Commit ef1417a5 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull leftover IRQ fixes from Ingo Molnar:
 "Two (minor) fixlets that missed v3.12"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Set the irq thread policy without checking CAP_SYS_NICE
  irq: DocBook/genericirq.tmpl: Correct various typos
parents 1006fae3 bbfe65c2
......@@ -87,7 +87,7 @@
<chapter id="rationale">
<title>Rationale</title>
<para>
The original implementation of interrupt handling in Linux is using
The original implementation of interrupt handling in Linux uses
the __do_IRQ() super-handler, which is able to deal with every
type of interrupt logic.
</para>
......@@ -111,19 +111,19 @@
</itemizedlist>
</para>
<para>
This split implementation of highlevel IRQ handlers allows us to
This split implementation of high-level IRQ handlers allows us to
optimize the flow of the interrupt handling for each specific
interrupt type. This reduces complexity in that particular codepath
interrupt type. This reduces complexity in that particular code path
and allows the optimized handling of a given type.
</para>
<para>
The original general IRQ implementation used hw_interrupt_type
structures and their ->ack(), ->end() [etc.] callbacks to
differentiate the flow control in the super-handler. This leads to
a mix of flow logic and lowlevel hardware logic, and it also leads
to unnecessary code duplication: for example in i386, there is a
ioapic_level_irq and a ioapic_edge_irq irq-type which share many
of the lowlevel details but have different flow handling.
a mix of flow logic and low-level hardware logic, and it also leads
to unnecessary code duplication: for example in i386, there is an
ioapic_level_irq and an ioapic_edge_irq IRQ-type which share many
of the low-level details but have different flow handling.
</para>
<para>
A more natural abstraction is the clean separation of the
......@@ -132,23 +132,23 @@
<para>
Analysing a couple of architecture's IRQ subsystem implementations
reveals that most of them can use a generic set of 'irq flow'
methods and only need to add the chip level specific code.
methods and only need to add the chip-level specific code.
The separation is also valuable for (sub)architectures
which need specific quirks in the irq flow itself but not in the
chip-details - and thus provides a more transparent IRQ subsystem
which need specific quirks in the IRQ flow itself but not in the
chip details - and thus provides a more transparent IRQ subsystem
design.
</para>
<para>
Each interrupt descriptor is assigned its own highlevel flow
Each interrupt descriptor is assigned its own high-level flow
handler, which is normally one of the generic
implementations. (This highlevel flow handler implementation also
implementations. (This high-level flow handler implementation also
makes it simple to provide demultiplexing handlers which can be
found in embedded platforms on various architectures.)
</para>
<para>
The separation makes the generic interrupt handling layer more
flexible and extensible. For example, an (sub)architecture can
use a generic irq-flow implementation for 'level type' interrupts
use a generic IRQ-flow implementation for 'level type' interrupts
and add a (sub)architecture specific 'edge type' implementation.
</para>
<para>
......@@ -172,9 +172,9 @@
<para>
There are three main levels of abstraction in the interrupt code:
<orderedlist>
<listitem><para>Highlevel driver API</para></listitem>
<listitem><para>Highlevel IRQ flow handlers</para></listitem>
<listitem><para>Chiplevel hardware encapsulation</para></listitem>
<listitem><para>High-level driver API</para></listitem>
<listitem><para>High-level IRQ flow handlers</para></listitem>
<listitem><para>Chip-level hardware encapsulation</para></listitem>
</orderedlist>
</para>
<sect1 id="Interrupt_control_flow">
......@@ -189,16 +189,16 @@
which are assigned to this interrupt.
</para>
<para>
Whenever an interrupt triggers, the lowlevel arch code calls into
the generic interrupt code by calling desc->handle_irq().
This highlevel IRQ handling function only uses desc->irq_data.chip
Whenever an interrupt triggers, the low-level architecture code calls
into the generic interrupt code by calling desc->handle_irq().
