parisc: Use irq_enter_rcu() to fix warning at kernel/context_tracking.c:367

Use irq*_rcu() functions to fix this kernel warning:

WARNING: CPU: 0 PID: 0 at kernel/context_tracking.c:367 ct_irq_enter+0xa0/0xd0
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.7.0-rc3-64bit+ #1037
Hardware name: 9000/785/C3700

IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000412cd758 00000000412cd75c
IIR: 03ffe01f ISR: 0000000000000000 IOR: 0000000043c20c20
CPU: 0 CR30: 0000000041caa000 CR31: 0000000000000000
ORIG_R28: 0000000000000005
IAOQ[0]: ct_irq_enter+0xa0/0xd0
IAOQ[1]: ct_irq_enter+0xa4/0xd0
RP(r2): irq_enter+0x34/0x68
Backtrace:
[<000000004034a3ec>] irq_enter+0x34/0x68
[<000000004030dc48>] do_cpu_irq_mask+0xc0/0x450
[<0000000040303070>] intr_return+0x0/0xc

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: irq: Make irq_stack_union static to avoid sparse warning

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: irq: Add irq-related function declarations

Move function declarations for do_cpu_irq_mask(), timer_interrupt() and
ipi_interrupt() to header file.

Signed-off-by: Helge Deller <deller@gmx.de>

asm-generic: Conditionally enable do_softirq_own_stack() via Kconfig.

Remove the CONFIG_PREEMPT_RT symbol from the ifdef around
do_softirq_own_stack() and move it to Kconfig instead.

Enable softirq stacks based on SOFTIRQ_ON_OWN_STACK which depends on
HAVE_SOFTIRQ_ON_OWN_STACK and its default value is set to !PREEMPT_RT.
This ensures that softirq stacks are not used on PREEMPT_RT and avoids
a 'select' statement on an option which has a 'depends' statement.

Link: https://lore.kernel.org/YvN5E%2FPrHfUhggr7@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/*: Disable softirq stacks on PREEMPT_RT.

PREEMPT_RT preempts softirqs and the current implementation avoids
do_softirq_own_stack() and only uses __do_softirq().

Disable the unused softirqs stacks on PREEMPT_RT to save some memory and
ensure that do_softirq_own_stack() is not used bwcause it is not expected.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

genirq: Add and use an irq_data_update_affinity helper

Some architectures and irqchip drivers modify the cpumask returned by
irq_data_get_affinity_mask, usually by copying in to it. This is
problematic for uniprocessor configurations, where the affinity mask
should be constant, as it is known at compile time.

Add and use a setter for the affinity mask, following the pattern of
irq_data_update_effective_affinity. This allows the getter function to
return a const cpumask pointer.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Xen bits
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220701200056.46555-7-samuel@sholland.org

parisc: Move CPU startup-related functions into .text section

If CONFIG_HOTPLUG_CPU is enabled, those functions will be run again
after bootup. So they need to reside in the .text section.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Clean up cpu_check_affinity() and drop cpu_set_affinity_irq()

The cpu_set_affinity_irq() isn't needed. Not the CPU irqs need to
change, but the slave irq chips simply need to be reprogrammed to
a new CPU irq with the txn_* functions.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Move thread_info into task struct

This implements the CONFIG_THREAD_INFO_IN_TASK option.

With this change:
- before thread_info was part of the stack and located at the beginning of the stack
- now the thread_info struct is moved and located inside the task_struct structure
- the stack is allocated and handled like the major other platforms
- drop the cpu field of thread_info and use instead the one in task_struct

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sven Schnelle <svens@stackframe.org>

softirq: Move do_softirq_own_stack() to generic asm header

To avoid include recursion hell move the do_softirq_own_stack() related
content into a generic asm header and include it from all places in arch/
which need the prototype.

