Merge tag 'driver-core-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here's the "big" driver core update for 4.7-rc1.

  Mostly just debugfs changes, the long-known and messy races with
  removing debugfs files should be fixed thanks to the great work of
  Nicolai Stange.  We also have some isa updates in here (the x86
  maintainers told me to take it through this tree), a new warning when
  we run out of dynamic char major numbers, and a few other assorted
  changes, details in the shortlog.

  All have been in linux-next for some time with no reported issues"

* tag 'driver-core-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (32 commits)
  Revert "base: dd: don't remove driver_data in -EPROBE_DEFER case"
  gpio: ws16c48: Utilize the ISA bus driver
  gpio: 104-idio-16: Utilize the ISA bus driver
  gpio: 104-idi-48: Utilize the ISA bus driver
  gpio: 104-dio-48e: Utilize the ISA bus driver
  watchdog: ebc-c384_wdt: Utilize the ISA bus driver
  iio: stx104: Utilize the module_isa_driver and max_num_isa_dev macros
  iio: stx104: Add X86 dependency to STX104 Kconfig option
  Documentation: Add ISA bus driver documentation
  isa: Implement the max_num_isa_dev macro
  isa: Implement the module_isa_driver macro
  pnp: pnpbios: Add explicit X86_32 dependency to PNPBIOS
  isa: Decouple X86_32 dependency from the ISA Kconfig option
  driver-core: use 'dev' argument in dev_dbg_ratelimited stub
  base: dd: don't remove driver_data in -EPROBE_DEFER case
  kernfs: Move faulting copy_user operations outside of the mutex
  devcoredump: add scatterlist support
  debugfs: unproxify files created through debugfs_create_u32_array()
  debugfs: unproxify files created through debugfs_create_blob()
  debugfs: unproxify files created through debugfs_create_bool()
  ...

2 files changed, 149 insertions, 58 deletions

diff --git a/Documentation/devices.txt b/Documentation/devices.txt
index 87b4c5e82d39..4035eca87144 100644
--- a/Documentation/devices.txt
+++ b/Documentation/devices.txt
@@ -1,20 +1,17 @@
 
-		    LINUX ALLOCATED DEVICES (2.6+ version)
-
-	     Maintained by Alan Cox <device@lanana.org>
-
-		      Last revised: 6th April 2009
+		    LINUX ALLOCATED DEVICES (4.x+ version)
 
 This list is the Linux Device List, the official registry of allocated
 device numbers and /dev directory nodes for the Linux operating
 system.
 
-The latest version of this list is available from
-http://www.lanana.org/docs/device-list/ or
-ftp://ftp.kernel.org/pub/linux/docs/device-list/.  This version may be
-newer than the one distributed with the Linux kernel.
-
-The LaTeX version of this document is no longer maintained.
+The LaTeX version of this document is no longer maintained, nor is
+the document that used to reside at lanana.org.  This version in the
+mainline Linux kernel is the master document.  Updates shall be sent
+as patches to the kernel maintainers (see the SubmittingPatches document).
+Specifically explore the sections titled "CHAR and MISC DRIVERS", and
+"BLOCK LAYER" in the MAINTAINERS file to find the right maintainers
+to involve for character and block devices.
 
 This document is included by reference into the Filesystem Hierarchy
 Standard (FHS).	 The FHS is available from http://www.pathname.com/fhs/.
@@ -23,60 +20,33 @@ Allocations marked (68k/Amiga) apply to Linux/68k on the Amiga
 platform only.	Allocations marked (68k/Atari) apply to Linux/68k on
 the Atari platform only.
 
-The symbol {2.6} means the allocation is obsolete and scheduled for
-removal once kernel version 2.6 (or equivalent) is released. Some of these
-allocations have already been removed.
-
-This document is in the public domain.	The author requests, however,
+This document is in the public domain.	The authors requests, however,
 that semantically altered versions are not distributed without
-permission of the author, assuming the author can be contacted without
+permission of the authors, assuming the authors can be contacted without
 an unreasonable effort.
 
