The new-style thmc50 driver implements the optional detect()
callback to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
The new-style smsc47m192 driver implements the optional detect()
callback to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hartmut Rick <linux@rick.claranet.de>
The new-style max6650 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hans J. Koch <hjk@linutronix.de>
The new-style max1619 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Alexey Fisher <fishor@mail.ru>
The new-style lm93 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Cc: Eric J. Bowersox <ericb@aspsys.com>
Cc: Carsten Emde <cbe@osadl.org>
Cc: Hans J. Koch <hjk@linutronix.de>
The new-style lm92 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style lm90 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style lm87 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ben Hutchings <bhutchings@solarflare.com>
The new-style lm83 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style lm80 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style lm77 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Andras Bali <drewie@freemail.hu>
The new-style lm63 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style gl520sm driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Maarten Deprez <maartendeprez@users.sourceforge.net>
The new-style gl518sm driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style fscpos driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style fschmd driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hans de Goede <j.w.r.degoede@hhs.nl>
The new-style fscher driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Reinhard Nissl <rnissl@gmx.de>
Drop the legacy f75375s i2c driver, and add a detect callback to the
new-style i2c driver to achieve the same functionality.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Riku Voipio <riku.voipio@movial.fi>
The new-style ds1621 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style atxp1 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style asb100 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style adt7473 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Darrick J. Wong <djwong@us.ibm.com>
The new-style adt7470 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Darrick J. Wong <djwong@us.ibm.com>
The new-style ads7828 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style adm9240 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Grant Coady <gcoady.lk@gmail.com>
The new-style adm1031 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Alexandre d'Alton <alex@alexdalton.org>
The new-style adm1029 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Corentin Labbe <corentin.labbe@geomatys.fr>
The new-style adm1026 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style adm1025 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style adm1021 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The ad7418 driver is only used on embedded platforms where i2c
devices can easily be declared in platform code. Thus a new-style
i2c driver makes perfect sense. This lets us get rid of quirky
detection code (these chips have no identification registers) and
shrinks the binary driver size by 38%.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
The new-style ds2482 driver implements the optional detect() callback
to cover the use cases of the legacy driver. I'm curious if anyone
really needs this though, so it might be removed in the feature.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style max6875 driver implements the optional detect() callback
to cover the use cases of the legacy driver. I'm curious if anyone
really needs this though, so it might be removed in the feature.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style pca9539 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Warning: users will now have to use the force module parameter to get
the driver to attach to their device. That's not a bad thing as these
devices can't be detected anyway.
Note that this doesn't change the fact that this driver is deprecated
in favor of gpio/pca953x.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style pcf8575 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Warning: users will now have to use the force module parameter to get
the driver to attach to their device. That's not a bad thing as these
devices can't be detected anyway.
Note that this doesn't change the fact that this driver is deprecated
in favor of gpio/pcf857x.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style pcf8574 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Warning: users will now have to use the force module parameter to get
the driver to attach to their device. That's not a bad thing as these
devices can't be detected anyway.
Note that this doesn't change the fact that this driver is deprecated
in favor of gpio/pcf857x.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style pcf8591 driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The new-style eeprom driver implements the optional detect() callback
to cover the use cases of the legacy driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Clear i2c_adapter.dev on adapter removal. This makes it possible to
re-add the adapter at a later point, which some drivers
(i2c-amd756-s4882, i2c-nforce2-s4985) actually do.
This fixes a bug reported by John Stultz here:
http://lkml.org/lkml/2008/7/15/720
and by Ingo Molar there:
http://lkml.org/lkml/2008/7/16/78
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Fix bug in kernel_physical_mapping_init() that causes kernel
page table to be built incorrectly for systems with greater
than 512GB of memory.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Proper memory barriers have been added to order accesses
to ->cmd_busy, so volatile declaration for cmd_busy can
be removed.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Provide a .gitignore file, and fix a typo which prevented some of the
generated binary files from being removed on 'make clean'.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Reported-and-tested-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
the paravirt-spinlock patches caused a boot hang with this config:
http://redhat.com/~mingo/misc/config-Wed_Jul__9_14_47_04_CEST_2008.bad
i have bisected it down to:
| commit e17b58c2e85bc2ad2afc07fb8d898017c2b75ed1
| Author: Jeremy Fitzhardinge <jeremy@goop.org>
| Date: Mon Jul 7 12:07:53 2008 -0700
|
| xen: implement Xen-specific spinlocks
i.e. applying that patch alone causes the hang. The hang happens in the
ftrace self-test:
initcall utsname_sysctl_init+0x0/0x19 returned 0 after 0 msecs
calling init_sched_switch_trace+0x0/0x4c
Testing tracer sched_switch: PASSED
initcall init_sched_switch_trace+0x0/0x4c returned 0 after 167 msecs
calling init_function_trace+0x0/0x12
Testing tracer ftrace:
[hard hang]
it should have continued like this:
Testing tracer ftrace: PASSED
initcall init_function_trace+0x0/0x12 returned 0 after 198 msecs
calling init_irqsoff_tracer+0x0/0x14
Testing tracer irqsoff: PASSED
initcall init_irqsoff_tracer+0x0/0x14 returned 0 after 3 msecs
calling init_mmio_trace+0x0/0x12
initcall init_mmio_trace+0x0/0x12 returned 0 after 0 msecs
the problem is that such lowlevel primitives as spinlocks should never
be built with -pg (which ftrace does). Marking paravirt.o as non-pg and
marking all spinlock ops as always-inline solve the hang.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The standard ticket spinlocks are very expensive in a virtual
environment, because their performance depends on Xen's scheduler
giving vcpus time in the order that they're supposed to take the
spinlock.
