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* [PATCH 00/19] Implement NTB Controller using multiple PCI EP
@ 2020-05-14 14:59 Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 01/19] dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device Kishon Vijay Abraham I
                   ` (19 more replies)
  0 siblings, 20 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

This series is about implementing SW defined NTB using
multiple endpoint instances. This series has been tested using
2 endpoint instances in J7 connected to two DRA7 boards. However there
is nothing platform specific for the NTB functionality.

This was presented in Linux Plumbers Conference. The presentation
can be found @ [1]

RFC patch series can be found @ [2]

This series has been validated after applying [3] and [4]

Changes from RFC:
1) Converted the DT binding patches to YAML schema and merged the
   DT binding patches together
2) NTB documentation is converted to .rst
3) One HOST can now interrupt the other HOST using MSI-X interrupts
4) Added support for teardown of memory window and doorbell
   configuration
5) Add support to provide support 64-bit memory window size from
   DT

[1] -> https://www.linuxplumbersconf.org/event/4/contributions/395/attachments/284/481/Implementing_NTB_Controller_Using_PCIe_Endpoint_-_final.pdf
[2] -> http://lore.kernel.org/r/20190926112933.8922-1-kishon@ti.com
[3] -> http://lore.kernel.org/r/20200508130646.23939-1-kishon@ti.com
[4] -> http://lore.kernel.org/r/20200506151429.12255-1-kishon@ti.com

Kishon Vijay Abraham I (19):
  dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device
  Documentation: PCI: Add specification for the *PCI NTB* function
    device
  PCI: endpoint: Add API to get reference to EPC from device-tree
  PCI: endpoint: Add API to create EPF device from device tree
  PCI: endpoint: Add "pci-epf-bus" driver
  PCI: endpoint: Make *_get_first_free_bar() take into account 64 bit
    BAR
  PCI: endpoint: Add helper API to get the 'next' unreserved BAR
  PCI: endpoint: Make *_free_bar() to return error codes on failure
  PCI: endpoint: Remove unused pci_epf_match_device()
  PCI: endpoint: Make pci_epf_driver ops optional
  PCI: endpoint: Add helper API to populate header with values from DT
  PCI: endpoint: Add support to associate secondary EPC with EPF
  PCI: endpoint: Add pci_epc_ops to map MSI irq
  PCI: cadence: Implement ->msi_map_irq() ops
  PCI: endpoint: Add EP function driver to provide NTB functionality
  PCI: Add TI J721E device to pci ids
  NTB: Add support for EPF PCI-Express Non-Transparent Bridge
  NTB: tool: Enable the NTB/PCIe link on the local or remote side of
    bridge
  NTB: ntb_perf/ntb_tool: Use PCI device for dma_alloc_coherent()

 Documentation/PCI/endpoint/index.rst          |    1 +
 Documentation/PCI/endpoint/pci-test-ntb.rst   |  344 +++
 .../bindings/pci/endpoint/pci-epf-bus.yaml    |   42 +
 .../bindings/pci/endpoint/pci-epf-device.yaml |   69 +
 .../bindings/pci/endpoint/pci-epf-ntb.yaml    |   68 +
 drivers/misc/pci_endpoint_test.c              |    1 -
 drivers/ntb/hw/Kconfig                        |    1 +
 drivers/ntb/hw/Makefile                       |    1 +
 drivers/ntb/hw/epf/Kconfig                    |    5 +
 drivers/ntb/hw/epf/Makefile                   |    1 +
 drivers/ntb/hw/epf/ntb_hw_epf.c               |  752 ++++++
 drivers/ntb/test/ntb_perf.c                   |    3 +-
 drivers/ntb/test/ntb_tool.c                   |    4 +-
 .../pci/controller/cadence/pcie-cadence-ep.c  |   50 +
 drivers/pci/endpoint/Makefile                 |    3 +-
 drivers/pci/endpoint/functions/Kconfig        |   12 +
 drivers/pci/endpoint/functions/Makefile       |    1 +
 drivers/pci/endpoint/functions/pci-epf-ntb.c  | 2038 +++++++++++++++++
 drivers/pci/endpoint/functions/pci-epf-test.c |   13 +-
 drivers/pci/endpoint/pci-ep-cfs.c             |    6 +-
 drivers/pci/endpoint/pci-epc-core.c           |  216 +-
 drivers/pci/endpoint/pci-epf-bus.c            |   54 +
 drivers/pci/endpoint/pci-epf-core.c           |  137 +-
 include/linux/pci-epc.h                       |   43 +-
 include/linux/pci-epf.h                       |   26 +-
 include/linux/pci_ids.h                       |    1 +
 26 files changed, 3823 insertions(+), 69 deletions(-)
 create mode 100644 Documentation/PCI/endpoint/pci-test-ntb.rst
 create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml
 create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml
 create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml
 create mode 100644 drivers/ntb/hw/epf/Kconfig
 create mode 100644 drivers/ntb/hw/epf/Makefile
 create mode 100644 drivers/ntb/hw/epf/ntb_hw_epf.c
 create mode 100644 drivers/pci/endpoint/functions/pci-epf-ntb.c
 create mode 100644 drivers/pci/endpoint/pci-epf-bus.c

-- 
2.17.1


^ permalink raw reply	[flat|nested] 24+ messages in thread

* [PATCH 01/19] dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-15  2:38   ` Rob Herring
  2020-05-22  5:53   ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 02/19] Documentation: PCI: Add specification for the *PCI NTB* function device Kishon Vijay Abraham I
                   ` (18 subsequent siblings)
  19 siblings, 2 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add device tree schema for PCI endpoint function bus to which
endpoint function devices should be attached. Then add device tree
schema for PCI endpoint function device to include bindings thats
generic to all endpoint functions. Finally add device tree schema
for PCI endpoint NTB function device by including the generic
device tree schema for PCIe endpoint function.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 .../bindings/pci/endpoint/pci-epf-bus.yaml    | 42 +++++++++++
 .../bindings/pci/endpoint/pci-epf-device.yaml | 69 +++++++++++++++++++
 .../bindings/pci/endpoint/pci-epf-ntb.yaml    | 68 ++++++++++++++++++
 3 files changed, 179 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml
 create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml
 create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml

diff --git a/Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml
new file mode 100644
index 000000000000..1c504f2e85e4
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/endpoint/pci-epf-bus.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: PCI Endpoint Function Bus
+
+maintainers:
+  - Kishon Vijay Abraham I <kishon@ti.com>
+
+properties:
+  compatible:
+    const: pci-epf-bus
+
+patternProperties:
+  "^func@[0-9a-f]+$":
+    type: object
+    description: |
+      PCI Endpoint Function Bus node should have subnodes for each of
+      the implemented endpoint function. It should follow the bindings
+      specified for endpoint function in
+      Documentation/devicetree/bindings/pci/endpoint/
+
+examples:
+  - |
+    epf_bus {
+      compatible = "pci-epf-bus";
+
+      func@0 {
+        compatible = "pci-epf-ntb";
+        epcs = <&pcie0_ep>, <&pcie1_ep>;
+        epc-names = "primary", "secondary";
+        reg = <0>;
+        epf,vendor-id = /bits/ 16 <0x104c>;
+        epf,device-id = /bits/ 16 <0xb00d>;
+        num-mws = <4>;
+        mws-size = <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>;
+      };
+    };
+...
diff --git a/Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml
new file mode 100644
index 000000000000..cee72864c8ca
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/endpoint/pci-epf-device.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: PCI Endpoint Function Device
+
+maintainers:
+  - Kishon Vijay Abraham I <kishon@ti.com>
+
+properties:
+  compatible:
+    const: pci-epf-bus
+
+properties:
+  $nodename:
+    pattern: "^func@"
+
+  epcs:
+    description:
+      Phandle to the endpoint controller device. Should have "2" entries for
+      NTB endpoint function and "1" entry for others.
+    minItems: 1
+    maxItems: 2
+
+  epc-names:
+    description:
+      Must contain an entry for each entry in "epcs" when "epcs" have more than
+      one entry.
+
+  reg:
+    maxItems: 0
+    description: Must contain the index number of the function.
+
+  epf,vendor-id:
+    description:
+      The PCI vendor ID
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint16
+
+  epf,device-id:
+    description:
+      The PCI device ID
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint16
+
+  epf,baseclass-code:
+    description: Code to classify the type of operation the function performs
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint8
+
+  epf,subclass-code:
+    description:
+      Specifies a base class sub-class, which identifies more specifically the
+      operation of the Function
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint8
+
+  epf,subsys-vendor-id:
+    description: Code to identify vendor of the add-in card or subsystem
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint16
+
+  epf,subsys-id:
+    description: Code to specify an id that is specific to a vendor
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint16
diff --git a/Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml
new file mode 100644
index 000000000000..92c2e522b9e5
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml
@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/endpoint/pci-epf-ntb.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: PCI Endpoint NTB Function Device
+
+maintainers:
+  - Kishon Vijay Abraham I <kishon@ti.com>
+
+allOf:
+  - $ref: "pci-epf-device.yaml#"
+
+properties:
+  compatible:
+    const: pci-epf-ntb
+
+  epcs:
+    minItems: 2
+    maxItems: 2
+
+  epc-names:
+    items:
+      - const: primary
+      - const: secondary
+
+  num-mws:
+    description:
+      Specify the number of memory windows
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint8
+    minimum: 1
+    maximum: 4
+
+  mws-size:
+    description:
+      List of 'num-mws' entries containing size of each memory window.
+    minItems: 1
+    maxItems: 4
+
+required:
+  - compatible
+  - epcs
+  - epc-names
+  - epf,vendor-id
+  - epf,device-id
+  - num-mws
+  - mws-size
+
+examples:
+  - |
+    epf_bus {
+      compatible = "pci-epf-bus";
+
+      func@0 {
+        compatible = "pci-epf-ntb";
+        reg = <0>;
+        epcs = <&pcie0_ep>, <&pcie1_ep>;
+        epc-names = "primary", "secondary";
+        epf,vendor-id = /bits/ 16 <0x104c>;
+        epf,device-id = /bits/ 16 <0xb00d>;
+        num-mws = <4>;
+        mws-size = <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>;
+      };
+    };
+...
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 02/19] Documentation: PCI: Add specification for the *PCI NTB* function device
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 01/19] dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 03/19] PCI: endpoint: Add API to get reference to EPC from device-tree Kishon Vijay Abraham I
                   ` (17 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add specification for the *PCI NTB* function device. The endpoint function
driver and the host PCI driver should be created based on this
specification.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 Documentation/PCI/endpoint/index.rst        |   1 +
 Documentation/PCI/endpoint/pci-test-ntb.rst | 344 ++++++++++++++++++++
 2 files changed, 345 insertions(+)
 create mode 100644 Documentation/PCI/endpoint/pci-test-ntb.rst

diff --git a/Documentation/PCI/endpoint/index.rst b/Documentation/PCI/endpoint/index.rst
index d114ea74b444..33c19746cdaa 100644
--- a/Documentation/PCI/endpoint/index.rst
+++ b/Documentation/PCI/endpoint/index.rst
@@ -11,3 +11,4 @@ PCI Endpoint Framework
    pci-endpoint-cfs
    pci-test-function
    pci-test-howto
+   pci-test-ntb
diff --git a/Documentation/PCI/endpoint/pci-test-ntb.rst b/Documentation/PCI/endpoint/pci-test-ntb.rst
new file mode 100644
index 000000000000..28027ad7ec4f
--- /dev/null
+++ b/Documentation/PCI/endpoint/pci-test-ntb.rst
@@ -0,0 +1,344 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+PCI NTB Function
+=================
+
+:Author: Kishon Vijay Abraham I <kishon@ti.com>
+
+PCI NTB Function allows two different systems (or hosts) to communicate
+with each other by configurig the endpoint instances in such a way that
+transactions from one system is routed to the other system.
+
+In the below diagram, PCI NTB function configures the SoC with multiple
+PCIe Endpoint (EP) instances in such a way that transaction from one EP
+controller is routed to the other EP controller. Once PCI NTB function
+configures the SoC with multiple EP instances, HOST1 and HOST2 can
+communicate with each other using SoC as a bridge.
+
+.. code-block:: text
+
+    +-------------+                                   +-------------+
+    |             |                                   |             |
+    |    HOST1    |                                   |    HOST2    |
+    |             |                                   |             |
+    +------^------+                                   +------^------+
+           |                                                 |
+           |                                                 |
+ +---------|-------------------------------------------------|---------+
+ |  +------v------+                                   +------v------+  |
+ |  |             |                                   |             |  |
+ |  |     EP      |                                   |     EP      |  |
+ |  | CONTROLLER1 |                                   | CONTROLLER2 |  |
+ |  |             <----------------------------------->             |  |
+ |  |             |                                   |             |  |
+ |  |             |                                   |             |  |
+ |  |             |  SoC With Multiple EP Instances   |             |  |
+ |  |             |  (Configured using NTB Function)  |             |  |
+ |  +-------------+                                   +-------------+  |
+ +---------------------------------------------------------------------+
+
+Constructs used for Implementing NTB
+====================================
+
+	1) Config Region
+	2) Self Scratchpad Registers
+	3) Peer Scratchpad Registers
+	4) Doorbell Registers
+	5) Memory Window
+
+
+Config Region:
+--------------
+
+Config Region is a construct that is specific to NTB implemented using NTB
+Endpoint Function Driver. The host and endpoint side NTB function driver will
+exchange information with each other using this region. Config Region has
+Control/Status Registers for configuring the Endpoint Controller. Host can
+write into this region for configuring the outbound ATU and to indicate the
+link status. Endpoint can indicate the status of commands issued be host in
+this region. Endpoint can also indicate the scratchpad offset, number of
+memory windows to the host using this region.
+
+The format of Config Region is given below. Each of the fields here are 32
+bits.
+
+.. code-block:: text
+
+	+------------------------+
+	|         COMMAND        |
+	+------------------------+
+	|         ARGUMENT       |
+	+------------------------+
+	|         STATUS         |
+	+------------------------+
+	|         TOPOLOGY       |
+	+------------------------+
+	|    ADDRESS (LOWER 32)  |
+	+------------------------+
+	|    ADDRESS (UPPER 32)  |
+	+------------------------+
+	|           SIZE         |
+	+------------------------+
+	|   NO OF MEMORY WINDOW  |
+	+------------------------+
+	|  MEMORY WINDOW1 OFFSET |
+	+------------------------+
+	|       SPAD OFFSET      |
+	+------------------------+
+	|        SPAD COUNT      |
+	+------------------------+
+	|      DB ENTRY SIZE     |
+	+------------------------+
+	|         DB DATA        |
+	+------------------------+
+	|            :           |
+	+------------------------+
+	|            :           |
+	+------------------------+
+	|         DB DATA        |
+	+------------------------+
+
+
+  COMMAND:
+
+	NTB function supports three commands:
+
+	  CMD_CONFIGURE_DOORBELL (0x1): Command to configure doorbell. Before
+	invoking this command, the host should allocate and initialize
+	MSI/MSI-X vectors (i.e initialize the MSI/MSI-X capability in the
+	Endpoint). The endpoint on receiving this command will configure
+	the outbound ATU such that transaction to DB BAR will be routed
+	to the MSI/MSI-X address programmed by the host. The ARGUMENT
+	register should be populated with number of DBs to configure (in the
+	lower 16 bits) and if MSI or MSI-X should be configured (BIT 16).
+	(TODO: Add support for MSI-X).
+
+	  CMD_CONFIGURE_MW (0x2): Command to configure memory window. The
+	host invokes this command after allocating a buffer that can be
+	accessed by remote host. The allocated address should be programmed
+	in the ADDRESS register (64 bit), the size should be programmed in
+	the SIZE register and the memory window index should be programmed
+	in the ARGUMENT register. The endpoint on receiving this command
+	will configure the outbound ATU such that trasaction to MW BAR
+	will be routed to the address provided by the host.
+
+	  CMD_LINK_UP (0x3): Command to indicate an NTB application is
+	bound to the EP device on the host side. Once the endpoint
+	receives this command from both the hosts, the endpoint will
+	raise an LINK_UP event to both the hosts to indicate the hosts
+	can start communicating with each other.
+
+  ARGUMENT:
+
+	The value of this register is based on the commands issued in
+	command register. See COMMAND section for more information.
+
+  TOPOLOGY:
+
+	Set to NTB_TOPO_B2B_USD for Primary interface
+	Set to NTB_TOPO_B2B_DSD for Secondary interface
+
+  ADDRESS/SIZE:
+
+	Address and Size to be used while configuring the memory window.
+	See "CMD_CONFIGURE_MW" for more info.
+
+  MEMORY WINDOW1 OFFSET:
+
+	Memory Window 1 and Doorbell registers are packed together in the
+	same BAR. The initial portion of the region will have doorbell
+	registers and the latter portion of the region is for memory window 1.
+	This register will specify the offset of the memory window 1.
+
+  NO OF MEMORY WINDOW:
+
+	Specifies the number of memory windows supported by the NTB device.
+
+  SPAD OFFSET:
+
+	Self scratchpad region and config region are packed together in the
+	same BAR. The initial portion of the region will have config region
+	and the latter portion of the region is for self scratchpad. This
+	register will specify the offset of the self scratchpad registers.
+
+  SPAD COUNT:
+
+	Specifies the number of scratchpad registers supported by the NTB
+	device.
+
+  DB ENTRY SIZE:
+
+	Used to determine the offset within the DB BAR that should be written
+	in order to raise doorbell. EPF NTB can use either MSI/MSI-X to
+	ring doorbell (MSI-X support will be added later). MSI uses same
+	address for all the interrupts and MSI-X can provide different
+	addresses for different interrupts. The MSI/MSI-X address is provided
+	by the host and the address it gives is based on the MSI/MSI-X
+	implementation supported by the host. For instance, ARM platform
+	using GIC ITS will have same MSI-X address for all the interrupts.
+	In order to support all the combinations and use the same mechanism
+	for both MSI and MSI-X, EPF NTB allocates separate region in the
+	Outbound Address Space for each of the interrupts. This region will
+	be mapped to the MSI/MSI-X address provided by the host. If a host
+	provides the same address for all the interrupts, all the regions
+	will be translated to the same address. If a host provides different
+	address, the regions will be translated to different address. This
+	will ensure there is no difference while raising the doorbell.
+
+  DB DATA:
+
+	EPF NTB supports 32 interrupts. So there are 32 DB DATA registers.
+	This holds the MSI/MSI-X data that has to be written to MSI address
+	for raising doorbell interrupt. This will be populated by EPF NTB
+	while invoking CMD_CONFIGURE_DOORBELL.
+
+Scratchpad Registers:
+---------------------
+
+  Each host has it's own register space allocated in the memory of NTB EPC.
+  They are both readable and writable from both sides of the bridge. They
+  are used by applications built over NTB and can be used to pass control
+  and status information between both sides of a device.
+
+  Scratchpad registers has 2 parts
+	1) Self Scratchpad: Host's own register space
+	2) Peer Scratchpad: Remote host's register space.
+
+Doorbell Registers:
+-------------------
+
+  Registers using which one host can interrupt the other host.
+
+Memory Window:
+--------------
+
+  Actual transfer of data between the two hosts will happen using the
+  memory window.
+
+Modeling Constructs:
+====================
+
+There are 5 or more distinct regions (config, self scratchpad, peer
+scratchpad, doorbell, one or more memory windows) to be modeled to achieve
+NTB functionality. Atleast one memory window is required while more than
+one is permitted. All these regions should be mapped to BAR for hosts to
+access these regions.
+
+If one 32-bit BAR is allocated for each of these regions, the scheme would
+look like
+
+======  ===============
+BAR NO  CONSTRUCTS USED
+======  ===============
+BAR0    Config Region
+BAR1    Self Scratchpad
+BAR2    Peer Scratchpad
+BAR3    Doorbell
+BAR4    Memory Window 1
+BAR5    Memory Window 2
+======  ===============
+
+However if we allocate a separate BAR for each of the region, there would not
+be enough BARs for all the regions in a platform that supports only 64-bit
+BAR.
+
+In order to be be supported by most of the platforms, the regions should be
+packed and mapped to BARs in a way that provides NTB functionality and
+also making sure the hosts doesn't access any region that it is not supposed
+to.
+
+The following scheme is used in EPF NTB Function
+
+======  ===============================
+BAR NO  CONSTRUCTS USED
+======  ===============================
+BAR0    Config Region + Self Scratchpad
+BAR1    Peer Scratchpad
+BAR2    Doorbell + Memory Window 1
+BAR3    Memory Window 2
+BAR4    Memory Window 3
+BAR5    Memory Window 4
+======  ===============================
+
+With this scheme, for the basic NTB functionality 3 BARs should be sufficient.
+
+Modeling Config/Scratchpad Region:
+----------------------------------
+
+.. code-block:: text
+
+ +-----------------+------->+------------------+        +-----------------+
+ |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
+ +-----------------+----+   +------------------+<-------+-----------------+
+ |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
+ +-----------------+    +-->+------------------+<-------+-----------------+
+ |       BAR2      |            Local Memory            |       BAR2      |
+ +-----------------+                                    +-----------------+
+ |       BAR3      |                                    |       BAR3      |
+ +-----------------+                                    +-----------------+
+ |       BAR4      |                                    |       BAR4      |
+ +-----------------+                                    +-----------------+
+ |       BAR5      |                                    |       BAR5      |
+ +-----------------+                                    +-----------------+
+   EP CONTROLLER 1                                        EP CONTROLLER 2
+
+Above diagram shows Config region + Scratchpad region for HOST1 (connected to
+EP controller 1) allocated in local memory. The HOST1 can access the config
+region and scratchpad region (self scratchpad) using BAR0 of EP controller 1.
+The peer host (HOST2 connected to EP controller 2) can also access this
+scratchpad region (peer scratchpad) using BAR1 of EP controller 2. This
+diagram shows the case where Config region and Scratchpad region is allocated
+for HOST1, however the same is applicable for HOST2.
+
+Modeling Doorbell/Memory Window 1:
+----------------------------------
+
+.. code-block:: text
+
+ +-----------------+    +----->+----------------+-----------+-----------------+
+ |       BAR0      |    |      |   Doorbell 1   +-----------> MSI-X ADDRESS 1 |
+ +-----------------+    |      +----------------+           +-----------------+
+ |       BAR1      |    |      |   Doorbell 2   +---------+ |                 |
+ +-----------------+----+      +----------------+         | |                 |
+ |       BAR2      |           |   Doorbell 3   +-------+ | +-----------------+
+ +-----------------+----+      +----------------+       | +-> MSI-X ADDRESS 2 |
+ |       BAR3      |    |      |   Doorbell 4   +-----+ |   +-----------------+
+ +-----------------+    |      |----------------+     | |   |                 |
+ |       BAR4      |    |      |                |     | |   +-----------------+
+ +-----------------+    |      |      MW1       +---+ | +-->+ MSI-X ADDRESS 3||
+ |       BAR5      |    |      |                |   | |     +-----------------+
+ +-----------------+    +----->-----------------+   | |     |                 |
+   EP CONTROLLER 1             |                |   | |     +-----------------+
+                               |                |   | +---->+ MSI-X ADDRESS 4 |
+                               +----------------+   |       +-----------------+
+                                EP CONTROLLER 2     |       |                 |
+                                  (OB SPACE)        |       |                 |
+                                                    +------->      MW1        |
+                                                            |                 |
+                                                            |                 |
+                                                            +-----------------+
+                                                            |                 |
+                                                            |                 |
+                                                            |                 |
+                                                            |                 |
+                                                            |                 |
+                                                            +-----------------+
+                                                             PCI Address Space
+                                                             (Managed by HOST2)
+
+Above diagram shows how the doorbell and memory window 1 is mapped so that
+HOST1 can raise doorbell interrupt on HOST2 and also how HOST1 can access
+buffers exposed by HOST2 using memory window1 (MW1). Here doorbell and
+memory window 1 regions are allocated in EP controller 2 outbound (OB) address
+space. Allocating and configuring BARs for doorbell and memory window1
+is done during the initialization phase of NTB endpoint function driver.
+Mapping from EP controller 2 OB space to PCI address space is done when HOST2
+sends CMD_CONFIGURE_MW/CMD_CONFIGURE_DOORBELL. The commands are explained
+below.
+
+Modeling Optional Memory Windows:
+---------------------------------
+
+This is modeled the same was as MW1 but each of the additional memory windows
+is mapped to separate BARs.
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 03/19] PCI: endpoint: Add API to get reference to EPC from device-tree
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 01/19] dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 02/19] Documentation: PCI: Add specification for the *PCI NTB* function device Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 04/19] PCI: endpoint: Add API to create EPF device from device tree Kishon Vijay Abraham I
                   ` (16 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add of_pci_epc_get() and of_pci_epc_get_by_name() to get reference
to EPC from device-tree. This is added in preparation to define
an endpoint function device in device tree.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/pci-epc-core.c | 61 +++++++++++++++++++++++++++++
 include/linux/pci-epc.h             |  3 ++
 2 files changed, 64 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 82ba0dc7f2f5..177a3fc1a0dd 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -83,6 +83,66 @@ struct pci_epc *pci_epc_get(const char *epc_name)
 }
 EXPORT_SYMBOL_GPL(pci_epc_get);
 
