Merge tag 'char-misc-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the "big" char and misc driver patches for 4.18-rc1.

  It's not a lot of stuff here, but there are some highlights:

   - coreboot driver updates

   - soundwire driver updates

   - android binder updates

   - fpga big sync, mostly documentation

   - lots of minor driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (81 commits)
  vmw_balloon: fixing double free when batching mode is off
  MAINTAINERS: Add driver-api/fpga path
  fpga: clarify that unregister functions also free
  documentation: fpga: move fpga-region.txt to driver-api
  documentation: fpga: add bridge document to driver-api
  documentation: fpga: move fpga-mgr.txt to driver-api
  Documentation: fpga: move fpga overview to driver-api
  fpga: region: kernel-doc fixes
  fpga: bridge: kernel-doc fixes
  fpga: mgr: kernel-doc fixes
  fpga: use SPDX
  fpga: region: change api, add fpga_region_create/free
  fpga: bridge: change api, don't use drvdata
  fpga: manager: change api, don't use drvdata
  fpga: region: don't use drvdata in common fpga code
  Drivers: hv: vmbus: Removed an unnecessary cast from void *
  ver_linux: Drop redundant calls to system() to test if file is readable
  ver_linux: Move stderr redirection from function parameter to function body
  misc: IBM Virtual Management Channel Driver (VMC)
  rpmsg: Correct support for MODULE_DEVICE_TABLE()
  ...

