The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.
For the various event classes:
- hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
the PMI-tail (ARM etc.)
- tracepoint: nmi=0; since tracepoint could be from NMI context.
- software: nmi=[0,1]; some, like the schedule thing cannot
perform wakeups, and hence need 0.
As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).
The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On some arches (x86, sh, arm, unicore, powerpc) the oops message would
print out the last sysfs file accessed.
This was very useful in finding a number of sysfs and driver core bugs
in the 2.5 and early 2.6 development days, but it has been a number of
years since this file has actually helped in debugging anything that
couldn't also be trivially determined from the stack traceback.
So it's time to delete the line. This is good as we need all the space
we can get for oops messages at times on consoles.
Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Update the SH kernel to keep SR.BL set until the VBR
register has been initialized. Useful to allow boot
of the kernel even though exceptions are pending.
Without this patch there is a window of time when
exceptions such as NMI are enabled but no exception
handlers are installed.
This patch modifies both the zImage loader and the
actual kernel to boot with BL=1, but the zImage
loader is modfied in such a way that the init_sr
value is unchanged to not break the zImage loader
provided by kexec.
Tested on sh7724 Ecovec and on the SH4AL-DSP core
included in sh7372.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
vmemmap and the vmsplit code amongst others need to be able to take page
faults much earlier than trap_init() time, so move this in to the early
CPU initialization. VBR setup for secondary CPUs is already handled
through start_secondary(), so we only need to do this for the boot CPU.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This splits out the unaligned access counters and userspace bits in to
their own generic interface, which will allow them to be wired up on sh64
too.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This moves the VBR handling out of the main trap handling code and in to
the sh-bios helper code. A couple of accessors are added in order to
permit other kernel code to get at the VBR value for state save/restore
paths.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Presently there are a couple of paths in to the alignment handler, where
only the address error path presently quiets the notificiation messages
based on the configuration settings. We carry over the notification level
tests to the default alignment handler itself incase so that they behave
uniformly.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
SCIF2 and the FPU exceptions happen to share vector numbers, one in
EXPEVT and the other in INTEVT. This is a violation of the interface and
should have never made it in to silicon. On top of that, the demux hack
that was added for special dispatch is rather error prone, and introduces
more problems than it solves. Kill all of it off, and just refuse to deal
with SCIF2 outright.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This follows the ARM change, as SH had all of the same issues:
Make die() better match x86:
- add printing of the last accessed sysfs file
- ensure console_verbose() is called under the lock
- ensure we panic outside of oops_exit()
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Certain networking and USB workloads generate floods of these accesses,
so just disable it by default (thereby restoring the old behaviour). The
option remains configurable from userspace, and can still be used as a
debugging aid.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
In the unaligned kernel exception fixup case the printk() was ordered
before the copy_from_user(), resulting in a nonsensical instruction
value. This fixes up the ordering properly.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This adds some sanity checking in the unaligned instruction handler to
verify the instruction size, which enables basic support for 16-bit
fixups on SH-2A parts.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Some unaligned accesses are completely expected. For example, the
trapped_io code uses the unaligned access fixup code path so there's no
need to warn about having to fixup the unaligned access.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch fixes a few problems with the existing code in do_address_error().
a) the variable used to printk()d the offending instruction wasn't
initialized correctly. This is a fix to bug 5727
b) behaviour for CONFIG_CPU_SH2A wasn't correct
c) the 'ignore address error' behaviour didn't update the PC, causing an
infinite loop.
Signed-off-by: Andre Draszik <andre.draszik@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch brings the SH4 misaligned trap handler in line with what
happens on ARM:
Add a /proc/cpu/alignment which can be read from to get alignment
trap statistics and written to to influence the behaviour of the
alignment trap handling. The value to write is a bitfield, which
has the following meaning: 1 warn, 2 fixup, 4 signal
In addition, we add a /proc/cpu/kernel_alignment, to enable or
disable warnings in case of kernel code causing alignment errors.
Signed-off by: Andre Draszik <andre.draszik@st.com>
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch makes sure we see messages about unaligned access fixups
every now and then. Else especially userspace apps suffering from
bad programming won't ever be noticed...
Signed-off by: Andre Draszik <andre.draszik@st.com>
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
We can't assume that if we execute the unwinder code and the unwinder
was already running that it has faulted. Clearly two kernel threads can
invoke the unwinder at the same time and may be running simultaneously.