This allows architectures to provide an inline implementation of
do_softirq_own_stack() without introducing a lot of #ifdeffery all over the
place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210210002513.289960691@linutronix.de

parisc: Bump 64-bit IRQ stack size to 64 KB

Bump 64-bit IRQ stack size to 64 KB.

I had a kernel IRQ stack overflow on the mx3210 debian buildd machine. This patch increases the
64-bit IRQ stack size to 64 KB. The 64-bit stack size needs to be larger than the 32-bit stack
size since registers are twice as big.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc/irq: Use irq_desc_kstat_cpu() in show_interrupts()

The irq descriptor is already there, no need to look it up again.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-parisc@vger.kernel.org
Link: https://lore.kernel.org/r/20201210194043.659522455@linutronix.de

parisc/irq: Simplify irq count output for /proc/interrupts

The SMP variant works perfectly fine on UP as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-parisc@vger.kernel.org
Link: https://lore.kernel.org/r/20201210194043.172893840@linutronix.de

parisc: Replace setup_irq() by request_irq()

request_irq() is preferred over setup_irq(). Invocations of setup_irq()
occur after memory allocators are ready.

Per tglx[1], setup_irq() existed in olden days when allocators were not
ready by the time early interrupts were initialized.

Hence replace setup_irq() by request_irq().

[1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanos

Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 153

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 or at your option any
later version this program is distributed in the hope that it will
be useful but without any warranty without even the implied warranty
of merchantability or fitness for a particular purpose see the gnu
general public license for more details you should have received a
copy of the gnu general public license along with this program if
not write to the free software foundation inc 675 mass ave cambridge
ma 02139 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 77 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.837555891@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parisc: Improve initial IRQ to CPU assignment

On parisc, each IRQ can only be handled by one CPU, and currently CPU0
is choosen as default for handling all IRQs by default.
With this patch we now assign each requested IRQ to one of the online
CPUs (and thus distribute the IRQs across all CPUs), even without an
instance of irqbalance running.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Count IPI function call interrupts

Like other platforms, count the number of IPI function call interrupts
and show it in /proc/interrupts.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Show rescheduling interrupts on SMP machines only

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Increase thread and stack size to 32kb

Since kernel 4.11 the thread and irq stacks on parisc randomly overflow
the default size of 16k. The reason why stack usage suddenly grew is yet
unknown.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.11+
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Disable further stack checks when panic occurs during stack check

Before the irq handler detects a low stack and then panics the kernel, disable
further stack checks to avoid recursive panics.

Reported-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Filter out spurious interrupts in PA-RISC irq handler

When detecting a serial port on newer PA-RISC machines (with iosapic) we have a
long way to go to find the right IRQ line, registering it, then registering the
serial port and the irq handler for the serial port. During this phase spurious
interrupts for the serial port may happen which then crashes the kernel because
the action handler might not have been set up yet.

So, basically it's a race condition between the serial port hardware and the
CPU which sets up the necessary fields in the irq sructs. The main reason for
this race is, that we unmask the serial port irqs too early without having set
up everything properly before (which isn't easily possible because we need the
IRQ number to register the serial ports).

This patch is a work-around for this problem. It adds checks to the CPU irq
handler to verify if the IRQ action field has been initialized already. If not,
we just skip this interrupt (which isn't critical for a serial port at bootup).
The real fix would probably involve rewriting all PA-RISC specific IRQ code
(for CPU, IOSAPIC, GSC and EISA) to use IRQ domains with proper parenting of
the irq chips and proper irq enabling along this line.

This bug has been in the PA-RISC port since the beginning, but the crashes
happened very rarely with currently used hardware. But on the latest machine
which I bought (a C8000 workstation), which uses the fastest CPUs (4 x PA8900,
1GHz) and which has the largest possible L1 cache size (64MB each), the kernel
crashed at every boot because of this race. So, without this patch the machine
would currently be unuseable.