+/**
+ * of_pci_epc_get() - get PCI endpoint controller from device node and index
+ * @node: device node which contains the phandle to endpoint controller
+ * @index: index of the endpoint controller in "epcs" property
+ *
+ * Returns the EPC corresponding to the _index_ entry in "epcs" property
+ * present in device node, after getting a refcount  to it or -ENODEV if
+ * there is no such EPC or -EPROBE_DEFER if there is a phandle to the phy,
+ * but the device is not yet loaded.
+ */
+struct pci_epc *of_pci_epc_get(struct device_node *node, int index)
+{
+	struct device_node *epc_node;
+	struct class_dev_iter iter;
+	struct pci_epc *epc;
+	struct device *dev;
+
+	epc_node = of_parse_phandle(node, "epcs", index);
+	if (!epc_node)
+		return ERR_PTR(-ENODEV);
+
+	class_dev_iter_init(&iter, pci_epc_class, NULL, NULL);
+	while ((dev = class_dev_iter_next(&iter))) {
+		epc = to_pci_epc(dev);
+		if (epc_node != epc->dev.of_node)
+			continue;
+
+		of_node_put(epc_node);
+		class_dev_iter_exit(&iter);
+		get_device(&epc->dev);
+		return epc;
+	}
+
+	of_node_put(epc_node);
+	class_dev_iter_exit(&iter);
+	return ERR_PTR(-EPROBE_DEFER);
+}
+EXPORT_SYMBOL_GPL(of_pci_epc_get);
+
+/**
+ * of_pci_epc_get_by_name() - get PCI endpoint controller from device node
+ *                            and string
+ * @node: device node which contains the phandle to endpoint controller
+ * @epc_name: name of endpoint controller as present in "epc-names" property
+ *
+ * Returns the EPC corresponding to the epc_name in "epc-names" property
+ * present in device node.
+ */
+struct pci_epc *of_pci_epc_get_by_name(struct device_node *node,
+				       const char *epc_name)
+{
+	int index = 0;
+
+	if (epc_name)
+		index = of_property_match_string(node, "epc-names", epc_name);
+
+	return of_pci_epc_get(node, index);
+}
+EXPORT_SYMBOL_GPL(of_pci_epc_get_by_name);
+
 /**
  * pci_epc_get_first_free_bar() - helper to get first unreserved BAR
  * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
@@ -629,6 +689,7 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
 	device_initialize(&epc->dev);
 	epc->dev.class = pci_epc_class;
 	epc->dev.parent = dev;
+	epc->dev.of_node = dev->of_node;
 	epc->ops = ops;
 
 	ret = dev_set_name(&epc->dev, "%s", dev_name(dev));
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index cc66bec8be90..dd3c2d566c3d 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -211,6 +211,9 @@ int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t base,
 int pci_epc_multi_mem_init(struct pci_epc *epc,
 			   struct pci_epc_mem_window *window,
 			   unsigned int num_windows);
+struct pci_epc *of_pci_epc_get(struct device_node *node, int index);
+struct pci_epc *of_pci_epc_get_by_name(struct device_node *node,
+				       const char *epc_name);
 void pci_epc_mem_exit(struct pci_epc *epc);
 void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
 				     phys_addr_t *phys_addr, size_t size);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 04/19] PCI: endpoint: Add API to create EPF device from device tree
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (2 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 03/19] PCI: endpoint: Add API to get reference to EPC from device-tree Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 05/19] PCI: endpoint: Add "pci-epf-bus" driver Kishon Vijay Abraham I
                   ` (15 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add API to create EPF device from device tree and the device managed
interface corresponding to it. This is added in order to define
an endpoint function completely from device tree.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/pci-epf-core.c | 68 +++++++++++++++++++++++++++++
 include/linux/pci-epf.h             |  6 +++
 2 files changed, 74 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index 244e00f48c5c..cb6c7b886325 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -280,6 +280,73 @@ struct pci_epf *pci_epf_create(const char *name)
 }
 EXPORT_SYMBOL_GPL(pci_epf_create);
 
+/**
+ * pci_epf_of_create() - create a new PCI EPF device from device tree node
+ * @node: the device node of the PCI EPF device.
+ *
+ * Invoke to create a new PCI EPF device by providing a device tree node
+ * with compatible property.
+ */
+struct pci_epf *pci_epf_of_create(struct device_node *node)
+{
+	struct pci_epf *epf;
+	const char *compat;
+	int ret;
+
+	of_node_get(node);
+
+	ret = of_property_read_string(node, "compatible", &compat);
+	if (ret) {
+		of_node_put(node);
+		return ERR_PTR(ret);
+	}
+
+	epf = pci_epf_create(compat);
+	if (!IS_ERR(epf))
+		epf->node = node;
+
+	return epf;
+}
+EXPORT_SYMBOL_GPL(pci_epf_of_create);
+
+static void devm_epf_release(struct device *dev, void *res)
+{
+	struct pci_epf *epf = *(struct pci_epf **)res;
+
+	pci_epf_destroy(epf);
+}
+
+/**
+ * devm_pci_epf_of_create() - create a new PCI EPF device from device tree node
+ * @dev: device that is creating the new EPF
+ * @node: the device node of the PCI EPF device.
+ *
+ * Invoke to create a new PCI EPF device by providing a device tree node with
+ * compatible property. While at that, it also associates the device with the
+ * EPF using devres. On driver detach, release function is invoked on the devres
+ * data, where devres data is freed.
+ */
+struct pci_epf *devm_pci_epf_of_create(struct device *dev,
+				       struct device_node *node)
+{
+	struct pci_epf **ptr, *epf;
+
+	ptr = devres_alloc(devm_epf_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	epf = pci_epf_of_create(node);
+	if (!IS_ERR(epf)) {
+		*ptr = epf;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return epf;
+}
+EXPORT_SYMBOL_GPL(devm_pci_epf_of_create);
+
 const struct pci_epf_device_id *
 pci_epf_match_device(const struct pci_epf_device_id *id, struct pci_epf *epf)
 {
@@ -300,6 +367,7 @@ static void pci_epf_dev_release(struct device *dev)
 {
 	struct pci_epf *epf = to_pci_epf(dev);
 
+	of_node_put(epf->node);
 	kfree(epf->name);
 	kfree(epf);
 }
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 6644ff3b0702..8fb77ab1968f 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -11,6 +11,7 @@
 
 #include <linux/device.h>
 #include <linux/mod_devicetable.h>
+#include <linux/of.h>
 #include <linux/pci.h>
 
 struct pci_epf;
@@ -108,6 +109,7 @@ struct pci_epf_bar {
 /**
  * struct pci_epf - represents the PCI EPF device
  * @dev: the PCI EPF device
+ * @node: the device tree node of the PCI EPF device
  * @name: the name of the PCI EPF device
  * @header: represents standard configuration header
  * @bar: represents the BAR of EPF device
@@ -121,6 +123,7 @@ struct pci_epf_bar {
  */
 struct pci_epf {
 	struct device		dev;
+	struct device_node	*node;
 	const char		*name;
 	struct pci_epf_header	*header;
 	struct pci_epf_bar	bar[6];
@@ -167,6 +170,9 @@ static inline void *epf_get_drvdata(struct pci_epf *epf)
 const struct pci_epf_device_id *
 pci_epf_match_device(const struct pci_epf_device_id *id, struct pci_epf *epf);
 struct pci_epf *pci_epf_create(const char *name);
+struct pci_epf *pci_epf_of_create(struct device_node *node);
+struct pci_epf *devm_pci_epf_of_create(struct device *dev,
+				       struct device_node *node);
 void pci_epf_destroy(struct pci_epf *epf);
 int __pci_epf_register_driver(struct pci_epf_driver *driver,
 			      struct module *owner);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 05/19] PCI: endpoint: Add "pci-epf-bus" driver
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (3 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 04/19] PCI: endpoint: Add API to create EPF device from device tree Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 06/19] PCI: endpoint: Make *_get_first_free_bar() take into account 64 bit BAR Kishon Vijay Abraham I
                   ` (14 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add "pci-epf-bus" driver that helps to create EPF device from
device tree. This is added in order to define an endpoint function
device completely from device tree.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/Makefile      |  3 +-
 drivers/pci/endpoint/pci-epf-bus.c | 54 ++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 drivers/pci/endpoint/pci-epf-bus.c

diff --git a/drivers/pci/endpoint/Makefile b/drivers/pci/endpoint/Makefile
index 95b2fe47e3b0..36cf33cf975c 100644
--- a/drivers/pci/endpoint/Makefile
+++ b/drivers/pci/endpoint/Makefile
@@ -5,4 +5,5 @@
 
 obj-$(CONFIG_PCI_ENDPOINT_CONFIGFS)	+= pci-ep-cfs.o
 obj-$(CONFIG_PCI_ENDPOINT)		+= pci-epc-core.o pci-epf-core.o\
-					   pci-epc-mem.o functions/
+					   pci-epc-mem.o pci-epf-bus.o \
+					   functions/
diff --git a/drivers/pci/endpoint/pci-epf-bus.c b/drivers/pci/endpoint/pci-epf-bus.c
new file mode 100644
index 000000000000..b6ab1479b79e
--- /dev/null
+++ b/drivers/pci/endpoint/pci-epf-bus.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * PCI Endpoint *Function* Bus Driver
+ *
+ * Copyright (C) 2020 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pci-epf.h>
+#include <linux/platform_device.h>
+
+static int pci_epf_bus_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = of_node_get(dev->of_node);
+	struct device_node *child;
+	struct pci_epf *epf;
+
+	for_each_child_of_node(node, child) {
+		epf = devm_pci_epf_of_create(dev, child);
+		if (IS_ERR(epf)) {
+			dev_err(dev, "Failed to create PCI EPF device %s\n",
+				node->full_name);
+			of_node_put(child);
+			break;
+		}
+	}
+	of_node_put(node);
+
+	return 0;
+}
+
+static const struct of_device_id pci_epf_bus_id_table[] = {
+	{ .compatible = "pci-epf-bus" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, pci_epf_bus_id_table);
+
+static struct platform_driver pci_epf_bus_driver = {
+	.probe		= pci_epf_bus_probe,
+	.driver		= {
+		.name	= "pci-epf-bus",
+		.of_match_table = of_match_ptr(pci_epf_bus_id_table),
+	},
+};
+
+module_platform_driver(pci_epf_bus_driver);
+
+MODULE_AUTHOR("Texas Instruments Inc.");
+MODULE_DESCRIPTION("PCI EPF Bus Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 06/19] PCI: endpoint: Make *_get_first_free_bar() take into account 64 bit BAR
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (4 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 05/19] PCI: endpoint: Add "pci-epf-bus" driver Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 07/19] PCI: endpoint: Add helper API to get the 'next' unreserved BAR Kishon Vijay Abraham I
                   ` (13 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

pci_epc_get_first_free_bar() uses only "reserved_bar" member in
epc_features to get the first unreserved BAR. However if the
reserved BAR is also a 64-bit BAR, then the next BAR shouldn't be
returned (since 64-bit BAR uses two BARs).

Make pci_epc_get_first_free_bar() take into account 64 bit BAR while
returning the first free unreserved BAR.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/pci-epc-core.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 177a3fc1a0dd..49bffa2349c5 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -153,12 +153,20 @@ EXPORT_SYMBOL_GPL(of_pci_epc_get_by_name);
 unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
 					*epc_features)
 {
-	int free_bar;
+	unsigned long free_bar;
 
 	if (!epc_features)
 		return 0;
 
-	free_bar = ffz(epc_features->reserved_bar);
+	/* Find if the reserved BAR is also a 64-bit BAR */
+	free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;
+
+	/* Set the adjacent bit if the reserved BAR is also a 64-bit BAR */
+	free_bar <<= 1;
+	free_bar |= epc_features->reserved_bar;
+
+	/* Now find the free BAR */
+	free_bar = ffz(free_bar);
 	if (free_bar > 5)
 		return 0;
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 07/19] PCI: endpoint: Add helper API to get the 'next' unreserved BAR
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (5 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 06/19] PCI: endpoint: Make *_get_first_free_bar() take into account 64 bit BAR Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 08/19] PCI: endpoint: Make *_free_bar() to return error codes on failure Kishon Vijay Abraham I
                   ` (12 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add an API to get the next unreserved BAR starting from a given BAR
number that can be used by the endpoint function.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/pci-epc-core.c | 26 ++++++++++++++++++++++----
 include/linux/pci-epc.h             |  2 ++
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 49bffa2349c5..85e542aae617 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -147,17 +147,36 @@ EXPORT_SYMBOL_GPL(of_pci_epc_get_by_name);
  * pci_epc_get_first_free_bar() - helper to get first unreserved BAR
  * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
  *
- * Invoke to get the first unreserved BAR that can be used for endpoint
+ * Invoke to get the first unreserved BAR that can be used by the endpoint
  * function. For any incorrect value in reserved_bar return '0'.
  */
 unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
 					*epc_features)
+{
+	return pci_epc_get_next_free_bar(epc_features, BAR_0);
+}
+EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
+
+/**
+ * pci_epc_get_next_free_bar() - helper to get unreserved BAR starting from @bar
+ * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
+ * @bar: the starting BAR number from where unreserved BAR should be searched
+ *
+ * Invoke to get the next unreserved BAR starting from @bar that can be used
+ * for endpoint function. For any incorrect value in reserved_bar return '0'.
+ */
+unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
+				       *epc_features, enum pci_barno bar)
 {
 	unsigned long free_bar;
 
 	if (!epc_features)
 		return 0;
 
+	/* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
+	if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
+		bar++;
+
 	/* Find if the reserved BAR is also a 64-bit BAR */
 	free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;
 
@@ -165,14 +184,13 @@ unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
 	free_bar <<= 1;
 	free_bar |= epc_features->reserved_bar;
 
-	/* Now find the free BAR */
-	free_bar = ffz(free_bar);
+	free_bar = find_next_zero_bit(&free_bar, 6, bar);
 	if (free_bar > 5)
 		return 0;
 
 	return free_bar;
 }
-EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
+EXPORT_SYMBOL_GPL(pci_epc_get_next_free_bar);
 
 /**
  * pci_epc_get_features() - get the features supported by EPC
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index dd3c2d566c3d..68f7c0d81442 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -203,6 +203,8 @@ const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
 						    u8 func_no);
 unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
 					*epc_features);
+unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
+				       *epc_features, enum pci_barno bar);
 struct pci_epc *pci_epc_get(const char *epc_name);
 void pci_epc_put(struct pci_epc *epc);
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 08/19] PCI: endpoint: Make *_free_bar() to return error codes on failure
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (6 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 07/19] PCI: endpoint: Add helper API to get the 'next' unreserved BAR Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 09/19] PCI: endpoint: Remove unused pci_epf_match_device() Kishon Vijay Abraham I
                   ` (11 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Modify pci_epc_get_next_free_bar() and pci_epc_get_first_free_bar() to
return error values if there are no free BARs available.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/functions/pci-epf-test.c |  2 ++
 drivers/pci/endpoint/pci-epc-core.c           | 12 ++++++------
 include/linux/pci-epc.h                       |  8 ++++----
 include/linux/pci-epf.h                       |  1 +
 4 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 60330f3e3751..ba43e1e05958 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -831,6 +831,8 @@ static int pci_epf_test_bind(struct pci_epf *epf)
 		linkup_notifier = epc_features->linkup_notifier;
 		core_init_notifier = epc_features->core_init_notifier;
 		test_reg_bar = pci_epc_get_first_free_bar(epc_features);
+		if (test_reg_bar < 0)
+			return -EINVAL;
 		pci_epf_configure_bar(epf, epc_features);
 	}
 
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 85e542aae617..df8789fee01e 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -150,8 +150,8 @@ EXPORT_SYMBOL_GPL(of_pci_epc_get_by_name);
  * Invoke to get the first unreserved BAR that can be used by the endpoint
  * function. For any incorrect value in reserved_bar return '0'.
  */
-unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
-					*epc_features)
+enum pci_barno
+pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features)
 {
 	return pci_epc_get_next_free_bar(epc_features, BAR_0);
 }
@@ -165,13 +165,13 @@ EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
  * Invoke to get the next unreserved BAR starting from @bar that can be used
  * for endpoint function. For any incorrect value in reserved_bar return '0'.
  */
-unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
-				       *epc_features, enum pci_barno bar)
+enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
+					 *epc_features, enum pci_barno bar)
 {
 	unsigned long free_bar;
 
 	if (!epc_features)
-		return 0;
+		return BAR_0;
 
 	/* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
 	if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
@@ -186,7 +186,7 @@ unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
 
 	free_bar = find_next_zero_bit(&free_bar, 6, bar);
 	if (free_bar > 5)
-		return 0;
+		return NO_BAR;
 
 	return free_bar;
 }
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 68f7c0d81442..463586889453 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -201,10 +201,10 @@ int pci_epc_start(struct pci_epc *epc);
 void pci_epc_stop(struct pci_epc *epc);
 const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
 						    u8 func_no);
-unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
-					*epc_features);
-unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
-				       *epc_features, enum pci_barno bar);
+enum pci_barno
+pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features);
+enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
+					 *epc_features, enum pci_barno bar);
 struct pci_epc *pci_epc_get(const char *epc_name);
 void pci_epc_put(struct pci_epc *epc);
 
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 8fb77ab1968f..e51f3070bcc4 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -22,6 +22,7 @@ enum pci_notify_event {
 };
 
 enum pci_barno {
+	NO_BAR = -1,
 	BAR_0,
 	BAR_1,
 	BAR_2,
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 09/19] PCI: endpoint: Remove unused pci_epf_match_device()
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (7 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 08/19] PCI: endpoint: Make *_free_bar() to return error codes on failure Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 10/19] PCI: endpoint: Make pci_epf_driver ops optional Kishon Vijay Abraham I
                   ` (10 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Remove unused pci_epf_match_device() function added in pci-epf-core.c

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/pci-epf-core.c | 16 ----------------
 include/linux/pci-epf.h             |  2 --
 2 files changed, 18 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index cb6c7b886325..f9ba2e8d4a99 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -347,22 +347,6 @@ struct pci_epf *devm_pci_epf_of_create(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_pci_epf_of_create);
 
-const struct pci_epf_device_id *
-pci_epf_match_device(const struct pci_epf_device_id *id, struct pci_epf *epf)
-{
-	if (!id || !epf)
-		return NULL;
-
-	while (*id->name) {
-		if (strcmp(epf->name, id->name) == 0)
-			return id;
-		id++;
-	}
-
-	return NULL;
-}
-EXPORT_SYMBOL_GPL(pci_epf_match_device);
-
 static void pci_epf_dev_release(struct device *dev)
 {
 	struct pci_epf *epf = to_pci_epf(dev);
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index e51f3070bcc4..9bd89f1be1c3 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -168,8 +168,6 @@ static inline void *epf_get_drvdata(struct pci_epf *epf)
 	return dev_get_drvdata(&epf->dev);
 }
 
-const struct pci_epf_device_id *
-pci_epf_match_device(const struct pci_epf_device_id *id, struct pci_epf *epf);
 struct pci_epf *pci_epf_create(const char *name);
 struct pci_epf *pci_epf_of_create(struct device_node *node);
 struct pci_epf *devm_pci_epf_of_create(struct device *dev,
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 10/19] PCI: endpoint: Make pci_epf_driver ops optional
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (8 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 09/19] PCI: endpoint: Remove unused pci_epf_match_device() Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 11/19] PCI: endpoint: Add helper API to populate header with values from DT Kishon Vijay Abraham I
                   ` (9 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

pci_epf_driver had two ops for bind and unbind which will be invoked
when an endpoint controller is bound to an endpoint function (using
configfs). Now that endpoint core has support to define an endpoint
function using device tree alone, the bind and unbind ops can be
optional. Make pci_epf_driver ops optional here.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/pci-epf-core.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index f9ba2e8d4a99..f463eedcc3ad 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -201,11 +201,9 @@ int __pci_epf_register_driver(struct pci_epf_driver *driver,
 {
 	int ret;
 
-	if (!driver->ops)
-		return -EINVAL;
-
-	if (!driver->ops->bind || !driver->ops->unbind)
-		return -EINVAL;
+	if (!driver->ops || !driver->ops->bind || !driver->ops->unbind)
+		pr_debug("%s: Supports only pci_epf device created using DT\n",
+			 driver->driver.name);
 
 	driver->driver.bus = &pci_epf_bus_type;
 	driver->driver.owner = owner;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 11/19] PCI: endpoint: Add helper API to populate header with values from DT
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (9 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 10/19] PCI: endpoint: Make pci_epf_driver ops optional Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 12/19] PCI: endpoint: Add support to associate secondary EPC with EPF Kishon Vijay Abraham I
                   ` (8 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add helper API pci_epc_of_parse_header() to populate header with
values from device tree. These values will be written to the
configuration space header in the endpoint controller.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/pci-epc-core.c | 24 ++++++++++++++++++++++++
 include/linux/pci-epc.h             |  2 ++
 2 files changed, 26 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index df8789fee01e..31a82af397a3 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -31,6 +31,30 @@ static int devm_pci_epc_match(struct device *dev, void *res, void *match_data)
 	return *epc == match_data;
 }
 
+/**
+ * pci_epc_of_parse_header() - parse the device tree to get PCI config space
+ *                             header
+ * @node: The device tree node (of endpoint function) which has the PCI config
+ *        space header values
+ * @header: standard configuration space header fields that has to be populated
+ *
+ * Invoke to populate *header* with the PCI configuration space values populated
+ * in device tree.
+ */
+void pci_epc_of_parse_header(struct device_node *node,
+			     struct pci_epf_header *header)
+{
+	of_property_read_u16(node, "epf,vendor-id", &header->vendorid);
+	of_property_read_u16(node, "epf,device-id", &header->deviceid);
+	of_property_read_u8(node, "epf,baseclass-code",
+			    &header->baseclass_code);
+	of_property_read_u8(node, "epf,subclass-code", &header->subclass_code);
+	of_property_read_u16(node, "epf,subsys-vendor-id",
+			     &header->subsys_vendor_id);
+	of_property_read_u16(node, "epf,subsys-id", &header->subsys_id);
+}
+EXPORT_SYMBOL_GPL(pci_epc_of_parse_header);
+
 /**
  * pci_epc_put() - release the PCI endpoint controller
  * @epc: epc returned by pci_epc_get()
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 463586889453..490a9077df52 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -199,6 +199,8 @@ int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no,
 		      enum pci_epc_irq_type type, u16 interrupt_num);
 int pci_epc_start(struct pci_epc *epc);
 void pci_epc_stop(struct pci_epc *epc);
+void pci_epc_of_parse_header(struct device_node *node,
+			     struct pci_epf_header *header);
 const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
 						    u8 func_no);
 enum pci_barno
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 12/19] PCI: endpoint: Add support to associate secondary EPC with EPF
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (10 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 11/19] PCI: endpoint: Add helper API to populate header with values from DT Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 13/19] PCI: endpoint: Add pci_epc_ops to map MSI irq Kishon Vijay Abraham I
                   ` (7 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

