From nobody Wed Dec 17 08:53:04 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C567D25F963; Wed, 19 Mar 2025 09:33:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742376803; cv=none; b=gg6hTajHcX66YU6TVBqNLbNnIIX2vBxACOJfOr2zdwlUrO5YZ9s/R9X0cxOAKfBRuQ/Hg6zG8Qp/LhBhreeIDsEIYZrKk7VpyTng5WeJKN5v8i2bp5vnMRk9YeECiNACpXjbcqFKz7+B6mJT0Feb4gijRn5XZ/S5Za46P9dZCc4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742376803; c=relaxed/simple; bh=UFLfqYAPRyP0zMZMJni7dgt7MkfzfaxNTSDWCN3V7Ag=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fMDCSp2fysW/67RdKjhCt71aetmxaWSjSiqrWTZtQYP3b1dJGZSIveolsC8z1eWiwxUo04CpHzQpkX6HuWVwUOYazxGQmb+yJOI3Rwja0uSibF8/ud6ZNx91DrtXhJibuGTOrN0aZCw6ULRD9w0ZRcOEZdron9KDYCHpOedO5LI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JVQw6HEW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JVQw6HEW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16957C4CEEA; Wed, 19 Mar 2025 09:33:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742376803; bh=UFLfqYAPRyP0zMZMJni7dgt7MkfzfaxNTSDWCN3V7Ag=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JVQw6HEWw/rNx703pdxYurP52goB6uxBLpnpc5pizQMLD4cFfgGh4VTW3MwkHPaeE tRgDw+2X9d2y6C6XBO0pR0a8uRrT6nDSTeSXLhHNz1gVTy+J78/2T3xHyzVXiYF/nb 7F6LXUB1shDH1FdcBk13Df8wW1zvQ1RtGriE9KiMod2xEXC47L+gco+ht3Sqh0s4gS bR/tzuFzxzG+foF+eMGm3ptEtyd3Tjoeg45VNYR7nuFYKSZfZ8ToF/yUGz09j+tuVL 83C2LQT8hshQ2QM13QmfoWBrlffWCrbWSE5RZBYG9uBRdtbIX8ElC4jNZHJiXvhRnN a7H19bndOizHA== From: "Jiri Slaby (SUSE)" To: tglx@linutronix.de Cc: maz@kernel.org, linux-kernel@vger.kernel.org, "Jiri Slaby (SUSE)" , Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap Subject: [PATCH v2 55/57] docs: irq-domain.rst: Simple improvements Date: Wed, 19 Mar 2025 10:29:48 +0100 Message-ID: <20250319092951.37667-56-jirislaby@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250319092951.37667-1-jirislaby@kernel.org> References: <20250319092951.37667-1-jirislaby@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The improvements include: * Capitals in headlines. * Added 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. Signed-off-by: Jiri Slaby (SUSE) Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Cc: Randy Dunlap --- Documentation/core-api/irq/irq-domain.rst | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/Documentation/core-api/irq/irq-domain.rst b/Documentation/core= -api/irq/irq-domain.rst index 775dd43b3340..c2f2728b1a35 100644 --- a/Documentation/core-api/irq/irq-domain.rst +++ b/Documentation/core-api/irq/irq-domain.rst @@ -1,19 +1,19 @@ =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D -The irq_domain interrupt number mapping library +The irq_domain Interrupt Number Mapping Library =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 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. =20 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. =20 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 th= e root interrupt controller (i.e. the component actually fireing the interrupt line to the CPU) nowadays this number is just a number. =20 -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. =20 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. =20 -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 i= rq_fwspec structure to hwirq numbers (Device Tree and ACPI GSI so far), and can be easily extended to support other IRQ topology data sources. =20 -irq_domain usage +irq_domain Usage =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 An interrupt controller driver creates and registers an irq_domain by @@ -77,7 +77,7 @@ If the driver has the Linux IRQ number or the irq_data po= inter, 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. =20 -Types of irq_domain mappings +Types of irq_domain Mappings =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D =20 There are several mechanisms available for reverse mapping from hwirq @@ -102,7 +102,7 @@ map are fixed time lookup for IRQ numbers, and irq_desc= s are only allocated for in-use IRQs. The disadvantage is that the table must be as large as the largest possible hwirq number. =20 -The majority of drivers should use the linear map. +The majority of drivers should use the Linear map. =20 Tree ---- @@ -190,7 +190,7 @@ 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. =20 -Hierarchy IRQ domain +Hierarchy IRQ Domain -------------------- =20 On some architectures, there may be multiple interrupt controllers --=20 2.49.0