For the record, here is the flow logic:
1. serial_init_chip() in 8250_gsc.c calls iosapic_serial_irq().
2. iosapic_serial_irq() calls txn_alloc_irq() to find the irq.
3. iosapic_serial_irq() calls cpu_claim_irq() to register the CPU irq
4. cpu_claim_irq() unmasks the CPU irq (which it shouldn't!)
5. serial_init_chip() then registers the 8250 port.
Problems:
- In step 4 the CPU irq shouldn't have been registered yet, but after step 5
- If serial irq happens between 4 and 5 have finished, the kernel will crash

Signed-off-by: Helge Deller <deller@gmx.de>

parisc/irq: Use access helper irq_data_get_affinity_mask()

Use access helper irq_data_get_affinity_mask() to hide implementation
details of struct irq_desc.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Link: http://lkml.kernel.org/r/1433145945-789-24-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parisc: fix up obsolete cpu function usage.

Thanks to spatch.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org

parisc: Validate online cpus in irq_set_affinity() callbacks

The [user space] interface does not filter out offline cpus. It merily
guarantees that the mask contains at least one online cpu.

So the selector in the irq chip implementation needs to make sure to
pick only an online cpu because otherwise:

Offline Core 1
Set affinity to 0xe (is valid due to online mask 0xd)
cpumask_first will pick core 1, which is offline

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Link: http://lkml.kernel.org/r/20140304203100.859489993@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parisc: do not count IPI calls twice

The number of IPI calls is already visible as per-cpu IPI irq counters
in/proc/cpuinfo, so let's drop this additional counting.

This partly reverts:
cd85d55 parisc: more irq statistics in /proc/interrupts

Signed-off-by: Helge Deller <deller@gmx.de>

irq: Consolidate do_softirq() arch overriden implementations

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: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Frederic 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>

parisc: fix irq stack on UP and SMP

The logic to detect if the irq stack was already in use with
raw_spin_trylock() is wrong, because it will generate a "trylock failure
on UP" error message with CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=y.

arch_spin_trylock() can't be used either since in the CONFIG_SMP=n case
no atomic protection is given and we are reentrant here. A mutex didn't
worked either and brings more overhead by turning off interrupts.

So, let's use the fastest path for parisc which is the ldcw instruction.

Counting how often the irq stack was used is pretty useless, so just
drop this piece of code.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: show number of FPE and unaligned access handler calls in /proc/interrupts

Show number of floating point assistant and unaligned access fixup
handler in /proc/interrupts file.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: implement irq stacks - part 2 (v2)

This patch fixes few build issues which were introduced with the last
irq stack patch, e.g. the combination of stack overflow check and irq
stack.

Furthermore we now do proper locking and change the irq bh handler
to use the irq stack as well.

In /proc/interrupts one now can monitor how huge the irq stack has grown
and how often it was preferred over the kernel stack.

IRQ stacks are now enabled by default just to make sure that we not
overflow the kernel stack by accident.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: tlb flush counting fix for SMP and UP

Fix up build error on UP and show correctly number of function call
(ipi) irqs.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: more irq statistics in /proc/interrupts

Add framework and initial values for more fine grained statistics in
/proc/interrupts.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: implement irq stacks

Default kernel stack size on parisc is 16k. During tests we found that the
kernel stack can easily grow beyond 13k, which leaves 3k left for irq
processing.

This patch adds the possibility to activate an additional stack of 16k per CPU
which is being used during irq processing. This implementation does not yet
uses this irq stack for the irq bh handler.

The assembler code for call_on_stack was heavily cleaned up by John
David Anglin.

CC: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: add kernel stack overflow check

Add the CONFIG_DEBUG_STACKOVERFLOW config option to enable checks to
detect kernel stack overflows.

Stack overflows can not be detected reliable since we do not want to
introduce too much overhead.

Instead, during irq processing in do_cpu_irq_mask() we check kernel
stack usage of the interrupted kernel process. Kernel threads can be
easily detected by checking the value of space register 7 (sr7) which
is zero when running inside the kernel.

