Commit graph

142 commits

Author SHA1 Message Date
Jinjie Ruan
6678ae1918 genirq: Reuse irq_is_nmi()
Move irq_is_nmi() to the internal header file and reuse it all over the
place.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240423024037.3331215-1-ruanjinjie@huawei.com
2024-04-24 20:42:57 +02:00
Bitao Hu
25a4a01511 genirq: Avoid summation loops for /proc/interrupts
show_interrupts() unconditionally accumulates the per CPU interrupt
statistics to determine whether an interrupt was ever raised.

This can be avoided for all interrupts which are not strictly per CPU
and not of type NMI because those interrupts provide already an
accumulated counter. The required logic is already implemented in
kstat_irqs().

Split the inner access logic out of kstat_irqs() and use it for
kstat_irqs() and show_interrupts() to avoid the accumulation loop
when possible.

Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Liu Song <liusong@linux.alibaba.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240411074134.30922-4-yaoma@linux.alibaba.com
2024-04-12 17:08:05 +02:00
Bitao Hu
86d2a2f51f genirq: Convert kstat_irqs to a struct
The irq_desc::kstat_irqs member is a per-CPU variable of type int, which is
only capable of counting. A snapshot mechanism for interrupt statistics
will be added soon, which requires an additional variable to store the
snapshot.

To facilitate expansion, convert kstat_irqs here to a struct containing
only the count.

Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240411074134.30922-2-yaoma@linux.alibaba.com
2024-04-12 17:08:05 +02:00
YueHaibing
51a5acce71 genirq: Remove unused extern declaration
commit 3795de236d ("genirq: Distangle kernel/irq/handle.c")
left behind this.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230720143625.29176-1-yuehaibing@huawei.com
2023-07-31 17:27:16 +02:00
Vincent Whitchurch
e2c12739cc genirq: Prevent nested thread vs synchronize_hardirq() deadlock
There is a possibility of deadlock if synchronize_hardirq() is called
when the nested threaded interrupt is active.  The following scenario
was observed on a uniprocessor PREEMPT_NONE system:

 Thread 1                      Thread 2

 handle_nested_thread()
  Set INPROGRESS
  Call ->thread_fn()
   thread_fn goes to sleep

                              free_irq()
                               __synchronize_hardirq()
                                Busy-loop forever waiting for INPROGRESS
                                to be cleared

The INPROGRESS flag is only supposed to be used for hard interrupt
handlers.  Remove the incorrect usage in the nested threaded interrupt
case and instead re-use the threads_active / wait_for_threads mechanism
to wait for nested threaded interrupts to complete.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613-genirq-nested-v3-1-ae58221143eb@axis.com
2023-07-31 17:24:22 +02:00
Thomas Gleixner
f121ab7f4a irqchip updates for 6.5
- A number of Loogson/Loogarch fixes
 
 - Allow the core code to retrigger an interrupt that has
   fired while the same interrupt is being handled on another
   CPU, papering over a GICv3 architecture issue
 
 - Work around an integration problem on ASR8601, where the CPU
   numbering isn't representable in the GIC implementation...
 
 - Add some missing interrupt to the STM32 irqchip
 
 - A bunch of warning squashing triggered by W=1 builds
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Merge tag 'irqchip-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates from Marc Zyngier:

  - A number of Loogson/Loogarch fixes

  - Allow the core code to retrigger an interrupt that has
    fired while the same interrupt is being handled on another
    CPU, papering over a GICv3 architecture issue

  - Work around an integration problem on ASR8601, where the CPU
    numbering isn't representable in the GIC implementation...

  - Add some missing interrupt to the STM32 irqchip

  - A bunch of warning squashing triggered by W=1 builds

Link: https://lore.kernel.org/r/20230623224345.3577134-1-maz@kernel.org
2023-06-26 11:05:49 +02:00
James Gowans
7cc148a32f genirq: Expand doc for PENDING and REPLAY flags
Adding a bit more info about what the flags are used for may help future
code readers.

Signed-off-by: James Gowans <jgowans@amazon.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Liao Chang <liaochang1@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230608120021.3273400-2-jgowans@amazon.com
2023-06-16 12:22:05 +01:00
Shanker Donthineni
721255b982 genirq: Use a maple tree for interrupt descriptor management
The current implementation uses a static bitmap for interrupt descriptor
allocation and a radix tree to pointer store the pointer for lookup.

However, the size of the bitmap is constrained by the build time macro
MAX_SPARSE_IRQS, which may not be sufficient to support high-end servers,
particularly those with GICv4.1 hardware, which require a large interrupt
space to cover LPIs and vSGIs.

Replace the bitmap and the radix tree with a maple tree, which not only
stores pointers for lookup, but also provides a mechanism to find free
ranges. That removes the build time hardcoded upper limit.

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230519134902.1495562-4-sdonthineni@nvidia.com
2023-05-24 11:39:44 +02:00
Shanker Donthineni
5e630aa8d9 genirq: Encapsulate sparse bitmap handling
Move the open coded sparse bitmap handling into helper functions as
a preparatory step for converting the sparse interrupt management
to a maple tree.

