This facility provides three entry points:
ilog2() Log base 2 of unsigned long
ilog2_u32() Log base 2 of u32
ilog2_u64() Log base 2 of u64
These facilities can either be used inside functions on dynamic data:
int do_something(long q)
{
...;
y = ilog2(x)
...;
}
Or can be used to statically initialise global variables with constant values:
unsigned n = ilog2(27);
When performing static initialisation, the compiler will report "error:
initializer element is not constant" if asked to take a log of zero or of
something not reducible to a constant. They treat negative numbers as
unsigned.
When not dealing with a constant, they fall back to using fls() which permits
them to use arch-specific log calculation instructions - such as BSR on
x86/x86_64 or SCAN on FRV - if available.
[akpm@osdl.org: MMC fix]
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Wojtek Kaniewski <wojtekka@toxygen.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
md_open takes ->reconfig_mutex which causes lockdep to complain. This
(normally) doesn't have deadlock potential as the possible conflict is with a
reconfig_mutex in a different device.
I say "normally" because if a loop were created in the array->member hierarchy
a deadlock could happen. However that causes bigger problems than a deadlock
and should be fixed independently.
So we flag the lock in md_open as a nested lock. This requires defining
mutex_lock_interruptible_nested.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a sysfs and debugfs interface to the pktcdvd driver.
Look into the Documentation/ABI/testing/* files in the patch for more info.
Signed-off-by: Thomas Maier <balagi@justmail.de>
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds a bio write queue congestion control to the pktcdvd driver with
fixed on/off marks. It prevents that the driver consumes a unlimited
amount of write requests.
[akpm@osdl.org: sync with congestion_wait() renaming]
Signed-off-by: Thomas Maier <balagi@justmail.de>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes some of the procfs functions reusable (for
coming sysfs patch e.g.):
pkt_setup_dev()
pkt_remove_dev()
...
Signed-off-by: Thomas Maier <balagi@justmail.de>
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix the locking of signal->tty.
Use ->sighand->siglock to protect ->signal->tty; this lock is already used
by most other members of ->signal/->sighand. And unless we are 'current'
or the tasklist_lock is held we need ->siglock to access ->signal anyway.
(NOTE: sys_unshare() is broken wrt ->sighand locking rules)
Note that tty_mutex is held over tty destruction, so while holding
tty_mutex any tty pointer remains valid. Otherwise the lifetime of ttys
are governed by their open file handles. This leaves some holes for tty
access from signal->tty (or any other non file related tty access).
It solves the tty SLAB scribbles we were seeing.
(NOTE: the change from group_send_sig_info to __group_send_sig_info needs to
be examined by someone familiar with the security framework, I think
it is safe given the SEND_SIG_PRIV from other __group_send_sig_info
invocations)
[schwidefsky@de.ibm.com: 3270 fix]
[akpm@osdl.org: various post-viro fixes]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- create a 'pseudo_subchannel' per channel subsystem (the 'orphanage')
- use the orphanage as a shelter for ccw_devices that can't remain on the same
subchannel
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove CONFIG_QETH_PERF_STATS and use a sysfs attribute instead.
We want to have the ability to turn the statistics on/off at runtime.
Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
It is now possible to enable/disable ERP related logging without re-compile
and re-ipl. A additional sysfs-attribute 'erplog' allows to switch the
logging non-interruptive.
Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
inlined below is the patch that adds physmap driver for of_device.
It's an MTD part of the two-part support for flash/ROM devices based
on Open Firmware descriptions. The arch part (currently only PowerPC
which is no surprise) was introduced to powerpc folks earlier and
recently the older version of the powerpc part has been included into
the powerpc.git tree
(see http://www.kernel.org/git/?p=linux/kernel/git/paulus/powerpc.git;a=commitdiff;h=28f9ec349ae47c91768b7bc5607db4442c818e11).
drivers/mtd/maps/Kconfig | 9 +
drivers/mtd/maps/Makefile | 1
drivers/mtd/maps/physmap_of.c | 255 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 265 insertions(+)
Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: Sergey Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
RedBoot supports storing the FIS directory and the RedBoot
configuration area in the same block of flash memory. This is
not the most common RedBoot configuration, but it is used on
commercially available boards supported by the kernel.
A recent patch to mtd/redboot.c (http://lkml.org/lkml/2006/3/20/410)
which corrected the skipping of deleted table entries has exposed the
latent problem of the kernel redboot parser running off the end of the
FIS directory and interpreting the RedBoot configuration information
as table entries.
This patch terminates the table parsing when the first truly empty
entry is found (table entry deletion only clears the first byte of the
name, so two cleared bytes in a row indicates the end of the table),
thereby supporting the combined redboot FIS directory and RedBoot
configuration information flash layout scenario.
Signed-off-by: Rod Whitby <rod@whitby.id.au>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Add support for 16-bit NAND bus-width for the AT91 NAND driver.
The 16-bit NAND is found on the Atmel AT91SAM9260-EK and AT91SAM9261-EK
boards.
Orignal Patch from Patrice Vilchez
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
