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Diffstat (limited to 'Documentation/DocBook/genericirq.tmpl')
| -rw-r--r-- | Documentation/DocBook/genericirq.tmpl | 64 |
1 files changed, 32 insertions, 32 deletions
diff --git a/Documentation/DocBook/genericirq.tmpl b/Documentation/DocBook/genericirq.tmpl index d16d21b7a3b..46347f60335 100644 --- a/Documentation/DocBook/genericirq.tmpl +++ b/Documentation/DocBook/genericirq.tmpl @@ -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> |