net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)

BugLink: http://bugs.launchpad.net/bugs/1635721

This is a driver for the ENA family of networking devices.
Signed-off-by: Netanel Belgazal <netanel@annapurnalabs.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(back-ported from commit 1738cd3e linux-next)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>

Documentation/networking/00-INDEX

@@ -72,6 +72,8 @@ dns_resolver.txt
 	- The DNS resolver module allows kernel servies to make DNS queries.
 driver.txt
 	- Softnet driver issues.
+ena.txt
+	- info on Amazon's Elastic Network Adapter (ENA)
 e100.txt
 	- info on Intel's EtherExpress PRO/100 line of 10/100 boards
 e1000.txt

MAINTAINERS

@@ -606,6 +606,15 @@ F:	drivers/tty/serial/altera_jtaguart.c
 F:	include/linux/altera_uart.h
 F:	include/linux/altera_jtaguart.h
 
+AMAZON ETHERNET DRIVERS
+M:	Netanel Belgazal <netanel@annapurnalabs.com>
+R:	Saeed Bishara <saeed@annapurnalabs.com>
+R:	Zorik Machulsky <zorik@annapurnalabs.com>
+L:	netdev@vger.kernel.org
+S:	Supported
+F:	Documentation/networking/ena.txt
+F:	drivers/net/ethernet/amazon/
+
 AMD CRYPTOGRAPHIC COPROCESSOR (CCP) DRIVER
 M:	Tom Lendacky <thomas.lendacky@amd.com>
 L:	linux-crypto@vger.kernel.org

drivers/net/ethernet/Kconfig

@@ -24,6 +24,7 @@ source "drivers/net/ethernet/agere/Kconfig"
 source "drivers/net/ethernet/allwinner/Kconfig"
 source "drivers/net/ethernet/alteon/Kconfig"
 source "drivers/net/ethernet/altera/Kconfig"
+source "drivers/net/ethernet/amazon/Kconfig"
 source "drivers/net/ethernet/amd/Kconfig"
 source "drivers/net/ethernet/apm/Kconfig"
 source "drivers/net/ethernet/apple/Kconfig"

drivers/net/ethernet/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_NET_VENDOR_AGERE) += agere/
 obj-$(CONFIG_NET_VENDOR_ALLWINNER) += allwinner/
 obj-$(CONFIG_NET_VENDOR_ALTEON) += alteon/
 obj-$(CONFIG_ALTERA_TSE) += altera/
+obj-$(CONFIG_NET_VENDOR_AMAZON) += amazon/
 obj-$(CONFIG_NET_VENDOR_AMD) += amd/
 obj-$(CONFIG_NET_XGENE) += apm/
 obj-$(CONFIG_NET_VENDOR_APPLE) += apple/

drivers/net/ethernet/amazon/Kconfig

+#
+# Amazon network device configuration
+#
+
+config NET_VENDOR_AMAZON
+	bool "Amazon Devices"
+	default y
+	---help---
+	  If you have a network (Ethernet) device belonging to this class, say Y.
+
+	  Note that the answer to this question doesn't directly affect the
+	  kernel: saying N will just cause the configurator to skip all
+	  the questions about Amazon devices. If you say Y, you will be asked
+	  for your specific device in the following questions.
+
+if NET_VENDOR_AMAZON
+
+config ENA_ETHERNET
+	tristate "Elastic Network Adapter (ENA) support"
+	depends on (PCI_MSI && X86)
+	---help---
+	  This driver supports Elastic Network Adapter (ENA)"
+
+	  To compile this driver as a module, choose M here.
+	  The module will be called ena.
+
+endif #NET_VENDOR_AMAZON

drivers/net/ethernet/amazon/Makefile

+#
+# Makefile for the Amazon network device drivers.
+#
+
+obj-$(CONFIG_ENA_ETHERNET) += ena/

drivers/net/ethernet/amazon/ena/Makefile

+#
+# Makefile for the Elastic Network Adapter (ENA) device drivers.
+#
+
+obj-$(CONFIG_ENA_ETHERNET) += ena.o
+
+ena-y := ena_netdev.o ena_com.o ena_eth_com.o ena_ethtool.o

drivers/net/ethernet/amazon/ena/ena_common_defs.h

+/*
+ * Copyright 2015 - 2016 Amazon.com, Inc. or its affiliates.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * BSD license below:
+ *
+ *     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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef _ENA_COMMON_H_
+#define _ENA_COMMON_H_
+
+#define ENA_COMMON_SPEC_VERSION_MAJOR	0 /*  */
+#define ENA_COMMON_SPEC_VERSION_MINOR	10 /*  */
+
+/* ENA operates with 48-bit memory addresses. ena_mem_addr_t */
+struct ena_common_mem_addr {
+	u32 mem_addr_low;
+
+	u16 mem_addr_high;
+
+	/* MBZ */
+	u16 reserved16;
+};
+
+#endif /*_ENA_COMMON_H_ */