In the case of standard endpoint functions, only one endpoint
controller (EPC) will be associated with an endpoint function
(EPF). However for providing NTB (non transparent bridge)
functionality, two EPCs should be associated with a single EPF.
Add support to associate secondary EPC with EPF. This is in
preparation for adding NTB endpoint function driver.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/functions/pci-epf-test.c | 11 ++--
 drivers/pci/endpoint/pci-ep-cfs.c             |  6 +-
 drivers/pci/endpoint/pci-epc-core.c           | 50 ++++++++++++----
 drivers/pci/endpoint/pci-epf-core.c           | 57 +++++++++++++------
 include/linux/pci-epc.h                       | 25 +++++++-
 include/linux/pci-epf.h                       | 17 +++++-
 6 files changed, 128 insertions(+), 38 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index ba43e1e05958..b79d95f666ff 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -616,7 +616,8 @@ static void pci_epf_test_unbind(struct pci_epf *epf)
 
 		if (epf_test->reg[bar]) {
 			pci_epc_clear_bar(epc, epf->func_no, epf_bar);
-			pci_epf_free_space(epf, epf_test->reg[bar], bar);
+			pci_epf_free_space(epf, epf_test->reg[bar], bar,
+					   PRIMARY_INTERFACE);
 		}
 	}
 }
@@ -648,7 +649,8 @@ static int pci_epf_test_set_bar(struct pci_epf *epf)
 
 		ret = pci_epc_set_bar(epc, epf->func_no, epf_bar);
 		if (ret) {
-			pci_epf_free_space(epf, epf_test->reg[bar], bar);
+			pci_epf_free_space(epf, epf_test->reg[bar], bar,
+					   PRIMARY_INTERFACE);
 			dev_err(dev, "Failed to set BAR%d\n", bar);
 			if (bar == test_reg_bar)
 				return ret;
@@ -768,7 +770,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
 	}
 
 	base = pci_epf_alloc_space(epf, test_reg_size, test_reg_bar,
-				   epc_features->align);
+				   epc_features->align, PRIMARY_INTERFACE);
 	if (!base) {
 		dev_err(dev, "Failed to allocated register space\n");
 		return -ENOMEM;
@@ -786,7 +788,8 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
 			continue;
 
 		base = pci_epf_alloc_space(epf, bar_size[bar], bar,
-					   epc_features->align);
+					   epc_features->align,
+					   PRIMARY_INTERFACE);
 		if (!base)
 			dev_err(dev, "Failed to allocate space for BAR%d\n",
 				bar);
diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
index 55edce50be96..0cd02caedd1c 100644
--- a/drivers/pci/endpoint/pci-ep-cfs.c
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -94,13 +94,13 @@ static int pci_epc_epf_link(struct config_item *epc_item,
 	struct pci_epc *epc = epc_group->epc;
 	struct pci_epf *epf = epf_group->epf;
 
-	ret = pci_epc_add_epf(epc, epf);
+	ret = pci_epc_add_epf(epc, epf, PRIMARY_INTERFACE);
 	if (ret)
 		return ret;
 
 	ret = pci_epf_bind(epf);
 	if (ret) {
-		pci_epc_remove_epf(epc, epf);
+		pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
 		return ret;
 	}
 
@@ -120,7 +120,7 @@ static void pci_epc_epf_unlink(struct config_item *epc_item,
 	epc = epc_group->epc;
 	epf = epf_group->epf;
 	pci_epf_unbind(epf);
-	pci_epc_remove_epf(epc, epf);
+	pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
 }
 
 static struct configfs_item_operations pci_epc_item_ops = {
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 31a82af397a3..bd8f372c506f 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -577,22 +577,32 @@ EXPORT_SYMBOL_GPL(pci_epc_write_header);
  * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller
  * @epc: the EPC device to which the endpoint function should be added
  * @epf: the endpoint function to be added
+ * @type: Identifies if the EPC is connected to the primary or secondary
+ *        interface of EPF
  *
  * A PCI endpoint device can have one or more functions. In the case of PCIe,
  * the specification allows up to 8 PCIe endpoint functions. Invoke
  * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller.
  */
-int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf)
+int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
+		    enum pci_epc_interface_type type)
 {
+	struct list_head *list;
 	u32 func_no;
 	int ret = 0;
 
-	if (epf->epc)
-		return -EBUSY;
-
 	if (IS_ERR(epc))
 		return -EINVAL;
 
+	if (epf->func_no > epc->max_functions - 1)
+		return -EINVAL;
+
+	if (type == PRIMARY_INTERFACE && epf->epc)
+		return -EBUSY;
+
+	if (type == SECONDARY_INTERFACE && epf->sec_epc)
+		return -EBUSY;
+
 	mutex_lock(&epc->lock);
 	func_no = find_first_zero_bit(&epc->function_num_map,
 				      BITS_PER_LONG);
@@ -608,11 +618,17 @@ int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf)
 	}
 
 	set_bit(func_no, &epc->function_num_map);
-	epf->func_no = func_no;
-	epf->epc = epc;
-
-	list_add_tail(&epf->list, &epc->pci_epf);
+	if (type == PRIMARY_INTERFACE) {
+		epf->func_no = func_no;
+		epf->epc = epc;
+		list = &epf->list;
+	} else {
+		epf->sec_epc_func_no = func_no;
+		epf->sec_epc = epc;
+		list = &epf->sec_epc_list;
+	}
 
+	list_add_tail(list, &epc->pci_epf);
 ret:
 	mutex_unlock(&epc->lock);
 
@@ -627,14 +643,26 @@ EXPORT_SYMBOL_GPL(pci_epc_add_epf);
  *
  * Invoke to remove PCI endpoint function from the endpoint controller.
  */
-void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf)
+void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
+			enum pci_epc_interface_type type)
 {
+	struct list_head *list;
+	u32 func_no = 0;
+
 	if (!epc || IS_ERR(epc) || !epf)
 		return;
 
+	if (type == PRIMARY_INTERFACE) {
+		func_no = epf->func_no;
+		list = &epf->list;
+	} else {
+		func_no = epf->sec_epc_func_no;
+		list = &epf->sec_epc_list;
+	}
+
 	mutex_lock(&epc->lock);
-	clear_bit(epf->func_no, &epc->function_num_map);
-	list_del(&epf->list);
+	clear_bit(func_no, &epc->function_num_map);
+	list_del(list);
 	epf->epc = NULL;
 	mutex_unlock(&epc->lock);
 }
diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index f463eedcc3ad..97ddb86faac5 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -73,24 +73,37 @@ EXPORT_SYMBOL_GPL(pci_epf_bind);
  * pci_epf_free_space() - free the allocated PCI EPF register space
  * @addr: the virtual address of the PCI EPF register space
  * @bar: the BAR number corresponding to the register space
+ * @type: Identifies if the allocated space is for primary EPC or secondary EPC
  *
  * Invoke to free the allocated PCI EPF register space.
  */
-void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar)
+void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
+			enum pci_epc_interface_type type)
 {
 	struct device *dev = epf->epc->dev.parent;
+	struct pci_epf_bar *epf_bar;
+	struct pci_epc *epc;
 
 	if (!addr)
 		return;
 
-	dma_free_coherent(dev, epf->bar[bar].size, addr,
-			  epf->bar[bar].phys_addr);
+	if (type == PRIMARY_INTERFACE) {
+		epc = epf->epc;
+		epf_bar = epf->bar;
+	} else {
+		epc = epf->sec_epc;
+		epf_bar = epf->sec_epc_bar;
+	}
+
+	dev = epc->dev.parent;
+	dma_free_coherent(dev, epf_bar[bar].size, addr,
+			  epf_bar[bar].phys_addr);
 
-	epf->bar[bar].phys_addr = 0;
-	epf->bar[bar].addr = NULL;
-	epf->bar[bar].size = 0;
-	epf->bar[bar].barno = 0;
-	epf->bar[bar].flags = 0;
+	epf_bar[bar].phys_addr = 0;
+	epf_bar[bar].addr = NULL;
+	epf_bar[bar].size = 0;
+	epf_bar[bar].barno = 0;
+	epf_bar[bar].flags = 0;
 }
 EXPORT_SYMBOL_GPL(pci_epf_free_space);
 
@@ -99,15 +112,18 @@ EXPORT_SYMBOL_GPL(pci_epf_free_space);
  * @size: the size of the memory that has to be allocated
  * @bar: the BAR number corresponding to the allocated register space
  * @align: alignment size for the allocation region
+ * @type: Identifies if the allocation is for primary EPC or secondary EPC
  *
  * Invoke to allocate memory for the PCI EPF register space.
  */
 void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
-			  size_t align)
+			  size_t align, enum pci_epc_interface_type type)
 {
-	void *space;
-	struct device *dev = epf->epc->dev.parent;
+	struct pci_epf_bar *epf_bar;
 	dma_addr_t phys_addr;
+	struct pci_epc *epc;
+	struct device *dev;
+	void *space;
 
 	if (size < 128)
 		size = 128;
@@ -117,17 +133,26 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
 	else
 		size = roundup_pow_of_two(size);
 
+	if (type == PRIMARY_INTERFACE) {
+		epc = epf->epc;
+		epf_bar = epf->bar;
+	} else {
+		epc = epf->sec_epc;
+		epf_bar = epf->sec_epc_bar;
+	}
+
+	dev = epc->dev.parent;
 	space = dma_alloc_coherent(dev, size, &phys_addr, GFP_KERNEL);
 	if (!space) {
 		dev_err(dev, "failed to allocate mem space\n");
 		return NULL;
 	}
 
-	epf->bar[bar].phys_addr = phys_addr;
-	epf->bar[bar].addr = space;
-	epf->bar[bar].size = size;
-	epf->bar[bar].barno = bar;
-	epf->bar[bar].flags |= upper_32_bits(size) ?
+	epf_bar[bar].phys_addr = phys_addr;
+	epf_bar[bar].addr = space;
+	epf_bar[bar].size = size;
+	epf_bar[bar].barno = bar;
+	epf_bar[bar].flags |= upper_32_bits(size) ?
 				PCI_BASE_ADDRESS_MEM_TYPE_64 :
 				PCI_BASE_ADDRESS_MEM_TYPE_32;
 
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 490a9077df52..e7614dda4e0e 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -13,6 +13,12 @@
 
 struct pci_epc;
 
+enum pci_epc_interface_type {
+	UNKNOWN_INTERFACE = -1,
+	PRIMARY_INTERFACE,
+	SECONDARY_INTERFACE,
+};
+
 enum pci_epc_irq_type {
 	PCI_EPC_IRQ_UNKNOWN,
 	PCI_EPC_IRQ_LEGACY,
@@ -20,6 +26,19 @@ enum pci_epc_irq_type {
 	PCI_EPC_IRQ_MSIX,
 };
 
+static inline const char *
+pci_epc_interface_string(enum pci_epc_interface_type type)
+{
+	switch (type) {
+	case PRIMARY_INTERFACE:
+		return "primary";
+	case SECONDARY_INTERFACE:
+		return "secondary";
+	default:
+		return "UNKNOWN interface";
+	}
+}
+
 /**
  * struct pci_epc_ops - set of function pointers for performing EPC operations
  * @write_header: ops to populate configuration space header
@@ -175,10 +194,12 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
 		 struct module *owner);
 void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc);
 void pci_epc_destroy(struct pci_epc *epc);
-int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf);
+int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
+		    enum pci_epc_interface_type type);
 void pci_epc_linkup(struct pci_epc *epc);
 void pci_epc_init_notify(struct pci_epc *epc);
-void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf);
+void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
+			enum pci_epc_interface_type type);
 int pci_epc_write_header(struct pci_epc *epc, u8 func_no,
 			 struct pci_epf_header *hdr);
 int pci_epc_set_bar(struct pci_epc *epc, u8 func_no,
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 9bd89f1be1c3..581fe121d670 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -15,6 +15,7 @@
 #include <linux/pci.h>
 
 struct pci_epf;
+enum pci_epc_interface_type;
 
 enum pci_notify_event {
 	CORE_INIT,
@@ -121,6 +122,11 @@ struct pci_epf_bar {
  * @list: to add pci_epf as a list of PCI endpoint functions to pci_epc
  * @nb: notifier block to notify EPF of any EPC events (like linkup)
  * @lock: mutex to protect pci_epf_ops
+ * @sec_epc: the secondary EPC device to which this EPF device is bound
+ * @sec_epc_list: to add pci_epf as list of PCI endpoint functions to secondary
+ *   EPC device
+ * @sec_epc_bar: represents the BAR of EPF device associated with secondary EPC
+ * @sec_epc_func_no: unique (physical) function number within the secondary EPC
  */
 struct pci_epf {
 	struct device		dev;
@@ -138,6 +144,12 @@ struct pci_epf {
 	struct notifier_block   nb;
 	/* mutex to protect against concurrent access of pci_epf_ops */
 	struct mutex		lock;
+
+	/* Below members are to attach secondary EPC to an endpoint function */
+	struct pci_epc		*sec_epc;
+	struct list_head	sec_epc_list;
+	struct pci_epf_bar	sec_epc_bar[6];
+	u8			sec_epc_func_no;
 };
 
 /**
@@ -177,8 +189,9 @@ int __pci_epf_register_driver(struct pci_epf_driver *driver,
 			      struct module *owner);
 void pci_epf_unregister_driver(struct pci_epf_driver *driver);
 void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
-			  size_t align);
-void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar);
+			  size_t align, enum pci_epc_interface_type type);
+void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
+			enum pci_epc_interface_type type);
 int pci_epf_bind(struct pci_epf *epf);
 void pci_epf_unbind(struct pci_epf *epf);
 #endif /* __LINUX_PCI_EPF_H */
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 13/19] PCI: endpoint: Add pci_epc_ops to map MSI irq
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (11 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 12/19] PCI: endpoint: Add support to associate secondary EPC with EPF Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 14/19] PCI: cadence: Implement ->msi_map_irq() ops Kishon Vijay Abraham I
                   ` (6 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add pci_epc_ops to map physical address to MSI address and return MSI
data. The physical address is an address in the outbound region. This is
required to implement doorbell functionality of NTB (non transparent
bridge) wherein EPC on either side of the interface (primary and
secondary) can directly write to the physical address (in outbound
region) of the other interface to ring doorbell using MSI.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/pci-epc-core.c | 40 +++++++++++++++++++++++++++++
 include/linux/pci-epc.h             |  7 +++++
 2 files changed, 47 insertions(+)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index bd8f372c506f..3f481a12d43d 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -314,6 +314,46 @@ int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no,
 }
 EXPORT_SYMBOL_GPL(pci_epc_raise_irq);
 
+/**
+ * pci_epc_map_msi_irq() - Map physical address to MSI address and return
+ *                         MSI data
+ * @epc: the EPC device which has the MSI capability
+ * @func_no: the physical endpoint function number in the EPC device
+ * @vfunc_no: the virtual endpoint function number in the physical function
+ * @phys_addr: the physical address of the outbound region
+ * @interrupt_num: the MSI interrupt number
+ * @entry_size: Size of Outbound address region for each interrupt
+ * @msi_data: the data that should be written in order to raise MSI interrupt
+ *            with interrupt number as 'interrupt num'
+ *
+ * Invoke to map physical address to MSI address and return MSI data. The
+ * physical address should be an address in the outbound region. This is
+ * required to implement doorbell functionality of NTB wherein EPC on either
+ * side of the interface (primary and secondary) can directly write to the
+ * physical address (in outbound region) of the other interface to ring
+ * doorbell.
+ */
+int pci_epc_map_msi_irq(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+			phys_addr_t phys_addr, u8 interrupt_num, u32 entry_size,
+			u32 *msi_data)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(epc))
+		return -EINVAL;
+
+	if (!epc->ops->map_msi_irq)
+		return -EINVAL;
+
+	mutex_lock(&epc->lock);
+	ret = epc->ops->map_msi_irq(epc, func_no, vfunc_no, phys_addr,
+				    interrupt_num, entry_size, msi_data);
+	mutex_unlock(&epc->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pci_epc_map_msi_irq);
+
 /**
  * pci_epc_get_msi() - get the number of MSI interrupt numbers allocated
  * @epc: the EPC device to which MSI interrupts was requested
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index e7614dda4e0e..59cd4c967329 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -55,6 +55,7 @@ pci_epc_interface_string(enum pci_epc_interface_type type)
  * @get_msix: ops to get the number of MSI-X interrupts allocated by the RC
  *	     from the MSI-X capability register
  * @raise_irq: ops to raise a legacy, MSI or MSI-X interrupt
+ * @map_msi_irq: ops to map physical address to MSI address and return MSI data
  * @start: ops to start the PCI link
  * @stop: ops to stop the PCI link
  * @owner: the module owner containing the ops
@@ -77,6 +78,9 @@ struct pci_epc_ops {
 	int	(*get_msix)(struct pci_epc *epc, u8 func_no);
 	int	(*raise_irq)(struct pci_epc *epc, u8 func_no,
 			     enum pci_epc_irq_type type, u16 interrupt_num);
+	int	(*map_msi_irq)(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+			       phys_addr_t phys_addr, u8 interrupt_num,
+			       u32 entry_size, u32 *msi_data);
 	int	(*start)(struct pci_epc *epc);
 	void	(*stop)(struct pci_epc *epc);
 	const struct pci_epc_features* (*get_features)(struct pci_epc *epc,
@@ -216,6 +220,9 @@ int pci_epc_get_msi(struct pci_epc *epc, u8 func_no);
 int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts,
 		     enum pci_barno, u32 offset);
 int pci_epc_get_msix(struct pci_epc *epc, u8 func_no);
+int pci_epc_map_msi_irq(struct pci_epc *epc, u8 func_no,
+			phys_addr_t phys_addr, u8 interrupt_num,
+			u32 entry_size, u32 *msi_data);
 int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no,
 		      enum pci_epc_irq_type type, u16 interrupt_num);
 int pci_epc_start(struct pci_epc *epc);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 14/19] PCI: cadence: Implement ->msi_map_irq() ops
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (12 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 13/19] PCI: endpoint: Add pci_epc_ops to map MSI irq Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 15/19] PCI: endpoint: Add EP function driver to provide NTB functionality Kishon Vijay Abraham I
                   ` (5 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Implement ->msi_map_irq() ops in order to map physical address to
MSI address and return MSI data.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 .../pci/controller/cadence/pcie-cadence-ep.c  | 50 +++++++++++++++++++
 drivers/pci/endpoint/pci-epc-core.c           |  7 ++-
 include/linux/pci-epc.h                       |  2 +-
 3 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
index e6588a0cd705..74d36fb9ea5d 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
@@ -380,6 +380,54 @@ static int cdns_pcie_ep_send_msi_irq(struct cdns_pcie_ep *ep, u8 fn,
 	return 0;
 }
 
+static int cdns_pcie_ep_map_msi_irq(struct pci_epc *epc, u8 fn,
+				    phys_addr_t addr, u8 interrupt_num,
+				    u32 entry_size, u32 *msi_data)
+{
+	struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+	u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
+	struct cdns_pcie *pcie = &ep->pcie;
+	u16 flags, mme, data, data_mask;
+	u8 msi_count;
+	u64 pci_addr;
+	int ret;
+	int i;
+
+	/* Check whether the MSI feature has been enabled by the PCI host. */
+	flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
+	if (!(flags & PCI_MSI_FLAGS_ENABLE))
+		return -EINVAL;
+
+	/* Get the number of enabled MSIs */
+	mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4;
+	msi_count = 1 << mme;
+	if (!interrupt_num || interrupt_num > msi_count)
+		return -EINVAL;
+
+	/* Compute the data value to be written. */
+	data_mask = msi_count - 1;
+	data = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_DATA_64);
+	data = data & ~data_mask;
+
+	/* Get the PCI address where to write the data into. */
+	pci_addr = cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_HI);
+	pci_addr <<= 32;
+	pci_addr |= cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_LO);
+	pci_addr &= GENMASK_ULL(63, 2);
+
+	for (i = 0; i < interrupt_num; i++) {
+		ret = cdns_pcie_ep_map_addr(epc, fn, addr, pci_addr,
+					    entry_size);
+		if (ret)
+			return ret;
+		addr = addr + entry_size;
+	}
+
+	*msi_data = data;
+
+	return 0;
+}
+
 static int cdns_pcie_ep_send_msix_irq(struct cdns_pcie_ep *ep, u8 fn,
 				      u16 interrupt_num)
 {
@@ -480,6 +528,7 @@ static const struct pci_epc_features cdns_pcie_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
 	.msix_capable = true,
+	.align = 256,
 };
 
 static const struct pci_epc_features*
@@ -499,6 +548,7 @@ static const struct pci_epc_ops cdns_pcie_epc_ops = {
 	.set_msix	= cdns_pcie_ep_set_msix,
 	.get_msix	= cdns_pcie_ep_get_msix,
 	.raise_irq	= cdns_pcie_ep_raise_irq,
+	.map_msi_irq	= cdns_pcie_ep_map_msi_irq,
 	.start		= cdns_pcie_ep_start,
 	.get_features	= cdns_pcie_ep_get_features,
 };
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 3f481a12d43d..ab5da996953e 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -319,7 +319,6 @@ EXPORT_SYMBOL_GPL(pci_epc_raise_irq);
  *                         MSI data
  * @epc: the EPC device which has the MSI capability
  * @func_no: the physical endpoint function number in the EPC device
- * @vfunc_no: the virtual endpoint function number in the physical function
  * @phys_addr: the physical address of the outbound region
  * @interrupt_num: the MSI interrupt number
  * @entry_size: Size of Outbound address region for each interrupt
@@ -333,7 +332,7 @@ EXPORT_SYMBOL_GPL(pci_epc_raise_irq);
  * physical address (in outbound region) of the other interface to ring
  * doorbell.
  */
-int pci_epc_map_msi_irq(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+int pci_epc_map_msi_irq(struct pci_epc *epc, u8 func_no,
 			phys_addr_t phys_addr, u8 interrupt_num, u32 entry_size,
 			u32 *msi_data)
 {
@@ -346,8 +345,8 @@ int pci_epc_map_msi_irq(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 		return -EINVAL;
 
 	mutex_lock(&epc->lock);
-	ret = epc->ops->map_msi_irq(epc, func_no, vfunc_no, phys_addr,
-				    interrupt_num, entry_size, msi_data);
+	ret = epc->ops->map_msi_irq(epc, func_no, phys_addr, interrupt_num,
+				    entry_size, msi_data);
 	mutex_unlock(&epc->lock);
 
 	return ret;
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 59cd4c967329..bb00f107c0dc 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -78,7 +78,7 @@ struct pci_epc_ops {
 	int	(*get_msix)(struct pci_epc *epc, u8 func_no);
 	int	(*raise_irq)(struct pci_epc *epc, u8 func_no,
 			     enum pci_epc_irq_type type, u16 interrupt_num);
-	int	(*map_msi_irq)(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+	int	(*map_msi_irq)(struct pci_epc *epc, u8 func_no,
 			       phys_addr_t phys_addr, u8 interrupt_num,
 			       u32 entry_size, u32 *msi_data);
 	int	(*start)(struct pci_epc *epc);
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 15/19] PCI: endpoint: Add EP function driver to provide NTB functionality
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (13 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 14/19] PCI: cadence: Implement ->msi_map_irq() ops Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 16/19] PCI: Add TI J721E device to pci ids Kishon Vijay Abraham I
                   ` (4 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add a new endpoint function driver to provide NTB functionality
using multiple PCIe endpoint instances.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/functions/Kconfig       |   12 +
 drivers/pci/endpoint/functions/Makefile      |    1 +
 drivers/pci/endpoint/functions/pci-epf-ntb.c | 2038 ++++++++++++++++++
 3 files changed, 2051 insertions(+)
 create mode 100644 drivers/pci/endpoint/functions/pci-epf-ntb.c

diff --git a/drivers/pci/endpoint/functions/Kconfig b/drivers/pci/endpoint/functions/Kconfig
index 8820d0f7ec77..55ac7bb2d469 100644
--- a/drivers/pci/endpoint/functions/Kconfig
+++ b/drivers/pci/endpoint/functions/Kconfig
@@ -12,3 +12,15 @@ config PCI_EPF_TEST
 	   for PCI Endpoint.
 
