iwlwifi: add testmode command for rx forwarding

Added a testmode command which tells iwl_rx_dispatch
to send the RX both as a notification to nl80211 and
with the registered RX handlers.

This is used for monitoring RX from userspace while preserving
the regular flows in the driver.

Signed-off-by: Amit Beka <amit.beka@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 56 insertions, 9 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rx.c b/drivers/net/wireless/iwlwifi/iwl-agn-rx.c
index e504675f2637..8e7cdfaf10cc 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rx.c
@@ -1152,6 +1152,8 @@ int iwl_rx_dispatch(struct iwl_op_mode *op_mode, struct iwl_rx_cmd_buffer *rxb,
 {
         struct iwl_rx_packet *pkt = rxb_addr(rxb);
         struct iwl_priv *priv = IWL_OP_MODE_GET_DVM(op_mode);
+        void (*pre_rx_handler)(struct iwl_priv *,
+                               struct iwl_rx_cmd_buffer *);
         int err = 0;
 
         /*
@@ -1161,10 +1163,20 @@ int iwl_rx_dispatch(struct iwl_op_mode *op_mode, struct iwl_rx_cmd_buffer *rxb,
          */
         iwl_notification_wait_notify(&priv->notif_wait, pkt);
 
-        if (priv->pre_rx_handler &&
-            priv->ucode_owner == IWL_OWNERSHIP_TM)
-                priv->pre_rx_handler(priv, rxb);
-        else {
+        /* RX data may be forwarded to userspace (using pre_rx_handler) in one
+         * of two cases: the first, that the user owns the uCode through
+         * testmode - in such case the pre_rx_handler is set and no further
+         * processing takes place. The other case is when the user want to
+         * monitor the rx w/o affecting the regular flow - the pre_rx_handler
+         * will be set but the ownership flag != IWL_OWNERSHIP_TM and the flow
+         * continues.
+         * We need to use ACCESS_ONCE to prevent a case where the handler
+         * changes between the check and the call.
+         */
+        pre_rx_handler = ACCESS_ONCE(priv->pre_rx_handler);
+        if (pre_rx_handler)
+                pre_rx_handler(priv, rxb);
+        if (priv->ucode_owner != IWL_OWNERSHIP_TM) {
                 /* Based on type of command response or notification,
                  *   handle those that need handling via function in
                  *   rx_handlers table.  See iwl_setup_rx_handlers() */
diff --git a/drivers/net/wireless/iwlwifi/iwl-testmode.c b/drivers/net/wireless/iwlwifi/iwl-testmode.c
index 1d732092ebe7..b8044bcd5044 100644
--- a/drivers/net/wireless/iwlwifi/iwl-testmode.c
+++ b/drivers/net/wireless/iwlwifi/iwl-testmode.c
@@ -125,6 +125,8 @@ struct nla_policy iwl_testmode_gnl_msg_policy[IWL_TM_ATTR_MAX] = {
         [IWL_TM_ATTR_FW_TYPE] = { .type = NLA_U32, },
         [IWL_TM_ATTR_FW_INST_SIZE] = { .type = NLA_U32, },
         [IWL_TM_ATTR_FW_DATA_SIZE] = { .type = NLA_U32, },
+
+        [IWL_TM_ATTR_ENABLE_NOTIFICATION] = {.type = NLA_FLAG, },
 };
 
 /*
@@ -194,7 +196,7 @@ nla_put_failure:
 
 void iwl_testmode_init(struct iwl_priv *priv)
 {
-        priv->pre_rx_handler = iwl_testmode_ucode_rx_pkt;
+        priv->pre_rx_handler = NULL;
         priv->testmode_trace.trace_enabled = false;
         priv->testmode_mem.read_in_progress = false;
 }
@@ -770,9 +772,13 @@ static int iwl_testmode_ownership(struct ieee80211_hw *hw, struct nlattr **tb)
         }
 
         owner = nla_get_u8(tb[IWL_TM_ATTR_UCODE_OWNER]);
-        if ((owner == IWL_OWNERSHIP_DRIVER) || (owner == IWL_OWNERSHIP_TM))
+        if (owner == IWL_OWNERSHIP_DRIVER) {
                 priv->ucode_owner = owner;
-        else {
+                priv->pre_rx_handler = NULL;
+        } else if (owner == IWL_OWNERSHIP_TM) {
+                priv->pre_rx_handler = iwl_testmode_ucode_rx_pkt;
+                priv->ucode_owner = owner;
+        } else {
                 IWL_ERR(priv, "Invalid owner\n");
                 return -EINVAL;
         }
@@ -937,6 +943,20 @@ static int iwl_testmode_buffer_dump(struct ieee80211_hw *hw,
         return -ENOBUFS;
 }
 