-In particular, please don't sent patches for this list to Linus, at
-least not without contacting me first.
-
-I do not have any information about these devices beyond what appears
-on this list.  Any such information requests will be deleted without
-reply.
-
 
 	  **** DEVICE DRIVERS AUTHORS PLEASE READ THIS ****
 
-To have a major number allocated, or a minor number in situations
-where that applies (e.g. busmice), please contact me with the
-appropriate device information.	 Also, if you have additional
-information regarding any of the devices listed below, or if I have
-made a mistake, I would greatly appreciate a note.
-
-I do, however, make a few requests about the nature of your report.
-This is necessary for me to be able to keep this list up to date and
-correct in a timely manner.  First of all, *please* send it to the
-correct address... <device@lanana.org>.  I receive hundreds of email
-messages a day, so mail sent to other addresses may very well get lost
-in the avalanche.  Please put in a descriptive subject, so I can find
-your mail again should I need to.  Too many people send me email
-saying just "device number request" in the subject.
-
-Second, please include a description of the device *in the same format
-as this list*.	The reason for this is that it is the only way I have
-found to ensure I have all the requisite information to publish your
-device and avoid conflicts.
+Linux now has extensive support for dynamic allocation of device numbering
+and can use sysfs and udev (systemd) to handle the naming needs. There are
+still some exceptions in the serial and boot device area. Before asking
+for a device number make sure you actually need one.
 
-Third, please don't assume that the distributed version of the list is
-up to date.  Due to the number of registrations I have to maintain it
-in "batch mode", so there is likely additional registrations that
-haven't been listed yet.
+To have a major number allocated, or a minor number in situations
+where that applies (e.g. busmice), please submit a patch and send to
+the authors as indicated above.
 
-Fourth, remember that Linux now has extensive support for dynamic allocation
-of device numbering and can use sysfs and udev to handle the naming needs.
-There are still some exceptions in the serial and boot device area. Before
-asking for a device number make sure you actually need one.
+Keep the description of the device *in the same format
+as this list*.	The reason for this is that it is the only way we have
+found to ensure we have all the requisite information to publish your
+device and avoid conflicts.
 
-Finally, sometimes I have to play "namespace police."  Please don't be
-offended.  I often get submissions for /dev names that would be bound
-to cause conflicts down the road.  I am trying to avoid getting in a
+Finally, sometimes we have to play "namespace police."  Please don't be
+offended.  We often get submissions for /dev names that would be bound
+to cause conflicts down the road.  We are trying to avoid getting in a
 situation where we would have to suffer an incompatible forward
-change.  Therefore, please consult with me *before* you make your
+change.  Therefore, please consult with us *before* you make your
 device names and numbers in any way public, at least to the point
 where it would be at all difficult to get them changed.
 
@@ -3099,9 +3069,9 @@ Your cooperation is appreciated.
 		129 = /dev/ipath_sma    Device used by Subnet Management Agent
 		130 = /dev/ipath_diag   Device used by diagnostics programs
 
-234-239		UNASSIGNED
-
-240-254 char	LOCAL/EXPERIMENTAL USE
+234-254	char	RESERVED FOR DYNAMIC ASSIGNMENT
+		Character devices that request a dynamic allocation of major number will
+		take numbers starting from 254 and downward.
 