 	   If in doubt, say "N" to disable Endpoint test driver.
+
+config PCI_EPF_NTB
+	tristate "PCI Endpoint NTB driver"
+	depends on PCI_ENDPOINT
+	help
+	   Select this configuration option to enable the NTB driver
+	   for PCI Endpoint. NTB driver implements NTB controller
+	   functionality using multiple PCIe endpoint instances. It
+	   can support NTB endpoint function devices created using
+	   device tree.
+
+	   If in doubt, say "N" to disable Endpoint NTB driver.
diff --git a/drivers/pci/endpoint/functions/Makefile b/drivers/pci/endpoint/functions/Makefile
index d6fafff080e2..96ab932a537a 100644
--- a/drivers/pci/endpoint/functions/Makefile
+++ b/drivers/pci/endpoint/functions/Makefile
@@ -4,3 +4,4 @@
 #
 
 obj-$(CONFIG_PCI_EPF_TEST)		+= pci-epf-test.o
+obj-$(CONFIG_PCI_EPF_NTB)		+= pci-epf-ntb.o
diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c
new file mode 100644
index 000000000000..0229ef456d7f
--- /dev/null
+++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c
@@ -0,0 +1,2038 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Endpoint Function Driver to implement Non-Transparent Bridge functionality
+ *
+ * Copyright (C) 2020 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+/*
+ *The PCI NTB function driver configures the SoC with multiple PCIe Endpoint(EP)
+ *controller instances (see diagram below) in such a way that transaction from
+ *one EP controller is routed to the other EP controller. Once PCI NTB function
+ *driver configures the SoC with multiple EP instances, HOST1 and HOST2 can
+ *communicate with each other using SoC as a bridge.
+ *
+ *   +-------------+                                   +-------------+
+ *   |             |                                   |             |
+ *   |    HOST1    |                                   |    HOST2    |
+ *   |             |                                   |             |
+ *   +------^------+                                   +------^------+
+ *          |                                                 |
+ *          |                                                 |
+ *+---------|-------------------------------------------------|---------+
+ *|  +------v------+                                   +------v------+  |
+ *|  |             |                                   |             |  |
+ *|  |     EP      |                                   |     EP      |  |
+ *|  | CONTROLLER1 |                                   | CONTROLLER2 |  |
+ *|  |             <----------------------------------->             |  |
+ *|  |             |                                   |             |  |
+ *|  |             |                                   |             |  |
+ *|  |             |  SoC With Multiple EP Instances   |             |  |
+ *|  |             |  (Configured using NTB Function)  |             |  |
+ *|  +-------------+                                   +-------------+  |
+ *+---------------------------------------------------------------------+
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+
+static struct workqueue_struct *kpcintb_workqueue;
+
+#define COMMAND_CONFIGURE_DOORBELL	1
+#define COMMAND_TEARDOWN_DOORBELL	2
+#define COMMAND_CONFIGURE_MW		3
+#define COMMAND_TEARDOWN_MW		4
+#define COMMAND_LINK_UP			5
+#define COMMAND_LINK_DOWN		6
+
+#define COMMAND_STATUS_OK		1
+#define COMMAND_STATUS_ERROR		2
+
+#define LINK_STATUS_UP			BIT(0)
+
+#define SPAD_COUNT			64
+#define DB_COUNT			4
+#define NTB_MW_OFFSET			2
+#define DB_COUNT_MASK			GENMASK(15, 0)
+#define MSIX_ENABLE			BIT(16)
+#define MAX_DB_COUNT			32
+#define MAX_MW				4
+
+enum epf_ntb_bar {
+	BAR_CONFIG,
+	BAR_PEER_SPAD,
+	BAR_DB_MW1,
+	BAR_MW2,
+	BAR_MW3,
+	BAR_MW4,
+};
+
+struct epf_ntb {
+	u32 num_mws;
+	u32 db_count;
+	u64 *mws_size;
+	u32 spad_count;
+	struct pci_epf *epf;
+	struct epf_ntb_epc *epc[2];
+};
+
+struct epf_ntb_epc {
+	u8 func_no;
+	bool linkup;
+	bool is_msix;
+	int msix_bar;
+	u32 spad_size;
+	struct pci_epc *epc;
+	struct epf_ntb *epf_ntb;
+	void __iomem *mw_addr[6];
+	size_t msix_table_offset;
+	struct epf_ntb_ctrl *reg;
+	struct pci_epf_bar *epf_bar;
+	enum pci_barno epf_ntb_bar[6];
+	struct delayed_work cmd_handler;
+	enum pci_epc_interface_type type;
+	const struct pci_epc_features *epc_features;
+};
+
+struct epf_ntb_ctrl {
+	u32	command;
+	u32	argument;
+	u16	command_status;
+	u16	link_status;
+	u32	topology;
+	u64	addr;
+	u64	size;
+	u32	num_mws;
+	u32	mw1_offset;
+	u32	spad_offset;
+	u32	spad_count;
+	u32	db_entry_size;
+	u32	db_data[MAX_DB_COUNT];
+} __packed;
+
+static struct pci_epf_header epf_ntb_header = {
+	.vendorid	= PCI_ANY_ID,
+	.deviceid	= PCI_ANY_ID,
+	.baseclass_code	= PCI_BASE_CLASS_MEMORY,
+	.interrupt_pin	= PCI_INTERRUPT_INTA,
+};
+
+/**
+ * epf_ntb_link_up() - Raise link_up interrupt to both the hosts
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @link_up: true or false indicating Link is UP or Down
+ *
+ * Once NTB function in HOST1 and the NTB function in HOST2 invoke
+ * ntb_link_enable(), this NTB function driver will trigger a link event to
+ * the NTB client in both the hosts.
+ */
+static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
+{
+	enum pci_epc_interface_type type;
+	enum pci_epc_irq_type irq_type;
+	struct epf_ntb_epc *ntb_epc;
+	struct epf_ntb_ctrl *ctrl;
+	bool is_msix;
+	u8 func_no;
+	int ret;
+
+	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+		ntb_epc = ntb->epc[type];
+		func_no = ntb_epc->func_no;
+		is_msix = ntb_epc->is_msix;
+		ctrl = ntb_epc->reg;
+		if (link_up)
+			ctrl->link_status |= LINK_STATUS_UP;
+		else
+			ctrl->link_status &= ~LINK_STATUS_UP;
+		irq_type = is_msix ? PCI_EPC_IRQ_MSIX : PCI_EPC_IRQ_MSI;
+		ret = pci_epc_raise_irq(ntb_epc->epc, func_no, irq_type,
+					1);
+		if (ret < 0) {
+			WARN(1, "%s intf: Failed to raise Link Up IRQ\n",
+			     pci_epc_interface_string(type));
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * epf_ntb_configure_mw() - Configure the Outbound Address Space for one host
+ *   to access the memory window of other host
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @mw: Index of the memory window (either 0, 1, 2 or 3)
+ *
+ *+-----------------+    +----->+----------------+-----------+-----------------+
+ *|       BAR0      |    |      |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
+ *+-----------------+    |      +----------------+           +-----------------+
+ *|       BAR1      |    |      |   Doorbell 2   +---------+ |                 |
+ *+-----------------+----+      +----------------+         | |                 |
+ *|       BAR2      |           |   Doorbell 3   +-------+ | +-----------------+
+ *+-----------------+----+      +----------------+       | +-> MSI|X ADDRESS 2 |
+ *|       BAR3      |    |      |   Doorbell 4   +-----+ |   +-----------------+
+ *+-----------------+    |      |----------------+     | |   |                 |
+ *|       BAR4      |    |      |                |     | |   +-----------------+
+ *+-----------------+    |      |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
+ *|       BAR5      |    |      |                |   | |     +-----------------+
+ *+-----------------+    +----->-----------------+   | |     |                 |
+ *  EP CONTROLLER 1             |                |   | |     +-----------------+
+ *                              |                |   | +---->+ MSI|X ADDRESS 4 |
+ *                              +----------------+   |       +-----------------+
+ *                     (A)       EP CONTROLLER 2     |       |                 |
+ *                                 (OB SPACE)        |       |                 |
+ *                                                   +------->      MW1        |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                   (B)     +-----------------+
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           +-----------------+
+ *                                                           PCI Address Space
+ *                                                           (Managed by HOST2)
+ *
+ * This function performs stage (B) in the above diagram (see MW1) i.e map OB
+ * address space of memory window to PCI address space.
+ *
+ * This operation requires 3 parameters
+ *  1) Address in the outbound address space
+ *  2) Address in the PCIe Address space
+ *  3) Size of the address region that is requested to be mapped
+ *
+ * The address in the outbound address space (for MW1, MW2, MW3 and MW4) is
+ * stored in epf_bar corresponding to BAR_DB_MW1 for MW1 and BAR_MW2, BAR_MW3
+ * BAR_MW4 for rest of the BARs of epf_ntb_epc that is connected to HOST1. This
+ * is populated in epf_ntb_alloc_peer_mem() in this driver.
+ *
+ * The address and size of the PCIe address region that has to be mapped would
+ * be provided by HOST2 in ctrl->addr and ctrl->size of epf_ntb_epc that is
+ * connected to HOST2.
+ *
+ * Please note Memory window1 (MW1) and Doorbell registers together will be
+ * mapped to a single BAR (BAR2) above for 32-bit BARs. The exact BAR that's
+ * used for Memory window (MW) can be obtained from epf_ntb_bar[BAR_DB_MW1],
+ * epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2].
+ */
+static int
+epf_ntb_configure_mw(struct epf_ntb *ntb, enum pci_epc_interface_type type,
+		     u32 mw)
+{
+	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+	struct pci_epf_bar *peer_epf_bar;
+	enum pci_barno peer_barno;
+	struct epf_ntb_ctrl *ctrl;
+	phys_addr_t phys_addr;
+	struct pci_epc *epc;
+	u64 addr, size;
+	int ret = 0;
+	u8 func_no;
+
+	ntb_epc = ntb->epc[type];
+	epc = ntb_epc->epc;
+
+	peer_ntb_epc = ntb->epc[!type];
+	peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
+	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+
+	phys_addr = peer_epf_bar->phys_addr;
+	ctrl = ntb_epc->reg;
+	addr = ctrl->addr;
+	size = ctrl->size;
+	if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
+		phys_addr += ctrl->mw1_offset;
+
+	if (size > ntb->mws_size[mw]) {
+		WARN(1, "%s intf: MW: %d Req Sz:%llxx > Supported Sz:%llx\n",
+		     pci_epc_interface_string(type), mw, size,
+		     ntb->mws_size[mw]);
+		ret = -EINVAL;
+		goto err_invalid_size;
+	}
+
+	func_no = ntb_epc->func_no;
+
+	ret = pci_epc_map_addr(epc, func_no, phys_addr, addr, size);
+	WARN(ret < 0, "%s intf: Failed to map memory window %d address\n",
+	     pci_epc_interface_string(type), mw);
+
+err_invalid_size:
+
+	return ret;
+}
+
+/**
+ * epf_ntb_teardown_mw() - Teardown the configured OB ATU
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @mw: Index of the memory window (either 0, 1, 2 or 3)
+ *
+ * Teardown the configured OB ATU configured in epf_ntb_configure_mw() using
+ * pci_epc_unmap_addr()
+ */
+static void
+epf_ntb_teardown_mw(struct epf_ntb *ntb, enum pci_epc_interface_type type,
+		    u32 mw)
+{
+	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+	struct pci_epf_bar *peer_epf_bar;
+	enum pci_barno peer_barno;
+	struct epf_ntb_ctrl *ctrl;
+	phys_addr_t phys_addr;
+	struct pci_epc *epc;
+	u8 func_no;
+
+	ntb_epc = ntb->epc[type];
+	epc = ntb_epc->epc;
+
+	peer_ntb_epc = ntb->epc[!type];
+	peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
+	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+
+	phys_addr = peer_epf_bar->phys_addr;
+	ctrl = ntb_epc->reg;
+	if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
+		phys_addr += ctrl->mw1_offset;
+	func_no = ntb_epc->func_no;
+
+	pci_epc_unmap_addr(epc, func_no, phys_addr);
+}
+
+/**
+ * epf_ntb_configure_msi() - Map OB address space to MSI address
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @db_count: Number of doorbell interrupts to map
+ *
+ *+-----------------+    +----->+----------------+-----------+-----------------+
+ *|       BAR0      |    |      |   Doorbell 1   +---+------->   MSI ADDRESS   |
+ *+-----------------+    |      +----------------+   |       +-----------------+
+ *|       BAR1      |    |      |   Doorbell 2   +---+       |                 |
+ *+-----------------+----+      +----------------+   |       |                 |
+ *|       BAR2      |           |   Doorbell 3   +---+       |                 |
+ *+-----------------+----+      +----------------+   |       |                 |
+ *|       BAR3      |    |      |   Doorbell 4   +---+       |                 |
+ *+-----------------+    |      |----------------+           |                 |
+ *|       BAR4      |    |      |                |           |                 |
+ *+-----------------+    |      |      MW1       |           |                 |
+ *|       BAR5      |    |      |                |           |                 |
+ *+-----------------+    +----->-----------------+           |                 |
+ *  EP CONTROLLER 1             |                |           |                 |
+ *                              |                |           |                 |
+ *                              +----------------+           +-----------------+
+ *                     (A)       EP CONTROLLER 2             |                 |
+ *                                 (OB SPACE)                |                 |
+ *                                                           |      MW1        |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                   (B)     +-----------------+
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           +-----------------+
+ *                                                           PCI Address Space
+ *                                                           (Managed by HOST2)
+ *
+ *
+ * This function performs stage (B) in the above diagram (see Doorbell 1,
+ * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
+ * doorbell to MSI address in PCI address space.
+ *
+ * This operation requires 3 parameters
+ *  1) Address reserved for doorbell in the outbound address space
+ *  2) MSI-X address in the PCIe Address space
+ *  3) Number of MSI-X interrupts that has to be configured
+ *
+ * The address in the outbound address space (for the Doorbell) is stored in
+ * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
+ * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
+ * with address for MW1.
+ *
+ * pci_epc_map_msi_irq() takes the MSI address from MSI capability register
+ * and maps the OB address (obtained in epf_ntb_alloc_peer_mem()) to the MSI
+ * address.
+ *
+ * epf_ntb_configure_msi() also stores the MSI data to raise each interrupt
+ * in db_data of the peer's control region. This helps the peer to raise
+ * doorbell of the other host by writing db_data to the BAR corresponding to
+ * BAR_DB_MW1.
+ */
+static int
+epf_ntb_configure_msi(struct epf_ntb *ntb, enum pci_epc_interface_type type,
+		      u16 db_count)
+{
+	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+	struct pci_epf_bar *peer_epf_bar;
+	struct epf_ntb_ctrl *peer_ctrl;
+	u32 db_entry_size, db_data;
+	enum pci_barno peer_barno;
+	phys_addr_t phys_addr;
+	struct pci_epc *epc;
+	u8 func_no;
+	int ret, i;
+
+	ntb_epc = ntb->epc[type];
+	epc = ntb_epc->epc;
+
+	peer_ntb_epc = ntb->epc[!type];
+	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
+	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+	peer_ctrl = peer_ntb_epc->reg;
+	db_entry_size = peer_ctrl->db_entry_size;
+
+	phys_addr = peer_epf_bar->phys_addr;
+	func_no = ntb_epc->func_no;
+
+	ret = pci_epc_map_msi_irq(epc, func_no, phys_addr, db_count,
+				  db_entry_size, &db_data);
+	if (ret < 0) {
+		WARN(1, "%s intf: Failed to map MSI IRQ\n",
+		     pci_epc_interface_string(type));
+		return ret;
+	}
+
+	for (i = 0; i < db_count; i++)
+		peer_ctrl->db_data[i] = db_data | i;
+
+	return 0;
+}
+
+/**
+ * epf_ntb_configure_msix() - Map OB address space to MSI-X address
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @db_count: Number of doorbell interrupts to map
+ *
+ *+-----------------+    +----->+----------------+-----------+-----------------+
+ *|       BAR0      |    |      |   Doorbell 1   +-----------> MSI-X ADDRESS 1 |
+ *+-----------------+    |      +----------------+           +-----------------+
+ *|       BAR1      |    |      |   Doorbell 2   +---------+ |                 |
+ *+-----------------+----+      +----------------+         | |                 |
+ *|       BAR2      |           |   Doorbell 3   +-------+ | +-----------------+
+ *+-----------------+----+      +----------------+       | +-> MSI-X ADDRESS 2 |
+ *|       BAR3      |    |      |   Doorbell 4   +-----+ |   +-----------------+
+ *+-----------------+    |      |----------------+     | |   |                 |
+ *|       BAR4      |    |      |                |     | |   +-----------------+
+ *+-----------------+    |      |      MW1       +     | +-->+ MSI-X ADDRESS 3||
+ *|       BAR5      |    |      |                |     |     +-----------------+
+ *+-----------------+    +----->-----------------+     |     |                 |
+ *  EP CONTROLLER 1             |                |     |     +-----------------+
+ *                              |                |     +---->+ MSI-X ADDRESS 4 |
+ *                              +----------------+           +-----------------+
+ *                     (A)       EP CONTROLLER 2             |                 |
+ *                                 (OB SPACE)                |                 |
+ *                                                           |      MW1        |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                   (B)     +-----------------+
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           +-----------------+
+ *                                                           PCI Address Space
+ *                                                           (Managed by HOST2)
+ *
+ * This function performs stage (B) in the above diagram (see Doorbell 1,
+ * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
+ * doorbell to MSI-X address in PCI address space.
+ *
+ * This operation requires 3 parameters
+ *  1) Address reserved for doorbell in the outbound address space
+ *  2) MSI-X address in the PCIe Address space
+ *  3) Number of MSI-X interrupts that has to be configured
+ *
+ * The address in the outbound address space (for the Doorbell) is stored in
+ * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
+ * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
+ * with address for MW1.
+ * The MSI-X address is in the MSI-X table of EP CONTROLLER 2 and
+ * the count of doorbell is in ctrl->argument of epf_ntb_epc that is connected
+ * to HOST2. MSI-X table is stored memory mapped to ntb_epc->msix_bar and the
+ * offset is in ntb_epc->msix_table_offset. From this epf_ntb_configure_msix()
+ * gets the MSI-X address and MSI-X data
+ *
+ * epf_ntb_configure_msix() also stores the MSI-X data to raise each interrupt
+ * in db_data of the peer's control region. This helps the peer to raise
+ * doorbell of the other host by writing db_data to the BAR corresponding to
+ * BAR_DB_MW1.
+ */
+static int epf_ntb_configure_msix(struct epf_ntb *ntb,
+				  enum pci_epc_interface_type type,
+				  u16 db_count)
+{
+	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+	struct pci_epf_bar *peer_epf_bar, *epf_bar;
+	struct pci_epf_msix_tbl *msix_tbl;
+	struct epf_ntb_ctrl *peer_ctrl;
+	u32 db_entry_size, msg_data;
+	enum pci_barno peer_barno;
+	phys_addr_t phys_addr;
+	struct pci_epc *epc;
+	u64 msg_addr;
+	u8 func_no;
+	int ret, i;
+
+	ntb_epc = ntb->epc[type];
+	epc = ntb_epc->epc;
+
+	epf_bar = &ntb_epc->epf_bar[ntb_epc->msix_bar];
+	msix_tbl = epf_bar->addr + ntb_epc->msix_table_offset;
+
+	peer_ntb_epc = ntb->epc[!type];
+	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
+	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+	phys_addr = peer_epf_bar->phys_addr;
+	peer_ctrl = peer_ntb_epc->reg;
+
+	func_no = ntb_epc->func_no;
+	db_entry_size = peer_ctrl->db_entry_size;
+
+	for (i = 0; i < db_count; i++) {
+		msg_addr = msix_tbl[i].msg_addr;
+		msg_data = msix_tbl[i].msg_data;
+		ret = pci_epc_map_addr(epc, func_no, phys_addr, msg_addr,
+				       db_entry_size);
+		if (ret)
+			return ret;
+		phys_addr = phys_addr + db_entry_size;
+		peer_ctrl->db_data[i] = msg_data;
+	}
+	ntb_epc->is_msix = true;
+
+	return 0;
+}
+
+/**
+ * epf_ntb_configure_db() - Configure the Outbound Address Space for one host
+ *   to ring the doorbell of other host
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ * @db_count: Count of the number of doorbells that has to be configured
+ * @msix: Indicates whether MSI-X or MSI should be used
+ *
+ * Invokes epf_ntb_configure_msix() or epf_ntb_configure_msi() required for
+ * one HOST to ring the doorbell of other HOST.
+ */
+static int
+epf_ntb_configure_db(struct epf_ntb *ntb, enum pci_epc_interface_type type,
+		     u16 db_count, bool msix)
+{
+	int ret;
+
+	if (db_count > MAX_DB_COUNT)
+		return -EINVAL;
+
+	if (msix)
+		ret = epf_ntb_configure_msix(ntb, type, db_count);
+	else
+		ret = epf_ntb_configure_msi(ntb, type, db_count);
+
+	WARN(ret < 0, "%s intf: Failed to configure DB\n",
+	     pci_epc_interface_string(type));
+
+	return ret;
+}
+
+/**
+ * epf_ntb_teardown_db() - Unmap address in OB address space to MSI/MSI-X
+ *   address
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Invoke pci_epc_unmap_addr() to unmap OB address to MSI/MSI-X address.
+ */
+static void
+epf_ntb_teardown_db(struct epf_ntb *ntb, enum pci_epc_interface_type type)
+{
+	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+	struct pci_epf_bar *peer_epf_bar;
+	enum pci_barno peer_barno;
+	phys_addr_t phys_addr;
+	struct pci_epc *epc;
+	u8 func_no;
+
+	ntb_epc = ntb->epc[type];
+	epc = ntb_epc->epc;
+
+	peer_ntb_epc = ntb->epc[!type];
+	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
+	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+	phys_addr = peer_epf_bar->phys_addr;
+	func_no = ntb_epc->func_no;
+
+	pci_epc_unmap_addr(epc, func_no, phys_addr);
+}
+
+/**
+ * epf_ntb_cmd_handler() - Handle commands provided by the NTB Host
+ * @work: work_struct for the two epf_ntb_epc (PRIMARY and SECONDARY)
+ *
+ * Workqueue function that gets invoked for the two epf_ntb_epc
+ * periodically (once every 5ms) to see if it has received any commands
+ * from NTB host. The host can send commands to configure doorbell or
+ * configure memory window or to update link status.
+ */
+static void epf_ntb_cmd_handler(struct work_struct *work)
+{
+	enum pci_epc_interface_type type;
+	struct epf_ntb_epc *ntb_epc;
+	struct epf_ntb_ctrl *ctrl;
+	u32 command, argument;
+	struct epf_ntb *ntb;
+	struct device *dev;
+	u16 db_count;
+	bool is_msix;
+	int ret;
+
+	ntb_epc = container_of(work, struct epf_ntb_epc, cmd_handler.work);
+	ctrl = ntb_epc->reg;
+	command = ctrl->command;
+	if (!command)
+		goto reset_handler;
+	argument = ctrl->argument;
+
+	ctrl->command = 0;
+	ctrl->argument = 0;
+
