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authorJiri Slaby (SUSE) <jirislaby@kernel.org>2025-03-19 10:29:48 +0100
committerThomas Gleixner <tglx@linutronix.de>2025-05-16 21:06:13 +0200
commit95cfac1b2f85ed883b1748d7955e00f0980c1bb3 (patch)
tree59eab234de8f6e0dee6faf3e5dda574a9bbdaf8d
parent225942f06e93dc4c24ce50df92e0eb5bcd2afbac (diff)
Documentation: irq-domain.rst: Simple improvements
The improvements include: * Capitals in headlines. * Add commas: for easier reading, it is always desired to add commas at some places in text. Like before adverbs or after fronted sentences. * 3rd person -> add 's' to verbs. * End some sentences with period and start a new one. Avoid thus heavy sentences. [ tglx: Fix up subject prefix ] Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250319092951.37667-56-jirislaby@kernel.org
-rw-r--r--Documentation/core-api/irq/irq-domain.rst22
1 files changed, 11 insertions, 11 deletions
diff --git a/Documentation/core-api/irq/irq-domain.rst b/Documentation/core-api/irq/irq-domain.rst
index c365c3ed4eba..cb25649d0bb7 100644
--- a/Documentation/core-api/irq/irq-domain.rst
+++ b/Documentation/core-api/irq/irq-domain.rst
@@ -1,19 +1,19 @@
===============================================
-The irq_domain interrupt number mapping library
+The irq_domain Interrupt Number Mapping Library
===============================================
The current design of the Linux kernel uses a single large number
space where each separate IRQ source is assigned a different number.
This is simple when there is only one interrupt controller, but in
-systems with multiple interrupt controllers the kernel must ensure
+systems with multiple interrupt controllers, the kernel must ensure
that each one gets assigned non-overlapping allocations of Linux
IRQ numbers.
The number of interrupt controllers registered as unique irqchips
-show a rising tendency: for example subdrivers of different kinds
+shows a rising tendency. For example, subdrivers of different kinds
such as GPIO controllers avoid reimplementing identical callback
mechanisms as the IRQ core system by modelling their interrupt
-handlers as irqchips, i.e. in effect cascading interrupt controllers.
+handlers as irqchips. I.e. in effect cascading interrupt controllers.
Here the interrupt number loose all kind of correspondence to
hardware interrupt numbers: whereas in the past, IRQ numbers could
@@ -21,15 +21,15 @@ be chosen so they matched the hardware IRQ line into the root
interrupt controller (i.e. the component actually fireing the
interrupt line to the CPU) nowadays this number is just a number.
-For this reason we need a mechanism to separate controller-local
-interrupt numbers, called hardware irq's, from Linux IRQ numbers.
+For this reason, we need a mechanism to separate controller-local
+interrupt numbers, called hardware IRQs, from Linux IRQ numbers.
The irq_alloc_desc*() and irq_free_desc*() APIs provide allocation of
irq numbers, but they don't provide any support for reverse mapping of
the controller-local IRQ (hwirq) number into the Linux IRQ number
space.
-The irq_domain library adds mapping between hwirq and IRQ numbers on
+The irq_domain library adds a mapping between hwirq and IRQ numbers on
top of the irq_alloc_desc*() API. An irq_domain to manage mapping is
preferred over interrupt controller drivers open coding their own
reverse mapping scheme.
@@ -38,7 +38,7 @@ irq_domain also implements translation from an abstract irq_fwspec
structure to hwirq numbers (Device Tree and ACPI GSI so far), and can
be easily extended to support other IRQ topology data sources.
-irq_domain usage
+irq_domain Usage
================
An interrupt controller driver creates and registers an irq_domain by
@@ -76,7 +76,7 @@ If the driver has the Linux IRQ number or the irq_data pointer, and
needs to know the associated hwirq number (such as in the irq_chip
callbacks) then it can be directly obtained from irq_data->hwirq.
-Types of irq_domain mappings
+Types of irq_domain Mappings
============================
There are several mechanisms available for reverse mapping from hwirq
@@ -101,7 +101,7 @@ map are fixed time lookup for IRQ numbers, and irq_descs are only
allocated for in-use IRQs. The disadvantage is that the table must be
as large as the largest possible hwirq number.
-The majority of drivers should use the linear map.
+The majority of drivers should use the Linear map.
Tree
----
@@ -189,7 +189,7 @@ that the driver using the simple domain call irq_create_mapping()
before any irq_find_mapping() since the latter will actually work
for the static IRQ assignment case.
-Hierarchy IRQ domain
+Hierarchy IRQ Domain
--------------------
On some architectures, there may be multiple interrupt controllers