No functional change.

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230519134902.1495562-3-sdonthineni@nvidia.com
2023-05-24 11:39:44 +02:00
Shanker Donthineni
bc06a9e087 genirq: Use hlist for managing resend handlers
The current implementation utilizes a bitmap for managing interrupt resend
handlers, which is allocated based on the SPARSE_IRQ/NR_IRQS macros.
However, this method may not efficiently utilize memory during runtime,
particularly when IRQ_BITMAP_BITS is large.

Address this issue by using an hlist to manage interrupt resend handlers
instead of relying on a static bitmap memory allocation. Additionally, a
new function, clear_irq_resend(), is introduced and called from
irq_shutdown to ensure a graceful teardown of the interrupt.

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230519134902.1495562-2-sdonthineni@nvidia.com
2023-05-24 11:39:44 +02:00
Yang Yingliang
9049e1ca41 genirq/irqdesc: Don't try to remove non-existing sysfs files
Fault injection tests trigger warnings like this:

  kernfs: can not remove 'chip_name', no directory
  WARNING: CPU: 0 PID: 253 at fs/kernfs/dir.c:1616 kernfs_remove_by_name_ns+0xce/0xe0
  RIP: 0010:kernfs_remove_by_name_ns+0xce/0xe0
  Call Trace:
   <TASK>
   remove_files.isra.1+0x3f/0xb0
   sysfs_remove_group+0x68/0xe0
   sysfs_remove_groups+0x41/0x70
   __kobject_del+0x45/0xc0
   kobject_del+0x29/0x40
   free_desc+0x42/0x70
   irq_free_descs+0x5e/0x90

The reason is that the interrupt descriptor sysfs handling does not roll
back on a failing kobject_add() during allocation. If the descriptor is
freed later on, kobject_del() is invoked with a not added kobject resulting
in the above warnings.

A proper rollback in case of a kobject_add() failure would be the straight
forward solution. But this is not possible due to the way how interrupt
descriptor sysfs handling works.

Interrupt descriptors are allocated before sysfs becomes available. So the
sysfs files for the early allocated descriptors are added later in the boot
process. At this point there can be nothing useful done about a failing
kobject_add(). For consistency the interrupt descriptor allocation always
treats kobject_add() failures as non-critical and just emits a warning.

To solve this problem, keep track in the interrupt descriptor whether
kobject_add() was successful or not and make the invocation of
kobject_del() conditional on that.

[ tglx: Massage changelog, comments and use a state bit. ]

Fixes: ecb3f394c5 ("genirq: Expose interrupt information through sysfs")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20221128151612.1786122-1-yangyingliang@huawei.com
2022-11-30 14:52:11 +01:00
Thomas Pfaff
8707898e22 genirq: Synchronize interrupt thread startup
A kernel hang can be observed when running setserial in a loop on a kernel
with force threaded interrupts. The sequence of events is:

   setserial
     open("/dev/ttyXXX")
       request_irq()
     do_stuff()
      -> serial interrupt
         -> wake(irq_thread)
	      desc->threads_active++;
     close()
       free_irq()
         kthread_stop(irq_thread)
     synchronize_irq() <- hangs because desc->threads_active != 0

The thread is created in request_irq() and woken up, but does not get on a
CPU to reach the actual thread function, which would handle the pending
wake-up. kthread_stop() sets the should stop condition which makes the
thread immediately exit, which in turn leaves the stale threads_active
count around.

This problem was introduced with commit 519cc8652b, which addressed a
interrupt sharing issue in the PCIe code.

Before that commit free_irq() invoked synchronize_irq(), which waits for
the hard interrupt handler and also for associated threads to complete.

To address the PCIe issue synchronize_irq() was replaced with
__synchronize_hardirq(), which only waits for the hard interrupt handler to
complete, but not for threaded handlers.

This was done under the assumption, that the interrupt thread already
reached the thread function and waits for a wake-up, which is guaranteed to
be handled before acting on the stop condition. The problematic case, that
the thread would not reach the thread function, was obviously overlooked.

Make sure that the interrupt thread is really started and reaches
thread_fn() before returning from __setup_irq().

This utilizes the existing wait queue in the interrupt descriptor. The
wait queue is unused for non-shared interrupts. For shared interrupts the
usage might cause a spurious wake-up of a waiter in synchronize_irq() or the
completion of a threaded handler might cause a spurious wake-up of the
waiter for the ready flag. Both are harmless and have no functional impact.

[ tglx: Amended changelog ]

Fixes: 519cc8652b ("genirq: Synchronize only with single thread on free_irq()")
Signed-off-by: Thomas Pfaff <tpfaff@pcs.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/552fe7b4-9224-b183-bb87-a8f36d335690@pcs.com
2022-05-05 11:54:05 +02:00
Sebastian Andrzej Siewior
5320eb42de irq: remove unused flags argument from __handle_irq_event_percpu()
The __IRQF_TIMER bit from the flags argument was used in
add_interrupt_randomness() to distinguish the timer interrupt from other
interrupts. This is no longer the case.