This implements a Xen-specific spinlock, which should be much more
efficient.
The fast-path is essentially the old Linux-x86 locks, using a single
lock byte. The locker decrements the byte; if the result is 0, then
they have the lock. If the lock is negative, then locker must spin
until the lock is positive again.
When there's contention, the locker spin for 2^16[*] iterations waiting
to get the lock. If it fails to get the lock in that time, it adds
itself to the contention count in the lock and blocks on a per-cpu
event channel.
When unlocking the spinlock, the locker looks to see if there's anyone
blocked waiting for the lock by checking for a non-zero waiter count.
If there's a waiter, it traverses the per-cpu "lock_spinners"
variable, which contains which lock each CPU is waiting on. It picks
one CPU waiting on the lock and sends it an event to wake it up.
This allows efficient fast-path spinlock operation, while allowing
spinning vcpus to give up their processor time while waiting for a
contended lock.
[*] 2^16 iterations is threshold at which 98% locks have been taken
according to Thomas Friebel's Xen Summit talk "Preventing Guests from
Spinning Around". Therefore, we'd expect the lock and unlock slow
paths will only be entered 2% of the time.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <clameter@linux-foundation.org>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Virtualization <virtualization@lists.linux-foundation.org>
Cc: Xen devel <xen-devel@lists.xensource.com>
Cc: Thomas Friebel <thomas.friebel@amd.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Switch to using the lock-byte spinlock implementation, to avoid the
worst of the performance hit from ticket locks.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <clameter@linux-foundation.org>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Virtualization <virtualization@lists.linux-foundation.org>
Cc: Xen devel <xen-devel@lists.xensource.com>
Cc: Thomas Friebel <thomas.friebel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Implement a version of the old spinlock algorithm, in which everyone
spins waiting for a lock byte. In order to be compatible with the
ticket-lock's use of a zero initializer, this uses the convention of
'0' for unlocked and '1' for locked.
This algorithm is much better than ticket locks in a virtual
envionment, because it doesn't interact badly with the vcpu scheduler.
If there are multiple vcpus spinning on a lock and the lock is
released, the next vcpu to be scheduled will take the lock, rather
than cycling around until the next ticketed vcpu gets it.
To use this, you must call paravirt_use_bytelocks() very early, before
any spinlocks have been taken.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <clameter@linux-foundation.org>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Virtualization <virtualization@lists.linux-foundation.org>
Cc: Xen devel <xen-devel@lists.xensource.com>
Cc: Thomas Friebel <thomas.friebel@amd.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ticket spinlocks have absolutely ghastly worst-case performance
characteristics in a virtual environment. If there is any contention
for physical CPUs (ie, there are more runnable vcpus than cpus), then
ticket locks can cause the system to end up spending 90+% of its time
spinning.
The problem is that (v)cpus waiting on a ticket spinlock will be
granted access to the lock in strict order they got their tickets. If
the hypervisor scheduler doesn't give the vcpus time in that order,
they will burn timeslices waiting for the scheduler to give the right
vcpu some time. In the worst case it could take O(n^2) vcpu scheduler
timeslices for everyone waiting on the lock to get it, not counting
new cpus trying to take the lock while the log-jam is sorted out.
These hooks allow a paravirt backend to replace the spinlock
implementation.
At the very least, this could revert the implementation back to the
old lock algorithm, which allows the next scheduled vcpu to take the
lock, and has basically fairly good performance.
It also allows the spinlocks to take advantages of the hypervisor
features to make locks more efficient (spin and block, for example).
The cost to native execution is an extra direct call when using a
spinlock function. There's no overhead if CONFIG_PARAVIRT is turned
off.
The lock structure is fixed at a single "unsigned int", initialized to
zero, but the spinlock implementation can use it as it wishes.
Thanks to Thomas Friebel's Xen Summit talk "Preventing Guests from
Spinning Around" for pointing out this problem.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <clameter@linux-foundation.org>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Virtualization <virtualization@lists.linux-foundation.org>
Cc: Xen devel <xen-devel@lists.xensource.com>
Cc: Thomas Friebel <thomas.friebel@amd.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
