WMI provides interface-specific GUIDs that are exported from modules as
modalises, but the core currently generates no events to trigger module
loading. This patch adds support for registering devices for each WMI GUID
and generating the appropriate uevent.

Based heavily on a patch by Carlos Corbacho (<carlos@strangeworlds.co.uk>).
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Tested-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Acked-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>

Linux/ACPI core files using internal.h all PREFIX "ACPI: ",
however, not all ACPI drivers use/want it -- and they
should not have to #undef PREFIX to define their own.

Add GPL commment to internal.h while we are there.

This does not change any actual console output,
asside from a whitespace fix.
Signed-off-by: NLen Brown <len.brown@intel.com>

Summary:
Kernel panic arise when stack protection is enabled, since strncat will
add a null terminating byte '\0'; So in functions
like this one (wmi_query_block):
        char wc[4]="WC";
	....
	strncat(method, block->object_id, 2);
        ...
the length of wc should be n+1 (wc[5]) or stack protection
fault will arise. This is not noticeable when stack protection is
disabled,but , isn't good either.
Config used: [CONFIG_CC_STACKPROTECTOR_ALL=y,
	      CONFIG_CC_STACKPROTECTOR=y]

Panic Trace
------------
       .... stack-protector: kernel stack corrupted in : fa7b182c
       2.6.30-rc8-obelisco-generic
       call_trace:
           [<c04a6c40>] ? panic+0x45/0xd9
	   [<c012925d>] ? __stack_chk_fail+0x1c/0x40
	   [<fa7b182c>] ? wmi_query_block+0x15a/0x162 [wmi]
	   [<fa7b182c>] ? wmi_query_block+0x15a/0x162 [wmi]
	   [<fa7e7000>] ? acer_wmi_init+0x00/0x61a [acer_wmi]
	   [<fa7e7135>] ? acer_wmi_init+0x135/0x61a [acer_wmi]
	   [<c0101159>] ? do_one_initcall+0x50+0x126

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13514Signed-off-by: NCostantino Leandro <lcostantino@gmail.com>
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Len Brown <len.brown@intel.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds a .notify() method.  The presence of .notify() causes
Linux/ACPI to manage event handlers and notify handlers on our behalf,
so we don't have to install and remove them ourselves.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
CC: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>

include/linux/pci-acpi.h:74:

typedef u32                 acpi_status;

result is unsigned, so an error returned by acpi_bus_register_driver()
will not be noticed.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

These are platform specific drivers that happen to use ACPI,
while drivers/acpi/ is for code that implements ACPI itself.
Signed-off-by: NLen Brown <len.brown@intel.com>

This patch is part of a larger patch series which will remove
the "char bus_id[20]" name string from struct device. The device
name is managed in the kobject anyway, and without any size
limitation, and just needlessly copied into "struct device".

To set and read the device name dev_name(dev) and dev_set_name(dev)
must be used. If your code uses static kobjects, which it shouldn't
do, "const char *init_name" can be used to statically provide the
name the registered device should have. At registration time, the
init_name field is cleared, to enforce the use of dev_name(dev) to
access the device name at a later time.

We need to get rid of all occurrences of bus_id in the entire tree
to be able to enable the new interface. Please apply this patch,
and possibly convert any remaining remaining occurrences of bus_id.

We want to submit a patch to -next, which will remove bus_id from
"struct device", to find the remaining pieces to convert, and finally
switch over to the new api, which will remove the 20 bytes array
and does no longer have a size limitation.
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-Off-By: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

The AE_BAD_ADDRESS exception code is now unused in ACPICA.
For linux, it's only used at wmi.c and acer-wmi.c.
I checked both wmi.c and acer-wmi.c, the AE_BAD_ADDRESS exception code
has no special meaning. The parent functions just call AE_SUCCESS() or
AE_FAILURE() to check the return status.
So it's safe to replace AE_BAD_ADDRESS with AE_ERROR.

Signed-off-by Lin Ming <ming.m.lin@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

According to the ACPI-WMI spec, event blocks may provide a function call
for enabling/disabling them. This patch adds support for making these
calls when registering or removing notifications. Without this, my Dell
firmware provides no data in the event notification.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>

Although the necessary data structure was set up, it was never actually
passed in, so data block calls have only been working by sheer chance.

(On Acer laptops. the data block methods we've been calling never look at
the instance value, hence acer-wmi never triggered this before).

f3454ae8 brought this to light.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Acer violate the ACPI-WMI spec by declaring some of their data blocks as
expensive, but with no corresponding WCxx method. There is already some
workaround code in to handle the initial WCxx call (we just ignore a
failure here); but we need to properly check if the second, "clean up",
WCxx call is actually needed or not, rather than fail simply because it
isn't there.
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Even if we don't want to register the WMI driver, we should initialize
the wmi_blocks list to be empty, since we don't want the wmi helper
functions to oops just because that basic list has not even been set up.

With this, "find_guid()" will happily return "not found" rather than
oopsing all over the place, and the callers will then just automatically
return false or AE_NOT_FOUND as appropriate.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The following is an implementation of the Windows Management
Instrumentation (WMI) ACPI interface mapper (PNP0C14).

