[net-next v5 14/15] iecm: Add iecm to the kernel build system

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Alice Michael <alice.michael@intel.com>

This introduces iecm as a module to the kernel, and adds
relevant documentation.

Signed-off-by: Alice Michael <alice.michael@intel.com>
Signed-off-by: Alan Brady <alan.brady@intel.com>
Signed-off-by: Phani Burra <phani.r.burra@intel.com>
Signed-off-by: Joshua Hay <joshua.a.hay@intel.com>
Signed-off-by: Madhu Chittim <madhu.chittim@intel.com>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
Reviewed-by: Donald Skidmore <donald.c.skidmore@intel.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 .../device_drivers/ethernet/intel/iecm.rst    | 93 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 drivers/net/ethernet/intel/Kconfig            | 10 ++
 drivers/net/ethernet/intel/Makefile           |  1 +
 drivers/net/ethernet/intel/iecm/Makefile      | 18 ++++
 5 files changed, 123 insertions(+)
 create mode 100644 Documentation/networking/device_drivers/ethernet/intel/iecm.rst
 create mode 100644 drivers/net/ethernet/intel/iecm/Makefile

diff --git a/Documentation/networking/device_drivers/ethernet/intel/iecm.rst b/Documentation/networking/device_drivers/ethernet/intel/iecm.rst
new file mode 100644
index 000000000000..aefa6bd1094d
--- /dev/null
+++ b/Documentation/networking/device_drivers/ethernet/intel/iecm.rst
@@ -0,0 +1,93 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================
+Intel Ethernet Common Module
+============================
+
+The Intel Ethernet Common Module is meant to serve as an abstraction layer
+between device specific implementation details and common net device driver
+flows. This library provides several function hooks which allow a device driver
+to specify register addresses, control queue communications, and other device
+specific functionality.  Some functions are required to be implemented while
+others have a default implementation that is used when none is supplied by the
+device driver.  Doing this, a device driver can be written to take advantage
+of existing code while also giving the flexibility to implement device specific
+features.
+
+The common use case for this library is for a network device driver that wants
+to specify its own device specific details but also leverage the more common
+code flows found in network device drivers.
+
+Sections in this document:
+	Entry Point
+	Exit Point
+	Register Operations API
+	Virtchnl Operations API
+
+Entry Point
+~~~~~~~~~~~
+The primary entry point to the library is the iecm_probe function.  Prior to
+calling this, device drivers must have allocated an iecm_adapter struct and
+initialized it with the required API functions.  The adapter struct, along with
+the pci_dev struct and the pci_device_id struct, is provided to iecm_probe
+which finalizes device initialization and prepares the device for open.
+
+The iecm_dev_ops struct within the iecm_adapter struct is the primary vehicle
+for passing information from device drivers to the common module.  A dependent
+module must define and assign a reg_ops_init function which will assign the
+respective function pointers to initialize register values (see iecm_reg_ops
+struct).  These are required to be provided by the dependent device driver as
+no suitable default can be assumed for register addresses.
+
+The vc_ops_init function pointer and the related iecm_virtchnl_ops struct are
+optional and should only be necessary for device drivers which use a different
+method/timing for communicating across a mailbox to the hardware.  Within iecm
+is a default interface provided in the case where one is not provided by the
+device driver.
+
+Exit Point
+~~~~~~~~~~
+When the device driver is being prepared to be removed through the pci_driver
+remove callback, it is required for the device driver to call iecm_remove with
+the pci_dev struct provided.  This is required to ensure all resources are
+properly freed and returned to the operating system.
+
+Register Operations API
+~~~~~~~~~~~~~~~~~~~~~~~
+iecm_reg_ops contains three different function pointers relating to initializing
+registers for the specific net device using the library.
+
+ctlq_reg_init relates specifically to setting up registers related to control
+queue/mailbox communications.  Registers that should be defined include: head,
+tail, len, bah, bal, len_mask, len_ena_mask, and head_mask.
+
+vportq_reg_init relates to setting up queue registers.  The tail registers to
+be assigned to the iecm_queue struct for each RX/TX queue.
+
+intr_reg_init relates to any registers needed to setup interrupts.  These
+include registers needed to enable the interrupt and change ITR settings.
+
+If the initialization function finds that one or more required function
+pointers were not provided, an error will be issued and the device will be
+inoperable.
+
+
+Virtchnl Operations API
+~~~~~~~~~~~~~~~~~~~~~~~
+The virtchnl is a conduit between driver and hardware that allows device
+drivers to send and receive control messages to/from hardware.  This is
+optional to be specified as there is a general interface that can be assumed
+when using this library.  However, if a device deviates in some way to
+communicate across the mailbox correctly, this interface is provided to allow
+that.
+
+If vc_ops_init is set in the dev_ops field of the iecm_adapter struct, then it
+is assumed the device driver is providing its own interface to do virtchnl
+communications.  While providing vc_ops_init is optional, if it is provided, it
+is required that the device driver provide function pointers for those functions
+in vc_ops, with exception for the enable_vport, disable_vport, and destroy_vport
+functions which may not be required for all devices.
+
+If the initialization function finds that vc_ops_init was defined but one or
+more required function pointers were not provided, an error will be issued and
+the device will be inoperable.
diff --git a/MAINTAINERS b/MAINTAINERS
index 36ec0bd50a8f..88a52a276eee 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8753,6 +8753,7 @@ F:	Documentation/networking/device_drivers/ethernet/intel/
 F:	drivers/net/ethernet/intel/
 F:	drivers/net/ethernet/intel/*/
 F:	include/linux/avf/virtchnl.h
+F:	include/linux/net/intel/
 