+	ctrl = ntb_epc->reg;
+	type = ntb_epc->type;
+	ntb = ntb_epc->epf_ntb;
+	dev = &ntb->epf->dev;
+
+	switch (command) {
+	case COMMAND_CONFIGURE_DOORBELL:
+		db_count = argument & DB_COUNT_MASK;
+		is_msix = argument & MSIX_ENABLE;
+		ret = epf_ntb_configure_db(ntb, type, db_count, is_msix);
+		if (ret < 0)
+			ctrl->command_status = COMMAND_STATUS_ERROR;
+		else
+			ctrl->command_status = COMMAND_STATUS_OK;
+		break;
+	case COMMAND_TEARDOWN_DOORBELL:
+		epf_ntb_teardown_db(ntb, type);
+		ctrl->command_status = COMMAND_STATUS_OK;
+		break;
+	case COMMAND_CONFIGURE_MW:
+		ret = epf_ntb_configure_mw(ntb, type, argument);
+		if (ret < 0)
+			ctrl->command_status = COMMAND_STATUS_ERROR;
+		else
+			ctrl->command_status = COMMAND_STATUS_OK;
+		break;
+	case COMMAND_TEARDOWN_MW:
+		epf_ntb_teardown_mw(ntb, type, argument);
+		ctrl->command_status = COMMAND_STATUS_OK;
+		break;
+	case COMMAND_LINK_UP:
+		ntb_epc->linkup = true;
+		if (ntb->epc[PRIMARY_INTERFACE]->linkup &&
+		    ntb->epc[SECONDARY_INTERFACE]->linkup) {
+			ret = epf_ntb_link_up(ntb, true);
+			if (ret < 0)
+				ctrl->command_status = COMMAND_STATUS_ERROR;
+			else
+				ctrl->command_status = COMMAND_STATUS_OK;
+			goto reset_handler;
+		}
+		ctrl->command_status = COMMAND_STATUS_OK;
+		break;
+	case COMMAND_LINK_DOWN:
+		ntb_epc->linkup = false;
+		ret = epf_ntb_link_up(ntb, false);
+		if (ret < 0)
+			ctrl->command_status = COMMAND_STATUS_ERROR;
+		else
+			ctrl->command_status = COMMAND_STATUS_OK;
+		break;
+	default:
+		dev_err(dev, "%s intf UNKNOWN command: %d\n",
+			pci_epc_interface_string(type), command);
+		break;
+	}
+
+reset_handler:
+	queue_delayed_work(kpcintb_workqueue, &ntb_epc->cmd_handler,
+			   msecs_to_jiffies(5));
+}
+
+/**
+ * epf_ntb_peer_spad_bar_clear() - Clears Peer Scratchpad BAR
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+        +-----------------+
+ *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
+ *+-----------------+----+   +------------------+<-------+-----------------+
+ *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
+ *+-----------------+    +-->+------------------+<-------+-----------------+
+ *|       BAR2      |            Local Memory            |       BAR2      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR3      |                                    |       BAR3      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR4      |                                    |       BAR4      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR5      |                                    |       BAR5      |
+ *+-----------------+                                    +-----------------+
+ *  EP CONTROLLER 1                                        EP CONTROLLER 2
+ *
+ * It clears BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
+ * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
+ * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
+ * This function can get the exact BAR used for peer scratchpad from
+ * epf_ntb_bar[BAR_PEER_SPAD].
+ *
+ * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
+ * gets the address of peer scratchpad from
+ * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG]
+ */
+static void epf_ntb_peer_spad_bar_clear(struct epf_ntb_epc *ntb_epc)
+{
+	struct pci_epf_bar *epf_bar;
+	enum pci_barno barno;
+	struct pci_epc *epc;
+	u8 func_no;
+
+	epc = ntb_epc->epc;
+	func_no = ntb_epc->func_no;
+	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
+	epf_bar = &ntb_epc->epf_bar[barno];
+	pci_epc_clear_bar(epc, func_no, epf_bar);
+}
+
+/**
+ * epf_ntb_peer_spad_bar_set() - Sets peer scratchpad BAR
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+        +-----------------+
+ *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
+ *+-----------------+----+   +------------------+<-------+-----------------+
+ *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
+ *+-----------------+    +-->+------------------+<-------+-----------------+
+ *|       BAR2      |            Local Memory            |       BAR2      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR3      |                                    |       BAR3      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR4      |                                    |       BAR4      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR5      |                                    |       BAR5      |
+ *+-----------------+                                    +-----------------+
+ *  EP CONTROLLER 1                                        EP CONTROLLER 2
+ *
+ * It sets BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
+ * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
+ * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
+ * This function can get the exact BAR used for peer scratchpad from
+ * epf_ntb_bar[BAR_PEER_SPAD].
+ *
+ * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
+ * gets the address of peer scratchpad from
+ * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG]
+ */
+static int
+epf_ntb_peer_spad_bar_set(struct epf_ntb *ntb, enum pci_epc_interface_type type)
+{
+	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+	struct pci_epf_bar *peer_epf_bar, *epf_bar;
+	enum pci_barno peer_barno, barno;
+	u32 peer_spad_offset;
+	struct pci_epc *epc;
+	struct device *dev;
+	u8 func_no;
+	int ret;
+
+	dev = &ntb->epf->dev;
+
+	peer_ntb_epc = ntb->epc[!type];
+	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_CONFIG];
+	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
+
+	ntb_epc = ntb->epc[type];
+	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
+	epf_bar = &ntb_epc->epf_bar[barno];
+	func_no = ntb_epc->func_no;
+	epc = ntb_epc->epc;
+
+	peer_spad_offset = peer_ntb_epc->reg->spad_offset;
+	epf_bar->phys_addr = peer_epf_bar->phys_addr + peer_spad_offset;
+	epf_bar->size = peer_ntb_epc->spad_size;
+	epf_bar->barno = barno;
+	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
+
+	ret = pci_epc_set_bar(ntb_epc->epc, func_no, epf_bar);
+	if (ret) {
+		dev_err(dev, "%s intf: peer SPAD BAR set failed\n",
+			pci_epc_interface_string(type));
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * epf_ntb_config_sspad_bar_clear() - Clears Config + Self scratchpad BAR
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+        +-----------------+
+ *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
+ *+-----------------+----+   +------------------+<-------+-----------------+
+ *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
+ *+-----------------+    +-->+------------------+<-------+-----------------+
+ *|       BAR2      |            Local Memory            |       BAR2      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR3      |                                    |       BAR3      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR4      |                                    |       BAR4      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR5      |                                    |       BAR5      |
+ *+-----------------+                                    +-----------------+
+ *  EP CONTROLLER 1                                        EP CONTROLLER 2
+ *
+ * It clears BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
+ * self scratchpad region (removes inbound ATU configuration). While BAR0 is
+ * the default self scratchpad BAR, an NTB could have other BARs for self
+ * scratchpad (because of reserved BARs). This function can get the exact BAR
+ * used for self scratchpad from epf_ntb_bar[BAR_CONFIG].
+ *
+ * Please note the self scratchpad region and config region is combined to
+ * a single region and mapped using the same BAR. Also note HOST2's peer
+ * scratchpad is HOST1's self scratchpad.
+ */
+static void epf_ntb_config_sspad_bar_clear(struct epf_ntb_epc *ntb_epc)
+{
+	struct pci_epf_bar *epf_bar;
+	enum pci_barno barno;
+	struct pci_epc *epc;
+	u8 func_no;
+
+	epc = ntb_epc->epc;
+	func_no = ntb_epc->func_no;
+	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
+	epf_bar = &ntb_epc->epf_bar[barno];
+	pci_epc_clear_bar(epc, func_no, epf_bar);
+}
+
+/**
+ * epf_ntb_config_sspad_bar_set() - Sets Config + Self scratchpad BAR
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+        +-----------------+
+ *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
+ *+-----------------+----+   +------------------+<-------+-----------------+
+ *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
+ *+-----------------+    +-->+------------------+<-------+-----------------+
+ *|       BAR2      |            Local Memory            |       BAR2      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR3      |                                    |       BAR3      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR4      |                                    |       BAR4      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR5      |                                    |       BAR5      |
+ *+-----------------+                                    +-----------------+
+ *  EP CONTROLLER 1                                        EP CONTROLLER 2
+ *
+ * It maps BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
+ * self scratchpad region. While BAR0 is the default self scratchpad BAR, an
+ * NTB could have other BARs for self scratchpad (because of reserved BARs).
+ * This function can get the exact BAR used for self scratchpad from
+ * epf_ntb_bar[BAR_CONFIG].
+ *
+ * Please note the self scratchpad region and config region is combined to
+ * a single region and mapped using the same BAR. Also note HOST2's peer
+ * scratchpad is HOST1's self scratchpad.
+ */
+static int epf_ntb_config_sspad_bar_set(struct epf_ntb_epc *ntb_epc)
+{
+	struct pci_epf_bar *epf_bar;
+	enum pci_barno barno;
+	struct epf_ntb *ntb;
+	struct pci_epc *epc;
+	struct device *dev;
+	u8 func_no;
+	int ret;
+
+	ntb = ntb_epc->epf_ntb;
+	dev = &ntb->epf->dev;
+
+	epc = ntb_epc->epc;
+	func_no = ntb_epc->func_no;
+	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
+	epf_bar = &ntb_epc->epf_bar[barno];
+
+	ret = pci_epc_set_bar(epc, func_no, epf_bar);
+	if (ret) {
+		dev_err(dev, "%s inft: Config/Status/SPAD BAR set failed\n",
+			pci_epc_interface_string(ntb_epc->type));
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * epf_ntb_config_spad_bar_free() - Free the physical memory associated with
+ *   config + scratchpad region
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ *+-----------------+------->+------------------+        +-----------------+
+ *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
+ *+-----------------+----+   +------------------+<-------+-----------------+
+ *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
+ *+-----------------+    +-->+------------------+<-------+-----------------+
+ *|       BAR2      |            Local Memory            |       BAR2      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR3      |                                    |       BAR3      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR4      |                                    |       BAR4      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR5      |                                    |       BAR5      |
+ *+-----------------+                                    +-----------------+
+ *  EP CONTROLLER 1                                        EP CONTROLLER 2
+ *
+ * This function frees the Local Memory mentioned in the above diagram. After
+ * invoking this function, any of config + self scrathpad region of HOST1 or
+ * peer scratchpad region of HOST2 should not be accessed.
+ */
+static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
+{
+	enum pci_epc_interface_type type;
+	struct epf_ntb_epc *ntb_epc;
+	enum pci_barno barno;
+	struct pci_epf *epf;
+
+	epf = ntb->epf;
+	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+		ntb_epc = ntb->epc[type];
+		barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
+		if (ntb_epc->reg)
+			pci_epf_free_space(epf, ntb_epc->reg, barno, type);
+	}
+}
+
+/**
+ * epf_ntb_config_spad_bar_alloc() - Allocate memory for config + scratchpad
+ *   region
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ *+-----------------+------->+------------------+        +-----------------+
+ *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
+ *+-----------------+----+   +------------------+<-------+-----------------+
+ *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
+ *+-----------------+    +-->+------------------+<-------+-----------------+
+ *|       BAR2      |            Local Memory            |       BAR2      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR3      |                                    |       BAR3      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR4      |                                    |       BAR4      |
+ *+-----------------+                                    +-----------------+
+ *|       BAR5      |                                    |       BAR5      |
+ *+-----------------+                                    +-----------------+
+ *  EP CONTROLLER 1                                        EP CONTROLLER 2
+ *
+ * This function allocates the Local Memory mentioned in the above diagram.
+ * The size of CONFIG REGION is sizeof(struct epf_ntb_ctrl) and size of
+ * SCRATCHPAD REGION is obtained from "spad-count" device tree property.
+ *
+ * The size of both config region and scratchpad region has to be aligned,
+ * since the scratchpad region will also be mapped as PEER SCRATCHPAD of
+ * other host using a separate BAR.
+ */
+static int
+epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb,
+			      enum pci_epc_interface_type type)
+{
+	const struct pci_epc_features *peer_epc_features, *epc_features;
+	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+	size_t msix_table_size, pba_size, align;
+	enum pci_barno peer_barno, barno;
+	struct epf_ntb_ctrl *ctrl;
+	struct device_node *node;
+	u32 spad_size, ctrl_size;
+	u64 size, peer_size;
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+	struct device *dev;
+	bool msix_capable;
+	u32 spad_count;
+	void *base;
+
+	epf = ntb->epf;
+	node = epf->node;
+	dev = &epf->dev;
+	ntb_epc = ntb->epc[type];
+	epc = ntb_epc->epc;
+
+	epc_features = ntb_epc->epc_features;
+	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
+	size = epc_features->bar_fixed_size[barno];
+	align = epc_features->align;
+
+	peer_ntb_epc = ntb->epc[!type];
+	peer_epc_features = peer_ntb_epc->epc_features;
+	peer_barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
+	peer_size = peer_epc_features->bar_fixed_size[barno];
+
+	/* Check if epc_features is populated incorrectly */
+	if ((!IS_ALIGNED(size, align)))
+		return -EINVAL;
+
+	spad_count = SPAD_COUNT;
+	of_property_read_u32(node, "spad-count", &spad_count);
+
+	ctrl_size = sizeof(struct epf_ntb_ctrl);
+	spad_size = spad_count * 4;
+
+	msix_capable = epc_features->msix_capable;
+	if (msix_capable) {
+		msix_table_size = PCI_MSIX_ENTRY_SIZE * ntb->db_count;
+		ctrl_size = ALIGN(ctrl_size, 8);
+		ntb_epc->msix_table_offset = ctrl_size;
+		ntb_epc->msix_bar = barno;
+		/* Align to QWORD or 8 Bytes */
+		pba_size = ALIGN(DIV_ROUND_UP(ntb->db_count, 8), 8);
+		ctrl_size = ctrl_size + msix_table_size + pba_size;
+	}
+
+	if (!align) {
+		ctrl_size = roundup_pow_of_two(ctrl_size);
+		spad_size = roundup_pow_of_two(spad_size);
+	} else {
+		ctrl_size = ALIGN(ctrl_size, align);
+		spad_size = ALIGN(spad_size, align);
+	}
+
+	if (peer_size) {
+		if (peer_size < spad_size)
+			spad_count = peer_size / 4;
+		spad_size = peer_size;
+	}
+
+	/*
+	 * In order to make sure SPAD offset is aligned to its size,
+	 * expand control region size to the size of SPAD if SPAD size
+	 * is greater than control region size.
+	 */
+	if (spad_size > ctrl_size)
+		ctrl_size = spad_size;
+
+	if (!size)
+		size = ctrl_size + spad_size;
+	else if (size < ctrl_size + spad_size)
+		return -EINVAL;
+
+	base = pci_epf_alloc_space(epf, size, barno, align, type);
+	if (!base) {
+		dev_err(dev, "%s intf: Config/Status/SPAD alloc region fail\n",
+			pci_epc_interface_string(type));
+		return -ENOMEM;
+	}
+
+	ntb_epc->reg = base;
+
+	ctrl = ntb_epc->reg;
+	ctrl->spad_offset = ctrl_size;
+	ctrl->spad_count = spad_count;
+	ctrl->num_mws = ntb->num_mws;
+	ctrl->db_entry_size = align ? align : 4;
+	ntb_epc->spad_size = spad_size;
+
+	return 0;
+}
+
+/**
+ * epf_ntb_config_spad_bar_alloc_interface() - Allocate memory for config +
+ *   scratchpad region for each of PRIMARY and SECONDARY interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Wrapper for epf_ntb_config_spad_bar_alloc() which allocates memory for
+ * config + scratchpad region for a specific interface
+ */
+static int epf_ntb_config_spad_bar_alloc_interface(struct epf_ntb *ntb)
+{
+	enum pci_epc_interface_type type;
+	struct device *dev;
+	int ret;
+
+	dev = &ntb->epf->dev;
+
+	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+		ret = epf_ntb_config_spad_bar_alloc(ntb, type);
+		if (ret) {
+			dev_err(dev, "%s intf: Config/SPAD BAR alloc failed\n",
+				pci_epc_interface_string(type));
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * epf_ntb_free_peer_mem() - Free's memory allocated in peers outbound address
+ *   space
+ * @ntb_epc: EPC associated with one of the HOST which holds peers outbound
+ *   address regions
+ *
+ *+-----------------+    +----->+----------------+-----------+-----------------+
+ *|       BAR0      |    |      |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
+ *+-----------------+    |      +----------------+           +-----------------+
+ *|       BAR1      |    |      |   Doorbell 2   +---------+ |                 |
+ *+-----------------+----+      +----------------+         | |                 |
+ *|       BAR2      |           |   Doorbell 3   +-------+ | +-----------------+
+ *+-----------------+----+      +----------------+       | +-> MSI|X ADDRESS 2 |
+ *|       BAR3      |    |      |   Doorbell 4   +-----+ |   +-----------------+
+ *+-----------------+    |      |----------------+     | |   |                 |
+ *|       BAR4      |    |      |                |     | |   +-----------------+
+ *+-----------------+    |      |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
+ *|       BAR5      |    |      |                |   | |     +-----------------+
+ *+-----------------+    +----->-----------------+   | |     |                 |
+ *  EP CONTROLLER 1             |                |   | |     +-----------------+
+ *                              |                |   | +---->+ MSI|X ADDRESS 4 |
+ *                              +----------------+   |       +-----------------+
+ *                     (A)       EP CONTROLLER 2     |       |                 |
+ *                                 (OB SPACE)        |       |                 |
+ *                                                   +------->      MW1        |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                   (B)     +-----------------+
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           +-----------------+
+ *                                                           PCI Address Space
+ *                                                           (Managed by HOST2)
+ *
+ * This function frees memory allocated in EP CONTROLLER 2 (OB SPACE) in the
+ * above diagram. It'll free Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4,
+ * MW1 (and MW2, MW3, MW4).
+ */
+static void epf_ntb_free_peer_mem(struct epf_ntb_epc *ntb_epc)
+{
+	struct pci_epf_bar *epf_bar;
+	void __iomem *mw_addr;
+	phys_addr_t phys_addr;
+	enum epf_ntb_bar bar;
+	enum pci_barno barno;
+	struct pci_epc *epc;
+	size_t size;
+
+	epc = ntb_epc->epc;
+
+	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
+		barno = ntb_epc->epf_ntb_bar[bar];
+		mw_addr = ntb_epc->mw_addr[barno];
+		epf_bar = &ntb_epc->epf_bar[barno];
+		phys_addr = epf_bar->phys_addr;
+		size = epf_bar->size;
+		if (mw_addr) {
+			pci_epc_mem_free_addr(epc, phys_addr, mw_addr, size);
+			ntb_epc->mw_addr[barno] = NULL;
+		}
+	}
+}
+
+/**
+ * epf_ntb_db_mw_bar_clear() - Clears doorbell and memory BAR
+ * @ntb_epc: EPC associated with one of the HOST which holds peers outbound
+ *   address
+ *
+ *+-----------------+    +----->+----------------+-----------+-----------------+
+ *|       BAR0      |    |      |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
+ *+-----------------+    |      +----------------+           +-----------------+
+ *|       BAR1      |    |      |   Doorbell 2   +---------+ |                 |
+ *+-----------------+----+      +----------------+         | |                 |
+ *|       BAR2      |           |   Doorbell 3   +-------+ | +-----------------+
+ *+-----------------+----+      +----------------+       | +-> MSI|X ADDRESS 2 |
+ *|       BAR3      |    |      |   Doorbell 4   +-----+ |   +-----------------+
+ *+-----------------+    |      |----------------+     | |   |                 |
+ *|       BAR4      |    |      |                |     | |   +-----------------+
+ *+-----------------+    |      |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
+ *|       BAR5      |    |      |                |   | |     +-----------------+
+ *+-----------------+    +----->-----------------+   | |     |                 |
+ *  EP CONTROLLER 1             |                |   | |     +-----------------+
+ *                              |                |   | +---->+ MSI|X ADDRESS 4 |
+ *                              +----------------+   |       +-----------------+
+ *                     (A)       EP CONTROLLER 2     |       |                 |
+ *                                 (OB SPACE)        |       |                 |
+ *                                                   +------->      MW1        |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                   (B)     +-----------------+
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           +-----------------+
+ *                                                           PCI Address Space
+ *                                                           (Managed by HOST2)
+ *
+ * This function clears doorbell and memory BARs (remove inbound ATU
+ * configuration). In the above diagram it clears BAR2 TO BAR5 of EP
+ * CONTROLLER 1 (Doorbell BAR, MW1 BAR, MW2 BAR, MW3 BAR and MW4 BAR).
+ */
+static void epf_ntb_db_mw_bar_clear(struct epf_ntb_epc *ntb_epc)
+{
+	struct pci_epf_bar *epf_bar;
+	enum epf_ntb_bar bar;
+	enum pci_barno barno;
+	struct pci_epc *epc;
+	u8 func_no;
+
+	epc = ntb_epc->epc;
+
+	func_no = ntb_epc->func_no;
+
+	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
+		barno = ntb_epc->epf_ntb_bar[bar];
+		epf_bar = &ntb_epc->epf_bar[barno];
+		pci_epc_clear_bar(epc, func_no, epf_bar);
+	}
+}
+
+/**
+ * epf_ntb_db_mw_bar_cleanup() - Clears doorbell/memory BAR and free memory