Since THREAD_SIZE is 16k and PAGE_SIZE is 4k, reduce the alignment of
the init thread to the lower value (PAGE_SIZE) in the kernel
vmlinux.ld.S linker script.

Signed-off-by: Helge Deller <deller@gmx.de>

parisc: remove IRQF_DISABLED

People are playing odd games with IRQF_DISABLED, remove it.

Its not reliable, since shared interrupt lines could disable it for you,
and its possible and allowed for archs to disable IRQs to limit IRQ nesting.

Therefore, simply mandate that _ALL_ IRQ handlers are run with IRQs disabled.

[ This _should_ not break anything, since we've mandated that IRQ handlers
_must_ be able to deal with this for a _long_ time ]

IRQ handlers should be fast, no if buts and any other exceptions. We also have
plenty instrumentation to find any offending IRQ latency sources.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: don't claim cpu irqs more than once

The CPU irqs (timer and IPI) are not shared and only need to be claimed once.
A mismatch error occurs if they are claimed more than once.

Signed-off-by: John David Anglin <dave.anglin@nrc-cnrc.gc.ca>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Use irq_to_desc() in show_interrupts()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parisc: Convert irq namespace

Convert to the new function names. Scripted with coccinelle.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: linux-parisc@vger.kernel.org

parisc: Convert the final irq bits

1) As promised in the comment, the core does not copy cpumask anymore
when the arch code returns -EINVAL

2) Get the per cpu information from irq_data

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: linux-parisc@vger.kernel.org

[PARISC] Convert to new irq_chip functions

Convert all the parisc driver interrupt handlers (dino, eisa, gsc,
iosapic and superio) as well as the cpu interrupts. Prepare
show_interrupts for GENERIC_HARDIRQS_NO_DEPRECATED and finally selects
that Kconfig option

[jejb: compile and testing fixes]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[PARISC] fix per-cpu flag problem in the cpu affinity checkers

The CHECK_IRQ_PER_CPU is wrong, it should be checking
irq_to_desc(irq)->status not just irq.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

parisc: convert the rest of the irq handlers to simple/percpu

The generic conversion eliminates the spurious no_ack and no_end
routines, converts all the cascaded handlers to handle_simple_irq() and
makes iosapic use a modified handle_percpu_irq() to become the same as
the CPU irq's. This isn't an essential change, but it eliminates the
mask/unmask overhead of handle_level_irq().

Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

parisc: fix dino/gsc interrupts

The essential problem we're currently having is that dino (and gsc) is a
cascaded CPU interrupt. Under the old __do_IRQ() handler, our CPU
interrupts basically did an ack followed by an end. In the new scheme,
we replaced them with level handlers which do a mask, an ack and then an
unmask (but no end). Instead, with the renaming of end to eoi, we
actually want to call the percpu flow handlers, because they actually
have all the characteristics we want.

This patch does the conversion and gets my C360 booting again.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

parisc: kill __do_IRQ

Signed-off-by: Kyle McMartin <kyle@redhat.com>

parisc: convert iosapic interrupts to proper flow handlers

Shift the ->end call (cpu eoi) from __do_IRQ into our
unmask handler. Also nuke some redundant code.

Signed-off-by: Kyle McMartin <kyle@redhat.com>

parisc: convert cpu interrupts to proper flow handlers

Only major change is renaming functions to match the conventions
expected by the generic irq code.

Signed-off-by: Kyle McMartin <kyle@redhat.com>

parisc: lay groundwork for killing __do_IRQ

Use proper accessors and handlers for generic irq cleanups. We just
call back into __do_IRQ through desc->handler now, and remove the
explicit calls.

Signed-off-by: Kyle McMartin <kyle@redhat.com>

parisc: Fixup last users of irq_chip->typename

The typename member of struct irq_chip was kept for migration purposes
and is obsolete since more than 2 years. Fix up the leftovers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

genirq: Convert irq_desc.lock to raw_spinlock

Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>

parisc: convert to asm-generic/hardirq.h

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

parisc: remove obsolete hw_interrupt_type

The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t) have
been kept around for migration reasons. After more than two years it's
time to remove them finally.