Remove the flags argument from __handle_irq_event_percpu().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-01-07 00:25:25 +01:00
Thomas Gleixner
13b90cadfc genirq/chip: Use the first chip in irq_chip_compose_msi_msg()
The documentation of irq_chip_compose_msi_msg() claims that with
hierarchical irq domains the first chip in the hierarchy which has an
irq_compose_msi_msg() callback is chosen. But the code just keeps
iterating after it finds a chip with a compose callback.

The x86 HPET MSI implementation relies on that behaviour, but that does not
make it more correct.

The message should always be composed at the domain which manages the
underlying resource (e.g. APIC or remap table) because that domain knows
about the required layout of the message.

On X86 the following hierarchies exist:

1)   vector -------- PCI/MSI
2)   vector -- IR -- PCI/MSI

The vector domain has a different message format than the IR (remapping)
domain. So obviously the PCI/MSI domain can't compose the message without
having knowledge about the parent domain, which is exactly the opposite of
what hierarchical domains want to achieve.

X86 actually has two different PCI/MSI chips where #1 has a compose
callback and #2 does not. #2 delegates the composition to the remap domain
where it belongs, but #1 does it at the PCI/MSI level.

For the upcoming device MSI support it's necessary to change this and just
let the first domain which can compose the message take care of it. That
way the top level chip does not have to worry about it and the device MSI
code does not need special knowledge about topologies. It just sets the
compose callback to NULL and lets the hierarchy pick the first chip which
has one.

Due to that the attempt to move the compose callback from the direct
delivery PCI/MSI domain to the vector domain made the system fail to boot
with interrupt remapping enabled because in the remapping case
irq_chip_compose_msi_msg() keeps iterating and choses the compose callback
of the vector domain which obviously creates the wrong format for the remap
table.

Break out of the loop when the first irq chip with a compose callback is
found and fixup the HPET code temporarily. That workaround will be removed
once the direct delivery compose callback is moved to the place where it
belongs in the vector domain.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <maz@kernel.org>                                                                                                                                                                                                                                     Link: https://lore.kernel.org/r/20200826112331.047917603@linutronix.de
2020-09-16 16:52:28 +02:00
Thomas Gleixner
acd26bcf36 genirq: Provide interrupt injection mechanism
Error injection mechanisms need a half ways safe way to inject interrupts as
invoking generic_handle_irq() or the actual device interrupt handler
directly from e.g. a debugfs write is not guaranteed to be safe.

On x86 generic_handle_irq() is unsafe due to the hardware trainwreck which
is the base of x86 interrupt delivery and affinity management.

Move the irq debugfs injection code into a separate function which can be
used by error injection code as well.

The implementation prevents at least that state is corrupted, but it cannot
close a very tiny race window on x86 which might result in a stale and not
serviced device interrupt under very unlikely circumstances.

This is explicitly for debugging and testing and not for production use or
abuse in random driver code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lkml.kernel.org/r/20200306130623.990928309@linutronix.de
2020-03-08 11:06:42 +01:00
Thomas Gleixner
1f85b1f5e1 genirq: Add return value to check_irq_resend()
In preparation for an interrupt injection interface which can be used
safely by error injection mechanisms. e.g. PCI-E/ AER, add a return value
to check_irq_resend() so errors can be propagated to the caller.

Split out the software resend code so the ugly #ifdef in check_irq_resend()
goes away and the whole thing becomes readable.

Fix up the caller in debugfs. The caller in irq_startup() does not care
about the return value as this is unconditionally invoked for all
interrupts and the resend is best effort anyway.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lkml.kernel.org/r/20200306130623.775200917@linutronix.de
2020-03-08 11:06:41 +01:00
Thomas Gleixner
c16816acd0 genirq: Add protection against unsafe usage of generic_handle_irq()
In general calling generic_handle_irq() with interrupts disabled from non
interrupt context is harmless. For some interrupt controllers like the x86
trainwrecks this is outright dangerous as it might corrupt state if an
interrupt affinity change is pending.

Add infrastructure which allows to mark interrupts as unsafe and catch such
usage in generic_handle_irq().

Reported-by: sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lkml.kernel.org/r/20200306130623.590923677@linutronix.de
2020-03-08 11:06:40 +01:00
Thomas Gleixner
cba6437a18 genirq/proc: Reject invalid affinity masks (again)
Qian Cai reported that the WARN_ON() in the x86/msi affinity setting code,
which catches cases where the affinity setting is not done on the CPU which
is the current target of the interrupt, triggers during CPU hotplug stress
testing.

It turns out that the warning which was added with the commit addressing
the MSI affinity race unearthed yet another long standing bug.

If user space writes a bogus affinity mask, i.e. it contains no online CPUs,
then it calls irq_select_affinity_usr(). This was introduced for ALPHA in

  eee45269b0 ("[PATCH] Alpha: convert to generic irq framework (generic part)")

and subsequently made available for all architectures in

  1840475676 ("genirq: Expose default irq affinity mask (take 3)")

which introduced the circumvention of the affinity setting restrictions for
interrupt which cannot be moved in process context.