+ *   allocated in peers outbound address space
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * This function is a wrapper for epf_ntb_db_mw_bar_clear() which clears
+ * HOST1's BAR and epf_ntb_free_peer_mem() which frees up HOST2 outbound
+ * memory.
+ */
+static void epf_ntb_db_mw_bar_cleanup(struct epf_ntb *ntb,
+				      enum pci_epc_interface_type type)
+{
+	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+
+	ntb_epc = ntb->epc[type];
+	peer_ntb_epc = ntb->epc[!type];
+
+	epf_ntb_db_mw_bar_clear(ntb_epc);
+	epf_ntb_free_peer_mem(peer_ntb_epc);
+}
+
+/**
+ * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capaiblity
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Configures MSI/MSI-X capability for each interface with number of
+ * interrupts equal to "db-count" device tree parameter.
+ */
+static int epf_ntb_configure_interrupt(struct epf_ntb *ntb,
+				       enum pci_epc_interface_type type)
+{
+	const struct pci_epc_features *epc_features;
+	bool msix_capable, msi_capable;
+	struct epf_ntb_epc *ntb_epc;
+	struct device_node *node;
+	struct pci_epc *epc;
+	struct device *dev;
+	u32 db_count;
+	u8 func_no;
+	int ret;
+
+	ntb_epc = ntb->epc[type];
+	dev = &ntb->epf->dev;
+	node = ntb->epf->node;
+
+	epc_features = ntb_epc->epc_features;
+	msix_capable = epc_features->msix_capable;
+	msi_capable = epc_features->msi_capable;
+
+	if (!(msix_capable || msi_capable)) {
+		dev_err(dev, "MSI or MSI-X is required for doorbell\n");
+		return -EINVAL;
+	}
+
+	func_no = ntb_epc->func_no;
+
+	db_count = DB_COUNT;
+	of_property_read_u32(node, "db-count", &db_count);
+	if (db_count > MAX_DB_COUNT) {
+		dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT);
+		return -EINVAL;
+	}
+
+	ntb->db_count = db_count;
+	epc = ntb_epc->epc;
+
+	if (msi_capable) {
+		ret = pci_epc_set_msi(epc, func_no, db_count);
+		if (ret) {
+			dev_err(dev, "%s intf: MSI configuration failed\n",
+				pci_epc_interface_string(type));
+			return ret;
+		}
+	}
+
+	if (msix_capable) {
+		ret = pci_epc_set_msix(epc, func_no, db_count,
+				       ntb_epc->msix_bar,
+				       ntb_epc->msix_table_offset);
+		if (ret) {
+			dev_err(dev, "MSI configuration failed\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * epf_ntb_alloc_peer_mem() - Allocate memory in peers outbound address space
+ * @ntb_epc: EPC associated with one of the HOST whose BAR holds peers outbound
+ *   address
+ * @bar: BAR of @ntb_epc in for which memory has to be allocated (could be
+ *   BAR_DB_MW1, BAR_MW2, BAR_MW3, BAR_MW4)
+ * @peer_ntb_epc: EPC associated with HOST whose outbound address space is
+ *   used by @ntb_epc
+ * @size: Size of the address region that has to be allocated in peers OB SPACE
+ *
+ *
+ *+-----------------+    +----->+----------------+-----------+-----------------+
+ *|       BAR0      |    |      |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
+ *+-----------------+    |      +----------------+           +-----------------+
+ *|       BAR1      |    |      |   Doorbell 2   +---------+ |                 |
+ *+-----------------+----+      +----------------+         | |                 |
+ *|       BAR2      |           |   Doorbell 3   +-------+ | +-----------------+
+ *+-----------------+----+      +----------------+       | +-> MSI|X ADDRESS 2 |
+ *|       BAR3      |    |      |   Doorbell 4   +-----+ |   +-----------------+
+ *+-----------------+    |      |----------------+     | |   |                 |
+ *|       BAR4      |    |      |                |     | |   +-----------------+
+ *+-----------------+    |      |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
+ *|       BAR5      |    |      |                |   | |     +-----------------+
+ *+-----------------+    +----->-----------------+   | |     |                 |
+ *  EP CONTROLLER 1             |                |   | |     +-----------------+
+ *                              |                |   | +---->+ MSI|X ADDRESS 4 |
+ *                              +----------------+   |       +-----------------+
+ *                     (A)       EP CONTROLLER 2     |       |                 |
+ *                                 (OB SPACE)        |       |                 |
+ *                                                   +------->      MW1        |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                   (B)     +-----------------+
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           |                 |
+ *                                                           +-----------------+
+ *                                                           PCI Address Space
+ *                                                           (Managed by HOST2)
+ *
+ * This function allocates memory in OB space of EP CONTROLLER 2 in the
+ * above diagram. It'll allocate for Doorbell 1, Doorbell 2, Doorbell 3,
+ * Doorbell 4, MW1 (and MW2, MW3, MW4).
+ */
+static int
+epf_ntb_alloc_peer_mem(struct device *dev, struct epf_ntb_epc *ntb_epc,
+		       enum epf_ntb_bar bar, struct epf_ntb_epc *peer_ntb_epc,
+		       size_t size)
+{
+	const struct pci_epc_features *epc_features;
+	struct pci_epf_bar *epf_bar;
+	struct pci_epc *peer_epc;
+	phys_addr_t phys_addr;
+	void __iomem *mw_addr;
+	enum pci_barno barno;
+	size_t align;
+
+	epc_features = ntb_epc->epc_features;
+	align = epc_features->align;
+
+	if (size < 128)
+		size = 128;
+
+	if (align)
+		size = ALIGN(size, align);
+	else
+		size = roundup_pow_of_two(size);
+
+	peer_epc = peer_ntb_epc->epc;
+	mw_addr = pci_epc_mem_alloc_addr(peer_epc, &phys_addr, size);
+	if (!mw_addr) {
+		dev_err(dev, "%s intf: Failed to allocate OB address\n",
+			pci_epc_interface_string(peer_ntb_epc->type));
+		return -ENOMEM;
+	}
+
+	barno = ntb_epc->epf_ntb_bar[bar];
+	epf_bar = &ntb_epc->epf_bar[barno];
+	ntb_epc->mw_addr[barno] = mw_addr;
+
+	epf_bar->phys_addr = phys_addr;
+	epf_bar->size = size;
+	epf_bar->barno = barno;
+	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
+
+	return 0;
+}
+
+/**
+ * epf_ntb_db_mw_bar_init() - Configure Doorbell and Memory window BARs
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Wrapper for epf_ntb_alloc_peer_mem() and pci_epc_set_bar() that allocates
+ * memory in OB address space of HOST2 and configures BAR of HOST1
+ */
+static int epf_ntb_db_mw_bar_init(struct epf_ntb *ntb,
+				  enum pci_epc_interface_type type)
+{
+	const struct pci_epc_features *epc_features;
+	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
+	struct pci_epf_bar *epf_bar;
+	struct epf_ntb_ctrl *ctrl;
+	u32 num_mws, db_count;
+	enum epf_ntb_bar bar;
+	enum pci_barno barno;
+	struct pci_epc *epc;
+	struct device *dev;
+	size_t align;
+	int ret, i;
+	u8 func_no;
+	u64 size;
+
+	ntb_epc = ntb->epc[type];
+	peer_ntb_epc = ntb->epc[!type];
+
+	dev = &ntb->epf->dev;
+	epc_features = ntb_epc->epc_features;
+	align = epc_features->align;
+	func_no = ntb_epc->func_no;
+	epc = ntb_epc->epc;
+	num_mws = ntb->num_mws;
+	db_count = ntb->db_count;
+
+	for (bar = BAR_DB_MW1, i = 0; i < num_mws; bar++, i++) {
+		if (bar == BAR_DB_MW1) {
+			align = align ? align : 4;
+			size = db_count * align;
+			size = ALIGN(size, ntb->mws_size[i]);
+			ctrl = ntb_epc->reg;
+			ctrl->mw1_offset = size;
+			size += ntb->mws_size[i];
+		} else {
+			size = ntb->mws_size[i];
+		}
+
+		ret = epf_ntb_alloc_peer_mem(dev, ntb_epc, bar,
+					     peer_ntb_epc, size);
+		if (ret)
+			goto err_alloc_peer_mem;
+
+		barno = ntb_epc->epf_ntb_bar[bar];
+		epf_bar = &ntb_epc->epf_bar[barno];
+
+		ret = pci_epc_set_bar(epc, func_no, epf_bar);
+		if (ret) {
+			dev_err(dev, "%s intf: DoorBell BAR set failed\n",
+				pci_epc_interface_string(type));
+			goto err_alloc_peer_mem;
+		}
+	}
+
+	return 0;
+
+err_alloc_peer_mem:
+	epf_ntb_db_mw_bar_cleanup(ntb, type);
+
+	return ret;
+}
+
+/**
+ * epf_ntb_epc_destroy_interface() - Cleanup NTB EPC interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Unbind NTB function device from EPC and Relinquish reference to pci_epc
+ * for each of the interface.
+ */
+static void epf_ntb_epc_destroy_interface(struct epf_ntb *ntb,
+					  enum pci_epc_interface_type type)
+{
+	struct epf_ntb_epc *ntb_epc;
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+
+	if (type < 0)
+		return;
+
+	epf = ntb->epf;
+	ntb_epc = ntb->epc[type];
+	if (!ntb_epc)
+		return;
+	epc = ntb_epc->epc;
+	pci_epc_remove_epf(epc, epf, type);
+	pci_epc_put(epc);
+}
+
+/**
+ * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
+ */
+static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
+{
+	enum pci_epc_interface_type type;
+
+	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
+		epf_ntb_epc_destroy_interface(ntb, type);
+}
+
+/**
+ * epf_ntb_epc_create_interface() - Create and initialize NTB EPC interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @epc: struct pci_epc to which a particular NTB interface should be associated
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Allocate memory for NTB EPC interface and initialize it.
+ */
+static int
+epf_ntb_epc_create_interface(struct epf_ntb *ntb, struct pci_epc *epc,
+			     enum pci_epc_interface_type type)
+{
+	const struct pci_epc_features *epc_features;
+	struct pci_epf_bar *epf_bar;
+	struct epf_ntb_epc *ntb_epc;
+	struct pci_epf *epf;
+	struct device *dev;
+	u8 func_no;
+
+	dev = &ntb->epf->dev;
+
+	ntb_epc = devm_kzalloc(dev, sizeof(*ntb_epc), GFP_KERNEL);
+	if (!ntb_epc)
+		return -ENOMEM;
+
+	epf = ntb->epf;
+	if (type == PRIMARY_INTERFACE) {
+		func_no = epf->func_no;
+		epf_bar = epf->bar;
+	} else {
+		func_no = epf->sec_epc_func_no;
+		epf_bar = epf->sec_epc_bar;
+	}
+
+	ntb_epc->linkup = false;
+	ntb_epc->epc = epc;
+	ntb_epc->func_no = func_no;
+	ntb_epc->type = type;
+	ntb_epc->epf_bar = epf_bar;
+	ntb_epc->epf_ntb = ntb;
+
+	epc_features = pci_epc_get_features(epc, func_no);
+	if (!epc_features)
+		return -EINVAL;
+	ntb_epc->epc_features = epc_features;
+
+	ntb->epc[type] = ntb_epc;
+
+	return 0;
+}
+
+/**
+ * epf_ntb_epc_create() - Create and initialize NTB EPC interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Get a reference to EPC device and bind NTB function device to that EPC
+ * for each of the interface. It is also a wrapper to
+ * epf_ntb_epc_create_interface() to allocate memory for NTB EPC interface
+ * and initialize it
+ */
+static int epf_ntb_epc_create(struct epf_ntb *ntb)
+{
+	enum pci_epc_interface_type type;
+	struct device_node *node;
+	const char *epc_name;
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+	struct device *dev;
+	int ret;
+
+	epf = ntb->epf;
+	node = epf->node;
+	dev = &epf->dev;
+
+	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+		epc_name = pci_epc_interface_string(type);
+
+		epc = of_pci_epc_get_by_name(node, epc_name);
+		if (IS_ERR(epc)) {
+			if (PTR_ERR(epc) != -EPROBE_DEFER)
+				dev_err(dev, "%s intf: Failed to get EPC\n",
+					epc_name);
+			ret = PTR_ERR(epc);
+			goto err_epc_get;
+		}
+
+		ret = pci_epc_add_epf(epc, epf, type);
+		if (ret) {
+			dev_err(dev, "%s intf: Fail to add EPF to EPC\n",
+				epc_name);
+			goto err_epc_add;
+		}
+
+		ret = epf_ntb_epc_create_interface(ntb, epc, type);
+		if (ret) {
+			dev_err(dev, "%s intf: Fail to create NTB EPC\n",
+				epc_name);
+			goto err_epc_create;
+		}
+	}
+
+	return 0;
+
+err_epc_create:
+	pci_epc_remove_epf(epc, epf, type);
+
+err_epc_add:
+	pci_epc_put(epc);
+
+err_epc_get:
+	epf_ntb_epc_destroy_interface(ntb, type - 1);
+
+	return ret;
+}
+
+/**
+ * epf_ntb_init_epc_bar_interface() - Identify BARs to be used for each of
+ *   the NTB constructs (scratchpad region, doorbell, memorywindow)
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Identify the free BAR's to be used for each of BAR_CONFIG, BAR_PEER_SPAD,
+ * BAR_DB_MW1, BAR_MW2, BAR_MW3 and BAR_MW4.
+ */
+static int epf_ntb_init_epc_bar_interface(struct epf_ntb *ntb,
+					  enum pci_epc_interface_type type)
+{
+	const struct pci_epc_features *epc_features;
+	struct epf_ntb_epc *ntb_epc;
+	enum pci_barno barno;
+	enum epf_ntb_bar bar;
+	struct device *dev;
+	u32 num_mws;
+	int i;
+
+	barno = BAR_0;
+	ntb_epc = ntb->epc[type];
+	num_mws = ntb->num_mws;
+	dev = &ntb->epf->dev;
+	epc_features = ntb_epc->epc_features;
+
+	/* These are required BARs which are mandatory for NTB functionality */
+	for (bar = BAR_CONFIG; bar <= BAR_DB_MW1; bar++, barno++) {
+		barno = pci_epc_get_next_free_bar(epc_features, barno);
+		if (barno < 0) {
+			dev_err(dev, "%s intf: Fail to get NTB function BAR\n",
+				pci_epc_interface_string(type));
+			return barno;
+		}
+		ntb_epc->epf_ntb_bar[bar] = barno;
+	}
+
+	/* These are optional BARs which doesn't impact NTB functionality */
+	for (bar = BAR_MW2, i = 1; i < num_mws; bar++, barno++, i++) {
+		barno = pci_epc_get_next_free_bar(epc_features, barno);
+		if (barno < 0) {
+			ntb->num_mws = i;
+			dev_dbg(dev, "BAR not available for > MW%d\n", i + 1);
+		}
+		ntb_epc->epf_ntb_bar[bar] = barno;
+	}
+
+	return 0;
+}
+
+/**
+ * epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
+ * constructs (scratchpad region, doorbell, memorywindow)
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Wrapper to epf_ntb_init_epc_bar_interface() to identify the free BAR's
+ * to be used for each of BAR_CONFIG, BAR_PEER_SPAD, BAR_DB_MW1, BAR_MW2,
+ * BAR_MW3 and BAR_MW4 for all the interfaces.
+ */
+static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
+{
+	enum pci_epc_interface_type type;
+	struct device *dev;
+	int ret;
+
+	dev = &ntb->epf->dev;
+	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+		ret = epf_ntb_init_epc_bar_interface(ntb, type);
+		if (ret) {
+			dev_err(dev, "Fail to init EPC bar for %s interface\n",
+				pci_epc_interface_string(type));
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * epf_ntb_epc_init_interface() - Initialize NTB interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Wrapper to initialize a particular EPC interface and start the workqueue
+ * to check for commands from host. This function will write to the
+ * EP controller HW for configuring it.
+ */
+static int epf_ntb_epc_init_interface(struct epf_ntb *ntb,
+				      enum pci_epc_interface_type type)
+{
+	struct epf_ntb_epc *ntb_epc;
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+	struct device *dev;
+	u8 func_no;
+	int ret;
+
+	ntb_epc = ntb->epc[type];
+	epf = ntb->epf;
+	dev = &epf->dev;
+	epc = ntb_epc->epc;
+	func_no = ntb_epc->func_no;
+
+	ret = epf_ntb_config_sspad_bar_set(ntb->epc[type]);
+	if (ret) {
+		dev_err(dev, "%s intf: Config/self SPAD BAR init failed\n",
+			pci_epc_interface_string(type));
+		return ret;
+	}
+
+	ret = epf_ntb_peer_spad_bar_set(ntb, type);
+	if (ret) {
+		dev_err(dev, "%s intf: Peer SPAD BAR init failed\n",
+			pci_epc_interface_string(type));
+		goto err_peer_spad_bar_init;
+	}
+
+	ret = epf_ntb_configure_interrupt(ntb, type);
+	if (ret) {
+		dev_err(dev, "%s intf: Interrupt configuration failed\n",
+			pci_epc_interface_string(type));
+		goto err_peer_spad_bar_init;
+	}
+
+	ret = epf_ntb_db_mw_bar_init(ntb, type);
+	if (ret) {
+		dev_err(dev, "%s intf: DB/MW BAR init failed\n",
+			pci_epc_interface_string(type));
+		goto err_db_mw_bar_init;
+	}
+
+	ret = pci_epc_write_header(epc, func_no, epf->header);
+	if (ret) {
+		dev_err(dev, "%s intf: Configuration header write failed\n",
+			pci_epc_interface_string(type));
+		goto err_write_header;
+	}
+
+	INIT_DELAYED_WORK(&ntb->epc[type]->cmd_handler, epf_ntb_cmd_handler);
+	queue_work(kpcintb_workqueue, &ntb->epc[type]->cmd_handler.work);
+
+	return 0;
+
+err_write_header:
+	epf_ntb_db_mw_bar_cleanup(ntb, type);
+
+err_db_mw_bar_init:
+	epf_ntb_peer_spad_bar_clear(ntb->epc[type]);
+
+err_peer_spad_bar_init:
+	epf_ntb_config_sspad_bar_clear(ntb->epc[type]);
+
+	return ret;
+}
+
+/**
+ * epf_ntb_epc_cleanup_interface() - Cleanup NTB interface
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @type: PRIMARY interface or SECONDARY interface
+ *
+ * Wrapper to cleanup a particular NTB interface.
+ */
+static void epf_ntb_epc_cleanup_interface(struct epf_ntb *ntb,
+					  enum pci_epc_interface_type type)
+{
+	struct epf_ntb_epc *ntb_epc;
+
+	if (type < 0)
+		return;
+
+	ntb_epc = ntb->epc[type];
+	cancel_delayed_work(&ntb_epc->cmd_handler);
+	epf_ntb_db_mw_bar_cleanup(ntb, type);
+	epf_ntb_peer_spad_bar_clear(ntb_epc);
+	epf_ntb_config_sspad_bar_clear(ntb_epc);
+}
+
+/**
+ * epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Wrapper to cleanup all NTB interfaces.
+ */
+static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
+{
+	enum pci_epc_interface_type type;
+
+	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
+		epf_ntb_epc_cleanup_interface(ntb, type);
+}
+
+/**
+ * epf_ntb_epc_init() - Initialize all NTB interfaces
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Wrapper to initialize all NTB interface and start the workqueue
+ * to check for commands from host.
+ */
+static int epf_ntb_epc_init(struct epf_ntb *ntb)
+{
+	enum pci_epc_interface_type type;
+	struct device *dev;
+	int ret;
+
+	dev = &ntb->epf->dev;
+
+	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
+		ret = epf_ntb_epc_init_interface(ntb, type);
+		if (ret) {
+			dev_err(dev, "%s intf: Failed to initialize\n",
+				pci_epc_interface_string(type));
+			goto err_init_type;
+		}
+	}
+
+	return 0;
+
+err_init_type:
+	epf_ntb_epc_cleanup_interface(ntb, type - 1);
+
+	return ret;
+}
+
+/**
+ * epf_ntb_of_parse_mw() - Parse NTB device tree for Memory Window configuration
+ *   parameters
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @node: Device tree node of the NTB function
+ *
+ * Parse NTB device tree to get NTB Memory Window configuration parameters such
+ * as the number of memory window and the size of each memory window.
+ */
+static int epf_ntb_of_parse_mw(struct epf_ntb *ntb, struct device_node *node)
+{
+	struct device *dev;
+	u64 *mws_size;
+	u32 num_mws;
+	int ret;
+
+	dev = &ntb->epf->dev;
+	ret = of_property_read_u32(node, "num-mws", &num_mws);
+	if (ret) {
+		dev_err(dev, "Failed to get num-mws dt property\n");
+		return ret;
+	}
+
+	if (num_mws > MAX_MW) {
+		dev_err(dev, "Cannot support more than 4 memory window\n");
+		return ret;
+	}
+
+	mws_size = devm_kcalloc(dev, num_mws, sizeof(*mws_size), GFP_KERNEL);
+	if (!mws_size)
+		return -ENOMEM;
+
+	ret = of_property_read_u64_array(node, "mws-size", mws_size, num_mws);
+	if (ret) {
+		dev_err(dev, "Failed to get mws-size dt property\n");
+		return ret;
+	}
+
+	ntb->num_mws = num_mws;
+	ntb->mws_size = mws_size;
+
+	return 0;
+}
+
+/**
+ * epf_ntb_of_parse_mw() - Parse NTB device tree for configuration space header
+ *  and Memory Window configuration parameters
+ * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ *
+ * Parse NTB device tree to get endpoint configuration space headers like
+ * device-id, vendor-id etc., and Memory Window configuration parameters such
+ * as the number of memory window and the size of each memory window.
+ */
+static int epf_ntb_of_parse(struct epf_ntb *ntb)
+{
+	struct device_node *node;
+	struct pci_epf *epf;
+	struct device *dev;
+	int ret;
+
+	epf = ntb->epf;
+	node = epf->node;
+	dev = &epf->dev;
+
+	epf->header = &epf_ntb_header;
+	pci_epc_of_parse_header(node, epf->header);
+
+	ret = epf_ntb_of_parse_mw(ntb, node);
+	if (ret) {
+		dev_err(dev, "Invalid memory window configuration in DT\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * epf_ntb_probe() - Probe NTB function driver
+ * @epf: NTB endpoint function device
+ *
+ * Probe NTB function driver when endpoint function bus detects a NTB
+ * endpoint function. This allocates memory for epf_ntb and initializes
+ * both the endpoint controllers associated with NTB function device.
+ */
+static int epf_ntb_probe(struct pci_epf *epf)
+{
+	struct epf_ntb *ntb;
+	struct device *dev;
+	int ret;
+
+	dev = &epf->dev;
+
+	ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
+	if (!ntb)
+		return -ENOMEM;
+
+	ntb->epf = epf;
+
+	ret = epf_ntb_of_parse(ntb);
+	if (ret) {
+		dev_err(dev, "Failed to parse NTB DT node\n");
+		return ret;
+	}
+
+	ret = epf_ntb_epc_create(ntb);
+	if (ret) {
+		dev_err(dev, "Failed to create NTB EPC\n");
+		return ret;
+	}
+
+	ret = epf_ntb_init_epc_bar(ntb);
+	if (ret) {
+		dev_err(dev, "Failed to create NTB EPC\n");
+		goto err_bar_init;
+	}
+
+	ret = epf_ntb_config_spad_bar_alloc_interface(ntb);
+	if (ret) {
+		dev_err(dev, "Failed to allocate BAR memory\n");
+		goto err_bar_alloc;
+	}
+
+	ret = epf_ntb_epc_init(ntb);
+	if (ret) {
+		dev_err(dev, "Failed to initialize EPC\n");
+		goto err_bar_alloc;
+	}
+
+	epf_set_drvdata(epf, ntb);
+
+	return 0;
+
+err_bar_alloc:
+	epf_ntb_config_spad_bar_free(ntb);
+
+err_bar_init:
+	epf_ntb_epc_destroy(ntb);
+
+	return ret;
+}
+
+/**
+ * epf_ntb_remove() - Cleanup the initialization from epf_ntb_probe()
+ * @epf: NTB endpoint function device
+ *
+ * Cleanup the initialization from epf_ntb_probe()
+ */
+static int epf_ntb_remove(struct pci_epf *epf)
+{
+	struct epf_ntb *ntb = epf_get_drvdata(epf);
+
+	epf_ntb_epc_cleanup(ntb);
+	epf_ntb_config_spad_bar_free(ntb);
+	epf_ntb_epc_destroy(ntb);
+
+	return 0;
+}
+
+static const struct pci_epf_device_id epf_ntb_ids[] = {
+	{
+		.name = "pci-epf-ntb",
+	},
+	{},
+};
+
+static struct pci_epf_driver epf_ntb_driver = {
+	.driver.name	= "pci_epf_ntb",
+	.probe		= epf_ntb_probe,
+	.remove		= epf_ntb_remove,
+	.id_table	= epf_ntb_ids,
+	.owner		= THIS_MODULE,
+};
+
+static int __init epf_ntb_init(void)
+{
+	int ret;
+
+	kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
+					    WQ_HIGHPRI, 0);
+	ret = pci_epf_register_driver(&epf_ntb_driver);
+	if (ret) {
+		pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+module_init(epf_ntb_init);
+
+static void __exit epf_ntb_exit(void)
+{
+	pci_epf_unregister_driver(&epf_ntb_driver);
+}
+module_exit(epf_ntb_exit);
+
+MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 16/19] PCI: Add TI J721E device to pci ids
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (14 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 15/19] PCI: endpoint: Add EP function driver to provide NTB functionality Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 17/19] NTB: Add support for EPF PCI-Express Non-Transparent Bridge Kishon Vijay Abraham I
                   ` (3 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add TI J721E device to the pci id database. Since this device has
a configurable PCIe endpoint, it could be used with different
drivers.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/misc/pci_endpoint_test.c | 1 -
 include/linux/pci_ids.h          | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
index a70b17e5dd9a..a322e60fcec4 100644
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -68,7 +68,6 @@
 #define PCI_ENDPOINT_TEST_FLAGS			0x2c
 #define FLAG_USE_DMA				BIT(0)
 