This high-level IRQ handling function only uses desc->irq_data.chip
primitives referenced by the assigned chip descriptor structure.
</para>
</sect1>
<sect1 id="Highlevel_Driver_API">
<title>Highlevel Driver API</title>
<title>High-level Driver API</title>
<para>
The highlevel Driver API consists of following functions:
The high-level Driver API consists of following functions:
<itemizedlist>
<listitem><para>request_irq()</para></listitem>
<listitem><para>free_irq()</para></listitem>
......@@ -216,7 +216,7 @@
</para>
</sect1>
<sect1 id="Highlevel_IRQ_flow_handlers">
<title>Highlevel IRQ flow handlers</title>
<title>High-level IRQ flow handlers</title>
<para>
The generic layer provides a set of pre-defined irq-flow methods:
<itemizedlist>
......@@ -228,7 +228,7 @@
<listitem><para>handle_edge_eoi_irq</para></listitem>
<listitem><para>handle_bad_irq</para></listitem>
</itemizedlist>
The interrupt flow handlers (either predefined or architecture
The interrupt flow handlers (either pre-defined or architecture
specific) are assigned to specific interrupts by the architecture
either during bootup or during device initialization.
</para>
......@@ -297,7 +297,7 @@ desc->irq_data.chip->irq_unmask();
<para>
handle_fasteoi_irq provides a generic implementation
for interrupts, which only need an EOI at the end of
the handler
the handler.
</para>
<para>
The following control flow is implemented (simplified excerpt):
......@@ -394,7 +394,7 @@ if (desc->irq_data.chip->irq_eoi)
The generic functions are intended for 'clean' architectures and chips,
which have no platform-specific IRQ handling quirks. If an architecture
needs to implement quirks on the 'flow' level then it can do so by
overriding the highlevel irq-flow handler.
overriding the high-level irq-flow handler.
</para>
</sect2>
<sect2 id="Delayed_interrupt_disable">
......@@ -419,9 +419,9 @@ if (desc->irq_data.chip->irq_eoi)
</sect2>
</sect1>
<sect1 id="Chiplevel_hardware_encapsulation">
<title>Chiplevel hardware encapsulation</title>
<title>Chip-level hardware encapsulation</title>
<para>
The chip level hardware descriptor structure irq_chip
The chip-level hardware descriptor structure irq_chip
contains all the direct chip relevant functions, which
can be utilized by the irq flow implementations.
<itemizedlist>
......@@ -429,14 +429,14 @@ if (desc->irq_data.chip->irq_eoi)
<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_eoi() - Optional, required for eoi flow handlers</para></listitem>
<listitem><para>irq_eoi() - Optional, required for EOI flow handlers</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
handler(s) to use these basic units of lowlevel functionality.
handler(s) to use these basic units of low-level functionality.
</para>
</sect1>
</chapter>
......@@ -445,7 +445,7 @@ if (desc->irq_data.chip->irq_eoi)
<title>__do_IRQ entry point</title>
<para>
The original implementation __do_IRQ() was an alternative entry
point for all types of interrupts. It not longer exists.
point for all types of interrupts. It no longer exists.
</para>
<para>
This handler turned out to be not suitable for all
......@@ -468,11 +468,11 @@ if (desc->irq_data.chip->irq_eoi)
<chapter id="genericchip">
<title>Generic interrupt chip</title>
<para>
To avoid copies of identical implementations of irq chips the
To avoid copies of identical implementations of IRQ chips the
core provides a configurable generic interrupt chip
implementation. Developers should check carefuly whether the
generic chip fits their needs before implementing the same
functionality slightly different themself.
functionality slightly differently themselves.
</para>
!Ekernel/irq/generic-chip.c
</chapter>
......
......@@ -956,7 +956,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
goto out_mput;
}
sched_setscheduler(t, SCHED_FIFO, &param);
sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
/*
* We keep the reference to the task struct even if
......
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