Emulate single stepping in KGDB on MN10300 by way of temporary breakpoint
insertion.  These breakpoints are never actually seen by KGDB, and will overlay
KGDB's own breakpoints.

The breakpoints are removed by switch_to() and reinstalled on switching back so
that if preemption occurs, the preempting task doesn't hit them (though it will
still hit KGDB's regular breakpoints).  If KGDB is reentered for any reason,
then the single step breakpoint is completely erased and must be set again by
the debugger.

We take advantage of the fact that KGDB will effectively halt all other CPUs
whilst this CPU is single-stepping to avoid SMP problems.

If the single-stepping task is preempted and killed without KGDB being
reinvoked, then the breakpoint(s) will be cleared and KGDB will be jumped back
into.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Generalise the kernel debugger hook for notification of halt, reboot or power
off.  This is used by gdbstub to tell the debugger it is exiting.  This will be
useful for KGDB too.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Create generic kernel debugger hooks in the MN10300 arch and make gdbstub use
them.  This is a preparation for KGDB support.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Create general kernel debugger cache flushing for MN10300 and get rid of the
old stuff that gdbstub was using.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Introduce a general config option for kernel debugger hooks so that both
gdbstub and kgdb can use it and add a header file for both debuggers to use.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

The icache invalidate functions should disable the icache on AM33 and wait for
it to quiesce before attempting to invalidate it, and should then wait for it
to quiesce again before reenabling it, but on AM34 they should invalidate
directly.  The same goes for the dcache invalidation, but this isn't used much.

Whilst we're at it, this can be wrapped in assembler macros to remove duplicate
code.

The AM33 manual states that:

	An operation that invalidates the cache, switches the writing mode, or
	changes the way mode must be performed after disabling the cache,
	checking the busy bit, and confirming that the cache is not in
	operation.

for the dcache [sec 2.8.3.2.1].  This is not stated so for the icache [sec
2.8.3.1.1] but the example code there suggests that it is.

Whilst the AM34 manual states that the cache must be disabled for both the
icache [sec 1.8.3.2.1] and the dcache [sec 1.8.3.2.1], the Panasonic hardware
engineers say the manual is wrong and that disabling the caches for
invalidation is wrong.

Furthermore, they say that disabling the caches on the AM34 whilst running an
SMP kernel can lead to incoherency between the various CPU caches and should
thus be avoided.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Restrict single-stepping through the kernel using gdbstub to non-preemptable
non-SMP configs as gdbstub has to do software single-stepping by means of
temporary breakpoints.  Hardware single-stepping is unavailable as Panasonic
have not sufficiently documented the interface to it.

Software single-stepping through preemptable or SMP kernels runs into problems
as it makes it much more likely that the wrong thread will hit the temporary
breakpoints.  It seems impractical to work around the problem for the most
part.  It could be possible to make a UP preemptable kernel switch temporary
breakpoints in and out in switch_to().
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Clear the interrupt mask registers of ASB2364 peripherals before enabling
interrupts so that any peripherals that weren't dealt with by the bootloader
after a reboot (if there was one) won't cause an interrupt storm when
interrupts are first enabled before the drivers are initialised.

Also, attempt to reset the peripherals attached to the FPGA.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Fix the ASB2364 gdbport UART register definitions.  These registers are
actually 2 bytes apart, not 4 (which the ASB2303 and ASB2305 are).
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Fix the definition of the ASB2364 FPGA IRQ detect registers.  They accidentally
got defined to be the same as the mask registers when the patches were being
ported to the upstream kernel.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

All chips converted.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Select HAVE_GENERIC_HARDIRQS rather than GENERIC_HARDIRQS in MN10300's main
Kconfig file to avoid this warning:

warning: (MN10300) selects GENERIC_HARDIRQS which has unmet direct dependencies (HAVE_GENERIC_HARDIRQS)
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