The whole exercise is bogus in various aspects:

  1) If the interrupt is already started up then there is absolutely
     no point to honour a bogus interrupt affinity setting from user
     space. The interrupt is already assigned to an online CPU and it
     does not make any sense to reassign it to some other randomly
     chosen online CPU.

  2) If the interupt is not yet started up then there is no point
     either. A subsequent startup of the interrupt will invoke
     irq_setup_affinity() anyway which will chose a valid target CPU.

So the only correct solution is to just return -EINVAL in case user space
wrote an affinity mask which does not contain any online CPUs, except for
ALPHA which has it's own magic sauce for this.

Fixes: 1840475676 ("genirq: Expose default irq affinity mask (take 3)")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Qian Cai <cai@lca.pw>
Link: https://lkml.kernel.org/r/878sl8xdbm.fsf@nanos.tec.linutronix.de
2020-02-14 09:43:17 +01:00
Linus Torvalds
0902d5011c Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x96 apic updates from Thomas Gleixner:
 "Updates for the x86 APIC interrupt handling and APIC timer:

   - Fix a long standing issue with spurious interrupts which was caused
     by the big vector management rework a few years ago. Robert Hodaszi
     provided finally enough debug data and an excellent initial failure
     analysis which allowed to understand the underlying issues.

     This contains a change to the core interrupt management code which
     is required to handle this correctly for the APIC/IO_APIC. The core
     changes are NOOPs for most architectures except ARM64. ARM64 is not
     impacted by the change as confirmed by Marc Zyngier.

   - Newer systems allow to disable the PIT clock for power saving
     causing panic in the timer interrupt delivery check of the IO/APIC
     when the HPET timer is not enabled either. While the clock could be
     turned on this would cause an endless whack a mole game to chase
     the proper register in each affected chipset.

     These systems provide the relevant frequencies for TSC, CPU and the
     local APIC timer via CPUID and/or MSRs, which allows to avoid the
     PIT/HPET based calibration. As the calibration code is the only
     usage of the legacy timers on modern systems and is skipped anyway
     when the frequencies are known already, there is no point in
     setting up the PIT and actually checking for the interrupt delivery
     via IO/APIC.

     To achieve this on a wide variety of platforms, the CPUID/MSR based
     frequency readout has been made more robust, which also allowed to
     remove quite some workarounds which turned out to be not longer
     required. Thanks to Daniel Drake for analysis, patches and
     verification"

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/irq: Seperate unused system vectors from spurious entry again
  x86/irq: Handle spurious interrupt after shutdown gracefully
  x86/ioapic: Implement irq_get_irqchip_state() callback
  genirq: Add optional hardware synchronization for shutdown
  genirq: Fix misleading synchronize_irq() documentation
  genirq: Delay deactivation in free_irq()
  x86/timer: Skip PIT initialization on modern chipsets
  x86/apic: Use non-atomic operations when possible
  x86/apic: Make apic_bsp_setup() static
  x86/tsc: Set LAPIC timer period to crystal clock frequency
  x86/apic: Rename 'lapic_timer_frequency' to 'lapic_timer_period'
  x86/tsc: Use CPUID.0x16 to calculate missing crystal frequency
2019-07-08 11:22:57 -07:00
Thomas Gleixner
62e0468650 genirq: Add optional hardware synchronization for shutdown
free_irq() ensures that no hardware interrupt handler is executing on a
different CPU before actually releasing resources and deactivating the
interrupt completely in a domain hierarchy.

But that does not catch the case where the interrupt is on flight at the
hardware level but not yet serviced by the target CPU. That creates an
interesing race condition:

   CPU 0                  CPU 1               IRQ CHIP

                                              interrupt is raised
                                              sent to CPU1
			  Unable to handle
			  immediately
			  (interrupts off,
			   deep idle delay)
   mask()
   ...
   free()
     shutdown()
     synchronize_irq()
     release_resources()
                          do_IRQ()
                            -> resources are not available

That might be harmless and just trigger a spurious interrupt warning, but
some interrupt chips might get into a wedged state.

Utilize the existing irq_get_irqchip_state() callback for the
synchronization in free_irq().

synchronize_hardirq() is not using this mechanism as it might actually
deadlock unter certain conditions, e.g. when called with interrupts
disabled and the target CPU is the one on which the synchronization is
invoked. synchronize_irq() uses it because that function cannot be called
from non preemtible contexts as it might sleep.

No functional change intended and according to Marc the existing GIC
implementations where the driver supports the callback should be able
to cope with that core change. Famous last words.

Fixes: 464d12309e ("x86/vector: Switch IOAPIC to global reservation mode")
Reported-by: Robert Hodaszi <Robert.Hodaszi@digi.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20190628111440.279463375@linutronix.de
2019-07-03 10:12:29 +02:00
Thomas Gleixner
4001d8e876 genirq: Delay deactivation in free_irq()
When interrupts are shutdown, they are immediately deactivated in the
irqdomain hierarchy. While this looks obviously correct there is a subtle
issue:

There might be an interrupt in flight when free_irq() is invoking the
shutdown. This is properly handled at the irq descriptor / primary handler
level, but the deactivation might completely disable resources which are
required to acknowledge the interrupt.

