[PATCH] IB/mthca: Initialize eq->nent before we use it

In mthca_create_eq(), we call get_eqe() before setting eq->nent.  This
is wrong, because get_eqe() uses eq->nent.  Fix this, and clean up the
code a little while we're at it.  (We got lucky with the current code,
because eq->nent was cleared to 0, which get_eqe() made happen to do
the right thing)

Pointed out by Michael S. Tsirkin <mst@mellanox.co.il>

Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 5 insertions, 11 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_eq.c b/drivers/infiniband/hw/mthca/mthca_eq.c
index 18f0981eb0c1..78152a8ad17d 100644
--- a/drivers/infiniband/hw/mthca/mthca_eq.c
+++ b/drivers/infiniband/hw/mthca/mthca_eq.c
@@ -476,12 +476,8 @@ static int __devinit mthca_create_eq(struct mthca_dev *dev,
         int i;
         u8 status;
 
-        /* Make sure EQ size is aligned to a power of 2 size. */
-        for (i = 1; i < nent; i <<= 1)
-                ; /* nothing */
-        nent = i;
-
-        eq->dev = dev;
+        eq->dev  = dev;
+        eq->nent = roundup_pow_of_two(max(nent, 2));
 
         eq->page_list = kmalloc(npages * sizeof *eq->page_list,
                                 GFP_KERNEL);
@@ -512,7 +508,7 @@ static int __devinit mthca_create_eq(struct mthca_dev *dev,
                 memset(eq->page_list[i].buf, 0, PAGE_SIZE);
         }
 
-        for (i = 0; i < nent; ++i)
+        for (i = 0; i < eq->nent; ++i)
                 set_eqe_hw(get_eqe(eq, i));
 
         eq->eqn = mthca_alloc(&dev->eq_table.alloc);
@@ -528,8 +524,6 @@ static int __devinit mthca_create_eq(struct mthca_dev *dev,
         if (err)
                 goto err_out_free_eq;
 
-        eq->nent = nent;
-
         memset(eq_context, 0, sizeof *eq_context);
         eq_context->flags           = cpu_to_be32(MTHCA_EQ_STATUS_OK   |
                                                   MTHCA_EQ_OWNER_HW    |
@@ -538,7 +532,7 @@ static int __devinit mthca_create_eq(struct mthca_dev *dev,
         if (mthca_is_memfree(dev))
                 eq_context->flags  |= cpu_to_be32(MTHCA_EQ_STATE_ARBEL);
 
-        eq_context->logsize_usrpage = cpu_to_be32((ffs(nent) - 1) << 24);
+        eq_context->logsize_usrpage = cpu_to_be32((ffs(eq->nent) - 1) << 24);
         if (mthca_is_memfree(dev)) {
                 eq_context->arbel_pd = cpu_to_be32(dev->driver_pd.pd_num);
         } else {
@@ -569,7 +563,7 @@ static int __devinit mthca_create_eq(struct mthca_dev *dev,
         dev->eq_table.arm_mask |= eq->eqn_mask;
 
         mthca_dbg(dev, "Allocated EQ %d with %d entries\n",
-                  eq->eqn, nent);
+                  eq->eqn, eq->nent);
 
         return err;