Sebastien Dugue [Mon, 1 Dec 2008 13:09:07 +0000 (14:09 +0100)]
hrtimers: allow the hot-unplugging of all cpus
Impact: fix CPU hotplug hang on Power6 testbox
On architectures that support offlining all cpus (at least powerpc/pseries),
hot-unpluging the tick_do_timer_cpu can result in a system hang.
This comes from the fact that if the cpu going down happens to be the
cpu doing the tick, then as the tick_do_timer_cpu handover happens after the
cpu is dead (via the CPU_DEAD notification), we're left without ticks,
jiffies are frozen and any task relying on timers (msleep, ...) is stuck.
That's particularly the case for the cpu looping in __cpu_die() waiting
for the dying cpu to be dead.
This patch addresses this by having the tick_do_timer_cpu handover happen
earlier during the CPU_DYING notification. For this, a new clockevent
notification type is introduced (CLOCK_EVT_NOTIFY_CPU_DYING) which is triggered
in hrtimer_cpu_notify().
hrtimers: increase clock min delta threshold while interrupt hanging
Impact: avoid timer IRQ hanging slow systems
While using the function graph tracer on a virtualized system, the
hrtimer_interrupt can hang the system on an infinite loop.
This can be caused in several situations:
- the hardware is very slow and HZ is set too high
- something intrusive is slowing the system down (tracing under emulation)
... and the next clock events to program are always before the current time.
This patch implements a reasonable compromise: if such a situation is
detected, we share the CPUs time in 1/4 to process the hrtimer interrupts.
This is enough to let the system running without serious starvation.
It has been successfully tested under VirtualBox with 1000 HZ and 100 HZ
with function graph tracer launched. On both cases, the clock events were
increased until about 25 ms periodic ticks, which means 40 HZ.
So we change a hard to debug hang into a warning message and a system that
still manages to limp along.
Phil Sutter [Thu, 22 Jan 2009 18:32:43 +0000 (19:32 +0100)]
MIPS: RB532: Export rb532_gpio_set_func()
This kernel symbol provides a way for drivers to switch on alternate
function for a certain GPIO pin. Turning it off is done implicitly when
changing the GPIO direction, as that would be fixed when using the given
pin als alternate function.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Phil Sutter [Mon, 19 Jan 2009 22:42:54 +0000 (23:42 +0100)]
MIPS: RB532: Simplify dev3 init
As rb532_dev3_ctl_res is not used by any platform device, it can be dropped
when not used for holding the physical address of the device 3 controller.
Also a size of one byte should suffice when ioremapping the physical
address mentioned above, as only a single byte is being read from and
written to it.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Phil Sutter [Mon, 19 Jan 2009 22:42:52 +0000 (23:42 +0100)]
MIPS: RB532: Move dev3 init code to devices.c
This code doesn't belong to gpio.c, as it's completely unrelated to
GPIO. As dev1 and dev2 init code is in devices.c, it seems to be a more
adequate place.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Phil Sutter [Mon, 19 Jan 2009 22:42:51 +0000 (23:42 +0100)]
MIPS: RB532: Fix set_latch_u5()
The data to be written is just a byte, so use writeb instead of writel.
Also, dev3.base contains the address, not the data so referencing here
is wrong.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Phil Sutter [Thu, 15 Jan 2009 14:41:44 +0000 (15:41 +0100)]
MIPS: RB532: Use driver_data instead of platform_data
As the korina ethernet driver uses platform_get_drvdata() to extract the
driver specific data from the platform device, driver_data has to be
used here.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Auto-detection works just fine, so use it instead of specifying the type
manually. Also define a platform device for the uart, as suggested by
David Daney.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
As the pata-rb532-cf driver calls gpio_direction_input(), the calls to
rb532_gpio_set_func() and rb532_gpio_direction_input() are not needed since
the alternate function is automatically being disabled when changing the
GPIO pin direction.
The later two calls to rb532_gpio_set_{ilevel,istat}() are implicitly being
done by the IRQ initialisation of pata-rb532-cf.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Phil Sutter [Fri, 28 Nov 2008 19:46:09 +0000 (20:46 +0100)]
MIPS: RB532: Auto disable GPIO alternate function
When a driver calls gpio_set_direction_{input,output}(), it obviously
doesn't want the alternate function for that pin to be active (as the
direction would not matter in that case). This patch ensures alternate
function is disabled when the direction is being changed.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Phil Sutter [Fri, 28 Nov 2008 19:45:10 +0000 (20:45 +0100)]
MIPS: RB532: Add set_type() function to IRQ struct.
Interrupt Group 4 mapps the GPIO pins enabled as interrupt sources;
add defines to make this clear when addressing them later in code.
The mapped GPIOs support triggering on either level high or low. To
achieve this, the set_type() function calls rb532_gpio_set_ilevel() for
interrupts of the above mentioned group.
As there is no way to alter the triggering characteristics of the other
interrupts, accept level triggering on status high only. (This is just a
guess; but as the system boots fine and interrupt-driven devices (e.g.
serial console) work with no implications, it seems to be right.)