 INTEL FRAMEBUFFER DRIVER (excluding 810 and 815)
 M:	Maik Broemme <mbroemme@libmpq.org>
diff --git a/drivers/net/ethernet/intel/Kconfig b/drivers/net/ethernet/intel/Kconfig
index 5aa86318ed3e..04de64ecb06d 100644
--- a/drivers/net/ethernet/intel/Kconfig
+++ b/drivers/net/ethernet/intel/Kconfig
@@ -343,4 +343,14 @@ config IGC
 	  To compile this driver as a module, choose M here. The module
 	  will be called igc.
 
+config IECM
+	tristate "Intel(R) Ethernet Common Module Support"
+	default n
+	depends on PCI
+	help
+	 To compile this driver as a module, choose M here. The module
+	 will be called iecm.  MSI-X interrupt support is required
+
+	  More specific information on configuring the driver is in
+	  <file:Documentation/networking/device_drivers/ethernet/intel/iecm.rst>.
 endif # NET_VENDOR_INTEL
diff --git a/drivers/net/ethernet/intel/Makefile b/drivers/net/ethernet/intel/Makefile
index 3075290063f6..c9eba9cc5087 100644
--- a/drivers/net/ethernet/intel/Makefile
+++ b/drivers/net/ethernet/intel/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_IXGB) += ixgb/
 obj-$(CONFIG_IAVF) += iavf/
 obj-$(CONFIG_FM10K) += fm10k/
 obj-$(CONFIG_ICE) += ice/
+obj-$(CONFIG_IECM) += iecm/
diff --git a/drivers/net/ethernet/intel/iecm/Makefile b/drivers/net/ethernet/intel/iecm/Makefile
new file mode 100644
index 000000000000..ace32cb7472c
--- /dev/null
+++ b/drivers/net/ethernet/intel/iecm/Makefile
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright (C) 2020 Intel Corporation
+
+#
+# Makefile for the Intel(R) Ethernet Common Module
+#
+
+obj-$(CONFIG_IECM) += iecm.o
+
+iecm-y := \
+	iecm_lib.o \
+	iecm_virtchnl.o \
+	iecm_txrx.o \
+	iecm_singleq_txrx.o \
+	iecm_ethtool.o \
+	iecm_controlq.o \
+	iecm_controlq_setup.o \
+	iecm_main.o
-- 
2.26.2