crypto: qat - change behaviour of adf_cfg_add_key_value_param()

The function adf_cfg_add_key_value_param() allows to insert duplicates
entries in the key value store of the driver.

Change the behaviour of that function to the following policy:
- if the key doesn't exist, add it;
- if the key already exists with a different value, then delete it and
  replace it with a new one containing the new value;
- if the key exists with the same value, then return without doing
  anything.

The behaviour of this function has been changed in order to easily
update key-values in the driver database. In particular this is required
to update the value of the ServiceEnables key used to change the service
loaded on a device.

Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Adam Guerin <adam.guerin@intel.com>
Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
Reviewed-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Reviewed-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/qat/qat_common/adf_cfg.c b/drivers/crypto/qat/qat_common/adf_cfg.c
index b5b208cbe5a1200e0638c8fb0d6454d80bd1e3bd..e61b3e13db3bdcd071365bc63439ac9e9d409aa3 100644 (file)
--- a/drivers/crypto/qat/qat_common/adf_cfg.c
+++ b/drivers/crypto/qat/qat_common/adf_cfg.c
@@ -128,6 +128,24 @@ static void adf_cfg_keyval_add(struct adf_cfg_key_val *new,
        list_add_tail(&new->list, &sec->param_head);
 }
 
+static void adf_cfg_keyval_remove(const char *key, struct adf_cfg_section *sec)
+{
+       struct list_head *head = &sec->param_head;
+       struct list_head *list_ptr, *tmp;
+
+       list_for_each_prev_safe(list_ptr, tmp, head) {
+               struct adf_cfg_key_val *ptr =
+                       list_entry(list_ptr, struct adf_cfg_key_val, list);
+
+               if (strncmp(ptr->key, key, sizeof(ptr->key)))
+                       continue;
+
+               list_del(list_ptr);
+               kfree(ptr);
+               break;
+       }
+}
+
 static void adf_cfg_keyval_del_all(struct list_head *head)
 {
        struct list_head *list_ptr, *tmp;
@@ -208,7 +226,8 @@ static int adf_cfg_key_val_get(struct adf_accel_dev *accel_dev,
  * @type: Type - string, int or address
  *
  * Function adds configuration key - value entry in the appropriate section
- * in the given acceleration device
+ * in the given acceleration device. If the key exists already, the value
+ * is updated.
  * To be used by QAT device specific drivers.
  *
  * Return: 0 on success, error code otherwise.
@@ -222,6 +241,8 @@ int adf_cfg_add_key_value_param(struct adf_accel_dev *accel_dev,
        struct adf_cfg_key_val *key_val;
        struct adf_cfg_section *section = adf_cfg_sec_find(accel_dev,
                                                           section_name);
+       char temp_val[ADF_CFG_MAX_VAL_LEN_IN_BYTES];
+
        if (!section)
                return -EFAULT;
 
@@ -246,6 +267,24 @@ int adf_cfg_add_key_value_param(struct adf_accel_dev *accel_dev,
                return -EINVAL;
        }
        key_val->type = type;
+
+       /* Add the key-value pair as below policy:
+        * 1. if the key doesn't exist, add it;
+        * 2. if the key already exists with a different value then update it
+        *    to the new value (the key is deleted and the newly created
+        *    key_val containing the new value is added to the database);
+        * 3. if the key exists with the same value, then return without doing
+        *    anything (the newly created key_val is freed).
+        */
+       if (!adf_cfg_key_val_get(accel_dev, section_name, key, temp_val)) {
+               if (strncmp(temp_val, key_val->val, sizeof(temp_val))) {
+                       adf_cfg_keyval_remove(key, section);
+               } else {
+                       kfree(key_val);
+                       return 0;
+               }
+       }
+
        down_write(&cfg->lock);
        adf_cfg_keyval_add(key_val, section);
        up_write(&cfg->lock);