iwlwifi: pcie: introduce a000 TX queues management

In a000 devices the TX handling is different in a few ways:
* Queues are allocated dynamically
* DQA is enabled by default
* Driver shouldn't access TFH registers - ucode configures it
  all in SCD_QUEUE_CFG command

Support all this in a new API with op mode, where op mode sends
the command, transport will allocate the queue dynamically, fill
in DMA properties, send the command to FW and get the ID back.
Current implementation only sets the new transport API and fills
the DMA properties.
Future patches will complete the other parts.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

1 files changed, 162 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
new file mode 100644
index 000000000000..7c93f266871e
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
@@ -0,0 +1,162 @@
+/******************************************************************************
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2017 Intel Deutschland GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2017 Intel Deutschland GmbH
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  * Neither the name Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *****************************************************************************/
+
+#include "iwl-debug.h"
+#include "iwl-csr.h"
+#include "iwl-io.h"
+#include "internal.h"
+
+/*
+ * iwl_pcie_gen2_txq_unmap -  Unmap any remaining DMA mappings and free skb's
+ */
+void iwl_pcie_gen2_txq_unmap(struct iwl_trans *trans, int txq_id)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_txq *txq = &trans_pcie->txq[txq_id];
+
+	spin_lock_bh(&txq->lock);
+	while (txq->write_ptr != txq->read_ptr) {
+		IWL_DEBUG_TX_REPLY(trans, "Q %d Free %d\n",
+				   txq_id, txq->read_ptr);
+
+		iwl_pcie_txq_free_tfd(trans, txq);
+		txq->read_ptr = iwl_queue_inc_wrap(txq->read_ptr);
+
+		if (txq->read_ptr == txq->write_ptr) {
+			unsigned long flags;
+
+			spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+			if (txq_id != trans_pcie->cmd_queue) {
+				IWL_DEBUG_RPM(trans, "Q %d - last tx freed\n",
+					      txq->id);
+				iwl_trans_unref(trans);
+			} else if (trans_pcie->ref_cmd_in_flight) {
+				trans_pcie->ref_cmd_in_flight = false;
+				IWL_DEBUG_RPM(trans,
+					      "clear ref_cmd_in_flight\n");
+				iwl_trans_unref(trans);
+			}
+			spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
+		}
+	}
+	spin_unlock_bh(&txq->lock);
+
+	/* just in case - this queue may have been stopped */
+	iwl_wake_queue(trans, txq);
+}
+
+int iwl_trans_pcie_dyn_txq_alloc(struct iwl_trans *trans,
+				 struct iwl_tx_queue_cfg_cmd *cmd,
+				 int cmd_id,
+				 unsigned int timeout)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	struct iwl_txq *txq = &trans_pcie->txq[cmd->scd_queue];
+	struct iwl_host_cmd hcmd = {
+		.id = cmd_id,
+		.len = { sizeof(*cmd) },
+		.data = { cmd, },
+		.flags = 0,
+	};
+	u16 ssn = le16_to_cpu(cmd->ssn);
+
+	if (test_and_set_bit(cmd->scd_queue, trans_pcie->queue_used)) {
+		WARN_ONCE(1, "queue %d already used", cmd->scd_queue);
+		return -EINVAL;
+	}
+
+	txq->wd_timeout = msecs_to_jiffies(timeout);
+
+	/*
+	 * Place first TFD at index corresponding to start sequence number.
+	 * Assumes that ssn_idx is valid (!= 0xFFF)
+	 */
+	txq->read_ptr = (ssn & 0xff);
+	txq->write_ptr = (ssn & 0xff);
+	iwl_write_direct32(trans, HBUS_TARG_WRPTR,
+			   (ssn & 0xff) | (cmd->scd_queue << 8));
+
+	IWL_DEBUG_TX_QUEUES(trans, "Activate queue %d WrPtr: %d\n",
+			    cmd->scd_queue, ssn & 0xff);
+
+	cmd->tfdq_addr = cpu_to_le64(txq->dma_addr);
+	cmd->byte_cnt_addr = cpu_to_le64(trans_pcie->scd_bc_tbls.dma +
+					 cmd->scd_queue *
+					 sizeof(struct iwlagn_scd_bc_tbl));
+	cmd->cb_size = cpu_to_le64(TFD_QUEUE_CB_SIZE(TFD_QUEUE_SIZE_MAX));
+
+	return iwl_trans_send_cmd(trans, &hcmd);
+}
+
+void iwl_trans_pcie_dyn_txq_free(struct iwl_trans *trans, int queue)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+
+	trans_pcie->txq[queue].frozen_expiry_remainder = 0;
+	trans_pcie->txq[queue].frozen = false;
+
+	/*
+	 * Upon HW Rfkill - we stop the device, and then stop the queues
+	 * in the op_mode. Just for the sake of the simplicity of the op_mode,
+	 * allow the op_mode to call txq_disable after it already called
+	 * stop_device.
+	 */
+	if (!test_and_clear_bit(queue, trans_pcie->queue_used)) {
+		WARN_ONCE(test_bit(STATUS_DEVICE_ENABLED, &trans->status),
+			  "queue %d not used", queue);
+		return;
+	}
+
+	iwl_pcie_gen2_txq_unmap(trans, queue);
+
+	IWL_DEBUG_TX_QUEUES(trans, "Deactivate queue %d\n", queue);
+}
+