5 files changed, 438 insertions, 0 deletions

diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
new file mode 100644
index 000000000000..2c2aaca894bf
--- /dev/null
+++ b/Documentation/driver-api/fpga/fpga-bridge.rst
@@ -0,0 +1,49 @@
+FPGA Bridge
+===========
+
+API to implement a new FPGA bridge
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/linux/fpga/fpga-bridge.h
+   :functions: fpga_bridge
+
+.. kernel-doc:: include/linux/fpga/fpga-bridge.h
+   :functions: fpga_bridge_ops
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_create
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_free
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_register
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_unregister
+
+API to control an FPGA bridge
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You probably won't need these directly.  FPGA regions should handle this.
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: of_fpga_bridge_get
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_get
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_put
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_get_to_list
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: of_fpga_bridge_get_to_list
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_enable
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_disable
diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
new file mode 100644
index 000000000000..bcf2dd24e179
--- /dev/null
+++ b/Documentation/driver-api/fpga/fpga-mgr.rst
@@ -0,0 +1,220 @@
+FPGA Manager
+============
+
+Overview
+--------
+
+The FPGA manager core exports a set of functions for programming an FPGA with
+an image.  The API is manufacturer agnostic.  All manufacturer specifics are
+hidden away in a low level driver which registers a set of ops with the core.
+The FPGA image data itself is very manufacturer specific, but for our purposes
+it's just binary data.  The FPGA manager core won't parse it.
+
+The FPGA image to be programmed can be in a scatter gather list, a single
+contiguous buffer, or a firmware file.  Because allocating contiguous kernel
+memory for the buffer should be avoided, users are encouraged to use a scatter
+gather list instead if possible.
+
+The particulars for programming the image are presented in a structure (struct
+fpga_image_info).  This struct contains parameters such as pointers to the
+FPGA image as well as image-specific particulars such as whether the image was
+built for full or partial reconfiguration.
+
+How to support a new FPGA device
+--------------------------------
+
+To add another FPGA manager, write a driver that implements a set of ops.  The
+probe function calls fpga_mgr_register(), such as::
+
+        static const struct fpga_manager_ops socfpga_fpga_ops = {
+                .write_init = socfpga_fpga_ops_configure_init,
+                .write = socfpga_fpga_ops_configure_write,
+                .write_complete = socfpga_fpga_ops_configure_complete,
+                .state = socfpga_fpga_ops_state,
+        };
+
+        static int socfpga_fpga_probe(struct platform_device *pdev)
+        {
+                struct device *dev = &pdev->dev;
+                struct socfpga_fpga_priv *priv;
+                struct fpga_manager *mgr;
+                int ret;
+
+                priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+                if (!priv)
+                        return -ENOMEM;
+
+                /*
+                 * do ioremaps, get interrupts, etc. and save
+                 * them in priv
+                 */
+
+                mgr = fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
+                                      &socfpga_fpga_ops, priv);
+                if (!mgr)
+                        return -ENOMEM;
+
+                platform_set_drvdata(pdev, mgr);
+
+                ret = fpga_mgr_register(mgr);
+                if (ret)
+                        fpga_mgr_free(mgr);
+
+                return ret;
+        }
+
+        static int socfpga_fpga_remove(struct platform_device *pdev)
+        {
+                struct fpga_manager *mgr = platform_get_drvdata(pdev);
+
+                fpga_mgr_unregister(mgr);
+
+                return 0;
+        }
+
+
+The ops will implement whatever device specific register writes are needed to
+do the programming sequence for this particular FPGA.  These ops return 0 for
+success or negative error codes otherwise.
+
+The programming sequence is::
+ 1. .write_init
+ 2. .write or .write_sg (may be called once or multiple times)
+ 3. .write_complete
+
+The .write_init function will prepare the FPGA to receive the image data.  The
+buffer passed into .write_init will be atmost .initial_header_size bytes long,
+if the whole bitstream is not immediately available then the core code will
+buffer up at least this much before starting.
+
+The .write function writes a buffer to the FPGA. The buffer may be contain the
+whole FPGA image or may be a smaller chunk of an FPGA image.  In the latter
+case, this function is called multiple times for successive chunks. This interface
+is suitable for drivers which use PIO.
+
+The .write_sg version behaves the same as .write except the input is a sg_table
+scatter list. This interface is suitable for drivers which use DMA.
+
+The .write_complete function is called after all the image has been written
+to put the FPGA into operating mode.
+
+The ops include a .state function which will read the hardware FPGA manager and
+return a code of type enum fpga_mgr_states.  It doesn't result in a change in
+hardware state.
+
+How to write an image buffer to a supported FPGA
+------------------------------------------------
+
+Some sample code::
+
+        #include <linux/fpga/fpga-mgr.h>
+
+        struct fpga_manager *mgr;
+        struct fpga_image_info *info;
+        int ret;
+
+        /*
+         * Get a reference to FPGA manager.  The manager is not locked, so you can
+         * hold onto this reference without it preventing programming.
+         *
+         * This example uses the device node of the manager.  Alternatively, use
+         * fpga_mgr_get(dev) instead if you have the device.
+         */
+        mgr = of_fpga_mgr_get(mgr_node);
+
+        /* struct with information about the FPGA image to program. */
+        info = fpga_image_info_alloc(dev);
+
+        /* flags indicates whether to do full or partial reconfiguration */
+        info->flags = FPGA_MGR_PARTIAL_RECONFIG;
+
+        /*
+         * At this point, indicate where the image is. This is pseudo-code; you're
+         * going to use one of these three.
+         */
+        if (image is in a scatter gather table) {
+
+                info->sgt = [your scatter gather table]
+
+        } else if (image is in a buffer) {
+
+                info->buf = [your image buffer]
+                info->count = [image buffer size]
+
+        } else if (image is in a firmware file) {
+
+                info->firmware_name = devm_kstrdup(dev, firmware_name, GFP_KERNEL);
+
+        }
+
+        /* Get exclusive control of FPGA manager */
+        ret = fpga_mgr_lock(mgr);
+
+        /* Load the buffer to the FPGA */
+        ret = fpga_mgr_buf_load(mgr, &info, buf, count);
+
+        /* Release the FPGA manager */
+        fpga_mgr_unlock(mgr);
+        fpga_mgr_put(mgr);
+
+        /* Deallocate the image info if you're done with it */
+        fpga_image_info_free(info);