To clear a GPIO mapped IRQ, the source has to be cleared (i.e., the
interrupt status bit of the corresponding GPIO pin). This is done inside
rb532_disable_irq().
After applying these changes I could undo most of my former "fixes" to
pata-rb532-cf. Particularly all interrupt handling can be done
generically via set_irq_type() as it was before.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Phil Sutter [Tue, 11 Nov 2008 23:09:30 +0000 (00:09 +0100)]
MIPS: RB532: Fix bit swapping in rb532_set_bit()
The algorithm works unconditionally. If bitval is one, the first line is
a no op and the second line sets the bit at offset position. Vice versa,
if bitval is zero, the first line clears the bit at offset position and
the second line is a no op.
Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
David Daney [Mon, 5 Jan 2009 23:29:58 +0000 (15:29 -0800)]
MIPS: Read watch registers with interrupts disabled.
If a context switch occurred between the watch exception and reading the
watch registers, it would be possible for the new process to corrupt their
state. Enabling interrupts only after the watch registers are read avoids
this race.
Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Ralf Baechle [Wed, 28 Jan 2009 17:48:40 +0000 (17:48 +0000)]
MIPS: IP27: Switch from DMA_IP27 to DMA_COHERENT
The special IP27 DMA code selected by DMA_IP27 has been removed a while
ago turning DMA_IP27 into almost a nop. Also fixup the broken logic of
its last users memcpy.S and memcpy-inatomic.s.
Ralf Baechle [Mon, 12 Jan 2009 00:52:18 +0000 (00:52 +0000)]
MIPS: atomic_*(): Change type of intermediate variables.
This shaves of 1912 bytes of an IP27 defconfig kernel and avoids
unexpected overflow behaviour in atomic_sub_if_positive. Apply the same
changes to the atomic64_* functions for consistency.
Linus Torvalds [Fri, 30 Jan 2009 19:37:22 +0000 (11:37 -0800)]
Allow opportunistic merging of VM_CAN_NONLINEAR areas
Commit de33c8db5910cda599899dd431cc30d7c1018cbf ("Fix OOPS in
mmap_region() when merging adjacent VM_LOCKED file segments") unified
the vma merging of anonymous and file maps to just one place, which
simplified the code and fixed a use-after-free bug that could cause an
oops.
But by doing the merge opportunistically before even having called
->mmap() on the file method, it now compares two different 'vm_flags'
values: the pre-mmap() value of the new not-yet-formed vma, and previous
mappings of the same file around it.
And in doing so, it refused to merge the common file case, which adds a
marker to say "I can be made non-linear".
This fixes it by just adding a set of flags that don't have to match,
because we know they are ok to merge. Currently it's only that single
VM_CAN_NONLINEAR flag, but at least conceptually there could be others
in the future.
Reported-and-acked-by: Hugh Dickins <hugh@veritas.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
usr/include/asm/swab.h:4: include of <linux/types.h> is preferred over <asm/types.h>
usr/include/asm/swab.h:7: found __[us]{8,16,32,64} type without #include <linux/types.h>
usr/include/asm/sigcontext.h:5: include of <linux/types.h> is preferred over <asm/types.h>
usr/include/asm/sigcontext.h:24: found __[us]{8,16,32,64} type without #include <linux/types.h>
usr/include/asm/ptrace-abi.h:86: include of <linux/types.h> is preferred over <asm/types.h>
usr/include/asm/ptrace-abi.h:93: found __[us]{8,16,32,64} type without #include <linux/types.h>
usr/include/asm/mce.h:7: include of <linux/types.h> is preferred over <asm/types.h>
usr/include/asm/mce.h:29: found __[us]{8,16,32,64} type without #include <linux/types.h>
usr/include/asm/kvm.h:9: include of <linux/types.h> is preferred over <asm/types.h>
usr/include/asm/kvm.h:16: found __[us]{8,16,32,64} type without #include <linux/types.h>
usr/include/video/sisfb.h:25: include of <linux/types.h> is preferred over <asm/types.h>
usr/include/video/sisfb.h:78: found __[us]{8,16,32,64} type without #include <linux/types.h>
usr/include/linux/sound.h:33: extern's make no sense in userspace
usr/include/linux/sound.h:34: extern's make no sense in userspace
usr/include/linux/sound.h:35: extern's make no sense in userspace
usr/include/linux/sound.h:36: extern's make no sense in userspace
usr/include/linux/sound.h:37: extern's make no sense in userspace
usr/include/linux/sound.h:39: extern's make no sense in userspace
usr/include/linux/sound.h:40: extern's make no sense in userspace
usr/include/linux/sound.h:41: extern's make no sense in userspace
usr/include/linux/sound.h:42: extern's make no sense in userspace
usr/include/linux/elf.h:379: extern's make no sense in userspace
usr/include/linux/elf.h:387: extern's make no sense in userspace
usr/include/linux/elf.h:401: extern's make no sense in userspace
usr/include/linux/elf.h:402: extern's make no sense in userspace
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