+static int iwl_testmode_notifications(struct ieee80211_hw *hw,
+        struct nlattr **tb)
+{
+        struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
+        bool enable;
+
+        enable = nla_get_flag(tb[IWL_TM_ATTR_ENABLE_NOTIFICATION]);
+        if (enable)
+                priv->pre_rx_handler = iwl_testmode_ucode_rx_pkt;
+        else
+                priv->pre_rx_handler = NULL;
+        return 0;
+}
+
 
 /* The testmode gnl message handler that takes the gnl message from the
  * user space and parses it per the policy iwl_testmode_gnl_msg_policy, then
@@ -1022,6 +1042,12 @@ int iwlagn_mac_testmode_cmd(struct ieee80211_hw *hw, void *data, int len)
                 result = iwl_testmode_indirect_mem(hw, tb);
                 break;
 
+        case IWL_TM_CMD_APP2DEV_NOTIFICATIONS:
+                IWL_DEBUG_INFO(priv, "testmode notifications cmd "
+                        "to driver\n");
+                result = iwl_testmode_notifications(hw, tb);
+                break;
+
         default:
                 IWL_ERR(priv, "Unknown testmode command\n");
                 result = -ENOSYS;
diff --git a/drivers/net/wireless/iwlwifi/iwl-testmode.h b/drivers/net/wireless/iwlwifi/iwl-testmode.h
index 69b2e80f4071..6ba211b09426 100644
--- a/drivers/net/wireless/iwlwifi/iwl-testmode.h
+++ b/drivers/net/wireless/iwlwifi/iwl-testmode.h
@@ -122,6 +122,9 @@
  *      Fore reading, a READ command is sent from the userspace and the data
  *      is returned when the user calls a DUMP command.
  *      For writing, only a WRITE command is used.
+ * @IWL_TM_CMD_APP2DEV_NOTIFICATIONS:
+ *      Command to enable/disable notifications (currently RX packets) from the
+ *      driver to userspace.
  */
 enum iwl_tm_cmd_t {
         IWL_TM_CMD_APP2DEV_UCODE                = 1,
@@ -152,7 +155,8 @@ enum iwl_tm_cmd_t {
         IWL_TM_CMD_APP2DEV_INDIRECT_BUFFER_READ = 26,
         IWL_TM_CMD_APP2DEV_INDIRECT_BUFFER_DUMP = 27,
         IWL_TM_CMD_APP2DEV_INDIRECT_BUFFER_WRITE = 28,
-        IWL_TM_CMD_MAX                          = 29,
+        IWL_TM_CMD_APP2DEV_NOTIFICATIONS        = 29,
+        IWL_TM_CMD_MAX                          = 30,
 };
 
 /*
@@ -256,6 +260,10 @@ enum iwl_tm_cmd_t {
  *      When IWL_TM_ATTR_COMMAND is IWL_TM_CMD_APP2DEV_UCODE this flag
  *      indicates that the user wants to receive the response of the command
  *      in a reply SKB. If it's not present, the response is not returned.
+ * @IWL_TM_ATTR_ENABLE_NOTIFICATIONS:
+ *      When IWL_TM_ATTR_COMMAND is IWL_TM_CMD_APP2DEV_NOTIFICATIONS, this
+ *      flag enables (if present) or disables (if not) the forwarding
+ *      to userspace.
  */
 enum iwl_tm_attr_t {
         IWL_TM_ATTR_NOT_APPLICABLE              = 0,
@@ -282,7 +290,8 @@ enum iwl_tm_attr_t {
         IWL_TM_ATTR_FW_INST_SIZE                = 21,
         IWL_TM_ATTR_FW_DATA_SIZE                = 22,
         IWL_TM_ATTR_UCODE_CMD_SKB               = 23,
-        IWL_TM_ATTR_MAX                         = 24,
+        IWL_TM_ATTR_ENABLE_NOTIFICATION         = 24,
+        IWL_TM_ATTR_MAX                         = 25,
 };
 
 /* uCode trace buffer */