All arch overriden implementations of do_softirq() share the following
common code: disable irqs (to avoid races with the pending check),
check if there are softirqs pending, then execute __do_softirq() on
a specific stack.

Consolidate the common parts such that archs only worry about the
stack switch.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@au1.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@au1.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Andrew Morton <akpm@linux-foundation.org>

Now that legacy pre-allocation is done away with, we can just use the
generic stub in kernel/softirq.c.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Everything is using sparseirq these days, so we have no need to
arbitrarily size nr_irqs ahead of time. The legacy IRQ pre-allocation
likewise has no meaning for us, so that's killed off too. We now depend
on nr_irqs expansion by the generic hardirq layer instead.

It's also worth noting that the majority of boards had completely bogus
values for their nr_irqs relative to their CPU and configurations, so
this ends up correcting behaviour for quite a few platforms.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Follows the powerpc change, for much the same rationale.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Trivial conversion, simply encapsulate the NMI stats in the arch code.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This fixes up the __cpu_disable() path's IRQ migration for the
irq_data changes.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently the irq chip is found through the irq_desc, but as this is
going away convert over to an irq_data lookup instead.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Now that the genirq code provides an IRQ bitmap of its own and the
necessary API to manipulate it, there's no need to keep our own version
around anymore.

In the process we kill off some unused IRQ reservation code, with future
users now having to tie in to the genirq API as normal.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

sparse irq sets up NR_IRQS_LEGACY irq descriptors and archs then go
ahead and allocate more.

Use the unused return value of arch_probe_nr_irqs() to let the
architecture return the number of early allocations. Fix up all users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Many interrupts that share a single mask source but are on different
hardware vectors will have an associated register tied to an INTEVT that
denotes the precise cause for the interrupt exception being triggered.

This introduces the concept of IRQ subgroups in the intc core, where
a virtual IRQ map is constructed for each of the pre-defined cause bits,
and a higher level chained handler takes control of the parent INTEVT.
This enables CPUs with heavily muxed IRQ vectors (especially across
disjoint blocks) to break things out in to a series of managed chained
handlers while being able to dynamically lookup and adopt the IRQs
created for them.

This is largely an opt-in interface, requiring CPUs to manually submit
IRQs for subgroup splitting, in addition to providing identifiers in
their enum maps that can be used for lazy lookup via the radix tree.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds preliminary support for CPU hotplug for SH SMP systems.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This implements support for hardware-managed IRQ balancing as implemented
by SH-X3 cores (presently only hooked up for SH7786, but can probably be
carried over to other SH-X3 cores, too).

CPUs need to specify their distribution register along with the mask
definitions, as these follow the same format. Peripheral IRQs that don't
opt out of balancing will be automatically distributed at the whim of the
hardware block, while each CPU needs to verify whether it is handling the
IRQ or not, especially before clearing the mask.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NIngo Molnar <mingo@elte.hu>

Different CPUs will have different starting vectors, with varying
amounts of reserved or unusable vector space prior to the first slot.
This introduces a legacy vector reservation system that inserts itself in
between the CPU vector map registration and the platform specific IRQ
setup. This works fine in practice as the only new vectors that boards
need to establish on their own should be dynamically allocated rather
than arbitrarily assigned. As a plus, this also makes all of the
converted platforms sparseirq ready.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds an __irq_entry annotation for do_IRQ() so that the IRQ
annotation in the function graph tracer works as advertized. We already
have the IRQENTRY section wired up, so this is just a trivial addition
to actually make use of it.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This plugs in support for NMI counting per-CPU via irq_cpustat_t.
Modelled after the x86 implementation.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This patch changes the remaining direct references to
.bss.page_aligned in C and assembly code to use the macros in
include/linux/linkage.h.
Signed-off-by: NTim Abbott <tabbott@ksplice.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

This implements support for NMI debugging that was shamelessly copied
from the avr32 port. A bit of special magic is needed in the interrupt
exception path given that the NMI exception handler is stubbed in to the
regular exception handling table despite being reported in INTEVT. So we
mangle the lookup and kick off an EXPEVT-style exception dispatch from
the INTEVT path for exceptions that do_IRQ() has no chance of handling.
As a result, we also drop the evt2irq() conversion from the do_IRQ() path
and just do it in assembly.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This patch changes the way in which "multi-evt" interrups are handled.
The intc_evt2irq_table and related intc_evt2irq() have been removed and
the "redirecting" handler is installed for the coupled interrupts.