+
+API for implementing a new FPGA Manager driver
+----------------------------------------------
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+   :functions: fpga_manager
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+   :functions: fpga_manager_ops
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_create
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_free
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_register
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_unregister
+
+API for programming a FPGA
+--------------------------
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+   :functions: fpga_image_info
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+   :functions: fpga_mgr_states
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_image_info_alloc
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_image_info_free
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: of_fpga_mgr_get
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_get
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_put
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_lock
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_unlock
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+   :functions: fpga_mgr_states
+
+Note - use :c:func:`fpga_region_program_fpga()` instead of :c:func:`fpga_mgr_load()`
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_load
diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
new file mode 100644
index 000000000000..f89e4a311722
--- /dev/null
+++ b/Documentation/driver-api/fpga/fpga-region.rst
@@ -0,0 +1,102 @@
+FPGA Region
+===========
+
+Overview
+--------
+
+This document is meant to be an brief overview of the FPGA region API usage.  A
+more conceptual look at regions can be found in the Device Tree binding
+document [#f1]_.
+
+For the purposes of this API document, let's just say that a region associates
+an FPGA Manager and a bridge (or bridges) with a reprogrammable region of an
+FPGA or the whole FPGA.  The API provides a way to register a region and to
+program a region.
+
+Currently the only layer above fpga-region.c in the kernel is the Device Tree
+support (of-fpga-region.c) described in [#f1]_.  The DT support layer uses regions
+to program the FPGA and then DT to handle enumeration.  The common region code
+is intended to be used by other schemes that have other ways of accomplishing
+enumeration after programming.
+
+An fpga-region can be set up to know the following things:
+
+ * which FPGA manager to use to do the programming
+
+ * which bridges to disable before programming and enable afterwards.
+
+Additional info needed to program the FPGA image is passed in the struct
+fpga_image_info including:
+
+ * pointers to the image as either a scatter-gather buffer, a contiguous
+   buffer, or the name of firmware file
+
+ * flags indicating specifics such as whether the image if for partial
+   reconfiguration.
+
+How to program a FPGA using a region
+------------------------------------
+
+First, allocate the info struct::
+
+        info = fpga_image_info_alloc(dev);
+        if (!info)
+                return -ENOMEM;
+
+Set flags as needed, i.e.::
+
+        info->flags |= FPGA_MGR_PARTIAL_RECONFIG;
+
+Point to your FPGA image, such as::
+
+        info->sgt = &sgt;
+
+Add info to region and do the programming::
+
+        region->info = info;
+        ret = fpga_region_program_fpga(region);
+
+:c:func:`fpga_region_program_fpga()` operates on info passed in the
+fpga_image_info (region->info).  This function will attempt to:
+
+ * lock the region's mutex
+ * lock the region's FPGA manager
+ * build a list of FPGA bridges if a method has been specified to do so
+ * disable the bridges
+ * program the FPGA
+ * re-enable the bridges
+ * release the locks
+
+Then you will want to enumerate whatever hardware has appeared in the FPGA.
+
+How to add a new FPGA region
+----------------------------
+
+An example of usage can be seen in the probe function of [#f2]_.
+
+.. [#f1] ../devicetree/bindings/fpga/fpga-region.txt
+.. [#f2] ../../drivers/fpga/of-fpga-region.c
+
+API to program a FGPA
+---------------------
+
+.. kernel-doc:: drivers/fpga/fpga-region.c
+   :functions: fpga_region_program_fpga
+
+API to add a new FPGA region
+----------------------------
+
+.. kernel-doc:: include/linux/fpga/fpga-region.h
+   :functions: fpga_region
+
+.. kernel-doc:: drivers/fpga/fpga-region.c
+   :functions: fpga_region_create
+
+.. kernel-doc:: drivers/fpga/fpga-region.c
+   :functions: fpga_region_free
+
+.. kernel-doc:: drivers/fpga/fpga-region.c
+   :functions: fpga_region_register
+
+.. kernel-doc:: drivers/fpga/fpga-region.c
+   :functions: fpga_region_unregister
diff --git a/Documentation/driver-api/fpga/index.rst b/Documentation/driver-api/fpga/index.rst
new file mode 100644
index 000000000000..c51e5ebd544a
--- /dev/null
+++ b/Documentation/driver-api/fpga/index.rst
@@ -0,0 +1,13 @@
+==============
+FPGA Subsystem
+==============
+
+:Author: Alan Tull
+
+.. toctree::
+   :maxdepth: 2
+
+   intro
+   fpga-mgr
+   fpga-bridge
+   fpga-region
diff --git a/Documentation/driver-api/fpga/intro.rst b/Documentation/driver-api/fpga/intro.rst
new file mode 100644
index 000000000000..51cd81dbb4dc
--- /dev/null
+++ b/Documentation/driver-api/fpga/intro.rst
@@ -0,0 +1,54 @@
+Introduction
+============
+
+The FPGA subsystem supports reprogramming FPGAs dynamically under
+Linux.  Some of the core intentions of the FPGA subsystems are:
+
+* The FPGA subsystem is vendor agnostic.
+
+* The FPGA subsystem separates upper layers (userspace interfaces and
+  enumeration) from lower layers that know how to program a specific
+  FPGA.
+
+* Code should not be shared between upper and lower layers.  This
+  should go without saying.  If that seems necessary, there's probably
+  framework functionality that that can be added that will benefit
+  other users.  Write the linux-fpga mailing list and maintainers and
+  seek out a solution that expands the framework for broad reuse.
+
+* Generally, when adding code, think of the future.  Plan for re-use.
+
+The framework in the kernel is divided into:
+
+FPGA Manager
+------------
+
+If you are adding a new FPGA or a new method of programming a FPGA,
+this is the subsystem for you.  Low level FPGA manager drivers contain
+the knowledge of how to program a specific device.  This subsystem
+includes the framework in fpga-mgr.c and the low level drivers that
+are registered with it.
+
+FPGA Bridge
+-----------
+
+FPGA Bridges prevent spurious signals from going out of a FPGA or a
+region of a FPGA during programming.  They are disabled before
+programming begins and re-enabled afterwards.  An FPGA bridge may be
+actual hard hardware that gates a bus to a cpu or a soft ("freeze")
+bridge in FPGA fabric that surrounds a partial reconfiguration region
+of an FPGA.  This subsystem includes fpga-bridge.c and the low level
+drivers that are registered with it.
+
+FPGA Region
+-----------
+
+If you are adding a new interface to the FPGA framework, add it on top
+of a FPGA region to allow the most reuse of your interface.
+
+The FPGA Region framework (fpga-region.c) associates managers and
+bridges as reconfigurable regions.  A region may refer to the whole
+FPGA in full reconfiguration or to a partial reconfiguration region.
+
+The Device Tree FPGA Region support (of-fpga-region.c) handles
+reprogramming FPGAs when device tree overlays are applied.