This patch cleans up one of the remaining users. When all such patches
hit mainline we can remove the defines and typedefs finally.

Impact: cleanup

Convert the last remaining users to struct irq_chip and remove the
define.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

parisc: fix irq compile bugs in arch/parisc/kernel/irq.c

Fix miscompilation in arch/parisc/kernel/irq.c:
123: warning: passing arg 1 of `cpumask_setall' from incompatible pointer type
141: warning: passing arg 1 of `cpumask_copy' from incompatible pointer type
300: warning: passing arg 1 of `cpumask_copy' from incompatible pointer type
357: warning: passing arg 2 of `cpumask_copy' from incompatible pointer type

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

irq: change ->set_affinity() to return status

according to Ingo, change set_affinity() in irq_chip should return int,
because that way we can handle failure cases in a much cleaner way, in
the genirq layer.

v2: fix two typos

[ Impact: extend API ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: linux-arch@vger.kernel.org
LKML-Reference: <49F654E9.4070809@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

cpumask: prepare for iterators to only go to nr_cpu_ids/nr_cpumask_bits.: parisc

Impact: cleanup, futureproof

In fact, all cpumask ops will only be valid (in general) for bit
numbers < nr_cpu_ids. So use that instead of NR_CPUS in various
places.

This is always safe: no cpu number can be >= nr_cpu_ids, and
nr_cpu_ids is initialized to NR_CPUS at boot.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

parisc: convert cpu_check_affinity to new cpumask api

cpumask arg to the affinity function is now const, sort
that out through the irq_desc implementations.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

parisc: fix use of new cpumask api in irq.c

cpumask api needs to take a pointer to irq_desc[cpu].affinity

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

parisc: update parisc for new irq_desc

Impact: cleanup, update to new cpumask API

Irq_desc.affinity and irq_desc.pending_mask are now cpumask_var_t's
so access to them should be using the new cpumask API.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

irq: update all arches for new irq_desc

Impact: cleanup, update to new cpumask API

Irq_desc.affinity and irq_desc.pending_mask are now cpumask_var_t's
so access to them should be using the new cpumask API.

Signed-off-by: Mike Travis <travis@sgi.com>

sparseirq: use kstat_irqs_cpu instead

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: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parisc: Replace NR_CPUS in parisc code

parisc: Replace most arrays sized by NR_CPUS with percpu variables.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

parisc: trivial fixes

trivial fixes:
- use KERN_WARNING for printk()
- use BUG_ON() instead of "if (xx) BUG();"

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

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cpumask: make irq_set_affinity() take a const struct cpumask

Impact: change existing irq_chip API

Not much point with gentle transition here: the struct irq_chip's
setaffinity method signature needs to change.

Fortunately, not widely used code, but hits a few architectures.

Note: In irq_select_affinity() I save a temporary in by mangling
irq_desc[irq].affinity directly. Ingo, does this break anything?

(Folded in fix from KOSAKI Motohiro)

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Acked-by: Ingo Molnar <mingo@redhat.com>
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: jeremy@xensource.com
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>

[PARISC] timer interrupt should not be IRQ_DISABLED

The timer interrupt had accidentally been marked IRQ_DISABLED since
IRQ_PER_CPU had been OR-ed in, instead of set. This had been working
by accident for quite a while.

Commit c642b8391cf8efc3622cc97329a0f46e7cbb70b8 changed the behaviour of
IRQ_PER_CPU interrupts, which previously weren't checked for IRQ_DISABLED.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

[PARISC] remove global_ack_eiem

Kudos to Thibaut Varene for spotting the (mis)use of appropriately named
global_ack_eiem. This took a long time to figure out and both insight
from myself, Kyle McMartin, and James Bottomley were required to narrow
down which bit of code could have this race condition.