Split the shutdown code and deactivate the interrupt after synchronization
in free_irq(). Fixup all other usage sites where this is not an issue to
invoke the combined shutdown_and_deactivate() function instead.

This still might be an issue if the interrupt in flight servicing is
delayed on a remote CPU beyond the invocation of synchronize_irq(), but
that cannot be handled at that level and needs to be handled in the
synchronize_irq() context.

Fixes: f8264e3496 ("irqdomain: Introduce new interfaces to support hierarchy irqdomains")
Reported-by: Robert Hodaszi <Robert.Hodaszi@digi.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20190628111440.098196390@linutronix.de
2019-07-03 10:12:28 +02:00
Daniel Lezcano
df025e47e4 genirq/timings: Encapsulate timings push
For the next patches providing the selftest, it is required to artificially
insert timings value in the circular buffer in order to check the
correctness of the code. Encapsulate the common code between the future
test code and the current code with an always-inline tag.

No functional change.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20190527205521.12091-5-daniel.lezcano@linaro.org
2019-06-12 10:47:04 +02:00
Thomas Gleixner
a324ca9cad irqchip updates for Linux 5.1
- Core pseudo-NMI handling code
 - Allow the default irq domain to be retrieved
 - A new interrupt controller for the Loongson LS1X platform
 - Affinity support for the SiFive PLIC
 - Better support for the iMX irqsteer driver
 - NUMA aware memory allocations for GICv3
 - A handful of other fixes (i8259, GICv3, PLIC)
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Merge tag 'irqchip-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates from Marc Zyngier

- Core pseudo-NMI handling code
- Allow the default irq domain to be retrieved
- A new interrupt controller for the Loongson LS1X platform
- Affinity support for the SiFive PLIC
- Better support for the iMX irqsteer driver
- NUMA aware memory allocations for GICv3
- A handful of other fixes (i8259, GICv3, PLIC)
2019-02-23 10:53:31 +01:00
Thomas Gleixner
1136b07289 genirq: Avoid summation loops for /proc/stat
Waiman reported that on large systems with a large amount of interrupts the
readout of /proc/stat takes a long time to sum up the interrupt
statistics. In principle this is not a problem. but for unknown reasons
some enterprise quality software reads /proc/stat with a high frequency.

The reason for this is that interrupt statistics are accounted per cpu. So
the /proc/stat logic has to sum up the interrupt stats for each interrupt.

This can be largely avoided for interrupts which are not marked as
'PER_CPU' interrupts by simply adding a per interrupt summation counter
which is incremented along with the per interrupt per cpu counter.

The PER_CPU interrupts need to avoid that and use only per cpu accounting
because they share the interrupt number and the interrupt descriptor and
concurrent updates would conflict or require unwanted synchronization.

Reported-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: https://lkml.kernel.org/r/20190208135020.925487496@linutronix.de


8<-------------

v2: Undo the unintentional layout change of struct irq_desc.

 include/linux/irqdesc.h |    1 +
 kernel/irq/chip.c       |   12 ++++++++++--
 kernel/irq/internals.h  |    8 +++++++-
 kernel/irq/irqdesc.c    |    7 ++++++-
 4 files changed, 24 insertions(+), 4 deletions(-)
2019-02-10 21:34:45 +01:00
Julien Thierry
b525903c25 genirq: Provide basic NMI management for interrupt lines
Add functionality to allocate interrupt lines that will deliver IRQs
as Non-Maskable Interrupts. These allocations are only successful if
the irqchip provides the necessary support and allows NMI delivery for the
interrupt line.

Interrupt lines allocated for NMI delivery must be enabled/disabled through
enable_nmi/disable_nmi_nosync to keep their state consistent.

To treat a PERCPU IRQ as NMI, the interrupt must not be shared nor threaded,
the irqchip directly managing the IRQ must be the root irqchip and the
irqchip cannot be behind a slow bus.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-05 14:36:57 +00:00
Thomas Gleixner
1beaeacdc8 genirq: Make legacy autoprobing work again
Meelis reported the following warning on a quad P3 HP NetServer museum piece:

WARNING: CPU: 3 PID: 258 at kernel/irq/chip.c:244 __irq_startup+0x80/0x100
EIP: __irq_startup+0x80/0x100
irq_startup+0x7e/0x170
probe_irq_on+0x128/0x2b0
parport_irq_probe.constprop.18+0x8d/0x1af [parport_pc]
parport_pc_probe_port+0xf11/0x1260 [parport_pc]
parport_pc_init+0x78a/0xf10 [parport_pc]
parport_parse_param.constprop.16+0xf0/0xf0 [parport_pc]
do_one_initcall+0x45/0x1e0

This is caused by the rewrite of the irq activation/startup sequence which
missed to convert a callsite in the irq legacy auto probing code.

To fix this irq_activate_and_startup() needs to gain a return value so the
pending logic can work proper.

