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genirq-update-kerneldoc.patch
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
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Thomas Gleixner committed Oct 12, 2010
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84 changes: 52 additions & 32 deletions Documentation/DocBook/genericirq.tmpl
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</authorgroup>

<copyright>
<year>2005-2006</year>
<year>2005-2010</year>
<holder>Thomas Gleixner</holder>
</copyright>
<copyright>
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<listitem><para>Edge type</para></listitem>
<listitem><para>Simple type</para></listitem>
</itemizedlist>
During the implementation we identified another type:
<itemizedlist>
<listitem><para>Fast EOI type</para></listitem>
</itemizedlist>
In the SMP world of the __do_IRQ() super-handler another type
was identified:
<itemizedlist>
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is still available. This leads to a kind of duality for the time
being. Over time the new model should be used in more and more
architectures, as it enables smaller and cleaner IRQ subsystems.
It's deprecated for three years now and about to be removed.
</para>
</chapter>
<chapter id="bugs">
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<itemizedlist>
<listitem><para>handle_level_irq</para></listitem>
<listitem><para>handle_edge_irq</para></listitem>
<listitem><para>handle_fasteoi_irq</para></listitem>
<listitem><para>handle_simple_irq</para></listitem>
<listitem><para>handle_percpu_irq</para></listitem>
</itemizedlist>
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are used by the default flow implementations.
The following helper functions are implemented (simplified excerpt):
<programlisting>
default_enable(irq)
default_enable(struct irq_data *data)
{
desc->chip->unmask(irq);
desc->chip->irq_unmask(data);
}

default_disable(irq)
default_disable(struct irq_data *data)
{
if (!delay_disable(irq))
desc->chip->mask(irq);
if (!delay_disable(data))
desc->chip->irq_mask(data);
}

default_ack(irq)
default_ack(struct irq_data *data)
{
chip->ack(irq);
chip->irq_ack(data);
}

default_mask_ack(irq)
default_mask_ack(struct irq_data *data)
{
if (chip->mask_ack) {
chip->mask_ack(irq);
if (chip->irq_mask_ack) {
chip->irq_mask_ack(data);
} else {
chip->mask(irq);
chip->ack(irq);
chip->irq_mask(data);
chip->irq_ack(data);
}
}

noop(irq)
noop(struct irq_data *data))
{
}

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<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
desc->chip->start();
desc->chip->irq_mask();
handle_IRQ_event(desc->action);
desc->chip->end();
desc->chip->irq_unmask();
</programlisting>
</para>
</sect3>
</sect3>
<sect3 id="Default_FASTEOI_IRQ_flow_handler">
<title>Default Fast EOI IRQ flow handler</title>
<para>
handle_fasteoi_irq provides a generic implementation
for interrupts, which only need an EOI at the end of
the handler
</para>
<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
handle_IRQ_event(desc->action);
desc->chip->irq_eoi();
</programlisting>
</para>
</sect3>
<sect3 id="Default_Edge_IRQ_flow_handler">
<title>Default Edge IRQ flow handler</title>
<para>
Expand All @@ -294,20 +315,19 @@ desc->chip->end();
The following control flow is implemented (simplified excerpt):
<programlisting>
if (desc->status &amp; running) {
desc->chip->hold();
desc->chip->irq_mask();
desc->status |= pending | masked;
return;
}
desc->chip->start();
desc->chip->irq_ack();
desc->status |= running;
do {
if (desc->status &amp; masked)
desc->chip->enable();
desc->chip->irq_unmask();
desc->status &amp;= ~pending;
handle_IRQ_event(desc->action);
} while (status &amp; pending);
desc->status &amp;= ~running;
desc->chip->end();
</programlisting>
</para>
</sect3>
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<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
desc->chip->start();
handle_IRQ_event(desc->action);
desc->chip->end();
if (desc->chip->irq_eoi)
desc->chip->irq_eoi();
</programlisting>
</para>
</sect3>
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mechanism. (It's necessary to enable CONFIG_HARDIRQS_SW_RESEND when
you want to use the delayed interrupt disable feature and your
hardware is not capable of retriggering an interrupt.)
The delayed interrupt disable can be runtime enabled, per interrupt,
by setting the IRQ_DELAYED_DISABLE flag in the irq_desc status field.
The delayed interrupt disable is not configurable.
</para>
</sect2>
</sect1>
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contains all the direct chip relevant functions, which
can be utilized by the irq flow implementations.
<itemizedlist>
<listitem><para>ack()</para></listitem>
<listitem><para>mask_ack() - Optional, recommended for performance</para></listitem>
<listitem><para>mask()</para></listitem>
<listitem><para>unmask()</para></listitem>
<listitem><para>retrigger() - Optional</para></listitem>
<listitem><para>set_type() - Optional</para></listitem>
<listitem><para>set_wake() - Optional</para></listitem>
<listitem><para>irq_ack()</para></listitem>
<listitem><para>irq_mask_ack() - Optional, recommended for performance</para></listitem>
<listitem><para>irq_mask()</para></listitem>
<listitem><para>irq_unmask()</para></listitem>
<listitem><para>irq_retrigger() - Optional</para></listitem>
<listitem><para>irq_set_type() - Optional</para></listitem>
<listitem><para>irq_set_wake() - Optional</para></listitem>
</itemizedlist>
These primitives are strictly intended to mean what they say: ack means
ACK, masking means masking of an IRQ line, etc. It is up to the flow
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<para>
This chapter contains the autogenerated documentation of the internal functions.
</para>
!Ikernel/irq/irqdesc.c
!Ikernel/irq/handle.c
!Ikernel/irq/chip.c
</chapter>
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