The previous approach used BUG() and BUG_ON() in the unwinder code to
detect whether the unwinder was incapable of unwinding the stack, and
that the next available unwinder should be used instead. A better
approach is to explicitly invoke a trap handler to switch unwinders when
the current unwinder cannot continue.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Copy the stacktrace ops code from x86 and provide a central function for
use by functions that need to dump a callstack.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
There were a number of issues with the DSP context save/restore code,
mostly left-over relics from when it was introduced on SH3-DSP with
little follow-up testing, resulting in things like task_pt_dspregs()
referencing incorrect state on the stack.
This follows the MIPS convention of tracking the DSP state in the
thread_struct and handling the state save/restore in switch_to() and
finish_arch_switch() respectively. The regset interface is also updated,
which allows us to finally be rid of task_pt_dspregs() and the special
cased task_pt_regs().
Signed-off-by: Michael Trimarchi <michael@evidence.eu.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
unaligned and nonexistent address causes wrong exception
handling in traps_32.c(handle_unaligned_access).
'handle_unalinged_ins' should return -EFAULT if address error
is fixed up with kernel exception table, otherwise
'handle_unaligned_access' increases already fixed program counter
and then crash.
for example
ioctl(fd, TCGETA, (struct termio *)-1)
never return and stay in TASK_UNINTERRUPTIBLE state forever
in my kernel.
Signed-off-by: SUGIOKA Toshinobu <sugioka@itonet.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
While looking at reducing the amount of architecture namespace pollution
in the generic kernel, I found that asm/irq.h is included in the vast
majority of compilations on ARM (around 650 files.)
Since asm/irq.h includes a sub-architecture include file on ARM, this
causes a negative impact on the ccache's ability to re-use the build
results from other sub-architectures, so we have a desire to reduce the
dependencies on asm/irq.h.
It turns out that a major cause of this is the needless include of
linux/hardirq.h into asm-generic/local.h. The patch below removes this
include, resulting in some 250 to 300 files (around half) of the kernel
then omitting asm/irq.h.
My test builds still succeed, provided two ARM files are fixed
(arch/arm/kernel/traps.c and arch/arm/mm/fault.c) - so there may be
negative impacts for this on other architectures.
Note that x86 does not include asm/irq.h nor linux/hardirq.h in its
asm/local.h, so this patch can be viewed as bringing the generic version
into line with the x86 version.
[kosaki.motohiro@jp.fujitsu.com: add #include <linux/irqflags.h> to acpi/processor_idle.c]
[adobriyan@gmail.com: fix sparc64]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This migrates from the old bitrotted kgdb stub implementation and moves
to the generic stub. In the process support for SH-2/SH-2A is also added,
which the old stub never provided.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Commit 3f5a54e371 ("ftrace: dump out ftrace
buffers to console on panic") added an ftrace buffer dumper that hooks
in to the die notifier chain and dumps out data in the oops path.
Unfortunately SH supported ftrace but didn't support DIE_OOPS, so add
that in and get it building again.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
There are other places where we want to have access to the trap/exception
number, so move out the lookup_exception_vector() helper. While we're at
it, refactor it slightly to return the vector instead.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Initial support for kprobes/kretprobes for 32-bit SH platforms.
[ General cleanup and some rework for the kretprobe hash lock. -- PFM ]
Signed-off-by: Chris Smith <chris.smith@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch is
By sh2
- Remove duplicate code
- Reduce stack usage
- Cleanup and little optimize
By sh2a
- Add missing handler(256 to 511)
- Use sh2a instructions handler
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
arch/sh/kernel/traps_32.c: In function `do_reserved_inst':
arch/sh/kernel/traps_32.c:667: error: implicit declaration of function `do_fpu_inst'
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The idea is that we want to get rid of the in/out/readb/writeb callbacks from
the machvec and replace that with simple inline read and write operations to
memory. Fast and simple for most hardware devices (think pci).
Some devices require special treatment though - like 16-bit only CF devices -
so we need to have some method to hook in callbacks.
This patch makes it possible to add a per-device trap generating filter. This
way we can get maximum performance of sane hardware - which doesn't need this
filter - and crappy hardware works but gets punished by a performance hit.
V2 changes things around a bit and replaces io access callbacks with a
simple minimum_bus_width value. In the future we can add stride as well.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch converts the unaligned access handling code to use opcode_t
instead of u16. While at it, enable unaligned access handling for sh2a.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch adds byte support to the sign extension code. Unaligned access
traps should never be generated on 8-bit io operations, but we will use this
code for trapped io and we do need byte support there.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Break out the sign extension code since it's used in multiple places.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