The symptom was interrupts stopped getting delivered while some workload
was generating IO interrupts on two different CPUs. One of the interrupt
sources would get masked off and stay unmasked. Problem was global_ack_eiem
was accessed with read/modified/write sequence and not protected by
a spinlock.

PA-RISC doesn't need a global ack flag though. External Interrupts
are _always_ delivered to a single CPU (except for "global broadcast
interrupt" which AFAIK currently is not used.) So we don't have to worry
about any given IRQ vector getting delivered to more than one CPU.

Tested on a500 and rp34xx boxen. rsync to/from gsyprf11 (a500)
would lock up the box since NIC (tg3) interrupt and SCSI (sym2)
were on "opposite" CPUs (2 CPU system). Put them on the same CPU
or apply this patch and 10GB of data would rsync completely.

Please apply the following critical patch.

thanks,
grant

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Acked-by: Thibaut VARENE <T-Bone@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

Add IRQF_IRQPOLL flag on parisc

Add IRQF_IRQPOLL to the timer interrupt on parisc.

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Grant Grundler <grundler@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PARISC] use fls_long in irq.c


Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Use set_irq_regs

Actually set the irq_regs pointer.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>

Build fixes for struct pt_regs removal

Signed-off-by: Matthew Wilcox <matthew@wil.cx>

[PARISC] Allow nested interrupts

Our prior mode of operation didn't allow nested interrupts
because it makes the interrupt code much simpler. However,
nested interrupts are better for latency.

This code uses the EIEM register to simulate level interrupts
and thus achieve nesting.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Fix up parisc irq handling for genirq changes

Clean up enough to get things compiling again in the interim.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PATCH] irq-flags: PARISC: Use the new IRQF_ constants

Use the new IRQF_ constants and remove the SA_INTERRUPT define

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[PATCH] genirq: add ->retrigger() irq op to consolidate hw_irq_resend()

Add ->retrigger() irq op to consolidate hw_irq_resend() implementations.
(Most architectures had it defined to NOP anyway.)

NOTE: ia64 needs testing. i386 and x86_64 tested.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] genirq: cleanup: merge irq_affinity[] into irq_desc[]

Consolidation: remove the irq_affinity[NR_IRQS] array and move it into the
irq_desc[NR_IRQS].affinity field.

[akpm@osdl.org: sparc64 build fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] genirq: rename desc->handler to desc->chip

This patch-queue improves the generic IRQ layer to be truly generic, by adding
various abstractions and features to it, without impacting existing
functionality.

While the queue can be best described as "fix and improve everything in the
generic IRQ layer that we could think of", and thus it consists of many
smaller features and lots of cleanups, the one feature that stands out most is
the new 'irq chip' abstraction.

The irq-chip abstraction is about describing and coding and IRQ controller
driver by mapping its raw hardware capabilities [and quirks, if needed] in a
straightforward way, without having to think about "IRQ flow"
(level/edge/etc.) type of details.

This stands in contrast with the current 'irq-type' model of genirq
architectures, which 'mixes' raw hardware capabilities with 'flow' details.
The patchset supports both types of irq controller designs at once, and
converts i386 and x86_64 to the new irq-chip design.

As a bonus side-effect of the irq-chip approach, chained interrupt controllers
(master/slave PIC constructs, etc.) are now supported by design as well.

The end result of this patchset intends to be simpler architecture-level code
and more consolidation between architectures.

We reused many bits of code and many concepts from Russell King's ARM IRQ
layer, the merging of which was one of the motivations for this patchset.

This patch:

rename desc->handler to desc->chip.

Originally i did not want to do this, because it's a big patch. But having
both "desc->handler", "desc->handle_irq" and "action->handler" caused a
large degree of confusion and made the code appear alot less clean than it
truly is.

I have also attempted a dual approach as well by introducing a
desc->chip alias - but that just wasnt robust enough and broke
frequently.

