<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/kernel/irq, branch v4.19.290</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2023-03-11T15:31:52Z</updated>
<entry>
<title>irqdomain: Drop bogus fwspec-mapping error handling</title>
<updated>2023-03-11T15:31:52Z</updated>
<author>
<name>Johan Hovold</name>
<email>johan+linaro@kernel.org</email>
</author>
<published>2023-02-13T10:42:45Z</published>
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<id>urn:sha1:525eb5cb8edfb7014711c2c87827ed17af8872fb</id>
<content type='text'>
commit e3b7ab025e931accdc2c12acf9b75c6197f1c062 upstream.

In case a newly allocated IRQ ever ends up not having any associated
struct irq_data it would not even be possible to dispose the mapping.

Replace the bogus disposal with a WARN_ON().

This will also be used to fix a shared-interrupt mapping race, hence the
CC-stable tag.

Fixes: 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ")
Cc: stable@vger.kernel.org      # 4.8
Tested-by: Hsin-Yi Wang &lt;hsinyi@chromium.org&gt;
Tested-by: Mark-PK Tsai &lt;mark-pk.tsai@mediatek.com&gt;
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-4-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>irqdomain: Fix disassociation race</title>
<updated>2023-03-11T15:31:52Z</updated>
<author>
<name>Johan Hovold</name>
<email>johan+linaro@kernel.org</email>
</author>
<published>2023-02-13T10:42:44Z</published>
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<content type='text'>
commit 3f883c38f5628f46b30bccf090faec054088e262 upstream.

The global irq_domain_mutex is held when mapping interrupts from
non-hierarchical domains but currently not when disposing them.

This specifically means that updates of the domain mapcount is racy
(currently only used for statistics in debugfs).

Make sure to hold the global irq_domain_mutex also when disposing
mappings from non-hierarchical domains.

Fixes: 9dc6be3d4193 ("genirq/irqdomain: Add map counter")
Cc: stable@vger.kernel.org      # 4.13
Tested-by: Hsin-Yi Wang &lt;hsinyi@chromium.org&gt;
Tested-by: Mark-PK Tsai &lt;mark-pk.tsai@mediatek.com&gt;
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-3-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>irqdomain: Fix association race</title>
<updated>2023-03-11T15:31:51Z</updated>
<author>
<name>Johan Hovold</name>
<email>johan+linaro@kernel.org</email>
</author>
<published>2023-02-13T10:42:43Z</published>
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<id>urn:sha1:2dcccf91bc4e9937dccf86c9b1f5026ffd72a80b</id>
<content type='text'>
commit b06730a571a9ff1ba5bd6b20bf9e50e5a12f1ec6 upstream.

The sanity check for an already mapped virq is done outside of the
irq_domain_mutex-protected section which means that an (unlikely) racing
association may not be detected.

Fix this by factoring out the association implementation, which will
also be used in a follow-on change to fix a shared-interrupt mapping
race.

Fixes: ddaf144c61da ("irqdomain: Refactor irq_domain_associate_many()")
Cc: stable@vger.kernel.org      # 3.11
Tested-by: Hsin-Yi Wang &lt;hsinyi@chromium.org&gt;
Tested-by: Mark-PK Tsai &lt;mark-pk.tsai@mediatek.com&gt;
Signed-off-by: Johan Hovold &lt;johan+linaro@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230213104302.17307-2-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>random: remove unused irq_flags argument from add_interrupt_randomness()</title>
<updated>2022-06-25T09:49:01Z</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2021-12-07T12:17:33Z</published>
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<content type='text'>
commit 703f7066f40599c290babdb79dd61319264987e9 upstream.

Since commit
   ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter")

the irq_flags argument is no longer used.

Remove unused irq_flags.

Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Dexuan Cui &lt;decui@microsoft.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: K. Y. Srinivasan &lt;kys@microsoft.com&gt;
Cc: Stephen Hemminger &lt;sthemmin@microsoft.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Wei Liu &lt;wei.liu@kernel.org&gt;
Cc: linux-hyperv@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Acked-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>genirq: Synchronize interrupt thread startup</title>
<updated>2022-05-12T10:20:24Z</updated>
<author>
<name>Thomas Pfaff</name>
<email>tpfaff@pcs.com</email>
</author>
<published>2022-05-02T11:28:29Z</published>
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<id>urn:sha1:99bc5b7098fc8f34c8433bcab9aa9e80ffb5e651</id>
<content type='text'>
commit 8707898e22fd665bc1d7b18b809be4b56ce25bdd upstream.

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()
      -&gt; serial interrupt
         -&gt; wake(irq_thread)
	      desc-&gt;threads_active++;
     close()
       free_irq()
         kthread_stop(irq_thread)
     synchronize_irq() &lt;- hangs because desc-&gt;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 519cc8652b3a, 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: 519cc8652b3a ("genirq: Synchronize only with single thread on free_irq()")
Signed-off-by: Thomas Pfaff &lt;tpfaff@pcs.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/552fe7b4-9224-b183-bb87-a8f36d335690@pcs.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>genirq/msi: Ensure deactivation on teardown</title>
<updated>2021-08-26T12:36:40Z</updated>
<author>
<name>Bixuan Cui</name>
<email>cuibixuan@huawei.com</email>
</author>
<published>2021-05-18T03:31:17Z</published>
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<id>urn:sha1:504a4c1057151a1f1332fb3ce940134db8d6b885</id>
<content type='text'>
commit dbbc93576e03fbe24b365fab0e901eb442237a8a upstream.

msi_domain_alloc_irqs() invokes irq_domain_activate_irq(), but
msi_domain_free_irqs() does not enforce deactivation before tearing down
the interrupts.