Fixes: c942cee46b ("genirq: Separate activation and startup")
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Meelis Roos <mroos@linux.ee>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801301935410.1797@nanos
2018-02-01 11:09:40 +01:00
Thomas Gleixner
702cb0a028 genirq/irqdomain: Rename early argument of irq_domain_activate_irq()
The 'early' argument of irq_domain_activate_irq() is actually used to
denote reservation mode. To avoid confusion, rename it before abuse
happens.

No functional change.

Fixes: 7249164346 ("genirq/irqdomain: Update irq_domain_ops.activate() signature")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexandru Chirvasitu <achirvasub@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Mikael Pettersson <mikpelinux@gmail.com>
Cc: Josh Poulson <jopoulso@microsoft.com>
Cc: Mihai Costache <v-micos@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-pci@vger.kernel.org
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Simon Xiao <sixiao@microsoft.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: devel@linuxdriverproject.org
Cc: KY Srinivasan <kys@microsoft.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Sakari Ailus <sakari.ailus@intel.com>,
Cc: linux-media@vger.kernel.org
2017-12-29 21:13:04 +01:00
Linus Torvalds
670310dfba Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq core updates from Thomas Gleixner:
 "A rather large update for the interrupt core code and the irq chip drivers:

   - Add a new bitmap matrix allocator and supporting changes, which is
     used to replace the x86 vector allocator which comes with separate
     pull request. This allows to replace the convoluted nested loop
     allocation function in x86 with a facility which supports the
     recently added property of managed interrupts proper and allows to
     switch to a best effort vector reservation scheme, which addresses
     problems with vector exhaustion.

   - A large update to the ARM GIC-V3-ITS driver adding support for
     range selectors.

   - New interrupt controllers:
       - Meson and Meson8 GPIO
       - BCM7271 L2
       - Socionext EXIU

     If you expected that this will stop at some point, I have to
     disappoint you. There are new ones posted already. Sigh!

   - STM32 interrupt controller support for new platforms.

   - A pile of fixes, cleanups and updates to the MIPS GIC driver

   - The usual small fixes, cleanups and updates all over the place.
     Most visible one is to move the irq chip drivers Kconfig switches
     into a separate Kconfig menu"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  genirq: Fix type of shifting literal 1 in __setup_irq()
  irqdomain: Drop pointless NULL check in virq_debug_show_one
  genirq/proc: Return proper error code when irq_set_affinity() fails
  irq/work: Use llist_for_each_entry_safe
  irqchip: mips-gic: Print warning if inherited GIC base is used
  irqchip/mips-gic: Add pr_fmt and reword pr_* messages
  irqchip/stm32: Move the wakeup on interrupt mask
  irqchip/stm32: Fix initial values
  irqchip/stm32: Add stm32h7 support
  dt-bindings/interrupt-controllers: Add compatible string for stm32h7
  irqchip/stm32: Add multi-bank management
  irqchip/stm32: Select GENERIC_IRQ_CHIP
  irqchip/exiu: Add support for Socionext Synquacer EXIU controller
  dt-bindings: Add description of Socionext EXIU interrupt controller
  irqchip/gic-v3-its: Fix VPE activate callback return value
  irqchip: mips-gic: Make IPI bitmaps static
  irqchip: mips-gic: Share register writes in gic_set_type()
  irqchip: mips-gic: Remove gic_vpes variable
  irqchip: mips-gic: Use num_possible_cpus() to reserve IPIs
  irqchip: mips-gic: Configure EIC when CPUs come online
  ...
2017-11-13 17:33:11 -08:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Thomas Gleixner
42e1cc2dc5 genirq/irqdomain: Propagate early activation
Propagate the early activation mode to the irqdomain activate()
callbacks. This is required for the upcoming reservation, late vector
assignment scheme, so that the early activation call can act accordingly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213153.028353660@linutronix.de
2017-09-25 20:38:25 +02:00
Thomas Gleixner
bb9b428a5c genirq/irqdomain: Allow irq_domain_activate_irq() to fail
Allow irq_domain_activate_irq() to fail. This is required to support a
reservation and late vector assignment scheme.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.933882227@linutronix.de
2017-09-25 20:38:24 +02:00
Thomas Gleixner
c942cee46b genirq: Separate activation and startup
Activation of an interrupt and startup are currently a combo
functionlity. That works so far, but upcoming changes require a strict
separation because the activation can fail in future.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.754334077@linutronix.de
2017-09-25 20:38:24 +02:00
Thomas Gleixner
457f6d3507 genirq: Make state consistent for !IRQ_DOMAIN_HIERARCHY
In the !IRQ_DOMAIN_HIERARCHY cas the activation stubs are not
setting/clearing the activation status bits. This is not a problem at the
moment, but upcoming changes require a correct status.

Add the set/clear incovations to the stub functions and move them to the
core internal header to avoid duplication and visibility outside the core.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.591985591@linutronix.de
2017-09-25 20:38:23 +02:00
Thomas Gleixner
07557ccb8c genirq/msi: Capture device name for debugfs
For debugging the allocation of unused or potentially leaked interrupt
descriptor it's helpful to have some information about the site which
allocated them. In case of MSI this is simple because the caller hands the
device struct pointer into the domain allocation function.