What it does:

Parses the _WDG method and exports functions to process WMI method calls,
data block query/ set commands (both based on GUID) and does basic event
handling.

How: WMI presents an in kernel interface here (essentially, a minimal
wrapper around ACPI)

(const char *guid assume the 36 character ASCII representation of
a GUID - e.g. 67C3371D-95A3-4C37-BB61-DD47B491DAAB)

wmi_evaluate_method(const char *guid, u8 instance, u32 method_id,
const struct acpi_buffer *in, struct acpi_buffer *out)

wmi_query_block(const char *guid, u8 instance,
struct acpi_buffer *out)

wmi_set_block(const char *guid, u38 instance,
const struct acpi_buffer *in)

wmi_install_notify_handler(acpi_notify_handler handler);

wmi_remove_notify_handler(void);

wmi_get_event_data(u32 event, struct acpi_buffer *out)

wmi_has_guid(const char guid*)

wmi_has_guid() is a helper function to find if a GUID exists or not on the
system (a quick and easy way for WMI dependant drivers to see if the
the method/ block they want exists, since GUIDs are supposed to be unique).

Event handling - allow a WMI based driver to register a notifier handler
for each GUID with WMI. When a notification is sent to a GUID in WMI, the
handler registered with WMI is then called (it is left to the caller to
ask for the WMI event data associated with the GUID, if needed).

What it won't do:

Unicode - The MS article[1] calls for converting between ASCII and Unicode (or
vice versa) if a GUID is marked as "string". This is left up to the calling
driver.

Handle a MOF[1] - the WMI mapper just exports methods, data and events to
userspace. MOF handling is down to userspace.

Userspace interface - this will be added later.

[1] http://www.microsoft.com/whdc/system/pnppwr/wmi/wmi-acpi.mspx

===
ChangeLog
==

v1 (2007-10-02):

* Initial release

v2 (2007-10-05):

* Cleaned up code - split up super "wmi_evaluate_block" -> each external
  symbol now handles its own ACPI calls, rather than handing off to
  a "super" method (and in turn, is a lot simpler to read)
* Added a find_guid() symbol - return true if a given GUID exists on
  the system
* wmi_* functions now return type acpi_status (since they are just
  fancy wrappers around acpi_evaluate_object())
* Removed extra debug code

v3 (2007-10-27)

* More code clean up - now passes checkpatch.pl
* Change data block calls - ref MS spec, method ID is not required for
  them, so drop it from the function parameters.
* Const'ify guid in the function call parameters.
* Fix _WDG buffer handling - copy the data to our own private structure.
* Change WMI from tristate to bool - otherwise the external functions are
  not exported in linux/acpi.h if you try to build WMI as a module.
* Fix more flag comparisons.
* Add a maintainers entry - since I wrote this, I should take the blame
  for it.

v4 (2007-10-30)

* Add missing brace from after fixing checkpatch errors.
* Rewrote event handling - allow external drivers to register with WMI to
  handle WMI events
* Clean up flags and sanitise flag handling

v5 (2007-11-03)

* Add sysfs interface for userspace. Export events over netlink again.
* Remove module left overs, fully convert to built-in driver.
* Tweak in-kernel API to use u8 for instance, since this is what the GUID
  blocks use (so instance cannot be greater than u8).
* Export wmi_get_event_data() for in kernel WMI drivers.

v6 (2007-11-07)

* Split out userspace into a different patch

v7 (2007-11-20)

* Fix driver to handle multiple PNP0C14 devices - store all GUIDs using
  the kernel's built in list functions, and just keep adding to the list
  every time we handle a PNP0C14 devices - GUIDs will always be unique,
  and WMI callers do not know or care about different devices.
* Change WMI event handler registration to use its' own event handling
  struct; we should not pass an acpi_handle down to any WMI based drivers
  - they should be able to function with only the calls provided in WMI.
* Update my e-mail address

v8 (2007-11-28)

* Convert back to a module.
* Update Kconfig to default to building as a module.
* Remove an erroneous printk.
* Simply comments for string flag (since we now leave the handling to the
  caller).

v9 (2007-12-07)

* Add back missing MODULE_DEVICE_TABLE for autoloading
* Checkpatch fixes

v10 (2007-12-12)

* Workaround broken GUIDs declared expensive without a WCxx method.
* Minor cleanups

v11 (2007-12-17)

* More fixing for broken GUIDs declared expensive without a WCxx method.
* Add basic EmbeddedControl region handling.

v12 (2007-12-18)

* Changed EC region handling code, as per Alexey's comments.

v13 (2007-12-27)

* Changed event handling so that we can have one event handler registered
  per GUID, as per Matthew Garrett's suggestion.

v14 (2008-01-12)

* Remove ACPI debug statements

v15 (2008-02-01)

* Replace two remaining 'x == NULL' type tests with '!x'

v16 (2008-02-05)

* Change MAINTAINERS entry, as I am not, and never have been, paid to work
  on WMI
* Remove 'default' line from Kconfig
Signed-off-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
CC: Matthew Garrett <mjg59@srcf.ucam.org>
CC: Alexey Starikovskiy <aystarik@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>