This is a new generic kernel FIFO implementation.
The current kernel fifo API is not very widely used, because it has to
many constrains. Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.
I think this are the reasons why kfifo is not in use:
- The API is to simple, important functions are missing
- A fifo can be only allocated dynamically
- There is a requirement of a spinlock whether you need it or not
- There is no support for data records inside a fifo
So I decided to extend the kfifo in a more generic way without blowing up
the API to much. The new API has the following benefits:
- Generic usage: For kernel internal use and/or device driver.
- Provide an API for the most use case.
- Slim API: The whole API provides 25 functions.
- Linux style habit.
- DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
- Direct copy_to_user from the fifo and copy_from_user into the fifo.
- The kfifo itself is an in place member of the using data structure, this save an
indirection access and does not waste the kernel allocator.
- Lockless access: if only one reader and one writer is active on the fifo,
which is the common use case, no additional locking is necessary.
- Remove spinlock - give the user the freedom of choice what kind of locking to use if
one is required.
- Ability to handle records. Three type of records are supported:
- Variable length records between 0-255 bytes, with a record size
field of 1 bytes.
- Variable length records between 0-65535 bytes, with a record size
field of 2 bytes.
- Fixed size records, which no record size field.
- Preserve memory resource.
- Performance!
- Easy to use!
This patch:
Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure. This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them. This
patch changes the implementation and all existing users.
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A follow-up 2.6.32-rc1's
1e384cb0f9
"fujitsu-laptop: support led-class as module"
It's a trivial fix for one of the CONFIG_LEDS_CLASS ifdefs
which was somehow missed in the original patch.
Signed-off-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len 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: Len Brown <len.brown@intel.com>
Increment driver version to reflect the changes from this patch series.
Signed-off-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>
* Move led_classdev_unregister() calls from fujitsu_cleanup() to
acpi_fujitsu_hotkey_remove().
* Fix ordering in fujitsu_cleanup().
* Fix backlight_device_register() failure handling in fujitsu_init().
* Add missing sysfs group removal on failure to fujitsu_init().
* Add input device unregistering on failure to acpi_fujitsu_add()
and acpi_fujitsu_hotkey_add().
* Add input device unregistering/freeing to acpi_fujitsu_remove()
and acpi_fujitsu_hotkey_remove() (also remove superfluous 'device'
and 'acpi_driver_data(device)' checks while at it).
* Do few minor cleanups.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>
This takes care of the following entries from Dan's list:
drivers/platform/x86/fujitsu-laptop.c +327 set_lcd_level(13) warning:
variable derefenced before check 'fujitsu'
drivers/platform/x86/fujitsu-laptop.c +358 set_lcd_level_alt(13) warning:
variable derefenced before check 'fujitsu'
Reported-by: Dan Carpenter <error27@gmail.com>
Cc: corbet@lwn.net
Cc: eteo@redhat.com
Cc: Julia Lawall <julia@diku.dk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>
device and acpi_driver_data(device) were tested just a few lines above.
A simplified version of the semantic match that finds this problem is as
follows: (http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r exists@
local idexpression x;
expression E;
@@
if (x == NULL || ...) { ... when forall
return ...; }
.. when != \(x=E\|x--\|x++\|--x\|++x\|x-=E\|x+=E\|x|=E\|x&=E\|&x\)
(
*x == NULL
|
*x != NULL
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>
Support fujitsu-laptop with led-class built as a module instead of
being compiled in.
Signed-off-by: Stephen Gildea <stepheng+linux@gildea.com>
Acked-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>
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.
Tested by Tony on Fujitsu-Siemens Lifebook S6420 [FJNB1E6] with
BIOS 1.18 (01/09/2009). Tested by Jonathan on Fujitsu S7020.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Tony Vroon <tony@linx.net>
Tested-By: Tony Vroon <tony@linx.net>
Acked-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Tested-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>
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.
Tested by Tony on Fujitsu-Siemens Lifebook S6420 [FJNB1E6] with
BIOS 1.18 (01/09/2009). Tested by Jonathan on Fujitsu S7020.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Tony Vroon <tony@linx.net>
Tested-By: Tony Vroon <tony@linx.net>
Acked-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Tested-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>
Up until now, we polled the rfkill status for every incoming FUJ02E3 ACPI event.
It turns out that the firmware has a bitmask which indicates what rfkill-related
state it can report.
The rfkill_supported bitmask is now used to avoid polling for rfkill at all in
the notification handler if there is no support. Also, it is used in the platform
device callbacks. As before we register all callbacks and report "unknown" if the
firmware does not give us status updates for that particular bit.
This was fed through checkpatch.pl and tested on the S6420, S7020 and P8010
platforms.
Signed-off-by: Tony Vroon <tony@linx.net>
Tested-by: Stephen Gildea <stepheng+linux@gildea.com>
Acked-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>
Move x86 platform specific drivers from drivers/misc/
to a new home under drivers/platform/x86/.
The community has been maintaining x86 vendor-specific
platform specific drivers under /drivers/misc/ for a few years.
The oldest ones started life under drivers/acpi.
They moved out of drivers/acpi/ because they don't actually
implement the ACPI specification, but either simply
use ACPI, or implement vendor-specific ACPI extensions.
In the future we anticipate...
drivers/misc/ will go away.
other architectures will create drivers/platform/<arch>
Signed-off-by: Len Brown <len.brown@intel.com>
Stefani Seibold
Jonathan Woithe
Len Brown
Bartlomiej Zolnierkiewicz
Julia Lawall
Stephen Gildea
Bjorn Helgaas
Tony Vroon