This happens when PCI/MSI interrupts are set up and never used before being
torn down again, e.g. in error handling pathes. The only place which cleans
that up is the error handling path in msi_domain_alloc_irqs().

Move the cleanup from msi_domain_alloc_irqs() into msi_domain_free_irqs()
to cure that.

Fixes: f3b0946d629c ("genirq/msi: Make sure PCI MSIs are activated early")
Signed-off-by: Bixuan Cui &lt;cuibixuan@huawei.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210518033117.78104-1-cuibixuan@huawei.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>genirq: Provide IRQCHIP_AFFINITY_PRE_STARTUP</title>
<updated>2021-08-26T12:36:40Z</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2021-07-29T21:51:48Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=cab824f67d7e8f68288d615929dec02607e473ad'/>
<id>urn:sha1:cab824f67d7e8f68288d615929dec02607e473ad</id>
<content type='text'>
commit 826da771291fc25a428e871f9e7fb465e390f852 upstream.

X86 IO/APIC and MSI interrupts (when used without interrupts remapping)
require that the affinity setup on startup is done before the interrupt is
enabled for the first time as the non-remapped operation mode cannot safely
migrate enabled interrupts from arbitrary contexts. Provide a new irq chip
flag which allows affected hardware to request this.

This has to be opt-in because there have been reports in the past that some
interrupt chips cannot handle affinity setting before startup.

Fixes: 18404756765c ("genirq: Expose default irq affinity mask (take 3)")
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Marc Zyngier &lt;maz@kernel.org&gt;
Reviewed-by: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.779791738@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>genirq/matrix: Prevent allocation counter corruption</title>
<updated>2021-05-22T08:59:14Z</updated>
<author>
<name>Vitaly Kuznetsov</name>
<email>vkuznets@redhat.com</email>
</author>
<published>2021-03-19T11:18:23Z</published>
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<id>urn:sha1:873792c84237953385d99ff3c56ed9e467c15300</id>
<content type='text'>
[ Upstream commit c93a5e20c3c2dabef8ea360a3d3f18c6f68233ab ]

When irq_matrix_free() is called for an unallocated vector the
managed_allocated and total_allocated counters get out of sync with the
real state of the matrix. Later, when the last interrupt is freed, these
counters will underflow resulting in UINTMAX because the counters are
unsigned.

While this is certainly a problem of the calling code, this can be catched
in the allocator by checking the allocation bit for the to be freed vector
which simplifies debugging.

An example of the problem described above:
https://lore.kernel.org/lkml/20210318192819.636943062@linutronix.de/

Add the missing sanity check and emit a warning when it triggers.

Suggested-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lore.kernel.org/r/20210319111823.1105248-1-vkuznets@redhat.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>genirq: Disable interrupts for force threaded handlers</title>
<updated>2021-03-24T10:07:38Z</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2021-03-17T14:38:52Z</published>
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<id>urn:sha1:b6e961646de67d2b453dc148a846bd9808537695</id>
<content type='text'>
commit 81e2073c175b887398e5bca6c004efa89983f58d upstream.

With interrupt force threading all device interrupt handlers are invoked
from kernel threads. Contrary to hard interrupt context the invocation only
disables bottom halfs, but not interrupts. This was an oversight back then
because any code like this will have an issue:

thread(irq_A)
  irq_handler(A)
    spin_lock(&amp;foo-&gt;lock);

interrupt(irq_B)
  irq_handler(B)
    spin_lock(&amp;foo-&gt;lock);

This has been triggered with networking (NAPI vs. hrtimers) and console
drivers where printk() happens from an interrupt which interrupted the
force threaded handler.

Now people noticed and started to change the spin_lock() in the handler to
spin_lock_irqsave() which affects performance or add IRQF_NOTHREAD to the
interrupt request which in turn breaks RT.

Fix the root cause and not the symptom and disable interrupts before
invoking the force threaded handler which preserves the regular semantics
and the usefulness of the interrupt force threading as a general debugging
tool.

For not RT this is not changing much, except that during the execution of
the threaded handler interrupts are delayed until the handler
returns. Vs. scheduling and softirq processing there is no difference.

For RT kernels there is no issue.

Fixes: 8d32a307e4fa ("genirq: Provide forced interrupt threading")
Reported-by: Johan Hovold &lt;johan@kernel.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Johan Hovold &lt;johan@kernel.org&gt;
Acked-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Link: https://lore.kernel.org/r/20210317143859.513307808@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>genirq/msi: Activate Multi-MSI early when MSI_FLAG_ACTIVATE_EARLY is set</title>
<updated>2021-02-10T08:21:07Z</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2021-01-23T12:27:59Z</published>
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<id>urn:sha1:2bc9ccf2cdfdbd1e2bcab4114d44a09b61d59a7a</id>
<content type='text'>
commit 4c457e8cb75eda91906a4f89fc39bde3f9a43922 upstream.

When MSI_FLAG_ACTIVATE_EARLY is set (which is the case for PCI),
__msi_domain_alloc_irqs() performs the activation of the interrupt (which
in the case of PCI results in the endpoint being programmed) as soon as the
interrupt is allocated.

But it appears that this is only done for the first vector, introducing an
inconsistent behaviour for PCI Multi-MSI.

Fix it by iterating over the number of vectors allocated to each MSI
descriptor. This is easily achieved by introducing a new
"for_each_msi_vector" iterator, together with a tiny bit of refactoring.

Fixes: f3b0946d629c ("genirq/msi: Make sure PCI MSIs are activated early")
Reported-by: Shameer Kolothum &lt;shameerali.kolothum.thodi@huawei.com&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Tested-by: Shameer Kolothum &lt;shameerali.kolothum.thodi@huawei.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210123122759.1781359-1-maz@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