Duplicate the device name and show it in the debugfs entry of the interrupt
descriptor.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.433038426@linutronix.de
2017-09-25 20:38:22 +02:00
Masahiro Yamada
163616cf2f genirq: Fix for_each_action_of_desc() macro
struct irq_desc does not have a member named "act".  The correct
name is "action".

Currently, all users of this macro use an iterator named "action".
If a different name is used, it will cause a build error.

Fixes: f944b5a7af ("genirq: Use a common macro to go through the actions list")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1502260341-28184-1-git-send-email-yamada.masahiro@socionext.com
2017-08-14 12:10:37 +02:00
Juergen Gross
a696712c3d genirq/PM: Properly pretend disabled state when force resuming interrupts
Interrupts with the IRQF_FORCE_RESUME flag set have also the
IRQF_NO_SUSPEND flag set. They are not disabled in the suspend path, but
must be forcefully resumed. That's used by XEN to keep IPIs enabled beyond
the suspension of device irqs. Force resume works by pretending that the
interrupt was disabled and then calling __irq_enable().

Incrementing the disabled depth counter was enough to do that, but with the
recent changes which use state flags to avoid unnecessary hardware access,
this is not longer sufficient. If the state flags are not set, then the
hardware callbacks are not invoked and the interrupt line stays disabled in
"hardware".

Set the disabled and masked state when pretending that an interrupt got
disabled by suspend.

Fixes: bf22ff45be ("genirq: Avoid unnecessary low level irq function calls")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Link: http://lkml.kernel.org/r/20170717174703.4603-2-jgross@suse.com
2017-07-17 22:32:20 +02:00
Sebastian Ott
e5682b4eec genirq/debugfs: Fix build for !CONFIG_IRQ_DOMAIN
Fix this build error:

kernel/irq/internals.h:440:20: error: inlining failed in call to always_inline
  'irq_domain_debugfs_init': function body not available
kernel/irq/debugfs.c:202:2: note: called from here
  irq_domain_debugfs_init(root_dir);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1707041124000.1712@schleppi
2017-07-04 12:36:43 +02:00
Daniel Lezcano
e1c9214955 genirq/timings: Add infrastructure for estimating the next interrupt arrival time
An interrupt behaves with a burst of activity with periodic interval of time
followed by one or two peaks of longer interval.

As the time intervals are periodic, statistically speaking they follow a normal
distribution and each interrupts can be tracked individually.

Add a mechanism to compute the statistics on all interrupts, except the
timers which are deterministic from a prediction point of view, as their
expiry time is known.

The goal is to extract the periodicity for each interrupt, with the last
timestamp and sum them, so the next event can be predicted to a certain
extent.

Taking the earliest prediction gives the expected wakeup on the system
(assuming a timer won't expire before).

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1498227072-5980-2-git-send-email-daniel.lezcano@linaro.org
2017-06-24 11:44:39 +02:00
Daniel Lezcano
b2d3d61adb genirq/timings: Add infrastructure to track the interrupt timings
The interrupt framework gives a lot of information about each interrupt. It
does not keep track of when those interrupts occur though, which is a
prerequisite for estimating the next interrupt arrival for power management
purposes.

Add a mechanism to record the timestamp for each interrupt occurrences in a
per-CPU circular buffer to help with the prediction of the next occurrence
using a statistical model.

Each CPU can store up to IRQ_TIMINGS_SIZE events <irq, timestamp>, the
current value of IRQ_TIMINGS_SIZE is 32.

Each event is encoded into a single u64, where the high 48 bits are used
for the timestamp and the low 16 bits are for the irq number.

A static key is introduced so when the irq prediction is switched off at
runtime, the overhead is near to zero.

It results in most of the code in internals.h for inline reasons and a very
few in the new file timings.c. The latter will contain more in the next patch
which will provide the statistical model for the next event prediction.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1498227072-5980-1-git-send-email-daniel.lezcano@linaro.org
2017-06-24 11:44:11 +02:00
Thomas Gleixner
c2ce34c0a0 genirq/debugfs: Remove pointless NULL pointer check
debugfs_remove() has it's own NULL pointer check. Remove the conditional
and make irq_remove_debugfs_entry() an inline helper

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-06-24 11:43:53 +02:00
Thomas Gleixner
4cde9c6b82 genirq: Add force argument to irq_startup()
In order to handle managed interrupts gracefully on irq_startup() so they
won't lose their assigned affinity, it's necessary to allow startups which
keep the interrupts in managed shutdown state, if none of the assigend CPUs
is online. This allows drivers to request interrupts w/o the CPUs being
online, which avoid online/offline churn in drivers.

Add a force argument which can override that decision and let only
request_irq() and enable_irq() allow the managed shutdown
handling. enable_irq() is required, because the interrupt might be
requested with IRQF_NOAUTOEN and enable_irq() invokes irq_startup() which
would then wreckage the assignment again. All other callers force startup
and potentially break the assigned affinity.

