index) >> 5;
+                *index = be32_to_cpu(mgm->next_gid_index) >> 6;
         } while (*index);
 
         *index = -1;
@@ -153,8 +154,10 @@ int mthca_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
                 return PTR_ERR(mailbox);
         mgm = mailbox->buf;
 
-        if (down_interruptible(&dev->mcg_table.sem))
-                return -EINTR;
+        if (down_interruptible(&dev->mcg_table.sem)) {
+                err = -EINTR;
+                goto err_sem;
+        }
 
         err = find_mgm(dev, gid->raw, mailbox, &hash, &prev, &index);
         if (err)
@@ -181,9 +184,8 @@ int mthca_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
                         err = -EINVAL;
                         goto out;
                 }
-
+                memset(mgm, 0, sizeof *mgm);
                 memcpy(mgm->gid, gid->raw, 16);
-                mgm->next_gid_index = 0;
         }
 
         for (i = 0; i < MTHCA_QP_PER_MGM; ++i)
@@ -209,6 +211,7 @@ int mthca_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
         if (status) {
                 mthca_err(dev, "WRITE_MGM returned status %02x\n", status);
                 err = -EINVAL;
+                goto out;
         }
 
         if (!link)
@@ -223,7 +226,7 @@ int mthca_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
                 goto out;
         }
 
-        mgm->next_gid_index = cpu_to_be32(index << 5);
+        mgm->next_gid_index = cpu_to_be32(index << 6);
 
         err = mthca_WRITE_MGM(dev, prev, mailbox, &status);
         if (err)
@@ -234,7 +237,12 @@ int mthca_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
         }
 
  out:
+        if (err && link && index != -1) {
+                BUG_ON(index < dev->limits.num_mgms);
+                mthca_free(&dev->mcg_table.alloc, index);
+        }
         up(&dev->mcg_table.sem);
+ err_sem:
         mthca_free_mailbox(dev, mailbox);
         return err;
 }
@@ -255,8 +263,10 @@ int mthca_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
                 return PTR_ERR(mailbox);
         mgm = mailbox->buf;
 
-        if (down_interruptible(&dev->mcg_table.sem))
-                return -EINTR;
+        if (down_interruptible(&dev->mcg_table.sem)) {
+                err = -EINTR;
+                goto err_sem;
+        }
 
         err = find_mgm(dev, gid->raw, mailbox, &hash, &prev, &index);
         if (err)
@@ -305,13 +315,11 @@ int mthca_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
         if (i != 1)
                 goto out;
 
-        goto out;
-
         if (prev == -1) {
                 /* Remove entry from MGM */
-                if (be32_to_cpu(mgm->next_gid_index) >> 5) {
-                        err = mthca_READ_MGM(dev,
-                                             be32_to_cpu(mgm->next_gid_index) >> 5,
+                int amgm_index_to_free = be32_to_cpu(mgm->next_gid_index) >> 6;
+                if (amgm_index_to_free) {
+                        err = mthca_READ_MGM(dev, amgm_index_to_free,
                                              mailbox, &status);
                         if (err)
                                 goto out;
@@ -332,9 +340,13 @@ int mthca_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
                         err = -EINVAL;
                         goto out;
                 }
+                if (amgm_index_to_free) {
+                        BUG_ON(amgm_index_to_free < dev->limits.num_mgms);
+                        mthca_free(&dev->mcg_table.alloc, amgm_index_to_free);
+                }
         } else {
                 /* Remove entry from AMGM */
-                index = be32_to_cpu(mgm->next_gid_index) >> 5;
+                int curr_next_index = be32_to_cpu(mgm->next_gid_index) >> 6;
                 err = mthca_READ_MGM(dev, prev, mailbox, &status);
                 if (err)
                         goto out;
@@ -344,7 +356,7 @@ int mthca_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
                         goto out;
                 }
 
-                mgm->next_gid_index = cpu_to_be32(index << 5);
+                mgm->next_gid_index = cpu_to_be32(curr_next_index << 6);
 
                 err = mthca_WRITE_MGM(dev, prev, mailbox, &status);
                 if (err)
@@ -354,10 +366,13 @@ int mthca_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
                         err = -EINVAL;
                         goto out;
                 }
+                BUG_ON(index < dev->limits.num_mgms);
+                mthca_free(&dev->mcg_table.alloc, index);
         }
 
  out:
         up(&dev->mcg_table.sem);
+ err_sem:
         mthca_free_mailbox(dev, mailbox);
         return err;
 }
@@ -365,11 +380,12 @@ int mthca_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
 int __devinit mthca_init_mcg_table(struct mthca_dev *dev)
 {
         int err;
+        int table_size = dev->limits.num_mgms + dev->limits.num_amgms;
 
         err = mthca_alloc_init(&dev->mcg_table.alloc,
-                               dev->limits.num_amgms,
-                               dev->limits.num_amgms - 1,
-                               0);
+                               table_size,
+                               table_size - 1,
+                               dev->limits.num_mgms);
         if (err)
                 return err;