So lets get over with this quickly. The conversion was done automatically
via scripts and converts all the code in the kernel.

This renaming patch is the first one amongst the patches, so that the
remaining patches can stay flexible and can be merged and split up
without having some big monolithic patch act as a merge barrier.

[akpm@osdl.org: build fix]
[akpm@osdl.org: another build fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PARISC] Make redirecting irq messages less noisy

Make the "redirecting irq" message to not display on the console by
setting the severity to KERN_DEBUG. The console was basically unusable.

Signed-off-by: Ryan Bradetich <rbrad@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] irq_affinityp[] only available for SMP builds

irq_affinityp[] only available for SMP builds, make code that uses
it conditional on CONFIG_SMP.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Add IRQ affinities

This really only adds them for the machines I can check SMP on, which
is CPU interrupts and IOSAPIC (so not any of the GSC based machines).

With this patch, irqbalanced can be used to maintain irq balancing.
Unfortunately, irqbalanced is a bit x86 centric, so it doesn't do an
incredibly good job, but it does work.

Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Fix uniprocessor build by dummying smp_send_all_nop()

Since irq.c uses smp_send_all_nop, we must define it for UP builds
as well. Make it a static inline so it gets optimized away. This forces
irq.c to include <asm/smp.h> though.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Fix our interrupts not to use smp_call_function

Fix our interrupts not to use smp_call_function

On K and D class smp, the generic code calls this under an irq
spinlock, which causes the WARN_ON() message in smp_call_function()
(and is also illegal because it could deadlock).

The fix is to use a new scheme based on the IPI_NOP.

Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Disable nesting of interrupts

Disable nesting of interrupts - still has holes

The offending sequence starts out like this:
1) take external interrupt
2) set_eiem() to only allow TIMER_IRQ; local interrupts still disabled
3) read the EIRR to get a "list" of pending interrupts
4) clear EIRR of pending interrupts we intend to handle
5) call __do_IRQ() to handle IRQ.
6) handle_IRQ_event() enables local interrupts (I-Bit)
7) take a timer interrupt
8) read EIRR to get a new list of pending interrupts
9) clear EIRR of pending interrupts we just read
10) handle pending interrupts found in (8)
11) set_eiem(cpu_eiem) and return
[ TROUBLE! all enabled CPU IRQs are unmasked. }
12) handle remaining interrupts pending from (3)
e.g. call __do_IRQ() -> handle_IRQ_event()..etc
[ TROUBLE! call to handle_IRQ_event() can now enable *any* IRQ. }
13) set_eiem(cpu_eiem) and return

The problem is we now get into ugly race conditions with Timer and IPI
interrupts at this point. I'm not exactly sure what happens when
things go wrong (perhaps nest calls to IPI or timer interrupt?).
But I'm certain it's not good.

This sequence will break sooner if (10) would accidentally leave
interrupts enabled.

I'm pretty sure the right answer is now to make cpu_eiem
a per CPU variable since all external interrupts on parisc
are per CPU. This means we will NOT need to send an IPI to
every CPU in the system when enabling or disabling an IRQ
since only one CPU needs to change it's EIEM.

Thanks to James Bottomley for (once again) pointing out the problem.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

[PARISC] Make sure timer and IPI execute with interrupts disabled

Fix a longstanding smp bug

The problem is that both the timer and ipi interrupts are being called
with interrupts enabled, which isn't what anyone is expecting.

The IPI issue has just started to show up by causing a BUG_ON in the
slab debugging code. The timer issue never shows up because there's an
eiem work around in our irq.c

The fix is to label both these as SA_INTERRUPT which causes the generic
irq code not to enable interrupts.

I also suspect the smp_call_function timeouts we're seeing might be
connected with the fact that we disable IPIs when handling any other
type of interrupt. I've put a WARN_ON in the code for executing
smp_call_function() with IPIs disabled.

Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!