No users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

irq_chip.end is obsolete with the removal of __do_IRQ().
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Use clockevents_calc_mult_shift() instead of the homebrewn function in
mn10300/kernel/time.c.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NJohn Stultz <johnstul@us.ibm.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

clocksource_register_hz() calculates the shift/mult pair for the
clocksource. Remove the mn10300 duplicate implementation.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NJohn Stultz <johnstul@us.ibm.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

mn10300 implements clocksource and clockevents and selects them
unconditionally in Kconfig. Remove the stale code which seems to be a
leftover of the conversion. Cleanup the configuration switches as well.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NJohn Stultz <johnstul@us.ibm.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

atomic_read() needs to ensure that it emits a load (which it can do by using
ACCESS_ONCE()).
Reported-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

The invalidate-only versions of flush_icache_*range() are trying sending the
SMP_ICACHE_INV_FLUSH_RANGE IPI command in SMP kernels when they should be
sending SMP_ICACHE_INV_RANGE as the former does not exist.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Using __get_user_check(x, ptr++, size) leads to double increment of pointer.
This macro uses the macro get_user directly, which itself is used in this way
(get_user(x, ptr++)) in some functions of the kernel. The patch fixes the
error.
Reported-by: NTkhai Kirill <tkhai@yandex.ru>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Only one CPU gets the timer interrupt so mn10300_last_tsc does not
need to be protected by xtime lock. Remove xtime lovking and use
xtime_update() which does the locking itself.
Signed-off-by: NTorben Hohn <torbenh@gmx.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
LKML-Reference: <20110127150011.23248.62040.stgit@localhost>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Currently percpu readmostly subsection may share cachelines with other
percpu subsections which may result in unnecessary cacheline bounce
and performance degradation.

This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR()
linker macros, makes each arch linker scripts specify its cacheline
size and use it to align percpu subsections.

This is based on Shaohua's x86 only patch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Shaohua Li <shaohua.li@intel.com>

No functional change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NDavid Howells <dhowells@redhat.com>

All architectures are finally converted. Remove the cruft.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Michal Simek <monstr@monstr.eu>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>

The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.

This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel.  A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).

Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NDavid Woodhouse <david.woodhouse@intel.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For arch which needs USE_GENERIC_SMP_HELPERS, it has to select
USE_GENERIC_SMP_HELPERS, rather than leaving a choice to user, since they
don't provide their own implementions.

Also, move on_each_cpu() to kernel/smp.c, it is strange to put it in
kernel/softirq.c.

For arch which doesn't use USE_GENERIC_SMP_HELPERS, e.g.  blackfin, only
on_each_cpu() is compiled.
Signed-off-by: NAmerigo Wang <amwang@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Occasionally the system gets into a state where the CMOS clock has gotten
slightly ahead of current time and the periodic update of RTC fails.  The
message is a nuisance and repeats spamming the log.

  See: http://www.ntp.org/ntpfaq/NTP-s-trbl-spec.htm#Q-LINUX-SET-RTC-MMSS

Rather than just removing the message, make it show only once and reduce
severity since it indicates a normal and non urgent condition.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=25702Reported-by: NMartin Ettl <ettl.martin@gmx.de>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The cnt32_to_63 algorithm relies on proper counter data evaluation
ordering to work properly. This was missing from the provided
documentation.

Let's augment the documentation with the missing usage constraint and
fix the only instance that got it wrong.
Signed-off-by: NNicolas Pitre <nico@fluxnic.net>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the name of interrupt mask alteration function (ie the
local_change_intr_mask_level() fn) called in gdbstub to have an arch_
prefix to match the definition in asm/irqflags.h.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement asm/syscall.h for the MN10300 arch.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use new 'datap' variable in order to remove unnecessary castings.
Also remove checking @addr less than 0 because @addr is now unsigned.
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: NRoland McGrath <roland@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Christoph reported a nice splat which illustrated a race in the new stack
based kmap_atomic implementation.

The problem is that we pop our stack slot before we're completely done
resetting its state -- in particular clearing the PTE (sometimes that's
CONFIG_DEBUG_HIGHMEM).  If an interrupt happens before we actually clear
the PTE used for the last slot, that interrupt can reuse the slot in a
dirty state, which triggers a BUG in kmap_atomic().

Fix this by introducing kmap_atomic_idx() which reports the current slot
index without actually releasing it and use that to find the PTE and delay
the _pop() until after we're completely done.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: NChristoph Hellwig <hch@infradead.org>
Acked-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>