cxgb3 - Safeguard TCAM size usage

Ensure that the TCAM active region size is at least 16.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

3 files changed, 11 insertions, 3 deletions

diff --git a/drivers/net/cxgb3/common.h b/drivers/net/cxgb3/common.h
index 85e5543cfb57..38a0565ad1c1 100644
--- a/drivers/net/cxgb3/common.h
+++ b/drivers/net/cxgb3/common.h
@@ -358,6 +358,9 @@ enum {
         MC5_MODE_72_BIT = 2
 };
 
+/* MC5 min active region size */
+enum { MC5_MIN_TIDS = 16 };
+
 struct vpd_params {
         unsigned int cclk;
         unsigned int mclk;
diff --git a/drivers/net/cxgb3/cxgb3_main.c b/drivers/net/cxgb3/cxgb3_main.c
index d55383610559..b82544e08689 100644
--- a/drivers/net/cxgb3/cxgb3_main.c
+++ b/drivers/net/cxgb3/cxgb3_main.c
@@ -485,12 +485,14 @@ static ssize_t show_##name(struct device *d, struct device_attribute *attr, \
 static ssize_t set_nfilters(struct net_device *dev, unsigned int val)
 {
         struct adapter *adap = dev->priv;
+        int min_tids = is_offload(adap) ? MC5_MIN_TIDS : 0;
 
         if (adap->flags & FULL_INIT_DONE)
                 return -EBUSY;
         if (val && adap->params.rev == 0)
                 return -EINVAL;
-        if (val > t3_mc5_size(&adap->mc5) - adap->params.mc5.nservers)
+        if (val > t3_mc5_size(&adap->mc5) - adap->params.mc5.nservers -
+            min_tids)
                 return -EINVAL;
         adap->params.mc5.nfilters = val;
         return 0;
@@ -508,7 +510,8 @@ static ssize_t set_nservers(struct net_device *dev, unsigned int val)
 
         if (adap->flags & FULL_INIT_DONE)
                 return -EBUSY;
-        if (val > t3_mc5_size(&adap->mc5) - adap->params.mc5.nfilters)
+        if (val > t3_mc5_size(&adap->mc5) - adap->params.mc5.nfilters -
+            MC5_MIN_TIDS)
                 return -EINVAL;
         adap->params.mc5.nservers = val;
         return 0;
diff --git a/drivers/net/cxgb3/cxgb3_offload.c b/drivers/net/cxgb3/cxgb3_offload.c
index f6ed033efb56..eed7a48e3111 100644
--- a/drivers/net/cxgb3/cxgb3_offload.c
+++ b/drivers/net/cxgb3/cxgb3_offload.c
@@ -553,7 +553,9 @@ int cxgb3_alloc_atid(struct t3cdev *tdev, struct cxgb3_client *client,
         struct tid_info *t = &(T3C_DATA(tdev))->tid_maps;
 
         spin_lock_bh(&t->atid_lock);
-        if (t->afree) {
+        if (t->afree &&
+            t->atids_in_use + atomic_read(&t->tids_in_use) + MC5_MIN_TIDS <=
+            t->ntids) {
                 union active_open_entry *p = t->afree;
 
                 atid = (p - t->atid_tab) + t->atid_base;