 240-254 block	LOCAL/EXPERIMENTAL USE
 		Allocated for local/experimental use.  For devices not
diff --git a/Documentation/isa.txt b/Documentation/isa.txt
new file mode 100644
index 000000000000..f232c26a40be
--- /dev/null
+++ b/Documentation/isa.txt
@@ -0,0 +1,121 @@
+ISA Drivers
+-----------
+
+The following text is adapted from the commit message of the initial
+commit of the ISA bus driver authored by Rene Herman.
+
+During the recent "isa drivers using platform devices" discussion it was
+pointed out that (ALSA) ISA drivers ran into the problem of not having
+the option to fail driver load (device registration rather) upon not
+finding their hardware due to a probe() error not being passed up
+through the driver model. In the course of that, I suggested a separate
+ISA bus might be best; Russell King agreed and suggested this bus could
+use the .match() method for the actual device discovery.
+
+The attached does this. For this old non (generically) discoverable ISA
+hardware only the driver itself can do discovery so as a difference with
+the platform_bus, this isa_bus also distributes match() up to the
+driver.
+
+As another difference: these devices only exist in the driver model due
+to the driver creating them because it might want to drive them, meaning
+that all device creation has been made internal as well.
+
+The usage model this provides is nice, and has been acked from the ALSA
+side by Takashi Iwai and Jaroslav Kysela. The ALSA driver module_init's
+now (for oldisa-only drivers) become:
+
+static int __init alsa_card_foo_init(void)
+{
+	return isa_register_driver(&snd_foo_isa_driver, SNDRV_CARDS);
+}
+
+static void __exit alsa_card_foo_exit(void)
+{
+	isa_unregister_driver(&snd_foo_isa_driver);
+}
+
+Quite like the other bus models therefore. This removes a lot of
+duplicated init code from the ALSA ISA drivers.
+
+The passed in isa_driver struct is the regular driver struct embedding a
+struct device_driver, the normal probe/remove/shutdown/suspend/resume
+callbacks, and as indicated that .match callback.
+
+The "SNDRV_CARDS" you see being passed in is a "unsigned int ndev"
+parameter, indicating how many devices to create and call our methods
+with.
+
+The platform_driver callbacks are called with a platform_device param;
+the isa_driver callbacks are being called with a "struct device *dev,
+unsigned int id" pair directly -- with the device creation completely
+internal to the bus it's much cleaner to not leak isa_dev's by passing
+them in at all. The id is the only thing we ever want other then the
+struct device * anyways, and it makes for nicer code in the callbacks as
+well.
+
+With this additional .match() callback ISA drivers have all options. If
+ALSA would want to keep the old non-load behaviour, it could stick all
+of the old .probe in .match, which would only keep them registered after
+everything was found to be present and accounted for. If it wanted the
+behaviour of always loading as it inadvertently did for a bit after the
+changeover to platform devices, it could just not provide a .match() and
+do everything in .probe() as before.
+
+If it, as Takashi Iwai already suggested earlier as a way of following
+the model from saner buses more closely, wants to load when a later bind
+could conceivably succeed, it could use .match() for the prerequisites
+(such as checking the user wants the card enabled and that port/irq/dma
+values have been passed in) and .probe() for everything else. This is
+the nicest model.
+
+To the code...
+
+This exports only two functions; isa_{,un}register_driver().
+
+isa_register_driver() register's the struct device_driver, and then
+loops over the passed in ndev creating devices and registering them.
+This causes the bus match method to be called for them, which is:
+
+int isa_bus_match(struct device *dev, struct device_driver *driver)
+{
+          struct isa_driver *isa_driver = to_isa_driver(driver);
+
+          if (dev->platform_data == isa_driver) {
+                  if (!isa_driver->match ||
+                          isa_driver->match(dev, to_isa_dev(dev)->id))
+                          return 1;
+                  dev->platform_data = NULL;
+          }
+          return 0;
+}
+
+The first thing this does is check if this device is in fact one of this
+driver's devices by seeing if the device's platform_data pointer is set
+to this driver. Platform devices compare strings, but we don't need to
+do that with everything being internal, so isa_register_driver() abuses
+dev->platform_data as a isa_driver pointer which we can then check here.
+I believe platform_data is available for this, but if rather not, moving
+the isa_driver pointer to the private struct isa_dev is ofcourse fine as
+well.
+
+Then, if the the driver did not provide a .match, it matches. If it did,
+the driver match() method is called to determine a match.
+
+If it did _not_ match, dev->platform_data is reset to indicate this to
+isa_register_driver which can then unregister the device again.
+
+If during all this, there's any error, or no devices matched at all
+everything is backed out again and the error, or -ENODEV, is returned.
+
+isa_unregister_driver() just unregisters the matched devices and the
+driver itself.
+
+module_isa_driver is a helper macro for ISA drivers which do not do
+anything special in module init/exit. This eliminates a lot of
+boilerplate code. Each module may only use this macro once, and calling
+it replaces module_init and module_exit.
+
+max_num_isa_dev is a macro to determine the maximum possible number of
+ISA devices which may be registered in the I/O port address space given
+the address extent of the ISA devices.