crypto: qat - Add load balancing across devices

Load balancing of crypto instances only used a single device.
There was no problem with that on PF, but since there is only
one or two instance per VF we need to loadbalance across devices.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/qat/qat_common/qat_crypto.c b/drivers/crypto/qat/qat_common/qat_crypto.c
index 07c2f9f..25db27c 100644 (file)
--- a/drivers/crypto/qat/qat_common/qat_crypto.c
+++ b/drivers/crypto/qat/qat_common/qat_crypto.c
@@ -60,8 +60,8 @@ static struct service_hndl qat_crypto;
 
 void qat_crypto_put_instance(struct qat_crypto_instance *inst)
 {
-       if (atomic_sub_return(1, &inst->refctr) == 0)
-               adf_dev_put(inst->accel_dev);
+       atomic_dec(&inst->refctr);
+       adf_dev_put(inst->accel_dev);
 }
 
 static int qat_crypto_free_instances(struct adf_accel_dev *accel_dev)
@@ -97,19 +97,26 @@ static int qat_crypto_free_instances(struct adf_accel_dev *accel_dev)
 struct qat_crypto_instance *qat_crypto_get_instance_node(int node)
 {
        struct adf_accel_dev *accel_dev = NULL;
-       struct qat_crypto_instance *inst_best = NULL;
+       struct qat_crypto_instance *inst = NULL;
        struct list_head *itr;
        unsigned long best = ~0;
 
        list_for_each(itr, adf_devmgr_get_head()) {
-               accel_dev = list_entry(itr, struct adf_accel_dev, list);
-
-               if ((node == dev_to_node(&GET_DEV(accel_dev)) ||
-                    dev_to_node(&GET_DEV(accel_dev)) < 0) &&
-                   adf_dev_started(accel_dev) &&
-                   !list_empty(&accel_dev->crypto_list))
-                       break;
-               accel_dev = NULL;
+               struct adf_accel_dev *tmp_dev;
+               unsigned long ctr;
+
+               tmp_dev = list_entry(itr, struct adf_accel_dev, list);
+
+               if ((node == dev_to_node(&GET_DEV(tmp_dev)) ||
+                    dev_to_node(&GET_DEV(tmp_dev)) < 0) &&
+                   adf_dev_started(tmp_dev) &&
+                   !list_empty(&tmp_dev->crypto_list)) {
+                       ctr = atomic_read(&tmp_dev->ref_count);
+                       if (best > ctr) {
+                               accel_dev = tmp_dev;
+                               best = ctr;
+                       }
+               }
        }
        if (!accel_dev) {
                pr_err("QAT: Could not find a device on node %d\n", node);
@@ -118,28 +125,26 @@ struct qat_crypto_instance *qat_crypto_get_instance_node(int node)
        if (!accel_dev || !adf_dev_started(accel_dev))
                return NULL;
 
+       best = ~0;
        list_for_each(itr, &accel_dev->crypto_list) {
-               struct qat_crypto_instance *inst;
-               unsigned long cur;
-
-               inst = list_entry(itr, struct qat_crypto_instance, list);
-               cur = atomic_read(&inst->refctr);
-               if (best > cur) {
-                       inst_best = inst;
-                       best = cur;
+               struct qat_crypto_instance *tmp_inst;
+               unsigned long ctr;
+
+               tmp_inst = list_entry(itr, struct qat_crypto_instance, list);
+               ctr = atomic_read(&tmp_inst->refctr);
+               if (best > ctr) {
+                       inst = tmp_inst;
+                       best = ctr;
                }
        }
-       if (inst_best) {
-               if (atomic_add_return(1, &inst_best->refctr) == 1) {
-                       if (adf_dev_get(accel_dev)) {
-                               atomic_dec(&inst_best->refctr);
-                               dev_err(&GET_DEV(accel_dev),
-                                       "Could not increment dev refctr\n");
-                               return NULL;
-                       }
+       if (inst) {
+               if (adf_dev_get(accel_dev)) {
+                       dev_err(&GET_DEV(accel_dev), "Could not increment dev refctr\n");
+                       return NULL;
                }
+               atomic_inc(&inst->refctr);
        }
-       return inst_best;
+       return inst;
 }
 
 static int qat_crypto_create_instances(struct adf_accel_dev *accel_dev)