drivers/net/ethernet/amazon/ena/ena_eth_com.h

+/*
+ * Copyright 2015 Amazon.com, Inc. or its affiliates.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * BSD license below:
+ *
+ *     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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef ENA_ETH_COM_H_
+#define ENA_ETH_COM_H_
+
+#include "ena_com.h"
+
+/* head update threshold in units of (queue size / ENA_COMP_HEAD_THRESH) */
+#define ENA_COMP_HEAD_THRESH 4
+
+struct ena_com_tx_ctx {
+	struct ena_com_tx_meta ena_meta;
+	struct ena_com_buf *ena_bufs;
+	/* For LLQ, header buffer - pushed to the device mem space */
+	void *push_header;
+
+	enum ena_eth_io_l3_proto_index l3_proto;
+	enum ena_eth_io_l4_proto_index l4_proto;
+	u16 num_bufs;
+	u16 req_id;
+	/* For regular queue, indicate the size of the header
+	 * For LLQ, indicate the size of the pushed buffer
+	 */
+	u16 header_len;
+
+	u8 meta_valid;
+	u8 tso_enable;
+	u8 l3_csum_enable;
+	u8 l4_csum_enable;
+	u8 l4_csum_partial;
+	u8 df; /* Don't fragment */
+};
+
+struct ena_com_rx_ctx {
+	struct ena_com_rx_buf_info *ena_bufs;
+	enum ena_eth_io_l3_proto_index l3_proto;
+	enum ena_eth_io_l4_proto_index l4_proto;
+	bool l3_csum_err;
+	bool l4_csum_err;
+	/* fragmented packet */
+	bool frag;
+	u32 hash;
+	u16 descs;
+	int max_bufs;
+};
+
+int ena_com_prepare_tx(struct ena_com_io_sq *io_sq,
+		       struct ena_com_tx_ctx *ena_tx_ctx,
+		       int *nb_hw_desc);
+
+int ena_com_rx_pkt(struct ena_com_io_cq *io_cq,
+		   struct ena_com_io_sq *io_sq,
+		   struct ena_com_rx_ctx *ena_rx_ctx);
+
+int ena_com_add_single_rx_desc(struct ena_com_io_sq *io_sq,
+			       struct ena_com_buf *ena_buf,
+			       u16 req_id);
+
+int ena_com_tx_comp_req_id_get(struct ena_com_io_cq *io_cq, u16 *req_id);
+
+static inline void ena_com_unmask_intr(struct ena_com_io_cq *io_cq,
+				       struct ena_eth_io_intr_reg *intr_reg)
+{
+	writel(intr_reg->intr_control, io_cq->unmask_reg);
+}
+
+static inline int ena_com_sq_empty_space(struct ena_com_io_sq *io_sq)
+{
+	u16 tail, next_to_comp, cnt;
+
+	next_to_comp = io_sq->next_to_comp;
+	tail = io_sq->tail;
+	cnt = tail - next_to_comp;
+
+	return io_sq->q_depth - 1 - cnt;
+}
+
+static inline int ena_com_write_sq_doorbell(struct ena_com_io_sq *io_sq)
+{
+	u16 tail;
+
+	tail = io_sq->tail;
+
+	pr_debug("write submission queue doorbell for queue: %d tail: %d\n",
+		 io_sq->qid, tail);
+
+	writel(tail, io_sq->db_addr);
+
+	return 0;
+}
+
+static inline int ena_com_update_dev_comp_head(struct ena_com_io_cq *io_cq)
+{
+	u16 unreported_comp, head;
+	bool need_update;
+
+	head = io_cq->head;
+	unreported_comp = head - io_cq->last_head_update;
+	need_update = unreported_comp > (io_cq->q_depth / ENA_COMP_HEAD_THRESH);
+
+	if (io_cq->cq_head_db_reg && need_update) {
+		pr_debug("Write completion queue doorbell for queue %d: head: %d\n",
+			 io_cq->qid, head);
+		writel(head, io_cq->cq_head_db_reg);
+		io_cq->last_head_update = head;
+	}
+
+	return 0;
+}
+
+static inline void ena_com_update_numa_node(struct ena_com_io_cq *io_cq,
+					    u8 numa_node)
+{
+	struct ena_eth_io_numa_node_cfg_reg numa_cfg;
+
+	if (!io_cq->numa_node_cfg_reg)
+		return;
+
+	numa_cfg.numa_cfg = (numa_node & ENA_ETH_IO_NUMA_NODE_CFG_REG_NUMA_MASK)
+		| ENA_ETH_IO_NUMA_NODE_CFG_REG_ENABLED_MASK;
+
+	writel(numa_cfg.numa_cfg, io_cq->numa_node_cfg_reg);
+}
+
+static inline void ena_com_comp_ack(struct ena_com_io_sq *io_sq, u16 elem)
+{
+	io_sq->next_to_comp += elem;
+}
+
+#endif /* ENA_ETH_COM_H_ */