Merge tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of driver core changes for 5.19-rc1.

  Lots of tiny driver core changes and cleanups happened this cycle, but
  the two major things are:

   - firmware_loader reorganization and additions including the ability
     to have XZ compressed firmware images and the ability for userspace
     to initiate the firmware load when it needs to, instead of being
     always initiated by the kernel. FPGA devices specifically want this
     ability to have their firmware changed over the lifetime of the
     system boot, and this allows them to work without having to come up
     with yet-another-custom-uapi interface for loading firmware for
     them.

   - physical location support added to sysfs so that devices that know
     this information, can tell userspace where they are located in a
     common way. Some ACPI devices already support this today, and more
     bus types should support this in the future.

  Smaller changes include:

   - driver_override api cleanups and fixes

   - error path cleanups and fixes

   - get_abi script fixes

   - deferred probe timeout changes.

  It's that last change that I'm the most worried about. It has been
  reported to cause boot problems for a number of systems, and I have a
  tested patch series that resolves this issue. But I didn't get it
  merged into my tree before 5.18-final came out, so it has not gotten
  any linux-next testing.

  I'll send the fixup patches (there are 2) as a follow-on series to this
  pull request.

  All have been tested in linux-next for weeks, with no reported issues
  other than the above-mentioned boot time-outs"

* tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
  driver core: fix deadlock in __device_attach
  kernfs: Separate kernfs_pr_cont_buf and rename_lock.
  topology: Remove unused cpu_cluster_mask()
  driver core: Extend deferred probe timeout on driver registration
  MAINTAINERS: add Russ Weight as a firmware loader maintainer
  driver: base: fix UAF when driver_attach failed
  test_firmware: fix end of loop test in upload_read_show()
  driver core: location: Add "back" as a possible output for panel
  driver core: location: Free struct acpi_pld_info *pld
  driver core: Add "*" wildcard support to driver_async_probe cmdline param
  driver core: location: Check for allocations failure
  arch_topology: Trace the update thermal pressure
  kernfs: Rename kernfs_put_open_node to kernfs_unlink_open_file.
  export: fix string handling of namespace in EXPORT_SYMBOL_NS
  rpmsg: use local 'dev' variable
  rpmsg: Fix calling device_lock() on non-initialized device
  firmware_loader: describe 'module' parameter of firmware_upload_register()
  firmware_loader: Move definitions from sysfs_upload.h to sysfs.h
  firmware_loader: Fix configs for sysfs split
  selftests: firmware: Add firmware upload selftests
  ...

1 files changed, 126 insertions, 0 deletions

diff --git a/Documentation/driver-api/firmware/fw_upload.rst b/Documentation/driver-api/firmware/fw_upload.rst
new file mode 100644
index 000000000000..76922591e446
--- /dev/null
+++ b/Documentation/driver-api/firmware/fw_upload.rst
@@ -0,0 +1,126 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===================
+Firmware Upload API
+===================
+
+A device driver that registers with the firmware loader will expose
+persistent sysfs nodes to enable users to initiate firmware updates for
+that device.  It is the responsibility of the device driver and/or the
+device itself to perform any validation on the data received. Firmware
+upload uses the same *loading* and *data* sysfs files described in the
+documentation for firmware fallback. It also adds additional sysfs files
+to provide status on the transfer of the firmware image to the device.
+
+Register for firmware upload
+============================
+
+A device driver registers for firmware upload by calling
+firmware_upload_register(). Among the parameter list is a name to
+identify the device under /sys/class/firmware. A user may initiate a
+firmware upload by echoing a 1 to the *loading* sysfs file for the target
+device. Next, the user writes the firmware image to the *data* sysfs
+file. After writing the firmware data, the user echos 0 to the *loading*
+sysfs file to signal completion. Echoing 0 to *loading* also triggers the
+transfer of the firmware to the lower-lever device driver in the context
+of a kernel worker thread.
+
+To use the firmware upload API, write a driver that implements a set of
+ops.  The probe function calls firmware_upload_register() and the remove
+function calls firmware_upload_unregister() such as::
+
+	static const struct fw_upload_ops m10bmc_ops = {
+		.prepare = m10bmc_sec_prepare,
+		.write = m10bmc_sec_write,
+		.poll_complete = m10bmc_sec_poll_complete,
+		.cancel = m10bmc_sec_cancel,
+		.cleanup = m10bmc_sec_cleanup,
+	};
+
+	static int m10bmc_sec_probe(struct platform_device *pdev)
+	{
+		const char *fw_name, *truncate;
+		struct m10bmc_sec *sec;
+		struct fw_upload *fwl;
+		unsigned int len;
+
+		sec = devm_kzalloc(&pdev->dev, sizeof(*sec), GFP_KERNEL);
+		if (!sec)
+			return -ENOMEM;
+
+		sec->dev = &pdev->dev;
+		sec->m10bmc = dev_get_drvdata(pdev->dev.parent);
+		dev_set_drvdata(&pdev->dev, sec);
+
+		fw_name = dev_name(sec->dev);
+		truncate = strstr(fw_name, ".auto");
+		len = (truncate) ? truncate - fw_name : strlen(fw_name);
+		sec->fw_name = kmemdup_nul(fw_name, len, GFP_KERNEL);
+
+		fwl = firmware_upload_register(sec->dev, sec->fw_name, &m10bmc_ops, sec);
+		if (IS_ERR(fwl)) {
+			dev_err(sec->dev, "Firmware Upload driver failed to start\n");
+			kfree(sec->fw_name);
+			return PTR_ERR(fwl);
+		}
+
+		sec->fwl = fwl;
+		return 0;
+	}
+
+	static int m10bmc_sec_remove(struct platform_device *pdev)
+	{
+		struct m10bmc_sec *sec = dev_get_drvdata(&pdev->dev);
+
+		firmware_upload_unregister(sec->fwl);
+		kfree(sec->fw_name);
+		return 0;
+	}
+
+firmware_upload_register
+------------------------
+.. kernel-doc:: drivers/base/firmware_loader/sysfs_upload.c
+   :identifiers: firmware_upload_register
+
+firmware_upload_unregister
+--------------------------
+.. kernel-doc:: drivers/base/firmware_loader/sysfs_upload.c
+   :identifiers: firmware_upload_unregister
+
+Firmware Upload Ops
+-------------------
+.. kernel-doc:: include/linux/firmware.h
+   :identifiers: fw_upload_ops
+
+Firmware Upload Progress Codes
+------------------------------
+The following progress codes are used internally by the firmware loader.
+Corresponding strings are reported through the status sysfs node that
+is described below and are documented in the ABI documentation.
+
+.. kernel-doc:: drivers/base/firmware_loader/sysfs_upload.h
+   :identifiers: fw_upload_prog
+
+Firmware Upload Error Codes
+---------------------------
+The following error codes may be returned by the driver ops in case of
+failure:
+
+.. kernel-doc:: include/linux/firmware.h
+   :identifiers: fw_upload_err
+
+Sysfs Attributes
+================
+
+In addition to the *loading* and *data* sysfs files, there are additional
+sysfs files to monitor the status of the data transfer to the target
+device and to determine the final pass/fail status of the transfer.
+Depending on the device and the size of the firmware image, a firmware
+update could take milliseconds or minutes.
+
+The additional sysfs files are:
+
+* status - provides an indication of the progress of a firmware update
+* error - provides error information for a failed firmware update
+* remaining_size - tracks the data transfer portion of an update
+* cancel - echo 1 to this file to cancel the update