No functional change as this only adds the function argument.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235447.112094565@linutronix.de
2017-06-22 18:21:24 +02:00
Thomas Gleixner
54fdf6a087 genirq: Introduce IRQD_MANAGED_SHUTDOWN
Affinity managed interrupts should keep their assigned affinity accross CPU
hotplug. To avoid magic hackery in device drivers, the core code shall
manage them transparently. This will set these interrupts into a managed
shutdown state when the last CPU of the assigned affinity mask goes
offline. The interrupt will be restarted when one of the CPUs in the
assigned affinity mask comes back online.

Introduce the necessary state flag and the accessor functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.954523476@linutronix.de
2017-06-22 18:21:23 +02:00
Thomas Gleixner
36d84fb451 genirq: Move irq_fixup_move_pending() to core
Now that x86 uses the generic code, the function declaration and inline
stub can move to the core internal header.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235445.928156166@linutronix.de
2017-06-22 18:21:19 +02:00
Thomas Gleixner
f0383c24b4 genirq/cpuhotplug: Add support for cleaning up move in progress
In order to move x86 to the generic hotplug migration code, add support for
cleaning up move in progress bits.

On architectures which have this x86 specific (mis)feature not enabled,
this is optimized out by the compiler.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235445.525817311@linutronix.de
2017-06-22 18:21:17 +02:00
Christoph Hellwig
137221df69 genirq: Move pending helpers to internal.h
So that the affinity code can reuse them.


Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170619235445.109426284@linutronix.de
2017-06-22 18:21:15 +02:00
Thomas Gleixner
43564bd97d genirq: Rename setup_affinity() to irq_setup_affinity()
Rename it with a proper irq_ prefix and make it available for other files
in the core code. Preparatory patch for moving the irq affinity setup
around.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235444.928501004@linutronix.de
2017-06-22 18:21:14 +02:00
Thomas Gleixner
cba4235e60 genirq: Remove mask argument from setup_affinity()
No point to have this alloc/free dance of cpumasks. Provide a static mask
for setup_affinity() and protect it proper.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235444.851571573@linutronix.de
2017-06-22 18:21:14 +02:00
Thomas Gleixner
087cdfb662 genirq/debugfs: Add proper debugfs interface
Debugging (hierarchical) interupt domains is tedious as there is no
information about the hierarchy and no information about states of
interrupts in the various domain levels.

Add a debugfs directory 'irq' and subdirectories 'domains' and 'irqs'.

The domains directory contains the domain files. The content is information
about the domain. If the domain is part of a hierarchy then the parent
domains are printed as well.

# ls /sys/kernel/debug/irq/domains/
default     INTEL-IR-2	    INTEL-IR-MSI-2  IO-APIC-IR-2  PCI-MSI
DMAR-MSI    INTEL-IR-3	    INTEL-IR-MSI-3  IO-APIC-IR-3  unknown-1
INTEL-IR-0  INTEL-IR-MSI-0  IO-APIC-IR-0    IO-APIC-IR-4  VECTOR
INTEL-IR-1  INTEL-IR-MSI-1  IO-APIC-IR-1    PCI-HT

# cat /sys/kernel/debug/irq/domains/VECTOR 
name:   VECTOR
 size:   0
 mapped: 216
 flags:  0x00000041

# cat /sys/kernel/debug/irq/domains/IO-APIC-IR-0 
name:   IO-APIC-IR-0
 size:   24
 mapped: 19
 flags:  0x00000041
 parent: INTEL-IR-3
    name:   INTEL-IR-3
     size:   65536
     mapped: 167
     flags:  0x00000041
     parent: VECTOR
        name:   VECTOR
         size:   0
         mapped: 216
         flags:  0x00000041

Unfortunately there is no per cpu information about the VECTOR domain (yet).

The irqs directory contains detailed information about mapped interrupts.

# cat /sys/kernel/debug/irq/irqs/3
handler:  handle_edge_irq
status:   0x00004000
istate:   0x00000000
ddepth:   1
wdepth:   0
dstate:   0x01018000
            IRQD_IRQ_DISABLED
            IRQD_SINGLE_TARGET
            IRQD_MOVE_PCNTXT
node:     0
affinity: 0-143
effectiv: 0
pending:  
domain:  IO-APIC-IR-0
 hwirq:   0x3
 chip:    IR-IO-APIC
  flags:   0x10
             IRQCHIP_SKIP_SET_WAKE
 parent:
    domain:  INTEL-IR-3
     hwirq:   0x20000
     chip:    INTEL-IR
      flags:   0x0
     parent:
        domain:  VECTOR
         hwirq:   0x3
         chip:    APIC
          flags:   0x0

This was developed to simplify the debugging of the managed affinity
changes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235444.537566163@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-06-22 18:21:13 +02:00
Bartosz Golaszewski
f160203986 irq/generic-chip: Export irq_init_generic_chip() locally
This function will be used in the devres variant of
irq_alloc_generic_chip().

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Link: http://lkml.kernel.org/r/1496246820-13250-4-git-send-email-brgl@bgdev.pl
2017-06-21 15:53:11 +02:00
Thomas Gleixner
8658be133b Merge branch 'irq/for-block' into irq/core
Pull the irq affinity managing code which is in a seperate branch for block
developers to pull.
2016-07-04 12:26:05 +02:00