Thanks to that the do_IRQ() function don't have to use another level
of indirection for all the interrupts...
Signed-off-by: NPawel Moll <pawel.moll@st.com>
Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This moves the initialization over to an early_initcall(). This fixes up
some lockdep interaction issues. At the same time, kill off some
superfluous locking in the init path.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This is a first cut at a generic DWARF unwinder for the kernel. It's
still lacking DWARF64 support and the DWARF expression support hasn't
been tested very well but it is generating proper stacktraces on SH for
WARN_ON() and NULL dereferences.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

STACK_DEBUG ties in to mcount in order to do function-granular stack
overflow checks as opposed to lazily checking from IRQ context. As the
default is nohz, the frequency of overflow checking is too irregular to
catch much useful information, and so the mcount approach employed by
sparc64 is adopted instead.

This kills off the old check entirely from the do_IRQ() path and now
adopts CONFIG_MCOUNT instead.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This is just a simple arch_probe_nr_irqs() stub that wraps to the
platform defined number of IRQs. This can be made gradually more
intelligent based on what we can infer from the INTC tables and so on.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This converts a few places that were using the old irq_desc[] array over
to the shiny new irq_to_desc() helper. Preperatory work for sparse irq
support.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Instead of keeping the single vector -> single linux irq mapping
we extend the intc code to support merging of vectors to a single
linux irq. This helps processors such as sh7750, sh7780 and sh7785
which have more vectors than masking ability. With this patch in
place we can modify the intc tables to use one irq per maskable
irq source. Please note the following:

 - If multiple vectors share the same enum then only the
   first vector will be available as a linux irq.

 - Drivers may need to be rewritten to get pending irq
   source from the hardware block instead of irq number.

This patch together with the sh7785 specific intc tables solves
DMA controller irq issues related to buggy interrupt masking.
Reported-by: NYoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: NMagnus Damm <damm@igel.co.jp>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Impact: build fix

Ingo Molnar wrote:

> tip/arch/blackfin/kernel/irqchip.c: In function 'show_interrupts':
> tip/arch/blackfin/kernel/irqchip.c:85: error: 'struct kernel_stat' has no member named 'irqs'
> make[2]: *** [arch/blackfin/kernel/irqchip.o] Error 1
> make[2]: *** Waiting for unfinished jobs....
>

So could move kstat_irqs array to irq_desc struct.

(s390, m68k, sparc) are not touched yet, because they don't support genirq
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This follows the sparc changes a439fe51.

Most of the moving about was done with Sam's directions at:

http://marc.info/?l=linux-sh&m=121724823706062&w=2

with subsequent hacking and fixups entirely my fault.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Add a proper prototype for __do_softirq() in include/linux/interrupt.h
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reported-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Caught by the surprisingly not-entirely-useless 'includecheck'.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

While using separate IRQ stacks can cut down on stack consumption,
many users can also use 4k stacks directly without the additional
need of separate stacks for soft and hardirqs.

With this split, we support the same rationale for 4KSTACKS as
m68knommu, with the IRQSTACKS abstraction as per ppc64.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

As noted by Christoph Hellwig, pktgen was the only user so
it can now be removed.

[ Add missing cases caught by Adrian Bunk. -DaveM ]
Signed-off-by: NRobert Olsson <robert.olsson@its.uu.se>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch unifies the cpu specific interrupt setup functions for
interrupt controller blocks such as ipr, intc2 and intc. There is no
point in having separate functions for each interrupt controller, so
let's clean this up.
Signed-off-by: NMagnus Damm <damm@igel.co.jp>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Use the newly added .bss.page_aligned section for aligning the stacks
rather than THREAD_SIZE.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Each board sets the total number of IRQs that it's interested in via
the machvec. Previously we cared about the off vs on-chip IRQ range,
but any code relying on that is long dead. Set NR_IRQS to something
sensible given the vector range, and allow boards to cap it if they
really care.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

SH-3 and SH-4 were trampling the register, and SH-2 wasn't even
setting it in the first place. This ended up with some rather
broken behaviour in the sysrq show_regs().
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The following moves the creation of IPR interupts into setup-7750.c
and updates a few other things to make it all work after the "Drop
CPU subtype IRQ headers" commit. It boots and runs fine on my titan
board.

 - adds an ipr_idx to the ipr_data and uses a function in the subtype
   code to calculate the address of the IPR registers

 - adds a function to enable individual interrupt mode for externals
   in the subtype code and calls that from the titan board code
   instead of doing it directly.

 - I changed the shift in the ipr_data to be the actual # of bits to
   shift, instead of the numnber / 4 - made it easier to match with
   the manual.
Signed-off-by: NJamie Lenehan <lenehan@twibble.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

There was a clobber issue with the register we were saving
the stack in, so we switch to a register that we handle in
the clobber list properly already.

This also follows the x86 changes for allowing the softirq
checks from hardirq context.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This fixes up the kernel for gcc4. The existing exception handlers
needed some wrapping for pt_regs access, acessing the registers
via a RELOC_HIDE() pointer.

The strcpy() issues popped up here too, so add -ffreestanding and
kill off the symbol export.
Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>