-#define PCI_DEVICE_ID_TI_J721E			0xb00d
 #define PCI_DEVICE_ID_TI_AM654			0xb00c
 
 #define is_am654_pci_dev(pdev)		\
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 1dfc4e1dcb94..1707e67cd088 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -879,6 +879,7 @@
 #define PCI_DEVICE_ID_TI_X620		0xac8d
 #define PCI_DEVICE_ID_TI_X420		0xac8e
 #define PCI_DEVICE_ID_TI_XX20_FM	0xac8f
+#define PCI_DEVICE_ID_TI_J721E		0xb00d
 #define PCI_DEVICE_ID_TI_DRA74x		0xb500
 #define PCI_DEVICE_ID_TI_DRA72x		0xb501
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 17/19] NTB: Add support for EPF PCI-Express Non-Transparent Bridge
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (15 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 16/19] PCI: Add TI J721E device to pci ids Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 18/19] NTB: tool: Enable the NTB/PCIe link on the local or remote side of bridge Kishon Vijay Abraham I
                   ` (2 subsequent siblings)
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Add support for EPF PCI-Express Non-Transparent Bridge (NTB) device.
This driver is platform independent and could be used by any platform
which have multiple PCIe endpoint instances configured using the
pci-epf-ntb driver. The driver connnects to the standard NTB sub-system
interface. The EPF NTB device has configurable number of memory windows
(Max 4), configurable number of doorbell (Max 32), and configurable
number of scratch-pad registers.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/ntb/hw/Kconfig          |   1 +
 drivers/ntb/hw/Makefile         |   1 +
 drivers/ntb/hw/epf/Kconfig      |   5 +
 drivers/ntb/hw/epf/Makefile     |   1 +
 drivers/ntb/hw/epf/ntb_hw_epf.c | 752 ++++++++++++++++++++++++++++++++
 5 files changed, 760 insertions(+)
 create mode 100644 drivers/ntb/hw/epf/Kconfig
 create mode 100644 drivers/ntb/hw/epf/Makefile
 create mode 100644 drivers/ntb/hw/epf/ntb_hw_epf.c

diff --git a/drivers/ntb/hw/Kconfig b/drivers/ntb/hw/Kconfig
index e77c587060ff..c325be526b80 100644
--- a/drivers/ntb/hw/Kconfig
+++ b/drivers/ntb/hw/Kconfig
@@ -2,4 +2,5 @@
 source "drivers/ntb/hw/amd/Kconfig"
 source "drivers/ntb/hw/idt/Kconfig"
 source "drivers/ntb/hw/intel/Kconfig"
+source "drivers/ntb/hw/epf/Kconfig"
 source "drivers/ntb/hw/mscc/Kconfig"
diff --git a/drivers/ntb/hw/Makefile b/drivers/ntb/hw/Makefile
index 4714d6238845..223ca592b5f9 100644
--- a/drivers/ntb/hw/Makefile
+++ b/drivers/ntb/hw/Makefile
@@ -2,4 +2,5 @@
 obj-$(CONFIG_NTB_AMD)	+= amd/
 obj-$(CONFIG_NTB_IDT)	+= idt/
 obj-$(CONFIG_NTB_INTEL)	+= intel/
+obj-$(CONFIG_NTB_EPF)	+= epf/
 obj-$(CONFIG_NTB_SWITCHTEC) += mscc/
diff --git a/drivers/ntb/hw/epf/Kconfig b/drivers/ntb/hw/epf/Kconfig
new file mode 100644
index 000000000000..314485574bf8
--- /dev/null
+++ b/drivers/ntb/hw/epf/Kconfig
@@ -0,0 +1,5 @@
+config NTB_EPF
+	tristate "Generic EPF Non-Transparent Bridge support"
+	help
+	  This driver supports EPF NTB on configurable endpoint.
+	  If unsure, say N.
diff --git a/drivers/ntb/hw/epf/Makefile b/drivers/ntb/hw/epf/Makefile
new file mode 100644
index 000000000000..2f560a422bc6
--- /dev/null
+++ b/drivers/ntb/hw/epf/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_NTB_EPF) += ntb_hw_epf.o
diff --git a/drivers/ntb/hw/epf/ntb_hw_epf.c b/drivers/ntb/hw/epf/ntb_hw_epf.c
new file mode 100644
index 000000000000..d3ed1190bcfe
--- /dev/null
+++ b/drivers/ntb/hw/epf/ntb_hw_epf.c
@@ -0,0 +1,752 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Host side endpoint driver to implement Non-Transparent Bridge functionality
+ *
+ * Copyright (C) 2020 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/ntb.h>
+
+#define NTB_EPF_COMMAND		0x0
+#define CMD_CONFIGURE_DOORBELL	1
+#define CMD_TEARDOWN_DOORBELL	2
+#define CMD_CONFIGURE_MW	3
+#define CMD_TEARDOWN_MW		4
+#define CMD_LINK_UP		5
+#define CMD_LINK_DOWN		6
+
+#define NTB_EPF_ARGUMENT	0x4
+#define MSIX_ENABLE		BIT(16)
+
+#define NTB_EPF_CMD_STATUS	0x8
+#define COMMAND_STATUS_OK	1
+#define COMMAND_STATUS_ERROR	2
+
+#define NTB_EPF_LINK_STATUS	0x0A
+#define LINK_STATUS_UP		BIT(0)
+
+#define NTB_EPF_TOPOLOGY	0x0C
+#define NTB_EPF_LOWER_ADDR	0x10
+#define NTB_EPF_UPPER_ADDR	0x14
+#define NTB_EPF_LOWER_SIZE	0x18
+#define NTB_EPF_UPPER_SIZE	0x1C
+#define NTB_EPF_MW_COUNT	0x20
+#define NTB_EPF_MW1_OFFSET	0x24
+#define NTB_EPF_SPAD_OFFSET	0x28
+#define NTB_EPF_SPAD_COUNT	0x2C
+#define NTB_EPF_DB_ENTRY_SIZE	0x30
+#define NTB_EPF_DB_DATA(n)	(0x34 + (n) * 4)
+
+#define NTB_EPF_MIN_DB_COUNT	3
+#define NTB_EPF_MAX_DB_COUNT	31
+#define NTB_EPF_MW_OFFSET	2
+
+#define NTB_EPF_COMMAND_TIMEOUT	1000 /* 1 Sec */
+
+enum pci_barno {
+	BAR_0,
+	BAR_1,
+	BAR_2,
+	BAR_3,
+	BAR_4,
+	BAR_5,
+};
+
+struct ntb_epf_dev {
+	struct ntb_dev ntb;
+	struct device *dev;
+	/* Mutex to protect providing commands to NTB EPF */
+	struct mutex cmd_lock;
+
+	enum pci_barno ctrl_reg_bar;
+	enum pci_barno peer_spad_reg_bar;
+	enum pci_barno db_reg_bar;
+
+	unsigned int mw_count;
+	unsigned int spad_count;
+	unsigned int db_count;
+
+	void __iomem *ctrl_reg;
+	void __iomem *db_reg;
+	void __iomem *peer_spad_reg;
+
+	unsigned int self_spad;
+	unsigned int peer_spad;
+
+	int db_val;
+	u64 db_valid_mask;
+};
+
+#define ntb_ndev(__ntb) container_of(__ntb, struct ntb_epf_dev, ntb)
+
+struct ntb_epf_data {
+	/* BAR that contains both control region and self spad region */
+	enum pci_barno ctrl_reg_bar;
+	/* BAR that contains peer spad region */
+	enum pci_barno peer_spad_reg_bar;
+	/* BAR that contains Doorbell region and Memory window '1' */
+	enum pci_barno db_reg_bar;
+};
+
+static int ntb_epf_send_command(struct ntb_epf_dev *ndev, u32 command,
+				u32 argument)
+{
+	ktime_t timeout;
+	bool timedout;
+	int ret = 0;
+	u32 status;
+
+	mutex_lock(&ndev->cmd_lock);
+	writel(argument, ndev->ctrl_reg + NTB_EPF_ARGUMENT);
+	writel(command, ndev->ctrl_reg + NTB_EPF_COMMAND);
+
+	timeout = ktime_add_ms(ktime_get(), NTB_EPF_COMMAND_TIMEOUT);
+	while (1) {
+		timedout = ktime_after(ktime_get(), timeout);
+		status = readw(ndev->ctrl_reg + NTB_EPF_CMD_STATUS);
+
+		if (status == COMMAND_STATUS_ERROR) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (status == COMMAND_STATUS_OK)
+			break;
+
+		if (WARN_ON(timedout)) {
+			ret = -ETIMEDOUT;
+			break;
+		}
+
+		usleep_range(5, 10);
+	}
+
+	writew(0, ndev->ctrl_reg + NTB_EPF_CMD_STATUS);
+	mutex_unlock(&ndev->cmd_lock);
+
+	return ret;
+}
+
+static int ntb_epf_mw_to_bar(struct ntb_epf_dev *ndev, int idx)
+{
+	struct device *dev = ndev->dev;
+
+	if (idx < 0 || idx > ndev->mw_count) {
+		dev_err(dev, "Unsupported Memory Window index %d\n", idx);
+		return -EINVAL;
+	}
+
+	return idx + 2;
+}
+
+static int ntb_epf_mw_count(struct ntb_dev *ntb, int pidx)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	return ndev->mw_count;
+}
+
+static int ntb_epf_mw_get_align(struct ntb_dev *ntb, int pidx, int idx,
+				resource_size_t *addr_align,
+				resource_size_t *size_align,
+				resource_size_t *size_max)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	bar = ntb_epf_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	if (addr_align)
+		*addr_align = SZ_4K;
+
+	if (size_align)
+		*size_align = 1;
+
+	if (size_max)
+		*size_max = pci_resource_len(ndev->ntb.pdev, bar);
+
+	return 0;
+}
+
+static u64 ntb_epf_link_is_up(struct ntb_dev *ntb,
+			      enum ntb_speed *speed,
+			      enum ntb_width *width)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	u32 status;
+
+	status = readw(ndev->ctrl_reg + NTB_EPF_LINK_STATUS);
+
+	return status & LINK_STATUS_UP;
+}
+
+static u32 ntb_epf_spad_read(struct ntb_dev *ntb, int idx)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count) {
+		dev_err(dev, "READ: Invalid ScratchPad Index %d\n", idx);
+		return 0;
+	}
+
+	offset = readl(ndev->ctrl_reg + NTB_EPF_SPAD_OFFSET);
+	offset += (idx << 2);
+
+	return readl(ndev->ctrl_reg + offset);
+}
+
+static int ntb_epf_spad_write(struct ntb_dev *ntb,
+			      int idx, u32 val)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count) {
+		dev_err(dev, "WRITE: Invalid ScratchPad Index %d\n", idx);
+		return -EINVAL;
+	}
+
+	offset = readl(ndev->ctrl_reg + NTB_EPF_SPAD_OFFSET);
+	offset += (idx << 2);
+	writel(val, ndev->ctrl_reg);
+
+	return 0;
+}
+
+static u32 ntb_epf_peer_spad_read(struct ntb_dev *ntb, int pidx, int idx)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	u32 offset;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	if (idx < 0 || idx >= ndev->spad_count) {
+		dev_err(dev, "WRITE: Invalid Peer ScratchPad Index %d\n", idx);
+		return -EINVAL;
+	}
+
+	offset = (idx << 2);
+	return readl(ndev->peer_spad_reg + offset);
+}
+
+static int ntb_epf_peer_spad_write(struct ntb_dev *ntb, int pidx,
+				   int idx, u32 val)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	u32 offset;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	if (idx < 0 || idx >= ndev->spad_count) {
+		dev_err(dev, "WRITE: Invalid Peer ScratchPad Index %d\n", idx);
+		return -EINVAL;
+	}
+
+	offset = (idx << 2);
+	writel(val, ndev->peer_spad_reg + offset);
+
+	return 0;
+}
+
+static int ntb_epf_link_enable(struct ntb_dev *ntb,
+			       enum ntb_speed max_speed,
+			       enum ntb_width max_width)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	int ret;
+
+	ret = ntb_epf_send_command(ndev, CMD_LINK_UP, 0);
+	if (ret) {
+		dev_err(dev, "Fail to enable link\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ntb_epf_link_disable(struct ntb_dev *ntb)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	int ret;
+
+	ret = ntb_epf_send_command(ndev, CMD_LINK_DOWN, 0);
+	if (ret) {
+		dev_err(dev, "Fail to disable link\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static irqreturn_t ndev_vec_isr(int irq, void *dev)
+{
+	struct ntb_epf_dev *ndev = dev;
+	int irq_no;
+
+	irq_no = irq - pci_irq_vector(ndev->ntb.pdev, 0);
+	ndev->db_val = irq_no + 1;
+
+	if (irq_no == 0)
+		ntb_link_event(&ndev->ntb);
+	else
+		ntb_db_event(&ndev->ntb, irq_no);
+
+	return IRQ_HANDLED;
+}
+
+static int ntb_epf_init_isr(struct ntb_epf_dev *ndev, int msi_min, int msi_max)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+	struct device *dev = ndev->dev;
+	u32 argument = MSIX_ENABLE;
+	int irq;
+	int ret;
+	int i;
+
+	irq = pci_alloc_irq_vectors(pdev, msi_min, msi_max, PCI_IRQ_MSIX);
+	if (irq < 0) {
+		dev_dbg(dev, "Failed to get MSIX interrupts\n");
+		irq = pci_alloc_irq_vectors(pdev, msi_min, msi_max,
+					    PCI_IRQ_MSI);
+		if (irq < 0) {
+			dev_err(dev, "Failed to get MSI interrupts\n");
+			return irq;
+		}
+		argument &= ~MSIX_ENABLE;
+	}
+
+	for (i = 0; i < irq; i++) {
+		ret = devm_request_irq(&pdev->dev, pci_irq_vector(pdev, i),
+				       ndev_vec_isr, IRQF_SHARED, "ntb_epf",
+				       ndev);
+		if (ret) {
+			dev_err(dev, "Failed to request irq\n");
+			goto err_request_irq;
+		}
+	}
+
+	ndev->db_count = irq - 1;
+
+	ret = ntb_epf_send_command(ndev, CMD_CONFIGURE_DOORBELL,
+				   argument | irq);
+	if (ret) {
+		dev_err(dev, "Failed to configure doorbell\n");
+		goto err_configure_db;
+	}
+
+	return 0;
+
+err_configure_db:
+	for (i = 0; i < ndev->db_count + 1; i++)
+		devm_free_irq(dev, pci_irq_vector(pdev, i), ndev);
+
+err_request_irq:
+	pci_free_irq_vectors(pdev);
+
+	return ret;
+}
+
+static int ntb_epf_peer_mw_count(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->mw_count;
+}
+
+static int ntb_epf_spad_count(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->spad_count;
+}
+
+static u64 ntb_epf_db_valid_mask(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->db_valid_mask;
+}
+
+static int ntb_epf_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	return 0;
+}
+
+static int ntb_epf_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
+				dma_addr_t addr, resource_size_t size)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	resource_size_t mw_size;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	bar = idx + NTB_EPF_MW_OFFSET;
+
+	mw_size = pci_resource_len(ntb->pdev, bar);
+
+	if (size > mw_size) {
+		dev_err(dev, "Size:%llx is greater than the MW size %llx\n",
+			size, mw_size);
+		return -EINVAL;
+	}
+
+	writel(lower_32_bits(addr), ndev->ctrl_reg + NTB_EPF_LOWER_ADDR);
+	writel(upper_32_bits(addr), ndev->ctrl_reg + NTB_EPF_UPPER_ADDR);
+	writel(lower_32_bits(size), ndev->ctrl_reg + NTB_EPF_LOWER_SIZE);
+	writel(upper_32_bits(size), ndev->ctrl_reg + NTB_EPF_UPPER_SIZE);
+	ntb_epf_send_command(ndev, CMD_CONFIGURE_MW, idx);
+
+	return 0;
+}
+
+static int ntb_epf_mw_clear_trans(struct ntb_dev *ntb, int pidx, int idx)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	int ret = 0;
+
+	ntb_epf_send_command(ndev, CMD_TEARDOWN_MW, idx);
+	if (ret)
+		dev_err(dev, "Failed to teardown memory window\n");
+
+	return ret;
+}
+
+static int ntb_epf_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
+				    phys_addr_t *base, resource_size_t *size)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	u32 offset = 0;
+	int bar;
+
+	if (idx == 0)
+		offset = readl(ndev->ctrl_reg + NTB_EPF_MW1_OFFSET);
+
+	bar = idx + NTB_EPF_MW_OFFSET;
+
+	if (base)
+		*base = pci_resource_start(ndev->ntb.pdev, bar) + offset;
+
+	if (size)
+		*size = pci_resource_len(ndev->ntb.pdev, bar) - offset;
+
+	return 0;
+}
+
+static int ntb_epf_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	u32 interrupt_num = ffs(db_bits) + 1;
+	struct device *dev = ndev->dev;
+	u32 db_entry_size;
+	u32 db_data;
+
+	if (interrupt_num > ndev->db_count) {
+		dev_err(dev, "DB interrupt %d greater than Max Supported %d\n",
+			interrupt_num, ndev->db_count);
+		return -EINVAL;
+	}
+
+	db_entry_size = readl(ndev->ctrl_reg + NTB_EPF_DB_ENTRY_SIZE);
+
+	db_data = readl(ndev->ctrl_reg + NTB_EPF_DB_DATA(interrupt_num));
+	writel(db_data, ndev->db_reg + (db_entry_size * interrupt_num));
+
+	return 0;
+}
+
+static u64 ntb_epf_db_read(struct ntb_dev *ntb)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+
+	return ndev->db_val;
+}
+
+static int ntb_epf_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	return 0;
+}
+
+static int ntb_epf_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+
+	ndev->db_val = 0;
+
+	return 0;
+}
+
+static const struct ntb_dev_ops ntb_epf_ops = {
+	.mw_count		= ntb_epf_mw_count,
+	.spad_count		= ntb_epf_spad_count,
+	.peer_mw_count		= ntb_epf_peer_mw_count,
+	.db_valid_mask		= ntb_epf_db_valid_mask,
+	.db_set_mask		= ntb_epf_db_set_mask,
+	.mw_set_trans		= ntb_epf_mw_set_trans,
+	.mw_clear_trans		= ntb_epf_mw_clear_trans,
+	.peer_mw_get_addr	= ntb_epf_peer_mw_get_addr,
+	.link_enable		= ntb_epf_link_enable,
+	.spad_read		= ntb_epf_spad_read,
+	.spad_write		= ntb_epf_spad_write,
+	.peer_spad_read		= ntb_epf_peer_spad_read,
+	.peer_spad_write	= ntb_epf_peer_spad_write,
+	.peer_db_set		= ntb_epf_peer_db_set,
+	.db_read		= ntb_epf_db_read,
+	.mw_get_align		= ntb_epf_mw_get_align,
+	.link_is_up		= ntb_epf_link_is_up,
+	.db_clear_mask		= ntb_epf_db_clear_mask,
+	.db_clear		= ntb_epf_db_clear,
+	.link_disable		= ntb_epf_link_disable,
+};
+
+static inline void ntb_epf_init_struct(struct ntb_epf_dev *ndev,
+				       struct pci_dev *pdev)
+{
+	ndev->ntb.pdev = pdev;
+	ndev->ntb.topo = NTB_TOPO_NONE;
+	ndev->ntb.ops = &ntb_epf_ops;
+}
+
+static int ntb_epf_init_dev(struct ntb_epf_dev *ndev)
+{
+	struct device *dev = ndev->dev;
+	int ret;
+
+	/* One Link interrupt and rest doorbell interrupt */
+	ret = ntb_epf_init_isr(ndev, NTB_EPF_MIN_DB_COUNT + 1,
+			       NTB_EPF_MAX_DB_COUNT + 1);
+	if (ret) {
+		dev_err(dev, "Failed to init ISR\n");
+		return ret;
+	}
+
+	ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+	ndev->mw_count = readl(ndev->ctrl_reg + NTB_EPF_MW_COUNT);
+	ndev->spad_count = readl(ndev->ctrl_reg + NTB_EPF_SPAD_COUNT);
+
+	return 0;
+}
+
+static int ntb_epf_init_pci(struct ntb_epf_dev *ndev,
+			    struct pci_dev *pdev)
+{
+	struct device *dev = ndev->dev;
+	int ret;
+
+	pci_set_drvdata(pdev, ndev);
+
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		dev_err(dev, "Cannot enable PCI device\n");
+		goto err_pci_enable;
+	}
+
+	ret = pci_request_regions(pdev, "ntb");
+	if (ret) {
+		dev_err(dev, "Cannot obtain PCI resources\n");
+		goto err_pci_regions;
+	}
+
+	pci_set_master(pdev);
+
+	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+	if (ret) {
+		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+		if (ret) {
+			dev_err(dev, "Cannot set DMA mask\n");
+			goto err_dma_mask;
+		}
+		dev_warn(&pdev->dev, "Cannot DMA highmem\n");
+	}
+
+	ndev->ctrl_reg = pci_iomap(pdev, 0, 0);
+	if (!ndev->ctrl_reg) {
+		ret = -EIO;
+		goto err_dma_mask;
+	}
+
+	ndev->peer_spad_reg = pci_iomap(pdev, 1, 0);
+	if (!ndev->peer_spad_reg) {
+		ret = -EIO;
+		goto err_dma_mask;
+	}
+
+	ndev->db_reg = pci_iomap(pdev, 2, 0);
+	if (!ndev->db_reg) {
+		ret = -EIO;
+		goto err_dma_mask;
+	}
+
+	return 0;
+
+err_dma_mask:
+	pci_clear_master(pdev);
+
+err_pci_regions:
+	pci_disable_device(pdev);
+
+err_pci_enable:
+	pci_set_drvdata(pdev, NULL);
+
+	return ret;
+}
+
+static void ntb_epf_deinit_pci(struct ntb_epf_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+
+	pci_iounmap(pdev, ndev->ctrl_reg);
+	pci_iounmap(pdev, ndev->peer_spad_reg);
+	pci_iounmap(pdev, ndev->db_reg);
+
+	pci_clear_master(pdev);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	pci_set_drvdata(pdev, NULL);
+}
+
+static void ntb_epf_cleanup_isr(struct ntb_epf_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+	struct device *dev = &pdev->dev;
+	int i;
+
+	ntb_epf_send_command(ndev, CMD_TEARDOWN_DOORBELL, ndev->db_count + 1);
+
+	for (i = 0; i < ndev->db_count + 1; i++)
+		devm_free_irq(dev, pci_irq_vector(pdev, i), ndev);
+	pci_free_irq_vectors(pdev);
+}
+
+static int ntb_epf_pci_probe(struct pci_dev *pdev,
+			     const struct pci_device_id *id)
+{
+	enum pci_barno peer_spad_reg_bar = BAR_1;
+	enum pci_barno ctrl_reg_bar = BAR_0;
+	enum pci_barno db_reg_bar = BAR_2;
+	struct device *dev = &pdev->dev;
+	struct ntb_epf_data *data;
+	struct ntb_epf_dev *ndev;
+	int ret;
+
+	if (pci_is_bridge(pdev))
+		return -ENODEV;
+
+	ndev = devm_kzalloc(dev, sizeof(*ndev), GFP_KERNEL);
+	if (!ndev)
+		return -ENOMEM;
+
+	data = (struct ntb_epf_data *)id->driver_data;
+	if (data) {
+		if (data->peer_spad_reg_bar)
+			peer_spad_reg_bar = data->peer_spad_reg_bar;
+		if (data->ctrl_reg_bar)
+			ctrl_reg_bar = data->ctrl_reg_bar;
+		if (data->db_reg_bar)
+			db_reg_bar = data->db_reg_bar;
+	}
+
+	ndev->peer_spad_reg_bar = peer_spad_reg_bar;
+	ndev->ctrl_reg_bar = ctrl_reg_bar;
+	ndev->db_reg_bar = db_reg_bar;
+	ndev->dev = dev;
+
+	ntb_epf_init_struct(ndev, pdev);
+	mutex_init(&ndev->cmd_lock);
+
+	ret = ntb_epf_init_pci(ndev, pdev);
+	if (ret) {
+		dev_err(dev, "Failed to init PCI\n");
+		return ret;
+	}
+
+	ret = ntb_epf_init_dev(ndev);
+	if (ret) {
+		dev_err(dev, "Failed to init device\n");
+		goto err_init_dev;
+	}
+
+	ret = ntb_register_device(&ndev->ntb);
+	if (ret) {
+		dev_err(dev, "Failed to register NTB device\n");
+		goto err_register_dev;
+	}
+
+	return 0;
+
+err_register_dev:
+	ntb_epf_cleanup_isr(ndev);
+
+err_init_dev:
+	ntb_epf_deinit_pci(ndev);
+
+	return ret;
+}
+
+static void ntb_epf_pci_remove(struct pci_dev *pdev)
+{
+	struct ntb_epf_dev *ndev = pci_get_drvdata(pdev);
+
+	ntb_unregister_device(&ndev->ntb);
+	ntb_epf_cleanup_isr(ndev);
+	ntb_epf_deinit_pci(ndev);
+	kfree(ndev);
+}
+
+static const struct ntb_epf_data j721e_data = {
+	.ctrl_reg_bar = BAR_0,
+	.peer_spad_reg_bar = BAR_1,
+	.db_reg_bar = BAR_2,
+};
+
+static const struct pci_device_id ntb_epf_pci_tbl[] = {
+	{
+		PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_J721E),
+		.driver_data = (kernel_ulong_t)&j721e_data,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(pci, ntb_epf_pci_tbl);
+
+static struct pci_driver ntb_epf_pci_driver = {
+	.name		= KBUILD_MODNAME,
+	.id_table	= ntb_epf_pci_tbl,
+	.probe		= ntb_epf_pci_probe,
+	.remove		= ntb_epf_pci_remove,
+};
+module_pci_driver(ntb_epf_pci_driver);
+
+MODULE_DESCRIPTION("PCI ENDPOINT NTB HOST DRIVER");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 18/19] NTB: tool: Enable the NTB/PCIe link on the local or remote side of bridge
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (16 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 17/19] NTB: Add support for EPF PCI-Express Non-Transparent Bridge Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-14 14:59 ` [PATCH 19/19] NTB: ntb_perf/ntb_tool: Use PCI device for dma_alloc_coherent() Kishon Vijay Abraham I
  2020-05-22 16:11 ` [PATCH 00/19] Implement NTB Controller using multiple PCI EP Rob Herring
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

Invoke ntb_link_enable() to enable the NTB/PCIe link on the local
or remote side of the bridge.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/ntb/test/ntb_tool.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
index 69da758fe64c..4b4f9e2a2c43 100644
--- a/drivers/ntb/test/ntb_tool.c
+++ b/drivers/ntb/test/ntb_tool.c
@@ -1638,6 +1638,7 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
 
 	tool_setup_dbgfs(tc);
 
+	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
 	return 0;
 
 err_clear_mws:
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH 19/19] NTB: ntb_perf/ntb_tool: Use PCI device for dma_alloc_coherent()
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (17 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 18/19] NTB: tool: Enable the NTB/PCIe link on the local or remote side of bridge Kishon Vijay Abraham I
@ 2020-05-14 14:59 ` Kishon Vijay Abraham I
  2020-05-22 16:11 ` [PATCH 00/19] Implement NTB Controller using multiple PCI EP Rob Herring
  19 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-14 14:59 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb, Kishon Vijay Abraham I

NTB device is not a real device and the piece of hardware actually
doing the DMA is the PCI device itself. Fix ntb_perf.c and ntb_tool.c
to use PCI device for dma_alloc_coherent() instead of NTB device.
ntb_transport.c already uses PCI device for dma_alloc_coherent().

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/ntb/test/ntb_perf.c | 3 ++-
 drivers/ntb/test/ntb_tool.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
index 972f6d984f6d..7f830a3e5b14 100644
--- a/drivers/ntb/test/ntb_perf.c
+++ b/drivers/ntb/test/ntb_perf.c
@@ -566,6 +566,7 @@ static int perf_setup_inbuf(struct perf_peer *peer)
 {
 	resource_size_t xlat_align, size_align, size_max;
 	struct perf_ctx *perf = peer->perf;
+	struct pci_dev *pdev = perf->ntb->pdev;
 	int ret;
 
 	/* Get inbound MW parameters */
@@ -586,7 +587,7 @@ static int perf_setup_inbuf(struct perf_peer *peer)
 
 	perf_free_inbuf(peer);
 
-	peer->inbuf = dma_alloc_coherent(&perf->ntb->dev, peer->inbuf_size,
+	peer->inbuf = dma_alloc_coherent(&pdev->dev, peer->inbuf_size,
 					 &peer->inbuf_xlat, GFP_KERNEL);
 	if (!peer->inbuf) {
 		dev_err(&perf->ntb->dev, "Failed to alloc inbuf of %pa\n",
diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
index 4b4f9e2a2c43..5c9f034122b7 100644
--- a/drivers/ntb/test/ntb_tool.c
+++ b/drivers/ntb/test/ntb_tool.c
@@ -576,6 +576,7 @@ static int tool_setup_mw(struct tool_ctx *tc, int pidx, int widx,
 {
 	resource_size_t size, addr_align, size_align;
 	struct tool_mw *inmw = &tc->peers[pidx].inmws[widx];
+	struct pci_dev *pdev = tc->ntb->pdev;
 	char buf[TOOL_BUF_LEN];
 	int ret;
 
@@ -590,7 +591,7 @@ static int tool_setup_mw(struct tool_ctx *tc, int pidx, int widx,
 	inmw->size = min_t(resource_size_t, req_size, size);
 	inmw->size = round_up(inmw->size, addr_align);
 	inmw->size = round_up(inmw->size, size_align);
-	inmw->mm_base = dma_alloc_coherent(&tc->ntb->dev, inmw->size,
+	inmw->mm_base = dma_alloc_coherent(&pdev->dev, inmw->size,
 					   &inmw->dma_base, GFP_KERNEL);
 	if (!inmw->mm_base)
 		return -ENOMEM;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* Re: [PATCH 01/19] dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device
  2020-05-14 14:59 ` [PATCH 01/19] dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device Kishon Vijay Abraham I
@ 2020-05-15  2:38   ` Rob Herring
  2020-05-22  5:53   ` Kishon Vijay Abraham I
  1 sibling, 0 replies; 24+ messages in thread
From: Rob Herring @ 2020-05-15  2:38 UTC (permalink / raw)
  To: Kishon Vijay Abraham I
  Cc: linux-pci, devicetree, linux-ntb, Arnd Bergmann,
	Greg Kroah-Hartman, linux-doc, Rob Herring, Jonathan Corbet,
	linux-kernel, Bjorn Helgaas, Allen Hubbe, Tom Joseph, Dave Jiang,
	Jon Mason, Lorenzo Pieralisi

On Thu, 14 May 2020 20:29:09 +0530, Kishon Vijay Abraham I wrote:
> Add device tree schema for PCI endpoint function bus to which
> endpoint function devices should be attached. Then add device tree
> schema for PCI endpoint function device to include bindings thats
> generic to all endpoint functions. Finally add device tree schema
> for PCI endpoint NTB function device by including the generic
> device tree schema for PCIe endpoint function.
> 
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  .../bindings/pci/endpoint/pci-epf-bus.yaml    | 42 +++++++++++
>  .../bindings/pci/endpoint/pci-epf-device.yaml | 69 +++++++++++++++++++
>  .../bindings/pci/endpoint/pci-epf-ntb.yaml    | 68 ++++++++++++++++++
>  3 files changed, 179 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml
>  create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml
>  create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml
> 


My bot found errors running 'make dt_binding_check' on your patch:

Traceback (most recent call last):
  File "/usr/local/bin/dt-doc-validate", line 64, in <module>
    ret = check_doc(args.yamldt)
  File "/usr/local/bin/dt-doc-validate", line 25, in check_doc
    testtree = dtschema.load(filename, line_number=line_number, duplicate_keys=False)
  File "/usr/local/lib/python3.6/dist-packages/dtschema/lib.py", line 592, in load
    return yaml.load(f.read())
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/main.py", line 343, in load
    return constructor.get_single_data()
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 113, in get_single_data
    return self.construct_document(node)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 123, in construct_document
    for _dummy in generator:
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 723, in construct_yaml_map
    value = self.construct_mapping(node)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 440, in construct_mapping
    return BaseConstructor.construct_mapping(self, node, deep=deep)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 257, in construct_mapping
    if self.check_mapping_key(node, key_node, mapping, key, value):
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 295, in check_mapping_key
    raise DuplicateKeyError(*args)
ruamel.yaml.constructor.DuplicateKeyError: while constructing a mapping
  in "<unicode string>", line 5, column 1
found duplicate key "properties" with value "{}" (original value: "{}")
  in "<unicode string>", line 17, column 1

To suppress this check see:
    http://yaml.readthedocs.io/en/latest/api.html#duplicate-keys

Duplicate keys will become an error in future releases, and are errors
by default when using the new API.

Documentation/devicetree/bindings/Makefile:12: recipe for target 'Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.example.dts' failed
make[1]: *** [Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.example.dts] Error 1
make[1]: *** Waiting for unfinished jobs....
Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml: while constructing a mapping
  in "<unicode string>", line 5, column 1
found duplicate key "properties" with value "{}" (original value: "{}")
  in "<unicode string>", line 17, column 1

To suppress this check see:
    http://yaml.readthedocs.io/en/latest/api.html#duplicate-keys

Duplicate keys will become an error in future releases, and are errors
by default when using the new API.

Traceback (most recent call last):
  File "/usr/local/bin/dt-mk-schema", line 34, in <module>
    schemas = dtschema.process_schemas(args.schemas, core_schema=(not args.useronly))
  File "/usr/local/lib/python3.6/dist-packages/dtschema/lib.py", line 554, in process_schemas
    sch = process_schema(os.path.abspath(filename))
  File "/usr/local/lib/python3.6/dist-packages/dtschema/lib.py", line 507, in process_schema
    schema = load_schema(filename)
  File "/usr/local/lib/python3.6/dist-packages/dtschema/lib.py", line 123, in load_schema
    return do_load(os.path.join(schema_basedir, schema))
  File "/usr/local/lib/python3.6/dist-packages/dtschema/lib.py", line 108, in do_load
    return yaml.load(tmp)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/main.py", line 343, in load
    return constructor.get_single_data()
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 113, in get_single_data
    return self.construct_document(node)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 123, in construct_document
    for _dummy in generator:
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 723, in construct_yaml_map
    value = self.construct_mapping(node)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 440, in construct_mapping
    return BaseConstructor.construct_mapping(self, node, deep=deep)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 257, in construct_mapping
    if self.check_mapping_key(node, key_node, mapping, key, value):
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 295, in check_mapping_key
    raise DuplicateKeyError(*args)
ruamel.yaml.constructor.DuplicateKeyError: while constructing a mapping
  in "<unicode string>", line 5, column 1
found duplicate key "properties" with value "{}" (original value: "{}")
  in "<unicode string>", line 17, column 1

To suppress this check see:
    http://yaml.readthedocs.io/en/latest/api.html#duplicate-keys

Duplicate keys will become an error in future releases, and are errors
by default when using the new API.

Documentation/devicetree/bindings/Makefile:41: recipe for target 'Documentation/devicetree/bindings/processed-schema-examples.yaml' failed
make[1]: *** [Documentation/devicetree/bindings/processed-schema-examples.yaml] Error 123
make[1]: *** Deleting file 'Documentation/devicetree/bindings/processed-schema-examples.yaml'
Traceback (most recent call last):
  File "/usr/local/bin/dt-mk-schema", line 34, in <module>
    schemas = dtschema.process_schemas(args.schemas, core_schema=(not args.useronly))
  File "/usr/local/lib/python3.6/dist-packages/dtschema/lib.py", line 554, in process_schemas
    sch = process_schema(os.path.abspath(filename))
  File "/usr/local/lib/python3.6/dist-packages/dtschema/lib.py", line 507, in process_schema
    schema = load_schema(filename)
  File "/usr/local/lib/python3.6/dist-packages/dtschema/lib.py", line 123, in load_schema
    return do_load(os.path.join(schema_basedir, schema))
  File "/usr/local/lib/python3.6/dist-packages/dtschema/lib.py", line 108, in do_load
    return yaml.load(tmp)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/main.py", line 343, in load
    return constructor.get_single_data()
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 113, in get_single_data
    return self.construct_document(node)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 123, in construct_document
    for _dummy in generator:
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 723, in construct_yaml_map
    value = self.construct_mapping(node)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 440, in construct_mapping
    return BaseConstructor.construct_mapping(self, node, deep=deep)
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 257, in construct_mapping
    if self.check_mapping_key(node, key_node, mapping, key, value):
  File "/usr/local/lib/python3.6/dist-packages/ruamel/yaml/constructor.py", line 295, in check_mapping_key
    raise DuplicateKeyError(*args)
ruamel.yaml.constructor.DuplicateKeyError: while constructing a mapping
  in "<unicode string>", line 5, column 1
found duplicate key "properties" with value "{}" (original value: "{}")
  in "<unicode string>", line 17, column 1

To suppress this check see:
    http://yaml.readthedocs.io/en/latest/api.html#duplicate-keys

Duplicate keys will become an error in future releases, and are errors
by default when using the new API.

Documentation/devicetree/bindings/Makefile:45: recipe for target 'Documentation/devicetree/bindings/processed-schema.yaml' failed
make[1]: *** [Documentation/devicetree/bindings/processed-schema.yaml] Error 123
make[1]: *** Deleting file 'Documentation/devicetree/bindings/processed-schema.yaml'
Makefile:1300: recipe for target 'dt_binding_check' failed
make: *** [dt_binding_check] Error 2

See https://patchwork.ozlabs.org/patch/1290443

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure dt-schema is up to date:

pip3 install git+https://github.com/devicetree-org/dt-schema.git@master --upgrade

Please check and re-submit.


^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH 01/19] dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device
  2020-05-14 14:59 ` [PATCH 01/19] dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device Kishon Vijay Abraham I
  2020-05-15  2:38   ` Rob Herring
@ 2020-05-22  5:53   ` Kishon Vijay Abraham I
  1 sibling, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-22  5:53 UTC (permalink / raw)
  To: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Rob Herring
  Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-pci, linux-doc,
	linux-kernel, devicetree, linux-ntb

Hi RobH,

On 5/14/2020 8:29 PM, Kishon Vijay Abraham I wrote:
> Add device tree schema for PCI endpoint function bus to which
> endpoint function devices should be attached. Then add device tree
> schema for PCI endpoint function device to include bindings thats
> generic to all endpoint functions. Finally add device tree schema
> for PCI endpoint NTB function device by including the generic
> device tree schema for PCIe endpoint function.
> 
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  .../bindings/pci/endpoint/pci-epf-bus.yaml    | 42 +++++++++++
>  .../bindings/pci/endpoint/pci-epf-device.yaml | 69 +++++++++++++++++++
>  .../bindings/pci/endpoint/pci-epf-ntb.yaml    | 68 ++++++++++++++++++
>  3 files changed, 179 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml
>  create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml
>  create mode 100644 Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml
> new file mode 100644
> index 000000000000..1c504f2e85e4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-bus.yaml
> @@ -0,0 +1,42 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pci/endpoint/pci-epf-bus.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: PCI Endpoint Function Bus
> +
> +maintainers:
> +  - Kishon Vijay Abraham I <kishon@ti.com>
> +
> +properties:
> +  compatible:
> +    const: pci-epf-bus
> +
> +patternProperties:
> +  "^func@[0-9a-f]+$":
> +    type: object
> +    description: |
> +      PCI Endpoint Function Bus node should have subnodes for each of
> +      the implemented endpoint function. It should follow the bindings
> +      specified for endpoint function in
> +      Documentation/devicetree/bindings/pci/endpoint/
> +
> +examples:
> +  - |
> +    epf_bus {
> +      compatible = "pci-epf-bus";
> +
> +      func@0 {
> +        compatible = "pci-epf-ntb";
> +        epcs = <&pcie0_ep>, <&pcie1_ep>;
> +        epc-names = "primary", "secondary";
> +        reg = <0>;

I'm not sure how to represent "reg" property properly for cases like this where
it represents ID and not a memory resource. I seem to get warning for
"reg_format" even after adding address-cells and size-cells property in
epf_bus. Can you give some hints here please?

> +        epf,vendor-id = /bits/ 16 <0x104c>;

I want to make vendor-id and device-id as 16 bits from the beginning at-least
for PCIe endpoint. So I'm prefixing these properties with "epf,". However I get
this "do not match any of the regexes:". Can we add "epf" as a standard prefix?

Thanks
Kishon
> +        epf,device-id = /bits/ 16 <0xb00d>;
> +        num-mws = <4>;
> +        mws-size = <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>;
> +      };
> +    };
> +...
> diff --git a/Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml
> new file mode 100644
> index 000000000000..cee72864c8ca
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-device.yaml
> @@ -0,0 +1,69 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pci/endpoint/pci-epf-device.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: PCI Endpoint Function Device
> +
> +maintainers:
> +  - Kishon Vijay Abraham I <kishon@ti.com>
> +
> +properties:
> +  compatible:
> +    const: pci-epf-bus
> +
> +properties:
> +  $nodename:
> +    pattern: "^func@"
> +
> +  epcs:
> +    description:
> +      Phandle to the endpoint controller device. Should have "2" entries for
> +      NTB endpoint function and "1" entry for others.
> +    minItems: 1
> +    maxItems: 2
> +
> +  epc-names:
> +    description:
> +      Must contain an entry for each entry in "epcs" when "epcs" have more than
> +      one entry.
> +
> +  reg:
> +    maxItems: 0
> +    description: Must contain the index number of the function.
> +
> +  epf,vendor-id:
> +    description:
> +      The PCI vendor ID
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint16
> +
> +  epf,device-id:
> +    description:
> +      The PCI device ID
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint16
> +
> +  epf,baseclass-code:
> +    description: Code to classify the type of operation the function performs
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint8
> +
> +  epf,subclass-code:
> +    description:
> +      Specifies a base class sub-class, which identifies more specifically the
> +      operation of the Function
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint8
> +
> +  epf,subsys-vendor-id:
> +    description: Code to identify vendor of the add-in card or subsystem
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint16
> +
> +  epf,subsys-id:
> +    description: Code to specify an id that is specific to a vendor
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint16
> diff --git a/Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml
> new file mode 100644
> index 000000000000..92c2e522b9e5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/endpoint/pci-epf-ntb.yaml
> @@ -0,0 +1,68 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pci/endpoint/pci-epf-ntb.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: PCI Endpoint NTB Function Device
> +
> +maintainers:
> +  - Kishon Vijay Abraham I <kishon@ti.com>
> +
> +allOf:
> +  - $ref: "pci-epf-device.yaml#"
> +
> +properties:
> +  compatible:
> +    const: pci-epf-ntb
> +
> +  epcs:
> +    minItems: 2
> +    maxItems: 2
> +
> +  epc-names:
> +    items:
> +      - const: primary
> +      - const: secondary
> +
> +  num-mws:
> +    description:
> +      Specify the number of memory windows
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint8
> +    minimum: 1
> +    maximum: 4
> +
> +  mws-size:
> +    description:
> +      List of 'num-mws' entries containing size of each memory window.
> +    minItems: 1
> +    maxItems: 4
> +
> +required:
> +  - compatible
> +  - epcs
> +  - epc-names
> +  - epf,vendor-id
> +  - epf,device-id
> +  - num-mws
> +  - mws-size
> +
> +examples:
> +  - |
> +    epf_bus {
> +      compatible = "pci-epf-bus";
> +
> +      func@0 {
> +        compatible = "pci-epf-ntb";
> +        reg = <0>;
> +        epcs = <&pcie0_ep>, <&pcie1_ep>;
> +        epc-names = "primary", "secondary";
> +        epf,vendor-id = /bits/ 16 <0x104c>;
> +        epf,device-id = /bits/ 16 <0xb00d>;
> +        num-mws = <4>;
> +        mws-size = <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>;
> +      };
> +    };
> +...
> 

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH 00/19] Implement NTB Controller using multiple PCI EP
  2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
                   ` (18 preceding siblings ...)
  2020-05-14 14:59 ` [PATCH 19/19] NTB: ntb_perf/ntb_tool: Use PCI device for dma_alloc_coherent() Kishon Vijay Abraham I
@ 2020-05-22 16:11 ` Rob Herring
  2020-05-23  1:47   ` Kishon Vijay Abraham I
  19 siblings, 1 reply; 24+ messages in thread
From: Rob Herring @ 2020-05-22 16:11 UTC (permalink / raw)
  To: Kishon Vijay Abraham I
  Cc: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Greg Kroah-Hartman,
	Jonathan Corbet, PCI, Linux Doc Mailing List, linux-kernel,
	devicetree, linux-ntb

On Thu, May 14, 2020 at 8:59 AM Kishon Vijay Abraham I <kishon@ti.com> wrote:
>
> This series is about implementing SW defined NTB using
> multiple endpoint instances. This series has been tested using
> 2 endpoint instances in J7 connected to two DRA7 boards. However there
> is nothing platform specific for the NTB functionality.
>
> This was presented in Linux Plumbers Conference. The presentation
> can be found @ [1]

I'd like to know why putting this into DT is better than configfs.
Does it solve some problem? Doing things in userspace is so much
easier and more flexible than modifying and updating a DT.

I don't really think the PCI endpoint stuff is mature enough to be
putting into DT either.

Rob

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH 00/19] Implement NTB Controller using multiple PCI EP
  2020-05-22 16:11 ` [PATCH 00/19] Implement NTB Controller using multiple PCI EP Rob Herring
@ 2020-05-23  1:47   ` Kishon Vijay Abraham I
  0 siblings, 0 replies; 24+ messages in thread
From: Kishon Vijay Abraham I @ 2020-05-23  1:47 UTC (permalink / raw)
  To: Rob Herring
  Cc: Lorenzo Pieralisi, Arnd Bergmann, Jon Mason, Dave Jiang,
	Allen Hubbe, Tom Joseph, Bjorn Helgaas, Greg Kroah-Hartman,
	Jonathan Corbet, PCI, Linux Doc Mailing List, linux-kernel,
	devicetree, linux-ntb

Hi Rob,

On 5/22/2020 9:41 PM, Rob Herring wrote:
> On Thu, May 14, 2020 at 8:59 AM Kishon Vijay Abraham I <kishon@ti.com> wrote:
>>
>> This series is about implementing SW defined NTB using
>> multiple endpoint instances. This series has been tested using
>> 2 endpoint instances in J7 connected to two DRA7 boards. However there
>> is nothing platform specific for the NTB functionality.
>>
>> This was presented in Linux Plumbers Conference. The presentation
>> can be found @ [1]
> 
> I'd like to know why putting this into DT is better than configfs.
> Does it solve some problem? Doing things in userspace is so much
> easier and more flexible than modifying and updating a DT.

It's a lot cleaner to have an endpoint function bound to two different endpoint
controller using device tree than configfs.

+    epf_bus {
+      compatible = "pci-epf-bus";
+
+      func@0 {
+        compatible = "pci-epf-ntb";
+        epcs = <&pcie0_ep>, <&pcie1_ep>;
+        epc-names = "primary", "secondary";
+        reg = <0>;
+        epf,vendor-id = /bits/ 16 <0x104c>;
+        epf,device-id = /bits/ 16 <0xb00d>;
+        num-mws = <4>;
+        mws-size = <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>, <0x0 0x100000>;
+      };

For device tree, just using phandles is enough and the driver can easily parse
DT to get EPCs bound to the endpoint function
+        epcs = <&pcie0_ep>, <&pcie1_ep>;
+        epc-names = "primary", "secondary";

This would be
ln -s functions/pci-epf-ntb/func1 controllers/2900000.pcie-ep/
ln -s functions/pci-epf-ntb/func1 controllers/2910000.pcie-ep/

pci_epc_epf_link() should then maintain the order of EPC bound to EPF and
designate one as PRIMARY_INTERFACE and the second as SECONDARY_INTERFACE.
pci_epf_bind() should be made to behave differently for NTB case.

While the standard properties (like vendorid, deviceid) has configfs entries,
additional logic would be required for adding function specific fields like
num-mws and mws-size above.

While all this support could be added in configfs, it looks simpler to
represent then in DT.

> 
> I don't really think the PCI endpoint stuff is mature enough to be
> putting into DT either.

I think this will anyways come when we have to export real HW peripherals to
the remote HOST using EP controller.

Thanks
Kishon

^ permalink raw reply	[flat|nested] 24+ messages in thread

end of thread, other threads:[~2020-05-23  1:48 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-05-14 14:59 [PATCH 00/19] Implement NTB Controller using multiple PCI EP Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 01/19] dt-bindings: PCI: Endpoint: Add DT bindings for PCI EPF NTB Device Kishon Vijay Abraham I
2020-05-15  2:38   ` Rob Herring
2020-05-22  5:53   ` Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 02/19] Documentation: PCI: Add specification for the *PCI NTB* function device Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 03/19] PCI: endpoint: Add API to get reference to EPC from device-tree Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 04/19] PCI: endpoint: Add API to create EPF device from device tree Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 05/19] PCI: endpoint: Add "pci-epf-bus" driver Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 06/19] PCI: endpoint: Make *_get_first_free_bar() take into account 64 bit BAR Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 07/19] PCI: endpoint: Add helper API to get the 'next' unreserved BAR Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 08/19] PCI: endpoint: Make *_free_bar() to return error codes on failure Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 09/19] PCI: endpoint: Remove unused pci_epf_match_device() Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 10/19] PCI: endpoint: Make pci_epf_driver ops optional Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 11/19] PCI: endpoint: Add helper API to populate header with values from DT Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 12/19] PCI: endpoint: Add support to associate secondary EPC with EPF Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 13/19] PCI: endpoint: Add pci_epc_ops to map MSI irq Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 14/19] PCI: cadence: Implement ->msi_map_irq() ops Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 15/19] PCI: endpoint: Add EP function driver to provide NTB functionality Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 16/19] PCI: Add TI J721E device to pci ids Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 17/19] NTB: Add support for EPF PCI-Express Non-Transparent Bridge Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 18/19] NTB: tool: Enable the NTB/PCIe link on the local or remote side of bridge Kishon Vijay Abraham I
2020-05-14 14:59 ` [PATCH 19/19] NTB: ntb_perf/ntb_tool: Use PCI device for dma_alloc_coherent() Kishon Vijay Abraham I
2020-05-22 16:11 ` [PATCH 00/19] Implement NTB Controller using multiple PCI EP Rob Herring
2020-05-23  1:47   ` Kishon Vijay Abraham I

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